掉层钢筋混凝土框架结构上接地隔震性能分析OA

Due to the highly uneven distribution of lateral stiffness between the upper grounding side and the split-foundation side of a split-foundation reinforced concrete frame structure,the"half-layer yielding"phenomenon occurs in its upper ground plane,which undermines the overall seismic perfor-mance of the structure.Based on the design concept of uniform lateral stiffness in the upper ground plane,an upper-ground isolation structural system was established by installing isolation bearings at the base of the upper ground columns,with horizontal stiffness close to the average lateral stiffness of the split-foundation side columns.The distribution of column shear forces,maximum interstory dis-placement angles,and plastic hinges in the upper ground plane under earthquake was analyzed,and the influence of isolation bearing specifications on the seismic performance was investigated.The re-sults indicated that using isolation bearings with horizontal stiffness close to the average lateral stiff-ness of the split-foundation side columns could significantly improve the uniformity of column shear force distribution in the upper ground plane,reduce the maximum interstory displacement angle of this plane,and prevent severe local damage to the upper ground columns,thereby lowering the risk of lo-cal structural collapse.In design,the damage level of the structure under rare earthquakes can be con-trolled by adjusting the ratio of the stiffness of the selected isolation bearings to the average lateral stiff-ness of the split-foundation side columns,thereby enhancing the overall seismic performance of the structure.