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INDIAN HIgHwAyS
`20/-
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LICeNCe tO POSt
wItHOut PRePAymeNt
PubLISHeD ON 23 SePtembeR, 2019
ADvANCe mONtH, OCtObeR, 2019
OCTOBER, 2019
IndIan HIgHways
volume : 47 Number : 10 total Pages : 84
Pasighat-Pangin Section NH-229 in Arunachal Pradesh
edited and Published by Shri S.K. Nirmal, Secretary general, Indian Roads Congress, IRC HQ, Sector-6, R.K. Puram,
Kama Koti marg, New Delhi - 110 022. Printed by Shri S.K. Nirmal on behalf of the Indian Roads Congress
at m/s. Aravali Printers & Publishers Pvt. Ltd.
https://www.irc.nic.in
Indian Highways
Volume : 47 Number : 10 ● october, 2019 ● ISSN 0376-7256
Indian Roads Congress
Founded : On 10th December, 1934
Contents

From the Editor's Desk

From the Desk of Guest Editor

Announcement
7, 8, & 74 - 80

Advertisements
9, 10, 81 & 82

Irc Technical Committee Meeting Schedule for October, 2019
4-5
6
8
Technical Papers

Bituminous Concrete with Waste Plastic - An Experimental Study
11
By Mukesh Saini & Dr. Praveen Aggarwal

Silt Factor for Scour Calculation Around Bridge Foundation
18
By R. K. Dhiman, Vsm

Performance Analysis of Plaxis Models of Stone Columns in Soft Marine Clay
25
By M.Vinoth , P.S. Prasad & U.K. Guru Vittal

MoRT&H Circular
31

Notifications
32
FEEDBACK
Suggestion/Observation on editorial and Technical Papers are welcome and may be sent to IRC Secretariat on
Email-indhighways@gmail.com/dd.irc-morth@gov.in
Publisher & Editor: S.K. Nirmal, Secretary General, IRC
E-mail: secygen.irc@gov.in
Headquarter: IRC Bhawan, Kama Koti Marg, Sector-6, R.K. Puram, New Delhi-110 022.
Phone No.: +91-11-26171548 (Admn.), 23387140 & 23384543 (Membership), 23387759 (Sale),
26185273 (Tech. Papers, Indian Highways and Tech. Committees)
No part of this publication may be reproduced by any means without prior written permission from the Secretary General, IRC.
The responsibility of the contents and the opinions expressed in Indian Highways is exclusively of the author(s) concerned. IRC and the Editor
disclaim responsibility and liability for any statements or opinion, originality of contents and of any copyright violations by the authors. The
opinion expressed in the papers and contents published in the Indian Highways do not necessarily represent the views of the Editor or IRC.
Printed at: M/s Aravali Printers & Publishers Pvt. Ltd., New Delhi-110 020
INDIAN HIGHWAYS
`20
OCTOBER 2019
3
FROM THE EDITOR’S DESK
RESEARCH & DEVELOPMENT IN ROAD SECTOR IN INDIA
The Central Government through MoRTH, MoRD, MoUD, MoS&T and industry have been
sponsoring the research studies in road sector. The basic purpose of research in the road sector is to
achieve resource efficiencies to save on construction and maintenance costs of road projects without
compromise on quality and standards, to achieve increased durability and performance of road assets
being created with use of innovative technologies and materials, to increase the speed of construction
so that benefits of completed road infrastructure projects are available to users in a timely manner.
This also serves as an important input for Indian Roads Congress in evolving Standards, Codes and
Manuals.
The IRC has been playing an active role in the promotion of road research. In October, 1973, the
Highway Research Board (HRB) was set up in IRC for giving undivided attention to research and
development activities. Identification, Monitoring and Research Application (IMRA) Committee looks
after the research work and compiles data of road research work done in the country on yearly basis.
For wider dissemination, the HRB publishes State-of-the-Art Reports, Highway Research Record
and Highway Research Journal. The HRB identifies the R&D requirements of the country. IRC-HRB
with the help of Identification Monitoring & Research Application Committee (IMRA) and Technical
Committees of IRC identify the priority areas and action plan in road sector and thereafter forward
recommendation to the MoRTH.
The Central Road Research Institute (CRRI), New Delhi set up in 1952 is an apex institution for
research in road sector. It is a constituent of the Council of Scientific and Industrial Research (CSIR)
under the aegis of the Ministry of Science and Technology. It has been doing pioneering service to the
road sector. It also provides significant contribution to the Indian Roads Congress (IRC) for formulating
national standards and codes for design, construction and maintenance of roads and bridges.
Some of the state governments have set up their own research centres and labs for undertaking studies
and providing support in quality control. Notable among them are Highway Research Station (HRS)
Chennai (by Government of Tamil Nadu), Maharashtra Engineering Research Institute (MERI),
Nashik (by Government of Maharashtra), Gujarat Engineering Research Institute (GERI), Vadodara
(by Government of Gujarat) and State Level Laboratories (by Government of Assam, Bihar, Uttar
Pradesh) etc. Structural Engineering Research Centre, Chennai – a national level laboratory of CSIR
also provides research support in various aspects of bridge structures. Several academic institutions
including IITs, NITs and Engineering colleges are also undertaking R&D work in several areas of the
road sector.
The NHAI and NRIDA have also supported piloting of promising technologies on the National
Highways and rural roads respectively entrusted to them.
A major push to the R&D effort and standardization in the road sector was given by the MoRTH in
mid-1980’s when for the first time a budget head was created for Standards and Research (S&R) work.
As a result, full-fledged three divisions were created – one for Roads (S&R), one for Bridges (S&R),
4
INDIAN HIGHWAYS
OCTOBER 2019
FROM THE EDITOR’S DESK
one for Traffic and Transportation (S&R). Some work of applied research was taken up as part of
World Bank and the Asian Development Bank Technical Assistance leading to some of the landmark
research achievements in the road sector as a result of the push by the MoRTH. Several research
schemes and studies have continued to be sanctioned and such research studies are entrusted to CRRI
and academic institutions (IITs, NITs, etc.).
The department of Science and Technology also sponsors research schemes to CRRI and academic
institutions. Under the PMGSY, the National Rural Roads Development Agency (NRRDA) have also
taken up some research projects in the recent past and have prepared Guidelines for Technology
Initiatives in Rural Roads for implementation on the ground by the Project Implementation Units of
the State agencies responsible for rural roads.
Investment in road research should be viewed as a long term investment, to put the country on higher
pedestal in the field of highways. Internationally, the allocation for research in highway sector is about
2% of the total investment on roads. The R&D efforts and money spent on relevant research schemes
and development of new technologies pay rich dividends to the economy, as has been the experience
worldwide. In India there is an urgent need to increase these funding. MoRT&H has provided an
outlay of Rs 40.88 crore for R&D for the current year and has sought research proposals from research
and academic institutions for sanction. NHAI has also shown willingness for sponsoring some R&D
schemes.
Often it is seen that research schemes take a lot of time to commence after their identification and
taking the research work to a logical completion also takes considerable time. There is a need to evolve
a strategy to reduce this time period and put R&D activities on a fast track. It is essential to shorten
the time taken in award of the research work and in implementing them by following a comprehensive
monitoring system which should also solve the bottlenecks, when faced, while carrying out research
work. Further, there are many organizations in the country which are involved in the R&D activities.
There is an urgent need to coordinate all these R&D activities to avoid duplication of research work
and their dissemination for effective application of the available results in the field. IRC is making
every possible effort through HRB in coordination and dissemination of R&D works by providing a
platform to HRB during Mid-term and Annual session.
Government of India has recently announced that scope for Corporate Social Responsibility (CSR)
spends of 2% has been expanded to include research grants to institutes engaged in promoting science
and technology research. This is likely to give big push to research and development in the field of
science and technology.
(Sanjay Kumar Nirmal)
Secretary General
INDIAN HIGHWAYS
OCTOBER 2019
5
From the Desk of Guest Editor, DG (RD) & SS, MoRT&H
NEED FOR COORDINATED SYNCHRONIZED DEVELOPMENT
Development of Infrastructure is of utmost necessity to meet the needs and aspirations of the people and
development. Requirement of infrastructure is far exceeding the construction pace for want of adequate
resources i.e. financial resources and to some extent technology and expertise. However, these get
further stressed due to fragmented approach of development. Government has initiated programme for
development of smart cities and even in this programme, proper coordination between various agencies
of development i.e. road, water and sanitation, electricity transmission and domestic supplies, laying
of pipelines for gas, OFC and other utilities is still lacking. It is often seen that road is constructed with
laid down specifications, however while initiating the process for development of the road, there is no
proposal from the other Authorities responsible for providing utilities or deciding a plan of erecting electric
poles, laying water/sewerage pipelines. Often it is seen that as soon as road is constructed, the same is
excavated for providing utilities. Further without consulting the road Authorities, electric poles are erected
haphazardly on shoulders just abutting the carriageway with complete disregard to safety of passengers
or traffic.
It is also seen that afforestation is being done by forest Authorities in lieu of trees cut during development
process especially during road construction. Although there is a laid down policy guidelines for planting
trees along the road side in the RoW, yet with complete disregard to the policy, the authorities involved in
afforestation very often put all the plants just on the shoulders and sometimes stone guards are also placed
around the plants making shoulder completely unavailable, eventually making it highly unsafe for traffic.
Such haphazard plantation not only affects the safety of the traffic but also affect the future development
or widening of highways. Whenever further development/widening of road is required, all these facilities
are shifted requiring unavoidable expenditure.
All the developed Countries have a Central Controlling Authority; whether it is New York or Singapore,
which controls the coordinated development in the City and any developmental work is taken up only
after seeking prior approval of the Central Authority.
Under the circumstances, there is a strong need to form a centralized controlling Authority in each city/
town to formulate a plan of development which is well coordinated with all the Authorities involved in
development process of various infrastructures and utilities and before taking any development activity,
this has to be got approved from the competent authority taking into account development of all other
facilities and future requirement. However until institutional arrangements are introduced, we as Engineers
are duty bound to take consent/view of all other agencies while conceptualizing a Road infrastructure.
Coordinated development will result in huge savings in the resources which would be available for proper
development of additional infrastructure, meeting the requirement of the people at large.
(I.K. Pandey)
6
INDIAN HIGHWAYS
OCTOBER 2019
ANNOUNCEMENT
IRC PT. JAWAHARLAL NEHRU BIRTH CENTENARY AWARD FOR THE YEAR 2018
Nominations are invited in prescribed proforma for the IRC Pt. Jawaharlal Nehru Birth Centenary Award for the year
2018. The last date for receipt of nominations is 25th October, 2019.
For the year 2019 the nominee’s age should not be more than 45 years. The particulars about the award are given
below:
1.
PREAMBLE
This award has been instituted by the IRC during Pt. Jawaharlal Nehru Birth Centenary Year and will be made each year
for outstanding contribution in the field of Highway Engineering.
2.
NATURE OF AWARD
Award will be in the form of medal/Citation certificate and will be made annually for notable and outstanding contribution,
applied or fundamental, in the field of Highway Engineering (including Bridges).
3.
PURPOSE
For recognizing outstanding work in engineering technology, utilization, etc. in the highway sector and encouraging
young and upcoming engineers/scientists in the profession.
4.ELIGIBILITY AND SELECTION OF THE AWARDEE
a.Any Engineer/Scientist or any individual of India who is member/individual associate member of IRC and is
engaged in the field of highway engineering will be eligible for the award.
b.The award will be bestowed on a person who, in the opinion of the Selection Committee constituted by the
Executive Committee, has made conspicuously important and outstanding contribution to Road Development
of the country in the preceding 5 years of the nomination for the award.
5.
The age of nominee shall be less than 45 years on the 31st May of the year in which the nomination is received.
6.The award will be made on the basis of contributions made primarily by work done in India. The criteria for
selection of the contribution for the award will be the following:
i) Important addition, modification or improvement to the available design criteria.
ii)Important contribution to present day knowledge of physicial phenomenon or behaviour of relevance to
engineering practice.
iii) New approach or methodology for utilization of development of new technology or new techniques for solving
problems in applied engineering technology.
iv) Specific contribution made in the following fields:
7.
(a)
(b)
(c)
(d)
(e)
(f)
Investigation Methods
R&D Management
Standardisation
Software Development
Planning
Maintenance
(g)
(h)
(i)
(j)
(k)
(l)
Repairs and Rehabilitation
Environment
Highway Safety
Construction and Management
Protective Works
Traffic Engineering
Nominations
a)Names of candidates may be proposed by or through any member of the IRC Council. Each such nomination shall
be on the basis of proforma, accompanied by detailed statement of work and contribution of the nominee by the
sponsor, and a critical assessment report bringing out the importance of the significant contributions of the nominee
made during the preceding five years. The nominations alongwith copies of work assessment reports is to be sent
to the Secretary General, IRC on or before 25th October, 2019.
b)A candidate once nominated should be considered for a total period of 3 years, if otherwise eligible, unless revised
nomination is received. Once such nomination has been received, the Secretary General, IRC may correspond
directly with the candidate for supplementary information, if necessary.
INDIAN HIGHWAYS
OCTOBER 2019
7
ANNOUNCEMENT
PROFORMA
IRC-PT. JAWAHARLAL NEHRU BIRTH CENTENARY AWARD
(NOMINATION FOR THE YEAR 2018)
1.
Name of the Nominee.
2.
Roll. No. as member of IRC and the year since he is member of IRC.
3.
Discipline under which to be considered.
4.
Date of Birth.
5.
Academic qualifications beginning with Bachelor’s Degree.
6.
Present employment and post held.
7.
(a)Outstanding achievements of the nominee (in about 500 words) during the last 5 years (Attach separate
sheet)
(b)
Benefit derived/anticipated or measurable impact of the work/contribution /achievement.
(c) Assessment by the sponsor of the importance of the contribution (not more than 100 words)
8.
Whether these achievements/contributions have already been recognized for awards by any other body. If so, the
name of the body, the name of award and the year of award may be given.
9.
Other awards/honours already received including fellowships of professional bodies.
10. Papers published, if any (reprints to be enclosed)
11. Names & address of three experts in the area (preferably in India) as possible reference.
(a)
(b)
(c)
Place :____________________________________
Signature­________________________________________
Name & Designation of the Sponsor
(IRC Council Member)
NOTE : Ten copies of the Proforma along with ten copies of the detailed statement of achievement/contribution neatly
typed should be supplied along with reprints of relevant Papers.
IRC Technical Committees Meeting Schedule for October, 2019
8
Date
Day
Time
Name of the Committee
11-10-19
Fri
11.30 AM
Reduction of Carbon Footprint in Road Construction and
Environment Committee (G-3)
12-10-19
Sat
11.00 AM
Bearings, Joints and Appurtenances Committee (B-6)
12-10-19
Sat
11.00 AM
Road Maintenance & Asset Management Committee (H-6)
19-10-19
Sat
10.30 AM
Loads and Stresses Committee (B-2)
19-10-19
Sat
11.00 AM
Hill Roads and Tunnels Committee (H-10)
INDIAN HIGHWAYS
OCTOBER 2019
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INDIAN HIGHWAYS
OCTOBER 2019
9
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10
INDIAN HIGHWAYS
OCTOBER 2019
TECHNICAL PAPER
Bituminous Concrete with Waste PlasticAn Experimental Study
Abstract
Mukesh Saini1
Dr. Praveen Aggarwal2
The research work was carried out to investigate the experimental behaviour of bituminous concrete mix with addition of
waste plastic bottles (Polyethylene Terephthalate (PET)). Optimum bitumen content was determined for conventional mix by
Marshall Method of mix design and found to be 5.51%. Bituminous concrete mixes were prepared with various percentages
of PET (0%, 6%, 8%, 10%, 12% and 14 % of optimum bitumen content) using dry process. Mechanical properties such
as Marshall Stability, Flow, Marshall Quotient, Retained Stability and Indirect Tensile Strength (ITS) were determined for
these mixes. Results show that with increase in quantity of PET, mechanical properties of bituminous concrete mixes improve
initially up to certain extent and the optimum quantity of PET was found to be 10% by weight of optimum bitumen content,
which fulfil the requirement of mechanical properties for modified mixes using waste plastic as per IRC:SP:98-2013. A good
correlation (Coefficient of correlation = 0.959) is observed between Marshall Stability Value and Indirect Tensile Strength for
PET modified mixes. Hence, application of plastic waste in bituminous pavements is environmental friendly solution in terms
of disposal of non-biodegradable waste plastic along with improvement in mechanical properties of bituminous mixes.
1. INTRODUCTION
Economic competitiveness and productivity challenges
for developed and developing countries are the major
problems over last two decade. To achieve economic
competitiveness, manufacturers have turned to making
large vehicles to fulfil the delivery of goods. Recently,
road ministry has raised the legal axle load for various
categories of commercial vehicle by about 25%. So,
heavy vehicles are increasing in radical manner on roads.
The expected life of pavement reduces due to these heavy
vehicles. This problem can be solving, to some extent, by
using high quality material or more effective construction
techniques. Flexible pavements are the most common
type of pavement worldwide with more than 95% of
total road network. Performance of flexible pavement
can be improved with better quality bituminous mixes.
A number of studies conclude that application of waste
plastic in bituminous mixes improves their engineering
properties. There are two techniques of using waste
plastic in bituminous mixes (i) Wet process (Polymer
Modified Bitumen) and (ii) Dry process. In polymer
modified bitumen process, waste plastic is mixed with
bitumen where as in dry process waste plastic is coated
over aggregates before using them in bituminous mixes
(Sangita et al. 2011, IRC:SP:98-2013).
1
2
Research Scholar, E-mail: mukeshsaini512@gmail.com
Professor, E-mail: praveenaggarwal11@gmail.com
The various mechanical properties of bituminous mixes are
affected by type and dose of waste plastic used in bituminous
mixes. Mechanical properties of bituminous mixes improve
due to improvement in physical properties of waste plastic
coated aggregates, in dry process. Further inter-molecular
bonding between bitumen and waste plastic coated aggregate
enhanced strength and thus show significant improvements
in quality of bituminous mixes (Ahmadinia et al. 2011,
Ahmadinia et al. 2012, Sabina et al. 2009).
Asphalt mixes using PET coated aggregate shows
improvement in fatigue resistance, helpful in improving the
life of flexible pavements under heavy loading condition
(against fatigue failure) (Amir et al. 2014).
Bituminous concrete is a high quality material used as
wearing course on flexible pavements with heavy traffic in
India. In the study optimum quantity of bitumen is worked
out in bituminous concrete mix using Marshal Method of
mix design as per MoRT&H, 2013 Specifications.
The main objectives of this experimental work is to
evaluate the effect of waste plastic bottles (Polyethylene
Terephthalate) on the engineering properties of bituminous
concrete mixes, with a view to improve the quality of
bituminous mix along with finding an alternative disposal
of this non- biodegradable waste material.
CED, NIT, Kurukshetra (Haryana)
INDIAN HIGHWAYS
OCTOBER 2019
11
TECHNICAL PAPER
2. MATERIAL USED
Engineering properties of bituminous mix largely depend
upon the physical properties of ingredient material.
Physical properties of material used in the present study
are described in this section.
2.1 Aggregates The locally available aggregates of
13.2mm and 6mm size from Yamunanagar quarry
(Haryana, India), complying Ministry of Road Transport
and Highways (MoRT&H, 2013, India) specification were
used in the present study. Test results on aggregate along
with permissible limit and test standard are compiled in
Table 1.
Table 1 Test Results on Coarse Aggregates
Sr.
No.
Test
1
Grain size analysis
2
3
4
5
6
7
8
MoRT&H, 2013
Specification
Maximum 5% passing
through 0.075 mm sieve
Results
0.6%
Combined Flakiness and Elongation
Indices
Water Absorption
Specific Gravity
Aggregate Impact Value
Los Angles Abrasion Value
Soundness (Sodium Sulphate)
Coating and Stripping of Bitumen
Aggregate Mix
21.55%
0.74%
13.2mm
2.71
6.0mm
2.68
19.65%
23.45%
7.24%
Retained coating
96%
2.2 Bitumen
For the study bitumen sample was collected from IOCL,
Panipat Refinery (Haryana, India) @ Rs. 34.20 per kg.
Method of Test
IS:2386 Part I
Max 35%
IS:2386 Part I
Max 2%
IS:2386 Part III
2.5-3.0
IS:2386 Part III
Max 24%
Max 30%
Max 12%
Minimum retained
coating 95%
IS:2386 Part IV
IS:2386 Part IV
IS:2386 Part V
IS:6241
The sample was tested for various engineering properties
as per Indian Standard. Test results are summarized in
Table 2.
Table 2 Properties of Bitumen
Sr.
Test
No.
1
Specific Gravity of bitumen at 27 °C
2 Penetration (100 gm, 5 seconds at 25° C, 1/10th of mm)
3
Softening point (°C)
4
Absolute Viscosity at 60ºC, (Poises)
5
Ductility at 27° C, (cm)
Grade of Bitumen
2.3 Mineral Filler
Filler material originates from fines in the aggregate
or may be used in the form of cement, lime or ground
rock. Plasticity index should not be greater than 4. This
requirement does not apply, if filler material is lime
or cement. In the present study locally commercially
available hydrated lime of specific gravity 2.25 was used
as mineral filler.
2.4 Modifier
Waste plastic bottles (Polyethylene Terephthalate) collected
12
INDIAN HIGHWAYS
OCTOBER 2019
Results
1.01
53
49
2980
58
Desired as per IS:
73-2013
Min. 45
Min. 47
2400-3600
Min. 40
VG30
Test Method
IS:1202-1978
IS:1203-1978
IS:1205-1978
IS 1206-1978
IS:1208-1978
from local market and shredded in the range of 2.36 mm
to 600 microns (for proper coating over aggregates) was
used in the present study. The specific gravity of modifier
was observed as 1.24.
3.
EXPERIMENTAL WORK
3.1. Marshall Method of Mix Design
Marshal method of mix design is universally accepted
procedure of mix design for high grade bituminous
mixes such as DBM and BC. Optimum bitumen content
TECHNICAL PAPER
is obtained through Marshall Method of mix design.
Number of properties such as stability, flow, percent air
voids, voids filled with bitumen and voids in mineral
aggregates are determined. Bitumen content satisfying the
requirement of all these properties as per MoRT&H, 2013
Specifications is termed as optimum bitumen content.
In the present study same is determined for bituminous
concrete of G-II grading.
3.2. Proportioning of Material
The mechanical and volumetric properties of
bituminous mixes depend upon the proportioning
of material used. The proportioning of aggregate
used in bituminous concrete (Grade – II) was carried
out as per the MoRT&H, 2013 requirement using
analytical method, given in Table 3 & Fig.1 to fulfil
the gradation requirement.
Table 3 Proportioning of Aggregates for Bituminous Concrete (G-II)
Cumulative % by weight of total aggregate passing
Sieve
Size
(mm)
19.0
13.2
9.5
4.75
2.36
1.18
0.600
0.300
0.150
0.075
Designation
Aggregates
13.2 mm
6 mm
A
B
100.0
100.0
97.4
100.0
61.2
100.0
11.9
92.3
1.4
8.1
0.0
2.4
0.0
2.0
0.0
1.8
0.0
1.4
0.0
0.6
Stone Dust
C
Lime
D
100.0
100.0
100.0
95.4
82.1
68.9
61.1
46.4
19.9
7.8
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
96.0
30.0
Gradation
MORT&H, 2013
Specifications
Proportioning
(A: B: C: D)
(34:14:50:2)
Range
Mean
100
90 – 100
70 – 88
53 – 71
42 – 58
34 – 48
26 – 38
18 – 28
12 – 20
4 – 10
100
95
79
62
50
41
32
23
16
7
100
100
87
67
45
37
33
25
12
5
Fig. 1 Gradation Curve of Bituminous Concrete Mix
3.3. Sample Preparation
A total of 1200gm material (coarse aggregates, fine
aggregates and filler) were taken to prepare the Marshall
Mould as per ASTM: D-1559 specification. Bitumen
content was varied in the range of 5.0% to 5.8% with
an increment of 0.2%. Aggregates were heated to 170°C
temperature and bitumen was heated separately to 150°C.
Heated aggregates and bitumen were mixed together to
obtained uniform mix and then filler material and hydrated
lime was mixed. Mixing was continued at 160°C till a
uniform mix was obtained. The mixture was placed in a
marshall mould of 10.16 cm diameter and 7.5 cm height
with a collar and base. The mould was placed in Marshall
Compaction pedestal and compacted with 75 blows of
the hammer. The sample was inverted and other face also
compacted with same number of blows. After compaction,
the collar and base plate were removed. The sample
was allowed to cool at room temperature and extracted
INDIAN HIGHWAYS
OCTOBER 2019
13
TECHNICAL PAPER
by pushing it out of mould by a sample extractor. Three
specimens were prepared for each composition of material
as shown in Fig. 2.
(load and deformation) were recorded in data acquisition
system. The process was repeated at each bitumen content.
The possessed results are shown in Table 4, with the help
of which optimum bitumen content as 5.51 was obtained.
Fig. 2 Marshall Specimens
3.4. Determination of Optimum Bitumen Content
Prepared Marshall Mould were weight in air and water
before keeping them in water bath at 60°C for 30 minutes.
Immediately after taking out the specimen from water bath
and subjected to loading under Marshall loading frame
as shown in Fig.3. Strained control test was performed
Fig. 3 Marshall Loading Frame
at a rate of 50 mm per minute. Stability value and flow
Table 4 Properties of Bituminous Concrete (G-II) Mixes
Sr.
No.
1
2
3
4
5
6
7
8
9
Properties
Marshall stability Value, kN
Flow Value, mm
Theoretical Max. Density , gm/cc
Bulk Density(Gb), gm/cc
Volume of air voids (Vv) , %
Volume of bitumen (Vb) %
Voids in mineral aggregate (VMA), %
Voids filled with bitumen (VFB) %
Optimum bitumen content %
5.0%
12.64
3.46
2.433
2.292
5.79
11.58
17.36
66.73
3.5 Testing with Modifier
Marshall Specimens were prepared with optimum
bitumen content for modified material using dry process.
The modified material used was waste plastic bottle
(Polyethylene Terephthalate) in the range of 6%, 8%,
10%, 12% and 14% of optimum bitumen content and
various mechanical properties such as Marshall Stability,
Flow, Marshall Quotient, Retained Stability and Indirect
Tensile Strength (ITS) were observed and compiled with
IRC:SP: 98-2013 specification as given in Table 5.
14
INDIAN HIGHWAYS
OCTOBER 2019
Bitumen Content in %age
5.2% 5.4% 5.6%
14.36 16.81 15.93
3.53
3.94
3.89
2.426 2.418 2.411
2.283 2.295 2.316
5.87
5.10
3.94
11.99 12.52 13.10
17.87 17.62 17.04
67.22 71.19 77.64
5.51%
5.8%
15.24
3.54
2.403
2.320
3.48
13.59
17.07
79.86
MoRT&H
Specifications
Min. 9.0
2- 4
3-5
>15
65-75
Min. 5.4
Table 5 Requirements for Waste Plastic Modified
Dense Graded Bituminous Mixes
Sr.
Properties
Requirement
No.
1
12.0
2
Marshall Stability minimum
(kN at 60°C)
Marshall Flow (mm at 60°C)
3
Marshall Quotient (kN/mm)
2.5-5
4
Air Voids (%)
3-5
5
Retained Stability (%)
98
2-4
TECHNICAL PAPER
6
Indirect Tensile Strength,
minimum (N/mm2)
0.9
7
Voids in Mineral Aggregates (%)
16
8
Voids Filled with Bitumen (%)
65-75
As per requirement, in addition to conventional Marshall
Test, Flow, Marshall Quotient, Retained Stability and
Indirect Tensile Strength were determined using following
explained procedure.
3.5.1 Flow and marshall quotient tests
To avoid flushing, bleeding and loss of stability sufficient
voids should be provided in bituminous mixes. Flow value
is the deformation of Marshall Specimen at maximum
load. Resistance to permanent deformation, shear stress
and rutting are the parameters of Marshall Quotient (ratio
of stability to flow).
3.5.2. Retained stability test
Stripping is due to aggregates greater affinity towards
water than bitumen and depends on the physic-chemical
force acting on the system. The bituminous mixes with
high void content have a chance of stripping and resulting
in disintegration of surfacing due to loss of internal
cohesion. The damage caused by water can be evaluated
by retained stability value of bituminous mixes.
3.5.3 Indirect tensile strength (ITS) test
Fig. 4 Marshall Stability versus PET Content
Fig. 5 Flow versus PET Content
The tensile characteristics of bituminous mixes are carried
out by Indirect Tensile Strength (ITS) test, which are related
to the cracking properties of the bituminous pavement.
The Indirect Tensile Strength (ITS) of conditioned and
unconditioned specimens was determined using Marshall
Stability Machine. The ITS value was determined using
the following equation
ITS =
Where
Pmax is the maximum load (N), t is the thickness of the
specimen (mm), d is the diameter of the specimen (mm).
The Tensile Strength ratio (TSR) has been calculated
according to AASHTO T283.
The tensile strength ratio (TSR) is calculated as follows:
TSR =
4. RESULT AND DISCUSSION
4.1. Marshall Stability, Flow and Marshall Quotient
Value
Marshall Stability, Flow and Marshall Quotient Value test
result of modified bituminous concrete mixes are shown
in Figs. 4, 5 and 6 respectively.
Fig. 6 Marshall Quotient versus PET Content
PET modified mixes have higher stability as compared
to conventional mixes. Stability values increases
with increase in percentage of PET up to 8% after that
decrease in the stability start, which indicate the reduced
adhesiveness of the mix. The flow value initially increases
with addition of PET up to 8%, but decreases gradually
with increase in percentage of PET. This decrease in flow
value describes the fatigue cracking of bituminous mix
due to the increased stiffness. The Marshall quotient is
maximum at 8% PET which is 18.85% higher as compared
to conventional mixes, which measure the resistance to
permanent deformation, shear stress and rutting.
INDIAN HIGHWAYS
OCTOBER 2019
15
TECHNICAL PAPER
4.2. Retained Stability Value
The ratio of Marshall Stability of bituminous specimen
after conditioning to the identical specimen without
conditioning is known as retained stability value.
Variation of retained stability with PET content is
shown in Fig. 7.
Fig. 9 Tensile Strength Ratio versus PET Content
indicate that PET modified mixes are less susceptible to
moisture damage as compared to conventional mix.
4.4.Correlation between Marshall Stability and
Indirect Tensile Strength (ITS)
Fig. 7 Retained Stability versus PET Content
The moisture susceptibility resistance of PET modified
mixes is more as compared to conventional mixes. The
retained stability as shown in Fig.7, indicates that the mix
containing 10% PET have highest moisture susceptibility
and decrease after 10%, which shows reduced adhesion
between PET coated aggregate and bitumen at higher
percentage of PET.
4.3. Indirect Tensile Strength (ITS) Value
Result of Indirect Tensile Strength and Tensile Strength
Ratio discussed in 3.5.3 of modified bituminous mixes are
shown in Figs. 8 & 9 respectively.
A correlation is developed between Marshall Stability
and Indirect Tensile Strength using SPSS statistical tool.
With the help of developed correlation, Indirect Tensile
Strength can be work out with known Marshall Stability
value. The coefficient of correlation between Marshall
Stability and Indirect Tensile Strength was found to
be 0.959, which shows significant correlation. The
coefficient of correlation between measured and predicted
indirect tensile strength given in Fig. 10 also gives the
good correlation. The equation given below estimates the
Indirect Tensile Strength (ITS) value of PET modified
specimen by inserting the Marshall Stability value.
ITS= 0.016*MS+ 0.614, R2 = 0.959,
Where
MS: Marshall Stability Value (kN)
Fig. 8 Variation of ITS with PET Content
Indirect Tensile Strength (ITS) value of the PET mixes
increases up to 8% PET and decreases after this amount.
This gives that the PET mix is capable of withstanding
higher tensile strains prior to cracking at 8% PET. The
Tensile Strength Ratio (TSR) of PET modified mixes
increase with increase in percentage of PET, which
16
INDIAN HIGHWAYS
OCTOBER 2019
Fig. 10 Correlation between measured and predicted
value of ITS
5. CONCLUSIONS
In the present study Polyethylene Terephthalate (PET)
waste was used as a modifier in bituminous concrete
TECHNICAL PAPER
grade – II. Dry process was adopted for addition of PET and
various mechanical properties such as Marshall Stability,
Flow, Marshall Quotient, Retained Stability and Indirect
Tensile Strength (ITS) were evaluated. Marshall Stability,
Flow and Marshall Quotient are 24.39%, 4.49% and 18.85 %
more as compared to conventional mix at 8% PET content.
Retained stability value is 13.0% more at 10% PET content,
shows improved adhesion between PET coated aggregate
and bitumen. Indirect Tensile Strength (ITS) is 8.13%
more at 8% PET content, which indicate the higher tensile
strain capability prior to cracking. Tensile Strength Ratio is
increasing with increase in PET content, which indicate that
modified mixes are less susceptible to moisture damage as
compared to conventional mix. The appropriate amount of
PET was 10%, which fulfil the requirement for mechanical
properties of an ideal modified bituminous concrete mix.
It can be concluded from the result obtained from SPSS
statistical tool that higher value of R2, gives the significant
correlation between Marshall Stability and Indirect Tensile
Strength. Hence, utilization of waste plastic bottle (PET)
in bituminous pavements using process is environmental
friendly solution with following advantages:
Higher percentage of plastics waste can be use.
Cost of road can be decrease by reducing the
quantity of bitumen.
iii. Strength and performance of the road can be
increase.
iv. Avoid the use of anti stripping agents.
v. Avoid disposal of plastics waste by incineration
and land filling.
vi. Generate jobs for rag pickers.
vii. Value addition to plastics waste.
viii. Develop a technology, which is eco-friendly.
i.
ii.
RECOMMENDATION
The percentage of waste plastic used in bituminous mixes
depends upon the properties of conventional material and
type of waste plastic. IRC:SP:98-2013 code gives the
guidelines that waste plastic can be used @ 6 to 8% by
weight of bitumen content using dry process and bitumen
content can be reduce correspondingly but not mention
clearly for which type of waste plastic. So, there is a need
to study the performance of flexible pavement at higher
percentage of waste plastic, which will be useful in
revision / validation of IRC:SP:98-2013.
REFERENCES
i.
ii.
Sangita, Khan Tabrez Alam, Sabina, Sharma, D.K.
“Effect of Waste Polymer Modifier on the properties of
Bituminous Concrete Mixes” Construction and Building
Materials 25 (2011) @ Elsevier Ltd. pp. 3841–3848.
IRC:SP:98-2013 “ Guidelines for Use of Waste Plastic
in Hot Bituminous Mixes (Dry Process) in Wearing
Course” Indian Roads Congress, New Delhi
iii.
Esmaeil Ahmadinia, Zargar Majid, Karim Mohamed
Rehan, Mahrez Abdelaziz, Shafig Payam “Using Waste
Plastic bottles as Additive for Stone Mastic Asphalt”
Construction and Building Materials 32 (2011) @
Elsevier Ltd. pp. 4844-4849.
iv.
Esmaeil Ahmadinia, Zargar Majid , Karim Rehan
Mohamed, AbdelazizMahrez, Ahmadinia Ebrahim
“Performance Evaluation of Utilization of Waste
Polyethylene Terephthalate (PET) in Stone Mastic
Asphalt” Construction and Building Materials 36 (2012)
@ Elsevier Ltd. pp. 984–989.
v.
Sabina, Khan Tabrez, A., Sangita, Sharma, D.K.,
Sharma, B.M. “Performance Evaluation of Waste
Plastic/Polymer Modified Bituminous Concrete Mixes”
Journal of Scientific & Industrial Research, (2009), Vol.
68, pp.975-979.
vi.
Modarres Amir and Hamedi Hamidreza “ Effect of Waste
Plastic Bottles on the Stiffness and Fatigue Properties of
Modified Asphalt Mixes” Construction and Building
Materials 61 (2014) @ Elsevier Ltd. pp. 8-15.
vii.
Modarres Amir and Hamedi Hamidereza “ Developing
Laboratory Fatigue and Resilient Modulus Models for
Modified Asphalt Mixes with Waste Plastic Bottles
(PET)” Construction and Building Materials 68 (2014)
@ Elsevier Ltd. pp. 259–267.
viii. MoRTH “Specifications for Roads and Bridge Works”
Ministry of Road Transport and Highway, Government
of India, 5th edition (2013).
ix.
IS: 73-2013, “Paving Bitumen Specification”, (4th
edition) Bureau of Indian Standards, New Delhi, India.
x.
IS: 1202-1978, “Indian Standard Methods for Testing Tar
and Bituminous Material”, Bureau of Indian Standards,
New Delhi, India.
xi.
IS: 1203-1978, “Determination of Penetration”, (1st
edition) Bureau of Indian Standards, New Delhi, India.
xii.
IS: 1205-1978, “Determination of Softening Point”, (1st
edition) Bureau of Indian Standards, New Delhi, India.
xiii. IS: 1206-1978, “Determination of Viscosity”, (1st edition)
Bureau of Indian Standards, New Delhi, India
xiv. IS: 1208-1978, “Determination of Ductility”, (1st edition)
Bureau of Indian Standards, New Delhi, India.
xv.
IS: 2386-1963, “Methods of Test of Aggregates for
Concrete, Part - I, Particle Size and Shape”, (1st edition)
Bureau of Indian Standards, New Delhi, India.
xvi. IS: 2386-1963, “Methods of Test of Aggregates for
Concrete, Part - III, Water Absorption, Los Angles
Abrasion value and Aggregate Impact Value”, (1st
edition) Bureau of Indian Standards, New Delhi, India.
xvii. IS: 2386-1963, “Methods of Test of Aggregates for
Concrete, Part - V, Soundness” (1st edition) Bureau of
Indian Standards, New Delhi, India.
xviii. IS: 6241-1971, “Method of Test for Determination of
Stripping Value of Road Aggregates”, Bureau of Indian
Standards, New Delhi, India.
xix. ASTM: D-1559, “Test for Resistance to Plastic Flow of
Bituminous Mixture Using Marshall Apparatus”.
xx.
AASHTO: T283, “Resistance of Compacted Bituminous
Mixture to Moisture Induced Damage”.
INDIAN HIGHWAYS
OCTOBER 2019
17
TECHNICAL PAPER
SILT FACTOR FOR SCOUR CALCULATION AROUND BRIDGE FOUNDATION
R. K. Dhiman, VSM
Abstract
Foundation of river bridges on alluvial soil is decided based on hydraulic data and subsoil strata. The subsoil strata is
represented by a numerical value called silt factor. This factor plays vital role as the foundation level depends upon soil
strata underneath, which is examined based on the bore log data. Bridges foundations are very costly due to various reasons
depending upon location. There is need to optimize the depth of foundation to a pragmatic level, which can be constructed
without undue delay as per construction practices. Any variation in foundation level at later date plays crucial role in the
overall cost of the bridges and affect the completion time of the project. It is highlighted that pre construction investigation
should be given more attention to avoid any variation in construction programme. Data analyzed based on investigation
need to be reviewed in term of construction trend in the area. The importance of silt factor has been discussed in this paper.
An accurate estimation of the same helps in completing the foundation in time without time and cost overrun. Border Roads
Organisation based on its experience recommend that silt factor upto ‘8’ can be used based on soil strata for calculation of
scour depth for bridge foundation in gravely/bouldery beds.
1. INTRODUCTION
Foundation level for bridges are finalized based on the
hydraulic parameters and the nature of bed material
underneath. The subsoil is rated in term of silt factor,
which is a numerical value. It indicates the type of bed
material from clay to heavy sand. Gravel and Soil Mixed
with Boulder (SMB) falls beyond this range. Foundation
level is fixed below the scour level after considering
the grip length. The scour depth is determined by using
IRC-78 which incorporates the silt factor or on the basis
of results of model study wherever carried out. In bridges
the hydraulic parameters such as the discharge, velocity
need to be estimated accurately as it has direct bearing on
the depth of scour. This has financial bearing and affects
overall completion of bridge. Stress has been laid in this
paper to highlight the importance of scour and silt factor
used for calculation of scour.
2.
SCOUR AND OVERVIEW
The design and construction of foundation of bridges is
linked with the realistic assessment of scour depth, both
global and local. The foundations are generally designed
to withstand the loads and moments transmitted by other
components of the bridge. They are also designed to have a
minimum grip length below the deepest scour level, which
is usually calculated based on various parameters. The best
way of assessing the depth of scour in a river is to observe
1
the same during the highest flood period. Unfortunately
with the methods available it has not been possible to
approach the intended pier location during high floods and
observe deepest scour. Thus the Design Engineer generally
relies on the use of formulae for calculation of scour depth.
While the various available formulae have been known to
give reasonable results in respect of sandy strata, the results
have been erratic in other cases. Various formulae have been
originally evolved based on the study and observations
of particular type of strata, soil classification and water
flow regime. Over the years there has been an increasing
tendency to apply the same formulae for other types of
harder strata’s including conglomerates, large boulders
and soft rock. This has resulted in skewing of results and
arriving at totally unrealistic scour value in extreme cases.
While fortunately in India there has not been many cases
of failure of foundations due to scour, a large number of
bridges are required to have their foundations taken deeper
than necessary depth due to the above referred approach.
Because of this, the time overruns in many cases have been
more than double with corresponding cost overruns. In a
number of well foundations, steinings have been damaged
due to extensive blasting during well sinking necessitating
extensive repairs. In a few cases the wells had to be rejected
because of extensive damages. The situation is acute while
dealing with conglomerate strata, particularly encountered
in the rivers flowing through the foothills of Himalayas.
Chief Engineer, Border Road Organisation, Project Brahmank, E-mail: rkdhiman1964@gmail.com
18
INDIAN HIGHWAYS
OCTOBER 2019
TECHNICAL PAPER
The substrata may consist of boulders, shingle, gravel etc.
either in loose form or cemented by a matrix, which may
be calcareous in nature. Such heterogeneous combination
of material with individual particle size upto two or three
metres does not easily lead itself to any logical assessment
or interpretation of scour using available tools. Substantial
reliance needs to be placed on observation of behavior of
structures built in the past coupled with reasoned judgement
of the decision makers in each individual case. Similar
situations may also arise in other parts. Conglomerate
strata are known to have been encountered in the plains
in various locations leading to dilemma in the matter of
proper assessment of scour. At the outfall end of the river,
the tidal effect needs to be considered. Here fine suspended
sediment deposits are common. The deposition process as
well as scour if any is also affected by changes in the density
of water due to salinity. If these aspects are not considered,
scour depth is generally assessed on conservative basis,
resulting in wasteful design. In such cases, the assessment
of scour needs entirely different perspective. The South
Indian peninsula is geologically more stable. The bed and
banks of the river are generally highly resistant to erosion.
The tendency for a gradation or degradation is insignificant
with such a diverse scenario considering the characteristics
of rivers flowing through the different parts of the country,
it is no wonder that diverse problems are being faced by
the Engineers.
3.
SILT FACTOR
Silt factor plays an important role in determining the scour
depth and also the founding levels for the foundation of
the bridges. Due to lack of adequate bore hole data and
also various uncertainties associated therewith, bridge
engineers are confronted with a difficult job of choosing an
appropriate value of silt factor. This assumes importance
because the present code used for design of bridge
foundation guidelines caters for a maximum factor of upto
2.42, which is applicable for heavy sand only. (Table 1)
Table 1 Silt Factor of Various Sizes of River Bed Material
S.N.
Type of bed material
Mean Size of particle: dm in mm Silt factor – f = 1.76 x √dm
1 SILT
Very fine
0.081
0.520
(less than 75µ) Fine
0.120
0.600
Medium
0.233
0.850
Standard
0.323
1.000
2 Sand
Fine (75 to 425µ)
0.323
1.000
Medium (425U to 2.0 mm)
0.725
1.500
Coarse (2.0 m to 4.75 mm)
1.290
2.000
3 Gravel
Fine (4.75 mm to 20 mm)
5.160
4.000
Coarse (20 m to 80 mm)
26.000
9.000
Since the silt factor has a significant role to play in finalizing
foundation depths, it suffices to say that identification of
correct silt factor poses a problem wherein the selection of
this important parameter is left to the judgment, discretion
and experience of the designer. For calculation of silt
factor in any type of soil, the soil strata is examined in
greater depth and values are calculated in Table 2 & 3. A
worked out example of silt factor is given below:-
Table-2 Sample-1
Dia. of sieve Weight retained gms Percentage retained
2.360
1.180
0.600
0.425
0.300
0.150
0.075
Pan
293
313
172
109
39
59
9
6
1000
29.30
31.30
17.20
10.90
3.90
5.90
0.90
0.60
100.00
Average size of
sieve
1.7700
0.8900
0.5125
0.3625
0.2250
0.1125
-
Col (3) x (4)
55.401
15.308
5.586
1.413
1.327
0.101
79.136
INDIAN HIGHWAYS
(Mean diameter
Col-5 mtr 100
79.136/100=0.7913
K=1.76 m=1.5656
OCTOBER 2019
19
TECHNICAL PAPER
Table-3 Sample-2
1
2.360
1.180
0.600
0.425
0.300
0.150
0.075
Pan
2
49
190
295
253
83
104
20
6
1000
3
4.90
19.00
29.50
25.30
8.30
10.40
2.00
0.60
100.00
4
1.7700
0.8900
0.5125
0.3625
0.2250
0.1125
-
Silt factor = 1.5656 + 1.5587 / 2 =1.5622
The Sample calculation of mean diameter of silt is based
on mathematical expression of averaging.
3.1 Role of silt factor in estimation of scour
The scour depth is calculated based on following
formula.
Db
Ksf
Dsm
Design discharge per meter width
=
Silt factor for representative sample of bed
=
material
=
Mean scour depth
This formula is applicable upto heavy sand only. For
material having heterogeneous stratification in the river
where material is comprises soil mixed with boulder, are
compared with actual observation at site or from experience
on similar structure nearby and their performance. Model
study is also carried out for bridges on requirement and
scour depth is finalized accordingly. Trend of normal scour
calculation with a fixed discharge of 50 cubic mtr per sec
with a different value of silt factor using the IRC fourmula
has been shown in Table 4.
5
33.630
26.255
12.966
3.008
2.340
0.225
78.424
2.42
3.00
4.00
5.00
9.00
13.00
17.00
19.00
20.00
6
78.424/100=0.7842
K=1.76 m=1.5587
13.54
12.60
11.45
10.635
8.74
7.73
7.073
6.82
6.70
Soil strata is gravely
Soil mixed with boulders
3.2Foundation in Gravely / Bouldery Beds
Importance of silt factor for scour calculation can be
further represented in graphical from as indicated below
here it is seen that after a value of silt factor of 8 the value
of mean scour is not changing much and likely to almost
constants for a higher value of discharge.
Table - 4
Silt Factor
0.50
0.60
0.85
1.00
1.25
1.50
1.75
2.00
2.25
20
Dsm
22.91
21.56
19.19
18.18
16.24
15.88
15.09
14.43
13.87
Fine sand to fine gravel
INDIAN HIGHWAYS
Fig. 1 Silt Factor for Scour calculation
Most of bridges gravely/bouldery beds whether
already completed or under construction have faced
foundation problems especially in sinking of wells of
multi span bridges. Whenever problems of sinking of
well are faced, case is examined with reference to soil
strata actually encountered. The task of subsequent
review of foundation levels based on actual strata
OCTOBER 2019
TECHNICAL PAPER
encountered (review of silt factor) need reprocessing
of case. Data of silt factor actually used for few
bridges with gravely to bouldery soil strata in Border
Road Organisation is given in Table 5.
Table-5 Silt Factor Taken and Actual Strata on Ground
Pasighat (AP)
24
8
Well
Span
(m)
Strata available on
ground
762
Large size of
boulders available at
foundation level and
in river beds.
Photographs
Pneumatic sinking
was done at this
bridge.
2.
Siku (AP)
1.25
5.572
Well
480
Large size boulders
and khadir width
is about 1.2 Kms.
Bridge is located at
one side of channel
as two river joins on
U/stream.
3.
Sissri (AP)
9.88
6.18
Well
135
Bridge is located on
bouldery beds. Both
side high bank.
4.
Bakcha-chu 7.22
(S)
7.50
Well
120
Large size boulders
in beds. Both bank
has high vegetation.
5.
Toong Bridge 1.26
(S)
21.93
Well
130
River bed is bouldery
and straight reach.
6.
Sibokor-ang 10.40
(AP)
3.34
Open
110
River straight
channel and has
tendency to outflank.
INDIAN HIGHWAYS
OCTOBER 2019
Remarks
This is due to less erosion of bed due to large sized of material laying in river bed
1.
V
Type of
(m/sec) founda-tion
2.
Ksf
Scour has been recorded less than 15% of the designed value in all the bridges. (Srl no 1 to 6).
Name of
Bridge
1.
S.No.
21
B h a g i r a t h 1.50
(UA)
9.87
Open
110
Bouldery bed river
8.
Dalai (AP)
9
8.83
Well
130
Soil strata at
foundation level is
compacted very near
to rock.
9.
Lohit (AP)
5.05
9.00
Well
410
Pneumatic sinking
was used due to
difficulty in sinking.
Rock encountered at
foundation level.
10. Diffo (AP)
7.72
5.78
Well
426
Bouldery beds and
channel straight and
flat.
11. S h i m o n g 8.00
(AP)
3.40
Well
140
Compacted bouldery
strata
12. Sime Korang 2.00
(AP)
8.79
Well
140
Bouldery beds
and bank are loose
soil mixed with
boulders.
13. Dundi (H.P)
6.20
Open
160
Large size of
boulders. Bridge
located at
downstream of
confluence point.
22
6.792
INDIAN HIGHWAYS
OCTOBER 2019
2. This is due to less erosion of bed due to large sized of material laying in river bed
7.
1. Scour has been recorded less than 15% of the designed value in all the bridges. (Srl no 7 to 13).
TECHNICAL PAPER
TECHNICAL PAPER
There are bridges as indicated in above table the value
of silt factor is not matching with the grade of material.
Hence deeper depth was planned which was not possible
to achieve. This need better examination for all bridges
under planning.
c.
d.
As per IRC formula given in code not applicable to
bouldery/gravely soil but same has been extended to soil
mixed with boulders.
e.
There are certain important points which require
attention of bridge engineer for better planning of bridge
foundation.
a.
Correct finalization of silt factor at initial stage will
be helpful to optimize cost of the bridge. The will
also be helpful to adhere to original time schedule
as the there is no likely mismatch of strata.
f.
4.
Fig: 2 Comparison between scour hole in sandy and
bouldery beds
b.
Cost of sinking of foundation can be adhered if there
Fig.-3
is no variation in soil parameter including silt factor.
Foundation depth is required to be finalized as
per the construction technology available in the
country.
Infact there is need to take a stock of situation
about the construction methodology, in such a way
that the proposal finalized should be executable on
the ground.
The completion of the particular project and related
difficulties encountered be examined with reference
to silt factor, as this is the only one major factors
affecting the design scour. There are other factors
affecting scour around bridge pier viz. Whether
the flow is clear water flow or carries sediments,
change in depth of flow, shape of pier nose, angle of
inclination of pier, opening ratio, bed characteristics,
stratification and effect of flow parameters.
Based on the above information and experience
‘BRO’ firmly believe that silt factor value upto
‘8’ can be considered with present formula as per
IRC:78 for calculation of scour in gravely / boulder
beds. This has also been explained in paper No.508
published in IRC Journal in 2004 as “Bouldery Bed
Scour-Proposed formula”.
RECOMMENDATIONS
There are number of bridges where completion got delayed
and in a few cases bridge could not be completed to due
difficulties in construction of foundation. This may be due
to incorrect assessment silt factor and design of foundation
or other construction difficulties. Few locations are as
under (Fig 3 & 4)
Fig.4
Fig: 3 & 4 Bridge foundation could not be completed at proposed location of bridges in J&K due to non
matching of strata
INDIAN HIGHWAYS
OCTOBER 2019
23
TECHNICAL PAPER
factor can be further reviewed if it does not match
with the calculation as finalized initially during
sub soil investigation state. Maximum value upto
‘8’ can be considered for finalisation of scour
depth in gravely/bouldery beds. This has been
applied in no of Bridges constructed by BRO as
shown in Table 6.
Various steps to be followed to arrive at correct value of
silt factor are as follows:a. Keep a drilling record of the entire bore log and
assess the value of silt factor upto foundation level
at initial stage.
b. During construction of foundation better picture
of soil strata can be seen and accordingly the silt
Table 6.
c.
d.
5.
Value of different silt factor value can be calculated
for 2 to 3 of bore log details and average value can
be adopted.
Wherever that silt factor value is not assessable,
the soil strata actually
encountered
during
execution is reviewed and practical aspect is kept
in view and
final value is arrived at.
i.
ii.
iii.
CONCLUSION
Silt factor plays an important role in finalization of
foundation levels. In case of difficulties faced in finalizing
level of foundation based on silt factor, model study can
also be reviewed if carried initially otherwise, experienced
gained at previous bridges can be dove-tailed for future
bridges for finalizing their foundation level. Efforts should
be made to assess correct value of silt factor to optimize
the depth of foundation and there will be no time and cost
overrun. However in case of gravely/bouldery soil the
value of silt factor upto ‘8’ can be considered as done in
Border Roads Organisation in various bridges constructed
in hilly areas.
24
REFERENCES
INDIAN HIGHWAYS
OCTOBER 2019
iv.
v.
vi.
vii.
viii.
Dhiman RK “Effective Construction Management
for Bridges” Dec-1996 International Association of
Bridges and Structural Engineers (IABSE).
Dhiman RK “Pneumatic Sinking–A Case Study” Indian
Highways Feb 1996 Indian Roads Congress (IRC).
Dhiman RK “Caisson launching A–Case Study–
1006” Civil Engineering and Construction Review
(CE&CR).
Dhiman RK – Essence of Soil Factor Bridge Foundation
– IGS Conference Baroda – 1997.
Dhiman RK “Construction Problem of Bridges in Hilly
Region–A Review–1997” International Association of
Bridges and Structural Engineers (IABSE)
Dhiman RK “DIMWE Bridge Foundation–A Case
Study” 4th International Seminar on Bridge and
Aquetunnel - 1998
Dhiman RK “Well Foundation Construction in Bouldery
Bed–A Case Study–1999” International Association of
Bridges and Structural Engineers (IABSE).
Dhiman RK “Bouldery bed Scour –Proposed Formula”
IRC Journal 65 Vol-3 Paper No. 508
TECHNICAL PAPER
Performance Analysis of PLAXIS Models of Stone Columns in
Soft Marine Clay
M.Vinoth1
P.S. Prasad2
U.K. Guru Vittal3
Abstract
The behaviour of stone columns in soft marine clay under a cement concrete road pavement was examined through
PLAXIS 2D. It is a well-known fact that modeling in 2D will require less computational effort compared to a full 3D
analysis. Main difficulty with regard to PLAXIS 2D modeling of stone columns is conversion of the stone column grid to
a 2D stone trench structure. Different approaches (Enhanced Soil Parameter, Embedded Beam Element and Equivalent
Column Method) are available in modeling of stone column in PLAXIS 2D. However, not much literature is available
for choosing the proper approach in PLAXIS 2D modeling of stone column in soft marine clay. The aim of this paper is
to establish the suitable approach which provides better results with minimal effort for modeling in PLAXIS 2D. A case
study, of work carried out at Mumbai for the road pavement between Wadala Depot and Chembur provide the basis for
PLAXIS 2D modeling. The sub-soil profile in this stretch comprises of soft marine clay and the ground below cement
concrete pavement had been treated with stone column prior to construction of rigid pavement. The results of the PLAXIS
2D models were then validated by examining the main characteristics of cement concrete pavement deformation within
the column grid.
1.
Introduction
Installation of stone-columns in soft marine clay are
very common as it increases the load carrying capacity
of the foundation soil as well as provides the free
drainage path for water to travel to the ground surface
and reduces the post-construction settlements. In order
to assess stone column performance through numerical
modeling, designer has to go through one of the complex
task, which is the conversion of the stone column grid to
a two-dimensional (2D) stone trench structure. Earlier
researchers have proposed several methods to convert
the axisymmetric unit cell to the equivalent plane-strain
model for the purpose of 2D numerical modeling of multi
drain field applications Hird et al. 1992; Indraratna and
Redana 1997. These conversion methods involved the
derivations of the equivalent plane-strain permeability
or the equivalent plane-strain geometry based on the
matching of axisymmetric and plane-strain consolidation
analytical solutions. Numerical modeling by using finite
Scientist, Email: vinothm.27@gmail.com
Principal Scientist, Email: pulikanti@gmail.com
3
Head & Chief Scientist, Email: vittal.crri@gmail.com
element software PLAXIS 2D 2015 provides three
different approaches (Enhanced Soil Parameter (ESP),
Embedded Beam Element (EBE) and Equivalent Column
Method (ECM)) for modeling stone column. Each one
of these approaches has been separately used by various
researchers Tan (2008); Ng (2014) for modeling stone
column but a comparative study to bring out the best
suited method for this type of problems are not addresses.
So, in the present study, a comparative performance of
these three approaches, by comparison with the field
data from a case history carried out at Mumbai for the
road pavement between Wadala Depot and Chembur.
The finite column permeability and smear effects are
excluded in this study.
2.
Case History Details
The soil profile considered for the present study is from
the case history of Mumbai monorail project, Mumbai
Prasad et al. (2016). The width of the six lane concrete
road is 11m. The surcharge loading considered for
1
2
CSIR – Central Road Research Institute, CRRI, New Delhi
INDIAN HIGHWAYS
OCTOBER 2019
25
TECHNICAL PAPER
the analysis is 44kN/m2 (including the dead load of
pavements). Typical soil profile in this stretch is given
in Table 1.
Table-1 Typical Soil Profile
Type of soil
Layer Thickness
SPT 'N' Value
Fill Soil
0.5 to 4.5
5 to 8
Soft Clay
0.5 to 12
3 to 6
Stiff Clay
7.5 to 16.5
5 to 45
CWR
13.5 to 16.5
>50
MWR
>10
>100
a) Axisymmetric b) Plane Strain
Fig. 1: Cross Sections of Unit-Cell Stone Column and
Plane-Strain Conversions
CWR – Completely Weathered Rock
MWR – Moderately Weathered Rock
The ground water level in the boreholes varied from 1.1 m
to 1.7 m from Natural Ground Level (NGL). The stone
columns are arranged in triangular pattern. The diameter
and spacing of stone columns are 0.9 m and 2.5 m c/c
respectively. Depth of stone column from ground surface
varies from 9 m to 12 m. Six borehole data (BH-01, BH02, BH-03, BH-04, BH-05 and BH-06) were considered
for the comparative study.
3.Formulation
of
Equivalent
Stiffness and Permeability
For ECM and EBE the equivalent stiffness was arrived
based on the approach proposed by Tan and Oo (2005)
and for ESP H.J. Priebe (1995) approach was followed.
Permeability for all the three cases were arrived based
on the approach suggested by Tan and Oo (2005).These
approaches are reviewed here.
As per Tan and Oo (2005) approach, equal flow path
length normal to the column perimeter can be obtained by
considering the column width of plane-strain case equal to
the axisymmetric column diameter, i.e.
bc = rc (1)
as shown in Figs. 1a and 1b. Similarly Indraratna and
Redana (2000) used this type of geometrical transformation
in their permeability matching approach for the planestrain conversion of vertical drains. So, the equivalent
plane-strain width B can be taken equal to the radius of
drainage zone R [Figs. 1a and 1b], i.e.
(2)
R=B
In general, this geometry conversion method is a very
easy one since the transition between plane-strain meshed
geometry and axisymmetric can be derived from the same
basic (2D) input geometry.
26
INDIAN HIGHWAYS
OCTOBER 2019
Accordingly, material properties of plane-strain also need
to be adjusted to account for the geometrical changes. By
matching the column-soil composite stiffness, following
relationship can be used to arrive at the plane-strain
material stiffness
(3)
where, Ecomposite and Es=elastic moduli of the composite
material and the surrounding soil, respectively, and
subscript ax denote axisymmetric conditions. Area
replacement ratio as=Ac/(Ac+As), where Ac and As=crosssection areas of the column and the surrounding soil
respectively. The composite stiffness obtained from Eq.
(3) gives the average stiffness of the axisymmetric unit
cell. The relevant stiffness of the stone column and the
surrounding soil of the plane strain model are computed
by using the composite stiffness of the axisymmetric
unit cell (Ecomposite) obtained from Eq. (3).The relation for
computation of stiffness of materials in the plane strain
unit cell is given by:
(4)
For simplicity, Es,pl=Es,ax, has been considered in this
study. Hence Ec,pl can be determined from Eq. (4). The soil
permeability was matched by using the following equation
as derived by Tan and Oo (2005):
(5)
where, kh=coefficient of soil permeability in horizontal
direction; αvc and αvs=coefficients of compressibility
of the column and the surrounding soil, respectively.
; diameter ratio N=R/rc
for axisymmetric condition, whereas N=B/bc for planestrain condition; mvs=αvs/(1+es); mvc=αvc/(1+ec); and ec
and es=void ratios of the columns and the surrounding
soil, respectively. As, the influence of soil permeability
in vertical direction kv,pl is negligible when compared to
horizontal it is assumed that plane strain vertical flow to
be same as axisymmetric condition, kv,pl=kv,ax.
TECHNICAL PAPER
H.J. Priebe (1995) proposed improvement factors for
soil improved through installation of stone columns.
Improvement factors are evaluated on the assumption that
the column material shears from the beginning while the
surrounding soil reacts elastically. Furthermore, the soil
is assumed to be displaced already during the column
installation to such an extent that its initial resistance
corresponds to the liquid state: i.e. the coefficient of earth
pressure amounts to K=1.The result of the evaluation is
expressed as basic improvement factor n0.
(6)
where,
; µ= Poisson’s
ratio;
; A= area of unit cell, Ac=
cross sectional area of single stone column. The columns
materials are still compressible. This compressibility of
the stone column material can be addressed by using a
reduced improvement factor n0. This can be arrived from
the formula developed for the basic improvement factor n,
when the given reciprocal area ratio A/Ac is increased by
an additional amount of Δ(A/Ac).
(7)
The stone columns are better supported laterally with
increasing overburden and, therefore, can provide more
bearing capacity. Therefore, in-order to consider this effect
depth factor fd is calculated based on following equation
and suitably applied to the improvement factor,
(8)
; p = surcharge pressure,
d = thickness of soil layer, γs and γc bulk density of
soil and column. In order to counter simplifications
and approximations, compatibility controls have to be
performed. This is to guarantee that the settlement of the
stone columns resulting from their inherent compressibility
does not exceed the settlement of the surrounding soil
resulting from its compressibility by the loads which
are assigned to each. So using the following equation
improvement upper limit of improvement factor can be
obtained,
(9)
where, Dc and Ds are the young’s modulus of stone column
and soil respectively. Final improvement factor is given
by,
n2=fd×n1
(10)
Therefore, enhanced stiffness of soil will be equal to
existing soil stiffness multiplied by improvement factor n2.
Similarly shear resistance from friction of the composite
system can be calculated using the below equations,
(11)
(12)
where,
; n = improvement factor, φc
and φs are angle of internal friction of column and soil
respectively, c’= Cohesion of unimproved soil.
4.
Settlement Calculation
Theoretical settlement was calculated by using Terzahgi’s
(1995) one dimensional consolidation equation.
(13)
where, Cci = Compression Index of respective layer, Hoi
= Thickness of respective layer, e0i = Initial void ratio
of respective layer, σv'fi = final vertical effective stress of
respective layer, σv’oi = Initial vertical effective stress of
respective layer.
As per the reduced stress method, settlement reduction
factor due to stone column installation was determined
using the following equation,
(14)
where, n = σs/σg; σs and σg are vertical stress in compacted
columns and surrounding ground.
5.
Numerical Modeling
Three different finite-element models of the stone column
improved soil section were considered: Enhanced Soil
Property, Equivalent Beam Method and Equivalent
Column Method. The plane-strain modeling was chosen
as the road spanned a distance of about 8.5km with almost
uniform cross-sectional geometry in the direction normal
to the plane. The plane-strain models were developed
using 15-node triangular elements in PLAXIS 2D version
2015. For EBM and ECM, the width of stone columns was
considered as 0.9 m, same that of axisymmetric condition.
A spacing of 2.5 m was uniformly considered in all the
embankment models. Self-soil weight was taken into
account by applying the gravity effect, assuming the default
gravity acceleration, g, is 9.810 m/s2, and the direction is
with the negative y-axis. Default unit weight of the water
is 10 kg/m3. In order to minimize the boundary effects,
the overall geometry of the model was kept more than 5
INDIAN HIGHWAYS
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27
TECHNICAL PAPER
times and 2.5 times the width of road in X-direction and
Y-direction respectively. During mesh generation stage,
fine refinement was used so that more number of elements
will be generated for obtaining more precise results. In
order to simulate the dead load (self weight of pavement
layers) and live load at top a line load with an intensity of
44kPa was applied. Parameters used for the analysis of
BH-01 borehole data is listed in Table 2; where, γ=bulk
density; φ’=angle of internal friction; c’=cohesion;
E=young’s modulus or stiffness; µ=Poisson’s ratio; kh and
kv are coefficient of permeability in vertical and horizontal
direction respectively.
Table - 2 Material properties of all models - BH-01
Material
Model
Drain Type
γ (kN/m3) γsat (kN/m3) Φ’ (°) C’ (kPa)
E (kPa)
µ
kv (m/day)
kh (m/day)
Fill Soil#
HSM
Drained
18
18.75
29
0.1
11500
0.3
8.64
8.640
Soft Clay*
SSM Undrained (A)
15.6
15.6
1
13.5
3100
0.4
0.069
0.165
Stiff Clay**
SSM Undrained (A)
16.6
16.6
1
22.5
6000
0.4
0.102
0.177
MWR
HSM Undrained (B)
19.5
20.5
33
3500
1.43E+07 0.25
0.1
0.033
Stone Column
MC
Drained
19
20
42
0.1
12200 0.33
1
1.000
Embedded Beam
19
Layer Dependent
12200
Layer Dependent
# Values are only for ECM and EBM; corresponding for ESP model, E = 21487kPa.
*Values are only for ECM and EBM; corresponding for ESP model, E = 6107kPa and 8106 for above water table and below water
table respectively.
** Values are only for ECM and EBM; corresponding for ESP model, E = 15134kPa.
HSM – Hardening Soil Model; SSM – Soft Soil Model; MC – Mohr Coulomb
The soft soils were modeled as undrained material
in PLAXIS. Stone column for ECM was idealized
as a homogeneous drained material having certain
characteristics of stiffness and strength parameters. The
elastic modulus of column material was taken as ten times
of that of soil. The compression index cc, swell index cs
and initial void ration e0 of soft clay is 0.59, 0.144 and
1.973 respectively. The compression index cc, swell index
cs and initial void ration e0 of stiff clay is 0.38, 0.125 and
1.438 respectively. Permeability in horizontal direction for
soft clay is taken as twice of vertical direction. In order to
avoid numerical complications, a small nonzero value has
been considered for the strength parameters.
Plane strain model parameters considered for both ECM
and EBM are same, stiffness for both the method was
determined using Eq. (3 & 4). Permeability for all the three
methods for modeling in PLAXIS 2D 2015 was arrived
from Eq. (5). Shear parameters and stiffness values for
embedded beam was selected as layer dependent. Stiffness
parameters for ESP method Eq. (6 to 10) was used and
shear parameter using Eq. (11 & 12).
5.1 Simulation Procedures
The project involved installation of stone columns and
construction of six lane concrete road over it was simulated
as follows. The stone columns were first installed by
partial soil replacement for ESP and ECM but for EBM
embedded beam row is activated. Next stage surcharge
load (including the dead load of pavements) is activated.
28
INDIAN HIGHWAYS
OCTOBER 2019
Last stage consolidation process is carried out till the
excess pore water pressure reduces to 1kPa, once this
value is reached analysis stops.
6.
Results and Discussions
Analysis for all the six boreholes was done using all
the three methods (i.e. ESP, EMB and ECM). Typical
maximum settlement obtained from the analysis carried
out using BH-01 has been shown in Figs. 2a, 2b and 2c.
Theoretical settlements were calculated using Eqs. (13 &
14). All the analysis results along with theoretical and field
values [obtained through leveling by Mumbai Mono Rail
Development Authority in October 2010 and February
2015. This level difference as reported varies from 250 to
550 mm at different chainages, Prasad et al. (2016)] are
tabulated in Table 3.
From Table 3, it can be seen that out of three methods
Embedded Beam Method has better results than other two
methods. One of the other interesting things we can notice
is that theoretical predications also vary with field values
in the range of 16% to 56%. This variation is also erratic
because in some cases it has over predicted and in others
under estimated. In cases where theoretical predictions are
on higher end may be because the top fill layers would
have dissipated the surcharge, leading to lower load
intensity transferred to the soft soil layers and resulting
in lesser settlement. Reason for under prediction may be
the fill thickness is less than those consider for settlement
calculation.
TECHNICAL PAPER
Except one bore hole in all the other cases ESP has under
estimated settlement in the range of 40% to 90%. EBM
except last borehole location in all other location it has
predicted settlement with just 25% variation. In ECM,
constantly in all locations it has under estimated the
settlement in the range of 50% to 90%.
It can be noted that for BH-05 and BH-06 all the methods
including theoretical approach has under estimated the
settlement. So this shows that actual thickness of fill and
soft soil varies at site than what is considered for the study.
Fig. 2a Displacement - ESP
Table - 3 Settlement Comparison
Borehole
Theoretical
BH-01
BH-02
BH-03
BH-04
BH-05
BH-06
455.6
349.0
317.6
390.9
289.4
258.1
ESP
615.2
147.1
137.1
181.2
166.1
39.55
PLAXIS
EBM
400.6
209.3
222.2
226.1
233.7
103.6
ECM
160.3
100.8
124.1
76.52
106.8
41.22
Field
(*)
325
300
250
300
450
450
(*)Prasad et al. (2016)
In order to explain the huge variation of settlement prediction
among the three methods, each models material stress state at
the end of the analysis was studied. Figs. 3a to 3c and Figs. 4a
to 4c shows the elastic points and plastic points respectively at
the end of simulation. It can be seen that EBM has very little
elastic points and some plastic yielding in the surrounding
region of the column material. It is clearly indicated by
numerous plastic stress points that are concentrated within
and slightly beyond the column periphery. The yielding
pattern of the other two methods are almost same but with
less scatter beyond the column periphery and more plastic
points, this explains the differential responses of the other
two methods. The plastic yielding in the EBM allows itself to
simulate the settlements of actual field case, while the other
model’s elasticity gives a stiffer response leading to a lower
final settlement. The sustained elastic behavior in the ECM
and ESP may be due to its larger cross-sectional column area
with higher elastic capacity in both shearing and bending.
Fig. 2b Displacement - EBM
Fig. 3a Elastic Points - ESP
Fig. 2c Displacement – ECM
Fig. 3b Elastic Points - EBM
INDIAN HIGHWAYS
OCTOBER 2019
29
TECHNICAL PAPER
Fig. 3c Elastic Points - ECM
Fig. 4a Plastic Points - ESP
Fig. 4b Plastic Points - EBM
Fig. 4c Plastic Points - ECM
7.
Conclusion
This paper presents a comparative performance study of three
different approaches (i.e. Enhanced Soil Parameter, Embedded
Beam Element and Equivalent Column Method) available
in PLAXIS 2D 2015 version for assessing the settlement
performance of stone column, by comparison with the field
data, from a case history carried out at Mumbai for the road
pavement between Wadala Depot and Chembur. Six borehole
data were considered for the comparative study.
Stiffness and permeability of axisymmetric condition
was converted into equivalent plane strain values using
30
INDIAN HIGHWAYS
OCTOBER 2019
Tan and Oo (2005) approach. Enhanced shear parameters
of soil was also determined using H.J. Priebe (1995)
approach. Theoretical settlement was calculated using
Terzahgi’s (1995) one dimensional consolidation equation
and settlement reduction factor due to stone column
installation was determined using reduced stress method.
With all these data, analysis was carried out in PLAXIS
2D 2015. Following points can be brought out from the
analysis results,
i.
Out of three methods Embedded Beam Method has
better results than other two methods. Except the last
borehole location in all other location it has predicted
settlement with just 25% variation.
ii. Except one bore hole in all the other cases ESP has under
estimated settlement in the range of 40% to 90%.
iii. ECM constantly in all locations it has under estimated
the settlement in the range of 50% to 90%.
iv. The plastic yielding in the EBM allows itself to
simulate the settlements of actual field case, while
the other model’s elasticity gives a stiffer response
leading to a lower final settlement. The sustained
elastic behavior in the ECM and ESP may be due to its
larger cross-sectional column area with higher elastic
capacity in both shearing and bending.
Thus, Embedded Beam Method is the preferred method for
carrying out numerical modeling for elasto-plastic materials.
REFERENCE
i. Hird, C. C., Pyrah, I. C., and Russell, D. (1992) Finite
Element Modelling of Vertical Drains Beneath Embankments
on Soft Ground, Geotechnique, 42(3), pp. 499–511.
ii. Indraratna, B., and Redana, I. W. (1997) Plane-Strain
Modeling of Smear Effects Associated with Vertical Drains,
J. Geotech. Geoenviron. Eng., 123(5), pp. 474–478.
iii. Indraratna, B., and Redana, I. W. (2000) Numerical Modeling
of Vertical Drains with Smear and Well Resistance Installed
in Soft Clay, Can. Geotech. J., 37(1), pp. 132–145.
iv. Prasad, P.S., Guru Vital, U.K., Sitaramanjaneyulu, k., and
Madhav, M.R., (2016) Remedial Measures for Upheaval
of PQC Panels Adjacent to Piers of Mumbai Monorail in
Mumbai, 5th ICFGE-2016, Bengaluru, India, pp. 366–377.
v. Priebe, H.J. (1995) The Design of Vibro Replacement,
Ground Engineering, December, 1995, pp. 31-37.
vi. Tan, S. A., Tjahyono, S. and Oo, K. K. (2008) Simplified
Plane-Strain Modeling of Stone-Column Reinforced
Ground, Journal of Geotechnical and Geo-environmental
Engineering, ASCE, February 2008, 134(2): pp. 185–194.
vii. Tan, S. A., and Ng, K. S. (2014) Simplified Homogenization
Method in Stone Column Designs, The Japanese
Geotechnical Society, Soils and Foundations2015;55(1):
pp. 154–165.
viii. Terzaghi, K., Peck, R.B., and Mesri, G. (1996) Soil Mechanics
in Engineering Practice, Third Edition, Part II, Theoretical
Soil Mechanics, John Wiley & Sons Inc. New York.
MoRT&H Circular
INDIAN HIGHWAYS
OCTOBER 2019
31
32
INDIAN HIGHWAYS
OCTOBER 2019
Sr. No. 5 of FIG. 6B
4
(Refer amendments
published in Indian
Highways – January 2018
issue)
Sr. No. 4 of FIG. 6B
(Refer amendments
published in Indian
Highways – January 2018
issue)
(Refer amendments
published in Indian
Highways – January
2018 issue)
204.5.4
(Page 20)
204.4
3
2
1
S. Clause No
No Page No
Read
During the passage of SV loading, no other live load (including
footway live load) shall be considered to ply on the same carriageway.
Effect of wind, seismic, temperature gradient need not be considered
for load combinations with SV loading. In addition, tractive force
/ braking force and dynamic impact on live load need not be
considered on the carriageway carrying SV loading. For the load
combination with special vehicle, the partial safety factor on SV load
for verification of equilibrium (as per Table B.1), structural strength
(as per Table B.2) and strength of foundation (as per combination 1
of Table B.4) under Ultimate Limit State (Basic Combination) shall
be taken as 1.15. For verification under Serviceability Limit State
and for other accompanying loads, including the live load surcharge
loading, Table B.3 shall be followed with partial safety factors on
SV load taken as 1.0 under Rare Combination (For stress check)
and 0.75 under Frequent Combination (For deflection and crack
width checks as applicable). Fatigue check is not required under
Load Combination with SV loading.
Add a sentence in 2nd column under “No. of Lanes and Carriageway Add following at the end in next para :
configurations”
(Load combinations & partial safety factors as given in clause
204.5.4 shall apply for the entire structure)
Add a sentence in 2nd column under “No. of Lanes and Carriageway Add following at the end in next para :
configurations”
(Load combinations & partial safety factors as given in clause
204.5.4 shall apply for superstructure carrying SV loading and for
substructure and foundation)
Note : The movement of Special Vehicle shall be regulated /
monitored to ensure that it moves at a speed less than 5 Kmph and Note : The movement of Special Vehicle shall be regulated /
monitored to ensure that it moves at a speed less than 5 Kmph and
also does not ply on the bridge on a high wind condition
also does not ply on the bridge on a high wind condition
During the passage of SV loading, no other vehicle shall be
considered to ply on the same carriageway. No wind, seismic,
temperature gradient, braking force and dynamic impact on the live
load need to be considered as the SV shall move at a speed not
exceeding 5 kmph over the bridge. For the load combination with
special vehicle, the partial safety factor on SV load for verification
of equilibrium and structural strength under Ultimate Limit State
(Basic Combination) and for verification of Serviceability Limit
State (Rare Combination) shall be taken as 1.15 and 1.0 respectively.
For other accompanying loads, partial safety factors shall be taken
from Annex-B.
Add a sentence after the first sentence “For bridges, Flyovers/grade Add following sentence after the first sentence “For bridges,
separators close ……shall be considered.”
Flyovers/grade separators close …shall be considered.” :
“Congestion factor shall not be applicable in load combination with
SV loading.”
For
Notification No. 24
Amendment No.5/IRC:6/August, 2019 (Effective from 31st October, 2019)
To
IRC:6-2017 “Standard Specifications and Code of Practice for Road Bridges,
Section-II Loads and Load Combinations” (Seventh Revision)
Notifications
5.
(Page 26-28)
Crash Barriers
206.6
Containment for
15 kN vehicle at 80 km/h
and 20o angle of impact
P-1: Normal
Containment
(Cast-in-situ or
Precast as per
Fig. 1,2 & 5 of
IRC:5-2015)
Category
INDIAN HIGHWAYS
Minimum moment of
15
7.5
resistance at base of the kNm/m kNm/m
wall [see note (i)] for
bending in vertical plane
4)
3)
175
mm
M40
Minimum grade of
M40
concrete
Minimum thickness of R 175
C wall (at top)
mm
2)
P-3
In-situ
100 kNm/m for
end section and
75 kNm/m for
intermediate
section [see note
(iii)]
250 mm
M40
Shape on traffic side to be as per IRC:5,
or New Jersey (NJ) Type of ‘F’ Shape
designated thus by AASHTO
Shape
Requirement
Types of Crash Barrier
P-1
P-2
In-situ/ In-situ/
Precast Precast
1)
S.
No
Table 10: Minimum Design Resistance
metallic cold-rolled and/or hot-rolled sections. The metallic type,
called semi-rigid type, suffers large dynamic deflection of the order
of 0.9 to 1.2 m due to impact, whereas the ‘rigid’ concrete type
suffers comparatively negligible deflection. The efficacy of the
two types of barriers is established on the basis of full-size tests
carried out by the laboratories specializing in such testing. Due to
the complexities of the structural action, the value of impact force
cannot be quantified.
Containment for
At hazardous and high-risk
locations ie, over busy
railway lines, stretches
on curves having radius
less than 100 meters and
complex interchanges, etc
300 kN vehicle at
60 km/h and
20o angle of impact
Bridges carrying
15 kN vehicle at
Expressway, National &
110 km/h and
State Highway or Road of
20o angle of impact
equivalent standard except
over railways and high-risk
locations
Application
For the rigid type of barrier, the same method is acceptable. However,
in absence of testing/test certificate, the barrier shall be designed to
resist loading appropriate to the designated level of containment
using the equivalent static nominal loadings from Table 10.
The crash barriers can be of rigid type, using cast-in-situ/precast
reinforced concrete panels, or of flexible type, constructed using
metallic cold-rolled and/or hot-rolled sections. The metallic type,
called semi-rigid type, suffers large dynamic deflection of the order
of 0.9 to 1.2 m due to impact, whereas the ‘rigid’ concrete type
suffers comparatively negligible deflection. The efficacy of the two
types of barriers is established on the basis of full-size tests carried
out by the laboratories specializing in such testing. A certificate from
such laboratory can be the only basis of acceptance of the semi-rigid
type, in which case all the design details and construction details
tested by the laboratory are to be followed without modifications
and without changing relative strengths and positions of any of the
connections and elements.
P-2: High
Containment
(Cast-in-situ
The barriers can be of rigid type, using cast-in-situ/precast as per Fig. 3 of
reinforced concrete panels, or of flexible type, constructed using IRC:5-2015)
P-3: High
At hazardous and high risk
300 kN vehicle at 60 km/h
and 20o angle of impact
Containment locations, over busy railway
lines, complex interchanges, etc.
P-2: Low
All other bridges except
Containment bridge over railways
P-1: Normal Bridges carrying expressway, 15 kN vehicle at 110 km/h,
Containment or equivalent
and 20o angle of impact
Application
Table 9: Application for design of Crash Barrier
Table 9: Application for design of Crash Barrier
Category
Crash barriers are designed to withstand the impact of vehicles of
certain weights at certain angle while travelling at the specified
speed as given in Table 9. They are expected to guide the vehicle
back on the road while keeping the level of damage to vehicle as
well as to the barriers within acceptable limits.
Crash barriers are designed to withstand the impact of vehicles of
certain weights at certain angle while travelling at the specified
speed as given in Table 9. They are expected to guide the vehicle
back on the road while keeping the level of damage to vehicle as
well as to the barriers within acceptable limits.
Notifications
OCTOBER 2019
33
34
6.
P-3
In-situ
INDIAN HIGHWAYS
OCTOBER 2019
Minimum
8)
900 mm 900 mm 1550 mm
(Page 90)
For checking the equilibrium of the structure, the partial safety factor for loads
shown in Column No. 6 or 7 under Table B.1 and for checking the structural
strength, the partial safety factor for loads shown in Column No. 4 under Table
B.2 shall be adopted.
Sr No. 6
Seismic Combination
6.
Annex B
i)The base of wall refers to horizontal sections of the parapet within 300
mm above the adjoining paved surface level. The minimum moments of
resistance shall reduce linearly from the base of wall value to zero at top
of the parapet.
ii)In addition to the main reinforcement, in items 4 & 5 above, distribution
steel equal to 50 percent of the main reinforcement shall be provided in
the respective faces.
iii)For design purpose the crash barrier Type P-3 shall be divided into end
sections extending a distance not greater than 3.0 m from ends of the
crash barrier and intermediate sections extending along remainder of the
crash barrier.
iv)If concrete barrier is used as a median divider, the steel is required to be
placed on both sides.
v)In case of P-3 In-situ type, a minimum horizontal transverse shear
resistance of 135 kN/m shall be provided.
Notes :
Minimum transverse shear
44
22.5
Not applicable
resistance at vertical joints
kN/m
kN/m
between precast panels, or at of joint of joint
vertical joints made between
lengths of in-situ crash barrier.
7)
22.5
11.25
Not applicable
kNm/m kNm/m
Minimum moment of
resistance of anchorage at the
base of a precast reinforced
concrete panel
6.
7.5
3.75
40 kNm/m
kNm/m kNm/m
P-1
P-2
In-situ/ In-situ/
Precast Precast
Minimum moment of
resistance for bending
in horizontal plane with
reinforcement adjacent to
outer face [see note (ii)]
Requirement
5)
S.
No
Types of Crash Barrier
(210+40 L) kN/panel
High Containment
without shear transfer
between panels
Seismic Combination
For checking the equilibrium of the structure, the partial safety factor for loads
shown in Column No. 6 or 7 under Table B.1 and for checking the structural
strength, the partial safety factors for loads shown for seismic combination
under column 4 of Table B.2 and B.4 are applicable only for design basis
earthquake (DBE) .
6.
i)Panel Length (L) for cast-in-situ and precast barrier shall be 2.0 m
minimum.
ii) Panel Length (L) for cast-in-situ barrier shall not exceed 3.5 m.
iii)H=Vertical distance in meters from top of barrier to the horizontal
section where shear force is considered.
iv)Gaps between panels shall be 20 mm. Gaps shall be covered or sealed
and filled with a durable soft joint filler.
v)*The bending moment to be resisted produced by applying
transversely a horizontal continuous, uniformly distributed nominal
load to the top of panel.
vi)**The nominal shear force to be resisted by any transverse section of
a panel.
vii)In addition to the main reinforcement on traffic face, secondary
reinforcement of area not less than 50 percent of the main
reinforcement shall be provided. The area of reinforcement on outer
face, both vertical and horizontal, shall not be less than 50% of that
in the traffic face. Spacing of reinforcement bars on any face shall not
exceed 200 mm.
viii)If concrete barrier is used as a median divider, the reinforcement is
required to be placed on both sides.
ix)For in-situ panels, the joint between panels shall extend from the top of the
panel down to not more than 25mm above the level of paved surface.
x)Specialist literature may be referred for design of attachment systems
and anchorages and their loading for precast concrete parapet panels.
xi)Equivalent static loading as given in Table-10 are also applicable to crash
barrier supported on friction slabs and friction slab too can be designed
for same static loading.
Notes :
80L
100 kN over 1.0m
Normal Containment
without shear transfer
between panels
(110+50H)L
Panel nominal shear
(kN/panel)**
Barrier Containment Panel nominal
Level
bending moment*
Table 10: Equivalent static nominal loads in situ and precast
concrete barriers applicable to panel lengths (L) 2.0 m to 3.5 m
Notifications
Accidental Combination
Seismic Combination
1.05
5.2
Construction
dead loads
(such as wt.
of launching
girder, truss
or cantilever
construction
equipment)
INDIAN HIGHWAYS
OCTOBER 2019
1.0
(2)
For
(1)
1.1 Dead load,
snow load if
present, SIDL
except surfacing
-
(7)
5.2
Construction
Dead Loads
(such as weight
of launching
girder, truss
or cantilever
construction
equipment
(1)
Accidental Combination
(3)
Accidental
Combination
(4)
Seismic
Combination
Loads
1.1
(2)
0.90
(3)
1.0
(b) When causing relieving
effect
(2)
1.0
(3)
Frequent
Combination
1.0
(4)
Quasi-permanent
Combination
1.1 Dead load, snow
load if present, SIDL
except surfacing,
and back fill Weight
(1)
Loads
1.0
(2)
Rare
Combination
Read
0.90
(5)
1.0
(3)
Frequent
Combination
1.0
1.0
(3)
Accidental
Combination
Ultimate Limit State
Basic Combination
1.35
2.2 Wind load during
construction and service
1.10
(4)
Read
(a) When causing adverse effect
1.4 Back fill weight
(1)
Seismic Combination
0.9
(7)
1.0
(4)
Quasi-permanent
Combination
1.0
1.0
(4)
Seismic
Combination
1.1
(6)
Overturning Restoring Overturning Restoring Overturning Restoring
or Sliding or or Resisting or Sliding or or Resisting or Sliding or
or
uplift Effect
Effect
uplift Effect
Effect
uplift Effect Resisting
Effect
Basic Combination
Table B.3 Partial Safety Factor for Verification of Serviceability Limit State
Rare Combination
(2)
-
(6)
Loads
Read
Table B.2 Partial Safety Factor for Verification of Structural Strength
-
(5)
Ultimate Limit State
For
-
(4)
Basic Combination
0.95
(3)
Loads
2.2 Wind load
construction during
service
1.4 Back fill weight
(1)
Loads
(2)
Overturning Restoring Overturning Restoring Overturning Restoring
or Sliding or or Resisting or Sliding or or Resisting or Sliding or or Resisting
uplift Effect
Effect
uplift Effect
Effect
uplift Effect
Effect
Basic Combination
(1)
Loads
For
B.1 Partial Safety Factors for verification of Equilibrium
Notifications
35
36
INDIAN HIGHWAYS
OCTOBER 2019
7
216
(page 60)
S.NO Clause No
4.0 Construction
Dead Loads
(weight. of
launching girder,
truss or cantilever
construction
equipment)
5.1 Water Current
5.2 Wave Pressure
6 Buoyancy
a)For Base
Pressure
b)For Structural
Design
Add new
(1)
1.1 Dead load,
Snow Load (if
present) SIDL
except surfacing
and Back Fill
Weight
1.2 SIDL Surfacing
Loads
1.0 or 0
1.0 or 0
1.0
0.15
1.0 or 0
1.0 or 0
1.0
0.15
0.15
1.0
1.0 or 0
1.0 or 0
1.0
1.75
1.35
1.0
1.0
1.0
Construction live load
Surfacing
When causing adverse effect
When causing relieving effect
For
b) For Structural Design
a) For Base Pressure
5.1 Water Current
5.2 Wave Pressure
6 Buoyancy
4.0 Construction Dead Load
1.2
(a)
(b)
2.1
c)
(1)
1.1 D
ead load, Snow Load (if
present) SIDL except surfacing
and Back Fill Weight
(a) When causing adverse effects
(b) When causing Relieving effects
Loads
0.15
1.0
1.0 or 0
1.0 or 0
1.35
1.35
1.75
1.0
1.35
1.0
0.15
1.0
1.0 or 0
1.0 or 0
1.0
1.0
1.0
1.0
1.0
1.0
by the vertical deflection of the girder combined with the rigidity of the joints.
216.3
effects are reduced to a minimum. In the absence of calculation, deformation stresses shall be assumed
to be not less than 16 percent of the dead and live loads stresses.
In prestressed girders of steel, deformation effects may be ignored.
216.2All steel bridges shall be designed, manufactured and erected in a manner such that the deformation
Delete
Read
0.15
1.0
1.0 or 0
1.0 or 0
1.35
1.35
1.75
1.0
1.35
1.0
0.15
1.0
1.0 or 0
1.0 or 0
1.0
1.0
1.0
1.0
1.0
1.0
Combination Combination
Seismic
Accidental
(1)
(2)
Combination Combination
(2)
(3)
(4)
(5)
Read
216
DEFORMATION EFFECTS (for Steel Bridges only)
216.1 A deformation effects is defined as the bending stress in any member of an open web-girder caused
1.0
1.0
1.75
1.35
1.0
1.35
Combination Combination
Seismic
Accidental
(1)
(2)
Combination Combination
(2)
(3)
(4)
(5)
For
Table B.4 Partial Safety Factor for checking of base Pressure and Design of Foundations
Notifications
2
1.0
1.0
Bearings and Connections (see note(VI) also)
Stoppers (Reaction Blocks)
Those restraining dislodgement or drifting away of
bridge elements.
3.0
3.0
1.5
1.0
1.0
(v) RCC/PSC Frame ( Refer Note VI)
(vi) Steel Framed
(vii) Steel Cantilever Pier
Bearings and Connections (see note(V) also)
Stoppers (Reaction Blocks)
Those restraining dislodgement or drifting
away of bridge elements.
1.0
1.0
1.0
2.5
2.5
Notes :
i)Bracing and bracing connection primarily carrying horizontal
seismic force for steel and steel composite superstructure, R
factor shall be taken as 3 where ductile detailing is adopted.
ii)Response reduction factor is not to be applied for calculation of
displacements of elements of bridge as a whole.
iii)When elastomeric bearings are used to transmit horizontal
seismic forces, the response reduction factor (R) shall be taken
as 1.0 for all substructure.
1.5
(vii) Steel Cantilever Pier
3.0
(iv) RCC Single Column
2.5
3.0
3.0
(iv) RCC Single Column
(vi) Steel Framed
2.5
3.0
(iii) R
CC Wall piers and abutments in longitudinal
direction (where hinges can develop)
1.0
(ii) RCC Wall piers and abutments transverse direction
(where plastic hinge cannot develop)
3.0
3.0
1.0
1.0
'R' WITH
DUCTILE
DETAILING
(i) Masonry / PCC Piers, Abutments
Substructure
BRIDGE COMPONENT
(v) RCC/PSC Frame ( Refer Note VII)
1.0
(ii) RCC Wall piers and
abutments
transverse direction (where plastic
hinge cannot develop)
1.0
'R'
WITHOUT
DUCTILE
DETAILING
(for Bridges in
Zone II only)
Read
(iii) RCC Wall piers and abutments in
longitudinal direction (where hinges
can develop)
1.0
'R' WITH
DUCTILE
DETAILING
(i) Masonry / PCC Piers, Abutments
Substructure
BRIDGE COMPONENT
Table 4.1 Response Reduction Factors (R)
For
Notes below
Notes:
Table 4.1
i.Bracing and bracing connection primarily carrying horizontal
(Page 26 & 27)
seismic force for steel and steel composite superstructure, R
factor shall be taken as 3 where ductile detailing is adopted.
ii.Response reduction factor is not to be applied for calculation of
displacements of elements of bridge as a whole.
iii.When elastomeric bearings are used to transmit horizontal
seismic forces, the response reduction factor (R) shall be taken
as 1.0 for all substructure. In case substructure and foundation
will remain in elastic state, no ductile detailing is required.
(Page 26)
S. Clause No. &
No Page No.
1 Table 4.1
Amendment No.2/IRC:SP:114/August, 2019 (Effective from 31st October, 2019)
To
IRC:SP:114-2018 “Guidelines for Seismic Design of Road Bridges”
Notification No. 25
Notifications
INDIAN HIGHWAYS
OCTOBER 2019
37
38
3
Title of Clause
4.7
(Page 30)
S. Clause No. &
No Page No.
INDIAN HIGHWAYS
OCTOBER 2019
iv)In case substructure & foundations are designed with R=1, no
ductile detailing is required.
v)Where plastic hinges are likely to be formed in any seismic zone
(including zone II), ductile detailing is mandatory at locations
of plastic hinges.
vi)Bearings and connections shall be designed to resist the lesser of the
following forces, i.e., (a) design seismic forces obtained by using
the response reduction factors given in Table 4.1 and (b) forces
developed due to over strength moment when hinge is formed in
the substructure. For calculation of overstrength moments, (Mo)
shall be considered as Mo=γ0 MRd γ0 = Over-strength factor
& MRD is plastic moment of section, for detail refer Chapter 7 .
Over-strength factors for Concrete members: γ0= 1.35 & for Steel
members: γ0 = 1.25
vii)
The shear force for over strength moments in case of cantilever
piers shall be calculated as Mo/h, “h” is height shown in
Fig. 7.1 in Chapter 7. In case of portal type pier capacity of all
possible hinges need to be considered.
viii)Capacity Design should be carried out where plastic hinges are
likely to form.
ix)The R factor for ductile behavior specified in Table 4.1 may
be used only if the location of relevant plastic hinges are
accessible for inspection and repair. Otherwise, under situation
of inaccessibility of plastic hinges the Factor R given in Table
4.1 shall be multiplied by 0.6; however, R value less than 1.0
need not be used.
4.7
Lateral Earth Pressure under Seismic Condition & Seismic in
Embedded portion of Structure
4.7.1 Lateral Earth Pressure under Seismic Condition
For seismic effects on earth pressure, the clause 214.1.2 of IRC-6-2017
shall be referred.
The modified earth pressure forces described in above clause need not
be considered on the portion of the structure below scour level.
4.7.2 Seismic in Embedded portion of Structure
For embedded portion of foundation at depths exceeding 30 m below
scour level, the seismic force due to foundation mass may be computed
using design seismic coefficient equal to 0.5Ah. For portion of foundation
between the scour level and up to 30 m depth, the seismic force due
to that portion of foundation mass may be computed using seismic
coefficient obtained by linearly interpolating between Ah at scour level
and 0.5Ah at a depth 30 m below scour level.
iv.Ductile detailing is mandatory for piers of bridges located in
seismic zones III, IV and V where plastic hinges are likely to form
and when adopted for bridges in seismic zone II, for which “R
value with ductile detailing” as given in Table 4.1 shall be used.
v.Bearings and connections shall be designed to resist the lesser
of the following forces, i.e., (a) design seismic forces obtained
by using the response reduction factors given in Table 4.1 and
(b) forces developed due to over strength moment when hinge
is formed in the substructure. For calculation of overstrength
moments, (Mo) shall be considered as Mo=γ0 MRd γ0 =
Overstrength factor & MRD is plastic moment of section, for
detail refer Chapter 7 . Over-strength factors for Concrete
members: γ0= 1.35 & for Steel members:
γ0 = 1.25
vi.
The shear force for over strength moments in case of cantilever
piers shall be calculated as MRD/h, “h” is height shown in Fig
7.1 in Chapter 7. In case of portal type pier capacity of all
possible hinges need to be considered.
vii
Capacity Design should be carried out where plastic hinges are
likely to form.
4.7 Seismic Effects on Earth Pressure & Dynamic Component
For seismic effects on earth pressure and dynamic component the clause
214.1.2 of IRC-6-2017 shall be referred.
The modified earth pressure forces described in above clause need not
be considered on the portion of the structure below scour level.
For embedded portion of foundation at depths exceeding 30 m below
scour level, the seismic force due to foundation mass may be computed
using design seismic coefficient equal to 0.5Ah. For portion of foundation
between the scour level and up to 30 m depth, the seismic force due
to that portion of foundation mass may be computed using seismic
coefficient obtained by linearly interpolating between Ah at scour level
and 0.5Ah at a depth 30 m below scour level.
Read
For
Notifications
INDIAN HIGHWAYS
10
9
8
7.3 (e)
( Page 47)
6.4.4
(Page 43)
6.4.3 (v)
(Page 43)
S. Clause No. &
No Page No.
4 Fig 5.1 (a) & (b)
(Page 35)
5
5.3
(Page 38)
6
6.3.1 Sr. V,
(Page 41)
7
6.3.2,
(Page 42)
v. The capacity protected regions of substructure may be designed
without ductility provisions.
Force demands for essentially elastic components adjacent to plastic
hinges should be determined by capacity-design principle, that is, jointforce equilibrium conditions; considering plastic hinge capacity at hinge
location multiplied by over strength factor in-principal direction of
earthquake. The over strength factors should not be used where plastic
hinges are not likely to be formed. Force demands calculated from linear
elastic analysis should not be used in capacity protected regions
v. In case, in-plane horizontal seismic forces are to be transmitted using
elastomeric bearings, they shall be checked using minimum dynamic
frictional value and minimum vertical loads, including combined effect
of vertical and horizontal components of earthquake. In such cases
suitable devices for preventing dislodgement of superstructure shall be
provided.
Where high damping elastomeric bearings are used to resist seismic
action, these may be designed to act as seismic isolation bearing for
which Chapter-10 shall be referred.
In bridges where pier heights are high……
Natural period T, secs
Read
The final step in the design is to determine the forces in the members
adjacent to plastic hinge which are to remain elastic, by capacity design
procedure explained in the following section. This includes sections of
pier outside the plastic hinge and the foundations
The final step in the design is to determine the forces in the members
adjacent to plastic hinge which are to remain elastic, by capacity design
procedure explained in the following section. This includes sections of
pier outside the plastic hinge and the foundations. For this purpose, the
combination of component of motion as given clause 4.2.2 for capacity
design effects is not applicable
6.4.4 Foundation
6.4.4 Foundation
i.Force demands on foundations should be based on capacity design i.Force demands on foundations should be based on capacity
principle that is, plastic capacity of bases of columns/piers multiplied
design principle that is, plastic capacity of bases of columns/
with an appropriate over strength factor. Foundation elements
piers multiplied with an appropriate over strength factor. Pile
should be designed to remain essentially elastic. Pile foundations
foundations may experience limited inelastic deformations; in
may experience limited inelastic deformations; in such cases these
such cases these should be designed and detailed for ductile
should be designed and detailed for ductile behavior
behavior
v.The capacity protected regions of substructure/foundation can be
designed elastically without ductility provisions.
Force demands for essentially elastic components adjacent to ductile
components should be determined by capacity-design principle, that is,
joint-force equilibrium conditions; considering plastic hinge capacity
at hinge location multiplied by over strength factor. The over strength
factors should not be used where plastic hinges are not likely to be
formed. Force demands calculated from linear elastic analysis should
not be used in capacity protected regions
v.
Wherever the elastomeric bearings are used, these bearing shall
accommodate imposed deformations and normally resist only nonseismic actions. The resistance to seismic action is provided by structural
connections of the deck to piers or abutments through suitable means.
In case, in-plane horizontal seismic forces are to be transmitted using these
elastomeric bearings, they shall be checked using minimum dynamic
frictional value and minimum vertical loads, including combined effect
of vertical and horizontal components of earthquake. In such cases
suitable devices for preventing dislodgement of superstructure shall be
provided.
Where high damping elastomeric bearings are used to resist seismic
action, these may be designed to act as seismic isolation bearing for
which Chapter-8 shall be referred.
In bridges where pier height are high…….
Natural period T,5
For
Notifications
OCTOBER 2019
39
40
INDIAN HIGHWAYS
12. 8.3.2
(Page 58)
S. Clause No. &
No Page No.
11 Fig 7.2
(Page 56)
Read
OCTOBER 2019
The transfer of force through connection between substructure and
superstructure is an important aspect in design of substructure.
The connections between supporting and supported members
shall be designed in order to ensure structural integrity and
avoid unseating under extreme seismic displacements. The piers
shall be designed to withstand shear forces corresponding to
the pier’s plastic hinge capacity. The maximum induced shear
The transfer of force through connection between substructure and
superstructure is an important aspect in design of substructure.
The connections between supporting and supported members
shall be designed in order to ensure structural integrity and
avoid unseating under extreme seismic displacements. The piers
shall be designed to withstand shear forces corresponding to
the pier’s plastic hinge capacity. The maximum induced shear
Cl. 8.3.2 Force Transfer mechanism from bearing to abutment Cl. 8.3.2 Force Transfer mechanism from bearing to abutment
and pier
and pier
For
Notifications
Type of Bridge
Simply Supported individual span
INDIAN HIGHWAYS
ERSM*
All heights
All heights
ERSM
OCTOBER 2019
ERSM#
ERSM
ERSM
All heights
Bridges with shock transmission units (STU), Seismic
isolation devices or Seismic dampers etc
>30 ◦
Main Span
<600m
All heights
ESAM/ERSM
ERSM
ERSM
All heights
Filled up Arch
All other Arch
Large
< 100 m radius
ERSM*
All heights
All Spans
All heights
Skew Angle
Cable Stay, Suspension spans
Curved in Plan
ERSM*
All heights
Bridges founded on site with sand or poorly graded sand with
little or no fines or in liquefiable soil in all seismic zones
Bridge
With
Difference in Pier Heights/Stiffness
Arch Bridges
ERSM
All heights
ERSM#
ERSM
ERSM#
ERSM*
ERSM*
ESAM/ERSM
ERSM
ERSM
ERSM#
ERSM*
ERSM*
Pier Height Method of analysis in Seismic Zone
II & III
IV & V
Up to 30m ESAM/ERSM ESAM/ERSM
Above 30 m
ERSM
ERSM
Up to 30m ESAM/ERSM
ERSM
Above 30 m
ERSM
ERSM
Up to 30m
ESAM
ERSM
Above 30 m
ERSM
ERSM
All heights
ERSM
ERSM
<150m between
exp. joints.
>150m between
exp. joints
All Spans
> 150m
60 to 150m
Span Length/
Condition
0 to 60m
Table 5.3 :- Method of Analysis on various Type of Bridges
#site Specific Spectrum for zone IV
& V preferable
Evaluation of liquefaction potential
shall be carried out as given in
Appendix A5
#site Specific Spectrum preferable
Refer Note 4
#site Specific Spectrum preferable
Spatial Variation of ground motion
to be considered
Refer Note 3
Remarks
Replace existing Table 5.3 with new table as given below:
in the piers shall be limited to the plastic hinge moment (or moments)
divided by the height of pier as ascertained in Chapters 4 and 7.
For use of elastomeric bearing in seismic zone IV&V reference shall be
made to clause 3.4.2
In seismic design, the fixed bearing shall be checked for full seismic force
along with braking / tractive force, ignoring the relief due to frictional
forces in other free bearings. The structure under the fixed bearing shall
be designed to withstand the full seismic and design braking / tractive
force.
in the piers shall be limited to the plastic hinge moment (or moments)
divided by the height of pier as ascertained in Chapters 4 and 7.
For Seismic Zone IV and V, use of elastomeric bearings for resisting
horizontal seismic actions by shear deformation, shall not be permitted.
In such cases PoT, POT Cum PTFE and Spherical Bearings shall be
adopted over elastomeric bearings for resisting seismic loads.
In seismic design, the fixed bearing shall be checked for full seismic force
along with braking / tractive force, ignoring the relief due to frictional
forces in other free bearings. The structure under the fixed bearing shall be
designed to withstand the full seismic and design braking / tractive force.
Table 5.3 Method of Analysis of Various Type of Bridges
Simply Supported individual span
Table 5.3
(Page 40)
Read
For
Right
Individual Span
Bridge or
Skew Up to
30 ◦ or
Continuous/Integral Bridges/Extradosed
curved
bridges
span
having
Bridges Located on Geological discontinuity
radius more
Major Bridges in "Near field or Bridges on
than 100m
soils consisting of marine clay or loose sand
( eg where soil up to 30m depth has an avg
SPT value≤10)
13
S. Clause No. &
No Page No.
Notifications
41
42
For
Read
9.2.4 (iii)
Page 80)
9.2.5.1,
(Page 80)
9.2.7.1
(Page 85)
9.2.7.2
(iii), below
second para(Page 86)
9.2.7.3
third para
(Page 87)
16
INDIAN HIGHWAYS
17
18
OCTOBER 2019
19
The connection shall be designed to withstand a shear resulting
from the load combination
1.2DL + 0.5LL plus the shear resulting from the application of
1.2MP in the same direction, at each end of the beam (causing
double curvature bending). The shear strength need not exceed the
required value corresponding to the load combination in 9.2.3
iii) The rigid and semi-rigid connections should be designed to
withstand a shear resulting from the load combination 1.2 DL +
0.5 LL plus the shear corresponding to the design moment defined
above in (i) and (ii) respectively.
9.2.7.1 Moment resisting frames shall be designed so that plastic
hinges form in the beams or in the connections of the beams to
the columns, but not in the columns. Depending on the detailing, a
moment resisting frame can be classified as either an ordinary moment
frame (OMF) or a special moment frame (SMF). Moment resisting
frames are usually provided in the steel piers, end diaphragms of
girder bridges and end portals (for wind) of through open web girder
bridges. A higher value of R is assigned to the SMF but more stringent
ductility detailing requirements need to be satisfied so as to achieve
the required plastic joint rotation θp (see Fig. 9.6)
The connection shall be designed to withstand a shear resulting from the load
combination
1.35 DL + 1.75 Surfacing + 0.2LL plus the shear resulting from the application of
1.2MP in the same direction, at each end of the beam (causing double curvature
bending). The shear strength need not exceed the required value corresponding to
the load combination in 9.2.3.
iii) The rigid and semi-rigid connections should be designed to withstand a
shear resulting from the load combination 1.35 DL + 1.75 Surfacing + 0.2 LL
plus the shear corresponding to the design moment defined above in (i) and (ii)
respectively.
9.2.7.1 Moment resisting frames shall be designed so that plastic hinges form at the
base of column or in the beams not supporting the superstructure or in their connection
to column. Plastic hinge should not form in the beam directly supporting superstructure
or at other location in the column. Depending on the detailing, a moment resisting
frame can be classified as either an ordinary moment frame (OMF) or a special
moment frame (SMF). Moment resisting frames are usually provided in the steel
piers, end diaphragms of girder bridges and end portals (for wind) of through open
web girder bridges. A higher value of R is assigned to the SMF but more stringent
ductility detailing requirements need to be satisfied so as to achieve the required
plastic joint rotation θp (see Fig. 9.6).
9.2.5.1 Member Strength in Compression
9.2.5.1 Member Strength in Compression
When ratio of required compressive strength of the member, Pr When ratio Pd (i.e., Pr / Pd) is greater than 0.4, the required compressive strength
to design axial compressive strength (without elastic buckling) of member shall be taken as greater of (a) & (b) below:
Pd (i.e., Pr / Pd ) is greater than 0.4, the required axial compressive
a) Factored compressive load. Pr as per Table B.2 of IRC:6
strength of member in the absence of applied moment shall also
b) Minimum of (i) & (ii) below
be determined from the load combination given in 9.2.3. The
i) Strength required using load combination given in clause 9.2.3.
required strength so determined need not exceed the maximum
ii) Direct factored load on column + maximum load transferred to column
load transferred to the member considering 1.25 times over
by connected beams and/or bracings considered over strength (1.25 times
strength of the connecting beam or bracing element.
nominal strength ) of such beam/bracing.
Where Pd is design axial compressive strength without elastic buckling
iii.
Bolted joints shall be designed not to share load in iii.
Bolts used in connections shall not be considered as sharing the load in
combination with welds on the same faying surface.
combination with welds on same faying surface. However, connections that are
welded to one member and bolted to the other member are permitted.
9.2.3 Load and Load Combinations
9.2.3
9.2.3 Load and Load Combinations
1. Earthquake loads and response reduction factor shall be as per these
(Page 79-80) 1. Earthquake loads and response reduction factor shall be as
per these guidelines.
guidelines.
2. In the limit state design of frames resisting earthquake loads, in
2. In the limit state design of frames resisting earthquake loads, in addition
addition to the load combinations given in Table B.1 to B.4 of
to the load combinations given in Table B.1 to B.4 of Annexure-B of
Annexure-B of IRC 6, the following load combination shall also
IRC:6, the following load combination shall also be considered as
be considered as required in 9.2.5.1, 9.2.6.2 and 9.2.7.3:
required in 9.2.5.1, 9.2.6.2 and 9.2.7.3:
a) 1.2 Dead Load (DL) + 0.5 Live Load (LL) ±2.5
a) 1.35 Dead Load (DL) + 1.75 Surfacing+ 0.2 Live Load (LL) + 2.5
Earthquake Load (EL); and
Earthquake Load (EL); and
b) 0.9 Dead Load (DL) & 2.5 Earthquake Load(EL).
b) 1.0 Dead Load (DL)+ 1.0 Surfacing + 2.5 Earthquake Load(EL).
15
14
S. Clause No. /
NO
Page No.
Notifications
20
10.1General,
from 2nd
para(Page 89)
Chapter 10,
Title,
( Page 89)
S.NO Clause No.
/ Page No.
SEISMIC ISOLATION & DAMPING DEVICES
This chapter deals with the design of bridges incorporating Seismic base
Isolation & damping devices. Some of the currently known seismic isolation
devices are:
i)
Low damping Elastomeric Bearing
ii)
High Damping Rubber Bearing (HDR)
iii) Lead-Rubber Bearing (LRB)
iv) Friction Pendulum System ( FPS)
Following types of damping devices in isolation system may be adopted:
i)
Viscous Damper
ii)
Friction Damper
iii) Visco Elastic Damper
iv) Hysteresis damper
Provision of isolation devices is optional and it may be decided by the designer
on a case to case basis. Seismic Isolation devices covered in this chapter are
permitted to be used for comparatively rigid structures where fundamental time
period ‘T’ of the structure without incorporation of seismic isolation devices
is less or equal to 1.0 sec. In the case of Type III soft soil, seismic isolation
devices shall be avoided.
The Reduction of response and control of displacement in isolation system can
be achieved by following methods:
i) By lengthening of the fundamental period of the structure (effect of
period shift in the response spectrum), which reduces forces but increases
displacements;
ii)By introducing a damping device in parallel with isolation devices, the
displacement at the isolation level can be limited and arrived at acceptable
level.
iii)Instead of introducing separate damping device one may adopt HDR or
LRB which can serve both as isolation bearing as well as a damping
device. Similarly FPS can serve both the purpose of period elongation as
well as damping.
Isolation Devices provide single or combination of the following functions:
i)Vertical-load carrying capability, combined with high lateral flexibility
and high vertical rigidity;
ii)
Energy dissipation (hysteretic, viscous, frictional);
iii) Lateral restoring capability;
iv)Horizontal restraint (sufficient elastic stiffness) under non-seismic service
horizontal loads
Strength and integrity of the Isolation Device used is of utmost importance, due
to the critical role of its displacement capability for the safety of the bridge.
For all types of Isolation Devices excepting simple elastomeric low damping
bearings and flat sliding bearings, the design properties shall be verified through
established test methods.
This chapter deals with the design of bridges incorporating Seismic
Insolation Devices. Some of the currently known seismic
isolation devices are:
i)
Hydraulic Viscous Damper
ii)
Elastomeric Bearing Damper (Low Damping Elastomer)
iii) High Damping Elastomeric Bearing Damper
iv) Lead-Rubber Bearing Damper
v)
Friction Damper
Provision of isolation devices is optional and it may be decided
by the designer on a case to case basis. Various types of isolation
devices have different mechanism of seismic force reduction.
Seismic Isolation devices covered in this chapter are permitted to
be used for comparatively rigid structures where fundamental time
period ‘T’ of the structure without incorporation of seismic isolation
devices is less or equal to 1.0 sec. In the case of Type III soft soil,
seismic isolation devices shall be avoided.
Reduction of response is achieved through either of the following
phenomena:
i)
By lengthening of the fundamental period of the structure
(effect of period shift in the response spectrum), which
reduces forces but increases displacements;
ii)
By increasing the damping, which reduces displacements and
may reduce forces;
iii) By a combination of the two effects (preferred).
Isolation Devices provide single or combination of the following
functions:
iv) Vertical-load carrying capability, combined with high lateral
flexibility and high vertical rigidity;
v)
Energy dissipation (hysteretic, viscous, frictional);
vi) Lateral restoring capability;
vii) Horizontal restraint(sufficient elastic stiffness) under nonseismic service horizontal loads
Strength and integrity of the Isolation Device used is of utmost
importance, due to the critical role of its displacement capability for
the safety of the bridge. For all types of Isolation Devices excepting
simple elastomeric low damping bearings and flat sliding bearings,
the design properties shall be verified through established test
methods.
Read
SEISMIC ISOLATION DEVICE
For
Notifications
INDIAN HIGHWAYS
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43
44
INDIAN HIGHWAYS
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25
24
23
Fig. 10.3,
(Page 93)
Note 2
(Page 92)
Fig. 10.2,
Title,
(Page 92)
10.3, ‘ag’
definition,
(Page 92)
S.NO Clause No.
/ Page No.
Below
21
Table 10.1
(Page 91)
22
Eq. 10.5
(Page 91)
Fig. 10.2: Acceleration Spectra
ag = design ground acceleration on rock or hard soil depending upon the
seismic zone
TD = Refer fig .10.2
Read
Replace existing Fig 10.3
Fig. 10.3: Composite stiffness of pier and isolator i
Note 2: Maximum Teff shall be restricted to 4 sec. Brides with higher Note 2: Maximum Teff shall be restricted to 4 sec. Bridges with higher Teff need
Teff need special precautions due to very low stiffness against
special precautions due to very low stiffness against horizontal action
horizontal action
Fig. 10.2: Acceleration and displacement spectra
ag =design ground acceleration on rocky substrata
corresponding to the importance category of the bridge
TD = value defining the …..spectrum
For
Notifications
26
10.7
(Page 95)
In case of Friction Sliding Dampers with flat or curved (preferred)
surface, parameters such as dynamic sliding friction, maximum
displacement after incorporating the device into the structure etc
are needed for the design of structure incorporating Friction Sliding
Dampers
In case of Fluid Viscous Dampers, viscous force displacement
parameters, viscous resistance, maximum displacement after
incorporating the device into the structure, velocity of movement
etc are needed for analysis and design of the structure incorporating
such devices.
In case of low-damping elastomeric bearing (viscous damping ratio
ξ ≤ 0.06), high-damping elastomeric bearing (viscous damping ratio
ξ equal to 0.10 to 0.20) and lead-rubber bearing, damping ratio of
the composite material and other related parameters are needed for
analysis and design of the structure incorporating such Seismic
Isolation Devices.
10.7 Properties of Isolation Devices
Design properties of the Seismic Isolation Devices shall be obtained
from the supplier. There are different sets of proprieties for different
types of Seismic Isolation Devices. Some of them are as follows:
10.7 Properties of Isolation Devices
Design properties of the Seismic Isolation Devices shall be obtained from the
supplier. There are different sets of proprieties for different types of Seismic
Isolation Devices. Some of them are as follows:
In case of low-damping elastomeric bearing (viscous damping ratio ξ ≤ 0.06),
high-damping rubber bearing (viscous damping ratio ξ equal to 0.10 to 0.20) and
lead-rubber bearing, damping ratio of the composite material and other related
parameters are needed for analysis and design of the structure incorporating
such Seismic Isolation Devices.
In case of Fluid Viscous Dampers, viscous force displacement parameters,
viscous resistance, maximum displacement after incorporating the device into
the structure, velocity of movement etc are needed for analysis and design of
the structure incorporating such devices.
In case of Friction Sliding Dampers with flat or curved (preferred) surface,
parameters such as dynamic sliding friction, maximum displacement after
incorporating the device into the structure etc are needed for the design of
structure incorporating Friction Sliding Dampers.
The required increased reliability of isolating system shall be implemented by
designing each isolator ‘i’ for increased displacement dbi,a
dbi,a
= y ISdbi,d
Eq. 10.15
Where y Is is an amplification factor (taken as 1.50) that is applied only on the
design displacement dbi,d in each isolation device i resulting from one of the
procedures specified in 10.2.
The maximum total displacement of each isolation device in each direction shall
be obtained by adding to the above increased design seismic displacement, the
offset displacement potentially induced by:
a) the permanent actions
b) the long-term deformations (post-tensioning, shrinkage and creep for
concrete decks) of the superstructure, and
c) 50% of the thermal action
All components of the isolating system shall be capable of functioning without
any unacceptable deformations at the total maximum displacements.
Note: The maximum reaction of hydraulic viscous dampers (see Eq. 10.11)
corresponding to the increased displacement dbi,a may be estimated by
multiplying the reaction resulting from the analysis times y IS α b / 2 where α b
is the exponent of velocity of viscous damper.
10.7.1 Variations in Properties of Seismic Isolation & Damping Devices
Nominal properties of the components of these devices undergo changes due to
ageing, temperature, loading history, contamination and wear. Usually higher
properties of components lead to higher design forces and lesser properties lead
to larger displacements. Hence, two sets of values, namely upper bound design
properties (UBDP) and Lower bound design properties (LBDP) need to be
considered in the analysis and design. However, in case the design displacements
calculated using Fundamental mode analysis based on UBDP and LBDP do not
differ by more than ±15%, response spectrum analysis or Time-history analysis
may use nominal design properties.
For determination of variation in properties, if required to be used in the
analysis, specialist literature may be followed.
Notifications
INDIAN HIGHWAYS
OCTOBER 2019
45
27
46
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10.8 Verification of Bridge Sub-structure and Superstructure with
Isolating System
The Seismic internal forces EEA, derived from analysis, in the substructures and
superstructure due to the design seismic action alone, shall be derived from the
results of an analysis in accordance with 10.2. The design seismic forces EE due
to the design seismic action alone, may be derived from the forces EEA, after
division by the Response Reduction Factor ‘R’ =1, i.e. FE = FE.A/R with R = 1.0.
All members of the structure should be verified to have an essentially elastic
behaviour as per the relevant clauses. The design horizontal forces of supporting
members (piers or abutments) carrying sliding bearings shall be derived from the
maximum friction values as per relevant clauses of the bearing design code.
In the case of sliding bearings as mentioned above and when the same supporting
member also carries viscous fluid dampers, then the design horizontal seismic
force of the supporting member in the direction of the action of the damper should
be increased by the maximum seismic force of the damper, refer eqn. 10.16.
When single or multiple mode spectral analysis is carried out for isolating systems
consisting of combination of elastomeric bearings and fluid viscous dampers
supported on the same supporting elements(s), the phase difference between
the maxima of the elastic and the viscous elements may be taken into account,
by the following approximation. The seismic force should be determined as the
most adverse of those corresponding to the following characteristic states:
a. At the state of maximum displacement. The damper forces are then
equal to zero.
b. At the state of maximum velocity and zero displacement, when the
maximum damper forces should be determined by assuming the
maximum velocity to be:
= ( f1 + 2ξ b f 2 )Se M d Where Se is determined from Table 10.1
Fmax
Eq. 10.17
f1 = cos[arctan(2ξb)]
Eq. 10.18a
displacements in the horizontal directions x and y.
No uplift of isolators carrying vertical force shall be permitted in
f 2 = sin[arctan(2ξb)]
Eq. 10.18b
the seismic design combination.
Where ξb is the contribution of the dampers to the effective damping ξ eff
Sliding elements shall be designed as per relevant clauses of the
of Eq. 10.1.
bearing design code.
The Seismic internal forces EEA, derived from analysis, in the At this state the displacement amounts to f d and the velocity of the dampers
1 ccd
d
substructures and superstructure due to the design seismic action
alone, shall be derived
to ν = f 2ν max
ν x.d and νydyd should be taken equal to the maximum total relative
Where εq,d is the shear strain calculated in accordance with relevant
clauses of the bearing design code. In this context the movements
times y IS α b / 2 where α b is the exponent of velocity of viscous
damper.
Isolation devices consisting of simple low-damping elastomeric
bearings should be verified for the action effects in accordance with
relevant clauses of the bearing design code, taking partial factor for
ν max = 2πdbdbd //TTeffeff
Eq. 10.16
material y m = 1.15. For simple low damping elastomeric bearings,
Where dbd is the maximum damper displacement corresponding to the design
in addition to the above verification, the following condition should
displacement dcd of the isolating system.
be verified:
c At the state of the maximum inertial force on the superstructure, that
εq,d ≤ 2.0
Eq. 10.16
should be estimated as follows:
Where y Is is an amplification factor (taken as 1.50) that is applied
only on the design displacement dbi,d in each isolation device i
resulting from one of the procedures specified in 10.2.
The maximum total displacement of each isolation device in each
direction shall be obtained by adding to the above increased design
seismic displacement, the offset displacement potentially induced
by:
d) the permanent actions
e) the long-term deformations (post-tensioning, shrinkage and
creep for concrete decks) of the superstructure, and
f) 50% of the thermal action
All component of the isolating system shall be capable of functioning
without any unacceptable deformations at the total maximum
displacements.
Note: The maximum reaction of hydraulic viscous dampers (see
10.11) corresponding to the increased displacement dbi,a may be
estimated by multiplying the reaction resulting from the analysis
10.8 Verification of Bridge Sub-structure and Superstructure
10.8
(Page 95-97) with Isolating System
dbi,a
= y ISdbi,d
Eq. 10.15
Notifications
Eq. 10.17
INDIAN HIGHWAYS
= ( f1 + 2ξ b f 2 )Se M d
f1 = cos[arctan(2ξb)]
f 2 = sin[arctan(2ξb)]
Where Se is determined from Table
Fmax
OCTOBER 2019
Eq. 10.19b
Eq. 10.19a
10.1
Eq. 10.18
Where dbd is the maximum damper displacement corresponding
to the design displacement dcd of the isolating system.
c.At the state of the maximum inertial force on the superstructure,
that should be estimated as follows:
ν max =
In the case of sliding bearings as mentioned above and when the
same supporting member also carries viscous fluid dampers, then
the design horizontal seismic force of the supporting member in
the direction of the action of the damper should be increased by the
maximum seismic force of the damper, see eqn. 10.17.
When single or multiple mode spectral analysis is carried out for
isolating systems consisting of combination of elastomeric bearings
and fluid viscous dampers supported on the same supporting
elements(s), the phase difference between the maxima of the elastic
and the viscous elements may be taken into account, by the following
approximation. The seismic force should be determined as the most
adverse of those corresponding to the following characteristic
states:
a.At the state of maximum displacement. The damper forces are
then equal to zero.
b.At the state of maximum velocity and zero displacement,
when the maximum damper forces should be determined by
assuming the maximum velocity to be:
from the results of an analysis in accordance with 10.2. The design
seismic forces EE due to the design seismic action alone, may
be derived from the forces EEA, after division by the Response
Reduction Factor ‘R’ =1, i.e. FE = FE.A/q with R = 1.0. All members
of the structure should be verified to have an essentially elastic
behaviour as per the relevant clauses. The design horizontal forces of
supporting members (piers or abutments) carrying sliding bearings
shall be derived from the maximum friction values as per relevant
clauses of the bearing design code.
In isolating systems consisting of a combination of fluid viscous dampers and
elastomeric bearings, without sliding elements, the design horizontal force
acting on supporting element(s) that carry both bearings and dampers for nonseismic situations of imposed deformation actions (temperature variation, etc.)
should be determined by assuming that the damper reactions are zero.
Notifications
47
48
f1d ccdd
and the velocity of
INDIAN HIGHWAYS
Appendix A-1 Illustration of elastic seismic acceleration method
Appendix A-2 Illustration of elastic response spectrum method
Appendix A-3 Illustration of Seimic Acceleration Method Preamble
Appendix A-4 Illustration of hydrodynamic Pressure on Bridge Piers
Appendix A-5 Illustration of Liquefaction of soil
29
30
31
32
OCTOBER 2019
33
Replace existing Appendix A-5 with new
Replace existing Appendix A-4 with new
Replace existing Appendix A-3 with new
Replace existing Appendix A-2 with new
Replace existing Appendix A-1 with new
Flow Chart, Flow Chart for analysis of bridges involving seismic isolators is Deleted Flow Chart
(Page 97)
shown below :
28
the dampers to ν = f 2ν max
In isolating systems consisting of a combination of fluid viscous
dampers and elastomeric bearings, without sliding elements, the
design horizontal force acting on supporting element(s) that carry
both bearings and dampers for non-seismic situations of imposed
deformation actions (temperature variation, etc.) should be
determined by assuming that the damper reactions are zero
At this state the displacement amounts to
ξ eff of expression 10.1.
Where ξb is the contribution of the dampers to the effective damping
Notifications
Notifications
Appendix-A1 (Reference Clause 5.2.1)
Illustration of Elastic Seismic Acceleration Method (ESAM)
elastomer bearings as shown in Fig. A1.1 below. In this
The elastic seismic acceleration method presented
here illustrates the computation of seismic forces in
method, fundamental time period "T" is calculated by
accordance with method specified in clause 5.2.1 of
using expression given in clause 5.2.1 and corresponding
Chapter 5. Application of this method is presented for a
Sa/g is worked out using Spectra shown in Fig. 5.1 (a) of
simple bridge having a simply supported spans resting on
Chapter 5.
DEFINE SEISMIC
PARAMETERS

DEFINE MEMBER
IDEALIZATION

DEFINE MEMBER
STIFFNESS

DEFINE MEMBER
LOADS

CALCULATE TIME
PERIOD & BASE
SHEAR
WORK FLOW FOR CALCULATING THE BASE
SHEAR WITH ESAM
Step 1: Define Seismic parameters
The variables involved in finding out the seismic
coefficient are as follows:
Direction for Seismic Analysis
= Longitudinal
Zone factor, Z The bridge is located in zone III. Therefore, as per Table 4.2:
Z
= 0.16
Importance factor, I
Fig. A1.2: Typical Transverse Cross Section of The Bridge
The bridge is categorized as Seismic class
"Important bridges".
Therefore, as per Table 4.3:
I
= 1.2
Response reduction factor, R As per Table 4.1, Note iii:
R
=1
Average response acceleration coefficient, Sa/g The soil strata is categorized as Medium stiff
soil sites.
Therefore, as per clause 5.2.1:
Sa/g
= 2.5
; 0 < T < 0.55s
= 1.36 / T
; 0.55s < T < 4.00s
= 0.34
; T > 4.00s
Step 2: Define member Idealization
Fig. A1.3: Load
Idealization
Fig. A1.4:
Fig. A1.5: Variation
Deflection of Pier
of Seismic
& Bearing
Coefficient
Note:
For the purpose of this analysis, pier is assumed to be
fixed at top of open foundation and mass is lumped at top
of bearing i.e., 10.05 m above top of open foundation.
Step 3: Define member stiffness
Fig. A1.1: Typical Elevation
The stiffness of Elastomeric bearing is calculated based on
INDIAN HIGHWAYS
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49
Notifications
the Shear rating of the bearing as follows:
RXY = Resultant of the forces resisting to translatory
motion,
n
= Total number of bearings on pier cap
=4
A
= Total plan area of bearing
= 500 x 500
G
= Shear modulus of bearing (IRHD 50) = 0.7 Mpa
obtained by vectoral addition of vX & vY (for stiffness
computation – unit deflection)
Te
= Total thickness of elastomer in shear
RXY/vXY
= (n A G)/Te
= 50 mm
(refer IRC 83 Part-II)
= 4x500 x 500 x 0.7
50
= 14000 N/mm
= 14000 kN/m
vXY = Maximum resultant horizontal relative displacement
Summary of member stiffness:
Member
Dimension
Pier cap
Pier
Section Properties
Depth
1.5 m
4.0 m
Area
Ixx
Width
7.32 m4
Length
2.8m
Iyy
14.93 m4
2.0m
Area
Ixx / Iyy
3.14 m2
Cracked
Ixx / Iyy
0.59 m
16.0 m2
21.33 m4
Diameter
Foundation
Elastomeric
bearing
Grade of concrete
(Mpa)
Modulus of
Elasticity (Gpa)
35
32
35
32
35
32
N/A
N/A
11.2 m2
0.78 m4
4
Depth
1.5 m
Width
4.0 m
Area
Ixx
Length
4.0m
Iyy
21.33 m
Thickness
0.05 m
Width
0.5 m
Rxy / vxx
14000 kN/m
Length
0.5 m
4
Note:
The stiffness of pier is reduced by 25% to cater for cracking of the element during seismic case. The same can be modified based on the
actual cracked stiffness with the help of rigorous analyses.
All other components are assumed to be uncracked. The same can be modified based on the actual cracked stiffness with the help of
rigorous analyses.
Step 4: Define Member Loads
Calculate equivalent stiffness of system:
Mass of superstructure (including deck slab) = 5000 kN
Stiffness of Elastomeric bearing, K1
Mass of crash barrier
= 480 kN
Stiffness of Pier, K2
Mass of wearing course
= 570 kN
Mass of CWLL (as applicable)
= N.A.
Total mass from superstructure
= 6050 kN
Mass of pier cap
= 11.20 x 1.50 x 25
= 420 kN
Equivalent stiffness of system
Mass of pier
= 3.14 x 8.50 x 25
= 667.25 kN
Step 5: Calculate time period & Base shear
Calculation of time period by approximate method:
50
INDIAN HIGHWAYS
OCTOBER 2019
= 14000 kN/m
= 55709 kN/m
= 11188.3 kN/m
Notifications
Hence, the force in kN required to be applied for 1mm
horizontal deflection:
F
= 11188.3/1000
= 0.87
= 11.19 kN
Calculate design seismic acceleration coefficient (Ah)
Note:
=
The stiffness of pier cap is not considered separately for the
sake of simplicity.
The length L is taken from the top of bearing to the top of
foundation.
Calculate the dead load idealized as a lumped mass:
The dead load idealized as a lumped mass, D
= Mass from superstructure +
Mass of pier cap +
Half mass of pier
= 6050 + 420 + 333.6
= 6803.6 kN
The time period based on the approximate method, T
= 1.56 sec
Calculation of Base shear:
Since time period is 1.56 sec, as per clause 5.2.1: Sa/g
= 1.36 / T; 0.55s < T < 4.00s
Calculate Sa/g
= 0.084
Calculate base shear:
S. Component
No.
Loads
(kN)
Design seismic
acceleration
coefficient (Ah)
Seismic
force
(kN)
1
Super
structure
5000.0
0.084
418.60
2
Crash barrier
480.0
0.084
40.19
3
Wearing
course
570.0
0.084
47.72
4
CWLL
0.0
0.084
0.00
5
Pier cap
420.0
0.084
35.16
6
Pier above
GL (7.5m)
588.8
0.084
49.29
7
Pier below
GL (1m)
78.5
0.083
6.52
8
Foundation
600.0
0.081
48.77
Base Shear:
=
646.24
Appendix-A2 Example 1 (Reference Clause 5.2.2)
Illustration of Elastic Seismic Response Spectrum Method (ERSM)
In this example, a bridge with two span continuous
superstructure resting on fixed and free bearings is
analyzed for assessment of seismic forces with ERSM as
per clause 5.2.2 and Fig. 5.1(b) of Chapter 5. Fig. A.2.1.1
shows the bridge elevation with pile foundation. The
DEFINE SEISMIC
PARAMETERS

DEFINE MEMBER
IDEALIZATION

example illustrates the mathematical modelling, member
properties for analysis, loading, determination of natural
frequency, mode shapes and calculation of base shear by
using a commercial software.
DEFINE MEMBER
STIFFNESS
WORK FLOW FOR CALCULATING THE BASE
SHEAR WITH ERSM
Step 1: Define Seismic parameters
The variables involved in finding out the seismic coefficient
are as follows:

DEFINE MEMBER
LOADS

Direction for Seismic Analysis
CALCULATE TIME
PERIOD & BASE
SHEAR
= Longitudinal
Zone factor, Z The bridge is located in zone III. Therefore, as per Table 4.2:
Z
= 0.16
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51
Notifications
Importance factor, I
The bridge is categorized as Seismic class
"Important bridges".
Therefore, as per Table 4.3:
I
= 1.2
Response reduction factor, R As per Table 4.1:
R
=3
Average response acceleration coefficient, Sa/g
The soil strata is categorized as Medium stiff soil
sites.
Therefore, as per clause 5.2.2:
Sa/g
= 1 + 15T
: T < 0.10s
= 2.5 ; 0.10s < T < 0.55s
= 1.36 / T
; 0.55s < T < 4.00s
= 0.34 ; T > 4.00s
Step 2: Define member Idealization
Fig. A2.1.3:
Fig. A2.1.4:
Variation of Seismic Coefficient
Member Idealization
Notes:
The depth of fixity is calculated based on IS 2911 (Part
1/Sec 2). In this example it is assumed as 6m from base
of pile cap.
The pile is modelled as a free-standing element from
bottom of pile cap to depth of fixity.
The base of pile is assumed as fixed at the depth of fixity.
Step 3: Define member stiffness
Summary of member stiffness:
Fig. A2.1.1: Typical Elevation
Member
Dimension
Depth
1.5
m
Area
12.6 m2
Pier cap Width
4.5
m
Ixx
8.23 m4
Iyy
21.26
m4
Area
4.91 m2
Length 2.8m
Pier
Pile cap
Diameter
2.5m
52
INDIAN HIGHWAYS
OCTOBER 2019
Pile
Ixx / Iyy 1.92 m4
Cracked 1.44 m4
Ixx / Iyy
Depth
1.8
m
Area
26.01
m2
Width
5.1
m
Ixx
56.38
m4
Iyy
56.38
m4
Area
1.13 m2
Length 5.1 m
Fig. A2.1.2: Typical Transverse Cross Section of The Bridge
Section
Properties
Diameter 1.2m
Ixx / Iyy 0.10 m4
Grade of Modulus
of
concrete
(Mpa) Elasticity
(Gpa)
35
32
35
32
35
32
35
32
Notifications
Notes:
The stiffness of pier is reduced by 25% to cater for cracking of the
element during seismic case. The same can be modified based on
the actual cracked stiffness with the help of rigorous analyses.
All other components are assumed to be uncracked. The same
can be modified based on the actual cracked stiffness with the
help of rigorous analyses.
Step 4: Define Member Loads
Mass of superstructure (including deck slab)
= 5000 kN x 2
= 10000 kN
Mass of crash barrier
= 480 kN x 2
= 960 kN
Mass of wearing course
= 570 kN x 2
= 1140 kN
Mass of CWLL (as applicable) = N.A.
Total mass from superstructure = 12100 kN
Mass of pier cap
= 12.60 x 1.50 x 25
= 472.5 kN
Mass of pier
= 4.91 x 1.0 x 25
= 122.8 kN/m
Mass of pile cap
= 26.01 x 1.80 x 25
= 1170.5 kN
Mass of pile
= 1.13 x 1.0 x 25
= 28.3 kN/m
Mode Shape – 1
Mode Shape –2
Summary of Time period & Modal participation factor:
Participation
Design
seismic
factor (%)
Frequency Time
Mode (Cycles/ Period
Sa/g acceleration
coefficient
Sec)
(Sec) Individual Cumulative
(Ah)
1
0.48
2.10
85.01
85.01
0.65
0.021
2
7.29
0.14
14.97
99.98
2.50
0.080
The shear force & bending moment diagram as output
from the commercial software is shown below:
Shear force at pier
base: 283kN
Step 5: Calculate time period & Base shear
Calculation of time period by commercial software:
The number of modes to be used in the analysis for
earthquake shaking along a considered direction,
should be such that the sum total of modal masses of
these modes considered is at least 90 percent of the
total seismic mass.
The mode shapes, time periods & participation factor are
calculated with the help of a commercial software.
Bending moment at pier
base: 5724 kNm
For foundation design, capacity design shall be done as per
Clause 7.3.4.3 (iv) of IRC:114
Appendix A-2 Example-2 (Reference Clause 5.2.2)
Illustration of Elastic Response Spectrum Method (ERSM)
This example illustrates the Elastic Response Spectrum
Method for computation of seismic forces as per clause
5.2.2 and Spectra shown in Fig.5.1(b) of IRC:SP:114.
The bridge analyzed is a simply supported bridge with a
pier height of 45m resting on open foundation. The spans
resting on pier are supported on fixed bearings on one side
and free bearings on other side of pier center. The example
illustrates the mathematical modelling, determination of
INDIAN HIGHWAYS
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53
Notifications
natural frequency, mode shapes, lateral seismic forces and
base shear in longitudinal and transverse directions using
a commercial software.
Design Data
I longitudinal @ top
I transverse @ top
=
=
4.17
39.17
m4
m4
=
=
=
10.16
9.54
52.38
m2
m4
m4
=
=
=
12.51
18.23
66.98
m2
m4
m4
Area of Pier section @ bottom =
I longitudinal @ bottom
=
I transverse @ bottom
=
15.04
31.11
82.84
m2
m4
m4
Section at Node 2:
Self-weight of Superstructure
+ SIDL =
10000 kN
Area of Pier section @ m2
I longitudinal @ m2
I transverse @ m2
Self-weight of Pier cap
=
1200
kN
Section at Node 1:
Live Load on superstructure
=
1500
kN
Seismic Zone
=
III
Area of Pier section @ m1
I longitudinal @ m1
I transverse @ m1
Zone Factor
Z =
0.16
Importance Factor
I =
1.5
Response Reduction Factor
R =
3.0
Grade of concrete
fck =
25 MPa
Section 4 at base:
Elastic Modulus of Concrete E =
3.00E+07
kN/sqm
Height of Pier =
45
Type of Soil =
Medium Stiff
m
Fig. A.2.2.1 : Pier Cross Section
Fig. A.2.2.2: Lumped Mass Model
Member properties:
Pier Section Properties
Section Properties
Top of Pier
Bottom of Pier
Breadth, b Depth, h Thickness, t
(m)
(m)
(m)
7
2
0.5
7
4
0.8
Pier Idealization:
The pier is considered as hollow and is divided into 3
sections of 15m height each.
Properties of the pier section are as below:
Section at Node 3:
Area of Pier section @ top
54
=
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8
m2
OCTOBER 2019
For Member 3
Area for section of member 3 =9.08 m2
Moment of Inertia in Longitudinal direction, I longitudinal
=6.86 m4
Cracked I longitudinal (Assuming 75% of uncracked)
= 6.86 x 0.75 = 5.14 m4
Stiffness of pier in Longitudinal direction, k3
= 1.37E+05 kN/m
Moment of Inertia in transverse direction, I transverse
=45.78 m4
Cracked I transverse (Assuming 75% of uncracked)
=
45.78 x 0.75 = 34.33m4
Notifications
Stiffness of pier in Transverse direction, k3
=
9.16E+05 kN/m
For Member 2
Area for section of member 2
=
11.33 m2
Moment of Inertia in Longitudinal direction, I longitudinal
=
13.89 m4
Cracked I longitudinal (Assuming 75% of uncracked)
=
13.89 x 0.75 = 10.42m4
Stiffness of pier in Longitudinal direction, k2
=
2.78E+05 kN/m
Moment of Inertia in transverse direction, I transverse
=
59.68 m4
Cracked I transverse (Assuming 75% of uncracked)
=
59.68 x 0.75 = 44.76 m4
Stiffness of pier in Transverse direction, k2
=
11.94E+05 kN/m
For Member 1
Area for section of member 1
=
13.77 m2
Moment of Inertia in Longitudinal direction, I longitudinal
=
24.67 m4
Cracked I longitudinal (Assuming 75% of uncracked)
=
24.67 x 0.75 = 18.50 m4
Stiffness of pier in Longitudinal direction, k1
=
4.93E+05 kN/m
Moment of Inertia in transverse direction, I transverse
=
74.91 m4
Cracked I transverse (Assuming 75% of uncracked)
=74.91 x 0.75 = 56.18 m4
Stiffness of pier in Transverse direction, k1
= 14.98E+05 kN/m
Average properties for member 1, 2 & 3 are provided as
given in the table below:
Member
I longitudinal (m4 )
I transverse (m4 )
Area (m2)
1
2
3
18.50
10.42
5.14
56.18
44.76
34.33
13.77
11.33
9.08
Load calculation:
Total horizontal load at m3 [DL + SIDL + wt. of pier
(7.5m ht.)]
=
12870 kN
Total horizontal load at m2 [Wt. of pier (15m ht.)]
=
3755 kN
Total horizontal load at m1 [Wt. of pier (15m ht.)]
=
4618 kN
Basic Steps in Response Spectrum Method:
Step-1
M
Frame Mass Matrix, M
m1
0
0
=
Step-2
K
0
m2
0
0
0
m3
Frame Stiffness Matrix, K
=
k1+k2
-k2
0
-k2
k2+k3
-k3
0
-k3
k3
Step-3 Determine Eigenvalues, ω2 by [K-ω2M]
= 0 for each Mode=ω12, ω22, ω32
Step-4 Determine Natural Frequency for each Mode
=ω1, ω2 & ω3
Step-5 Determine Natural Time Period, T for each mode
T1=2π/ω1
T2=2π/ω2
T3=2π/ω3
Step-6 Determine Eigenvectors φ (mode shapes) at each
Node for each mode, by [K-Mw^2] φ=0 for each Mode
φ11, φ21, φ31
φ12, φ22, φ32
φ13, φ23, φ33
for Mode 1
for Mode 2
for Mode 3
Step-7 Determination of Modal Participation Factors for
each Mode, Pk
Step-8 Determination of Modal Mass for each Mode,
Mk
Transverse seismic load
Total horizontal load at m3 [DL + SIDL +20% LL+ wt. of
pier (7.5m ht.)]
=
13170 kN
Total horizontal load at m2
[Wt. of pier (15m ht.)]
=
3755 kN
Total horizontal load at m1
[Wt. of pier (15m ht.)]
=
4618 kN
Longitudinal seismic load
Where,
g
= acceleration due to gravity,
φik = mode shape coefficient at node i in mode k,
Wi = seismic weight at node i of the structure, and
INDIAN HIGHWAYS
OCTOBER 2019
55
Notifications
n = number of nodes of the structure
MODAL BASE ACTIONS:
Step-9 Determination of Lateral Forces at each Node for
each Mode, Qik
Time Forces (in kN)
Mode Period
FY
FZ
(Sec) FX
Moments (kN-m)
MX
MY
MZ
1
1.06
0
897.2 0
0
0
37655
2
0.11
0
328.8 0
0
0
3975.5
3
0.04
0
58.2
0
0
433.5
Qik = AkØikPkWi
Where,
Ak = design horizontal acceleration spectrum value as per
Clause 5.2.2 using natural period Tk of mode k obtained
from dynamic analysis
Step-10
Mode, Vik
Determination of Node Shear in each
Step-11 Determination of Nodal Shear due to all Modes
by SRSS at each node, Vik
Step-12 Determination of Base Moment
Computer Output- The problem is analyzed by using
commercial software and results are presented below:
0
BASE SHEAR BY SRSS:
957 kN
BASE MOMENT BY SRSS:
37867 kN-m
To illustrate the Response Spectrum Method further
for obtaining lateral forces, nodal shears and
moments, manual calculations are presented for steps
7 to 12 after picking up values of Time Period and
Eigenvectors from Computer output.
LONGITUDINAL DIRECTION
Mode Shapes-Longitudinal DIRECTION
(A) Longitudinal Direction
Mode
Frequency
(Hz)
Time
Period (sec)
Modal
Contribution
%
1
0.51
1.98
78.61
2
4.20
0.238
15.62
3
11.97
0.084
5.77
Modal Base Actions:
Time
Period
Mode
(Sec)
Forces (in kN)
Moments (kN-m)
FX
FY
FZ
MX
MY
MZ
1
1.98
0
0
459.3
0
19388.5
0
2
0.238
0
0
331.9
0
4623.7
0
3
0.084
0
0
110.3
0
893.3
0
Base Shear By Srss:
577 kn
Base Moment By Srss:
19952 kn-m
(B) Transverse Direction
Mode
Frequency
(Hz)
Time Period
(sec)
Modal
Contribution%
1
0.94
1.06
80.52
2
8.80
0.11
15.26
3
24.60
0.04
4.22
56
INDIAN HIGHWAYS
OCTOBER 2019
Fig. A.2.2.3: Eigenvectors
Mode-1
Mode-2
Mode-3
φ31
1.00
φ32
-0.16
φ33
-0.05
φ21
0.46
φ22
1.00
φ23
0.65
φ11
0.12
φ12
0.55
φ13
-1.00
Calculation of Modal Mass
Where,
g = acceleration due to gravity,
Notifications
Qik = mode shape coefficient at node i in mode k,
Wi = seismic weight at node i of the structure,
n= number of nodes of the structure
W3 =
12870 kN
W2 =
3755 kN
W1 =
4618 kN
Total (M)=
21243 kN
M1 =
1702 kN
M2 =
337 kN
M3 =
124 kN
Modal Contribution of various Modes
Mode 1= 100.M1/M
Mode 2= 100.M2/M
Mode 3= 100.M3/M
=
=
=
78.60 %
15.58 %
5.74 %
k = Mode Number
Lateral Force
Mode-1
Mode-2
Mode-3
Q3k
390 kN
-158 kN
23 kN
52 kN
292 kN
-98 kN
Q1k
16 kN
197 kN
185 kN
Q2k
Nodal Shear
Shear at each level for each mode is given by
Nodal
Shear
Mode-1
Mode-2
Mode-3
SRSS
V3
390 kN
-158 kN
23 kN
421.5 kN
442 kN
134 kN
-74 kN
468.2 kN
V1
459 kN
331 kN
110 kN
578.3 kN
V2
Refer Fig. A2.2.4
Mode Participation Factors
Base Moments (kn-m)
P1 = 1.10
P2 = 0.78
P3 = -0.44
Mode-1
Mode-2
Mode-3
SRSS
19365
4600
885
19923
Mode-1 base moment
Calculation of design lateral force (Qik):
Design acceleration coefficients and lateral forces are
calculated as per Cl. 5.2.2 of IRC:SP:114-2018
= 390x45+52x30+16x15 = 19365 kN-m
Mode-2 base moment
= -158x45+292x30+197x15 = 4600 kN-m
Mode-3 base moment
= 23x45-98x30+185x15 = 885 kN-m
I
Z
I
R
= 0.16
= 1.5
= 3.0
Response Spectra is chosen for Medium Stiff Soil Type
Ref: Cl.5.2.2 and Fig. 5.1(b) of IRC:SP:114-2018
Mode-1
Mode-2
Mode-3
Tk
1.98 Sec
0.24 Sec
0.08 Sec
Sa/g
0.69
2.50
2.26
Ak
0.027
0.10
0.09
Qik = AkØikPkWi
Where,
Ak =design horizontal acceleration spectrum value as per
Cl.5.2.2 using natural period of Tk of mode k obtained
from dynamic analysis
Fig. A.2.2.4: Shear Force Diagram
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OCTOBER 2019
57
Notifications
TRANSVERSE DIRECTION
Mode Participation Factors
Mode participation factors are given below:
Mode Shapes-Transverse Direction
P1 =
1.10
P3 =
-0.36
P2 =
0.73
Calculation of design lateral force (Øik):
Design acceleration coefficients and lateral forces are
calculated as per Cl. 5.2.2 of IRC:SP:114-2018
Mode-1
Mode-2
Z=
I=
R=
Mode-3
φ31
1.00
φ32
-0.18
φ33
-0.06
φ21
0.50
φ22
1.00
φ23
0.78
φ11
0.14
φ12
0.67
φ13
-1.00
Fig. A.2.2.5: Eigenvectors
Calculation of Modal Mass
W3 =
13170 kN
W2 =
3755 kN
W1 =
4618 kN
Total (M)=
21543 kN
M1 =
1768 kN
M2 =
335 kN
M3 =
92
0.16
1.5
3.0
Response Spectra is chosen for Medium Stiff Soil Type
Ref: Cl. 5.2.2 of IRC:SP:114-2018 and Fig.5.1(b)
Qik = AkØikPkWi
Where,
Ak = design horizontal acceleration spectrum value as per
5.2.2 using natural period Tk of mode k obtained from
dynamic analysis
Mode-1
1.06 Sec
1.28
0.051
Tk
Sa/g
Ak
Mode-2
0.11 Sec
2.50
0.10
Mode-3
0.041 Sec
1.62
0.065
Nodal Shear is given by:
kN
k=Mode No.
where,
g= acceleration due to gravity,
Qik = mode shape coefficient at node i in mode k,
Wi = seismic weight of node i of the structure,
n= number of nodes of the structure
Mode 1= 100.M1/M =
Mode 2= 100.M2/M =
Mode 3= 100.M3/M =
58
80.53 %
15.23 %
4.20 %
INDIAN HIGHWAYS
Lateral
Force
Q3k
Q2k
Q1k
Mode-2
Mode-3
748 kN
107 kN
36 kN
-168 kN
273 kN
224 kN
19 kN
-68 kN
108 kN
Nodal Shear
Nodal
Shear
V3
V2
V1
Mode-1
748 kN
855 kN
891 kN
Refer Fig. A 2.2.6
OCTOBER 2019
Mode-1
Mode-2
-168 kN
104 kN
328 kN
Mode-3
19 kN
-49 kN
58 kN
SRSS
766.5 kN
862.5 kN
951.5 kN
Notifications
Base Moments (kN-m)
Mode-1
Mode-2
Mode-3
SRSS
37402
3962
431
37614
Mode 1 base moment
= 748 x45 + 107 x 30 + 36 x 15
= 37402 kN-m
Mode 2 base moment
= -168 x45 + 273 x 30 + 224 x 15 = 3962 kN-m
Mode 3 base moment
= 19 x45 -68 x 30 + 108 x 15)
= 431 kN-m
Fig.A2.2.6: Shear Force Diagram
APPENDIX –A-3
(Reference Clause 7.3)
ILLUSTRATION OF CAPACITY DESIGN METHOD FOR MEMBERS WITH DUCTILE BEHAVIOUR
This Appendix includes worked out example for Capacity
Design to be followed for checking the member sections
adjacent to ductile components/plastic hinges in accordance
with method described in Chapter 7.
The procedure for Capacity design mainly includes the
following steps:
¾¾ Capacity Design Effects shall be treated as Ultimate
loads
A typical pier analysed and designed for Capacity Design
is shown in Fig.A3.1 and Fig.A3.2.
¾¾ Design of Section with IRC:112 for Load
Combinations of IRC:6 by Limit State Method
¾¾ Design of Plastic Hinge including its location, height
and ductile detailing as specified in Clause 7.5.2 &
7.5.4 of Guidelines
¾¾ Determination of MRd, Design Flexural Strength of
section in Longitudinal and Transverse directions
at location of plastic hinge for reinforcement and
dimensions provided
¾¾ Computation of Over Strength Moment Mo by
multiplying MRd with Over Strength Factor γ
o
¾¾ Computation of Capacity design Moment, Mc and
Shear Vc for the member sections outside the plastic
hinge
¾¾ Design of Section outside plastic hinge for Mc & Vc
in accordance with Clause 7.5.3
¾¾ Design of Foundation for Moment Mo and Shear Vc
computed at base of pier
Fig.A3.1: Section in Transverse Direction
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OCTOBER 2019
59
Notifications
3
SIDL (Surfacing)
SIDL-V-Each
side
4
Live load (LL) Reaction Without Impact Factor
i
ii
iii
Pmax(LL)
Q1
Max MT(LL)
Q2
Max ML(LL)
Q3
620
0
0
0
0
1982
0
0
238
3164
1321
0
0
159
4416
1326
0
0
1061
2121
Where,
SIDL -Super Imposed Dead Load
P -Axial Force
HT
-Horizontal Force along
Direction
Fig.A3.2: Section in Longitudinal Direction
(both bearings fixed)
1. Material Properties:
fck
= 45 N/mm2
Grade of concrete for Pile foundation
fck
= 35 N/mm2
Grade of steel reinforcement for
Substructure and Pile foundation
fy
= 500 N/mm2
Clear Cover to reinforcement for Pile
foundation
c
= 75 mm
Clear Cover to reinforcement for
Substructure
c
= 40 mm
Gross Area of Pier section
Ac
= 3570000 mm2
2. Calculation of Seismic Forces:
Table 1: Un-Factored loads from Superstructure at bearing
level
1
2
60
P
HL
(kN)
(kN)
Dead Load
(DL) – Each
Superstructure
7710
0
SIDL (permanent)
SIDL-F-Each
side
700
0
INDIAN HIGHWAYS
HT
MT
ML
(kN) (kNm) (kNm)
0
0
0
0
OCTOBER 2019
HL -Horizontal Force along Longitudinal
Direction
MT -Transverse moment
ML -Longitudinal moment
Pmax(LL)
-Maximum Vertical load case
Max MT(LL)
Max ML(LL)
-Maximum Transverse moment case
-Maximum Longitudinal moment case
Superstructure Mass for longitudinal seismic
(DL + SIDL) =
18060 KN
Grade of concrete for Substructure
S.
N. Description
Transverse
0
0
Superstructure Mass for transverse seismic
(DL+SIDL+0.2 x LL) =
9426 KN
T, Time Period of the system along Longitudinal
Direction =
1.18 sec
T, Time Period of the system along Transverse Direction =
0.75 sec
Taking
Zone factor =
0.24
Importance factor
=
1.2
Response Reduction factor, R = 3
Considering medium type soil
Ah Long
=
0.164
Ah Trans
=
0.263
Load Factor for Seismic
Combination =
1.5
Base Shear un-factored Seismic Combination in Longitudinal
Direction:
Due to superstructure= 987.3 KN with lever arm=10.5m above
pier base
Notifications
Due to pier+ pier cap=61.23 KN with lever arm=6.0m above
pier base
Factored Ultimate Base shear with
R=1 =1.5*(987.3+61.23)*3=4718 KN
(1)
Base Shear un-factored Seismic Combination in Transverse
Direction:
Due to superstructure= 826.38 KN with lever arm=12.5m above
pier base
Due to pier+ pier cap=98.19 KN with lever arm=6.0m above
pier base
Factored Ultimate Base shear with
R=1 =1.5*(826.38+98.19)*3=4161 KN
(2)
Table 2: Braking forces at the base of Pier-unfactored
S r.
Description
No.
ML
HL HT
(kN) (kN) (kN) (kNm)
P
MT
(kNm)
1
Braking Force under seismic Combination, Fb
i
Pmax(LL)
0
284
0
2982
0
ii
Max MT(LL)
0
208
0
2184
0
iii
Max ML(LL)
0
284
0
2982
0
b
1.35(DL
+SIDL-F) +
1.75(SIDL-V)
+ 0.2(Q2) +
0.2(Fb) +1.5Feq
14215
513
1387
4862
17262
c
1.35(DL
+SIDL-F)
+1.75
(SIDL-V) +
0.2 (Q3) +
0.2(Fb) +1.5Feq
14216
529
1387
5042
16803
3. Design of Section:
The reinforcement detailing of the Pier section at the base
and at the curtailment level is shown in Figure A3- 3.
Curtailment level is assumed to be 6m above the ground
level.
Table 3: Summary of forces at the base of Pier ULS
Seismic with R=3
Sl.
No
Description
P
HL
(kN)
(kN)
HT
ML
MT
(kN) (kNm) (kNm)
1
Earthquake along Longitudinal Direction
a
1.35
(DL+SIDL-F) +
1.75 (SIDL-V) 14347
+ 0.2(Q1) +
0.2(Fb) + 1.5Feq
1630
b
1.35(DL
+SIDL-F) +
1.75(SIDL-V) 14215
+0.2(Q2) +
0.2(Fb) + 1.5Feq
1614
416
16569 5797
c
1.35(DL
+SIDL-F) +
1.75(SIDL-V)
+0.2(Q3) +
0.2(Fb) +1.5Feq
1630
416
16909 5338
2
Earthquake along Transverse Direction
a
1.35(DL
+SIDL-F) +
1.75(SIDL-V) 14347
+ 0.2(Q1) +
0.2(Fb) + 1.5Feq
14216
416
16745 5546
At the base of Pier
529
1387
4878
17011
At curtailment level
Figure A3. 3: Reinforcement Detailing of the Pier Section
INDIAN HIGHWAYS
OCTOBER 2019
61
Notifications
4. Design Flexural Strength of Section:
At ULS, the design flexural strength of the section in
orthogonal directions is estimated for maximum vertical
load case.
In computing MRd, biaxial moment under the permanent
effects and seismic effects corresponding to the design
seismic action in the selected direction shall only be
considered as per clause 7.3.4.2.
Ultimate axial force, NED (At the base of
Pier)
= 14347 kN
Design Flexural Strength along
Longitudinal Direction, MRd,L
= 27660 kNm
Distance between ground level to the top
of Pier Cap, h
= 10.25 m
Moment due to Live Load (Longitudinal
Direction) = 0.2 x 238
= 48 kNm
Moment due to Live Load (Transverse
Direction) = 0.2 x 3164
= 634 kNm
Maximum Braking Force = 0.2 x 284
= 57 kN
Design Flexural Strength along Transverse
= 29390 kNm
Direction, MRd,T
Factored Moments (ULS) due to non-seismic actions, i.e. live
load and braking force :Along Longitudinal Direction
= 48 + 57 x 10.25
= 632 kNm
Along Transverse Direction
= 634 kNm
5. Over Strength Moment, Mo:
The procedure to calculate the capacity moment and
shear is applied separately for each of the two horizontal
components of the design seismic action. As per clause
7.3.4.2 (a) the over-strength moment of the sections due to
plastic mechanism is obtained by multiplying the design
flexural strength of the section with appropriate overstrength factors.
Over-strength factor for concrete substructures, γo = 1.35
As per clause 7.3.4.2 (b) of this Guideline, the over strength
factor has to be multiplied with a factor ‘K’ if the value of
normalized axial force ‘ηk’ is greater than 0.08.
Where, ηk= NED/Acfck
= (14682 x 1000) / (3570000 x 45)
=0.091 > 0.08
Since the value of normalized axial force, ηk, is more than
0.08, the over-strength factor requires modification as
below:
= 1.0002
K = [1+2(ηk - 0.08)2]
Thus, γo = 1.0002 x1.35 = 1.35
62
INDIAN HIGHWAYS
OCTOBER 2019
Fig. A3.4: Capacity Moment Diagram
The over-strength factor to be considered
for Pier section
= 1.35
Over strength moment at the base of Pier
along Longitudinal Direction, Mo,L
= 1.35 x 27660
= 37341 kNm
Over strength moment at the base of Pier
along Transverse Direction, Mo,T
= 1.35 x 29390
= 39677 kNm
6. Capacity Design:
6.1 For Capacity Design Moment Mc:
Curtailment of longitudinal bars, if any, should be done at such
a level that the design flexural strength of the section at the
curtailed level (MRd,curtailed) should be greater than the capacity
moment (Mc) at the curtailed level (Refer Fig.A3-4 )
Ultimate axial force, NED (At curtailment
level)
= 13893 kN
Design Flexural Strength at curtailed level = 22840 kNm
along Longitudinal Direction, MRd,L,
Design Flexural Strength at curtailed level
= 25980 kNm
along Transverse Direction, MRd,T,
Capacity moment at curtailed section along = 15483 kNm
<22840 kNm
Longitudinal Direction,
(MRd long)
Mc,L, curtailed = 37341 x (10.25-6)/10.25
Capacity moment at curtailed section along = 17420 kNm
Transverse Direction,
<25980 kNm
Mc,T, curtailed = 39677 x (10.25-6)/10.25
(MRd trans)
Hence, the design flexural strength of the section at
curtailed level is more than the capacity moment at the
same level.
¾¾ Within members having plastic hinges, the Mc at the
vicinity of hinge shall not be taken greater than MRd
of the hinge -Clause 7.3.4.2(d) of Guidelines.
Notifications
6.2 For Capacity Design Shear Vc in Pier
As per section 7.8 of this Guideline, the increase of
moments of plastic hinges, ΔM, is obtained by deducting
the moment due to non-seismic actions, i.e. live load and
braking force (considering appropriate load factors) from
the over-strength moment of the section along both the
directions. The increase in moment of plastic hinge is:
Along Longitudinal Direction, ΔML
Checks should be carried out to ensure that the plastic
hinge region, pier sections beyond plastic hinge region
and foundation have shear strength greater than the Final
Capacity Design shear Vc of the section along both the
directions.
6.3 Bearings:
Bearings and connections are to be designed for lesser of
the following forces:
= 37341 - 632
Along Transverse Direction, ΔMT
= 36709 kNm
i) Seismic forces obtained using Response reduction
factor,
= 39043 kNm
R=1 as applicable for assessment of bearings.
= 39677 - 634
As per clause 7.3.4.2 (e), Capacity Design shear
corresponding to this increase in moment is Obtained as:
ii) Forces developed due to over strength moment when
hinge is formed in the substructure
Vc = (∑ΔM) / h where ∑ΔM =∑Mo
Hence the design seismic forces for bearing design are:
Shear Along Longitudinal Direction
Along Longitudinal Direction, lesser of (1) and (3)
= ΔML / h = 36709/10.25 = 3582 kN
Shear Along Transverse Direction
(3)
(4)
= ΔMT / h =39043/10.25
= 3810 kN
The factored shear due to non-seismic actions (braking
force for this example) is then added to the shear due to
design seismic forces so as to obtain the Final Capacity
design shear along both the directions.
Final Capacity Design Shear in
= 3639 kN
Longitudinal Direction = 3582+ 57
Final Capacity Design Shear in Transverse
= 3810 kN
Direction
=
3582 kN
Along Transverse Direction, lesser of (2) and (4)
=
3735 kN
6.4 Capacity check for Pile Foundation:
The foundation is capacity protected by designing it for
Over strength Moment Mo and Capacity Design Shear Vc
in both the directions separately. The summary of forces
acting at the base of pile cap for the considered maximum
vertical load case in Longitudinal and Transverse is given
in Table 4. The number of piles is considered as 4 at a
spacing of 4.5 m in both directions.
Table 4: Summary of forces at the base of Pile cap
Description
Longitudinal
Case
Transverse
Case
Seismic
Seismic
Reactions on Pile in kN
Hor. Load on
Pile in kN
P
HL
HT
ML
MT
kN
kN
kN
kNm
kNm
P1
P2
P3
P4
17218*
3639
0
37341
634
8524
8383
226
-85
910
17157*
57
3810
48
39677
8704
-115
8693
-125
953
*Including soil weight above pile cap
The depth of fixity is assumed to be 9 m from the pile cap
bottom. The reduction factor for fixed head pile is assumed
to be 0.8 as per Fig. 5 of IS 2911(Part 1/Sec 2).
Maximum moment on a pile is observed to be
Along Longitudinal Direction
=
910 x 9/2x 0.8 = 3276 kNm
Along Transverse Direction
=
953 x 9/2x 0.8 = 3431 kNm
The pile diameter is assumed to be 1.2 m and the corresponding
reinforcement assumed is 19 numbers of (32+20mm) bundled
bars. For the above said pile, the capacity at the minimum axial
load i.e. -85 kN and -125 kN along longitudinal and transverse
direction respectively is found out to be 3575 kNm and
3484 kNm respectively. The capacity of the Pile for longitudinal
and transverse seismic case is more than the maximum moment
on the pile.
INDIAN HIGHWAYS
OCTOBER 2019
63
Notifications
APPENDIX - A4
(Reference Clause 4.8)
ILLUSTRATION OF HYDRODYNAMIC FORCES ON BRIDGE
SUBSTRUCTURE & FOUNDATION
Example : Calculation of hydrodynamic forces in case
of a bridge with Well Foundation, located in Seismic
Zone IV, with design horizontal seismic coefficient, Ah
= (Z/2) x (I/R) x (Sa/g) = 0.12 [i,e. Assuming Sa/g = 2.5;
I=1.2; Z=0.24; R=3.0 : Ah = (0.24/2) x (1.2/3.0) x 2.5]
Design parameters : Pier Diameter, d1 = 2.4m; Pier
Height below HFL, h = 6.218m, Well Diameter, d2 = 5.5m,
Overall height from HFL to Scour Level, H = 31.09m,
Well Height upto scour level = (H-h) = 24.872m [Refer
Fig. A4-1]
= C3F1 \
= 1.0 x 2.464t = 2.464t
Point of application of resultant force from base of pier
= C4h = 0.4286 X 6.218 = 2.665m
Bending moment at the base of pier (Well cap level) due
to hydrodynamic force on pier
= 2.464 x 2.665 = 6.566tm
The force distribution is worked out in Table 1, below, and
shown in Fig. A4-2
Table 1: Force Distribution on pier
(Refer portion A-B-C in Fig. A4-4)
C1
0.1
0.2
0.3
0.4
0.5
0.6
0.8
1.0
C1h
0.6218
1.2436
1.8654
2.4872
3.1090
3.7308
4.9744
6.2180
C2
0.410
0.673
0.832
0.922
0.970
0.990
0.999
1.000
C2 Pb1 (t/m)
0.195
0.319
0.395
0.438
0.460
0.470
0.474
0.475
Fig. A4.1
Hydrodynamic force on pier, F1 = CeαhWe
Pier Portion:
For pier portion consider enveloping cylinder of height h
and radius r1.
For pier portion,
(Refer Table 4.4)
Weight of water in enveloping cylinder for pier
Hydrodynamic force on pier, F1 = Ceαh We1
F1 = 0.73 x 0.12 x 28.129 = 2.464t
For Pier,
Resultant force at base of pier
64
INDIAN HIGHWAYS
OCTOBER 2019
Fig. A4.2
(b) Well Portion:
For well portion consider enveloping cylinder of height
H and radius r2. Deduct from it the enveloping cylinder of
height h and radius r2 to determine hydrodynamic effect
on well portion only. Thus hydrodynamic force on well
portion is obtained as follows:
For well foundation,
Notifications
Hydrodynamic force on well portion only= F2 –F3,
Where:
Table 2: Force Distribution on well
F2 = force acting on complete height H, enveloping radius
r2 (Refer portion A-B-D in Fig. A4.4
C1
C1h
C2
C2 Pb2(t/m)
0.2
0.6218
0.673
1.680
F3 = force acting on pier height h, enveloping radius
r2(Refer portion A-E-F in Fig. A4.4
0.3
9.3270
0.832
2.077
0.4
12.436
0.922
2.302
0.5
15.545
0.970
2.422
0.6
18.654
0.990
2.472
0.8
24.872
0.999
2.472
1.0
31.090
1.000
2.497
F2 = Ceαh We2
We2 = π x 2.752 x 31.09 = 738.645 t
F2 = 0.73 x 0.12 x 738.645 = 64.705 t
Point of application of F2 (resultant on H) from scour level
(C1 = 1.0),
C4H = 0.4286 x 31.09 = 13.325 m
Resultant force on height h (for C1 = h/H = 0.2)
F3 = C3 F2
F3 = 0.093 x 64.705 = 6.017 t
Point of application F3 (resultant on h) from scour level
(for C1 = 0.2)
= C4 H = 0.8712 x 31.09 = 27.085 m
The net hydrodynamic force acting on well portion only
F2 – F3 = 64.705-6.017 = 58.688 t
Bending moment at scour level due to hydrodynamic
force on well
=F2 x 13.325 - F3 x 27.085
= 64.705 x 13.325 – 6.017 x 27.085
= 699.224tm
Fig. A4.3
Fig. A4-4 below shows the final forces acting in pier and
well foundation
Total shear force and bending moment at scour level
Total shear force at scour level
= Hydrodynamic force on pier + Hydrodynamic force
on well
= 2.464 + 58.688 = 61.152 t
Total bending moment at scour level
= Moment of force F1 + Net Moment of force F2 and F3
= 2.464 (2.665 + 24.872) + 699.224
= 67.851 + 699.224 = 767.075t
The force distribution for well portion (C1 = 0.2 to C1 = 1.0)
is worked out in Table 2 and also shown in Fig. A4-3.
Fig. A4-4 : Hydrodynamic Force on Pier & Foundation
INDIAN HIGHWAYS
OCTOBER 2019
65
APPENDIX A-5 – ILLUSTRATION OF LIQUEFACTION OF SOIL
Notifications
66
INDIAN HIGHWAYS
OCTOBER 2019
Notifications
Notification No. 26
Amendment No.8/Irc:112/August, 2019 (effective from 31th October, 2019)
To
Irc:112-2011 “code of practice for concrete road bridges”
S. No.
Cl. No.
For
Read
1
3.1.2
(Page 5)
Design Working Life / Design Life
Assumed period for which a structure or part
of it is to be used for its intended purpose with
anticipated maintenance but without necessity of
major repair
2
5.8.1
(Page 25)
5.8.1 Design Service Life
For design service life of structures, reference may
be made to provisions of IRC:5. Unless otherwise
specifically classified by Owner, all structures
shall be designed for a useful service life of 100
years.
3.
6.2.2
(Page 30)
Note: (2)
The idealised bilinear diagram has sloping The idealised bilinear diagram has sloping
top
branch
Design Life
Assumed period for which a structure or part of it is
to be used for its intended purpose with anticipated
maintenance but without necessity of major repair
5.8.1 Design Life
For design life of structures, reference may be
made to provisions of IRC:5. Unless otherwise
specifically classified by Owner, all structures shall
be designed for a design life of 100 years.
top
joining
branch
joining
and, (εuk ; ft), where fyk ; ft, εuk are the minimum
values required by relevant IS Codes referred to in
Section 18.2.1 (Table 18.1). The factored idealised
design diagram is obtained by factoring
stress
values by,
that is by taking,
and, (εuk ; ft), where fyk ; ft, εuk are the minimum
values required by relevant IS Codes referred to in
Section 18.2.1 (Table 18.1). The factored idealised
design diagram is obtained by factoring stress
and limiting design strain to
and limiting design strain to
.
values by,
that is by taking,
.
For grades Fe 415D, Fe 500D & Fe 550D, εuk shall
be taken as 5% (max.) and for grades Fe 415S &
Fe 500S, εuk shall be taken as 8% (max.). For other
grades it shall be taken as 2.5% (max.).
Stainless steel reinforcement shall conform to
IS:16651:2017. The code covers requirements and
methods of test for high strength deformed stainless
steel bars/wires of the following strength grades for
use as concrete reinforcement:
(a) SS 500,
Note:The Indian Standard for Stainless Steel (b) SS 550,
reinforcement is under preparation. The British standard (c) SS 600, and
BS:6744:2001, which covers suitable stainless steels for (d) SS 650.
use as reinforcement may be referred.
4.
6.2.3.3
(Page 31)
Properties of stainless steel reinforcement shall
not be inferior to the carbon steel reinforcement of
corresponding strength class. For bond properties
reference should be made to the relevant code or
established on the basis of tests.
5.
6.3.5
(Page 34)
For strands, stress values shall be based on the For strands, stress values shall be based on the
nominal cross-sectional area given in Table 18.4. nominal cross-sectional area given in Table 18.4. The
The idealised design shape (A) is obtained by
idealised design shape (A) is obtained by factoring
,
, and taking design
factoring idealised bi-linear diagram by
and idealised bi-linear diagram by
taking design strain not greater than 0.9 εuk ,with strain not greater than εudwhich is equal to 0.9 εuk,
corresponding value of design stress.
with corresponding value of design stress. εudshall be
taken as 2% (max.), if more accurate values are not
available.
INDIAN HIGHWAYS
OCTOBER 2019
67
Notifications
6.
10.2.2.1
(Page 81)
In case of direct support [Fig. 10.1 (b)], a fan
like compression field exists. When structure is
subjected to predominantly uniformly distributed
loads, in area, confined by the beam end and the
steepest inclination (θmax= 45º) of the compression
field (generally within a distance equal to
effective depth from centre of support), no shear
reinforcement is required.
For concentrated loads the steepest inclination
may the taken as 26.5º (measured with respect
to vertical face of beam end, generally within a
distance of half the effective depth from centre of
support) and for loads within this distance no shear
reinforcement is required. It is however, necessary
to extend the shear reinforcement up to the support
from the section within this region 'A' (distance
d or half of d, as the case may be) and provide
tensile reinforcement for resisting the horizontal
components of these internal compressive forces
in addition to the steel provided for bending.
7.
10.2.3 (1)
(Page 84)
8.
10.3.3.2,
(Page 91)
9.
10.3.3.3 (5)
(Page 92)
In case of direct support, shear force VNS acting
at section d (effective depth) away from centre
of support, when the member is subjected
predominately uniformly distributed load and at
a distance d/2 away when member is subjected to
concreted loads – may be used for design of shear
reinforcement in the region between support to d
or support to d/2 as the case may be. For checking
crushing of concrete compression strut VNS shall be
taken at the centre of the support.
68
13.5
(Page 136)
For concentrated loads the steepest inclination may
the taken as 26.5º (measured with respect to vertical
face of beam end, generally within a distance of half
the effective depth from face of support) and for
loads within this distance no shear reinforcement
is required. It is however, necessary to extend the
shear reinforcement up to the support from the
section within this region ‘X1' (distance d or half
of d, as the case may be, see figure 10.1(b)) and
provide tensile reinforcement, adequately anchored
beyond bearing point, for resisting the horizontal
components of these internal compressive forces in
addition to the steel provided for bending.
In case of direct support, shear force VNS acting
at section d (effective depth) away from face
of support (or centre of bearing where flexible
bearings are used) when the member is subjected
predominantly uniformly distributed load and at
a distance d/2 away when member is subjected to
concentrated loads – may be used for design of shear
reinforcement in the region between support to d
or support to d/2 as the case may be. For checking
crushing of compression strut VNS shall be taken at
centre of support.
fywd is the design strength of web reinforcement to fywd is the design strength of web reinforcement to
resist shear = fyk / γm
resist shear (and torsion) = fyk / γmwhile the value
of fyk is limited to 500 MPa.
For non-grouted ducts, grouted plastic ducts and For non-grouted ducts and unbonded tendons the
nominal web thickness is:
unbonded tendons the nominal web thickness is:
Eq.10.15
bw,nom= bw - 1.2Σ Φ Eq.10.15
bw,nom= bw - 1.2Σ Φ The value 1.2 In Eq.10.15 is introduced to take
account of splitting of the concrete struts due
to transverse tension. If adequate transverse
reinforcement is provided this value may be
reduced to 1.0
10.
In case of direct support [Fig. 10.1 (b)], a fan
like compression field exists. When structure is
subjected to predominantly uniformly distributed
loads, in area, confined by the beam end and the
steepest inclination (θmax= 45º) of the compression
field (generally within a distance equal to effective
depth from face of support or centre of bearing
where flexible bearings are used), no shear
reinforcement is required.
End Block Design and Detailing
INDIAN HIGHWAYS
OCTOBER 2019
The value 1.2 In Eq.10.15 is introduced to take
account of splitting of the concrete struts due
to transverse tension. If adequate transverse
reinforcement is provided this value may be
reduced to 1.0
For grouted plastic ducts the nominal web thickness
is:
bw,nom = bw – 0.8 Σ Φ Eq.10.15a
Anchorage Block Design and Detailing
Notifications
11.
Pg No. 138
Additional clause
13.5.4 Intermediate Anchorages
13.5.4.1. General
Intermediate Anchorages are those post tensioned anchorages that are not
located at the end surface of a member or segment (see fig 13.2). They are
usually in the form of embedded anchors, blisters, ribs, or recess pockets.
In case of intermediate anchorages, tensile stresses may develop behind
the anchorages. These tensile stresses result from the compatibility of
deformations ahead of and behind the anchorage.The force of the tendon must
be carefully distributed to the flange/web by reinforcement in front as well as
behind the anchorage. For intermediate anchorages, the anchorage zone shall
be considered to extend for a distance not less than the transverse dimension
of the flange/ web to which it is anchored.
13.5.4.2. Intermediate anchorages shall not be used in regions where tensile
stress exceeding 1MPa is generated behind the anchor (upto 1.0 x depth
of section) from other actions under relevant SLS combination. Whenever
practical, blisters should be located in the corner between flange and webs or
shall be extended over the full flange width or web height to form a continuous
rib.
If isolated blisters are required to be used in the middle of a flange or web,
local shear, bending, and direct force effects, shall be adequately considered
in the design. For flange/web thickness up to 225 mm, an upper limit of force
equivalent to12 strands of 12.7 mm diameter shall be adhered to for tendons
anchored in intermediate blisters supported only by the flange or web.
13.5.4.3 Tie-back Reinforcement
Tie-back reinforcement is the one required to take care of the tensile stresses
indicated in 13.5.4.1. For this purpose bonded reinforcement shall be provided
to tie-back at least 25 percent of the unfactored intermediate anchorage
stressing force into the concrete section behind the anchorage. Stresses in this
bonded reinforcement shall not exceed 240 MPa. The anchorage force of the
tendon must be carefully distributed to the main structure by reinforcement.
If permanent compressive stresses are generated behind the anchor from
other actions, the amount of tie-back reinforcement may be reduced using the
following equation
Tia = 0.25 Ps - fcb Acb
where:
Tia = the tie-back tension force at the intermediate anchorage (N)
Ps = the maximum unfactored anchorage stressing force (N) transmitted to the
anchor plate
fcb = the unfactored dead load compressive stress in the regionbehind the
anchor (MPa)
Acb = the area of the continuing cross-section within the extensions of the
sides of the anchor plate.
or blister, i.e., the area of the blister or rib shall not be taken as part of the
cross-section (mm2)
The tie-back reinforcement shall be concentrated within one anchor plate
on either side of the tendon axis. It shall be fully anchored so that the yield
strength can be developed at a distance of one plate width or half the length
of the blister or rib ahead of the anchor as well as at the same distance
behind the anchor. The centroid of this reinforcement shall coincide with the
tendon axis, as far as possible. For blisters and ribs, the reinforcement shall
be placed in the continuing section near that face of the flange or web from
which the blister or rib is projecting.
INDIAN HIGHWAYS
OCTOBER 2019
69
Notifications
13.5.4.4 Blister and Rib Reinforcement
Reinforcement shall be provided throughout the blisters or ribs as required for shear friction, corbel
action, bursting forces, and deviation forces due to tendon curvature. This reinforcement shall extend
into the flange or web and be developed by standard hooks bent around transverse bars or equivalent.
Spacing shall not exceed the smallest of blister or rib height at anchor, blister width, or 150 mm,
whichever is less. Reinforcement shall be provided to resist local bending in blisters and ribs due to
eccentricity of the tendon force and to resist lateral bending in ribs due to tendon deviation forces. This
reinforcement is normally provided in the form of ties or U-stirrups, which encase the anchorage and
tie it effectively into the adjacent web and flange.
Reinforcement, as specified in earlier clauses of this Section shall be provided to resist tensile forces
due to transfer of the anchorage force from the blister or rib into the overall structure.
13.5.4.5 Precast Segmental Constructions
In the case of precast segmental structure, it is not feasible to provide continuing reinforcement over the
segment joints to take care of the stresses indicated in 13.5.4.1. In such cases, adequate compression,
behind the intermediate anchorages, through prestressing, shall be ensured to take care of these effects
in accordance with 15.3.2.1 (6).
12.
(Page 138)
Additional Figure
13.
Table 14.1
(Page 141)
Table 14.1 Classification of Service Environment Table 14.1 Classification of Service Environment
S.
Environment Exposure Condition
No.
(1) Moderate
Concrete dry or permanently
wet; concrete continuously under
water;
(2) Severe
Wet, rarely dry; humid (relative
humidity > 70 %), completely
submerged in sea water below
mid-tide level; concrete exposed
to coastal environment.
(3) Very severe
(4) Extreme
70
INDIAN HIGHWAYS
moderate humidity (relative
humidity
50-70
percent);
Concrete exposed to air-borne
chloride in marine environment;
freezing conditions while wet.
Cyclic wet and dry, concrete
exposed to tidal, splash and spray
zones in sea, concrete in direct
contact with aggressive sub-soil/
ground water, concrete in contact
with aggressive chemicals.
OCTOBER 2019
S.
Environment Exposure Condition
No.
(1) Moderate
Concrete dry or permanently
wet; concrete continuously under
water; low humidity (Relative
humidity
<50%);
humid
(Relative humidity >70 %)
(2) Severe
Wet, rarely dry; moderate
humidity (relative humidity ≥
50% and ≤70 %), completely
submerged in sea water below
mid-tide level; concrete exposed
to coastal environment.
(3) Very severe
Concrete exposed to air-borne
chloride in marine environment;
freezing conditions while wet.
(4) Extreme
Cyclic wet and dry, concrete
exposed to tidal, splash and spray
zones in sea, concrete in direct
contact with aggressive sub-soil/
ground water, concrete in contact
with aggressive chemicals.
Notifications
14.
16.7.1 (1)
(Page 185)
(1) Corbels may be designed by using strut and tie (1) Corbels may be designed by using strut and tie
model. The inclination of strut with respect to
model. The inclination of strut with respect to
axial direction of the member to which corbel
the “main” tie should lie between 45° and 68°.
is attached, should lie between 22o and 45o.
The strut shall be dimensioned such that the
concrete compression stress does not exceed
that given in clause 6.4.2.8. Horizontal forces,
HEd when applied in addition to the vertical load
FEd, will require additional reinforcement in the
tie. The effects of torsion, if any, have to be
catered to in accordance with clause 10.5.2.1
15.
16.7.1 (3),
Eq. 16.11
(Page 185)
As,link> 0.25 As,main
16.
16.7.1 (4),
(Page 185)
In corbels with ac> 0.5 hcand
(4)
FEd>VRd.c(Refer section 10), closed vertical stirrups
with area As.stirrupshall be provided in addition to
the main tension reinforcement as shown in Fig.
16.7(b), where:
As.stirrup ≥ 0.5 FEd / fyd
(4) In corbels where aclies between 0.5 hcand hc and
FEd>VRd.c(Refer clause 10.3.2 and 10.3.3), closed
vertical stirrups with area As.stirrupshall be provided
in addition to the main tension reinforcement and
the closed horizontal or inclined links, as shown in
Fig. 16.7(b), where:
As.stirrup ≥ 0.5 FEd / fyd
In addition check against crushing of strut shall be
made in accordance with Eq 10.5
17.
Additional
clauses (5)
to (7) to be
added in clause
16.7.1,
(Page 186)
New clause added
(5) If ac>hc the design shall be carried out as a
flexural member. The shear check shall be carried
out as per Eq 10.5 of 10.3.2 (5) for checking against
crushing of concrete as well as 10.3.3.3(7) and
10.3.3.3(8) for arriving at the shear reinforcement.
(6) The bearing area on a corbel shall not project
either beyond the straight portion of the main
tension bars or beyond the interior face of any
transverse anchor bar.
(7) In the case of corbels with varying depth, Fig
16.7(c), the depth at the outside edge of the bearing
area shall not be less than half the depth at the
face of the support. The favourable contributions
from inclined compression chord and tensile chord
(clause 10.2.3) shall not be considered.
As,link> 0.50 As,main(to be provided in upper twothird of the corbel depth)
INDIAN HIGHWAYS
OCTOBER 2019
71
Notifications
18.
17.1 (1)
(Page 192)
Ductile detailing shall be carried out for bridges Ductile detailing shall be carried out for the bridges
located in zones III, IV and V of seismic zone map located in Zones III, IV and V of the seismic Zone
of IRC:6.
map of IRC : 6 if they are designed for Response
reduction factor R > 1.0
19.
17.2.2 (3)
(Page198)
(3) The minimum amount of transverse ties shall be Change the clause no. from 17.2.2 (3) to 17.2.2.(2)
(c), with following revision :
determined as follows:
(c) The minimum amount of transverse ties shall be
determined as follows:
where
Al is the area of one tie leg, in mm2.
ST is the transverse distance between tie legs, in m; where
2
ΣAS is the sum of the areas of the longitudinal bars Al is the area of one tie leg, in mm .
S
i
s
the
spacing
of
the
legs
along
the
axis of the
2
L
restrained by the tie, in mm ;
member, in m;
fyt is the yield strength of the tie; and
ΣAS is the sum of the areas of the longitudinal bars
in outer layer restrained by tie at any one end,
fys is the yield strength of the longitudinal
in mm2;
reinforcement.
fyt
is the yield strength of the tie; and
fys is the yield strength of the longitudinal
reinforcement.
20.
New Addition Additional sub-clause added under 17.2.2.(2) (d)
to clause 17.2.2
(2) (d),
(Page 198)
(d) The steel As shall be determined for different
situations for At as follows:
As for determining Al = 0.5 As1 + As2 + 0.5 As3
As for determining Al1 = 0.5 As1 + As2
Al2 = As3
When Al is at any inclination to the transverse outer
tie, then the As shall be divided by the Sine of the
angle between the outer transverse tie and this tie,
e.g. in case Al is inclined at 45 degrees to the outer
tie, then As shall be divided by Sine 45, hence As =
√2 x (0.5 As1 + As2 + 0.5 As3)
72
INDIAN HIGHWAYS
OCTOBER 2019
Notifications
21.
17.2.2 (3),
(Pge 198)
New Clause to replace existing clause
(3) Along Circular section boundaries, restraining
of longitudinal bars should be achieved through
circular ties determined by:
fys
A1
1
2
x ρ D2 x
Eq. 17.9
=
fyt (mm /m)
l
12.8
SL
2
Al is the area of one circular tie, in mm .
SL is the spacing of the circular tie along the axis of
the member, in m;
ρ is the reinforcement ratio of the longitudinal
l
steel;
D is the Diameter of the Circular section in mm
fyt is the yield strength of the tie; and
fys is the yield strength of the longitudinal
reinforcement.
22.
17.2.3
(Page 198)
New clause to be added
Add after (3)
(4) The confinement steel and Buckling preventing
reinforcement shall not be added together.
(5) The Buckling prevention and confinement steel
may be provided through a set of hoops or single leg
cross ties. The hoops shall engage the longitudinal
bars only, while single leg ties shall engage both the
longitudinal bars and the transverse hoops in the
manner shown below at the 135 Degree bent hook.
Such ties need not comply with cover requirements
at such engagement locations.
23.
18.2.3.3
(Page 202)
Properties of stainless steel reinforcement
shall not be inferior to those of carbon steel
reinforcement of corresponding strength class.
For bond properties, the relevant code may
be referred or they may be established on the
basis of tests.
Stainless steel reinforcement shall conform to
IS:16651:2017.
Properties of stainless steel reinforcement shall not
be inferior to those of carbon steel reinforcement of
corresponding strength class.
Note : Till such time as the Indian Standard
for stainless steel reinforcement is available,
the British Standard BS:6744:2001, may be
referred.
INDIAN HIGHWAYS
OCTOBER 2019
73
Announcement
80th Annual Session to be held at Patna (Bihar)
from 12th to 15th December, 2019
On the invitation of Government of Bihar, the 80th Annual Session of the Indian Roads Congress will be
held at Patna (Bihar) from 12th to 15th December, 2019. The Invitation Booklet containing the Tentative
Programme, Registration Form, Accommodation Form etc. will be available on IRC website www.irc.nic.in
shortly. Accommodation is available on first come first serve basis. All members of IRC are invited to attend
the 80th Annual Session.
It is expected that more than 4000 Highway Engineers from all over the country and abroad will attend this
Session. During the Annual Session of IRC, there has been a practice for various firms/organizations to
make Technical Presentations on their products/technologies & case studies (with innovative construction
methods or technologies or having special problems requiring out of the box thinking and special solutions).
The presenters will get an opportunity to address a large gathering of highway professionals from Private
Sector as well as decision makers in the Govt. Sector. These presentations evoke lively interaction among
the participants.
A time slot of about 12-15 minutes is normally allocated for each Technical Presentation. Time is also
given for floor intervention. During such Technical Presentation Session, no other meetings will be held
parallel so as to ensure maximum attendance during the Technical Presentation Session. The stakeholders
are, therefore, requested to participate in the event and book slots at the earliest.
Interested Organizations may write to IRC conveying their willingness for participation and send the
topics of their Technical Presentation by E-mail: paper.irc-morth@gov.in / ad.irc-morth@gov.in or through
Speed Post alongwith a Demand Draft for Rs.75,000/- (Rupees Seventy Five Thousand only) drawn in
favour of Secretary General, Indian Roads Congress, New Delhi latest by 18th November, 2019 so that
necessary arrangements can be made by IRC.
For any enquiry about the 80th Annual Session like Registration, Membership & Technical Presentation etc.
please address to Secretary General, Indian Roads Congress Kama Koti Marg, Sector-6, R.K. Puram, New
Delhi-110022. For assistance the contact details are given as under:
Registration
Membership
Technical Presentation
Accommodation and Technical
Exhibition
Shri Naveen Tewari
Under Secretary
Phone +91 11 2617 1548
Mobile +91-9811099326
Email:
admn.irc-morth@gov.in
ircannualsession@gmail.com
Shri S.K. Chadha
Under Secretary
Phone + 91 2338 7140
Mobile +91 9899299959
Email: us1.irc-morth@gov.in
ircmembership1962@gmail.com
Shri Anil Sharma
Section Officer
Or
Ms. Shilp Shree
Assistant Director (Tech.)
Phone +91 2618 5273
Email:
paper.irc-morth@gov.in
ad.irc-morth@gov.in
Shri Umesh Kumar
Local Organising Secretary
(80th IRC Annual Session)
Managing Director,
Bihar Rajya Pul Nirman Nigam
Ltd.,
7, Sardar Patel Marg,
Patna - 800 015 (Bihar)
M: 09431821539
Email: 80ircpatna@gmail.com
74
INDIAN HIGHWAYS
OCTOBER 2019
REGISTRATION FORM
80th ANNUAL SESSION – PATNA (BIHAR) FROM 12TH TO 15TH DECEMBER, 2019
The Deputy Secretary (Admn.)
Indian Roads Congress,
Kama Koti Marg, Sector-6,
R.K. Puram
NEW DELHI - 110 022
Telephone No. : 011-26171548, 26105160
Email: admn.irc-morth@gov.in
ircannualsession@gmail.com
Website: www.irc.nic.in
USE BLOCK LETTER ONLY Tick (√) Wherever Applicable
IRC Membership No.__________________
(Mandatory)
Name :_________________________
Designation
:_________________________
Address
:_________________________
:_________________________
:_________________________
Pin Code
:_________________________
Age :_________________________
Election Rule No 9 (___)
Whether Official/Non-Official
Equivalent to :
Secy/ E-in-C/CE
[A]
SE
[B]
EE
[C]
AE
[D]
Telephone Nos. with (STD) Code
Office :__________________________
Residence
Fax
:__________________________
Mobile
E-mail :________________________________
:____________________
:____________________
Name of Spouse ( If accompanying)
Arrival
Date :
Time :
Mode :
If Official, Name of Sponsor &
Sanction Letter No. (copy enclosed) :
Age
Departure
Date :
Time :
Mode :
Want to avail Tour
[1]
[2]
[3]
Registration Fee :
Category of Delegates
A Delegates from India
1. Official Government Delegates
a) Senior (EE & above)
b) Junior (below EE)
2. Officials of Public and Private Sector
Undertakings/Companies, etc.
3. Individuals (Not nominated by the Government/Public
and Private Sector Undertakings/Companies, etc.)
4.Local Delegates (From the host State other than the official
delegates nominated by the host Govt./Dept./Organisations
5. Student Member
B. Delegates from Foreign Countries
Registration fee
Self
Spouse
Rs.7000.00
Rs.6000.00
Rs.7000.00
Rs.4000.00
Rs.4000.00
Rs.4000.00
Rs.4500.00
Rs.4000.00
Rs.4500.00
Rs.4000.00
Rs.2000.00
$150
-$100
Note : Members who are retired from service and age above 60 are entitled for 25% rebate on above rates of registration
fee. This rebate will not be admissible to the spouse of the retired Member. Spouses of the delegates will also have to be
registered on payment of the requisite registration fee
INDIAN HIGHWAYS
OCTOBER 2019
75
REGISTRATION FORM
Payment Mode :
Demand
draft/cheque
No.___________________________
Dated______________
___issued
by__________________________drawn in favour of Secretary General, IRC payable at New Delhi amounting
Rs. __________________as Registration fee is enclosed
Own Arrangements : Yes [Y]
No [N]
Address :­­___________________________________________________________________
­­___________________________________________________________________
­­___________________________________________________________________
Accommodation as Govt. Officer : Single (S) / Double (D)
_____________Days from______________to_____________ ___ __________________
Accommodation for delegates (Paying Full) :
Single(S)/ Double (D)
Hotel Name :_________________
_______________Days from______________to_______________ _____ _____________
(Payment for accommodation charges should be made to LOS at Patna
Date____________________________ Signatures_________________________________
For Office Use Only
Receipt No
: __________________________________
Amount (Rs.)
: ___________________­_______________
76
INDIAN HIGHWAYS
OCTOBER 2019
Dated : ________________
ACCOMMODATION FORM
80th ANNUAL SESSION, patna (BIHAR) from 12th to 15th december 2019
(Please Return before 25th November 2019)
Shri Umesh Kumar
(Local Organising Secretary, 80th Annual Session)
Managing Director,
Bihar Rajya Pul Nirman Nigam Ltd.
7, Sardar Patel Marg
Patna-800015 (Bihar)
USE BLOCK LETTERS ONLY. Tick (√) Wherever Applicable
Mobile No.
E-mail
Website
IRC Membership No. __________________
(Mandatory)
Name
: _________________________
Designation : _________________________
Address
: _________________________
: _________________________
: _________________________
Pin Code
: _________________________
Age
: _________________________
Telephone Nos. with (STD) Code
Office
: _________________________
Fax
: _________________________
E-mail
: _________________________
Name of Spouse (If accompanying)
:
:
:
Whether Official/Non-Official
Equivalent to :
Secy/E-in-C/CE
[A]
SE
[B]
EE
[C]
AE
[D]
Basic Pay (Rs.) :
Total Emoluments Rs. :
Residence
Mobile
: ____________________
: ____________________
Age
Veg [V]/Non-veg [N]
Arrival Date
Mode
Flight No.
Departure Date
Air/Train/Bus/Car
Time
Date
Airport :
Train Name
+91 94318 21539
80ircpatna@gmail.com
www.80ircpatna.in
Mode
Air/Train/Bus/Car
Flight No.
Time
Date
Time
Date
Airport :
Time
Class
Date
Station
Train Name
Class
Station
Bus
Time:
Date:
Bus
Time:
Date:
Car
Time:
Date:
Car
Time:
Date:
Own Arrangements :
Yes [Y]
No [N]
Address :
__________________________________________________
__________________________________________________
__________________________________________________
INDIAN HIGHWAYS
OCTOBER 2019
77
ACCOMMODATION FORM
Accommodation as Govt. Officer: Single [S]/Double[D]
S.No.
DESIGNATION
For Self
For Spouse
1.
Secretaries/Engineers-in-Chief
Rs.10000
Rs.3500
2.
Chief Engineers/Addl.C.Es
Rs.9500
Rs.3500
3.
Superintending Engineers
Rs.8500
Rs.3500
4.
Executive Engineers
Rs.7000
Rs.3000
5.
AEEs/Asst. Engineers/J.Es
Rs.6000
Rs.3000
6.
Single Delegates of DE/JE category with availing common
sharing facility
Rs.500/Bed
--
7.
Delegates from Foreign Countries
$250
$125
______________________Days from____________________to__________________________
Accommodation for delegates
(Paying Full)
Single (S)/Double (D)
Hotel Name : _____________________________@ Rs.____________________________
Days from___________________________to___________________December, 2019
For online payment and booking of Accommodation, visit www.80ircpatna.in
Date : ____________________
Signature : ________________________
Note : Draw Demand Draft in favour of "Local Organising Secretary, 80th Annual Session, IRC payable at Patna for
accommodation and tours. Accommodation would be confirmed only on receipt of payment in advance.
78
INDIAN HIGHWAYS
OCTOBER 2019
ANNOUNCEMENT
REGIONAL WORKSHOP ON
“QUALITY CONTROL, NEW MATERIALS AND TECHNIQUES IN
ROAD SECTOR”
TO BE HELD AT IIT ROORKEE ON 8TH & 9TH NOVEMBER, 2019
The Indian Roads Congress (IRC) in association with Indian Institute of Technology, Roorkee is organizing a Regional
Workshop on “Quality Control, New Materials and Techniques in Road Sector” on 8th & 9th November, 2019 for the
benefit of engineers from Northern Region of India at IIT Roorkee (Uttarakhand).
The purpose of organizing this two days Workshop is imparting technical knowledge about latest technology on Quality
Control, New Materials, Techniques, Machinery and modern trend amongst Highways Engineers/Professionals. This
two-day Workshop will be benefitted to the Engineers/professionals from the State of Uttarakhand, and its adjacent
states; Uttar Pradesh, Punjab, Haryana, Himachal Pradesh, J&K, Delhi and officers from MoRT&H, NHAI, NRIDA,
including local bodies and representatives of contractors & consulting firms.
The main themes to be covered in the Technical Sessions of this two days Workshop are: Rheology of Bitumen,
Soil Stabilization (Modern Techniques), Bitumen Modifiers, Warm Mix Asphalt, Cold Mix, RAP Materials, Flexible
& Rigid Pavements and Materials, Cement Treated Base, Quality control, New Pavement Material and Techniques.
Venue:
The Venue for the Workshop is Dr. O.P. Jain Auditorium, Department of Civil Engineering, IIT Roorkee,
Limited Accommodation available at guest houses at IIT Roorkee on payment basis.
Registration:
The registration fee for the Workshop per delegate:
For IRC Members: Rs.6000/For Non Members: Rs.7000/For Students:
Rs.3000/Payment for Registration fee can be made through Cash at IRC Delhi office or by Demand Draft/Cheque drawn in favour of Secretary
General, Indian Roads Congress, payable at New Delhi or also online mode , NEET/RTGS payments as per details given below:
Account Holder Name: Indian Roads Congress;
Bank: Syndicate Bank, ,R.K. Puram, branch New Delhi;
Bank A/c No.90092140000352; IFSC Code: SYNB0009009;
Members of IRC from the concerned States may pursue with their authorities for nomination for participating in this
Workshop.
For further information in this regard, please contact:
At New Delhi
At Roorkee:
Shri Rahul V. Patil
Deputy Director (Tech.)
Indian Roads Congress,
IRC Bhawan, Kama Koti Marg,
Sector-6, R.K. Puram,
New Delhi – 110 022
Mobile: 093128 49826
e-mail:irchrb@gmail.com
Dr. G.D. Ransinchung R.N.,
Associate Professor & Faculty Adviser (SSO)
& Students Club,
O.C.M. Tech., Transportation Engineering
Group,
Civil Engineering Department
IIT Roorkee, Roorkee, (Uttrakhand)
Mobile: 94589 47088
e-mail : gdranfce@iitr.ernet.in
INDIAN HIGHWAYS
OCTOBER 2019
79
REGISTRATION FORM
Regional Workshop on
“Quality Control New Materials and
Techniques in Road Sector”
Indian Roads Congress
IIT, Roorkee
The Secretary General Please return before 20th October, 2019
Venue: Dr. O.P. Jain Auditorium,
IIT Roorkee, Uttarakhand
Indian Roads Congress
Kama Koti Marg, Sector 6,
R.K. Puram, New Delhi-110 02 Date:
Tel. (011) 2618 5273
e-mail: irchrb@gmail.com; secygen.irc@gov.in 8TH & 9TH November, 2019
(Friday and Saturday)
1.
IRC Membership No. ________________________
2.
Name: __________________________________________________________________________________
3.
Designation: _____________________________________________________________________________
4.
Mailing Address: _________________________________________________________________________
________________________________________________________________________________________
5.
Telephone:
STD Code: _______ Office: _____________
Residence: _________________________
Mobile: ___________________ e-mail ID: _______________________________________
6.
Nominated/Sponsored by: ___________________________________________________________________
7.
Registration Fee (without accommodation facility)
For IRC Members: Rs.6000/For Non Members: Rs.7000/For Students:
Rs.3000/Mode of Payment
(a)
Demand Draft No. __________________ Date _______________ for Rs. ____________
(b)
Online Transaction No. ______________ Date________________ for Rs.____________
Signature
Account Holder Name: Indian Roads Congress;
Bank: Syndicate Bank, ,R.K. Puram, branch New Delhi;
Bank A/c No.90092140000352; IFSC Code: SYNB0009009;
Note : Demand Draft is to be drawn in favour of the Secretary General, Indian Roads Congress, payable at New
Delhi.
80
INDIAN HIGHWAYS
OCTOBER 2019
Notifications
ADVERTISEMENT
INDIAN HIGHWAYS
OCTOBER 2019
81
ADVERTISEMENT
Notifications
82
INDIAN HIGHWAYS
OCTOBER 2019
Delhi Postal Registration No
uNDeR ‘u’ NumbeR
At Lodi Road, PSO on dated 28-29.09.2019
ISSN 0376-7256 Newspaper Regd. No. 25597/73
INDIAN HIgHwAyS
`20/-
DL-Sw-17/4194/19-21
u(Sw)-12/2019-2021
LICeNCe tO POSt
wItHOut PRePAymeNt
PubLISHeD ON 23 SePtembeR, 2019
ADvANCe mONtH, OCtObeR, 2019
OCTOBER, 2019
IndIan HIgHways
volume : 47 Number : 10 total Pages : 84
Pasighat-Pangin Section NH-229 in Arunachal Pradesh
edited and Published by Shri S.K. Nirmal, Secretary general, Indian Roads Congress, IRC HQ, Sector-6, R.K. Puram,
Kama Koti marg, New Delhi - 110 022. Printed by Shri S.K. Nirmal on behalf of the Indian Roads Congress
at m/s. Aravali Printers & Publishers Pvt. Ltd.
https://www.irc.nic.in