By J. Z. Chen - Graduate Student, Department of Civil Engineering, Ryerson University, Toronto, Ontario, Canada.
M. R. Kianoush - Professor, Department of Civil Engineering, Ryerson University, Toronto, Ontario, Canada.

In most of the current design codes and standards for concrete liquid storage tanks, the hydrodynamic pressures are determined assuming that the tank walls are rigid. The Housner’s model, which assumes that the mass of liquid is lumped on the wall based on rigid wall boundary condition in the calculation hydrodynamic pressure, is widely used in practice. Previous research has indicated that the flexibility of wall can affect the distribution and magnitude of hydrodynamic pressures. In this paper, the effect of wall flexibility on hydrodynamic pressures in concrete rectangular tanks is studied using an approach referred to as the sequential method. The procedure on how to establish the impulsive hydrodynamic pressures using the sequential method based on a two-dimensional analysis is described. A comparison shows that the lumped mass approach overestimates the base shear and wall displacements.