Dynamic Analysis of Liquid Storage Tanks with Sliding Systems

Abstract

Dynamic response of liquid storage tanks isolated by the sliding systems is investigated under real earthquake ground motion. The frictional force of sliding systems is modelled by conventional and hysteretic models. The continuous liquid mass is lumped as convective mass, impulsive mass and rigid mass. The corresponding stiffness associated with these lumped masses is worked out depending upon the properties of the tank wall and liquid mass. The governing equations of motion of the tank with sliding system are derived and solved by Newmark's step-by-step method with iterations. The frictional force mobilized at the interface of the sliding system is assumed to be velocity dependent. For comparative study, the seismic response of isolated liquid storage tank obtained by the conventional model is compared with the corresponding response obtained by the hysteretic model. In order to measure the effectiveness of isolation system, the seismic response of isolated tank is compared with that of the non-isolated tank. A parametric study is also conducted to study the effects of aspect ratio of tank on the effectiveness of seismic isolation of liquid storage tanks. It is found that the sliding systems are quite effective in reducing the earthquake response of liquid storage tanks. In addition, the conventional and the hysteretic model of the sliding system predict the same seismic response of liquid storage tanks. However, the conventional model is relatively more computationally efficient as compared to the hysteretic model.

Keywords

liquid storage tank base isolation sliding systems seismic response conventional model hysteretic model aspect ratio

Get full access to this article

View all access options for this article.

References

Chalhoub

M.S.

and Kelly

J.M.

(1990). “Shake table test of cylindrical water tank in base isolated structures”, Journal of Engineering Mechanics, ASCE, Vol. 116, pp. 1451–1472.

Constantinou

M.C.

Mokha

A.S.

and Reinhorn

A.M.

(1990). “Teflon bearing in base isolation II: Modelling”, Journal of Structural Engineering, ASCE, Vol. 116, pp. 455–474.

Fan

F.G.

and Ahmadi

(1990). “Multi-storey base-isolated buildings under a harmonic ground motion – Part II: A comparison of various systems”, Nuclear Engineering and Design, Vol. 123, pp. 14–26.

Gueraud

Noel-Leroux

J.-P.

Livolant

and Michalopoulos

A.P.

(1985). “Seismic isolation using sliding elastomer bearing pads”, Nuclear Engineering and Design, Vol. 84, pp. 363–377.

Haroun

M.A.

(1983). “Vibration studies and test of liquid storage tanks”, Earthquake Engineering and Structural Dynamics, Vol. 11, pp. 179–206.

Iura

Matushi

and Kosaka

(1992). “Analytical expressions for three different modes in harmonic motion of sliding structures”, Earthquake Engineering and Structural Dynamics, Vol. 21, pp. 757–769.

Jangid

R.S.

and Datta

T.K.

(1995a). “Seismic behaviour of base isolated building – A-state-of-the-art-review”, Structures and Buildings, Vol. 110, pp. 186–203.

Jangid

R.S.

and Datta

T.K.

(1995b). “Performance of base isolation systems for asymmetric building to random excitation”, Engineering Structures, Vol. 17, pp. 443–454.

Jangid

R.S.

(1996). “Seismic response of sliding structures to bi-directional earthquake excitation”, Earthquake Engineering and Structural Dynamics, Vol. 25, pp. 1301–1306.

10.

Jangid

R.S.

(1997). “Response of pure-friction sliding structures to bi-directional harmonic ground motion”, Engineering Structures, Vol. 19, pp. 97–104.

11.

Jangid

R.S.

and Londhe

Y.B.

(1998). “Effectiveness of elliptical rolling rods for base-isolation”, Journal of Structural Engineering, ASCE, Vol. 124, pp. 469–472.

12.

Kelly

J.M.

(1986). “A seismic base isolation: Review and bibliography”, Soil dynamics and Earthquake Engineering, Vol. 5, pp. 202–216.

13.

Kim

N.S.

and Lee

D.G.

(1995). “Pseudo-dynamic test for evaluation of seismic performance of base-isolated liquid storage tanks”, Engineering Structures, Vol. 17, pp. 198–208.

14.

Malhotra

P.K.

(1997). “New methods for seismic isolation of liquid-storage tanks”, Earthquake Engineering and Structural Dynamics, Vol. 26, pp. 839–847.

15.

Mokha

Constantinou

M.C.

and Reinhorn

A.M.

(1990). “Teflon bearings in base isolation I: Testing”, Journal of Structural Engineering, ASCE, Vol. 116, pp. 438–454.

16.

Mostaghel

and Tanbakuchi

(1983). “Response of sliding structures to earthquake support motion”, Earthquake Engineering and Structural Dynamics, Vol. 11, pp. 729–748.

17.

Mostaghel

and Khodaverdian

(1987). “Dynamics of resilient-friction base isolator (R-FBI)”, Earthquake Engineering and Structural Dynamics, Vol. 15, pp. 379–390.

18.

Rao

P.B.

and Jangid

R.S.

(2001). “Performance of sliding systems under near-fault motions”, Nuclear Engineering and Design, Vol. 203, pp. 259–272.

19.

Shrimali

M.K.

and Jangid

R.S.

(2002). “Non-linear seismic response of base-isolated liquid storage tanks to bi-directional excitation”, Nuclear Engineering and Design, Vol. 217, pp. 1–20.

20.

Wen

Y.K.

(1976). “Method of random vibration of hysteretic systems”, Journal of Engineering Mechanics, ASCE, Vol. 102, pp. 249–263.

21.

Zayas

V.A.

Low

S.S.

and Mahin

S.A.

(1990). “A simple pendulum technique for achieving seismic isolation”, Earthquake Spectra, Vol. 6, pp. 317–333.