Experimental study on mechanical properties of high damping rubber bearing model

Abstract

A high damping rubber bearing was designed and manufacturedin order to reduce the seismic response of the bridge structure. The experimental study on its mechanical properties was carried out. The results show: the horizontal equivalent damping ratio is 16.77% when the shear strain is 175%. If the shear strain is larger, the post yield stiffness will be smaller as well as the horizontal equivalent stiffness. However, the equivalent damping ratio and yield force will be larger. If the vertical compressive stress is greater meanwhile the loading frequency is faster, and number of repeated loading is smaller, the equivalent stiffness and the post yield stiffness will be larger as same as the equivalent damping ratio. Destruction didn't occur if the shear strain was no more than allowable shear strain (250%), and the ultimate shear strain was 350%. Compression destruction came when pressure stress was 10MPa. In the case of failure, the bearing was stable, but had large, nonrecoverable vertical and horizontal deformation. The study results can be used as the basis for shaking table test of seismic isolated continuous girder bridge with high damping rubber bearing and the reference for relative seismic isolated bridge design.