Computing Response of Tanks with Two Liquids

A simplified procedure for computing the dynamic response of flexible tanks containing two liquids under a lateral base motion of arbitrary temporal variation is proposed. It requires the input of ground acceleration in the rigid tank solutions to be replaced by the pseudoacceleration function corresponding to the fundamental mode of vibration of the tank‐liquid system. The procedure yields results with good accuracy for tanks with height‐to‐radius ratio ranging from 0.3 to 1.2, a practical range of height‐to‐radius ratio of most tanks. This simple procedure is an extension of the method used for the evaluation of response quantities for flexible tanks with only one liquid. Response quantities that may be computed by the proposed approach include the hydrodynamic pressure, base shear, base moment, and foundation moment. The effect of the soil‐structure interaction on the response quantities can be taken into account. Only the impulsive components of response quantities are considered in the proposed approach, since the convective components can be computed by considering both the tank and its supporting medium to be rigid.