Analysis On The Influence Of Large Area Opening Of Floor On The Seismic Performance Of Isolated Structures

Atrium building space layout is flexible,and can meet a variety of structural and functional requirements.It has been widely used in shopping malls,science and education,medical care,hotels and other public buildings but also caused the structural problems of large area openings of floor.The large area openings of floor leads to irregular plane of the structure,changes the force transmission path of the structure,enhances the torsional effect of the structure,and makes the response under earthquake more complex.In recent years,the research and engineering application of seismic isolation technology have made remarkable progress,and its application scope has gradually expanded.The seismic isolation technology is applied to complex public buildings with large area openings of floor,which not only achieves good damping effect,but also can meet the protection requirements of cultural relics,precision instruments and other valuables in buildings.At present,the research on the large area openings of floor is mainly focused on the ordinary seismic structures under the action of unidirectional earthquake.the tensile capacity and flexural restraint capacity of the isolation bearing of the isolation structures are weak,which is very bad for the isolation structures with large area openings of floor.Therefore,in this paper,the impact of large openings of floor on the overall seismic performance of isolated structures is studied.the specific works are as follows:(1)The research background and significance of this topic are briefly described,and the research status of irregular isolated structures and large area openings of floor are introduced.(2)Based on an actual seismic isolation project,four models of seismic structure without opening,seismic structure with opening,seismic isolation structure without opening and seismic isolation structure with opening are established,and the influence of large area openings of floor on seismic performance of seismic structures and seismic isolation structures under horizontal bidirectional earthquake is analyzed.(3)In order to analyze the influence of different opening rate and different opening position on the overall seismic performance of the isolated structures,the nonlinear time history analysis of different opening models under the action of unidirectional earthquake,horizontal bidirectional earthquake and near-field earthquake was carried out.The dynamic characteristics,superstructure response,bearing displacement and surface pressure and the strain of surrounding components were analyzed from the aspects of opening rate and opening position.