Seismic Performance Study On Unbonded Post-tensioned Self-centering Concreteshear Wall With Full Opening Of Bottom With Concealed Steel Plate Brace

Reinforced concrete shear wall structure has the advantages of good spatial integrity and high seismic performance,and has been widely using in high-rise buildings in China.However,after the action of earthquake,the damage and residual deformation oh the traditional shear wall structure are serious,and difficult to strengthen and repair it.In this paper,two kinds of bottom fully opening unbonded post-tensioned self-centering shear wall structures with concealed steel plate brace are proposed,that is,self-centering shear wall(ZFW-1)with shear steel rod and self-centering shear wall(ZFW-2)with hinged member,both shear walls are composed of the self-reset shear wall,X-shaped concealed steel plate brace,energy-consuming steel bar,unbonded post-tensioned prestressed steel tendons and so on.In this paper,the experimental study and finite element analysis are combined to systematically study and analyze the seismic resistance of th e bottom fully open seam self-centering shear wall with concealed steel plate brace,the main research contents are as follows:(1)Through quasi-static cyclic load test,the seismic properties of the two kinds of self-centering shear wall with full opening of bottom with concealed steel plate brace are analyze,including bearing capacity,hysteresis curve,skeleton curve,stiffness degradation,energy dissipation capacity and residual deformation.The test results show that the cracks and damage of the two sh ear wall specimens are mainly concentrated in the corner of the wall,no cracks appeared in the middle of the wall,the crack range of the specimen ZFW-2 is slightly larger than that of the specimen ZFW-1,and the obvious opening and closing phenomena can be observed at the open seam during the test;The lateral load carrying capacity and energy dissipation ability of the specimen ZFW-1 are better than that of the specimen ZFW-2,and the hysteresis curve of the two specimens is more full than that of the tr aditional self-centering shear wall,and the X-shaped concealed steel plate brace increases the energy consumption of the wall body;The residual deformation of the two specimens has little difference,the maximum residual displacement angle is 0.45% and 0.43% respectively,which indicates that the two specimens have good self-centering characteristics.(2)By using ABAQUS to simulate the two specimens,the finite element model have a test under monotone horizontal load,and the curve of analysis and the test results are compared and analyzed,and the results are in good agreement,which shows that the finite element model and setting parameters established in this paper are reasonable.(3)Account of the reliability of simulative model,some parameters such as axial compression ratio,thickness of concealed steel plate brace,yield strength of concealed steel plate brace,area of unbonded prestressed steel tendons and initial prestress are modified and simulated,analyzing the influence of parameter changing on seismic performance of specimens.The simulation results show that increasing the axial pressure ratio and the initial prestressed value of the steel tendons have a great influence on the bearing capacity and stiffness of the specimen;Increasing the thickness of concealed steel plate brace can provide the bearing capacity and energy consumption of the specimen;Excessive yield strength of steel plate brace has less effect on seismic performance of specimens;Changing the section size of prestressed steeltendons without maintaining a unilateral total prestress value has little effect on the structure.