PERFORMANCE RESEARCH ON LATERAL STIFFNESS OF THE BASE-ISOLATION SHEAR WALL STRUCTURE CONSIDERING VERTICAL DEFORMATION OF ISOLATION BEARING

Different from common seismic structures, due to the vertical deformation of the isolation bearing, certain rigid body rotation will occur in the base-isolated structure under the action of earthquake, thus affecting the lateral stiffness of the superstructure. Moreover,the rigid body rotation is particularly obvious in the shear wall structure. ABAQUS finite element analysis software was used to conduct the nonlinear finite element analysis of the coupled shear wall structure with base isolation. By changing the ratio of tensile and compressive stiffness of the isolation bearings, axial compression ratio and height-width ratio of the walls, thirty finite element models were established to analyze the influence of the rotation of the isolation layer caused by the vertical deformation of the isolation bearing on the seismic performance of the coupled shear wall isolation structure. The results showed that increasing the stiffness ratio and the axial compression ratio, decreasing the height-width ratio could reduce the rotation of the superstructure caused by the vertical deformation of the isolation bearing. Due to the influence of the rotation of the superstructure, the lateral stiffness of the isolated superstructure was obviously lower than seismic structure under the same condition, therefore attention should be paid in engineering design.