Optimizing the seismic response of base-isolated liquid storage tanks using swarm intelligence algorithms

Abstract

Large-scale liquid storage tanks are used worldwide for storing water, chemicals and fuels, such as liquefied natural gas (LNG) and oil. Any major damage due to man-made or natural hazards, such as earthquakes, to these critical infrastructures would cause serious socio-economical losses and devastating environmental consequences. Moreover, they should remain functional even after a severe earthquake to support restoration actions, thus, their robust and optimal seismic design is deemed necessary. For this reason, base isolation is generally considered as a highly efficient technique for their seismic protection. Elastomeric bearings, such as lead-rubber bearings (LRB), high damping rubber bearings (HDRB) and friction bearings: single friction pendulum bearings (SFPB), double friction pendulum bearings (DFPB) and triple friction pendulum bearings (TFPB) have been used. In this work, the focus is given on the sizing optimization of the main parameters of SFPB and TFPB isolators. For this reason, efficient swarm intelligence optimization algorithms are used to derive optimal friction coefficient and radius of curvature values that enhance the dynamic performance of a base-isolated liquid storage tank. The main objective of the proposed formulation is to minimize the accelerations transmitted to the superstructure, while constraints related to damping and vibration period of the system are imposed.