基于路基动应力的路基工作区深度确定方法研究

Study on the Method of Determine Roadbed Work Area Based on the Dynamic Stress

鉴于考虑路面厚度和材料刚度影响的 J．Boussinesg修正公式所得的路基工作区深度过小，仅至上路床部位，与实际情况不符。提出了基于竖向路基动应力分布规律确定路基工作区深度的方法。通过比较模型试验和计算模拟在竖向动应力和动位移沿深度方向的衰变规律，发现衰变规律在路基工作区深度范围符合性较好，验证了该方法的正确性与可靠性。对典型结构组合下路基动应力与工作区深度进行计算分析，分析结果表明：在标准汽车荷载100、130 kN 作用下，路基顶面动应力为6．4～13．4 kPa，相应的工作区深度为0．6～0．9 m。在重交通和特重交通的汽车荷载170 kN、200 kN 作用下，路床顶面动应力为12～20．6 kPa，相应的工作区深度为1．0～1.2 m，已进入上路堤范围0．2～0．4 m。

In view of the fact that the depth of roadbed work area obtained by J.Boussinesg modi-fied formula which take the effect of pavement thickness and material stiffness into consideration is too small,only to parts of the road bed.The result does not match the actual situation.In this study,the method which used the vertical roadbed dynamic stress distribution law to determine the depth of the roadbed work area was proposed.A consistency of the vertical dynamic stress and displacement decay law along the depth direction between the model test results and the simulation data shows the method devel-oped is accurate and credible.The paper analyzed the roadbed dynamic stress and the depth of roadbed work area in typical structure combination conditions.The results show that the dynamic stress on top of roadbed is 6.4 ~13.4 kPa and the depth of work area corresponding to 0.6 ~0.9 m under the standard traffic load 100、130 kN.The dynamic stress on top of roadbed is 12 ~20.6 kPa and the depth of work area corresponding to 1 .0 ~1 .2 m,has entered the range of embankments 0.2 ~0.4 m,under the heavy traffic and special heavy traffic load 170 kN、200 kN.