Abstract
For the purpose of predicting the large displacement response of isolated buildings, an analytical model for elastomeric seismic isolation bearings is proposed. The model consists of shear and axial springs at mid-height, and a series of axial springs at the top and bottom. The properties of elastomeric bearings vary with the imposed axial stress. At large shear deformations, elastomeric bearings exhibit a hardening behavior under low axial stress and buckling under high axial stress. The properties exhibited depend on the interaction between the horizontal and vertical forces. The proposed model includes the interaction between horizontal and vertical forces, non-linear hysteresis, and dependence on axial stress. To verify the validity of the model, analyses are performed for actual static loading tests of lead-rubber bearings. The results of the analyses show very good agreement with the experimental results.
