钢管混凝土桥墩动力时程分析及累积损伤评估

Dynamic time-history analysis and cumulative damage assessment of concrete-filled steel tube bridge pier

为了研究钢管混凝土桥墩的抗震性能并评估桥墩在地震作用下的累积损伤,对比分析了不同累积损伤模型的差异性,提出了一种基于损伤指标的钢管混凝土桥墩地震累积损伤评估方法。基于纤维截面模型,对某钢管混凝土桥墩在不同地震动强度下进行了横桥向动力时程分析,并从概率角度对桥墩的累积损伤进行评估。结果表明:对于抗震设防烈度为7度的桥墩,在相当于7度E1地震作用下处于基本完好状态,在相当于7度E2地震作用下没有发生严重破坏或失效破坏,在两种超罕遇地震作用下的失效概率分别为15.7%和27.14%,满足抗震设防要求。研究结果可为实际工程中钢管混凝土桥墩的抗震性能评估提供参考。

In order to study the seismic performance of concrete -filled steel tube （CFT） bridge piers, and assess their cumulative damage under earthquake action, different cumulative damage models were analyzed. The distinction of different cumulative damage models was comparatively analyzed and a damage index -based seismic cumulative damage of CFT bridge pier was proposed. On the basis of fiber section model, dynamic time -history analysis of a CFT bridge pier under different earthquake intensities was carried out in the transverse direction of the bridge. A cumulative seismic damage assessment from the perspective of probability was also presented. The results show that for the Intensity 7 fortification zone, the pier is in perfect condition under Intensity 7 E1 earthquake action. Under Intensity 7 E2 earthquake action, pier has no serious damage or failure damage, however, the failure probability is 15.7% and 27.14%, respectively, under two ultra rare earthquakes. The results indicate that, the bridge pier can meet the demands of seismic fortification. The research provide a reference for seismic performance assessment of the CFT bridge pier in practical engineering.