某八车道高速公路车流特性及荷载效应

Vehicle Flow Characteristics and Load Effect of A Eight-lane Highway

以某高速公路扩建前后的实测车辆荷载数据为基础,对不同车道车流的分布及荷载组成进行了统计,归纳车流及荷载的空间分布规律,并据此探讨沥青路面及桥梁结构对车流横向差异的敏感性.结果表明,车辆的车道选择差异显著,70%以上的二轴车倾向于在内侧两个车道行驶,90%以上的多轴车选择在外侧两个车道行驶;内侧车道交通分布密集,但是车辆荷载水平较低,外侧车道车辆荷载水平远在内侧车道之上;车辆荷载下十年内超车道路面仍然满足使用性能要求,而其余各车道路面损坏程度很大,必须进行维护;单向四车道桥梁行车道2上车辆荷载弯矩效应极值远大于其他车道,在不同加载长度下,各车道实测效应极值基本大于规范值,说明目前规范车辆荷载模型已无法满足实际的结构设计评估要求,建议修正.

Weight in motion （WIM） system is adopted to obtain actual traffic data of a four-lane highway and a two-lane highway （in one direction） in Guangdong Province, China. Vehicle distributions and load composition on different lanes are analyzed statistically, and spatial distribution laws of vehicle flow and load are explored. Based on the analysis, sensitivity of the asphalt pavement and bridge structure to the transverse differences of vehicle flow is discussed. Results indicated that there exists huge variation for vehicle lane- choice feature. Over 70% vehicles with two axles prefer to run in the inner two lanes, and over 90% vehicles with more axles incline to travel in the outer two lanes. Traffic distribution for the inner lanes is highly concentrated, but the vehicle load level for which is relatively low; The vehicle load level for the outer lanes is far above which for the inner lanes. The pavement for the passing lane is still of good performance under the action of the vehicle load in ten years, meanwhile the pavement for the other lanes is badly damaged and demands maintenance. The maximum moment effect extreme value caused by vehicle load appears in the driving 2. For different loading lengths, the measured effect extreme values basically exceed the corresponding code values, which shows that the vehicle load model of current Chinese code cannot meet the actual demand of structural design and assessment,and need proper revision.