Seismic Performance Analysis Of Prefabricated RC Double-Limb Shear Wall Based On Cast-Inplace Connection Of Edge Members

In recent years,with the advancement of building industrialization,prefabricated building has been rapidly developed and applied.The connection technology of prefabricated concrete structural members is the key to seismic performance of the structure and has always been the focus of research in the industry.At present,the concrete structural members are connected in various ways,but the wet connection is still the main way.The wet connection way is widely used because of its ductility,seismic performance,bearing capacity,integrity,stiffness and strength.Among them,the vertical connection of steel bars mostly adopts sleeve grouting connection.Because of the frequent quality accidents and high cost of steel bars’ sleeve grouting connection in recent years,it has been restricting the popularization of prefabricated buildings.In order to solve these problems,a new type of prefabricated concrete shear wall is proposed in this paper.The lapped rebars area is set at the bottom of the wall limbs,and the stirrups are densely arranged in this area.Then concrete is poured to form a whole shear wall.As the connection between reinforcement and concrete adopts the traditional cast-in-place concrete connection mode,the connection quality is reliable and the construction cost is low.It has good application prospect and market promotion value.By searching relevant literature and using ABAQUS finite element software,20 specimens with different parameters were established respectively,and the data of each specimen were compared to study their seismic performance under pseudo-static test.Specific research contents are as follows:(1)Verify the accuracy and reliability of ABAQUS finite element software for simulation analysis of pseudo-static test.According to the design parameters of the specimen in reference 57,the finite element software ABAQUS was used for modeling and analysis,and the test data in reference 57 were compared to verify the reliability of the finite element analysis results.(2)ABAQUS software was used to model the edge member cast-in-place joint prefabricated RC double-limb shear wall SW-2 and the fully cast-in-place RC doublelimb shear wall SW-1.The simulation data were analyzed and compared,and the seismic performance of the two specimens was compared according to Specification for seismic test of buildings(JGJ/T 101-2015).The results show that the initial stiffness of SW-1 is greater than SW-2.The hysteresis curves are fusiform with good energy dissipation capacity and similar energy dissipation capacity.The failure forms of the two specimens are similar,and the main failure locations of concrete occur at the intersection of the top of the wall limb and the connecting beam and at the bottom of the wall limb.The trend of skeleton curve is similar and the bearing capacity is not different.The ductility of SW-1 is large,and the ductility ratio of both specimens is greater than 3,indicating good ductility.It can be seen that in the pseudo-static test,specimen SW-2 can exert the same mechanical properties as specimen SW-1,and has better seismic performance.(3)Based on the numerical simulation of SW-2 specimen,the axial compression ratio,concrete strength,the distance between stirrups in the wall limb,the inclination Angle of the contact surface between the old and new concrete at the bottom of the wall limb and the strength parameters of the longitudinal reinforcement in the wall limb were changed,and the influence of each parameter on the seismic performance of SW-2 specimen was analyzed,which laid the foundation for the practical engineering application.The simulation data show that the failure morphology of all specimens is affected by the change of parameters in different degrees.The ductility ratio is greater than 3,and the ductility performance is good.The bearing capacity and stiffness of specimens increase with the increase of concrete strength grade and axial compression ratio.The change of stirrup spacing in the wall limb has a great influence on the damage of concrete,because the stirrup ratio increases with the decrease of stirrup spacing,improving the binding force of stirrup on the internal concrete and longitudinal reinforcement,and slowing down the damage of concrete.By changing the inclined Angle of the contact surface between the old and the new concrete at the bottom of the wall limb,it is found that the failure position of the concrete at the bottom of the wall limb mainly occurs in the part of the post-cast concrete,so the strength level of the post-cast concrete can be appropriately improved to reduce the damage degree.The change of longitudinal bar strength has little effect on the seismic performance of the specimen.The inter-storey displacement Angle of each specimen meets the limit value 1/120 of the elastic-plastic displacement Angle limit value of shear wall structure in Code for Design of Concrete Structures(GB50011-2010).