中文摘要：

为了分析车辆超载运营对公路梁桥疲劳损伤的影响,运用刚性梁法对统计车辆进行轴重分配计算.推导车辆超载率与简支梁桥的疲劳损伤值的关系.运用高斯混合模型（GMM）描述车辆超载运营荷载概率分布,得到车辆超载运营的概率统计模型.在该基础上,结合车辆超载率与简支梁桥疲劳损伤关系式和车辆超载概率模型,提出针对车辆荷载作用下简支梁桥疲劳损伤计算方法.基于WIM系统统计数据对宜泸高速某预应力简支梁桥进行为期一月的疲劳损伤累积计算并对该桥的疲劳寿命进行了评估.分析表明：车辆超载率与简支梁疲劳损伤值程指数函数关系,车辆超载率概率模型呈多峰分布,以宜泸高速某简支梁桥为例,月疲劳损伤值和疲劳寿命分别为5.8×10^-6和88a.

英文摘要：

Vehicle axle weight was calculated by the method of stiffening bar in order to analyze the simple supported bridge＇s fatigue damage under overloading. The equations for overload rate of vehicle and the fa- tigue damage value of simple supported beam were derived. The probability distribution of overloading was described by gaussian mixture model（GMM） . Vehicle overloading rate model was obtained by using the GMM method. On this basis, a new method of calculating the fatigue damage value for simple supported beam was proposed by reference to the relation between overloading rate and fatigue damage. Based on the system of the WIM traffic load statistics data, a prestressed simple supported beam bridge＇s month of fa- tigue damage value was calculated and the fatigue life was assessed in Yilu highway. The results show that there is exponential distribution functional relationship between overloading rate and simple supported beam＇s fatigue damage value. The vehicle overloading probability model presents multi-peak distribution. The damage value and fatigue life of simple supported beam are 5.8×10^-6and 88 years respectively, with simple supported bridge in Yilu highway for example.