改进响应面法计算钢筋混凝土框架体系可靠度

钢筋混凝土框架结构体系可靠度是评定结构抗震性能的重要指标,也是对既有结构进行加固的评估基础。以框架底层柱端极限弯矩承载力作为参考变量可有效评估框架结构体系可靠度,该方法采用Pushover静力推覆分析,通过研究框架结构底层柱端极限弯矩承载能力对Pushover曲线的影响规律,由Pushover曲线上的基准点推广得到结构失效响应面,从而计算出结构体系可靠度。应用该方法对一榀钢筋混凝土框架进行了体系可靠度计算,计算结果与直接响应面法和蒙特卡洛法分析结果进行对比,结果表明,该方法计算快捷,且能够很好地评估出框架体系抗震可靠度。

SYSTEM RELIABILITY CALCULATION OF RC FRAME STRUCTURES BY IMPROVED RESPONSE SURFACE METHOD

Structural system reliability is an important indicator for seismic performance assessment of reinforced concrete (RC) frame structures and the evaluation basis for reinforcement of existing RC building structures. This paper is concerned with the development of a method to evaluate the structural system reliability of RC frame structures which can be effectively evaluated by using the ultimate moment carrying capacity at the ends of the bottom columns of RC frame structures. The pushover method is first employed to analyze RC frames, and by studying the influence of the ultimate moment carrying capacity of the bottom columns on the Pushover curve the structural failure response surface can be calculated from the reference points on the Pushover curve. This method is applied to estimate the system reliability of a RC frame. The numerical results obtained using the current method are compared with those predicted using the response surface method and Monte Carlo method. It is demonstrated that the proposed method is more computationally efficient and better in system reliability assessment.