Seismic Performance of Base-Isolated Elevated Liquid Storage Tanks Considering Soil–Structure Interaction

Abstract

Seismic performance of elevated liquid storage tanks, considering soil–structure interaction (SSI), is investigated. The effects of considering SSI on the peak seismic responses, as well as on the seismic fragility of elevated tanks, are presented. A range of soil stiffness, representing very soft soil to hard rock, is considered in the present study. The effectiveness of base isolation technique in enhancing seismic performance of elevated liquid storage tanks is also evaluated. Furthermore, the effects of various parameters—e.g., slenderness ratio of the tank, stiffness of the staging, and natural period of the isolator—on the seismic performance of elevated tanks are studied. Peak responses and seismic fragility of the elevated tanks for two possible configurations of the base isolation system are examined: (1) isolator between staging and foundation, and (2) isolator between the tank and staging. In the present study, it is shown that the seismic fragility of tank structure largely depends on soil stiffness along with staging stiffness. Moreover, regardless of the configuration, the isolation system is observed to be effective in enhancing the seismic performance of the elevated liquid storage tanks.