装配式混凝土空心板梁桥结构冗余性水平评估  

Assessment of Redundancy Level of Prefabricated Concrete Hollow Slab Bridge

作　　者：李琦[1] 李杰[1] 冷艳玲[2] 

机构地区：[1]新疆交通职业技术学院,新疆乌鲁木齐831401 [2]交通运输部公路科学研究院,北京100088

出　　处：《公路交通科技》2018年第3期46-51,57,共7页Journal of Highway and Transportation Research and Development

基　　金：交通运输部建设科技项目(2013 318 223 04)

摘　　要：目前对桥梁结构的安全评估停留在构件层次。对于冗余性低的桥梁结构,考虑系统行为后,结构的可靠度会降低,表现在某个局部破坏可能会造成结构体系整体坍塌。国内外几座装配式混凝土空心板梁桥垮塌事故警示该桥型的冗余性较差,铰缝失效可诱发桥梁坍塌事故。由于桥梁结构系统的受力情况复杂,荷载传输路径不易模拟,且必须考虑几何非线性和材料非线性,需要进行精细化的有限元非线性分析。为了校准有限元模型,以一座装配式混凝土模型桥梁为研究对象,利用Midas Civil有限元软件的Pushover分析方法,分别得到了单梁、桥梁结构系统在集中荷载作用下的荷载位移响应。通过有限元分析结果与破坏试验结果的对比分析,校准了有限元模型,证明了利用Midas Civil梁格法进行pushover非线性分析计算桥梁结构体系承载能力可获得满意结果,保证了分析结果的可靠性。然后基于有限元分析结果,计算了模型桥梁的冗余性水平。计算结果表明,该模型桥梁的冗余因子为0.73,低于相关阙值1.30,表明该模型桥梁的冗余性水平低于相关阙值,验证了对该桥型冗余度低的推定。Currently, the safety evaluation of highway bridges is at the component level. Low redundant bridge structures usually lead to lower reliability considering the system behavior, partial damage may cause the damage of the whole structure system. The catastrophic events of prefabricated concrete hollow slab bridges at home and broad warned that the redundancy of this bridge type may be too weak, and the failure of hinge joint may lead to the collapse of bridge structures. Due to the complex loading scenarios of the bridge structure system, the load path is not easy to simulate, and the nonlinearity of geometry and material properties should be considered, the refined nonlinear finite element analysis should be adopted. In order to calibrate the finite element model, Midas Civil finite element software is used to conduct pushover nonlinear analysis of a prefabricated concrete model bridge, the load-displacement response curves of the individual beam and the bridge system under concentrated load are obtained respectively. The FE model is calibrated by comparison of the FE analysis result and the destructive testing result. It is verified that Midas Civil grillage method could calculate the load bearing capacity of the bridge system accurately through pushover nonlinear analysis, thus the reliability of the analysis result is guaranteed. Then, the finite element analysis result is used to compute the redundancy level of the model bridge. The calculation result shows that the redundancy factor of the model bridge is 0.73, which is lower than the recommended value of 1.30. It shows that the redundancy level of the bridge does not meet the redundancy related criterion, it verified that the redundancy of this bridge type is inadequate.

关 键 词：桥梁工程 结构冗余性 桥梁评估 装配式空心板梁桥 铰缝损伤 

分 类 号：U447[建筑科学—桥梁与隧道工程]