| Statistical data of large earthquakes at home and abroad show that super intensity usually occurs when a large earthquake occurs,and the ductility of the building structure decreases sharply because of bearing too high axial compression ratio,resulting in serious damage or even collapse of the building designed according to the local fortification intensity.Shear wall is the main anti lateral force component of the high-rise building structure.It takes the bending failure with good ductility as the design goal,but it presents the brittle failure characteristic under the high axial compression ratio,which is disadvantageous to the anti-seismic of the structural system.Some researchers improve the seismic performance of shear wall by adaptive joint,which is the same as the ordinary shear wall in small and medium earthquakes and can automatically joint to form several split walls with a large shear span ratio in large earthquakes to continue to work,making the ultimate failure ductile.However,the previous research on the "adaptive split shear wall" is aimed at ordinary concrete,which has the low bearing capacity and energy consumption,and it is easy to occur shear slip failure due to the reduction of wall stiffness after the split.On the other hand,the popularization of green environmental protection and sustainable policy has made the use of machine-made sand more and more mature.Based on this,this paper designs a new type of composite shear wall,which is composed of steel tube and high-strength mechanism sand concrete,and studies its seismic performance under the super-high axial compression ratio.In this paper,four new composite shear wall specimens are designed.Using the orthogonal design criterion of "three factors an d two levels",the influence of axial compression ratio,steel ratio and volume stirrup ratio on the seismic performance of the members in this paper is studied,including bearing capacity analysis,deformation analysis,stiffness analysis,energy consumption analysis,etc.,and the self-split mode and limit state of the specimens are obtained through the test The main contents are as follows:(1)The low cycle cyclic loading tests under a super-high axial compression ratio were carried out on four new types of self-slotted composite shear walls.The deformation in the process of cracking,yielding,peak value,limit,and failure of the new type of self-slotted composite shear walls were investigated.The development,failure form,failure process and mode of the cracks in the loading process were described in detail.At the same time,the horizontal and vertical deformation between the vertical joints and the material were combine,the mechanism of self-splitting is obtained by strain.(2)The yield state and limit state of the members in this paper are defined.The loaddisplacement hysteretic curve and skeleton curve of the members with different parameters are studied.The bearing capacity and deformation characteristic points of each member are orthogonal analyzed.The influence factors and the degree of the two parameters in this paper are studied.(3)The seismic performance indexes of the specimens with different parameters are analyzed,including the degradation of bearing capacity,stiffness,deformation and energy consumption,and the section strain distribution of the members is obtained.Finally,the orthogonal analysis of the seismic performance indexes is carried out,and the optimal parameter combination based on the seismic performance indexes is obtained.(4)The formula of horizontal bearing capacity of composite restrained high-strength concrete-filled steel tubular shear wall proposed by the research group is verified and compared with the standard formula.Finally,based on the test results,the design suggestions for the application of such components in practical projects are put forward. |
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