Paper Title: Reliability of Base-Isolated Liquid Storage Tanks under Horizontal Base Excitation

Numerical Methods for Reliability and Safety Assessment

Sandip Kumar Saha., & Vasant Matsagar

Reliability of base-isolated liquid storage tanks is evaluated under random base excitation in horizontal direction considering uncertainty in the isolator parameters. Generalized polynomial chaos (gPC) expansion technique is used to determine the response statistics, and reliability index is evaluated using first order second moment (FOSM) theory. The probability of failure (p _f) computed from the reliability index, using the FOSM theory, is then compared with the probability of failure (p _f) obtained using Monte Carlo (MC) simulation. It is concluded that the reliability of broad tank, in terms of failure probability, is more than the slender tank. It is observed that base shear predominantly governs the failure of liquid storage tanks; however, failure due to overturning moment is also observed in the slender tank. The effect of uncertainties in the isolator parameters and the base excitation on the failure probability of base-isolated liquid storage tanks is studied. It is observed that the uncertainties in the isolation parameters and the base excitation significantly affect the failure probability of base-isolated liquid storage tank.

Monte Carlo Simulation; Base Shear; Direct Monte Carlo Simulation; Tank Wall; Base Excitation