现浇楼板对RC框架结构破坏形式的影响分析

The Effect of SlAbs on the Failure Mode of Reinforced Concrete Frame Structures

结合"5.12"汶川地震的震害调查,考察了现浇钢筋混凝土框架结构产生"强梁弱柱"破坏形式的原因,重点分析了现浇楼板对框架梁抗弯承载力的增强作用,研究表明影响现浇楼板对框架梁抗弯承载力增强程度的主要因素为节点类型、横向梁刚度和侧向位移。为详细研究这些主要因素的影响方式,采用非线性有限元软件ABAQUS对侧向荷载控制下的现浇钢筋混凝土框架结构进行了模拟,分析了不同侧向位移对应的楼板内钢筋应力变化情况,并得出了梁端位置的现浇楼板有效翼缘宽度建议取值方法。

A majority of reinforced concrete frame structure failure patterns resulting from the May 12, 2008 earthquake in Wenchuan County, P. R. China were analyzed. It was found that the main failure mode of frame works was ＂strong beam, weak column＂, which conflicts with the design criteria of ＂strong column, weak beam＂. The cause of this failure pattern was analyzed. A new concept is put forward that should be considered in design work. The over-strength caused by slabs connected monolithically to the beams is analyzed. The joint types, transverse beam stiffness and lateral drift influence the reinforcing effect of the slab. Moreover, a reinforced concrete frame model was simulated using the program ABAQUS. The slab reinforcement stress distributions at different lateral drifts were analyzed and the effective flange width value proposed.