摘要
【目标】为了研究实测随机车流荷载效应对独柱墩梁桥抗倾覆稳定性的影响,对实测汽车荷载的倾覆效应进行统计分析,在此基础上开展基于目标可靠指标的抗倾覆稳定性研究。【方法】首先,基于广东省某大桥动态称重系统进行车流数据统计,并采用蒙特卡罗法模拟随机车流;其次,结合修正倾覆轴法和影响线加载法获得了独柱墩梁桥在随机车流荷载下的倾覆效应,将其与规范车道荷载下的倾覆效应进行对比分析;最后,结合桥梁结构自重的概率统计模型,建立抗倾覆分析随机性模型,提出基于目标可靠指标的抗倾覆稳定性分析方法。【结果】基于修正倾覆轴法计算得到的桥梁抗倾覆稳定性系数误差较小,该方法可较为准确地评估独柱墩梁桥的抗倾覆承载能力;独柱墩梁桥的倾覆效应比与跨数和跨径呈正相关;在目标可靠指标5.2的条件下,基于随机性分析模型计算得到的抗倾覆稳定系数对于曲线桥和直线桥分别为2.29和1.26。【结论】独柱墩梁桥基于随机性分析模型计算得到的抗倾覆稳定性系数小于确定性分析模型;确定性分析模型由于未能考虑荷载效应的随机性而高估了独柱墩梁桥的抗倾覆稳定性;随机性分析模型通过将抗倾覆效应和倾覆效应当作随机变量处理,能够更为准确地评估独柱墩梁桥的抗倾覆稳定性及其安全储备。
[Objective]To investigate the influence of measured random traffic loads on stability of single-column pier girder bridges against overturning,the statistical analysis on overturning effects of measured vehicle loads were conducted.Based on this,the study on stability against overturning based on target reliability indicators was carried out.[Method]First,the traffic flow statistics were collected by using weigh in motion(WIM)system at a bridge in Guangdong,China.Monte Carlo simulation was employed to simulate random traffic flows.Subsequently,the overturning effects of single-column pier girder bridges under random traffic loads were obtained by using the modified overturning axis method and the influence line loading method.These effects were compared with those under standard lane loads.Finally,a probabilistic model of bridge structure dead load was combined to establish the randomness model for overturning stability analysis.A method for analysis on stability against overturning based on target reliability indicators was proposed.[Result]The overturning stability coefficient of bridges calculated by using the modified overturning axis method has a relatively small error.This method can accurately assess the overturning bearing capacity of single-column pier girder bridges.The overturning effect ratio of single-column pier girder bridges is positively correlated with the number of spans and span-length.With the target reliability indicator of 5.2,the overturning stability coefficients calculated with random analysis model are 2.29 and 1.26 for curved bridges and straight bridges respectively.[Conclusion]The overturning stability coefficient of single-column pier girder bridges calculated with stochastic analysis model is smaller than that calculated with deterministic analysis model.The deterministic analysis model overestimates the overturning stability of single-column pier girder bridges,because it does not consider the randomness of load effects.The stochastic analysis model treats overturning resistance effects and overturning effects as random variables,enabling more accurate assessment of overturning stability and safety margin of single-column pier girder bridges.
作者
孙士尧
周勇军
王业路
张恒
赵煜
药天运
SUN Shiyao;ZHOU Yongjun;WANG Yelu;ZHANG Heng;ZHAO Yu;YAO Tianyun(School of Highway,Chang’an University,Xi’an,Shaanxi 710064,China;School of Civil Engineering,Qingdao University of Technology,Qingdao,Shandong 266033,China;School of Civil Engineering,Chang’an University,Xi’an,Shaanxi 710061,China)
出处
《公路交通科技》
北大核心
2025年第7期121-132,共12页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(52278138)。
关键词
桥梁工程
汽车荷载模型
目标可靠指标
独柱墩
倾覆
bridge engineering
vehicle load model
target reliability indicator
single-column pier
overturning
