Seismic Behavior Research Of Frame-Supported Shear Wall Structure Of High-Rise Building

With the acceleration of urbanization in China,problems such as lack of land resources and traffic congestion come along,which brings great pressure to the city.At present,the utilization of subway superstructure can alleviate the shortage of land in big cities in China,provide new opportunities for urban construction,and become the focus of research.Due to the need for large space in the subway passage in the lower part of the upper cover structure,the vertical members covered with a small property space are not allowed to extend to the bottom of the structure.In order to realize this kind of architectural function,a new structural form—frame supported shear wall structure system without landing shear wall(also known as full frame-supported shear wall structure)has been born.At present,there is still a lack of research on the applicable conditions and collapse mechanism of the structural system.In this paper,based on the conversion project of full frame support of a subway roof in Guangzhou,a series of full frame supported shear wall structures are designed,and the seismic performance and collapse mechanism of the structural system are analyzed by the seismic performance evaluation method based on member deformation.the purpose of this paper is to provide a theoretical basis for this type of structural design in the future.The specific research contents of this paper are as follows:(1)Combined with the idea of performance-based seismic design,a seismic performance evaluation method based on member deformation considering structural collapse mechanism is proposed.(2)Based on the current code,13 structural models are designed.Nine models of fullframe-supported shear wall structure system with different fortification intensity and building height are group A.based on the first typical full-frame-supported shear wall structure in group A,four full-frame shear wall models with different limit values of axial compression ratio of frame struts are designed as group B.The elastic design of the model structure is carried out by using mode decomposition response spectrum method and time history analysis method.The reasonable seismic wave is selected for each model,and the elastic-plastic time-history analysis of the structure under rare earthquake is carried out by using Perform-3D.Then verifing the effectiveness of the elastic-plastic analysis model and results.(3)From the elastic-plastic calculation results of group A,this paper expounds the distribution law of the inter-story displacement angle,shear force,overturning moment and the performance state of each member under the action of large earthquake.To judge whether it meets the fortification requirements of "unbreakable by small earthquakes,not collapsed by large earthquakes" and the seismic design idea of "strong conversion to weak upper part".The applicable scope of the structure in fortification intensity and building height is analyzed.(4)From the elastoplastic time history analysis of group A model under rare earthquake,the change of the overall failure state and the change process of the normal section deformation and oblique section bearing capacity of each member are explained.Through the failure form and failure sequence of the members,the performance change and failure sequence of the frame-supported frame structure and the upper shear wall structure of the transfer floor are revealed.In this paper,the collapse performance state of full frame-supported shear wall is defined,the relationship between structural collapse state and member performance state is established,the distribution of structural weak layer and its reason are revealed,and the collapse mechanism of full frame-supported shear wall structure is explained.(5)Through the elastoplastic time-history analysis of B model under rare earthquake,the relationship between the limit of axial compression ratio of frame struts and the collapse mechanism of full frame-supported shear wall model is revealed.The reasonable limit values of axial compression ratio,yield strength coefficient ratio and lateral stiffness ratio of full frame-supported shear wall structure under 7-degree fortification intensity are put forward to ensure the reasonable collapse mechanism of the structure.