中法高速公路车流及荷载特性对比

Comparison on Highway traffic flow and load properties of China and France

摘要:

选取来自中国和法国的两组利用动态称重设备(weight in motion)实测的高速公路车辆数据进行了统计，对实测车流的车型组成特性、车流时变特性及车辆到达特性，车辆特性，不同车道车流及荷载等特性进行了详细的对比与分析，总结了车流及车辆荷载的一般分布规律。数据显示：国内车重、轴重及交通量等参数都显著高于法国，相对《公路桥涵设计通用规范》（JTG D60-2004）中车辆荷载基础数据也提高很大；每天的交通量在低谷期重车比例最高，而高峰期重车比例最低；各车道之间车流及荷载特性差异性都很大，并不符合互不相关假定；我国实测车辆荷载的效应极值外推结果远大于现行规范值。综合这些特性，建议对特殊桥梁的设计或评估，采用特定地点的车辆荷载；各车道汽车荷载模型应分别考虑；不同加载长度的汽车荷载模型应区别分析。

Abstract:

Two typical highway traffic data measured by WIM equipment in China and France are compared, some statistics and analysis works have been conducted. Traffic flow and load properties are compared in a detail way. The results show that: axle weight, gross vehicle weight and traffic volume of France’s are smaller than that of China’s which indicate an obvious increase comparing with the vehicle data that are used for The current bridge criterion (JTG D60-2004). The constitution of daily traffic show a timely change: trucks have a higher proportion during the low tide, but a lower proportion in peak time.Results can be conclude from those data, that a basic hypothesis of vehicle load model for China design code, which is all vehicle lanes are uncorrelated to each other, may not valid. Both China and France data show traffic flow and load properties in different lanes have obvious differences. Base on those research results, it is recommended at the final that site-specific vehicle model is very necessary for some design and assessment work, and also to improve current design load model, different lanes should be considered to have different model, and a loading length depended load-model should be adapt for diversity span bridge regarding the actual extrapolated effect far outweigh code value.