Wind Effects on Base‐Isolated Structures

Abstract

The sensitivity of base‐isolated structures to wind loadings is studied. The wind velocity is decomposed into mean and random fluctuating parts. A stationary random model for the fluctuating part of wind velocity is considered and the method of equivalent linearization is used for response analysis. Displacement‐response statistics, including autocorrelation, power spectrum, and variance of a rigid structure, are evaluated for the laminated rubber bearing (LRB), the high damping rubber bearing, and the resilient‐friction base isolator (R‐FBI) base‐isolation systems. The results show that base‐isolated structures are not sensitive to wind loading during common storms. However, for severe hurricanes, displacements on the order of a few centimeters may be expected. The presence of a frictional element in the base‐isolation system significantly reduces its sensitivity to strong wind loadings. High damping in the base‐isolation system decreases the displacement due to the fluctuating part of wind excitation.