大跨度刚构桥悬臂施工阶段挠度可靠度研究  

Research on Deflection Reliability of Long Span Rigid Frame Bridge during Cantilever Construction

作　　者：农升伟 NONG Sheng-wei(Guangxi Zhuang Autonomous Region Guangxi West Highway Development Center,Nanning 530007,China)

机构地区：[1]广西壮族自治区桂西公路发展中心,南宁530007

出　　处：《价值工程》2024年第17期144-147,共4页Value Engineering

摘　　要：为确定考虑结构时变可靠性控制下大跨度刚构桥不同悬臂施工阶段悬臂端容许挠度偏差范围,提出了一种考虑悬臂施工标高控制的刚构桥时变可靠度分析方法。基于施工阶段容许挠度偏差建立了刚构桥结构功能函数,以某大跨度刚构桥为例,采用支持向量机与蒙特卡洛模拟法计算了不同悬臂阶段下各挠度允许偏差范围的结构可靠度指标。结果表明:在一定范围内,不同悬臂施工阶段中标高控制可靠度指标均与悬臂端容许挠度偏差呈现正相关关系;当悬臂端容许挠度偏差越小时,受随机变量不确定性影响,结构可靠度指标较低;以可靠度指标4.7为安全控制要求时,短、中、长悬臂施工阶段的容许挠度偏差最低限值分别为3.38mm、7.42mm、16.88mm。In order to determine the allowable deflection range of the cantilever end of a long-span rigid frame bridge at different cantilever construction stages under the control of structural time-varying reliability,a time-varying reliability analysis method of rigid frame bridge considering the control of cantilever construction elevation is proposed.Based on the allowable deflection deviation in the construction stage,the structural function of rigid frame bridge is established.Taking a long-span rigid frame bridge as an example,the structural reliability indexes of each allowable deflection range in different cantilever stages are calculated by using support vector machine and Monte Carlo simulation method.The results show that:within a certain range,the elevation control reliability index in different cantilever construction stages has a positive correlation with the allowable deflection deviation of the cantilever end;When the allowable deflection deviation of the cantilever end is smaller,the structural reliability index is lower due to the uncertainty of random variables;When the reliability index 4.7 is taken as the safety control requirement,the minimum allowable deflection deviation limits of short,medium and long cantilever construction stages are 3.38mm,7.42mm and 16.88mm respectively.

关 键 词：刚构桥 悬臂施工 标高控制 挠度 可靠度指标 

分 类 号：U448.23[建筑科学—桥梁与隧道工程]