基于直接概率积分法的预应力混凝土斜拉桥体系可靠性分析  

System Reliability Analysis of Prestressed Concrete Cable-stayed Bridges Based on the Direct Probability Integral Method

作　　者：黎丙柱 LI Bingzhu

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114

出　　处：《重庆建筑》2025年第1期52-56,共5页Chongqing Architecture

摘　　要：斜拉桥体系可靠性分析是斜拉桥结构安全分析的重要组成部分。提出基于直接概率积分法分析预应力混凝土斜拉桥整体动态可靠度的方法:首先,建立斜拉桥主梁抗弯强度失效、风致振动失效、主塔顺桥向强度破坏失效和横桥向屈曲失效以及拉索的强度破坏失效的极限状态方程;然后对全桥拉索进行可靠性分析,选择最危险的3对拉索与斜拉桥的主梁、索塔失效模式组成串并联体系,建立多个功能函数的极值映射的联合概率密度积分方程;最后使用含Heaviside函数的直接概率积分法(DPIM-H)对方程进行求解,得到斜拉桥整体动态可靠度指标,并用蒙特卡洛方法验证结果的合理性。以预应力混凝土斜拉桥为例,用DPIM-H分析了其体系度,同时用蒙特卡洛法对计算结果进行验证。System reliability analysis of cable-stayed bridges is a crucial component of structural safety assessments for such bridges.This study proposes a method for analyzing the overall dynamic reliability of prestressed concrete cable-stayed bridges based on the direct probability integral method(DPIM).First,limit state equations are established for the bending strength failure of the main girder,wind-induced vibration failure,longitudinal strength failure of the main tower,transverse buckling failure,and strength failure of the cables.Next,the reliability of all the cables in the bridge is analyzed,and the three most critical cable pairs are selected to form a series-parallel system with the failure modes of the main girder and pylon.A joint probability density integral equation is constructed for the extreme mapping of multiple performance functions.Finally,the direct probability integral method with Heaviside function(DPIM-H)is applied to solve the equation and obtain the overall dynamic reliability index of the cable-stayed bridge,with the results validated using the Monte Carlo method.Using a prestressed concrete cable-stayed bridge as an example,the system reliability is analyzed with DPIM-H,and the results are verified using the Monte Carlo method.

关 键 词：斜拉桥 体系可靠性 直接概率积分法 蒙特卡洛法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]