Study On The Effect Of Different Arrangements Of Buckling Restrained Braces In High-rise Shear Wall Buildings On Seismic Performance

As the first line of defense against earthquake in the coupled shear wall structure designing, the coupling beam plays an indispensable role in consuming horizontal seismic energy. Therefore improving the energy dissipation ability of coupling beam will significantly augment the seismic performance of coupled shear wall structures. However if the stiffness of coupling beam is too small, the structure will be destroyed early because of lack of enough carrying capacity. Coupling beams commonly have large span and large section, so it is difficult to fulfill the contradictory between stiffness and ductility. Domestic and overseas scholars, nowadays, have carried out many studies in an effort to enhance the ductility and dissipation capacities of coupling beam such as cross diagonal reinforcement coupling beam, reinforced concrete composite coupling beam and steel coupling beam which are not practical because they are difficult to be constructed, less likely to repair and uneconomical. As an energy-consuming component, buckling-restrained brace(BRB) excels in energy dissipation and is mainly used in column bracing of frame structure. Nevertheless,whether it is able to be applied in coupling beams still requires further study.A series of frame-core tube structure models with coupled shear walls are firstly created through PKPM software, the coupling braces of which are then replaced with BRB and steel truss in the whole building, as the alternatives of common concrete coupling beam. Mode analysis and spectrum analysis are then carried out toward three kinds of structure mentioned above. Pushover analysis is adopted through the finite element analysis software SAP2000 to further study the behaviors of different structures. Studies are made to find the most practical arrangement of BRB by arranging BRB in place of common concrete coupling beam firstly from 8 to 14 floors secondly from 8 to 16 floors which are alternative arranged, thirdly in the whole floors and fourthly in the whole floors except the 8 to 14 floors.The result shows that the application of BRB does not influence the self-vibration characteristics of initial structure, and the seismic performance of BRB is less obvious under frequent earthquake. Under the condition of rare earthquake, BRB reaches the elastoplastic phase and is damaged before shear wall, which will ensure that coupling beam is the first line of defense against earthquake. Also, the application of BRB will significantly drop the inter-story displacement angles and presents better aseismatic performance compared with steel truss coupling beam. Furthermore, only replacing common concrete coupling beam with BRB in which the inter-story displacement angles are large is more cost-effective.