摘要
针对我国中小跨公路桥数量庞大的现状,为了给桥梁安全性分析及运营维护的方向提供参考,以某预应力空心板连续梁桥为例,采用EFAST法进行了公路桥梁全局敏感性分析。该方法考虑了结构材料性能、约束强度及荷载作用3个方面共11个影响因素,从桥梁承载能力的角度建立了3个评价指标;利用有限元仿真分析,通过蒙特卡罗法模拟影响因素对评价指标的影响;为平衡EFAST法的计算代价,引入LSSVM构建代理模型,以有限元计算结果为基础生成大量样本,代入EFAST法得到各个影响因素的敏感性指标。结果表明:对本例预应力连续梁桥,混凝土强度、Ⅱ级钢强度、预应力筋强度、预应力筋面积、结构自重及汽车荷载对各个评价指标均有较高的敏感性,应在不确定性分析及桥梁运营中给予关注;而支座弹性模量、冲击系数、均匀温度荷载对于各个评价指标均呈现较低的敏感性,可在不确定分析中用均值代替以简化计算。
In view of the large number of medium and small span highway bridges in China,in order to provide reference for bridge safety analysis and operation and maintenance,taking a prestressed hollow slab continuous beam bridge as an example,the global sensitivity analysis of highway bridge is carried out by EFAST method.Considering 11 influencing factors of structural material performance,restraint strength and load action,three evaluation indexes are established from the perspective of bridge bearing capacity.Using finite element simulation analysis,Monte Carlo method is used to simulate the influence of influencing factors on the evaluation index.In order to balance the computational cost of EFAST method,LSSVM is introduced to build a surrogate model.A large number of samples are generated based on the results of finite element calculation,and the sensitivity index of each influencing factor is obtained by substituting EFAST method.The results show that the concrete strength,grade II steel strength,prestressed reinforcement strength,prestressed reinforcement area,structural self-weight and vehicle load are highly sensitive to each evaluation index,which should be paid attention to in the uncertainty analysis and bridge operation;however,the elastic modulus,impact coefficient and uniform temperature load of the bearing show low sensitivity to each evaluation index,which can be replaced by the mean value in the uncertainty analysis to simplify the calculation.
作者
张敬雷
王伟
李彤
罗辉
ZHANG Jing-lei;WANG Wei;LI Tong;LUO Hui(Construction Quality Supervision Administration of China Railway Corporation,Being 100844,China;Poly(Wuhan)Real Estate Development Co Ltd,Wuhan 430040,China;School of Civil Engineering&Mechanics,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《土木工程与管理学报》
北大核心
2020年第5期51-56,共6页
Journal of Civil Engineering and Management
基金
国家自然科学基金(51578261)
湖北省技术创新专项重大项目(2017ACA183)
湖北省自然科学杰出青年基金(2017CFA074)。
关键词
EFAST
全局敏感性分析
预应力连续梁桥
评价指标
EFAST
global sensitivity analysis
prestressed continuous beam bridge
evaluation index
