桥梁结构安全系数取值问题讨论

Discussion on the Value of the Safety Factor of the Bridge Structure

安全系数具有含义明确、便于工程技术人员理解和工程应用等优点。为了方便读者理解和阐释具体的问题,对桥梁结构安全系数取值原则和设计规范中存在的问题进行分析与讨论。首先,从影响结构安全的诸多不确定因素入手,定义了基准安全系数和调整系数;其次,从材料、构件、连接和结构,主要承重结构和桥道结构,上部结构和下部结构,结构约束体系,永久性构件和非永久性构件,施工阶段和运营阶段,结构分析手段,以及荷载取值等角度讨论了安全系数的调整原则;最后,在既定原则的基础上,从结构抗力、荷载作用、破坏模式和分析手段的角度,主要对比分析了桥梁设计规范中的安全系数,讨论了规范中安全系数取值的合理性,并提出了安全系数取值方面存在的问题和建议。

The safety factor has the advantages of clear meaning, ease of understanding, and engineering applications. In order to facilitate readers’ understanding and explanation of specific problems, this study analyzed and discussed the problems existing in the safety factor value principle and design specification of bridge structures. First, starting from many uncertain factors affecting structural safety, this study defines the base-level safety factor and adjustment factor. Second, the adjustment principle of the safety factor was discussed based on material, member, connection and structure, main bearing structure and deck structure, superstructure and substructure, structural restraint system, permanent and non-permanent members, construction stage and operation stage, structural analysis method, and value of load. Finally, based on the established principles, from the perspective of structural resistance, load action, failure mode, and analysis methods, the safety factors of the bridge design specifications were compared and analyzed. Furthermore, the rationality of the safety factor value of the specifications was discussed. In addition, the problems and suggestions for the safety factor value were put forward.