Overturning collapse responses of RC frame-shear wall structures induced by failure of vertical members

Abstract

In this paper, three 1/5 scaled reinforced concrete (RC) frame-shear wall structural models with single shear wall or cross shear walls on each floor were tested to reveal the mechanism of overturning collapse induced by failure of vertical members. A three-dimensional videogrammetric measurement technique based on high-speed cameras was adopted to acquire spatial locations and status of the moving objects. Overturning collapse was obsessed in all the three structural models after partial vertical members were removed. However, although the structural model with cross shear walls overturned, it did not disintegrate, which indicated that existence of the cross shear walls improved integrity of the structure. Meanwhile, a collapse simulation system was developed based on discrete element method (DEM). Collapse processes of the three structural models, including debris stacking, were predicted and effectiveness of removing the vertical components to simulate dynamic effects in the numerical model was verified. Experimental and numerical results revealed that overturning collapse would be initiated when a sufficient number of vertical components were removed and the flexural bearing capacities of the remaining vertical load bearing members could not resist the impact load of the upper structure for an RC frame-shear wall structure. Parametric analysis indicated that the higher the failure was located, the smaller the damage of the lower remaining structure. Moreover, if the remaining vertical load bearing structural members could not support the upper structure of a high rise building due to insufficient compressive bearing capacities, progressive collapse would take place, and cross shear walls played an important role in resisting collapse for the structure.