Shaking table and pseudodynamic tests for the evaluation of the seismic performance of base-isolated structures

This paper describes a series of shaking table and pseudodynamic tests for the evaluation of seismic performance of base-isolated structures subjected to various seismic earthquake inputs. The main objectives of this study are: (1) evaluation of the effectiveness of base isolation systems for low-rise structures against severe seismic loads through shaking table tests; (2) verification of the substructuring pseudodynamic test method for base-isolated structures in comparison with the shaking table test results; and (3) development of an analytical method for predicting earthquake responses of base isolation systems. In the shaking table test, a quarter-scale three-storey structure base-isolated by laminated rubber bearings is tested. In the pseudodynamic test, only the laminated rubber bearings are tested using the substructuring technique, whereas the concurrent seismic responses of the superstructure are computed using on-line numerical integration. Comparison with the shaking table test results indicates that the substructuring pseudodynamic test method is very effective for determining the dynamic responses of the base-isolated structure. It has also been found that the analytical method with a bi-linear hysteretic model for the base isolator can reasonably predict the earthquake responses of base isolation systems.