震后RC桥墩竖向承载力最优工程需求参数的选取方法  

Selection method of optimal EDPs for post-earthquake vertical load-carrying capacity of RC bridge piers

作　　者：董慧慧[1] 马睿 韩强[1] 杜修力[1] Dong Huihui;Ma Rui;Han Qiang;Du Xiuli(National Key Laboratoryof BridgeSafetyand Resilience,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学桥梁工程安全与韧性全国重点实验室,北京100124

出　　处：《土木工程学报》2024年第4期59-70,共12页China Civil Engineering Journal

基　　金：国家自然科学基金(52278475);北京市教育委员会(KM202210005020)。

摘　　要：桥墩结构的震后竖向承载力是评估梁式桥梁震后通行功能的重要指标,但其难以测量。为了快速定量地评估桥梁结构的震后通行能力,对评估梁式桥梁结构震后竖向承载力的最优工程需求参数(EDP)进行了系统地研究。首先选取与墩柱残余侧移和损伤相关的5个EDPs,通过对考虑了材料不确定性的RC桥墩进行Pushover分析和动力时程分析得到5个EDPs,进一步对震后的桥墩进行Pushdown分析获取震后竖向承载力。然后采用回归模型对所选EDPs与震后竖向承载力损失比的关系曲线进行回归分析,选取竖向承载力损失比关系曲线的最优回归模型为在ln(x)-y坐标系中的正态累积函数模型,进一步通过最优EDP评价准则对评估竖向承载力损失比的5个EDPs进行评价分析。评价结果表明:当考虑震后可计算性时,峰值侧移率最优;当考虑震后可测性时,残余侧移率最优;当考虑余震时,改进的Park-Ang指标最优。通过选取的最优EDP可以建立桥梁结构功能指标与抗震性能指标之间的联系,为进一步发展和完善桥梁结构的抗震韧性评估和设计提供参考。The post-earthquake vertical load-carrying capacity is an important indicator reflecting the traffic flow capacity of a girder bridge after an earthquake.However,it is difficult to quantify the indicator in the post-earthquake.To rapidly assess the traffic flow capacity of a bridge,the optimal engineering demand parameter(EDP)for post-earthquake vertical load-carrying capacity assessment is comprehensively investigated in this work.Five EDPs related to the residual drift and the damage level of bridge piers are first selected.Subsequently,nonlinear time-history analysis and pushover analysis are performed for RC bridge piers considering the material uncertainty to obtain the EDPs.On this basis,the post-earthquake vertical load-carrying capacity for RC bridge piers with residual drift and damage is obtained by pushdown analyses.The normal cumulative function in the In(x)-y coordinate system is determined as the optimal model,through regression analysis.Based on the performance criteria of the optimal EDP,an assessment on the optimal EDP of post-earthquake vertical load-carrying capacity is conducted.The findings are as follows:(1)The optimal EDP is the maximum drift ratio when the measurability is not considered.(2)The residual drift ratio is determined as the optimal EDP if the measurability is taken into account.(3)Taking into account the effect of aftershocks,the modified Park-Ang damage index is the optimal EDP.The correlation between the bridge functionality and seismic performance can be established by the optimal EDP,and the optimal EDP can provide references for further development and improvement of the seismic resilience assessment and the seismic design of bridges.

关 键 词：桥墩 震后通行能力 竖向承载力损失 最优EDP 残余侧移率 损伤程度 

分 类 号：TU997[建筑科学—市政工程]