Effect of Different Foundation Systems on Response ... that isolated footing has higher value of...

IJSRD - International Journal for Scientific Research & Development| Vol. 4, Issue 03, 2016 | ISSN (online): 2321-0613

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Effect of Different Foundation Systems on Response Reduction Factor of

R.C.C Frame Type Staging using Non-Linear Static Push-Over Analysis Gajera Jatin H1 Prof. Modi Poonam I2 Pancholi Vasu V3

1P.G. Student 2Assistant Professor 3Senior Geologist 1,2L.D. College of engineering, Ahmedabad 3Institute of Seismological Research, Gandhinagar

Abstract— Role of Response reduction factor in seismic

design of EWT is important, thus effect of different

foundation system on soil-structure interaction of R.C.C

frame staging water tank is carried out for find out effect of

soil-flexibility on response reduction factor. For this purpose

elevated water tank of storing capacity of 1000 m3 with

different filled conditions, different foundation systems (raft,

isolated), soil data of different location of Ahmedabad

metropolitan city with help of institute of seismological

research (ISR). RC water tank is analyzed using

displacement controlled non-linear static pushover analysis

to evaluate response reduction factor as per ATC-19 with and

without considering soil-flexibility. Three different types of

soil conditions representatives of hard soil, medium soil and

soft soil has been considered in this study. So aim of study is

to find out response reduction factors for different soil

conditions with different type of foundation systems. Study

reveals that isolated footing has higher value of response

reduction factor compare to raft foundation.

Key words: Raft foundation, Isolated Footing, Elevated

Tank, Earthquake Response, Nonlinear Analysis, Soil–

Structure Interaction, Response Modification Factor

I. INTRODUCTION

Indian sub- continent is highly vulnerable to natural

disasters like earthquake, draughts, floods, cyclones etc.

These natural calamities are causing many casualties and

innumerable property loss every year. Water supply is a life

line facility that must remain functional following disaster.

Most municipalities in India have water supply system

which depends on elevated water tanks for storage. Elevated

water tank is a large elevated water storage container

constructed for the purpose of holding a water supply at a

height sufficient to pressurize a water distribution system.

These structures have a configuration that is especially

vulnerable to horizontal forces like earthquake due to the

large total mass concentrated at the top of slender supporting

structure. So it is important to check the severity of these

forces for particular region.

These structures has large mass concentrated at the

top of slender supporting structure hence these structure are

especially vulnerable to horizontal forces due to

earthquakes. All over the world, the elevated water tanks

were collapsed or heavily damaged during the earthquakes

because of unsuitable design of supporting system or wrong

selection of sup-porting system and underestimated demand

or overestimated strength. Gareane A. I, S. A. Osman &

O.A. Karim discussed the soil and water behavior of

elevated concrete water tank under seismic load, and

concluded that a significant effect obtained in shear force,

overturning moment and axial force at the base of elevated

water tank. Dr. Suchita Hirde & Dr. Manoj Hedaoo

discussed the seismic performance of elevated water tanks

for various Zones of India for various heights and capacity

of tanks for different soil conditions. The effect of height of

water tank, earthquake Zones and soil condition on

earthquake forces are discussed and finally concluded that

the seismic forces are increases with Zones and decreases

with height of supporting system, seismic forces are higher

in soft soil than medium soil, higher in medium soil than

hard soil. Earthquake forces for soft soil is about 40-41%

greater than that of hard soil for all earthquake Zones. IITK-

GSDMA [1] discussed the guidelines for seismic design of

liquid storage tanks. Is: 3370 (Part-II) [2] discussed the

criteria for earthquake resistant design of structure. IS

1893(Part-I): 2002 [3] discussed the criteria for earthquake

resistant design of structure. The value of Response

Reduction Factor mentioned in the code of practice IS:

1893:2009(Part-2) [4] “Criteria for Earthquake resistant

design of Structures:- Liquid retaining tanks", does not

consider the varying soil conditions and effect of foundation

system. Considering effect of soil-foundation interaction,

response reduction factors will changes due to response of

structure different with respect to fixed base conditions. So

aim of study is to find out response reduction factors for

different soil & foundation conditions.

The study presented here is been carried out for the

Reinforced Concrete Intze Type Elevated Water Tank of

storing capacity of 1000 m3. The effect of the Soil structure

interaction of this structure is analyzed using FEM Software

SAP2000 [5]. The Soil data that has been used for studying

the SSI, has been provided by Institute of Seismological

Research (ISR). The variations that have been included for

the study are as below:

Varying foundation conditions of the ESR i.e. Fixed

base, isolated footing and raft foundation.

Different water level conditions of the tank i.e. Empty,

Half and Full condition.

Different types of soil conditions for different locations

of Ahmedabad city.

II. CONCEPT OF RESPONSE REDUCTION FACTOR

Response reduction factor plays important role in seismic

design of ESR, which is dependent on three parameters

over-strength, redundancy and ductility. The response

reduction factor or force modification factor R reflects the

capacity of structure to dissipate energy through inelastic

behavior. It is a combined effect of over-strength, ductility

and redundancy represented as

R=Ωo*RR*Rμ. ………….(1)

Over strength factor (Ωo) accounts for the yielding

of a structure at load higher than the design load due to

various partial safety factors, strain hardening, oversized

members, confinement of concrete. Non-structural elements

also contribute to the over strength. Ductility factor (Rμ) is a

ratio of ultimate displacement or code specified permissible

displacement to the yield displacement. Higher ductility

implies that the structure can withstand stronger shaking

Effect of Different Foundation Systems on Response Reduction Factor of R.C.C Frame Type Staging using Non-Linear Static Push-Over Analysis

(IJSRD/Vol. 4/Issue 03/2016/234)


without collapse. Redundancy factor (RR) depends on the

number of vertical framing participate in seismic resistance.

The change in R factor will be in accordance with its key

components as shown in figure 1

Fig. 1: Definition of seismic response factors on a typical

pushover curve,[6]

R as per international standards for elevated tanks: [7]

IBC 2000 / FEMA 368 - R = 1.5 to 3.0

AWWA D110 - Rc = 1, Ri = 2 to 2.75

ACI 350.3 - R = 2.0 to 4.75

IS:1893 – 2002 (part – 2)

RCC shaft support - R = 1.8

RCC frame support - R = 2.5

III. APPROACHES FOR SOIL-FOUNDATION-STRUCTURE

INTERACTION

A. Spring Base or Cone Model (Sub Structure) Approach

for Raft Foundation

In a dynamic soil–structure-interaction analysis a bounded

structure (which may be linear or nonlinear), consisting of

the actual structure and an adjacent irregular soil if present,

will interact with the unbounded (infinite or semi-infinite)

soil which is assumed to be linear elastic as shown in Fig.

2..A cone model has been proposed by Meek and Wolf [8,9]

for evaluating the dynamic stiffness and effective input

motion of a foundation on the ground is used and static

stiffness of this truncated cone (Fig.2) for circular rigid

foundation can be calculated with equations given in Table

I. Where, G: Shear modulus, r0: Radius of circular

foundation, ϑ: Poisson ratio, KV, KH, KR and KT are the

vertical, horizontal, rocking and torsional stiffness,

respectively. In Fig.3 Kx and Kh represent the translation and

rocking stiffness of foundation that can be modeled with

spring. These are attached to the central point of the rigid

circular foundation. Stiffness is calculated for individual

layers and then equivalent stiffness calculated using Bowel’s

weighted approach as shown below Eqs. (2) and (3)

…....(2)

….(3)

Stiffness no

embedment

Foundation with

embedment

Vertical

(Kv )

4𝐺𝑟

1– ϑ

4Gr

1 – υ(1 + .54

𝑒

𝑟) (1 + (. 85 − .28

𝑒

𝑟))

Horizontal

(KH )

8𝐺𝑟

2– ϑ

8𝐺𝑟

2 − ϑ(1 + .54

𝑒

𝑟)

Rocking

(KR )

8𝐺𝑟3

3(1– ϑ)

8𝐺𝑟3

3(1 − ϑ)[1 + 2.3

𝑒

𝑟+ .58 (

𝑒

𝑟)

3

]

Torsional

(KT )

16𝐺𝑟3

3

16𝐺𝑟3

3(1 + 2.67

𝑒

𝑟)

Table 1: Static Stiffness Values of Rigid Circular

Foundation, [10]

Where G: shear modulus, r: radius of a circular

foundation, υ: poisson ratio, e: embedment height

Fig. 2: Cone for various degree of freedom with

corresponding apex ratio, wave propagation velocity and

distortion.[11]

Fig. 3: Spring base Model

B. Spring Base FEMA 356 (Sub Structure) Approach for

Isolated Foundation

For soil-structure interaction of shallow isolated footing, SSI

approach given in FEMA356 [12] is used. In this approach

size of isolated footing is find out and corresponding to

footing size static soil spring stiffness find out equation

given in fig 4,5. In which fig 4 shows value of soil spring

stiffness footing rest on ground while in fig 5 correction

factor for embedment of footing is given. For each isolated

footing six equivalent soil spring stiffness three translation&




three rocking spring stiffness in X, Y, Z directions are

calculated.

Fig. 4: Stiffness of rigid isolated footing resting on surface.

Fig. 5: Stiffness of rigid isolated footing at depth h below

the surface.

C. Description of Subsoil Data

A study considered different three sites of Ahmedabad city

location selected as per soil classification given in IS

1893:2002 soil data selected as soft medium and hard soil

based on SPT N-value, soil data collected with help of

institute of seismological research, Gandhinagar. From soil

characteristic and shear wave velocity basic soil properties

find out with help of some imperial formulas. For the

analysis and available soil data such as number of layers of

soil, thickness of each layer, unit weight, and shear modulus

are obtained from borehole data and geophysical testing.

The soil characteristics can be calculated with well-

known equations G = E/2(1- ϑ) and Vs = G/ρ2; where, ϑ:

poisons ratio, E: Modulus of elasticity of soil layer, ρ: is the

mass density, and G is the shear modulus, Vs: Shear wave

velocity of soil layer, which is shown in Table III.

According to soil bearing capacity size and depth of footing

and thickness of raft is selected which is shown in Table II.

Type of

soil

S.B.C

(KN/m3)

Size of

raft (m)

Depth of

footing

(m)

Thickne

ss of

raft (m)

Soft 80 8 3 2

Medium 150 6.5 3 2

Hard 280 5.5 3 2

Table 2: Description of raft foundation for different soil

condition

Soil

type

Footing

ID

S.B.C

(KN/m3)

Size of footing

L B Thickness

of footing

Hard A&B

280 3.5 3.5 1.2

C 10 3.5 1.2

Medium A&B

150 4.5 4.5 1.5

C 14 4.5 1.5

Soft A&B

80 6 6 1.5

C 13 8 1.5

Table 3: Details of different types isolated footing, size, and

thickness of footings.

From the soil characteristics stiffness of foundation

should be find out with help of cone model for raft

foundation which is discussed above and different

directional spring stiffness find out with help of give

equations in table I, which is shown in table 4 as below.

Same procedure is carried out for isolated footing as per

FEMA 356. For that equation given in fig 4,5 is used and

from that equivalent soil spring stiffness is find out as

shown in table 5.

Depth (m) IS

Classification

Bulk Density

(KN/m3)

Shear Wave

Velocity(m/s)

Shear Modulus

Gmax

Poisons

Ratio

Modulus of

Elasticity E

1.5 CL 15.23 322.09 1579995 0.43 4518786

3.0 ML 14.88 372.46 2064031 0.3 5366481

4.5 MI 13.91 445.21 2756518 0.3 7166945

6.0 SM 17 445.21 3369131 0.3 8759740

7.5 SM 16.12 554.34 4952123 0.3 12875519

9.0 SM 17.56 554.34 5395065 0.3 14027169

10.5 SM 17.56 563.5 5574951 0.3 14494872

12.0 MI 16.45 563.5 5224915 0.33 13898273

13.5 MI 16.15 614.92 6107359 0.33 16245574

15.0 MI 14.16 614.92 5355517 0.33 14245675

18.0 SC 14.75 614.92 5575546 0.3 14496419

19.5 MI 14.41 535.4 4130471 0.33 10987051

21.0 SM 14.88 535.4 4265710 0.3 11090845

22.5 GC 13.97 614.92 5282318 0.2 12677563

24.0 MI 14.92 614.92 5643317 0.33 15011224

25.5 SM 13.6 614.92 5143701 0.3 13373623

27.0 SM 17.87 614.92 6756407 0.3 13373623

28.5 CI 16.06 563.5 5098677 0.43 14582216

30.0 CI 16.63 563.5 5279947 0.43 15100647

Table 4: Characteristics Properties of Hard Soil at Ahmedabad City




Type of Soil Bore Hole id Kv = Kh= KR= KT=

Soft BH-01 332268683 156734053 9428938381 13381867838

BH-16 486939919 231897775 13818113860 19887549289

Medium BH-02 345986204 160137555 6752141698 9117293854

BH-09 337156384 154336403 6579822116 8741720386

Hard BH-04 244139039 112297282 3542763456 4651910721

BH-06 298394678 143810967 4330080789 6119785286

Table 5: Static Spring Stiffness For Rigid Raft Embedded At 1m Depth for Different Type Of Soil As Per Cone Model [8,9]

Soil type Hard Hard

Bore hole id BH-06 BH-04 BH-06 BH-04

Footing ID A & B A & B C C

Kx= 100531118 92176653 135147952 123916715

Ky= 100531118 92176653 147812644 135528930

Kz= 77506403 73514902 126513573 119998253

Kxx= 1159008759 1099320984 1511437908 1433600390

Kyy= 374987427 355675955 2713579445 2573832857

Kzz= 595856630 536562896 3345650026 3012724166

Soil type Medium Medium



Kx= 118999448 133338259 167061165 187191162

Ky= 118999448 133338259 184037417 206212962

Kz= 97844487 108054750 168486789 186068714

Kxx= 2486021381 2745442558 3335521536 3683589710

Kyy= 772287961 852877715 6849666671 7564442740

Kzz= 1176586676 1327964339 7956467017 8980132680

Soil type Soft Soft



Kx= 118762818 175028007 164809344 242920881

Ky= 118762818 175028007 171838558 253281598

Kz= 99160538 144696895 156819666 228964612

Kxx= 3979674493 5846304691 8862276739 13001173220

Kyy= 1245018308 1817392651 6793783140 9925928651

Kzz= 2057958496 3049707251 8178133239 12119249384

Table 6: Static Spring Stiffness for Isolated Footing Embedded At 1m Depth For Different Soil As Per Fema 356[12]

IV. DESCRIPTION OF MODEL

An intze type reinforced elevated water tank of 1000 m3

storage capacity with their full, half and empty water level

in the container has been considered for the present study.

Columns are arranged on the periphery of staging and

connected with three bracing levels. Other dimensions of the

elevated tanks are illustrated in Table 6. Finite element

model of elevated water tank is prepared and analyzed in

SAP2000. For push-over analysis actual design and

detailing is carried out with help of excel sheet, which is

illustrated in table 7.

Description Dimensions

Capacity of the tank (m3) 1000

Unit weight of concrete (kN/m3) 25

Thickness of Top Dome(m) 0.15

Rise of Top Dome (m) 2.2

Size of Top Ring Beam (m) 0.35× 0.35

Diameter of tank (m) 13.6

Height of Cylindrical wall (m) 6.8

Thickness of Cylindrical wall (m) 0.345

Size of Middle Ring Beam (m) 1.2× 0.6

Rise of Conical dome (m) 2.35

Thickness of Conical shell (m) 0.5

Rise of Bottom dome (m) 1.6

Thickness of Bottom dome shell (m) 0.2

Size of Bottom Ring Beam (m) 1.2 × 1.2

Distance between intermediate bracing (m) 4

Height of Staging above Foundation (m) 16

Number of Columns (circular) 8

Number of Bracings Level 4

Diameter of Columns (m) 0.8

Size of main Bracing (m) 0.5 × 0.5

Table 6: Structural Data for Basic Frame Type Staging

Columns and bracings in the frame type support

system are modelled as frame elements (with six degrees of

freedom per node). Conical part, bottom and top domes and

container walls are modelled with thin shell elements (with

four nodes and six degrees of freedom per node). Degrees of

freedom were fixed at the base nodes and left free at the

others for the one called fixed-base system. Spring base

system for raft & isolated foundation has been developed by

applying translational and rocking spring as shown in table

5,6.




Component Dimensions

(mm)

Main

Steel

Distribution

Steel

Top Dome 150

10φ

@100mm

c/c

10φ @

100mm c/c

Top ring

beam 350*350 12 φ 6 no

8 φ 2legged @

300mm c/c

Cylindrical

wall 345 Hoop ring -

2m from top

10 φ @

340mm c/c

10 φ @

260mm c/c

4m from top

12 φ @

240mm c/c

10 φ @

170mm c/c

6m from top

16 φ @

220mm c/c

10 φ @

130mm c/c

Middle Ring

Beam 1200*600

20 φ 14

no

10 φ @150mm

c/c

Conical

dome 500

25 φ @

280mm c/c

10 φ@

110mm c/c

Bottom ring

beam 1200*1200

16 φ 7 no

top

12 φ 4 legged

@160 mm c/c

25 φ 6 no

bottom

8 φ 2 legged

@ 110mm c/c

Bottom

dome 200

10 φ @

120mm c/c

10 φ @

120mm c/c

bracings 500*500 16 φ 7 no 10 φ 2 legged

@ 300mm c/c

Column 900 32 φ 8 no 10 φ 2 legged

@ 150 mm c/c

Raft beam 850*900 16 φ 14 no

top

12 φ 4 legged

130mm c/c

16 φ 7 no

top

Raft slab 250 25 φ @

300mm c/c

12 φ @

230mm c/c

Table 7: Reinforcement Detailing of Frame Type Elevated

Water Tank

V. PUSH-OVER ANALYSIS METHOD

The procedure of performing the pushover analysis in this

study is adapted from FEMA 273 [13]. First, the gravity

loads including weights of tank, stored water, pedestal wall

and other equipment’s is applied to the FE model. Next a

gradually increasing lateral load is applied to the model until

the structure collapses. Since most of the weight in an

elevated water tank is concentrated in the tank and that the

modal mass participation factor based on modal analysis of

the first mode is above 90%, the lateral load is applied with

a load pattern similar to the first (fundamental) mode shape.

For push-over analysis hinges properties like Moment-

rotation (M-φ) and Axial load – Bending Moment (P-M)

relationships for flexural and compression members have

been developed using Xtract’s software. After assigning

hinge properties to the structure, the static pushover cases

were defined. Typically, the gravity loads were applied first

and then subsequent lateral static pushover load cases were

specified to start from the final conditions of the gravity

pushover. In the gravity case, the structure was loaded with

the dead load and 25% of the live load. The application of

gravity loads was force-controlled whereas the application

of lateral loads was displacement-controlled. The first mode

response of the structure was assigned as the load pattern for

the lateral push applied to the structure. The procedure

involves applying horizontal loads, in a prescribed pattern,

to a computer model of the structure, incrementally

The nonlinear static procedure requires prior

estimation of target displacement. The target displacement

serves as an estimate of the maximum displacement of the

selected point (node) in the subject structure during the

design earthquake. The node associated with the center of

mass at CG of container is often the target point or target

node selected for comparison with target displacement. The

maximum limit for the roof displacement is specified as

0.004H, where H is the height of the structure.[14]

A. Bilinear Approximation of Pushover Curves

In order to extract meaningful and practical information, it is

often required to develop an equivalent bilinear

approximation of pushover curve. The maximum base shear

(Vmax) is defined as the maximum base shear developed in

the structure prior to onset of stiffness degradation as shown

in Fig. 5. Unlike Vmax, defining Δmax requires judgment and

depends on the structure type and its occupancy. Generally,

Δmax might be defined in a way to account for post-peak

deformation. This is shown in Fig. 5 as Δultimate which

denotes the deformation of the structure after a certain

reduction in the stiffness. Due to the nonlinear

characteristics of reinforced concrete structures, which

involves cracking and crushing of concrete as well as

yielding of steel, determining the global yield displacement

(Δy) is a complicated task.[15]

Fig. 7: Bilinear idealization of pushover curves.[16]

Fig. 8: bilinear idealization of push-over curve as per FEMA

273 in SAP2000.




VI. RESULTS OF SEISMIC RESPONSE REDUCTION FACTOR

Non-linear static push-over analysis of above descripted

model considering soil-structure interaction with different

foundation systems is carried out, form this analysis bi-

linearization of push-over curve as per FEMA 273. Form

this curve seismic response reduction factors as per ATC-19

[17] is find-out. Following Table VIII is represent the

seismic response factors time period, over-strength factor &

ductility factor.

Base Condition Soil Condition Tank Filled Condition T Ω Rµ R

Fixed Based

Hard

Empty 0.9095 4.785 2.486 10.23

Half 1.1569 2.329 4.039 8.09

Full 1.5016 2.11 3.475 6.326

Medium

Empty 0.9095 2.404 3.971 8.198

Half 1.1569 3.1 2.422 6.469

Full 1.5016 2.031 2.769 4.834

Soft

Empty 0.9095 2.458 3.266 6.903

Half 1.1569 2.14 2.822 5.208

Full 1.5016 1.677 2.67 3.18

Spring Based

Hard Empty 0.9584 3.69 3.098 9.852

BH-06 Half 1.2177 2.911 3.4 8.519

Full 1.4298 2.96 3.3 8.4

medium Empty 0.9578 3.2 2.571 7.075

BH-09 Half 1.2168 2.618 2.639 5.942

Full 1.4298 2.265 2.522 4.912

soft Empty 0.9574 2.339 2.996 6.028

BH-01 Half 1.2163 2.288 2.332 4.588

Full 1.4292 1.675 2.545 3.667

hard Empty 0.9584 3.7 3.06 9.766

BH-04 Half 1.2177 2.954 3.311 8.411

Full 1.4314 2.55 3.34 7.295

medium Empty 0.958 2.26 4.02 7.834

BH-02 Half 1.2168 2.152 3.365 6.229

Full 1.43 1.9 3.29 5.4

soft Empty 0.957 2.98 2.467 6.332

BH-16 Half 1.215 2.384 2.349 4.815

Full 1.4286 1.8 2.394 3.726

Isolated

Foot

ing

hard Empty 0.9989 3.107 3.628 9.695

BH-06 Half 1.2753 2.513 3.772 8.15

Full 1.5019 2.143 3.844 7.08

hard Empty 0.9989 3.1 3.668 9.8

BH-04 Half 1.2753 2.521 3.744 8.11

Full 1.5019 2.156 3.81 7.04

medium Empty 0.9094 2.69 3.511 8.13

BH-09 Half 1.1569 2.353 3.237 6.55

Full 1.36 2.17 2.91 5.45

medium Empty 0.9094 2.69 3.56 8.199

BH-02 Half 1.157 2.354 3.28 6.64

Full 1.3602 2.17 2.93 5.51

soft Empty 0.9094 2.44 3.27 6.85

BH-01 Half 1.1569 2.15 2.8 5.18

Full 1.3602 1.94 2.43 4.05

soft Empty 0.9094 2.44 3.27 6.85

BH-16 Half 1.1569 2.15 2.805 5.17

Full 1.3602 1.935 2.41 4.02

Table 8: Results of Seismic Response Reduction Factor and Time Periods with Different Soil, Foundation And Water Level

in Tank




Fig. 9: Response reduction factor for hard soil, different

foundation and tank fillied conditions.

Fig. 10: Response reduction factor for medium soil,

different foundation and tank fillied conditions.

Fig. 11: Response reduction factor for soft soil, different


Fig. 12: Over-Strength Factor Hard Soil, Different

Foundation and Tank Fillied Conditions

Fig. 13: Over-strength factor medium soil, different


Fig. 14: Over-strength factor soft soil, different foundation

and tank fillied conditions

VII. CONCLUSION

From the soil-structure analysis considering different

foundation systems, using non-linear static push-over

analysis to finding out of seismic response factor as per

ATC-19 given in table 8. Which leads to following

conclusions.

Response reduction factor in fixed condition is less

compare to different foundation with SSI approach.

Value of R is higher in raft type foundation compare to

isolated footing for hard soil.

For medium & soft soil, response reduction factor is

lower in case of raft foundation with respect to isolated

footing.

Over strength factor is higher in different SSI approach

compare to fixed based condition.

Over strength factor has higher value for raft

foundation in all soil conditions.

From this study it is conclude that effect of

different foundation is shown in response reduction factor.

For detail study more soil data & different structure should

be taken in consideration.

REFERENCES

[1] IITK-GSDMA guidelines (2007), “Seismic design of

liquid storage tanks, provisions with commentary and

explanatory examples”.

[2] IS 3370 (Part I) : 2009, “Code of practice for concrete

structures for the storage of liquids part II reinforced

concrete structures”, Bureau of Indian Standards, New

Delhi.

[3] I.S 1893:2002, “Criteria for earthquake resistant design

of structures”, Bureau of Indian Standards, New Delhi.




[4] I.S 1893:1984(part:-2), “Criteria for earthquake

resistant design of structures”, Bureau of Indian

Standards, New Delhi.

[5] ‘Structural Analysis Program SAP2000.’ User’s

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Calif.

[6] Vishva K. Shastri, Jignesh A. Amin,(2015), “effects of

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rc water tank”, International Journal of Advance

Engineering and Research Development Volume

2,Issue 6, June -2015.

[7] Tejash Patel, Jignesh Amin, Bhavin Patel,(2014),

“Evaluation response reduction factor of RC framed

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analysis”, international journal of civil and structural

engineering volume 4, no 3, 2014.

[8] Wolf, J.P. (1994) “Foundation vibration Analysis

Using Simple Physical Models Prentice-Hall”,

Englewood Cliffs

[9] Wolf, J.P.(2002). Some Cornerstones of Dynamic Soil–

Structure Interaction, Engineering Structures , 24, 13-28

[10] Livaoglu, ssssR., Dogangun, A. (2007). Effects of

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Engineering, 27, 855-863

[11] Chirag N. Patel and H. S. Patel, (2014), “Soil-

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International Conference on Advances in Tribology and

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[12] Federal Emergency Management Agency, FEMA 356,

(2000) “Prestandard and commentary for the seismic

rehabilitation of buildings” Washington, D.C.

[13] Federal Emergency Management Agency, FEMA 273-

274, (1996) “NEHRP guidelines for the seismic

rehabilitation of buildings”, Washington, D.C.

[14] Preliminary Draft code IS 11682:1985, “Criteria for

Design of RCC Staging for Overhead Water Tanks”,

Bureau of Indian Standards, New Delhi, June 2011.

[15] R. Ghateh , M.R. Kianoush , W. Pogorzelski(2015),

“Seismic response factors of reinforced concrete

pedestal in elevated water tanks”, ELSEVIER

Engineering Structures 87 (2015) 32–46.

[16] Mostafa Masoudi , Sassan Eshghi , Mohsen Ghafory-

Ashtiany,(2012), “Evaluation of response modification

factor (R) of elevated concrete tanks”, ELSEVIRE

Engineering Structures 39 (2012) 199–209.

[17] Applied Technology Council, ATC-19 (1995)

“Structural response modification factors”, Redwood

City, California

[18] Applied Technology Council, ATC-40 (1996) “Seismic

evaluation and retrofit of concrete buildings”, vol

1.Redwood City, California

[19] IS 456:2000, “Plain and Reinforced Concrete, Code of

Practice”, Bureau of Indian Standards, New Delhi.

[20] IS 3370 (Part II): 1965, “Code of practice for concrete

structures for the storage of liquids part II reinforced

concrete structures”. Bureau of Indian Standards, New

Delhi.

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