Seismic Performance Of Self-centering Shear Walls With Horizontal Bottom Slit Under Rear Earthquake

Self-centering structure has a less structural damage and obviously reduces residual displacement under the action of earthquake,which saves time and cost in post-earthquake repair.Self-centering shear walls structure is a hotspot in today's study of the self-centering structure.At present,the research on self-centering shear walls structure is mainly concentrated on the single limb shear walls component.As for the whole structure,the research is more mature on frame-self-centering shear walls.But how to realize structural reset only with shear wall is still staying in the component test and software analysis stage.The research is inadequate.Therefore,it is necessary to develop studies on the self-centering capacity and the seismic performance of the self-centering shear walls.This paper will focus on studying the seismic performance of self-centering shear walls with horizontal bottom slit under rare earthquake.The comparison between self-centering shear walls with horizontal bottom slit and common shear walls will be made first by means of PERFORM-3D,a finite element analysis software.Then the parameter analysis centering on the size and position of horizontal slits,the level and position of prestress and dampers will be carried out.Finally the influence brought by parameter variation on the self-centering capacity of the self-centering shear walls and seismic performance will also be studied.The main conclusions are as follows:(1)Self-centering shear walls structure has a good self-centering capacity,which is mainly embodied in the smaller residual displacement after an earthquake.(2)The displacement response of self-centering shear walls structure is greater than common shear walls and the energy dissipation capacity of that is less than ordinary one in post-earthquake.However,the energy dissipation of beam members and damping in the structure is increased,causing the total amount of dissipated energy of the whole structure is higher than ordinary shear walls.(3)The self-centering shear walls structure using beam members suffers more in an earthquake than ordinary one and has an increased yield probability of bending failure,and also has slightly improved yield probability of shear walls in the bottom floor as well as decreased yield strength of the structure,at the same time possesses a higher curvature ductility factor than that of ordinary one.The probability of shear and cracking of the lowest several slab levels in the buildings in self-centering shear walls is improved compared with that of common shear wall structure.But no shear yielding is observed in the earthquake,that is to say,the main structure is still mainly based on bending failure.(4)When the length of the horizontal slits is 1/5~1/4 of that of the wall,the self-centering capacity of self-centering shear walls structure is best.It has little influence on structural period,displacement response and performance of automatic resilience when the layer of horizontal slits exceeds three.(5)The initial prestress of prestressing tendon in self-centering shear walls structure has little impact on the self-centering capacity of the structure.Increasing the length of prestressing tendon or enhancing initial prestress will increase structural energy dissipation.And both of them could enhance structural energy dissipation capacity.If the prestressing tendon is arranged more than 10 storey in tall self-centering shear walls structure,its influence to the self-centering capacity would be reduced.(6)Adding viscous damper in tall self-centering shear walls structure can strengthen its self-centering capacity.The self-centering capacity of the damper arrangement is the best in larger harmful drift in the structure.Increase the number of viscous damper and raise viscous damping coefficient can also strengthen structural self-centering capacity.The layout of the damper will not affect the total energy dissipation of the structure and on the nonlinear energy consumption of self-centering wall,but will greatly decrease the nonlinear energy consumption of beam members and mitigate its damage.