Experimental Study On Seismic Performance Of Bundled Lipped Channel-Concrete Composite Shear Wall Considering Bilateral Reinforcement

The steel tube bundle composite shear wall structure system has the advantages of fast construction speed,high degree of industrialization and reasonable layout of building space.It is found that the failure of the steel tube bundle composite shear wall under low-cycle repeated loading is mainly concentrated on both sides of the bottom.Aiming at this failure phenomenon,this paper proposes a way to strengthen the two sides of shear walls.By increasing the wall thickness of the steel pipe on both sides,the buckling resistance of the steel plate at the location of the wall damage is improved,and the mechanical performance of the shear wall is improved.In this paper,the quasi-static loading test,finite element simulation and numerical analysis program are used to study the seismic behavior of steel tube bundle composite shear walls with strengthened sides.The main research contents are as follows:(1)Through the low-cycle repeated load test,the failure modes and mechanical behaviors of the composite shear wall with different reinforcement zone width and steel plate thickness are compared.It is found that the strain level of the fracture position of the steel tube bundle composite shear wall specimen with the reinforcement zone is significantly reduced,the degree of buckling of the steel plate is lighter,and the steel plate has no tear damage.Using the experimental data to draw the hysteretic curve and extract the skeleton curve,further study the seismic performance indicators such as bearing capacity,ductility,stiffness and energy consumption.The indicators show that the bearing capacity of the shear wall increases by 21.1% when the thickness of the steel plates on both sides increases from 3mm to 5mm.Under the condition that the steel content is basically the same,the bearing capacity of the steel-reinforced concrete composite shear wall on both sides is increased 10.2%;the displacement ductility coefficient of the shear wall specimen is between 2.77 and 4.14,and the ductility is better;the equivalent viscous damping coefficient of each specimen is between 0.24 and 0.28,which has good energy dissipation capacity,and the energy consumption area of the test piece with reinforced zone is about 23% larger than that of the ordinary test piece,and the energy consumption capacity is enhanced.The apex displacement caused by the shear deformation of each test piece accounts for about 20% of the total lateral displacement,and the wall deformation is bent and deformed mainly.(2)The finite element numerical simulation method is used to theoretically analyze and compare the effects of different axial compression ratios,shear span ratios,and reinforcement zone widths on the seismic behavior of steel tubular bundle concrete shear walls strengthened on both sides.The results of finite element analysis show that as the axial compression ratio increases,the ultimate bearing capacity of the shear wall increases slightly,the axial compression ratio continues to increase,the peak load decreases significantly and the ductility performance deteriorates;as the shear span ratio decreases,the elastic stiffness and peak load of the shear wall are obviously improved under repeated loading,the shear deformation ratio of the wall increases,the shear bearing capacity is improved,but the ductility performance is deteriorated;in the case of the same steel content,when the strengthening zone is at When the outer wall of the shear wall is the outermost part,the reinforcing effect on the wall is the most obvious,the ultimate bearing capacity is the highest,and the ductility is better.(3)Based on the fiber method and the constitutive relationship of materials,the cross-section analysis program of steel tube bundle composite shear wall is prepared,and the bending-curvature relationship curve of the shear wall under load is drawn.The curve completely reflects the whole process of bending moment and curvature change when the shear wall is loaded.The load-displacement curve is derived by calculating the characteristic point by calculating the section bending moment-curvature skeleton curve calculated by the program and comparing with the test results.The results are in good agreement,and the relevant bearing capacity calculation of the steel-beam composite shear wall can be carried out by using this program.