Design Method And Seismic Fragility Of Self-Centering Concrete Shear Wall With Friction Devices

Self-centering concrete shear wall with friction devices (short for self-centering shear wall) is a novel structure to control structural response under seismic action and to restore the original location. In order to study the mechanical behaviors of the structure, theoretical, experimental and numerical study of the structure were investigated, which showed that the structure possesses excellent seismic performance. To promote engineering application of self-centering shear wall, performance-based seismic design mothed of the structure is done and its validity is proved through nonlinear time history analysis, besides, seismic fragility and application performance of the structure are analyzed. The main work are summarized as follow:(1) Performance-based seismic design method of self-centering shear wall is explored. Seismic performance level of the structure and the corresponding limit state are identified. Layout of the structure and dimension of element are preliminarily determined on the basis of site classification and fortification intensity. Prestress, friction force and reinforcement of the structure are calculated to satify the corresponding seismic performance level under design earthquake action and strong earthquake action.(2) The dynamic and time history analysis of self-centering shear wall structure is studied. Finite element model of the designed structure is built. Seven selected ground moton records are adjusted among frequency domain to match the design spectrum. Interstory drift, displacement at the floor level and prestress are recorded during nonlinear time history analysis, furthermore, the output comparison figures under the design earthquake action and strong earthquake action are displayed.(3) Seismic fragility of self-centering shear wall is analyzed. The fundamental principle of structural seismic fragility analysis and incremental dynamic analysis were presented. Seismic performance level of structure, amplitude modulation method of ground motion, intensity measure of ground motion and damage measure of structure are determined. Incremental dynamic analysis of the structure is completed based on forty selected earthquake records according to site classification. Discreteness of the data is evaluated by quantile curves. Seismic fragility curves are plotted in accordance with regression analysis of the data.(4) Retrofit application of self-centering shear wall is introduced. Self-centering shear walls were applied to retrofit a concrete frame structure of five floors. Dynamic characteristic test of retrofitted structure is applied as the reference to finite element model. Incremental dynamic analysis of unreinforced and reinforced structure are implemented to analyze and compare the seismic fragility of unreinforced and reinforced structure.The above work provide references to promoting the extensive application of self-centering shear wall, increasing the seismic performance, reducing the structural damage and cost of post-earthquake rehabilitation.