| Frame-supported shear wall structure is one of widely used structural systems in China for architectural style reason, functional requirement and other needs. And the application of frame-supported shear wall structure is to more wide in super high-rise buildings, tower connecting structures, enlarged base structures and other complex high-rise buildings. However, existing research on the failure mechanism is obviously insufficient because of in defect of earthquake experience and research results. Parts of regulations of provisions are not rational and control effect of failure mechanism is limited. Failure mechanism with deficient seismic performance can not avoid completely. As a class of primary structural system in China, failure mechanism of frame-supported shear wall structure is necessary to be comprehended. And it is also reasonable to promote corresponding control measures. Works of this study are followed:(1)4 frame-supported shear wall specimens of 1/4 scale were tested under quasi-static load. Based on the simulation and study of experimental model and other structures, possible failure mechanisms of frame-supported shear wall structures were suggested.(2)Optimal failure mechanisms were proposed for first-story-transfer structure and high-position-transfer structure through comparison of structure capability with different failure mechanism.(3)Influence factors for failure mechaism were studied, and disadvantages of failure mechanism control measures in current provision were disscussed.(4)Failure mechanism control measures were proposed. That is improvement mothord for stiffness control measures based on current provision considering the influence of transfer height, and capacity demand of lateral load resisting members.The study defined optimal failure mechanism of frame-supported shear wall structures and proposed the deficiency of control measures of provisions. And it also raised effective control measures for the sake of plastic story drift control including of improvement mothord for stiffness control measures and capacity demand of lateral load resisting members . Research made the following conclusions:(1)Weakness position is bellow of transfer story for frame-supported wall structures under quais-static load because stiffness of bellow structure is deficient. Frame-supporting column of first-story-transfer structure is mainly shear deformantion and damaged by shear force. Frame-supporting column of high-position-transfer structure is mainly shear and flexural deformantion and damaged by large eccentric compression. However, degeneration of stiffness is obvious for first-story-transfer structure than high-position-transfer structure which has better defortmation capacity and worse bearing capacity. For high-position-transfer structure, weakest positions of frame-supporting column are at top story and first story."Strong Column Weak Beam"mechanism would be realized in middle story of supported frame mostly.(2)Bearing capacity of frame-supported wall structure is inadequate for structures whlie weakness story is below transfer story. And deformation performance is deficient if columns were damaged by shear force for structures with this failure meachnism. Bearing capacity and deformance performance are failimar for structures whose weakness story is upper transfer story or whole story damaged symmetrically.(3)Frame-supporting story not firstly and rapidly failure is optimal failure mechanism for frame-supported shear wall structure. It is not allowed for all structues to achieve the mechanism that frame-supporting story is rapidly failure. And first-story-transfer structure would not allowed to achieve the mechanism that frame-supporting story is firstly failure.(4)Stiffness ratio control measure in provisions for failure mechanism is rational and effective. But limiting transfer story height makes different frailure mechansium for structures designed according to provision,and can not avoid premature or firstly failure of structure under transfer story.(5)Compared to the measure of limit transfer story height, it is more reasonable and effective to limit plastic drift ratio while considering influence of transfer story height to the stiffness ratio control method of specifications.(6)Demand of deformation performance for frame-supporting column is large while stiffness of upper story is relatively large. Demand of deformation performance of column also increases with the height of transfer story. For high-position-transfer structure, increase of bearing capacity of column can decrease demand of deformation performance. For first-story-transfer structure, if the shear-comparison ratio of column is little, demand of column performance would increase. |
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