Pressures Exerted on Soil due to Rocking of Liquid Storage Tanks

Abstract

Large pressure exerting on soil due to dynamic response of a liquid storage tank may cause excessive settlement of the supporting soil. Analysis for the dynamic response of such a system should consider the sloshing of liquid in the tank, the associated hydrodynamic pressure, and the coupling effects of liquid with tank and soil foundation. In this study, a simple numerical model is proposed to model the effect of liquid sloshing in tank. The governing equations are derived for the response of a ground‐supported cylindrical tank filled with liquid. It is found that liquid sloshing is dominated by the first mode of motion. Based on this fact, a closed‐form solution is obtained to study the pressures exerted on soil due to harmonic excitation. The dynamic response of the system is examined for various tank sizes, height‐radius ratios, and soil properties. It is found that resonance of such a system occurs due to sloshing of liquid under slow excitation. Under higher frequency excitation, such as that of earthquakes, the effect of liquid also plays an important role in the response of the liquid‐tank‐soil system.