关键构件失效后钢骨超高强混凝土框架抗连续倒塌能力分析

Analysis of Collapse Resistant Capability of Steel Reinforced Ultra High Strength Concrete Frame after Key Component Failure

基于汶川地震后钢筋混凝土框架震害调查结果,选取首层角柱区域(包括框架柱、与该柱相连的节点)为关键构件,利用有限元分析软件ABAQUS,以抽除点位移、相邻构件轴向荷载为参考数据,对关键构件失效后钢骨超高强混凝土框架抗连续倒塌能力进行分析,讨论了建筑高度、地震波作用方向、有无填充墙、框架柱混凝土强度等级对剩余结构抗连续倒塌能力的影响。结果表明:1随着建筑高度的增加,框架结构抽除点处竖向位移的最大值略下降,首层相邻柱轴向荷载增加明显,框架结构易发生连续倒塌;2框架结构首层角柱区域失效后,Y向地震波作用下剩余结构震荡较大,抗震性能降低,易发生连续倒塌;3设置填充墙的框架结构,抽除点位置处竖向位移较小,结构整体的震荡不大,相邻构件的轴向荷载增长幅度减小,一定程度上提高了框架结构的抗连续倒塌能力;4框架柱使用强度等级较高的混凝土,一定程度上可以减小抽除位置处竖向位移,采用内置钢骨的超高强混凝土柱可提高框架结构抗连续倒塌能力。

Based on the earthquake damage investigation results of reinforced concrete frame in the Wenchuan earthquake, the corner column area of the first floor including frame column and adja- cent joint is chosen as the key component. The finite element analysis software ABAQUS is used. The displacement at the removed position and axial load of the adjacent column are selected as reference data, and the collapse resistant capability of the steel reinforced ultra high strength concrete （SRUHSC） frame after key component failure is analyzed. At the same time, effects of building height, earthquake wave direction, infilled wall, and strength grade of column concrete on the collapse resistant capability of residual structure are discussed. The results show that： （1） Vertical displacement at the removed position falls slightly, axial load of the adjacent column in- creases significantly, and frame structure collapse will happen easily with the increase of building height. （2） The shake of the residual structure becomes more obvious, seismic performance re- duces, and the collapse will appear easily under the Y direction earthquake ground motion after the corner column area failures. （3） Vertical displacement at the removed position is small, the shake becomes insignificant, axial load of the adjacent column grows slowly, and the collapse re- sistant capability can be improved after the infilled wall is installed in the frame structure. （4） The vertical displacement at the removed position can be decreased and the collapse resistant ca- pability can be increased after higher strength concrete column is used in frame structure, espe- cially when the steel reinforces the ultra high strength concrete column.