A
PROJECT REPORT ON
ANALYSIS AND DESIGN
OF
RECTANGULAR WATER TANK BY USING STAAD Pro
Major project report submitted in partial fulfillment for the academic requirements
For the award of
BACHELOR OF TECHNOLOGY
IN
CIVIL ENGINEERING
AKULA MADHU
17TP1A0104
BANOTH CHANDU
17TP1A0112
GONDHI NISHANTH KUMAR REDDY
17TP1A0129
KALAKONDA SRUTHI
17TP1A0136
Under the esteemed guidance of
B.Divya
Assistant.prof
Department of Civil Engineering
Siddhartha Institute of Engineering and Technology
Vinobhanagar, Ibrahimpatnam, RR Dist
2020-21
i
DEPARTMENT OF CIVIL ENGINEERING
SIDDHARTHA INSTITUTE OF ENGINEERING AND TECHNOLOGY
Vinobhanagar, ibrahimpatnam, RR Dist.
CERTIFICATE
This is to certify that the Major Project entitled “ANALYSIS AND DESIGN OF
RECTANGULAR WATER TANK BY USING STAAD Pro” being submitted by
AKULA MADHU 17TP1A0104 , BANOTH CHANDU 17TP1A0112 , GONDHI
NISHANTH KUMAR REDDY 17TP1A0129, KALAKONDA SRUTHI
17TP1A0136 , in partial fulfillment for the academic requirements for the award of bachelor of
technology Affiliated to JNTU, HYD.
INTERNAL GUIDE
HEAD OF THE DEPARTMENT
B.Divya
Y.Naveen kumar
Assistant prof.
Associate prof.
EXTERNAL EXAMINER
PRINCIPAL
SIDDHARTHA INSTITUTE OF ENGG. &TECH
ii
ACKNOWLEDGEMENT
We wish to express my sincere thanks to Dr.D. Pradeep Kumar , Secretary, Siddhartha Institute of
Engineering &Technology and all the Directors, Siddhartha Institute of Engineering &Technology,
for providing me with all the necessary facilities and their support.
We also wish to thank Dr.V.Bhagya raju Principal, Siddhartha Institute of Engineering
&Technology for his support and guidance
We place on record, my sincere thanks to, Y.Naveen kumar Associate Professor and Head of Civil
Engineering Department for his whole hearted co-operation, providing excellent lab facility, constant
encouragement and unfailing inspiration.
We also thank my internal guide, Mrs. B.Divya Assistant Professor, Civil Engineering Department and
extremely grateful and indebted for her sincere support and encouragement extended for me in
completion of this major project.
We take this opportunity to record my sincere thanks to the other faculty of the department of civil
engineering for giving timely suggestions during the progress of the major project work.
Finally, We would like to thank my parents who have always encouraged me to do my best.
iii
DECLARATION
We hereby declare that We carried out the project work presented in this report in partial fulfillment of
for the award of the degree of Bachelor of Technology during the academic year 2020-21; in the
Department of Civil Engineering, Siddhartha Institutions Technical Campus affiliated to Jawaharlal
Nehru Technological University Hyderabad,
We solemnly declare that to the best of our knowledge; no part of this report has been submitted here or
elsewhere in a previous application for award of a degree. All sources of knowledge used have been
duly acknowledged.
Akula Madhu
17TP1A0104
Banoth Chandu
17TP1A0112
Gondhi Nishanth Kumar Reddy
17TP1A0129
Kalakonda Sruthi
17TP1A0136
iv
ABSTRACT
Storage reservoirs and overhead tank are used to store water, liquid petroleum, petroleum
products and similar liquids. The force analysis of the reservoirs or tanks is about the same irrespective
of the chemical nature of the product. All tanks are designed as crack free structures to eliminate any
leakage. It is located in nagarkarnool.
This project gives in brief, the theory behind the design of liquid retaining structure (circular
water tank with flexible and rigid base and rectangular water tank) using working stress method. This
report also includes computer subroutines to analyze and design circular water tank with flexible and
rigid base and rectangular underground water tank. The program has been written as Macros in Microsoft
Excel using Visual Basic programming language. In the end, the programs are validated with the results
of manual calculation given in Concrete Structure book.
This project explains the applications of the established equations for the different cases as
mentioned above through several numerical problems. The problems are solved in step-by-step mostly
utilizing the equations. However, a few problems are solved from the first principle for better
understanding. Understanding the solutions of illustrative examples and solutions of the practice and
test problems will give confidence in applying the appropriate equations and selecting the permissible
stresses for analyzing and designing tension structures or members using working stress method and
following the stipulations of Indian Standard Codes.
KEYWORDS:
➢ IS: 1893 -2002 (PART-2) Liquid Retaining Tanks
➢ STAAD Pro V8i
v
INDEX PAGE
Title
P g .No.
PROJECT TITLE
Ⅰ
CERTIFICATE
Ⅱ
ACKNOWLEDGEMENT
Ⅲ
DECLARATION
Ⅳ
ABSTRACT
Ⅴ
CONTENTS
Ⅵ-ⅷ
LIST OF FIGURES
ⅸ
LIST OF TABLES
ⅹ
Chapter -1.0 INTRODUCTION
1-4
1.1 TYPES OF WATER TANKS
1
1.2 UNDERGROUND WATER TANK
2
1.3 TANKS RESETING ON GROUND
2
1.4 RECTANGULAR TANKS
3
1.5 SCOPE OF THE PROJECT
3
1.6 SOURCES OF WATER SUPPLY
3
1.7 Water quantity estimation
4
1.8 Objectives
4
CHAPTER- 2.0 LITERATURE REVIEW
5-7
2.1.0 LITERATURE REVIEW
5
2.1.1 MAINAK GHOSAL GHOSAL
5
2.1.2 L.P. SRIVASTAVA & AKSHIT LAMBA
5
2.1.3 ISSAR KAPADIA, PURAV PATEL, NILESH DHOLIYA
6
2.1.4 RAJKUMAR, SHIVARAJ AND MANGALGI
6
2.1.5 HASAN JASIM MOHAMMED
6
2.1.6 K.VIJAY PURI AND SHAMSHEER PRAKASH
7
2.1.7 PANDEY ETAL
7
CHAPTER -3.0 SOFTWARES
8
vi
3.1.0 GENERAL
8
3.1.1 SOME OF THE IMPORTANTOF STAAD .Pro
8
3.1.2PHYSICAL MODELLING
8
3.1.3 ANALYTICAL MODELLING
9
3.1.4 STEEL AUTODRAFTER
9
3..5 ADVACED SLAB DESIGN
9
3.1.6 ADVANCED CONCRETED DESIGN
9
3.2 ADVANTAGES OF STAADPRO SOFTWARE
9
3.3 KEYPOINTS
10
CHAPTER-4.0 METHODOLOGY
4.1DESIGN REQUIREMENT OF RECTANGULAR TANK
11
4.2 DESIGN REQUIREMENT OF CONCRETE
11
4.3 JOINTS IN LIQUID RETAINING STRUCTURES
13
4.3.1 MOVEMENT JOINTS
13
4.3.2CONTRACTION JOINTS
15
4.3.3 TEMPORARY JOINTS
15
4.3.4 SPACING JOINTS
16
4.4 GENERAL DESIGN REQUIREMENTS
17
4.4.1 PLAIN CONCRETE STRUCTURES
17
4.4.2 PERMISSIBLE STRESSES IN CONCRETE
17
4.4.3PERMISSIBLE STRESSES IN STEEL
18
4.4.4 STRESSES DUE TO DRYING SHRINKAGE
18
4.4.5 FLOORS
19
4.4.6 WALLS
20
4.4.7 ROOFS
22
4.4.8 MINIMUM REINFORCEMET
23
4.4.9 MINIMUM COVER TO REINFORCEMENT
24
4.5 FLEXIBLE BASE CIRCULAR TANK
25
4.6 RIGID BASE CIRCULAR TANK
26
4.7 RECTANGULAR WATEER TANK
28
vii
4.8 STATEMENT OF THE PROJECT
30
CHAPTER-5.0 RESULTS AND DISCUSSION
5.1 DESIGN OF RECTANGULAR WATER TANK RESTING ON THE GROUND
32
TANK RESTING ON THE GROUND
CHAPTER -6 CONCLUSION
47
CHAPTER- 7REFERENCES
48
viii
LIST OF FIGURES
Figure No.
4.1
Title
Page No.
plan view of water tank
13
4.2.(a) contraction joint with deliberate discontinuity
13
4.2(b) contraction joint with complete partial contraction
13
4.2(c) expansion joint
14
4.2(d)
sliding joint
15
4.3
contraction joint
15
4.4(a) Temporary open joint with prepared joint surface
16
4.4(b) Temporary open joint with joint sealing compound
16
4.4(c) Temporary open joint with mortar filling
16
4.5
Axial load application on wall of water tank
20
4.6
Load application of water tank
22
4.7
plate load on water tank
23
4.8
plate stresses on water tank
29
4.9
rectangular water tank
30
4.10
sectional view of rectangular water tank
30
4.11
3D Rendering view of rectangular water tank
31
ix
LIST OF TABLES
Table No.
1
Topic
Permissible Concrete Stresses
x
Page No.
18
1.0 INTRODUCTION
CHAPTER- 1
Storage reservoirs and overhead tank are used to store water, liquid petroleum, petroleum
products and similar liquids. The force analysis of the reservoirs or tanks is about the same irrespective
of the chemical nature of the product. All tanks are designed as crack free structures to eliminate any
leakage. Water or raw petroleum retaining slab and walls can be of reinforced concrete with adequate
cover to the reinforcement. Water and petroleum and react with concrete and, therefore, no special
treatment to the surface is required. Industrial wastes can also be collected and processed in concrete
tanks with few exceptions. The petroleum product such as petrol, diesel oil, etc. are likely to leak through
the concrete walls, therefore such tanks need special membranes to prevent leakage. Reservoir is a
common term applied to liquid storage structure and it can be below or above the ground level.
Reservoirs below the ground level are normally built to store large quantities of water whereas those of
overhead type are built for direct distribution by gravity flow and are usually of smaller capacity.
A water tank is a container for storing liquid. The need for a water tank is as old as civilization, to
provide storage of water for use in many applications, drinking water, irrigation, agriculture, fire
suppression, agricultural farming, both for plants and livestock, chemical manufacturing, food
preparation as well as many other uses. Water tank parameters include the general design of
the tank, and choice of construction materials, linings. Reinforced Concrete Water tank design
is based on IS 3370: 2009 (Parts I – IV). The design depends on the location of tanks, i.e. overhead, on
ground or underground water tanks. The tanks can be made of RCC or even of steel. The overhead tanks
are usually elevated from the ground level using number of columns and beams. In the other hand the
underground tanks rest below the ground level.
1.1Types of Water Tanks
In this section, the types of water tanks are discussed in detail. There is different type of water tank
depending upon the shape, position with respect to ground level etc. From the position point of view,
water tanks are classified into three categories. Those are,
a) Underground tanks
b) Tanks resting on ground
c) Overhead water tanks
1
In most cases the underground and on ground tank are circular or rectangular in shape but the shape of
the overhead tanks are influenced by the aesthetical view of the surroundings and as well as the design.
1.2 Underground water tank
An Underground storage tank (UST) is a storage tank that is placed below the ground level. Underground
storage tanks fall into three different types:
1. Steel/aluminum tank, made by manufacturers in most states and conforming to standards set by the
Steel Tank Institute.
2. Composite overwrapped a metal tank (aluminum/steel) with filament windings like glass fiber/aramid
or carbon fiber or a plastic compound around the metal cylinder for corrosion protection and to form
an interstitial space.
3. Tanks made from composite material, fiberglass/aramid or carbon fiber with a metal liner (aluminum
or steel).
Underground water storage tanks are used for underground storage of potable drinking water,
wastewater & rainwater collection. So whether you call it a water tank or water cistern, as long as you
are storing water underground these are the storage tanks for you. Plastic underground water tanks
(cistern) are a great alternative to concrete cisterns.
1.3Tanks resting on ground
In this section, we are studying only the tanks resting on ground like clear water reservoirs,
settling tanks, aeration tanks etc. are supported on ground directly. The wall of these tanks is subjected
to pressure and the base is subjected to weight of water. These tanks are rectangular or circular in their
shape.
1.3.1Overhead water tanks
Overhead water tanks of various shapes can be used as service reservoirs, as a balancing tank in
water supply schemes and for replenishing the tanks for various purposes. Reinforced concrete water
towers have distinct advantages as they are not affected by climatic changes, are leak proof, provide
greater rigidity and are adoptable for all shapes.
From the shape point of view, water tanks may be of several types. These are,
a) Circular tanks
b) Conical or funnel shaped tanks
c) Rectangular tanks
2
1.3.2Circular tanks
Circular tanks are usually good for very larger storage capacities the side walls are designed for
circumferential hoop tension and bending moment, since the walls are fixed to the floor slab at the
junction. The co-efficient recommended in IS 3370 part 4 is used to determine the design forces. The
bottom slab is usually flat because it’s quite economical.
1.3.3Conical or funnel shaped tanks
This tank is best in architectural feature and aesthetic this tank has another important advantage
that it’s suitable for high staging the tank’s hollow shaft can be easily built. It can be economical and
rapidly constructed using slip from processing of casting. They can also be built using pre-cast concrete
elements.
1.4Rectangular tanks
The walls of Rectangular tank are subjected to bending moments both in horizontal as well as in
vertical direction. The analysis of moment in the wall is difficult since water pressure results in a
triangular load on them. The magnitude of the moment will depend upon the several factors such as
length, breadth and height of tank, and conditions of the support of the wall at the top and bottom edge.
If the length of the wall is more in compression to its height the moment will be mainly in vertical
direction i.e. the panel will bend as a cantilever. If, however, height is larger in comparison to length,
the moments will be in horizontal direction, and the panel will bend as a thin slab supported on the
edges. The wall of the tank will thus be subjected to both bending moment as well as direct tension.
1.5. Scope of the Project
• To make the study about the analysis and design of water tank.
• To make the guidelines for the design of liquid retaining structure according to IS code.
• To know about design philosophy for safe design of water tank.
• To develop program for water tank to avoid tedious calculations.
• To know economical design of water tank.
This report is to provide guidance in the design and construction for various types of water tanks.
1.6. Sources of Water Supply
The various sources of water can be classified into two categories:
Surface sources such as
1. Ponds and lakes
2. Streams and rivers
3. Storage reservoirs and
3
4. Oceans, generally not used for water supplies, at present.
Sub-surface sources or underground sources, such as
1. Springs
2. Infiltration wells and
3. Wells and Tube-wells.
1.7 Water Quantity Estimation
The quantity of water required for municipal uses for which the water supply scheme has to be
designed requires following data:
Water consumption rate (Per Capita Demand in liters per day per head)
Population to be served
Quantity = per capita demand × Population
Factors affecting per capita demand
➢ Size of the city: Per capita demand for big cities is generally large as compared to that for smaller
towns as big cities have sewer houses.
➢ Presence of industries
➢ Climatic conditions
➢ Habits of economic status
➢ Quality of water
➢ Pressure in the distribution system
➢ Efficiency of water works administration: Leaks in water mains and services; and unauthorized
use of water can be kept to a minimum by surveys.
➢ Cost of water
➢ Policy of metering and charging method: Water tax is charged in two different ways: on the basis
of meter reading and on the basis of certain fixed monthly rate.
1.8 OBJECTIVE
1. To make a study about the analysis and design of water tanks.
2. To make a study about the guidelines for the design of liquid retaining structure according to IS Code.
3. To know about the design philosophy for the safe and economical design of water tank.
4. To develop programs for the design of water tank of flexible base and rigid base and the underground
tank to avoid the tedious calculations.
5. In the end, the programs are validated with the results of manual calculation given in Concrete
Structure
4
CHAPTER- 2
LITERATURE REVIEW
2.1LITERATURE SURVEY:
2.1.1(Mainak Ghosal Ghosal (2019):
Mainak Ghosal Ghosal currently works at the Dr. M. N. Dastur School of Material Sciences, Indian
Institute of Engineering Science and Technology, Shibpur. Mainak Ghosal does research in
Structural Engineering, Materials Engineering and Civil Engineering. Their current project is
'Nano materials in Cement Concrete' base paper Every design comes out when there is a problem.
A design is created to solve the existing problems. People in the region where there is scarcity of
water, don't get enough flow or speed or discharge especially those living on the upper floors in a
multi-storied building. As a consequence people suffer from lack of water due to insufficient
supply for compensating their daily needs. As a first solution of this problem, one needs to develop
a water storage project as has been designed with the help of STAAD principles, known as
rectangular Water Reservoir. The present study reports the analysis and design of an elevated
circular water tank using STAAD. Pro V8i. The design involves load calculations manually and
analyzing the whole structure by STAAD. Pro V8i. The design method used in STAAD. Pro
analysis is Limit State Design and the water tank is subjected to wind load, dead load, self-weight
and hydrostatic load due to water.
2.1.2 L.P. Shrivastava & Akshit Lamba (2018)
A design analysis for water tank based on new IS code 33702009 and draft code of 1893-Part 2.
They considered two mass models one being the impulsive one and the other del. Simulation work
is performed type water tank supported on frame conditions were seismic and wind it was clear
that for elevated tanks,
two degree of freedom idealization of tank showed better results when they were compared with
the one degree of freedom of idealization. The model was loaded with earthquake loads (seismic
loads) followed by Wind loads on the columns of the tank and summed up by considering the selfweight of the entire assembly. Few observations were made – the first being the variation of
hydrodynamic pressures on the geometrical aspects of the tank, the second being the comparison
of total base shear and moment for empty and full conditions of the tank and the last being a
comparative study among time period, base shear and base moment for impulsive and convective
modes of vibration.
2.1.3 Issar Kapadia, Purav Patel, Nilesh Dholiya, Nikunj Patel (2017)
In their paper entitled “Analysis and Design of INTZE Type rectangular Water Tank under the
5
Hydrostatic Pressure as Per IS: 3370 & IS: 456 -2000 by Using STAAD Pro Software”. carried
out the study with help of the STAAD Pro Software, We made the conclusion as pointed There is
an increase in moment when the, height of the structure increases. When using fix joint at the base
its remarkable reduction in base settlement. This type tank is simplest form as compare to the
circular tank. We have given the inclination to the staging of water tank because as respected
inclination the tank performs better than that type of straight one.
2.1.4 Rajkumar, Shivaraj and Prof. Mangalgi (2017)
In their paper entitled “Response-Spectrum Study Of High Rised Intze and Circular Water Tanks”
The total base shear in full tank condition are more than those in empty tank condition and halffilled condition in both seismic zones II and seismic zone V for both Intze and circular type of tank.
Hence design is governed by full tank condition. Design of elevated water tank is very complex
which involves lot of mathematical calculations and time consuming. Hence STAAD pro gives all
parameters which are useful in design of elevated water tank.
2.1.5 Hasan Jasim Mohammed (2016), conclude that:
An application of optimization method to the structural design of concrete rectangular and circular
water tanks, considering the total cost of the tank as an objective function with the properties of the
tank that are tank capacity, width and length of tank in rectangular, water depth in circular, unit
weight of water and tank floor slab thickness, as design variables. A computer program has been
developed to solve numerical examples using the Indian IS: 456-2000 Code equations .The results
shown that the tank capacity taken up the minimum total cost of the rectangular tank and taken
down for circular tank. The tank floor slab thickness taken up the minimum total cost for two types
of tanks. The unit weight of water in tank taken up the minimum total cost of the circular tank and
taken down for rectangular tank.
2.1.6 Vijay K. Puri and Shamsher Prakash, (2014):
Design of foundations in earthquake prone areas needs special considerations. Shallow foundations
may experience a reduction in bearing capacity and increase in settlement and tilt due to seismic
loading. The reduction in bearing capacity depends on the nature and type of soil and ground
acceleration parameters. In the case of piles, the soil-pile behavior under earthquake loading is
generally non-linear. The nonlinearity must be accounted for by defining soil- pile stiffness in terms
of strain dependent soil modulus. A comparison of observed and predicted pile behavior under
dynamic loads has attracted the attention of several investigators. The lateral dynamic pile response
of single piles predicted by analytical models often yields higher natural frequencies and lower
resonant amplitudes compared to those determined from field tests in horizontal vibrations only.
This has been found to be due to overestimated shear modulus and radiation damping of the soil.
6
The authors made an investigation to determine a simple method to improve the theoretical
predictions of piles embedded in fine soils. Based upon this investigation shear strain dependent
reduction factors are proposed for determining the shear modulus and damping for pile response
calculations.
2.1.7Pandey et al. (2015):
Limit state method is widely used at present in comparison to working stress method with the
following advantages: i) Materials are treated according to their properties. ii) Loads are treated
according to their nature. iii) Structures generally fail when they reach their limit state, not their
elastic state. However, when structures reach to their limit state, the cracking width in the structure
may be significantly higher comparative to a structure designed by working stress method at the
same stage. IS: 3370 i.e. the Indian Standard specifications for construction of liquid retaining
structures did not adopt limit state design method for long. However, IS:3370 has adopted the limit
state design method after considering checks over the cracking width. It has been recently adopted in
the new version of IS 3370-2009 concrete structures for storage of liquids – code of practice, while
going through IS 3370 – 2009 it can be found that three methods of design are available.
7
CHAPTER-3
SOFTWARE
General:
STAAD Pro was developed and marketed by Research Engineers International in 1997, but
“BENTLEY”
system acquired this company in 2005. Bentley system is an American
software development company that is actively engaged in developing and marketing
software products for the design, construction, and operation of infrastructure. Design to
help Civil, Mechanical, and Architectural industries by making their analysis and design job
easier, this software supports more than 90 international concrete, steel, timber & aluminum
design codes. Today you will get to know the advantages and career benefits of “BENTLEY
STAADPRO SOFTWARE”
Staad pro is a structural analysis and designing software used to analyze and design of RCC
and Steel structures according to the relative country code. It is one of the most used software
by civil and structural engineers. It helps to automate their tasks by eliminating the tedious
and long procedures of manual methods.
Now staad pro is a commercial version that is being used widely for structural analysis and
design programs products across the world. Most of steel, concrete as well as timber design
code of practice is supported by this program. You can utilize this program for any kind of
structure design and analysis.
Different sort of analysis could be done using this program including the traditional 1st order
static analysis, pushover analysis, or a buckling analysis and geometric non-linear analysis.
3.1.1 Some of the important features of STAAD.Pro:
STAAD Pro provides visualization modules of the building planner which generates models
of building that can be designed and analysis in the software program. This software is
interactive and intuitive that makes easy the work on making changes in the geometry
specification operations with fewer mouse clicks in the workflow.
3.1.2 Physical modelling:
Physical modelling is one of the most significant feature used in the software. It is simplified
physical modeling process of a structure. This software visualize beams, columns and
surface placed in the model corresponding to which they appear in the physical world
8
spanning multiple floors and a surface representing an entire floor of building. The
visualization of generated joints where two physical objects meet in the model.
3.1.3Analytical Modelling:
Analytical model can be created employing the ribbon-based user interfaced by making
changes and editing the command file which are of types like dxf, cis/2. The model geometry
can even be generated from the data of micro-enabled applications by using macros.
3.1.4Steel Autodrafter:
Steel autodrafter produces excellent workflow plan that extracts planer drawings at any level
and sections in any of the orthogonal materials from structural steel models prepared in
STAAD.Pro.
3.1.5Advanced Slab design:
The STAAD.Pro advanced slab design works within the staad,pro environment which is
integrated software design tool workflow. In this software concrete slabs can be defined and
the data can be passed to RAM concepts which includes all the design requirements of
structural and civil design consisting of the geometry, materials, loads and analysis.
3.1.6Advanced Concrete design:
The advanced concrete design workflow software applications powered by RCDC
applications provides direct access for STAAD.Pro models. The software applications is
standalone requiring a model and results data from a suitable analysis, operating outside the
staadpro software environment. The model is made up of beams and columns as plates are
not currently supported. RCDC software applications can be utilized to design the objects
such as pile, footings, columns and walls, beams, and slabs, The software works in within
the projects as each design created in RCDC is retained and displayed when RCDC is reentered balancing the previous design which can be recalled and continued. The BBS of
design which can be generated as required which can be executed instantly.
3.2Advantages of STAAD.Pro Software:
•
First of all it does not required any manual calculations.
•
The visual interface is user-friendly.
•
It based on the latest programming technology that enable to create of an exact 3D
model of the required building or structure.
•
It is suitable for almost all types of materials including concrete, steel, aluminum etc.
9
•
Faster method of designing a structure.
•
The software contains all the necessary tools required to design a structure. It works
in sync with other programs such as pro foundation, staad pro offshore and RAM for
designing foundation, offshore structure and steel structure. Other building, brides,
pipes, shear wall etc can be designed.
•
It can be used to calculate reinforcement for concrete beams, columns and shear walls.
•
A large variety of design codes are available which determines drifts, deflections and
depth of any construction.
•
It is developed with an open architecture called staad.
•
Pre-built models of different are available for remodeling purpose. New templates
can be also be added per requirements.
•
One of the most exciting feature is VBA permits you to create your own design and
templates.
•
We can get shear and moment values at every 1/12th section of the member.
•
For seismic design, both static and response spectrum can be perfomed .
•
You can design structure for different types of loads such as dead loads, wind
loads, live loads, earthquakes loads etc.
• International codes are available.
3.3Key Points:
• STAAD. Pro is designed to help the industries by making their analysis and design
job easier.
• STAAD. Pro saves time as it does not required any manual calculations.
• Multi soft systems is a considerable name for Bentley STAAD. Pro V8i.
10
CHAPTER 4
METHODOLOGY
4.1 DESIGN REQUIREREMENT OF TANK
The rectangular shape is structurally best suited for tank.
➢ Easy formwork and construction process.
➢
The behaviour of rectangular tanks is different from other tanks.
➢ The restrain condition at the base is needed to determine load
conditions.
4.2 DESIGN REQUIREMENT OF CONCRETE (I. S. I)
In water retaining structure a dense impermeable concrete is required therefore, proportion of
fine and course aggregates to cement should be such as to give high quality concrete. Concrete mix
weaker than M20 is not used. The minimum quantity of cement in the concrete mix shall be not less
than 30 kN/m3
The design of the concrete mix shall be such that the resultant concrete is sufficiently impervious.
Efficient compaction preferably by vibration is essential. The permeability of the thoroughly compacted
concrete is dependent on water cement ratio. Increase in water cement ratio increases permeability, while
concrete with low water cement ratio is difficult to compact. Other causes of leakage in concrete are
defects such as segregation and honey combing. All joints should be made water-tight as these are
potential sources of leakage.
11
Fig.4.1. Plan View of Water Tank
Design of liquid retaining structure is different from ordinary R.C.C ,structures as it requires that
concrete should not crack and hence tensile stresses in concrete should be within permissible limits. A
reinforced concrete member of liquid retaining structure is designed on the usual principles ignoring
tensile resistance of concrete in bending. Additional1y it should be ensured that tensile stress on the
liquid retaining face of the equivalent concrete section does not exceed the permissible tensile strength
of concrete as given in table 1. For calculation purposes the cover is also taken into concrete area.
Cracking may be caused due to restraint to shrinkage, expansion and contraction of concrete due to
temperature or shrinkage and swelling due to moisture effects. Such restraint may be caused by.
(i) The interaction between reinforcement and concrete during shrinkage due to drying.
(ii) The boundary conditions.
(iii) The differential conditions prevailing through the large thickness of massive concrete.
Use of small size bars placed properly, leads to closer cracks but of smaller width. The risk of
cracking due to temperature and shrinkage effects may be minimized by limiting the changes in moisture
content and temperature to which the structure as a whole is subjected. The risk of cracking can also be
minimized by reducing the restraint on the free expansion of the structure with long walls or slab founded
at or below ground level, restraint can be minimized by the provision of a sliding layer. This can be
provided by founding the structure on a flat layer of concrete with interposition of some material to
break the bond and facilitate movement.
In case length of structure is large it should be subdivided into suitable lengths separated by
movement joints, especially where sections are changed the movement joints should be provided. Where
structures have to store hot liquids, stresses caused by difference in temperature between inside and
12
outside of the reservoir should be taken into account. The coefficient of expansion due to temperature
change is taken as 11 x 10-6 /° C and coefficient of shrinkage may be taken as 450 x 10-6 for initial
shrinkage and 200 x 10-6 for drying shrinkage.
4.3JOINTS IN LIQUID RETAINING STRUCTURES
4..3.1 MOVEMENT JOINTS. There are three types of movement joints.
(I) Contraction Joint. It is a movement joint with deliberate discontinuity without initial gap between
the concrete on either side of the joint. The purpose of this joint is to accommodate contraction of the
concrete. The joint is shown in Fig.3.2.1 (a).
Fig.4.2.1(a)
A contraction joint may be either complete contraction joint or partial contraction joint. A
complete contraction joint is one in which both steel and concrete are interrupted and a partial
contraction joint is one in which only the concrete is interrupted, the reinforcing steel running through
13
as shown in Fig.4.2.1(b).
(ii)
Expansion Joint. It is a joint with complete discontinuity in both
reinforcing steel and concrete and it is to accommodate either expansion
or contraction of the structure. A typical expansion joint is shown below
4.2.1(c)
This type of joint requires the provision of an initial gap between the adjoining parts of a structure which
by closing or opening accommodates the expansion or contraction of the structure.
(iii) Sliding Joint. It is a joint with complete discontinuity in both reinforcement and concrete and with
special provision to facilitate movement in plane of the joint. A typical joint is shown in Fig. 3.2.1(d)
14
•
4.2.1(d)
This type of joint is provided between wall and floor in some cylindrical tank designs.
4.3.2CONTRACTION JOINTS
This type of joint is provided for convenience in construction. Arrangement is made to achieve
subsequent continuity without relative movement. One application of these joints is between successive
lifts in a reservoir wall. A typical joint is shown in Fig.3.2.2
4.3
The number of joints should be as small as possible and these joints should be kept from possibility of
percolation of water.
4.3.3 TEMPORARY JOINTS
A gap is sometimes left temporarily between the concrete of adjoining parts of a structure which
after a suitable interval and before the structure is put to use, is filled with mortar or concrete completely
as in Fig.3.4(a) or as shown in Fig.3.4 (b) and (c) with suitable jointing materials. In the first case width
of the gap should be sufficient to allow the sides to be prepared before filling.
15
4.4(a)
4.4(b)
4.4(c)
4.3.4
SPACING OF JOINTS
Unless alternative effective means are taken to avoid cracks by allowing for the additional
stresses that may be induced by temperature or shrinkage changes or by unequal settlement, movement
joints should be provided at the following spacing :(a) In reinforced concrete floors, movement joints should be spaced at not more than 7.5m apart in two
directions at right angles. The wall and floor joints should be in line except where sliding joints occur at
the base of the wall in which correspondence is not so important.
(b) For floors with only nominal percentage of reinforcement (smaller than the minimum specified) the
16
concrete floor should be cast in panels with sides not more than 4.5m.
(c) In concrete walls, the movement joints should normally be placed at a maximum spacing of 7.5m. in
reinforced walls and 6m in unreinforced walls. The maximum length desirable between vertical
movement joints will depend upon the tensile strength of the walls, and may be increased by suitable
reinforcement. When a sliding layer is placed at the foundation of a wall, the length of the wall that can
be kept free of cracks depends on the capacity of wall section to resist the friction induced at the planeof
sliding. Approximately the wall has to stand the effect of a force at the place of sliding equal to weight of half the
length of wall multiplied by the co-efficient of friction.
(d) Amongst the movement joints in floors and walls as mentioned above expansion joints should
normally be provided at a spacing of not more than 30m between successive expansion joints or between
the end of the structure and the next expansion joint; all other joints being of the construction type.
(e)When, however, the temperature changes to be accommodated are abnormal or occur more frequently
than usual as in the case of storage of warm liquids or in insulated roof slabs, a smaller spacing than
30m should be adopted that is greater proportion of movement joints should be of the expansion type).
When the range of temperature is small, for example, in certain covered structures, or where restraint is
small, for example, in certain elevated structures none of the movement joints provided in small
structures up to 45mlength need be of the expansion type. Where sliding joints are provided between
the walls and either the floor or roof, the provision of movement joints in each element can be considered
independently.
4.4GENERAL DESIGN REQUIREMENTS (I.S.I)
4.4.1Plain Concrete Structures. Plain concrete member of reinforced concrete liquid retaining
structure may be designed against structural failure by allowing tension in plain concrete as per the
permissible limits for tension in bending. This will automatically take care of failure due to
cracking. However, nominal reinforcement shall be provided, for plain concrete structural members.
4.4.2. Permissible Stresses in Concrete.
(a) For resistance to cracking. For calculations relating to the resistance of members to cracking, the
permissible stresses in tension (direct and due to bending) and shear shall confirm to the values specified
in Table 1. The permissible tensile stresses due to bending apply to the face of the member in contact
with the liquid. In members less than 225mm. thick and in contact with liquid on one side these
permissible stresses in bending apply also to the face remote from the liquid.
(b) For strength calculations. In strength calculations the permissible concrete stresses shall be in
accordance with Table 1. Where the calculated shear stress in concrete alone exceeds the permissible
value, reinforcement acting in conjunction with diagonal compression in the concrete shall be provided
to take the whole of the shear.
17
4.4.3 Permissible Stresses in Steel
(a) For resistance to cracking.
When steel and concrete are assumed to act together for checking the tensile stress in concrete for
avoidance of crack, the tensile stress in steel will be limited by the requirement that the permissible
tensile stress in the concrete is not exceeded so the tensile stress in steel shall be equal to the product of
modular ratio of steel and concrete, and the corresponding allowable tensile stress in concrete.
(b) For strength calculations.
In strength calculations the permissible stress shall be as follows:
(i) Tensile stress in member in direct tension 1000 kg/cm2
(ii) Tensile stress in member in bending on liquid retaining face of members or face away from liquid
for members less than 225mm thick 1000 kg/cm2
(iii) On face away from liquid for members 225mm or more in thickness 1250 kg/cm2
(iv ) Tensile stress in shear reinforcement, For members less than 225mm thickness 1000
kg/cm2 For members 225mm or more in thickness 1250 kg/cm2
(v)Compressive stress in columns subjected to direct load 1250 kg/cm2
4.4.4Stresses due to drying Shrinkage or Temperature Change.
(i) Stresses due to drying shrinkage or temperature change may be ignored provided that.
(a) The permissible stresses specified above in (ii) and (iii) are not otherwise exceeded.
(b) Adequate precautions are taken to avoid cracking of concrete during the construction period and
until the reservoir is put into use.
(c) Recommendation regarding joints given in article 8.3 and for suitable sliding layer beneath the
reservoir are complied with, or the reservoir is to be used only for the storage of water or aqueous liquids
at or near ambient temperature and the circumstances are such that the concrete will never dry out.
18
(ii) Shrinkage stresses may however be required to be calculated in special cases, when a shrinkage co-
efficient of 300 x 10-6may be assumed.
(iii) When the shrinkage stresses are allowed, the permissible stresses, tensile stresses to concrete (direct
and bending) as given in Table 1 may be increased by 33.33 per cent.
4.4.5 Floors
(i) Provision of movement joints.
Movement joints should be provided as discussed in article 3.
(ii) Floors of tanks resting on ground.
If the tank is resting directly over ground, floor may be constructed of concrete with nominal
percentage of reinforcement provided that it is certain that the ground will carry the load without
appreciable subsidence in any part and that the concrete floor is cast in panels with sides not more than
4.5m. with contraction or expansion joints between. In such cases a screed or concrete layer less than
75mm thick shall first be placed. on the ground and covered with a sliding layer of bitumen paper or
other suitable material to destroy the bond between the screed and floor concrete. In normal
circumstances the screed layer shall be of grade not weaker than M10,where injurious soils or aggressive
water are expected, the screed layer shall be of grade not weaker than M 15 and if necessary a sulphate
resisting or other special cement should be used.
(iii) Floor of tanks resting on supports
(a) If the tank is supported on walls or other similar supports the floor slab shall be designed as floor in
buildings for bending moments due to water load and self- weight.
(b) When the floor is rigidly connected to the walls (as is generally the case) the bending moments at the
junction between the walls and floors shall be taken into account in the design of floor together with any
direct forces transferred to the floor from the walls or from the floor to the wall due to suspension of the
floor from the wall.
19
Fig.4.5 Axial Load Application on Wall of Water Tank
If the walls are non-monolithic with the floor slab, such as in cases ,where movement joints have
been provided between the floor slabs and walls, the floor shall be designed only for the vertical loads
on the floor.
(c) In continuous T-beams and L-beams with ribs on the side remote from the liquid, the tension in
concrete on the liquid side at the face of the supports shall not exceed the permissible stresses for
controlling cracks in concrete. The width of the slab shall be determined in usual manner for calculation
of the resistance to cracking of T-beam, L-beam sections at supports.
(d) The floor slab may be suitably tied to the walls by rods properly embedded in both the slab and the
walls. In such cases no separate beam (curved or straight) is necessary under the wall, provided the wall
of the tank itself is designed to act as a beam over the supports under it.
(e) Sometimes it may be economical to provide the floors of circular tanks, in the shape of dome. In such
cases the dome shall be designed for the vertical loads of the liquid over it and the ratio of its rise to its
diameter shall be so adjusted that the stresses in the dome are, as far as possible,
wholly compressive. The dome shall be supported at its bottom on the ring beam which shall be designed
for resultant circumferential tension in addition to vertical loads.
4.4.6 Walls
(i) Provision of joints
(a) Where it is desired to allow the walls to expand or contract separately from the floor, or to prevent
moments at the base of the wall owing to fixity to the floor, sliding joints may be employed.
20
(b) The spacing of vertical movement joints should be as discussed in article 3.3 while the majority of
these joints may be of the partial or complete contraction type, sufficient joints of the expansion type
should be provided to satisfy the requirements given in article
(ii)Pressure on Walls.
(a) In liquid retaining structures with fixed or floating covers the gas pressure developed above liquid
surface shall be added to the liquid pressure.
(b) When the wall of liquid retaining structure is built in ground, or has earth embanked against it, the
effect of earth pressure shall be taken into account.
(iii) Walls or Tanks Rectangular or Polygonal in Plan.
While designing the walls of rectangular or polygonal concrete tanks, the following points should
be borne in mind.
(a) In plane walls, the liquid pressure is resisted by both vertical and horizontal bending moments. An
estimate should be made of the proportion of the pressure resisted by bending moments in the vertical
and horizontal planes. The direct horizontal tension caused by the direct pull due to water pressure on
the end walls, should be added to that resulting from horizontal bending moments. On liquid retaining
faces, the tensile stresses due to the combination of direct horizontal tension and bending action shall
satisfy the following condition:
(t./t )+ ( ó c t . /ó c t ) ≤ 1
t. = calculated direct tensile stress in concrete
t = permissible direct tensile stress in concrete (Table 1)
ó ′c t = calculated tensile stress due to bending in concrete.
Ó c t = permissible tensile stress due to bending in concrete.
(d)At the vertical edges where the walls of a reservoir are rigidly joined, horizontal reinforcement and
haunch bars should be provided to resist the horizontal bending moments even if the walls are designed
to withstand the whole load as vertical beams or cantilever without lateral supports.
(c) In the case of rectangular or polygonal tanks, the side walls act as two way slabs, whereby the wall
is continued or restrained in the horizontal direction, fixed or hinged at the bottom and hinged or free at
the top. The walls thus act as thin plate’s subjected triangular loading and with
boundary conditions varying between full restraint and free edge. The analysis of moment and forces
may be made on the basis of any recognized method.
(iv) Walls of Cylindrical Tanks.
While designing walls of cylindrical tanks the following points should be borne in mind:
21
(a) Walls of cylindrical tanks are either cast monolithically with the base or are set in grooves and key
ways (movement joints). In either case deformation of wall under influence of liquid pressure is
restricted at and above the base. Consequently, only part of the triangular hydrostatic load will be carried
by ring tension and part of the load at bottom will be supported by cantilever action.
Fig.4.6 Load Applications of Water Tank
(b) It is difficult to restrict rotation or settlement of the base slab and it is advisable to provide vertical
reinforcement as if the walls were fully fixed at the base, in addition to the reinforcement required to
resist horizontal ring tension for hinged at base, conditions of walls, unless the appropriate amount of
fixity at the base is established by analysis with due consideration to the dimensions of the base slab the
type of joint between the wall and slab, and , where applicable, the type of soil supporting the base slab.
4.4.7 Roofs
(i) Provision of Movement joints.
To avoid the possibility of sympathetic cracking it is important to ensure that movement joints
in the roof correspond with those in the walls, if roof and walls are monolithic. It, however, provision is
made by means of a sliding joint for movement between the roof and the wall correspondence of joints
is not so important.
(ii)Loading
.
Field covers of liquid retaining structures should be designed for gravity loads, such as the weight
of roof slab, earth cover if any, live loads and mechanical equipment. They should also be designed for
upward load if the liquid retaining structure is subjected to internal gas pressure.
22
A superficial load sufficient to ensure safety with the unequal intensity of loading which occurs
during the placing of the earth cover should be allowed for in designing roofs.
The engineer should specify a loading under these temporary conditions which should not be
exceeded. In designing the roof, allowance should be made for the temporary condition of some spans
loaded and other spans unloaded, even though in the final state the load may be small and evenly
distributed.
Fig.4.7 Plate Load on Water Tank
(iii) Water tightness. In case of tanks intended for the storage of water for domestic purpose, the roof
must be made water-tight. This may be achieved by limiting the stresses as for the rest of the tank, or by
the use of the covering of the waterproof membrane or by providing slopes to
ensure adequate drainage.
(iv) Protection against corrosion. Protection measure shall be provided to the underside of the roof to
prevent it from corrosion due to condensation.
4.4.8
Minimum Reinforcement
(a) The minimum reinforcement in walls, floors and roofs in each of two directions at right angles shall
have an area of 0.3 per cent of the concrete section in that direction for sections up to 100mm, thickness.
For sections of thickness greater than 100mm, and less than 450mm the minimum reinforcement in each
of the two directions shall be linearly reduced from 0.3 percent for 100mm thick section to 0.2 percent
for 450mm, thick sections. For sections of thickness greater than 450mm, minimum reinforcement in
each of the two directions shall be kept at 0.2 per cent.
23
In concrete sections of thickness 225mm or greater, two layers of reinforcement steel shall be
placed one near each face of the section to make up the minimum reinforcement.
(b) In special circumstances floor slabs may be constructed with percentage of reinforcement less than
specified above. In no case the percentage of reinforcement in any member be less than 0°15% of gross
sectional area of the member.
4.4.9
Minimum Cover to Reinforcement.
(a)For liquid faces of parts of members either in contact with the liquid (such as inner faces or roof slab)
the minimum cover to all reinforcement should be 25mm or the diameter of the main bar whichever is
greater. In the presence of the sea water and soils and water of corrosive characters the cover should be
increased by 12mm but this additional cover shall not be taken into account for design calculations.
(b)For faces away from liquid and for parts of the structure neither in contact with the liquid on any face,
nor enclosing the space above the liquid, the cover shall be as for ordinary concrete member.
4.5 FLEXIBLE BASE CIRCULAR WATER TANK
For smaller capacities rectangular tanks are used and for bigger capacities circular tanks are used
. In circular tanks with flexible joint at the base tanks walls are subjected to hydrostatic pressure .so the
tank walls are designed as thin cylinder. As the hoop tension gradually reduces to zero at top, the
reinforcement is gradually reduced to minimum reinforcement at top. The main reinforcement consists
of circular hoops. Vertical reinforcement equal to 0.3% of concrete are is provided and hoop
reinforcement is tied to this reinforcement.
STEP 1
DETERMINATION OF DIAMETER OF THE WATER TANK
Diameter=D= √(Q * 0.004) / ((H - Fb) *
3.14) Where Q=capacity of the water tank
H=height of the water tank
Fb=free board of the water tank
STEP 2
DESIGN OF DOME SHAPED ROOF
Thickness of dome = t=100mm
Live load = 1.5KN/m2
Self -weight of dome = (t / 1000) * unit weight of concrete
Finishes load= 0.1KN/m2
Total load = live load + self- weight + finishes load
24
Central rise= r =1m
Radius of dome = R= ((0.5 * D) ^ 2 + r ^ 2) / (2 * r)
Cos A = ((R - r) /R)
Meridional thrust = (total load * R) / (1 + cos A)
Circumferential thrust = total load * R * (cos A - 1 / (1 + cos A))
Meridional stress = Meridional thrust / t
Hoop stress = circumferential thrust / t
Reinforcement in both direction = 0.3 * t* 10
Hoop tension = meridional thrust * cos A * D * 0.5
Reinforcement in top ring beam =As_ top ring beam hoop tension / Ts
Cross section area of top ring beam
= (hoop tension / PST direct) - (m - 1) * As top ring beam
STEP 3
DETERMINATION OF HOOP REINFORCEMENT
H T I = 0.5 * (w * (H - i) * D)
ASI = H T I / Ts
Where, H T I =hoop tension at a depth of i from the top
A s I =hoop reinforcement at a depth of i from the top
STEP 4
DETERMINATION OF THICKNESS OF CYLINDRICAL WALL
HT = 0.5 * (w * H * D)
t = 0.001 * (HT1 / PST direct - (m - 1) * As)
Where, t=thickness of the wall
HT=hoop tension at the base of tank
PST direct=permissible stress due to direct tension
As=hoop reinforcement at base
STEP 5
DETERMINATION OF VERTICAL REINFORCEMENT
A s v = (0.3 - 0.1 * (t - 100) / 350) * t * 10
Where, A s v= vertical reinforcement of the wall
t=thickness of the wall
25
STEP 6
DESIGN OF BASE
Thickness of base =150mm
Minimum reinforcement required= (0.3/100)*150*1000mm2
4.6 RIGID BASE CIRCULAR TANK
The design of rigid base circular tank can be done by the approximate method. In this method it
is assumed that some portion of the tank at base acts as cantilever and thus some load at bottom are taken
by the cantilever effect. Load in the top portion is taken by the hoop tension. The cantilever effect will
depend on the dimension of the tank and the thickness of the wall. For H2 /Dt between 6 to 12, the
cantilever portion may be assumed at H/3 or 1m from base whichever is more. For H2 /Dt between 6 to
12, the cantilever portion may be assumed at H/4 or 1m from base whichever is more.
STEP 1
DETERMINATION OF DIAMETER OF THE WATER TANK
Diameter=D=√(Q * 0.004) / ((H - Fb) * 3.14)
Where Q=capacity of the water tank
H=height of the water tank
Fb=free board of the water tank
STEP 2
DESIGN OF DOME SHAPED ROOF
Thickness of dome = t=100mm
Live load = 1.5KN/m2
Self -weight of dome = (t / 1000) * unit weight of concrete
Finishes load= 0.1KN/m2
Total load = live load + self- weight + finishes load
Central rise= r =1m
Radius of dome = R= ((0.5 * D) ^ 2 + r ^ 2) / (2 * r)
Cos A = ((R - r) /R)
Meridional thrust = (total load * R) / (1 + cos A)
Circumferential thrust = total load * R * (cos A - 1 / (1 + cos A))
Meridional stress = meridional thrust / t
Hoop stress = circumferential thrust / t
Reinforcement in both direction = 0.3 * t* 10
26
Hoop tension = meridional thrust * cos A * D * 0.5
Reinforcement in top ring beam =As _top ring beam hoop tension / Ts
Cross section area of top ring beam
= (hoop tension / PST direct) - (m - 1) * As _top ring beam
STEP 3
Assume the thickness of the wall=t = 0.15m
Find the value of H ^ 2 / (D * t)
(i) 6 < H ^ 2 / (D * t) < 12
Cantilever height=H/3 or 1m (whichever is more)
(ii) 12 < H ^ 2 / (D * t) < 30
Cantilever height=H/4 or 1m (whichever is more)
STEP 4
DETERMINATION OF REINFORCEMENT IN WALL
Maximum hoop tension=p D/2
Where, p=w*(H-cantilever height)
w=unit weight of water
Area of steel required=maximum hoop tension/ó s t
STEP 5
DETERMINATION OF REINFORCEMENT IN CANTILEVER HEIGHT
Maximum bending moment = 0.5 * (w * H) * (cantilever ^ 2) / 3
Effective depth=t-40mm
Area of steel required=maximum bending moment/(j*effective depth* o s t )
STEP 6
DETERMINATION OF DISTRIBUTION STEEL IN WALL
Distribution steel provided = (0.3 - 0.1 * (t - 100) / 350) * t * 10
STEP 7
DESIGN OF BASE
Thickness of base =150mm
Minimum reinforcement required=(0.3/100)*150*1000mm2
Reinforcement in top ring beam =As _top ring beam hoop tension / Ts
27
4.7 RECTANGULAR WATER TANK
The tanks like purification tanks, Inhofe tanks, septic tanks, and gas holders are built. The design
principle of rectangular tank is same as for tanks are subjected to internal water pressure and outside
earth pressure. The base is subjected to weight of water and soil pressure. These tanks may be covered
at the top.
. As the ratio of the length of tank to its breadth is greater than 2, the long walls will be designed as
cantilevers and the top portion of the short walls will be designed as slab supported by long walls. Bottom
one meter of the short walls will be designed as cantilever slab.
STEP 1
DETERMINATION OF DIMENSION OF THE TANK
Assuming length is equal to the three times of breadth.
Area of the tank = Q / H
B =√ (area of tank / 3)
L=3B
STEP 2
DESIGN OF LONG WALLS
1. first considering that pressure of saturated soil acting from outside and no water pressure from inside,
calculate the depth and over all depth of the walls.
2. Calculate the maximum bending moment at base of long wall.
3. Calculate the area of steel and provide it on the outer face of the walls.
4. Now considering water pressure acting from inside and no earth pressure acting from outside,
calculate the maximum water pressure at base.
5. Calculate the maximum bending moment due to water pressure at base.
6. Calculate the area of steel and provide it on the inner face of the walls.
7. Distribution steel provided = (0.3 - 0.1 * (t - 100) / 350) * t * 10
STEP 3
DESIGN OF SHORT WALLS
1. Bottom 1m acts as cantilever and remaining 3m acts as slab supported on long walls. Calculate the
water pressure at a depth of (H-1) m from top.
2. Calculate the maximum bending moment at support and center.
28
3. Calculate the corresponding area of steel required and provide on the outer face of short wall
respectively.
4. Then the short walls are designed for condition pressure of saturated soil acting from outside and no
earth pressure from inside.
STEP 4
Base slab is check against uplift.
STEP 5
Design of base is done.
Fig.4.8 Plate Stresses are showing
4.8. Statement of Project:
In the results of rectangular tank (resting on ground) 12×4×2.5 having a moderate shear, deflection,
bending moment, etc.
12×4×2.5 sections are given a moderate result for ground resistant water
tank. Cost wise 12×4×2.5 section is more economical in tank resting on
ground.
RCC Wall Thickness: 400 mm
Dimensions:
Length of Tank: 12m
Width of the Tank: 4 m
Depth of the Tank: 2.5 m
Base Slab Thickness: 150 mm
29
Top Slab Thickness: 150 mm
4
Fig 4.9
12
fig 4.10
12
30
Fig.4.11 3D Rendering view of Rectangular water Tank
31
CHAPTER 5
RESULT AND DISCUSSION
5.1 Design of Rectangular Tank
Capacity= 120m3
Depth of the tank = 4m
Compressive strength of concrete= M20
Free board= 0.2m
Diameter of bars used= 16mm
Angle of repose of soil= 30 degree
Unit weight of soil= 16KN/mm3
Unit weight of water= 10KN/ mm3
32
33
RESULTS:
***TOTAL APPLIED LOAD ( KN METE ) SUMMARY (LOADING
SUMMATION FORCE-X =
625.00
SUMMATION FORCE-Y =
-2000.00
SUMMATION FORCE-Z =
-1000.00
1)
SUMMATION OF MOMENTS AROUND THE ORIGINMX=
4166.67 MY=
5562.50 MZ=
-8520.83
***TOTAL REACTION LOAD ( KN METE ) SUMMARY (LOADING
SUMMATION FORCE-X =
-625.00
SUMMATION FORCE-Y =
2000.00
SUMMATION FORCE-Z =
1000.00
SUMMATION OF MOMENTS AROUND THE ORIGINMX=
-4166.67 MY=
-5562.50 MZ=
8520.83
MAXIMUM DISPLACEMENTS ( CM /RADIANS) (LOADING
MAXIMUMS
AT NODE
X = 2.86133E-02
124
Y = 1.27451E-03
146
Z = -1.28026E-01
174
RX= -6.42245E-04
76
RY= -4.45913E-04
101
RZ= -1.37077E-04
208
11
7.49
48.16
12
-25.00
16.83
0.00 -25.00
1.20
13
0.00 -50.00
1.07
14
6.48
0.00 -25.00
0.47
15
2.10
-0.49
0.00 -50.00
0.40
-1.10
0.00
0.00
0.00
0.00
-46.22
0.00
0.00
0.00 111000
0.00
0.00
0.00
0.00
0.95
0.00
0.00
0.00 111000
0.00
0.43
0.00
0.32
0.00
0.22
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00 111000
34
1)
1)
16 0.00 -25.00
0.21
17
0.00
0.15
18
0.00
0.02
19
0.00
-0.06
20
0.00
-0.54
21
0.00
-0.56
22
0.00
-3.15
23
0.00
-2.32
24
7.49
0.01
-50.00
-0.11
-25.00
0.21
-50.00
0.99
-25.00
-0.23
-50.00
-3.07
-25.00
-0.46
-50.00
9.61
-25.00
13.28 -31.50
25
0.00
-50.00
1.66 -38.37
26
7.49
54.70
27
28
29
0.00
-50.00
7.88
0.00
-50.00
0.40
-1.32
0.00
0.00
0.17
31
33.88
0.81
0.24
30
-25.00
0.00
0.09 -6.67
-50.00
-0.06
-50.00
1.37
0.00
0.00
0.00
0.00
0.13
0.00
0.00
0.00 111000
0.00
0.05
0.00
0.16
0.00
-0.11
0.00
0.66
0.00
-0.49
0.00
3.14
0.00
-2.57
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00
0.00
0.00
-43.99
0.00
0.00
0.00 111000
0.00
0.00
0.00
0.00
-2.29
0.00
0.00
0.00 111000
0.00
0.00
0.00
0.00
-54.67
0.00
0.00
0.00 111000
0.00
0.00
0.00
0.00
-0.72
0.00
-0.25
0.00
-0.18
0.00
-0.34
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00 111000
0.00
0.00 111000
-50.00
0.00
0.00
0.00
0.00
-0.82
0.00
0.00
0.00
111000
35
32
0.00 -50.00
0.00
-0.04
-1.68
28.59
0.00
0.00
0.00
0.00
0.00
0.00 111000
STAD PRO INPUT RESULTS:
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 31-Jan-17
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 0 0; 2 8 0 0; 3 8 0 5; 4 0 0 5; 5 0 2.5 0; 6 8 2.5 0; 7 0 2.5 5; 8 8 2.5 5;
9 1 0 0; 10 1 0 1; 11 0 0 1; 12 2 0 0; 13 2 0 1; 14 3 0 0; 15 3 0 1; 16 4 0 0;
17 4 0 1; 18 5 0 0; 19 5 0 1; 20 6 0 0; 21 6 0 1; 22 7 0 0; 23 7 0 1; 24 8 0 1;
25 1 0 2; 26 0 0 2; 27 2 0 2; 28 3 0 2; 29 4 0 2; 30 5 0 2; 31 6 0 2; 32 7 0 2;
33 8 0 2; 34 1 0 3; 35 0 0 3; 36 2 0 3; 37 3 0 3; 38 4 0 3; 39 5 0 3; 40 6 0 3;
41 7 0 3; 42 8 0 3; 43 1 0 4; 44 0 0 4; 45 2 0 4; 46 3 0 4; 47 4 0 4; 48 5 0 4;
49 6 0 4; 50 7 0 4; 51 8 0 4; 52 1 0 5; 53 2 0 5; 54 3 0 5; 55 4 0 5; 56 5 0 5;
57 6 0 5; 58 7 0 5; 59 0 0.3125 0; 60 1.6 0.3125 0; 61 1.6 0 0; 62 0 0.625 0;
63 1.6 0.625 0; 64 0 0.9375 0; 65 1.6 0.9375 0; 66 0 1.25 0; 67 1.6 1.25 0;
68 0 1.5625 0; 69 1.6 1.5625 0; 70 0 1.875 0; 71 1.6 1.875 0; 72 0 2.1875 0;
73 1.6 2.1875 0; 74 1.6 2.5 0; 75 3.2 0.3125 0; 76 3.2 0 0; 77 3.2 0.625 0;
78 3.2 0.9375 0; 79 3.2 1.25 0; 80 3.2 1.5625 0; 81 3.2 1.875 0;
82 3.2 2.1875 0; 83 3.2 2.5 0; 84 4.8 0.3125 0; 85 4.8 0 0; 86 4.8 0.625 0;
87 4.8 0.9375 0; 88 4.8 1.25 0; 89 4.8 1.5625 0; 90 4.8 1.875 0;
91 4.8 2.1875 0; 92 4.8 2.5 0; 93 6.4 0.3125 0; 94 6.4 0 0; 95 6.4 0.625 0;
96 6.4 0.9375 0; 97 6.4 1.25 0; 98 6.4 1.5625 0; 99 6.4 1.875 0;
100 6.4 2.1875 0; 101 6.4 2.5 0; 102 8 0.3125 0; 103 8 0.625 0; 104 8 0.9375 0;
105 8 1.25 0; 106 8 1.5625 0; 107 8 1.875 0; 108 8 2.1875 0; 109 0 0.3125 1;
110 0 0.625 1; 111 0 0.9375 1; 112 0 1.25 1; 113 0 1.5625 1; 114 0 1.875 1;
115 0 2.1875 1; 116 0 2.5 1; 117 0 0.3125 2; 118 0 0.625 2; 119 0 0.9375 2;
120 0 1.25 2; 121 0 1.5625 2; 122 0 1.875 2; 123 0 2.1875 2; 124 0 2.5 2;
36
125 0 0.3125 3; 126 0 0.625 3; 127 0 0.9375 3; 128 0 1.25 3; 129 0 1.5625 3;
130 0 1.875 3; 131 0 2.1875 3; 132 0 2.5 3; 133 0 0.3125 4; 134 0 0.625 4;
135 0 0.9375 4; 136 0 1.25 4; 137 0 1.5625 4; 138 0 1.875 4; 139 0 2.1875 4;
140 0 2.5 4; 141 0 0.3125 5; 142 0 0.625 5; 143 0 0.9375 5; 144 0 1.25 5;
145 0 1.5625 5; 146 0 1.875 5; 147 0 2.1875 5; 148 1.6 0.3125 5; 149 1.6 0 5;
150 1.6 0.625 5; 151 1.6 0.9375 5; 152 1.6 1.25 5; 153 1.6 1.5625 5;
154 1.6 1.875 5; 155 1.6 2.1875 5; 156 1.6 2.5 5; 157 3.2 0.3125 5;
158 3.2 0 5; 159 3.2 0.625 5; 160 3.2 0.9375 5; 161 3.2 1.25 5;
162 3.2 1.5625 5; 163 3.2 1.875 5; 164 3.2 2.1875 5; 165 3.2 2.5 5;
166 4.8 0.3125 5; 167 4.8 0 5; 168 4.8 0.625 5; 169 4.8 0.9375 5;
170 4.8 1.25 5; 171 4.8 1.5625 5; 172 4.8 1.875 5; 173 4.8 2.1875 5;
174 4.8 2.5 5; 175 6.4 0.3125 5; 176 6.4 0 5; 177 6.4 0.625 5;
178 6.4 0.9375 5; 179 6.4 1.25 5; 180 6.4 1.5625 5; 181 6.4 1.875 5;
182 6.4 2.1875 5; 183 6.4 2.5 5; 184 8 0.3125 5; 185 8 0.625 5; 186 8 0.9375 5;
187 8 1.25 5; 188 8 1.5625 5; 189 8 1.875 5; 190 8 2.1875 5; 191 8 0.3125 1;
192 8 0.625 1; 193 8 0.9375 1; 194 8 1.25 1; 195 8 1.5625 1; 196 8 1.875 1;
197 8 2.1875 1; 198 8 2.5 1; 199 8 0.3125 2; 200 8 0.625 2; 201 8 0.9375 2;
202 8 1.25 2; 203 8 1.5625 2; 204 8 1.875 2; 205 8 2.1875 2; 206 8 2.5 2;
207 8 0.3125 3; 208 8 0.625 3; 209 8 0.9375 3; 210 8 1.25 3; 211 8 1.5625 3;
212 8 1.875 3; 213 8 2.1875 3; 214 8 2.5 3; 215 8 0.3125 4; 216 8 0.625 4;
217 8 0.9375 4; 218 8 1.25 4; 219 8 1.5625 4; 220 8 1.875 4; 221 8 2.1875 4;
222 8 2.5 4;
ELEMENT INCIDENCES SHELL
6 1 9 10 11; 7 9 12 13 10; 8 12 14 15 13; 9 14 16 17 15; 10 16 18 19 17;
11 18 20 21 19; 12 20 22 23 21; 13 22 2 24 23; 14 11 10 25 26; 15 10 13 27 25;
16 13 15 28 27; 17 15 17 29 28; 18 17 19 30 29; 19 19 21 31 30; 20 21 23 32 31;
21 23 24 33 32; 22 26 25 34 35; 23 25 27 36 34; 24 27 28 37 36; 25 28 29 38 37;
26 29 30 39 38; 27 30 31 40 39; 28 31 32 41 40; 29 32 33 42 41; 30 35 34 43 44;
31 34 36 45 43; 32 36 37 46 45; 33 37 38 47 46; 34 38 39 48 47; 35 39 40 49 48;
36 40 41 50 49; 37 41 42 51 50; 38 44 43 52 4; 39 43 45 53 52; 40 45 46 54 53;
41 46 47 55 54; 42 47 48 56 55; 43 48 49 57 56; 44 49 50 58 57; 45 50 51 3 58;
46 1 59 60 61; 47 59 62 63 60; 48 62 64 65 63; 49 64 66 67 65; 50 66 68 69 67;
37
51 68 70 71 69; 52 70 72 73 71; 53 72 5 74 73; 54 61 60 75 76; 55 60 63 77 75;
56 63 65 78 77; 57 65 67 79 78; 58 67 69 80 79; 59 69 71 81 80; 60 71 73 82 81;
61 73 74 83 82; 62 76 75 84 85; 63 75 77 86 84; 64 77 78 87 86; 65 78 79 88 87;
66 79 80 89 88; 67 80 81 90 89; 68 81 82 91 90; 69 82 83 92 91; 70 85 84 93 94;
71 84 86 95 93; 72 86 87 96 95; 73 87 88 97 96; 74 88 89 98 97; 75 89 90 99 98;
76 90 91 100 99; 77 91 92 101 100; 78 94 93 102 2; 79 93 95 103 102;
80 95 96 104 103; 81 96 97 105 104; 82 97 98 106 105; 83 98 99 107 106;
84 99 100 108 107; 85 100 101 6 108; 86 1 59 109 11; 87 59 62 110 109;
88 62 64 111 110; 89 64 66 112 111; 90 66 68 113 112; 91 68 70 114 113;
92 70 72 115 114; 93 72 5 116 115; 94 11 109 117 26; 95 109 110 118 117;
96 110 111 119 118; 97 111 112 120 119; 98 112 113 121 120; 99 113 114 122 121;
100 114 115 123 122; 101 115 116 124 123; 102 26 117 125 35;
103 117 118 126 125; 104 118 119 127 126; 105 119 120 128 127;
106 120 121 129 128; 107 121 122 130 129; 108 122 123 131 130;
109 123 124 132 131; 110 35 125 133 44; 111 125 126 134 133;
112 126 127 135 134; 113 127 128 136 135; 114 128 129 137 136;
115 129 130 138 137; 116 130 131 139 138; 117 131 132 140 139;
118 44 133 141 4; 119 133 134 142 141; 120 134 135 143 142;
121 135 136 144 143; 122 136 137 145 144; 123 137 138 146 145;
124 138 139 147 146; 125 139 140 7 147; 126 4 141 148 149; 127 141 142 150 148;
128 142 143 151 150; 129 143 144 152 151; 130 144 145 153 152;
131 145 146 154 153; 132 146 147 155 154; 133 147 7 156 155;
134 149 148 157 158; 135 148 150 159 157; 136 150 151 160 159;
137 151 152 161 160; 138 152 153 162 161; 139 153 154 163 162;
140 154 155 164 163; 141 155 156 165 164; 142 158 157 166 167;
143 157 159 168 166; 144 159 160 169 168; 145 160 161 170 169;
146 161 162 171 170; 147 162 163 172 171; 148 163 164 173 172;
149 164 165 174 173; 150 167 166 175 176; 151 166 168 177 175;
152 168 169 178 177; 153 169 170 179 178; 154 170 171 180 179;
155 171 172 181 180; 156 172 173 182 181; 157 173 174 183 182;
158 176 175 184 3; 159 175 177 185 184; 160 177 178 186 185;
161 178 179 187 186; 162 179 180 188 187; 163 180 181 189 188;
38
164 181 182 190 189; 165 182 183 8 190; 166 2 102 191 24; 167 102 103 192 191;
168 103 104 193 192; 169 104 105 194 193; 170 105 106 195 194;
171 106 107 196 195; 172 107 108 197 196; 173 108 6 198 197; 174 24 191 199 33;
175 191 192 200 199; 176 192 193 201 200; 177 193 194 202 201;
178 194 195 203 202; 179 195 196 204 203; 180 196 197 205 204;
181 197 198 206 205; 182 33 199 207 42; 183 199 200 208 207;
184 200 201 209 208; 185 201 202 210 209; 186 202 203 211 210;
187 203 204 212 211; 188 204 205 213 212; 189 205 206 214 213;
190 42 207 215 51; 191 207 208 216 215; 192 208 209 217 216;
193 209 210 218 217; 194 210 211 219 218; 195 211 212 220 219;
196 212 213 221 220; 197 213 214 222 221; 198 51 215 184 3;
199 215 216 185 184; 200 216 217 186 185; 201 217 218 187 186;
202 218 219 188 187; 203 219 220 189 188; 204 220 221 190 189;
205 221 222 8 190;
ELEMENT PROPERTY
4 TO 205 THICKNESS 0.4
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 2.17185e+007
POISSON 0.17
DENSITY 23.5616
ALPHA 1e-005
DAMP 0.05
TYPE CONCRETE
STRENGTH FCU 27579
END DEFINE MATERIAL
CONSTANTS
MATERIAL CONCRETE ALL
SUPPORTS
1 TO 4 9 TO 58 61 76 85 94 149 158 167 176 PINNED
LOAD 1 LOADTYPE None TITLE LOAD CASE 1
39
ELEMENT LOAD
7 TRAP JT 50 50 50 50
8 TRAP JT 50 50 50 50
9 TRAP JT 50 50 50 50
10 TRAP JT 50 50 50 50
11 TRAP JT 50 50 50 50
12 TRAP JT 50 50 50 50
13 TRAP JT 50 50 50 50
14 TRAP JT 50 50 50 50
15 TRAP JT 50 50 50 50
16 TRAP JT 50 50 50 50
17 TRAP JT 50 50 50 50
18 TRAP JT 50 50 50 50
19 TRAP JT 50 50 50 50
20 TRAP JT 50 50 50 50
21 TRAP JT 50 50 50 50
22 TRAP JT 50 50 50 50
23 TRAP JT 50 50 50 50
24 TRAP JT 50 50 50 50
25 TRAP JT 50 50 50 50
26 TRAP JT 50 50 50 50
27 TRAP JT 50 50 50 50
28 TRAP JT 50 50 50 50
29 TRAP JT 50 50 50 50
30 TRAP JT 50 50 50 50
31 TRAP JT 50 50 50 50
32 TRAP JT 50 50 50 50
33 TRAP JT 50 50 50 50
34 TRAP JT 50 50 50 50
35 TRAP JT 50 50 50 50
36 TRAP JT 50 50 50 50
37 TRAP JT 50 50 50 50
40
38 TRAP JT 50 50 50 50
39 TRAP JT 50 50 50 50
40 TRAP JT 50 50 50 50
41 TRAP JT 50 50 50 50
42 TRAP JT 50 50 50 50
43 TRAP JT 50 50 50 50
44 TRAP JT 50 50 50 50
45 TRAP JT 50 50 50 50
46 TRAP JT 50 43.75 43.75 50
47 TRAP JT 43.75 37.5 37.5 43.75
48 TRAP JT 37.5 31.25 31.25 37.5
49 TRAP JT 31.25 25 25 31.25
50 TRAP JT 25 18.75 18.75 25
51 TRAP JT 18.75 12.5 12.5 18.75
52 TRAP JT 12.5 6.25 6.25 12.5
53 TRAP JT 6.25 0 0 6.25
54 TRAP JT 50 43.75 43.75 50
55 TRAP JT 43.75 37.5 37.5 43.75
56 TRAP JT 37.5 31.25 31.25 37.5
57 TRAP JT 31.25 25 25 31.25
58 TRAP JT 25 18.75 18.75 25
59 TRAP JT 18.75 12.5 12.5 18.75
60 TRAP JT 12.5 6.25 6.25 12.5
61 TRAP JT 6.25 0 0 6.25
62 TRAP JT 50 43.75 43.75 50
63 TRAP JT 43.75 37.5 37.5 43.75
64 TRAP JT 37.5 31.25 31.25 37.5
65 TRAP JT 31.25 25 25 31.25
66 TRAP JT 25 18.75 18.75 25
67 TRAP JT 18.75 12.5 12.5 18.75
68 TRAP JT 12.5 6.25 6.25 12.5
69 TRAP JT 6.25 0 0 6.25
41
70 TRAP JT 50 43.75 43.75 50
71 TRAP JT 43.75 37.5 37.5 43.75
72 TRAP JT 37.5 31.25 31.25 37.5
73 TRAP JT 31.25 25 25 31.25
74 TRAP JT 25 18.75 18.75 25
75 TRAP JT 18.75 12.5 12.5 18.75
76 TRAP JT 12.5 6.25 6.25 12.5
77 TRAP JT 6.25 0 0 6.25
78 TRAP JT 50 43.75 43.75 50
79 TRAP JT 43.75 37.5 37.5 43.75
80 TRAP JT 37.5 31.25 31.25 37.5
81 TRAP JT 31.25 25 25 31.25
82 TRAP JT 25 18.75 18.75 25
83 TRAP JT 18.75 12.5 12.5 18.75
84 TRAP JT 12.5 6.25 6.25 12.5
85 TRAP JT 6.25 0 0 6.25
86 TRAP JT 50 43.75 43.75 50
87 TRAP JT 43.75 37.5 37.5 43.75
88 TRAP JT 37.5 31.25 31.25 37.5
89 TRAP JT 31.25 25 25 31.25
90 TRAP JT 25 18.75 18.75 25
91 TRAP JT 18.75 12.5 12.5 18.75
92 TRAP JT 12.5 6.25 6.25 12.5
93 TRAP JT 6.25 0 0 6.25
94 TRAP JT 50 43.75 43.75 50
95 TRAP JT 43.75 37.5 37.5 43.75
96 TRAP JT 37.5 31.25 31.25 37.5
97 TRAP JT 31.25 25 25 31.25
98 TRAP JT 25 18.75 18.75 25
99 TRAP JT 18.75 12.5 12.5 18.75
100 TRAP JT 12.5 6.25 6.25 12.5
101 TRAP JT 6.25 0 0 6.25
42
102 TRAP JT 50 43.75 43.75 50
103 TRAP JT 43.75 37.5 37.5 43.75
104 TRAP JT 37.5 31.25 31.25 37.5
105 TRAP JT 31.25 25 25 31.25
106 TRAP JT 25 18.75 18.75 25
107 TRAP JT 18.75 12.5 12.5 18.75
108 TRAP JT 12.5 6.25 6.25 12.5
109 TRAP JT 6.25 0 0 6.25
110 TRAP JT 50 43.75 43.75 50
111 TRAP JT 43.75 37.5 37.5 43.75
112 TRAP JT 37.5 31.25 31.25 37.5
113 TRAP JT 31.25 25 25 31.25
114 TRAP JT 25 18.75 18.75 25
115 TRAP JT 18.75 12.5 12.5 18.75
116 TRAP JT 12.5 6.25 6.25 12.5
117 TRAP JT 6.25 0 0 6.25
118 TRAP JT 50 43.75 43.75 50
119 TRAP JT 43.75 37.5 37.5 43.75
120 TRAP JT 37.5 31.25 31.25 37.5
121 TRAP JT 31.25 25 25 31.25
122 TRAP JT 25 18.75 18.75 25
123 TRAP JT 18.75 12.5 12.5 18.75
124 TRAP JT 12.5 6.25 6.25 12.5
125 TRAP JT 6.25 0 0 6.25
126 TRAP JT 50 43.75 43.75 50
127 TRAP JT 43.75 37.5 37.5 43.75
128 TRAP JT 37.5 31.25 31.25 37.5
129 TRAP JT 31.25 25 25 31.25
130 TRAP JT 25 18.75 18.75 25
131 TRAP JT 18.75 12.5 12.5 18.75
132 TRAP JT 12.5 6.25 6.25 12.5
133 TRAP JT 6.25 0 0 6.25
43
134 TRAP JT 50 43.75 43.75 50
135 TRAP JT 43.75 37.5 37.5 43.75
136 TRAP JT 37.5 31.25 31.25 37.5
137 TRAP JT 31.25 25 25 31.25
138 TRAP JT 25 18.75 18.75 25
139 TRAP JT 18.75 12.5 12.5 18.75
140 TRAP JT 12.5 6.25 6.25 12.5
141 TRAP JT 6.25 0 0 6.25
142 TRAP JT 50 43.75 43.75 50
143 TRAP JT 43.75 37.5 37.5 43.75
144 TRAP JT 37.5 31.25 31.25 37.5
145 TRAP JT 31.25 25 25 31.25
146 TRAP JT 25 18.75 18.75 25
147 TRAP JT 18.75 12.5 12.5 18.75
148 TRAP JT 12.5 6.25 6.25 12.5
149 TRAP JT 6.25 0 0 6.25
150 TRAP JT 50 43.75 43.75 50
151 TRAP JT 43.75 37.5 37.5 43.75
152 TRAP JT 37.5 31.25 31.25 37.5
153 TRAP JT 31.25 25 25 31.25
154 TRAP JT 25 18.75 18.75 25
155 TRAP JT 18.75 12.5 12.5 18.75
156 TRAP JT 12.5 6.25 6.25 12.5
157 TRAP JT 6.25 0 0 6.25
158 TRAP JT 50 43.75 43.75 50
159 TRAP JT 43.75 37.5 37.5 43.75
160 TRAP JT 37.5 31.25 31.25 37.5
161 TRAP JT 31.25 25 25 31.25
162 TRAP JT 25 18.75 18.75 25
163 TRAP JT 18.75 12.5 12.5 18.75
164 TRAP JT 12.5 6.25 6.25 12.5
165 TRAP JT 6.25 0 0 6.25
44
166 TRAP JT 50 43.75 43.75 50
167 TRAP JT 43.75 37.5 37.5 43.75
168 TRAP JT 37.5 31.25 31.25 37.5
169 TRAP JT 31.25 25 25 31.25
170 TRAP JT 25 18.75 18.75 25
171 TRAP JT 18.75 12.5 12.5 18.75
172 TRAP JT 12.5 6.25 6.25 12.5
173 TRAP JT 6.25 0 0 6.25
174 TRAP JT 50 43.75 43.75 50
175 TRAP JT 43.75 37.5 37.5 43.75
176 TRAP JT 37.5 31.25 31.25 37.5
177 TRAP JT 31.25 25 25 31.25
178 TRAP JT 25 18.75 18.75 25
179 TRAP JT 18.75 12.5 12.5 18.75
180 TRAP JT 12.5 6.25 6.25 12.5
181 TRAP JT 6.25 0 0 6.25
182 TRAP JT 50 43.75 43.75 50
183 TRAP JT 43.75 37.5 37.5 43.75
184 TRAP JT 37.5 31.25 31.25 37.5
185 TRAP JT 31.25 25 25 31.25
186 TRAP JT 25 18.75 18.75 25
187 TRAP JT 18.75 12.5 12.5 18.75
188 TRAP JT 12.5 6.25 6.25 12.5
189 TRAP JT 6.25 0 0 6.25
190 TRAP JT 50 43.75 43.75 50
191 TRAP JT 43.75 37.5 37.5 43.75
192 TRAP JT 37.5 31.25 31.25 37.5
193 TRAP JT 31.25 25 25 31.25
194 TRAP JT 25 18.75 18.75 25
195 TRAP JT 18.75 12.5 12.5 18.75
196 TRAP JT 12.5 6.25 6.25 12.5
197 TRAP JT 6.25 0 0 6.25
45
198 TRAP JT 50 43.75 43.75 50
199 TRAP JT 43.75 37.5 37.5 43.75
200 TRAP JT 37.5 31.25 31.25 37.5
201 TRAP JT 31.25 25 25 31.25
202 TRAP JT 25 18.75 18.75 25
203 TRAP JT 18.75 12.5 12.5 18.75
204 TRAP JT 12.5 6.25 6.25 12.5
205 TRAP JT 6.25 0 0 6.25
6 TRAP JT 50 50 50 50
LOAD 2 LOADTYPE None TITLE LOAD CASE 2
ELEMENT LOAD
6 TO 45 PR GY -50
PERFORM ANALYSIS PRINT ALL
PRINT ANALYSIS RESULTS
START CONCRETE DESIGN
CODE INDIAN
FC 25 ALL
FYMAIN 415 MEMB 6 TO 45
CONCRETE TAKE
END CONCRETE DESIGN
FINISH
46
CHAPTER 6
CONCLUSION
Storage of water in the form of tanks for drinking and washing purposes, swimming pools for
exercise and enjoyment, and sewage sedimentation tanks are gaining increasing importance in the
presentday life. For small capacities we go for rectangular water tanks while for bigger capacities we
provide circular water tanks.
Design of water tank is a very tedious method. Particularly design of rectangular water tank
involves lots of mathematical formulae and calculation. It is also time consuming. Hence program gives
a solution to the above problems.
There is a little difference between the design values of program to that of manual calculation. The
program gives the least value for the design. Hence designer should not provide less than the values we
get from the program. In case of theoretical calculation designer initially add some extra values to the
obtained values to be in safer side.
➢ Increase in shear force & bending moment becomes milder as one goes towards downwards side
of slope.
➢ It is seen from the results that the formwork required for the constructions of water tanks is
minimum for circular shaped tank as compared to square shaped and rectangular shaped tanks.
➢ It is possible to formulate and obtain solution for the minimum cost design for rectangular tank.
➢ The designed RCC rectangular tank can store water up to 192000 liters.
➢ This design project we have analyzed the rectangular RCC water tank, through theoretical design
and STAAD pro program.
➢ limit state method was found to be most economical design of water tanks as the quantity of steel
and concrete needed is less as compared to working stress method.
47
CHAPTER 7
REFERENCES
1. Bhandari.M , Karan Deep Singh, “Economic Design of Water Tank of Different Shapes With
Reference To IS: 3370-2009”, International Journal of Modern Engineering Research (IJMER),
Volume 4, Issue 12, ISSN: 2249-6645, Dec-2014.
2. Bhandari .M , Karan Deep Singh, “Comparative Study of Design of Water Tank With Reference
to IS 3370”, International Journal of Emerging Technology and Advanced Engineering, Volume
4, Issue 11, ISSN: 2250-2459, Nov-2014.
3. Ranjit Singh Lodhi, Dr. Abhay Sharma, Dr. Vivek Garg, “Design of Intze Tank in Perspective
of Revision of IS :3370”, International Journal of Scientific Engineering and Technology,
Volume No.3, Issue No.9, pp:1193-1197, ISSN :2277-1581, Sep-2014.
4. Neeta .K Meshram , Dr. P. S. Pajgade, “Comparative Study of Water Tank Using Limit State
Method and Working Stress Method”, International Journal of Research in Advent Technology,
Volume 2, Issue 8, ISSN: 2321-9637, Aug-2014.
5. Aditya Wad, Gore N. G, Salunke P. J, Sayagavi V. G, “Cost Optimization of Rectangular RCC
Underground Tank”, International Journal of Recent Technology and Engineering (IJRTE),
Volume 3, Issue 3, ISSN: 2277-3878, July-2014.
6. Manish N. Gandhi, Rajan .A, “Necessity of Dynamic Analysis of Elevated Water Storage
Structure Using Different Bracing in Staging”, International Journal of Research in Advent
Technology, Volume 2, Issue 2, ISSN:2321-9637, Feb-2014.
7. Riyaz Sameer, Mundhada A.R, Snehal Metkar, “Comparison of RCC and Pre-stressed Concrete
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