Seismic Behavior Assessment of Concrete Elevated Water Tanks

Authors

1 M.Sc., Civil Engineering Department, Guilan University, Rasht, Iran

2 Ph.D., Civil Engineering Department, Guilan University, Rasht, Iran

Abstract

Elevated tanks are very important structures and consist of various types. Water supply is vital to control fires during earthquakes. Also they are utilized to store different products, like petroleum supplies in cities and industrial zones. Damage to these structures during strong ground motions may lead to fire or other hazardous events. Elevated tanks should stay functional after and before earthquakes. However their dynamic behavior differs greatly in comparison with other structures. In this research, a sample of reinforced concrete elevated water tank, with 900 cubic meters capacity, exposed to three pair of earthquake records have been studied and analyzed in time history using mechanical and finite-element modeling technique. The liquid mass of tank is modeled as lumped masses known as sloshing mass, or impulsive mass. The corresponding stiffness constants associated with these lumped masses have been worked out depending upon the properties of the tank wall and liquid mass. Tank responses including base shear, overturning moment, tank displacement, and sloshing displacement have been calculated. Results reveal that the system responses are highly influenced by the structural parameters and the earthquake characteristics such as frequency content.

Keywords


[1] Steinbrugge, K.V., Rodrigo, F.A. (1963). “The Chilean earthquakes of May 1960: A structural engineering viewpoint”. Bull. Seismology American, Vol. 53, No. 2, pp. 225–307.

[2] Minowa, C. (1980). “Dynamic analysis for rectangular water tanks”. Recent Adv. Lifeline Earthquake Eng., Japan, pp. 135–42.

[3] Knoy, C.E. (1995). “Performance of elevated tanks during recent California seismic events”. Proceeding of the AWWA Annual Conference & Exhibition.

[4] Haroun, M.A., Ellaithy, M.H. (1985). “Seismically induced fluid forces on elevated tanks”. J. Tech. Top Civil Eng., Vol. 111, No. 1, pp. 1-15.

[5] Reshidat, R.M., Sunna, H. (1986). “Behavior of elevated storage tanks during earthquake”, Proceeding of the

3rd US National Conference on Earthquake Engineering, pp. 2143-54.

[6] Haroun, M.A., Termaz, M.K., (1992). “Effects of soil-structure interaction effects on seismic response of elevated tanks”. Soil Dynamics Earthquake Engineering, Vol. 11, No. 2, PP. 37-86.

[7] Marashi, E.S., Shakib. H. (1997). “Evaluations of dynamic characteristics of elevated water tanks by ambient vibration tests”. Proceedings of the 4th International Conference on Civil Engineering, Tehran, Iran, PP. 367–73.

[8] Dutta, S.C., Jain, S.K., Murty, C.V.R. (2000). “Alternate tank staging configurations with reduced torsional vulnerability”. Soil Dynamics and Earthquake Engineering, Vol. 19, pp. 199–215.

[9] Dutta, S.C., Jain, S.K., Murty, C.V.R. (2000). “Assessing the seismic torsional vulnerability of elevated tanks with RC frame-type Staging”. Soil Dynamics and Earthquake Engineering, Vol. 19, pp. 183–197.

[10] Dutta, S.C., Jain, S.K., Murty, C.V.R. (2001). “Inelastic seismic torsional behavior of elevated tanks”. Journal of Sound and Vibration, Vol. 242, No. 1, pp. 151–167.

[11] Dutta, S., Mandal, A., Dutta, S.C. (2004). “Soil–structure interaction in dynamic behavior of elevated tanks with alternate frame staging configurations”. Journal of Sound and Vibration, Vol. 227, Issues 4-5, pp. 825-853.

[12] Livaoglu, R., Dogangun, A. (2005). “Seismic evaluation of fluid-elevated tank-foundation/soil systems in frequency domain”. Structural Engineering and Mechanics, Vol. 21, pp. 101–119.

[13] Livaoglu, R., Dogangun, A. (2006). “Simplified seismic analysis procedures for elevated tanks considering fluid-structure-soil interaction”. J. Fluids Structure, Vol. 22, No. 3, pp. 421–39.

[14] Livaoglu, R., (2005). “Investigation of the earthquake behavior of elevated tanks considering fluid– structure–soil interactions”. Ph.D. Thesis, Karadeniz Technical University, Trabzon.

[15] Livaoglu, R., Dogangun, A. (2007). “Effect of foundation embedment on seismic behavior of elevated tanks considering fluid–structure-soil interaction”. Soil Dynamics and Earthquake Engineering, Vol. 27, pp. 855– 863.

[16] Westergaard, H.M. (1931). “Water pressures on dams during earthquakes”. Proceedings of the ASCE 57, 1303.

[17] Barton, D.C., Parker, J.V. (1987). “Finite element analysis of the seismic response of anchored and unanchored liquid storage tanks”. Earthquake Engineering and Structural Dynamics, Vol. 15, pp. 299–322.

[18] Dogangun, A., Durmus, A., Ayvaz, Y. (1996). “Finite element analysis of seismic response of rectangular tanks using added mass and Lagrangian approach”. Proceedings of the Second International Conference on Civil Engineering Computer Applications Research and Practice, Bahrain, Vol. I, PP. 371–379.

[19] Zienkiewicz, O.C., Bettes, P. (1978). “Fluid-structure dynamic interaction and wave forces; an introduction to numerical treatment”. International Journal of Numerical Methods in Engineering, Vol. 13, pp.1–16.

[20] Wilson, E.L., Khalvati, M. (1983). “Finite elements for the dynamic analysis of fluid-solid systems”. International Journal of Numerical Methods in Engineering, Vol. 19, pp. 1657–1668.

[21] Olson, L.G., Bathe, K.J. (1983). “A study of displacement-based fluid finite elements for calculating frequencies of fluid and fluid–structure systems”. Nuclear Engineering and Design, Vol. 76, pp.137–151.

[22] Dogangun, A., Durmus, A., Ayvaz, Y. (1996). “Static and dynamic analysis of rectangular tanks by using the Lagrangian fluid finite element”. Computers & Structures, Vol. 59, pp. 547–552.

[23] Dogangun, A., Livaoglu, R. (2004). “Hydrodynamic pressures acting on the walls of rectangular fluid containers”. Structural Engineering and Mechanics, Vol. 17, pp. 203–214.

[24] Donea, J., Gıuliani, S., Halleux, J.P. (1982). “An arbitrary Lagrangian–Eulerian Finite Element method for transient dynamic fluid-structure interaction”. Computer Methods in Applied Mechanics and Engineering, Vol. 33, pp. 689–723.

[25] Housner, G.F. (1963). “Dynamic behavior of water tanks”. Bull. Seismol. Soc. Am., Vol. 53, pp. 381–7.

[26] Bauer, H.F. (1964). “Fluid oscillations in the containers of a space vehicle and their influence upon stability”. NASA TR R 187.

[27] Eurocode-8, (2001). “Silos, tanks and pipelines”, Final PT, European Committee for Standardization, Eurocode-8; Part 4.

[28] Park, R., Kent, D.C., Sampton, R.A. (1972). “Reinforced concrete members with cyclic loading”. Journal of the Structural Division ASCE, Vol. 98, No. 7, pp. 1341–60.

[29] Scott, B.D., Park, R., Priestley, M.J.N. (1982). “Stress-strain behavior of concrete confined by overlapping hoops at low and high strain rates”. ACI Journal Proceedings, Vol. 79, No. 1, pp. 13–27.

[30] Kwak, H.G., Filippou, F.C. (1990). “Finite element analysis of reinforced concrete structures under monotonic loads”. Report No. UCB/SEMM-90/14, Berkeley (CA) University of California.