Research On Seismic Behavior Of U-section Concrete Shear Wall

Special-shaped shear wall is a new type of structure in high-rise building system.The structure absorbs the advantages of traditional shear wall and special-shaped column frame structure,which not only has better bearing capacity but also significantly reduces the construction cost of buildings that need larger space.The structure avoids the phenomenon of protruding columns in practical application,improves the user’s living experience,and is highly praised by architects,developers and users.In the special-shaped shear wall structure system,the U-shaped section concrete shear wall structure developed from the traditional shear wall structure and special-shaped column frame structure has not attracted much attention,especially the scholars have not conducted in-depth research on the response of the structure to the transverse load such as earthquake.In order to analyze the seismic effect of U-shaped section concrete shear wall in detail,this paper,taking the subway operation warehouse under construction in Changchun as the background,appropriately simplifies the details of the project engineering requirements,adjust the proportion of wall body and wall thickness,and designs the super-large section size U-shaped section concrete shear wall structure scheme.The stress mechanism,failure mechanism and seismic performance of the structure are studied in detail.The main work of this paper is as follows:(1)Two scaled U-section shear wall specimens were made and tested by applying low cycle reciprocating load along the centroid in two directions.The force transfer mechanism,failure process and failure mode of U-section shear wall under low cycle reciprocating load in two directions were obtained.(2)Based on the test results of U-section shear wall,the physical and mechanical performance indexes such as bearing capacity,material strain and energy consumption are studied.(3)The finite element analysis of U-section shear walls in two stress directions is carried out by using ABAQUS,and the test conclusions are verified and deepened.By comparing and analyzing the test results and finite element simulation results of Usection concrete shear wall under horizontal loads in different directions,the following conclusions are obtained:(1)U-section concrete shear wall is a uniaxial symmetric section,and its integrity and seismic performance are better when it is stressed parallel to the wall limb than when it is stressed parallel to the web.(2)U-section concrete shear wall has greater bearing capacity limit for web side load.After reaching the peak load,its bearing residual capacity is greater than that of wall limb side,and the energy dissipation characteristics are better than that of wall limb side as a whole.(3)As the bottom layer of the actual project,the U-shaped section shear wall belongs to the area of bottom reinforcement.Considering the large bending moment at the bottom end of the wall limb,the bottom end of the wall limb should be designed and constructed according to the key parts in the actual project.(4)Although there is a certain deviation between the finite element analysis results and the actual test data,there is little difference in the absolute energy consumption characteristics between the two,indicating that the finite element model can better reflect the actual situation.