Dynamic Properties of Lead Rubber Bearings and its Seismic Isolation Applications in High-Speed Railway Bridge

Lead rubber bearing (LRB) is a new type of earthquake-resistance rubber bearings, formed by inserting lead-core into ordinary laminated rubber bearing, vertical supporting, horizontal displacement and hysteretic damping are hung in single unit together. For lead-core can dissipate seismic energy and increase stiffness under load simultaneously, and most of the requirements of the Seismic isolation system can be satisfied, the material-device has been found widespread application prospect in bridge engineering. Hysteretic behaviors, ductility, and energy dissipation of LRB are mainly determined by some dynamical parameters such as characteristic intensity of LRB, post-yield, pre-yield stiffness and so on. Equivalent linear model of hysteretic characteristics, computational method and the varying range of dynamic parameters of LRB are presented. Dynamic responses of high-speed railway bridge fabricated LRB are calculated, and calculation results are compared with those fabricated common bearings, factors which influence seismic isolation are analyzed.