and
Aga Khan Planning and Building Services, Pakistan
Pakistan Building Code – Seismic Provisions 2007
September 9, 2013
Prof. Sarosh H Lodi
Continuing Professional Development
Short Course Series
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DEDICATED
TO
THOUSANDS OF CHILDREN, WOMEN AND MEN
WHO
LOST THEIR LIVES
IN
THE 8th OCTOBER 2005 EARTHQUAKE
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CHAPTER 1:
SCOPE
CHAPTER 2:
SEISMIC HAZARD
CHAPTER 3:
SITE CONSIDERATIONS
CHAPTER 4:
SOILS AND FOUNDATIONS
CHAPTER 5:
STRUCTURAL DESIGN REQUIREMENTS
DIVISION-I
General Design Requirements
DIVISION-II
Snow Loads
DIVISION-III
Wind Design
DIVISION-IV
Earthquake Design
DIVISION-V
Soil Profile Types
CHAPTER 6:
STRUCTURAL TESTS AND INSPECTIONS
CHAPTER 7:
REINFORCED CONCRETE
CHAPTER 8:
STRUCTURAL STEEL
PART I. Structural Steel Buildings
PART II. Composite Structural Steel and Reinforced Concrete Buildings
CHAPTER 9:
MASONRY
CHAPTER 10: TIMBER
CHAPTER 11:
ARCHITECTURAL ELEMENTS
CHAPTER 12: MECHANICAL & ELECTRICAL SYSTEMS
APPENDIX-A
BACKGROUND FOR SEISMIC ZONING MAP
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CHAPTER 1:
SCOPE
Objective and General Principles
The objective of the criteria and earthquake provisions described in this
code is to prescribe the minimum requirements for the earthquake design
and construction of buildings and building-like structures and/or their
components subjected to earthquake ground motions.
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Scope
• Requirements of these provisions shall be applicable to reinforced
concrete buildings, steel buildings, building-like structures, masonry and
timber buildings.
• In addition to the buildings and building-like structures, non-building
structures permitted to be designed in accordance with the requirements
of these provisions are limited to those specified in Chapter 5.
• In this context bridges, dams, harbour structures, tunnels, pipelines,
power transmission lines, power generation plants including hydel,
thermal and nuclear power plants, gas storage facilities, special defence
installations, underground structures and other structures designed with
analysis and safety requirements that are different than those for buildings
are outside the scope of this code.
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• Requirements of these provisions shall not be applied to the
buildings equipped with special system and equipment between
foundation and soil for the purpose of isolation of building structural
system from the earthquake motion, and to the buildings
incorporating other active or passive control systems.
• Requirements to be applied to structures which are outside the
scope of these provisions, shall be specifically determined by the
Departments/Autonomous
Organizations
supervising
the
construction and such structures shall be designed to those
provisions until their specifications are prepared by the Competent
Authority.
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CHAPTER 2:
SEISMIC HAZARD
This Chapter defines the minimum seismic hazard that has to be
considered for the design of buildings
CHAPTER 3:
SITE CONSIDERATIONS
The selection of suitable building sites shall be carried out based upon their
geology/ stratigraphy, distance from the causative fault, the liquefaction
potential of site, earthquake induced land sliding, and presence of sensitive
clays any other relevant geotechnical aspects, as provided in this chapter.
CHAPTER 4:
SOILS AND FOUNDATIONS
Determination of soil conditions of buildings to be constructed in seismic
zones, design of reinforced concrete, structural steel, timber and masonry
building foundations and soil retaining structures shall be performed, along
with the applicable codes and standards in relevant areas, primarily in
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accordance with the rules and requirements of this section.
CHAPTER 5:
STRUCTURAL DESIGN REQUIREMENTS
This chapter prescribes general design requirements applicable to all
structures regulated by this code.
DIVISION-I
DIVISION-II
DIVISION-III
DIVISION-IV
DIVISION-V
CHAPTER 6:
General Design Requirements
Snow Loads
Wind Design
Earthquake Design
Soil Profile Types
STRUCTURAL TESTS AND INSPECTIONS
The owner or the engineer or the architect incharge acting as the owner’s
agent shall employ one or more special inspectors who shall provide
inspections during construction on the types of work listed under Section
6.1.5.
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CHAPTER 7:
REINFORCED CONCRETE
This Chapter contains special requirements for design and construction of cast-inplace reinforced concrete members of a structure for which the design forces, related
to earthquake motions, have been determined on the basis of energy dissipation in the
nonlinear range of response as specified in Chapter 5.
CHAPTER 8:
STRUCTURAL STEEL
The Seismic Provisions for Structural Steel Buildings, hereinafter referred to as these
Provisions, shall govern the design, fabrication and erection of structural steel
members and connections in the seismic load resisting systems (SLRS) and splices in
columns that are not part of the SLRS, in buildings and other structures, where other
structures are defined as those structures designed, fabricated and erected in a
manner similar to buildings, with building-like vertical and lateral load-resistingelements. These Provisions shall apply when the seismic response modification
coefficient, R, (as specified in the Chapter 5, Table 5-N) is taken greater than 3,
regardless of the seismic design category. When the seismic response modification
coefficient, R, is taken as 3 or less, the structure is not required to satisfy these
Provisions, unless specifically required by the applicable building code.
PART I. Structural Steel Buildings
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PART II. Composite Structural Steel and Reinforced Concrete Buildings
CHAPTER 9:
MASONRY
This chapter covers the structural design of un-reinforced, reinforced and confined
load bearing and non-load bearing walls, constructed with masonry units permitted
in accordance with this chapter. The provisions of this section do not apply to walls
constructed in mud mortars.
CHAPTER 10:
TIMBER
Design of timber buildings or building-like structures constructed in seismic areas
with load-bearing walls carrying both vertical and lateral loads as well as floors
made of timber skeleton shall be performed primarily in accordance with the
requirements of this Chapter.
CHAPTER 11:
ARCHITECTURAL ELEMENTS
CHAPTER 12:
MECHANICAL & ELECTRICAL SYSTEMS
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APPENDIX – A
BACKGROUND FOR SEISMIC ZONING MAP
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OVERVIEW
Being located close to the collision boundary of the Indian
and Eurasian plates, Pakistan lies in a seismically active
zone. Owing to high population density near seismically
active areas, it is imperative that buildings should withstand
the seismic hazard to which these may be exposed during
their life time.
Seismic Zoning map is prepared on a rigorous exercise based
on compilation of geological, tectonic and seismicity data
from Pakistan and its immediate surroundings. Only a brief
account of salient seismotectonic features, seismicity and
methodology adopted for seismic hazard zonation are
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mentioned here.
Major Faults of Pakistan
Pakistan is characterized by extensive zones of moderate to high
seismicity, induced by the regional collisional tectonics associated
with Indian and Eurasian plates and resulting in manifestation of great
Himalayan and associated mountain ranges.
The geographic domain of Pakistan comprises a network of active
seismotectonic defined five broad seismotectonic zones
1)
2)
3)
4)
5)
Himalayan seismotectonic zone in the north,
Suleman-Kirthar thurst-fold belt,
Chaman-Ornach Nal Trasform Fault Zone,
Makran Subduction Zone in the west, and
Run of Kutch Seismotectonic Zone in the southeast.
The Pamir-Hinukush Seismic Zone straddles across Afghanistan and
Tajikistan outside Pakistan but in close vicinity of the NW Pakistan
comprising District Chitral.
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Major Faults of Pakistan
Major active faults of Pakistan and surrounding areas that strongly influence
the seismic hazard are listed below:
1.
2.
3.
4.
Main Karakoram Thrust
Raikot Fault
Panjal-Khairabad Thrust
Riasi Thrust
5.
6.
7.
8.
9.
Salt Range Thrust
Bannu Fault
Chaman Transform Fault
Quetta-Chiltan Fault
Pab Fault
10. Allah Bund Fault
11. Hoshab Fault
12. Makran Coastal Fault
13. Main Mantle Thrust
14. Main Boundary Thrust
15. Himalayan Frontal Thrust
16. Jhelum Fault
17. Kalabagh Fault
18. Kurram Fault
19. Ornach-Nal Transform Fault
20. Kirthar Fault
21. Kutch Mainland Fault
22. Nagar Parkar Fault
23. Nai Rud Fault
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SEMINAR
ACI CODE
Tirich Mir-Misgar F.
Fault Map of
Pakistan
MKT
Indus-Kohistan F
Muzafarabad T.
Kurram T.
MMT
Panjal T.
SRT
MBT
Waziristan T.
Chaman F.
Kalabagh F.
Jhelum F.
Raisi T.
Sulaiman Frontal T.
Ghazaband T.
Hoshab F.
Kirthar F.
Hoshab F.
Pab F.
Rann of Kuchh F.
MakranSubduction Zone
OrnachNal F.
After NESPAK 2006
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Seismicity
The information about earthquakes in this region have been used
based upon earthquake data from regional data catalogues
compiled by
•
•
•
International Seismological Centre (ISC)
National Earthquake Information Centre (NEIC) of USGS, and
from earthquakes recorded by local networks of Pakistan
Meteorological
Department,
Pakistan
Atomic
Energy
Commission (PAEC) and Water & Power Development Authority.
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Seismic Hazard Evaluation Procedure
Probabilistic Seismic Hazard Assessment (PSHA) procedure was
used for seismic hazard analysis of Pakistan - as per international
practice and guidelines for seismic hazard evaluation and seismic
hazard mapping for Building Codes.
1.
PSHA Methodology
Seismic activity of seismic source is specified by a recurrence
relationship, defining the cumulative number of events per year
versus the magnitude.
Principle developed by Cornell (1968) is used to evaluate probability
of peak ground acceleration due to an earthquake.
This approach combines the probability of exceedance of the
earthquake size and probability on the distance from the epicenter
to the site.
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2.
Source Modeling
For seismic sources entire area of Pakistan was divided into seventeen
area source zones based on their homogeneous tectonic and seismic
characteristics, keeping in view the geology, tectonics and seismicity of
each area source zone.
Eight area seismic source zones in the northern part of Pakistan
Hindukush, Pamir, Kohistan, Hazara, Himalayas, Salt Range-Potwar,
Bannu and Punjab.
Nine area source zones in southern part
Suleiman, Sibbi, Kirthar, Kurram-Chaman, Indus plateform, Rann of
Kutch, Cholistan-Thar desert, Chagai and Makran
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3.
Earthquake Recurrence Model
Equations like
N (m) = f (m, t)
Log N(m) = a – b m
(1)
(2)
were used with a composite list of earthquakes for areas in and around Pakistan
which provided the necessary database for the computation of values for each
area source zone.
For data to be used in seismic hazard analysis, all the magnitudes were converted
to moment magnitude (MW) by the following equations.
MW = 0.67 MS + 2.07
MW = 0.99 MS + 0.08
MW = 0.85 mb + 1.03
for 3.0< MS < 6.1
for 6.2< MS < 8.2
for 3.5< mb < 6.2
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4.
Maximum Magnitude
To each area source zone, a maximum magnitude potential was assigned
based on the maximum observed seismicity in the historical seismic
record or enhancing by 0.5 magnitude the maximum observed magnitude
in the instrumental seismic record for that area seismic source zone.
5.
Attenuation Equations
Due to lack of sufficient strong–motion data covering a larger range of
magnitudes and distances, attenuation relationships for the South
Asian Region could not be developed so far.
For probabilistic hazard analysis, the attenuation equation of Boore et
al. (1997) along with three other equations developed during 1996 to
2004 have been used with equal weightage (25%) to each equation.
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5.
Results of PSHA
The probabilistic hazard analysis was carried out by using EZ-FRISK
software developed by Risk Engineering Inc. of Colorado, USA.
As the purpose of the PSHA was to develop seismic hazard contour
map, Gridded- Multisite module of EZ-FRISK software was used.
The required parameters for all the fourteen area seismic source
zones and twenty eight fault seismic sources were fed to the software.
The results of the hazard analysis obtained at each grid point are
presented in the form of total hazard from all the seismic sources
modeled The ground motion associated with 10% probability of
exceedance in 50 years (475 years return period) was calculated at
each grid point. From the results obtained at 0.1 degree interval,
contours of Peak Ground Acceleration (PGA) values were plotted
through GIS software.
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RESULTS OF PSHA PEAK GROUND
ACCELERATION
VALUES
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6.
Seismic Zoning
On the basis of PGA values obtained through PSHA, Pakistan was
divided into five seismic zones in line with UBC97. The boundaries of
these zones are defined on the following basis:
Zone 1
0.05 to 0.08g
Zone 2A
0.08 to 0.16g
Zone 2B
0.16 to 0.24g
Zone 3
0.24 to 0.32g
Zone 4
> 0.32g
The seismic zoning map of Pakistan developed on this basis is shown
in Fig. 2.1. Each structure shall be assigned a seismic zone factor Z in
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accordance with this map or Table 5-I given in Chapter 5 of the Code.
SEISMIC ZONING MAP OF PAKISTAN
Zone 1
0.05 to 0.08g
Zone 2A 0.08 to 0.16g
Zone 2B 0.16 to 0.24g
Zone 3
0.24 to 0.32g
Zone 4
> 0.32g
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SEMINAR
ACI CODE
???
HYDERABAD
BUILDING AND
TOWN PLANNING
REGULATIONS2007
KBCA
DHA
FC
CC
KPT 33
RC Buildings
Brick Masonry
Block Masonry
Adobe Masonry
Stone Masonry
Wood Reinforced Structures
Others
Summary
of Building
Building Typology
Typology
RC
M1
M2
M3
M4
M5
OO
reinforced concrete moment
resisting frame buildings
Brick Masonry
Block Masonry
Stone Masonry
Adobe Masonry
Wood Reinforced Masonry
Others
Percentage of Building Types In Pakistan
3.30%
5.27%
5.19%
1.62%
Brick Masonry
7.64%
14.60%
Adobe Masonry
RC Buildings
62.38%
Wood/Bamboo Reincorced
Stone Masonry
Block Masonry
Others
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THANK YOU
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