超2000 m级悬索桥重力式锚碇抗滑安全度设计方法  

Anti-slip Safety Design of Gravity Anchorage of Suspension Bridges with Over-2000-meter Main Spans

作　　者：熊文[1] 王仁贵[2] 汪涛 魏乐永[2] 周小燚 XIONG Wen;WANG Ren-gui;WANG Tao;WEI Le-yong;ZHOU Xiao-yi(School of Transportation,Southeast University,Nanjing 211189,Jiangsu,China;CCCC Highway Consultants Co.Ltd.,Beijing 100088,China)

机构地区：[1]东南大学交通学院,江苏南京211189 [2]中交公路规划设计院有限公司,北京100088

出　　处：《中国公路学报》2024年第4期166-175,共10页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(52378135,52022021,51978160);江苏省重点研发计划项目(BE2021089)。

摘　　要：超2000 m级悬索桥已超过现行桥梁设计规范的适用范围,传统安全系数法仅从均值或标准值角度反映设计安全度,未能真实反映抗力小于荷载导致失效的概率或风险。基于荷载、抗力以及设计关键参数的数据统计特征与变异性,利用可靠度分析理论,对悬索桥重力式锚碇滑移构建承载能力极限状态设计方程,重点计算基于目标可靠度的抗力项分项系数合理取值,并推导目标可靠度等效的抗滑安全系数表达式。最后以主跨2300 m世界第一跨径悬索桥为背景工程,构建超大跨径悬索桥重力式锚碇抗滑实用设计表达式,并与传统安全系数设计方法进行安全度对比分析。结果表明:利用极限状态(分项系数)设计方法,与现行规范锚碇设计方法相比,可显著降低超大跨径悬索桥重力式锚碇抗滑设计等效安全系数取值,大幅提升其安全设计的科学性与经济性,并为编制超2000 m级悬索桥设计规范提供基础理论与技术支撑。Design specifications for bridges are not applicable to over-2000-m-long suspension bridges.The traditional design method with overall factors of safety reflects the safety margin of the bridge using average or standard values,and the failure probability calculated by resistance and load effects cannot be considered in the method.In this study,the statistical characteristics and variability of the load,resistance,and design parameters of the anchorage are discussed.Based on a reliability analysis,a limit state equation was established for the sliding of the gravity-type anchorage(GTA)of suspension bridges.Given the target reliability index,partial factors of resistance were discussed,and the expression of the equivalent factor of safety was deduced.Considering the world's longest suspension bridge spanning 2300 m as an example,design equations with partial factors were established for the sliding resistance of the GTA of super-long-span suspension bridges,and a comparison was performed with the traditional design method with the overall factors of safety.The results show that the equivalent factors of safety considering the sliding of GTAs are significantly decreased by the limit state design method with partial factors.This design method is highly scientific and cost-effective.It also provides a theoretical basis and technical support for the design specifications of over-2000-m-long suspension bridges.

关 键 词：桥梁工程 超2000 m悬索桥 设计方法 锚碇 抗滑安全度 可靠度 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]