中文摘要：

将不同车辆组成的车队等效成均布荷载,假定车辆匀速行驶于桥梁上,采用卷积公式计算不同车辆连续到达间距及总重的概率密度函数,应用平衡更新过程理论推导车队长度概率函数,依据中国现有车辆荷载统计数据,建立了既有公路桥梁车辆荷载效应模型。该模型通过截尾分布限定其中各参数的最大值、最小值来反映不同交通类型,通过影响线传递函数反映不同桥梁结构形式。研究结果表明：车辆间距、车长、车重及车速的分布是决定车辆荷载效应模型的关键;该模型适用于既有公路桥梁时变可靠性和剩余寿命评估。

英文摘要：

The motorcade consisted of various vehicles was equivalent to the uniform load. The vehicles were assumed to run in uniform velocity on the bridge. The probability density functions of total weight and spacing intervals for various continuous arrivals of vehicle were computed by the convolution formula. The equilibrium renewal process was used to deduce the probability density function of the motorcade length. Based on the existing vehicle load statistic data in China, the vehicle load effect model for the existing highway bridge was established. The traffic types were reflected by restricting the maximum and minimum values of some parameters based on the truncated distribution in this model. The bridge types were considered by the influence line transfer function. The study result shows that the distributions of vehicle length, spacing interval, vehicle gross weight, and vehicle velocity determine vehicle load effect. This model is suitable for the time variant reliability and remaining life evaluation on the existing highway bridges.