Study On Seismic Behavior Of Reinforced Concrete Non-planar Beam-wall Joints

Reinforced concrete non-planar beam-shear wall joint is an important connection form in frame-tube structures, but it is still lack of study. Seismic performance of this kind of joint is studied in this thesis through experiments as well as nonlinear finite element analysis.Six specimens of non-planar beam wall joints were tested under cyclic vertical loads on the beam end with axial force on the top of the wall. Under axial force and cyclic vertical loads, cracks developed on the wall and spread around the beam but did not penetrate through the wall. Shear wall failed due to the combination of shear stress and compression stress. At the maximum load, the specimens with larger beam width, part of the tensile vertical reinforcement in front of the wall had yielded, but none of the reinforcements in the back of the wall had yield .Failure occurs mainly at the end of beam and wall, and also on the front surface of wall. Wall below the beam failed seriously. Concrete spalled off and some of the vertical reinforcements in the wall buckled. The back surface of the wall cracked slightly and cracks mainly located around the beam. The ductility of the specimen was small but the deformation capacity was large. The width and the height of the beam section and the slab had positive effect on the ultimate strength and on the energy dissipation capacity of the specimens. The slab increased the wall strength by 20%, and the larger section and the higher capacity. By means of linear finite element analysis, the influence of the width and height of the beam cross-section and on the effective width of the shear wall was studied. A formula of effective flexural width was developed based on the regression analysis. Non-linear finite element analyses were also carried out and the stress distribution pattern in the wall was consistent with the experimental results.According to the ACI-95 formula on the slab strength of the slab-column connections under cyclic horizontal loads on the column , formula of wall strength under axial force and non-planar moment was developed. The calculation results had good agreement with experiment results. The formula can be used to evaluate the flexural strength of shear wall under non-planar moment.