钢筋混凝土桥梁地震易损性评估模型设计

Design of a Seismic Vulnerability Assessment Model for Reinforced Concrete Bridges

摘要:

桥梁作为交通中不可或缺的一部分，对其地震易损性进行研究具有现实意义。针对当前桥梁地震易损性分析方法存在准确性待提升的问题，提出基于模糊评定的钢筋混凝土桥梁地震易损性评估模型。以桥梁结构层次、材料层次及边界层几方面为主对桥梁评估过程中的不确定性参数进行分析。以分析结果为依据，考虑到桥梁损失是一个比较模糊的概念，引入模糊数学中的模糊评定方法对桥梁地震易损性进行评估。融合位移下桥梁支座损伤分析、能量下桥墩损伤分析、周期下桥梁结构整体损伤分析，构建可以反映钢筋混凝土桥梁由局部到整体的多层次模糊易损性评估模型。通过实验对所建模型进行验证，结果显示：在纵向只发生轻微破坏，且轻微破坏的概率较小，基本处于完好状态。而在横向，发生轻微破坏的概率较大，甚至还可能发生中等破坏。在地震作用下，桥梁破坏也基本以轻微破坏和中等破坏为主，严重破坏的概率很小。

Abstract:

Given that the vulnerability evaluation of bridges is indispensable for traffic hazard assessment, it is of practical significance to study the seismic vulnerability of bridges. Aiming to improve the accuracy of the current seismic vulnerability analysis methods of bridges, this study proposes a seismic vulnerability assessment model of reinforced concrete bridges based on fuzzy evaluation. The uncertain parameters in the bridge evaluation process are analyzed from the aspects of the bridge structure level, material level, and boundary layer. Based on the analysis results, considering that bridge loss is a relatively fuzzy concept, the fuzzy evaluation method in fuzzy mathematics is introduced to evaluate the seismic vulnerability of bridges. The damage analysis of bridge supports under displacement, the damage analysis of piers under energy, and the overall damage analysis of bridge structures under a certain period are combined. Then a multi-level fuzzy vulnerability assessment model is constructed. The experimental results show that in the longitudinal direction, only slight damage occurs, and the probability of slight damage in this direction is small. In the transverse direction, the probability of slight damage is higher, and moderate damage may even occur. Under earthquake action, the bridge damage is mainly slight failure and moderate failure, and the probability of serious damage is very small.