Elevated Water Tank Under Sloshing Effect

IJSRD - International Journal for Scientific Research & Development| Vol. 4, Issue 05, 2016 | ISSN (online): 2321-0613

Elevated Water Tank under Sloshing Effect Miss. S. A. Patil1 Prof. A. H. Kumbhar2 Prof. T. F. Mujawar3 1 B.E. Student 2,3Assistant Professor 1,2,3 Department of Civil Engineering 1,2,3 Dr. Daulatrao Aher College of Engineering, Karad. MH Abstract— In day to day life, one cannot live without water.

The elevated liquid storing tank is the most effective storing competence used for domestic or even industrial rationale.

The liquid storage tank is a lifeline structure & the water tank is important for water distribution distribution system. After the earthquakes the failure of large tanks are suspected & result of dynamic buckling. The water supply is available in earthquake affected region. The aim of behavior of elevated water tank of liquid storage during the earthquake caused the overturning movements, seismically induced by slosh waves.

In this paper analysis to study the sloshing effect in elevated water storage tank.

Key words: Elevated Water Tank, Sloshing Effect, Stadpro of Earthquake Loading

Fig. 1: Analytical Model of Water Tank in STAAD Pro Software

I. INTRODUCTION The elevated water tank are normally used to store the water for dome sting and firefighting purpose. The failure of these structure may cause serious hazard for people shortage of water or difficulty putting out fires during earthquakes. The elevated water tank is a large capacity tank. The elevated water tank under sloshing effect.” Sloshing” means the movement of water in water storage tank during the earthquake. The liquid storage tank is seismically safety it is importance. During the earthquakes the elevated water tank is severally damaged. The analysis of behavior of elevated water tanks the motion of water relative to the tank & motion of tank relative to the ground. Sloshing is defined as the periodic motion of the free liquid surface in a partially filled container. The basic problem of liquid sloshing involves the estimation of hydrodynamic pressure distribution, forces moments frequency of free liquid surface. The elevated water storage tank is a structure constructed sufficient height to cover the large area for supply of water, it is easy to analyses & study the behavior of structure during earthquake. As of today water tank are analyzed and designed by considering the earthquake forces and wind forces imposed over the water tank body. The response of water tank and staging for earthquake and wind loading is different for than for static loading. When earthquake forces and wind forces are developed the resulting horizontal trust which constitute a major load is of complex nature.

Fig. 2: Bending Moment Diagram for Staging under Dead Load Condition

II. MODELLING OF WATER TANK The modeling of elevated water tank .The finite element method by using the model of elevated circular water tank.

Shape – Circular water tank supported on column, bracing staging.

1) Capacity – 4, 00,000 liters.

2) Height of staging – 16 m 3) Steel – all reinforcement shall be HYSD. 4) Water density – 9.81 KN/m3 5) Seismic zone – III 6) wind speed – 39 m/s

Fig. 3: Bending Moment Diagram for Staging under Seismic Tank Full Condition

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Elevated Water Tank under Sloshing Effect (IJSRD/Vol. 4/Issue 05/2016/024)

exposed to three pair of earthquake records have been studied and analyzed in time history using mechanical and finiteelement modeling technique. The liquid mass of tank is modeled as lumped masses known as sloshing mass, or impulsive mass.

Fig. 4: Max Von Mises Stresses in Water Tank

E. Behavior of Elevated Water Tank under Sloshing Effect M. V. Waghmare, S.N.Madhekar In this paper most of the failures of large tanks after earthquakes are suspected to have resulted from the dynamic buckling caused by overturning moments of seismically induced liquid inertia and surface slosh waves. Recent earthquakes have shown that liquid storage tanks are found to be vulnerable to damage. Current knowledge about the behavior of liquid storage tank is extensive, but many of the analytical and theoretical results are for tanks without roof systems and include number of simplifying assumptions like small deformation and linear elastic material property nonlinear conditions, sloshing heights are larger than that those calculated under linear condition. In the present study sloshing effect in elevated water tank is studied by using Finite Element Method (FEM).

III. LITERATURE REVIEW

IV. SEISMIC LOAD ON THE TANK

A. Ketan Bajaj, Jitesh T. Chavda, Bhavik M. Vyas (2013) [3] This paper studied the buildings are subjected to different earthquake loading and behaves differently with the types of condition, such as soft, medium and hard soil. Different soil properties can affect seismic waves as they pass through a soil layer. With the change in soil property from hard to medium and from hard to soft the shear force has increased by respectively for flexible base. for the primary components, namely, columns, beams, and infill walls

Translation stiffness of column is Kt  8 x

L



C. “Sloshing effect on overhead liquid storage tank” P. Muthu vijay & Amar prakash (Aug 2014) In this paper present the analysis to study the effect of sloshing in overhead liquid storage tank. In such structure a large mass concentrated at the top of slender supporting structure makes the structure vulnerable to horizontal forces e.g. due to find out the design parameter for seismic analysis and also the importance in the sloshing effect consideration during the design. Here an elevated in the type water tank is analyzed and designed.

D. “Seismic Behavior Assessment of Concrete Elevated Water Tank S. Bozorgmehrnia1*, M.M. Ranjbar2 and R. Madandoust2 In this paper dynamic behavior differs greatly comparison with other structures. In this research, a sample of reinforced concrete elevated water tank, with 900 cubic meters capacity,

3

20 X  0 . 60 

96 X 5000 X

4 

4 12

3

= 362.24 x 103 KN/M Lateral deflection caused at the top of tank due to seismic load is 

 

4xW



4xW



kt

kt

B. Coupled Tilt and Translational Ground Motion Response Spectra” Erol Kalkan and Vladimir Graizer ASCE 2007 In this paper dynamic response of structures subjected to earthquake induced base excitations are often amplified by ignoring the tilt components of ground motion. However, close to the earthquake source, tilting of the ground surface may become significant. Based on strong-motion records at the Pacoima Dam–upper left abutment obtained during the 1994 Northridge Earthquake, residual tilt reached 3.1° in the N45°E direction while the dynamic tilt remained higher.

12EI

4 x (7702.71)

kt

4 x (3302.71)





362 . 24 * 10 * 10 * 10

362 . 24 * 10 * 10 * 10

4xW 4 x (5302.71) 362 . 24 * 10 * 10 * 10

= 0.0851m =.03646m =.05855mFull = 85.051 mm Empty =36.46mm Half =58.55mm The free period of oscillation of the structure is 

T  2 x  2 x

0.0851

Empty

9.81

g

0.03646

 2 x

Half =  2 x

0.05855 9.81

9.81

Full = 0.5852 sec Empty =0.3830sec Half = 0.4854sec Considering medium soil Sa g 

1 . 36



1 . 36 T

 2 . 1625

0 . 6289

Design horizontal seismic coefficient ZI ( sa Ah 

g

)

2R

For zone III Z = 0.16 (zone factor) I = 1.5 (Importance Factor) R = Response reduction factor R = 3 ordinary moment resisting frame (OMRF) Ah = 0 . 16 x1 . 5 x 2 . 1625 2 x3

= 0.0865

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91

Elevated Water Tank under Sloshing Effect (IJSRD/Vol. 4/Issue 05/2016/024)

Base shear VB is given as VB = Ah x w = 0.0865 x (1112.89 x 8) = 770KN W(K N)

Level

220.3 9 220.3 9 220.3 9 7259.

60

1 2 3 4

Hi (M )

Wihi2

4

3526.34

wihi

2

 w : hi

2

1.69724x4x1 0-3

14105.37 6.7869x 10-3 6 31737.09 12 0.01527 6 2028953.

16 0.97924 6 Table 1: Seismic Forces 8

Later al fore(v ) (KN)

P=

1.30 5.22 11.75 754.1 2

2)

1531 . 75  11 . 09 2 x  2

    x  2 cos( 45  2)   

= 74.74KN  Total load on column due to dead load plus seismic load is Total = 8903.12 + 74.7 = 8977.82KN Bending moment on one column 4 M = (754.12 + 11.75 + 5.22 + 1.33) x x 1 8 2 = 193.10kNM e = M  193 .1  172 mm p 

1122 . 22 x10 x1 . 5

fckbd

0 0

0

0

82.253

0

0 0

0 0

82.253 82.253

0 0

V. CONCLUSION   

The sloshing of height may either increase or decrease with increase in the height of water in the tank.

Due to sloshing effect of water amplitude of vibration reduces suddenly due to damping of energy, liquid in the tank act as a liquid damper The sloshing of water not depends on volume of water in tank, it depends on staging height.

REFERENCES

 0 . 23379

20 x 600 x 600 6

Mu fckbd

5 6

23.2 2 0 0

1122 . 22 3

Pu

0

Table 3: Mass participation in percent MODE FREQUENCY(C/S) PERIOD(sec) 1 1.455 0.68736 2 1.455 0.68736 3 2.315 0.43216 4 6.547 0.15274 5 12.468 0.08021 6 12.468 0.0802 Table 4: Calculated frequency for load (DL+EQ+Water load)) MO SUM SUMM SUMM X Y Z DE M-x -Y -Z 0.0 99.

1 0 0.011 0 99.971 1 97 99.

0.0 2 0 99.982 0 99.982 97 1 3 0 0 0 99.982 0 99.982 62.

4 0 0 99.982 62.759 99.982 76 0.0 5 0 0 99.984 62.759 99.991 1 0.0 6 0 0 99.983 62.759 99.993 1 Table 5: Mass participation in percent

2078322.412 754.12 11.75 5.22 1.3 M P= 2r ( 2 cos 0

4

2



193 . 1 x10 x1 . 5 20 x 600 x 600

2

 0 . 06704

Percentage of steel = 1% Provide Ast =3600mm2 MODE FREQUENCY(C/S) PERIOD(sec) 1 12.407 0.0806 2 18.441 0.05423 3 18.441 0.05423 4 20.94 0.04776 5 23.321 0.04288 6 23.343 0.04284 Table 2: Calculated frequency for load (DL+EQ) MOD E

X

1

0

2 3

0 0

Y 59.0 3 0 0

Z

SUMMX

SUMMY

SU MM -Z

0

0

59.03

0

0 0

0 0

59.03 59.03

0 0

[1] Dr. G. Ravi, Dr. H. S. Prasanna, Vinay M. L. Gowda (December 2015) [1] [2] “Determination of Natural Frequencies and Mode Shapes of Structures Using Subspace Iteration Method with Accelerated Starting Vectors”.

[3] Ketan Bajaj, Jitesh T. Chavda, Bhavik M. Vyas (2013) [3].

[4] Dimitrios Vamvatsikos2 and C. Allin Cornell, Direct Estimation of Seismic Demand and Capacity of Multidegree-of-Freedom Systems through Incremental Dynamic Analysis of Single Degree of Freedom Approximation,ASCE3,ASCE 2005 [5] Emrah Erduran and Ahmet Yakut, Vulnerability Assessment of Reinforced Concrete Moment Resisting Frame Buildings, ASCE 2007.

[6] Erol Kalkan and Vladimir Graizer, Coupled Tilt and Translational Ground Motion Response Spectra , ASCE 2007 [7] Farrashkhalvat and J.P. Miles ,Basic Structured Grid Generationwith An Introduction To Unstructured Grid Generation , Butterworth-Heinemann, oxford,2003 [8] FFT analyzer manual

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Elevated Water Tank under Sloshing Effect (IJSRD/Vol. 4/Issue 05/2016/024)

[9] Gregory A. Kopp and David Surry, Wind Tunnel and Uniform Pressure Tests of a Standing Seam Metal Roof Model, ASCE 2005.

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