根据广州某高速公路设置的车辆动态测重系统获取的车辆荷载信息，包括所在车道、 车型( 车轴数) 、轴重、总重、车速和通过时刻等数据，对车流中车辆间距的时变特征进行了分析; 根据分析结果，就实际车流荷载对桥梁结构的作用进行了简化; 通过引入荷载横向分布的概念，将车辆随机载荷从二维问题转化为一维问题，由此模拟得到了桥梁跨中弯矩的应力- 时间历程．利用该历程数据，提出了一种公路桥梁随机载荷谱的模拟和编制方法，并得到了可用于疲劳实验的随机载荷谱( 实验谱) ．与现有的公路桥梁车辆载荷谱的模拟和编制方法相比，采用文中方法所模拟和编制的随机载荷谱更接近桥梁的实际工作状态．

According to the vehicle loading data collected by the weigh- in- motion system installed on a certain sec-tion of a highway in Guangzhou,including the lane,the motorcycle type,the axle load,the total weight,the velo-city and the vehicle transit time,the time- varying characteristics of vehicle spacing in vehicle flow are analyzed.Then,according to the analysis results,the effect of vehicle load on the bridge is simplified,and,by introducingthe concept of transverse load distribution,the 2D problem of random vehicle load is converted into a 1D one,which helps successfully obtain the stress- time process of the mid- span bending moment of the bridge.By using thestress- time data,a simulation method to obtain the random load spectrum of a highway bridge is proposed,and arandom load spectrum for random fatigue tests (experimental spectrum) is finally compiled.As compared with theexisting simulation method,the proposed method is more effective because it helps to simulate and compile the ran-dom load spectrum that accords better with the actual working conditions of the bridge.