Study On Seismic Damage And Re-Centering Performance Of The Self-Centering RC Shear Wall Structure

In order to reduce the damage and residual deformation of reinforced concrete（RC）frame-shear wall structure after earthquake,this paper proposes to apply the self-centering RC shear wall with disc spring devices to the frame-shear wall structure.The disc spring devices are installed at the wall toes to provide the restoring force for the wall and protect the concrete at the bottom corner from damage.The hysteretic behavior and damage evolution process of self-centering RC shear wall are studied through the low cyclic loading tests.A restoring force model that can accurately describe the hysteretic behavior of the disc spring devices is proposed and developed,and the effects of different parameters of the disc spring devices on the performance of the self-centering RC shear wall are studied through numerical simulation.The nonlinear dynamic time history analysis is conducted to study the damage characteristics and self-centering performance of the RC frame-self-centering shear wall structure under frequent,fortification and rare earthquakes.The main contents and achievements are summarized as follows:（1）The configuration and working principle of the self-centering RC shear wall are introduced.A self-centering RC shear wall specimen and a traditional RC shear wall specimen were designed and a series of low cyclic loading tests were conducted to compare and analyze the hysteretic behavior,energy dissipation capacity,horizontal stiffness degradation,residual displacement and damage evolution process.The results indicate that the skeleton curve of the self-centering RC shear wall still does not decrease and the bearing capacity is slightly reduced compared to the traditional RC shear wall when the loading drift ratio reaches 3%.However,the maximum loading drift ratio of the self-centering RC shear wall is increased by 44.4%,and the final cumulative energy dissipation is increased by 61.9%,indicating that the self-centering RC shear wall has better deformation ability and energy dissipation capacity.The residual displacement of the self-centering RC shear wall is smaller than that of the traditional RC shear wall at the same loading displacement,and the maximum residual drift ratio of the self-centering RC shear wall is reduced by about 65.8%,indicating that the self-centering RC shear wall specimen has a good self-centering performance.Furthermore,the self-centering RC shear wall specimen has relatively few cracks,and the cracks develop relatively slowly.The longitudinal rebar strains of the constraint boundary column and the horizontal distributed rebar strains are all less than those of the traditional RC shear wall,which indicates that the self-centering RC shear wall specimen has less damage.（2）The working principle and mechanical behavior of disc spring device are analyzed to accurately simulate the mechanical performance of disc spring device and the self-centering RC shear wall.Furthermore,the restoring force model of disc spring device is proposed and developed.The accuracy of the restoring force model is verified through experiments.The hysteretic performance of the self-centering RC shear wall with disc spring device is numerically simulated and compared with the experimental results due to cyclic reversed loading.Results indicate that the numerical model using a restoring force model of disc spring device can effectively simulate the hysteretic behavior,self-centering performance and energy dissipation capability of the self-centering RC shear wall.The error of bearing capacity and hysteretic energy dissipation is less than 10% in most loading levels,except for individual loading levels in the initial stage of loading.The bearing capacity of the self-centering RC shear wall increases with the increase of the pre-pressed force of disc springs,the additional friction force and the stiffness of disc spring device.The energy dissipation capacity increases with the increase of the additional friction force.The residual displacement increases with the increase of additional friction and decreases with the increase of the pre-pressed force and the stiffness of disc spring device.（3）A prototype structure and two RC frame-self-centering shear wall structures with different locations and numbers of disc spring devices are designed and modeled.The dynamic responses and damage of the three structures under frequent,fortification and rare earthquakes are compared and analyzed through numerical simulation.The results show that the RC frame-self-centering shear wall structures have smaller interstory drift ratio,the displacement response,and the floor acceleration response under fortification and rare earthquakes than the prototype structure.The disc spring devices have stable energy dissipation capacity and self-centering performance under rare earthquakes,which reduces the maximum residual interstory drift ratio of the two self-centering structures by 47.2% and 36.7% respectively compared with the prototype structure.The damage degree and area of the walls of the RC frame-self-centering shear wall structures after earthquake are significantly reduced compared to the prototype structure.The increase of floors with disc spring devices can more effectively control the displacement response,floor acceleration response and wall damage of the structure.