Research On Seismic Shear Capacity Of Reinforced Concrete Structural Walls With Flanges

Reinforced concrete shear walls are critical members in modern high-rise buildings. In process of the structural wall systems, Frame-structure wall systems and the frame-core systems resist the earthquake, walls are important for ensuring lateral stiffness, contributing to basic earthquake resistance and energy dissipation. In order to ensure the ductile behavior of walls in structures designed according to ductility concept, shear failure should be prevented before walls response nonelastically to an expected extent under strong ground motion. Therefore, in the seismic design of ductile wall, it is critical to definite appropriate formula for calculating seismic shear capacity.By far, without any tests on the seismic shear behavior of walls or referring to any relevant test abroad, the formula for calculating seismic shear capacity of walls in Chinese Code GB 50010-2002 is developed only based on the tests of shear behaviors of nonsesmic walls, and judgments of professionals. In order to improve the weakness in the shear design of critical earthquake-resistant members—shear walls, and check ulteriorly the seismic behaviour of the concrete structure walls, the Civil Engineering College of Chongqing University undertakes the project of test investigations on shear behaviors of seismic shearwalls in the 6th batch of research subjects on the Code.By analyzing the relevant experimental results from foreign countries, we found what are still limited are tests on shear behaviors of I-shape and T-sharp shear walls with constant axial compression force. Under such background, Two I-shape shearwalls with relatively big scale had been designed and tested under reversed cyclic horizontal forces by our team, Four specimens with the aspect ratio 1.5, include two I-sharp and two T-sharp, are designed and tested under reversed cyclic horizontal forces, Constant axial forces maintained throughout tests. During the tests, the stresses of the reinforcement at relevant places were traced, and the hysteric curves of the specimens are gained, and the flexural and shear deformations are tied to be traced and recorded throughout the tests. Finally, one of the specimen destroied abnormally for the equipments'reason, and the other three specimens failed in the expected way, that is, fail in shear mode after the flexural tensile reinforcement yielded and the specimens reach a certain displacement ductility. The shear reinforcement ratio and the concrete strength of the three specimens are different. The test result (the ductility of the specimens gained in the tests) are of important value for the improvement and revising of our formula on shear strength of seismic shearwalls.At the end of the thesis, comparisons on the test results and the values predicted by《concrete structure design code》GB50010 (not considering reliability) are carried out .We find that the formula of the code is on the safe side as a whole.