中文摘要：

采用微观交通流模型中的元胞自动机模型（CA模型）,建立了大跨桥梁多车道随机车流数学模型,编制了可视化的车流模拟程序,用元胞的演变模拟大桥上车流的运行状态。以南京长江二桥为例,通过分析实测车流数据确定了车流模型中各个车道的车型比例及车辆的断面发车率等交通特征参数。对来自二桥收费站的数据进行分析,得到不同车型车质量的分布函数及参数。把这些参数输入程序模拟得到二桥上车辆时空分布情况及每个时刻对应的车质量、车速等数据。通过模拟数据与实测值的对比,发现模拟车流结果与实际车流情况较吻合,从而验证了该模拟方法的有效性。该方法的实现为随机车流荷载的生成及桥梁动力响应分析提供了一种有益的模式。

英文摘要：

A mathematical model of multi-lane random traffic flow was presented based on the cellular automata model（ CA model） of microscopic traffic flow.The visual random traffic flow simulation program was developed to simulate the variation of the traffic condition on the bridge with the evolution of cells.Taking the case of the Second Yangtze River Bridge of Nanjing as an example,the proportion of vehicle type and vehicle average arrival rate of each lane were determined according to the tested traffic flow data of the bridge.The distribution pattern and parameters of different vehicle type and weight were ascertained by analyzing the data from the toll station. By inputting these parameters into a program,the space distribution of vehicles in the Second Yangtze River Bridge of Nanjing and the weight,speed of corresponding vehicles were obtained. It shows that the simulative traffic flow basically corresponds well with actual situation according to the comparison between simulative and measured data. The results validate the accuracy of the simulation method. Therefor,the implementation of the method can provide the support for the generation of random traffic flow load and the realization of bridge dynamic analysis.