大跨度劲性骨架拱桥Pushover 分析方法  

Pushover Analysis Method for Long⁃span Stiff Skeleton Arch Bridge

作　　者：谢开仲 梁栋 谢松茂 魏勇 XIE Kaizhong;LIANG Dong;XIE Songmao;WEI Yong(College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Key Laboratory of Disaster Prevention,Mitigation and Engineering Safety,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院,南宁530004 [2]广西大学防灾减灾与工程安全重点实验室,南宁530004

出　　处：《铁道建筑》2022年第9期87-92,共6页Railway Engineering

基　　金：国家自然科学基金(51868007,51738004);国家重点研发计划(2019YFC1511103)。

摘　　要：以一座铁路上承式钢管混凝土劲性骨架拱桥为对象,对Pushover方法在抗震性能评估中的适用性进行研究。首先,根据桥梁的结构特点选取适宜的加载模式以及控制节点进行Pushover分析得到结构的能力谱曲线;然后,根据选取的地震波建立需求谱曲线,基于能力谱曲线迭代求解结构的性能点,将性能点求解的拱肋线形、应力与非线性时程分析结果进行对比验证;最后,基于刚度退化模型提出劲性骨架拱桥地震损伤模型,采用损伤指数对劲性骨架拱桥地震损伤程度进行量化,并对不同地震烈度下结构地震损伤进行评估。结果表明:拱肋线形Pushover方法与非线性时程分析的计算结果比较接近;两种方法在拱肋应力突变位置以及屈服位置比较接近;结构在0.3g、0.4g地震作用下基本完好,0.8g时产生了轻微损伤,4.0g地震作用下桥梁严重破坏。Pushover方法与非线性时程分析结果的对比验证了Pushover方法应用于大跨度劲性骨架拱桥抗震性能评估的可行性。Taking a railway deck type concrete-filled steel tube(CFST)stiff skeleton arch bridge as the object,the applicability of Pushover method in seismic performance evaluation was studied.Firstly,according to the structural characteristics of the bridge,the appropriate loading mode and control nodes were selected for Pushover analysis to obtain the capacity curve of the structure.Then,the demand spectrum curve was established according to the selected seismic wave,and the performance points of the structure were iteratively solved based on the capacity spectrum curve.The alignment and stress of arch rib solved by performance point were compared with the results of nonlinear time history analysis.Finally,based on the stiffness degradation model,the seismic damage model of the stiff skeleton arch bridge was proposed.The damage index was used to quantify the seismic damage degree of the stiff skeleton arch bridge,and the structural seismic damage under different seismic intensity was evaluated.The results show that the calculation results of Pushover method for arch rib alignment are close to those of nonlinear time history analysis.The two methods are close to each other in calculating the stress mutation position and yield position of arch rib.The structure is basically intact under 0.3g and 0.4g earthquakes,slightly damaged at 0.8g earthquakes,and severely damaged under 4.0g earthquakes.The feasibility of applying Pushover method to seismic performance evaluation of long-span stiff skeleton arch bridges is verified by comparing the results of Pushover method and nonlinear time history analysis.

关 键 词：铁路桥梁 PUSHOVER方法 数值模拟 钢管混凝土劲性骨架拱桥 抗震评估 

分 类 号：U448.13[建筑科学—桥梁与隧道工程]