BASIC STUDY ON CHARACTERISTICS OF LEAD RUBBER BEARINGS UNDER HORIZONTAL BI-DIRECTIONAL DEFORMATION

The purpose of this paper is to clarify the hysteretic behaviors of seismic isolation bearings under horizontal bi-directional deformation. The force vector of seismic isolation bearings with damping consists of elastic component and damping component. Elastic component and damping component are caused in a different direction by horizontal bi-directional deformation. We apply an analytical model for seismic isolation bearings which expresses the constantly changing direction of the two force components to lead rubber bearing. The validity of the model is confirmed by comparing analytical results calculated by the model with experimental results of horizontal bi-directional loading tests of lead rubber bearing. Based on the analytical results calculated by the model, investigation of hysteretic absorbed energy of lead rubber bearings under horizontal bi-directional deformation is conducted.