钢筋混凝土框架结构抗震超强系数分析

Seismic overstrength factors for reinforced concrete frames

基于我国建筑抗震规范要求设计的14栋代表不同抗震特征要求的多高层规则钢筋混凝土框架,通过静力弹塑性分析详细地评估了框架结构的体系超强能力。分析中采用与抗震规范等效静力地震作用效应分布模式相同的单调递增侧向荷载,以二维平面框架为分析对象。分析结果表明地震分区对超强系数的影响较大;有填充墙框架比无填充墙框架的超强能力明显要大;内框架的超强能力比外框架的超强能力大;超强系数随框架楼层数的增加而减小。

Based on 14 multistory reinforced concrete frames of various seismic characteristics, this paper assesses, by means of inelastic static pushover analysis, the seismic overstrength capacity of the frames designed according to china＇s code for seismic design of buildings. In analysis, the lateral force profile is designated proportional to the lateral equivalent horizontal load distribution specified in the seismic code and increases monotonically, and the individual two-dimensional frame is employed to analyses the structural overstrength capacity. Analysis results indicate that the overstrength factor is predominantly influenced by seismic fortification intensity; the overstrength factor also depends strongly on the infill wall, the overstrength factor of the frames with infill wall is clearly larger than that of the frames without infill wall. Similarly, the overstrength factor of interior frames is commonly greater than that of exterior frames, moreover the overstrength factor is decreased as the number of stories is increased.