ISOLATED EFFECTION OF THE XIAZHANG CROSS-SEA ISOLATED BRIDGE

In this study, the real-time hybrid loading test system based on the velocity-based loading concept is developed. The test system utilizes the concepts of the real-time hybrid loading test method and the substructure technique to combine the loading process of rubber-bearing specimens and numerical modeling of bridge columns and girders. Newly developed components of the loading test system include: an axial loading device especially devised for the fast loading of rubber bearings, and a real-time test control algorithm using the velocity-based loading concept, implemented to a PC-DSP system framework for the actuator control signal processing. A series of real–time hybrid loading tests on natural rubber (NR), high-damping rubber (HDR), and super-high-damping rubber (HDR-s) bearings are conducted using the test system. The objective of this study is to pursue accurate prediction of the dynamic response and base isolation effects of rubber bearings under realistic earthquake conditions. Specifially, the base isolation effects of HDR-s bearing are discussed. Based on the test results, it is clarified that the HDR-s bearing is more effective than the HDR and NR bearings.