Study On Bending And Shearing Resistance Demand Of Shear Walls In Low And High Intensity Areas In China

As the most commonly used vertical components of high-rise buildings,RC shear wall is widely used in high-rise buildings.Achieving a reasonable failure mode under strong earthquake is an important method to ensure its seismic performance.The capability design method is used to guide the bending damage happens at the bottom of shear walls and avoid shear failure occur before bending failure in our design codes,so reasonable bending and shear capacity adjustment coefficient is very important.There are many researches on the validity of the magnification coefficient of shear wall,but relevant research was few in China,so the rationality of the magnification and whether the expected results will happen are worth to discuss.At the same time,strong earthquake happens frequently in China,so it is necessary to verify the validity of RC wall design.In this thesis,examples for low intensity area(6 degrees)and the high intensity region(9 degrees)shear wall and frame shear wall structure were designed based on the current standard of China.Elastic-plastic dynamic time history analysis was established to verify the effectiveness of standard seismic capacity design measures;Comparison of bending moment and shear force between shear wall in low intensity and high intensity area were conducted through examples based on preset failure mode.The analysis results show that:(1)For the cases of shearing wall in a frame and coupled shear wall in 6-degree districts,in the rare earthquake,only the beam behaved slightly yield with enough safety margin for the normal section and diagonal section of walls.Under the action of ultra-strong earthquake,the yielding degree of beam from the frame shear wall and shear wall structure were deeper,the shear wall itself had different probability of bending-yielding,and there is no shearing-yielding.To summarize,the overall seismic performance of frame and coupled shear wall is good.(2)For the cases of shearing wall in a frame and coupled shear wall in 9-degree districts,in the rare earthquake,almost all the beams behaved seriously yield,and the curvature ductility coefficient was big too.At the bottom of the shear wall,bendingyielding was observed,but the ductility coefficient was small,the shearing-yielding were not seen in all the walls.To summarize,shear wall can realize the expected failure mode of "strong column and weak beam" and "strong shear weak bending",the overall seismic performance is good.(3)In low intensity area,the demand of moment and shear resistant capacities of shear wall under frame-wall and coupled-wall structure is less than that provided by construction codes.In the high intensity area,the moment amplification coefficient of frame-wall and coupled-wall structure except the strengthening zone in the bottom of the wall is larger than the standard coefficient 1.2,and the shear amplification coefficient fluctuate near 1.3,which is same to the standard coefficient.