行车荷载作用下路基动态竖向应力测试研究

为了研究交通荷载对高速公路路基的影响，在不同交通荷载、车速及车型的情形下，对谷竹高速公路27标段路基进行了动态竖向应力测试。结果表明:在荷载作用下，路基竖向应力随深度增大而逐渐衰减，且在路基浅层衰减较慢，然后加速，达到一定深度后，再次变缓。随着交通荷载增加，路基工作深度及竖向应力也会随着增大，但荷载增到较大后，工作深度的增幅会降低。在相同交通荷载情形下，路基浅层竖向应力会随着行车速度增大而减小，但车速变化对路基的工作深度影响较小。车型对路基的影响与理论相符，增加后轴轮胎数目可以减小交通荷载对路基的影响。

Research on Dynamic Vertical Stress of Subgrade under Vehicle Load

For analyzing effect on highway subgrade by vehicle load, experiment of dynamic vertical stress was carried out on the subgrade of 27 section of Guzhu highway in case of different loads, velocities and types of freight vehicle. According to the analysis about testing results, some valuable conclusions were obtained. Under load effect, vertical stress value of subgrade is gradually attenuated with increase of the subgrade depth and the attenuation is slow in shallow layer of the subgrade and then speeds up and slows again while reaching a certain depth. The work depth and vertical stress value is also increased with the increase of vehicle load. However, the work depth will increase slowly when the load is increased largely. On the condition of the same vehicle load, the vertical stress value in shallow layer of subgrade decreases with increase of the freight vehicle speed, but speed change has a little effect on the work-depth of subgrade. The effect of vehicle type on the subgrade is consistent with the theory and increasing the number of rear axle tires can reduce the impact of vehicle load on the subgrade.