基于可靠性的桥梁结构弹塑性极限承载力评估  

Elastic-Plastic Ultimate Bearing Capacity Evaluation of Bridge Structure Based on Reliability

作　　者：刘剑[1] 刘永建[2] 

机构地区：[1]中南林业科技大学土木工程与力学学院,湖南长沙410004 [2]长安大学桥梁与隧道陕西省重点实验室,陕西西安710064

出　　处：《公路工程》2015年第5期60-64,81,共6页Highway Engineering

基　　金：国家自然科学基金项目(51408615);国家自然科学基金项目(51178473)

摘　　要：由于目前桥梁结构弹塑性极限承载力评估缺乏确实可行的方法,给桥梁结构的承载力评估带来了不便。基于可靠度理论和单一系数设计准则提出了一种桥梁结构极限承载力评估方法,将目标可靠度指标转换为易被工程设计人员所接受的极限荷载安全系数,并给出了不同安全等级的桥梁结构在不同状态及破坏模式下的相应安全系数容许取值,为桥梁结构的弹塑性极限承载力评估提供了依据。并采用此方法对东江大桥-刚性悬索加劲钢桁桥的最大悬臂阶段及成桥阶段进行评估,结果表明大桥在两阶段下的弹塑性极限承载力均满足要求,同时也验证了该方法简单实用。Due to lack of feasible method on elastic-plastic ultimate bearing capacity evaluation at present,it is inconvenient to evaluate ultimate bearing capacity of bridge structure.A new method was put forward based on the reliability theory and the single factor design criteria.The target reliability index was converted to the form of safety coefficient easily accepted by engineering designer,and gave the corresponding safety coefficient values of bridge structure under different status and failure mode,which could provide reference for elastic-plastic ultimate bearing capacity evaluation of bridge structure.And then this method was used to evaluated the elastic-plastic ultimate bearing capacity of Dongjiang bridge,a steel truss bridge stiffened with rigid cables,in the longest cantilever stage and the finished stage,the result show that the ultimate bearing capacity of this bridge meet the requirements in both statuses,and also verify the evaluation method is simple and practical.

关 键 词：可靠性 弹塑性 极限承载力评估 单一系数设计准则 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]