The Stability And Elastoplasticity Of Reinforced Concrete Shear Wall

Reinforced concrete shear wall has large lateral rigidity,and it is the main lateral load resistant component in high-rise building structures.The analysis and study of the stability and the elastoplastic problems of the shear wall in its process of loading can provide guidance for the structural design of high-rise building structures.The main contents are as follows:(1)The calculation unit of shear wall was extracted from actual structures with the reasonable simplification of the boundary of shear wall.By establishing model of orthotropic slab with two simply supported sides and two free sides,the stability of shear walls under vertical loads was analyzed.The critical stress formula for shear walls at buckling failure was derived through the theoretical analysis based on the principle of stationary potential energy.And the influences of the wall's size and reinforcement ratio of the section on its stability were studied.Then,the effective measures to improve the stability of shear walls were put forward and design suggestions for the stability of shear wal s were provided.(2)The stress and strain distributions of shear walls under vertical loads and concentrated lateral forces on the top were derived using the semi-inverse method of stress function in elastic theory.The deformation law of shear wall along the three directions of height,width and thickness was obtained.By analyzing the displacement variation along wall's height direction,it was found that the transversal section at any height of the shear wall could be regarded as a plane,but it is no longer perpendicular to the normal of the deformed transversal section.Furthermore,the distribution of shear deformation on the whole wall was analyzed,and the influence of aspect ratio,axial compression ratio and lateral force on shear deformation were obtained.(3)Timoshenko's deep beam theory considering first-order shear deformation was used to derive two equations for calculating the generalized displacement of shear walls in integral form,and a formula for calculating the shear rigidity of shear wal s was derived.(4)The cracking stage of shear wall was analyzed,the stress and strain distributions at crack on the transversal section are obtained,the calculation formula of cracking moment was deduced,and effective measures to delay the cracking of shear wall under lateral force were put forward.(5)Steel bar and concrete were considered as ideal elastic-plastic materials,and the stress and strain distribution of critical transversal section of shear wall at ultimate state were rationally simplified according to the test results.The formula for calculating the ultimate bearing capacity of shear wall was derived after the suitable yield criterion for concrete was determined.The theoretical calculation results were in good agreement with the test results.