隧道洞口路面两种材料交替对行车的影响及交替位置优化

用动力学仿真手段模拟了直隧道和曲线隧道洞口路面两种材料交替区域的行车过程,获得了路面材料交替位置前后的行车动力学响应。分析了车辆加速度、制动强度、路面材料交替位置和附着系数差异等因素对行车的影响。结果表明:两种路面材料交替位置的附着系数突变是洞口事故最主要的致因,而其机理是左右轮载不相等导致车辆在驶经交替位置时发生横摆。制动行为对曲线隧道洞口行车稳定性的影响要比直隧道洞口显著,而加速行为对行车的影响更为明显。两种材料交替的位置对行车稳定性影响较大,设计时在隧道入口应将沥青路面延伸至车辆制动结束之后,出口的交替位置应安排在车辆加速起点之前。为了减小附着系数差异,应保证洞内水泥路面的附着系数在0.35之上。

Effect of road pavement material change at tunnel entrance and exit on vehicle operation and optimization of transition location

The vehicle operations on the entrance and exit transition road section of the straight or curved tunnel were simulated by dynamics simulation means. The dynamic responces of the vehicle before and after the road pavement change were obtained. The effects of the vehicle acceleration, the braking intensity, the pavement material transition location, and the adhesion coefficient change on the vehicle operation were analyzed. The simulation results showed that the abrupt change of the adhesion coefficient at the pavement material transition is the primary contributory factor to vehicle accident a tunnel entrance and exit due to the yaw of the vehicle driving through the parement transition from the uneven trie loads on the left and right sides. The effect of the braking behavior on the vehicle driving stability at the entrance and exit of a curved tunnel is more significant than that of a straight tunnel, and the acceleration behavior shows even a more obvious effect. The transition location has a large effect on the vehicle driving stability. The tunnel design showed extend the road asphalt pavement at the entrance section to the location where the braking of vehicle has ended , and locate the exit transition before the vehicle starts acceleration. The adhesion coefficient of the concrete pavement inside the tunnel should be above 0. 35 to avoid excessive difference of the adhesion coefficient.