ABSTRACT

Liquid tanks and especially the elevated tanks are structures of high importance which are

considered as the main lifeline elements that should be capable of keeping the expected

performance. i.e. operation during and after earthquakes. Earlier design of water tanks was

being done using the working stress method given in IS: 3370 1965. This method leads to

thicker and heavily reinforced sections. The use of limit state method of design has been

adopted in the revised code IS 3370: 2009 and provision for checking the crack width is also

included in this code. Design and cost estimation of overhead water tanks is a time consuming

task, which requires a great deal of expertise. This study therefore examines the efficiency of

Square tanks. In order to draw reasonable inferences on tank design effectiveness, relative cost

implications of tank types and structural capacities. This study is carried out to analyse the cost

of overhead water tanks of varying capacities having square type water tank by working stress

method and limit state method so as to determine the most economical of the tank.

This project gives in brief, the theory behind the design of liquid retaining structure

(Elevated circular water tank with domed roof and conical base) using working stress method.

Elements are design in limit state method. Additionally, the project explores design of water

tank specifically for RAJKIYA ENGG. COLLEGE, AZAMGARH according to respective

standard data of the college. The final section describes detailed estimation aspect according

to the calculated data sheet.

INTRODUCTION

A water tank is used to store water to tide over the daily requirement. In the

Construction of concrete structure for the storage of water and other liquids the Imperviousness

of concrete is most essential .The permeability of any uniform and thoroughly compacted

concrete of given mix proportions is mainly dependent on water cement ratio .The increase in

water cement ratio results in increase in the permeability .The decrease in water cement ratio

will therefore be desirable to decrease the permeability, but very much reduced water cement

ratio may cause compact ion difficulties and prove to be harmful also. Design of liquid retaining

structure has to be based on the avoidance of cracking in the concrete having regard to its

tensile strength. Cracks can be prevented by avoiding the use of thick timber shuttering which

prevent the easy escape of heat of hydration from the concrete mass the risk of cracking can

also be minimized by reducing the restraints on free expansion or contraction of the structure.

This tank is designed under working stress method for serviceability because tank is

designed for long time of service and by this we escape from maintenance and element of intze

tank are prepared under limit state method for removal of crack and leakage.

The current strength of RAJKIYA ENGINEERING COLLEGE is 812 student 50 faculty and

200 worker approx including mess member but in case of future development of college

strength of student will rise upto 1500 and faculty will be 300( including their family member)

and worker will be rise upto 500( including their family member) .

This tank is designed for RAJKIYA ENGINEERING COLLEGE for various purpose

like for drinking, in bathroom, in mesh for cooking, washing of clothes washing for utensils,

washing and cleaning of hostel, mess, academic, lawn of watering and gardening, flushing of

water closets etc

OBJECTIVE

The objective of present work is to study the design and estimation of intze tank and to know

about the philosophy for the safe and economical design of water tank under the guidelines

for the design of liquid retaining Structure as per IS code.

SCOPE FOR THE PRESENT WORK

In India elevated tanks are widely used and these tanks have various types of supports.

In design of an Intze tanks for varying seismic, wind zone and the results.

Seismic effect considered in the software are based on IS codes. Due to the recent

occurrence of various earthquake zone, detailed analysis of such soil may be required

for safe design of such tanks.

In this study R.C.C. structure have been considered. The study can be extended to steel

structures.

The seismic forces remain constant in a particular Zone provided the soil properties

remain same.

NEED AND JUSTIFICATION

For regular supply of water to domestic, industrial and commercial we need to make a

storage tank.

Cracks and leakages are major problem induced in tanks, to overcome this problem we

need to design a well stable and efficient water tank.

Everytime we face the problem of low pressure at water tap to maintain the pressure

for efficient supply we need to design elevated tank.

Some elevated tank like circular water tank fail due to heavy reinforcement at bottom

to overcome this we need to design intze tank.

The main advantage of such tank are that the outward thrust from the top of conical part

resist by ring beam.

WATER DEMAND FOR VARIOUS PURPOSE (IS code 1172:1993)

Types of consumption Normal Range

(lit/capita/day)

Average %

1 Domestic Consumption 135-200 160 35

2 Industrial and

Commercial Demand

40-450 135 30

3 Public including Fire

Demand Uses

20-90 45 10

4 Losses and Waste 45-150 62 25

Water demand for various purpose in RAJKIYA ENGINEERING

COLLEGE, AZAMGARH

Types of consumption Normal Range

(lit/capita/day)

Average %

1 Offices 45-90 65 16.3

2 Laboratories

With bathroom

Without bathroom

45-90

30-60

60

45

15.11

11.3

3 Scholars

Day scholar

Hosteller

45-90

135-225

60

165

15.11

41.6

4 Canteen 2-3 2 .5

LITERATURE REVIEW

Pavan S. Ekbote and Dr. Jagadish G. Kori (2013), Elevated water tanks were profoundly

smashed or collapsed during earthquake. This was might be owing to the lack of familiarity

regarding the performance of supporting system of the water tanks against dynamic action and

also due to improper geometrical selection of staging patterns of tank. Due to the fluid structure

interactions, the seismic behaviour of elevated water tanks has the characteristics of intricate

phenomena. The main aim of this study is to understand the behaviour of supporting system

(or staging) which is more effective under different response spectrum method with SAP 2000

software. In this paper, different supporting systems such as cross and radial bracing were

studied.

R.V.R.K.Prasad and Akshaya B. Kamdi (2012), Storage elevated water tanks are used to store

water. BIS has brought out the revised version of IS 3370 (part-1&2) after a long time from its

1965 version in year 2009. This revised code is mainly drafted for the liquid storage tank. In

this revision important is that limit state method is incorporated in the water tank design. This

paper gives in brief, the theory behind the design of circular water tank using WSM and LSM.

Design of water tanks by LSM is most economical as the quantity of material required is less

as compared to WSM. Water tank is the most important container to store water therefore,

Crack width calculation of water tank is also necessary.

Asari Falguni & Prof. M.G.Vanza (2012) has thrown light on the results of an analytical

investigation of the seismic response of elevated water tanks using friction damper. In this

paper, the behaviour of RCC elevated water tank is studied with using friction damper (FD).

For FD system, the main step is to determine the slip load.

Ayazhussain M. Jabar and H. S. Patel (2012), has investigated to be aware of the deeds of

supporting system which is more effective under different earthquake time history is carried

out with SAP 2000software. As known from very upsetting experiences, elevated water tanks

were heavily damaged or collapsed during earthquake. This was might be due to the lack of

knowledge regarding the proper behaviour of supporting system of the tank again dynamic

effect and also due to improper geometrical selection of staging Patterns.

Hasan Jasim Mohammed (2011), studied 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.

IITK-GSDMA (2007), for seismic design of water tanks, IS 1893:1984 has very limited

provisions. These provisions are only for elevated water tanks and tanks resting on ground are

not considered. Even for elevated water tanks, effect of sloshing effect of vibration are not

included in IS 1893:1984. Moreover, compared with the present international practice for

seismic design of water tanks, there are many limitations in the provisions of IS 1893:1984.

Thus, one finds that at present in India there is no proper Standard for seismic design of water

tanks. In view of non-availability of a Proper Standard on seismic design of water tanks, present

Guidelines is prepared to help designers for seismic design of water tanks. This Guidelines is

written in a format very similar to that of IS code and in future, BIS may as well consider

adopting it as IS 1893 (Part 2).

O. R. Jaiswal et al, (2006), In this research paper, provisions of ten seismic codes on water

tanks are reviewed and compared. This review has revealed that there are significant

differences among these codes on designing of seismic forces for various types of water tanks.

Reasons for these differences are critically examined and the need for a unified approach for

seismic design of liquid storage tanks is highlighted.

Durgesh C. Rai and Bhumika Singh (2004), studied Reinforced concrete pedestal (circular,

hollow shaft type supports) are popular choice for elevated tanks for the ease of Construction

and the more solid form it provides compared to framed construction. In the recent past Indian

earthquakes, Gujarat (2001) and Jabalpur (1997), thin shells (150 to 200 mm) of concrete

pedestals have performed unsatisfactorily when great many developed circumferential tension

flexural cracks in the pedestal near the base and a few collapsed.

Durgesh C Rai (2003), describes about the performance of elevated tanks in Bhuj earthquake

of January 26th 2001. The current designs of supporting structures of elevated water tanks are

extremely vulnerable under lateral forces due to an earthquake and the Bhuj earthquake

provided another illustration when a great many water tank staging's suffered damage and a

few collapsed.

MATERIALS AND METHOD USED

We know that water is essential for every living thing and ground source of water are not easily

available so water is stored in various type tank so for designing of tank required better

serviceability.

Dynamic analysis of liquid containing tank is a complex problem involving fluid-structure

interaction. Based on numerous analytical, numerical and experimental studies simple spring

mass models of tank-liquid system have been developed to evaluate hydrodynamic forces.

Concrete mix weaker than M-20 is not used because of higher grade lesser porosity of

concrete.

Minimum quantity of cement in concrete shall be not less than 30 KN/m3.

Use of small size bars.

Coefficient of expansion due to temperature=11×10-6/˚C

Coefficient of shrinkage may be taken = 450 × 10-6 for initial and 200 × 10-6 for drying

shrinkage.

Minimum cover to all reinforcement should be 20 mm or the diameter of main bar

whichever is greater.

An overhead liquid retaining structure is design using WORKING STRESS METHOD

avoiding the cracking in the tank and to prevent the leakage and the component of tank

can be design using LIMIT STATE METHOD (example:-column ,foundation ,bracing

,stairs etc.).

Code using IS: 3370-PART 2-2009

IS: 456:2000

The leakage is more with higher liquid head and it has been observed that water head

up to 15m does not cause leakage problem.

In order to minimize cracking due to shrinkage and temperature, minimum

reinforcement is recommended as-

For thickness ≤ 100 mm = 0.3%

For thickness ≥ 450 mm = 0.2%

For thickness between 100 mm to 450 mm = varies linearly from 0.3% to 0.2%

For concrete thickness ≥ 225 mm, two layer of reinforcement be placed one near water

face and other away from water face.

SOFTWARE USED

AUTO CAD: AutoCAD is a commercial computer-aided design (CAD) and drafting software

application. Developed and marketed by Autodesk, AutoCAD was first released in December

1982 as a desktop app running on microcomputers with internal graphics controllers. Prior to

the introduction of AutoCAD, most commercial CAD programs ran on mainframe

computers or minicomputers, with each CAD operator (user) working at a separate graphics

terminal.Since 2010, AutoCAD was released as a mobile- and web app as well, marketed as

AutoCAD 360.

REFERENCES

IS code 1172:1993 for various water demand.

IS code 456:2000 for Concrete.

IS code 800:2007 for steel.

IS 872 part i and part ii.

IS 3373 (part iv-1967).

Journal of engineering, computers & applied sciences (jec&as) issn no: 2319-5606

volume 2, no.8, august 2013

Prof.R.V.R.K.Prasad, Akshaya B.Kamdi / international journal of engineering research

and applications (ijera) issn: 2248-9622 www.ijera.com vol. 2, issue 5, september-

october 2012, pp.664-666

International journal of advanced engineering research and studies e-issn2249–8974

ijaers/vol. i/ issue iii/april-june, 2012/325-328

Hasan Jasim mohammed.”Economical design of water concrete tanks”,europian

journal publication,vol.49 No.4(2011) pp510-520

IITK-GSDMA guidelines for seismic design of liquid storage tanks provisions with

commentary and explanatory examples.

Rai, D. C. (2005), IITK-GSDMA Guidelines on Structural Use of Reinforced Masonry,

Provisions with Commentary and Explanatory Examples, IIT Kanpur and Gujarat State

Disaster Mitigation Authority, Gandhinagar, Available at www.nicee.org/IITK-

GSDMA_Codes.php, Final Draft, 69 p.

.