Study on Parameter Combination of Quasi-Isolation System of Beam Bridge with Laminated Rubber Bearing
In order to overcome the defects of beam bridge with laminated rubber bearing,such as insufficient limit capacity and self-reset capacity,a method of combining X-shaped elastic-plastic steel retainer,viscous damper and laminated rubber bearing in longitudinal and transverse bridge directions is proposed to form quasi-isolation system of laminated rubber bearing beam bridge to improve the seismic performance of the bridge.A refined finite element model of a four-span continuous beam bridge is established by using OpenSees.The mechanical performance parameters of X-shaped elastic-plastic steel retainer and viscous damper are analyzed by the seismic response of main beam displacement,column internal force,bearing shear force and displacement.The results show that the combination of X-shaped elastic-plastic steel retainer and laminated rubber bearing can effectively control the displacement of the beam under earthquake,and basically eliminate the residual displacement after earthquake.In addition,under the condition of reasonable selection of mechanical properties of retainer,the shear force and displacement of the bearing can be effectively reduced,and the inertia force transmitted to the substructure of the bridge can be reduced to play a protective role.The combination of longitudinal bridge viscous damper and laminated rubber bearing can reduce the maximum displacement and residual displacement of beam end to a certain extent by adopting reasonable parameter selection,and greatly reduce the internal force of column,so as to ensure that the substructure of bridge is protected from serious damage.The conclusion is that the quasi-isolation system of laminated rubber bearing beam bridge can effectively improve the seismic performance of the bridge and solve the problem of excessive displacement of beam under strong earthquake.