Applicability Study on High Damping Rubber Bearing for Highway Bridge in Soft Soil

In this paper, applicability study on high damping rubber bearing for highway bridges in soft soil conditions is carried out by using nonlinear time history analysis. 5-span continuous girder bridges with same superstructure but different substructure stiffness are taken as case bridges. Artificial ground motions with long characteristic period were fitted for the analysis. Seismic response comparison of case bridges with high damping rubber bearing and laminated rubber bearing show that: high damping rubber bearing does not prolong the natural period of the bridge, so compared with laminated rubber bearing, it acts more like a damper than isolator during strong earthquake. And the substructure stiffness of the bridge has great influence on the damping effect of high damping rubber bearing. When the substructure of the bridge is too flexible, the high damping rubber bearing has little damping effect. But, when the substructure of the bridge is rigid, the high damping rubber bearing still have great damping effect even in soft soil.