Research On Seismic Performance Of Assembled Integral Single-Side Composite Shear Walls With Horizontal Joints

The development direction of the transition from the construction industry to the new architectural structure has led to a rapid development of the prefabricated building structure.The prefabricated superimposed floor structure is a very widely used structural form.It has the advantages of shortening construction period,good integrity,reducing pollution to the environment,and high degree of industrialization.The single-sided superimposed shear wall structure is a special superimposed form in the superimposed shear wall structure,but it is more convenient to use a new type of superimposed form.It is particularly necessary to study its seismic performance.In this paper,a fully cast-in-place reinforced concrete shear wall and a singlefaced superposed reinforced concrete shear wall full-scale test piece with horizontal seams are designed and manufactured,and subjected to pseudo-static seismic test research.At the same time,the finite element software ABAQUS two kinds of shear walls are modeled and analyzed.The specific research contents are as follows:(1)A pseudo-static test with low-cycle horizontal reciprocating loading is performed on the in-situ shear wall and the single-sided shear wall under low axial compression ratio to observe the test phenomena,crack development,bearing capacity change,and various measurements.Point displacement and reinforcement strain.Both the cast-in-situ shear wall and the single-sided shear wall are subject to bending and shear failure;the ultimate bearing capacity of the in-situ shear wall and the single-side shear wall is greater than that calculated according to the “Specifications for Design of Concrete Structures” GB50010-2010.The theoretical ultimate bearing capacity meets the requirements of the code;the number of cracks on single-sided superimposed shear walls is less than that on cast-in-place shear walls;there is no obvious slippage between cast-in-place concrete and prefabricated wallboards,and the overlapped surfaces are well connected.(2)Analyze the data of the displacement and bearing capacity of each measuring point obtained from the test,and obtain the hysteresis curve,skeleton curve and stiffness degradation curve of the in-situ shear wall and the single-sided superimposed shear wall.The results are basically the same.The peak loads,ultimate loads,and displacements of the characteristic points of the single-sided superimposed shear wall are slightly smaller than those of the in-situ shear wall.The early-stage stiffness is greater than the in-situ shear wall,and the stiffness is degraded faster,and the post-rigidity is basically the same.There is a slight relative slip between the outer blade and the inner blade,which is negligible compared to the overall displacement of the wall.(3)The ductility coefficient and energy dissipation coefficient of in-situ shear wall and single-side shear wall are obtained by calculation.The ductile performance and energy dissipation performance of single-side shear wall are stronger than that of in-situ shear wall.It can meet the seismic energy dissipation capacity and displacement ductility required in the project;the lateral vertical connection steel strain is relatively large,and the strain of the steel bars in the cast-in-place layer and the prefabricated panel has little difference.(4)After modeling and analysis of two shear walls using ABAQUS finite element software,concrete and steel stress-strain cloud images,hysteresis curves,skeleton curves,and steel strains of cast-in-situ shear walls and single-sided shear walls are obtained.: The vertical beams connected to the ground beams are subjected to the greatest stress and strain.The concrete receives the largest compressive stress at the corners and the concrete has the largest strain at the joints.It is the most vulnerable to damage.All of them are consistent with the test phenomenon;hysteresis curves and skeletons.The curve is basically consistent with the test results,and the model is reasonable and effective.(5)The parameters of the cast-in-situ concrete strength and axial compression ratio are changed: The change of the strength of the cast-in-place concrete layer has basically no effect on the failure mode of the wall;the greater the strength of the castin-place concrete,the higher the bearing capacity of the wall.At the same time the residual deformation will also be slightly reduced;the higher the strength of the castin-place concrete,the smaller the strain of the steel bar.The larger the axial compression ratio,the main strain area of concrete and steel bars rises up to the middle and lower part of the wall.The single-sided superimposed shear wall joins the key position from patchwork seam to the middle and lower part of the wall;the outer blade concrete has significant compressive strain.Increase;the greater the axial compression ratio,the greater the peak load of the component and the reduction of residual deformation;the vertical reinforcement of the lower part of the steel bar and the bottom bar have very small strains,and the middle and lower steel bars and the Haven joints are strained.