Seismic response of concrete rectangular tanks for liquid containing structures

Abstract

In this paper, a procedure for computing hydrodynamic pressures in rectangular tanks is proposed. The procedure, which is referred to as the sequential method, considers the effect of the flexibility of the tank wall in determining the hydrodynamic pressures. In this study, only the impulsive response of the tank is considered. Based on a two-dimensional model of the tank wall, dynamic time-history analysis is carried out to study the effect of wall flexibility on the response. In the analysis, both a tall tank and a shallow tank are considered. The results of analysis are compared with those obtained based on current design practice codes and standards. The well-known Housner's model, which assumes that the mass of liquid is lumped on the wall based on rigid wall boundary condition in the calculation of hydrodynamic pressure, is widely used in practice. A comparison shows that in most cases, the lumped mass approach overestimates the base shear. The effect of wall flexibility on wall displacements, base shears, and moments are also discussed.Key words: reinforced concrete, liquid containing, rectangular tank, seismic, dynamic analysis, tank flexibility.