Research On Deformation Limits Of T-shaped RC Shear Wall Based On Material Strain

Shear wall is usually the first seismic fortification line of high-rise buildings, so its deformation performance is very important for ensuring safety and reducing economic loss. Performance-based seismic design method can not only propose the capacity requirement, but also set a desired deformation limit according to owners’ demands to reduce losses caused by earthquake and to make the structure cost-effective. Nowadays, failure modes and deformation performance index of rectangular cross section RC(reinforced concrete) shear wall are studied by some scholars, but researches on failure modes of T-shaped shear wall are not sufficiently given. The present thesis therefore studies the seismic performance and the deformation performance index limit of T-shaped RC shear wall and the main contents are as follows:(1) The research findings on seismic performance and experimental data pertinent to T-shaped RC shear wall given by domestic and foreign scholars are first summarized and ABAQUS is then applied to simulate mechanical behavior of the specimens. The output load-displacement curve and failure modes are in good agreement with the experimental results, and it thus indicates that the simulation through which the stress state and failure mode of T-shaped RC shear wall are both obtained is reasonable.(2) On the basis of existing codes, by changing shear span ratio, reinforcement ratio, flexural shear ratio, axial compression ratio, and stirrup reinforcement characteristic value, 271 T-shaped RC shear walls are designed to be numerically simulated by ABAQUS. By aid of analyses of the experimental data from 32 T-shaped RC shear walls and the results of the FEM(finite element method) models, the failure mode classification method is then proposed based on further FEM results in this thesis. In order to classify the failure mode of T-shaped RC shear wall and to provide detailed criteria, shear span ratio and flexural shear ratio are deemed as parameters. The failure modes of T-shaped shear wall components determined by the criteria agree well with both the experimental results and the failure modes of the FEM models. Such outcome indicates that the criteria of failure mode regarding to T-shaped shear wall component is accurate and feasible.(3) Considering the description of T-shaped RC shear wall’s deformation characteristics and severity of damage, the seismic performance states of T-shaped shear wall are determined. The components subjected to flexural and flexural-shear failure can be classified into six performance states: intact, slightly damaged, slightly-moderately damaged, moderately damaged, severely damaged, and invalid; the components subjected to shear failure can be classified into two states: intact and severely damaged.(4) The effect of axial compression ratio, flexural shear ratio, shear span ratio, reinforcement ratio, and stirrup reinforcement characteristic value on the deformation performance index of T-shaped shear walls with different failure modes are mainly analyzed. According to deformation characteristics and the failure modes of T-shaped shear wall, the deformation performance index limits of T-shaped shear wall with different failure modes are carried out. They will provide reference to performance-based seismic design.