黄土路基压实标准研究

Research on Compaction Criteria of Loess Subgrade

为从理论上确定黄土路基的压实标准,首先确定以路表弯沉和路基顶面压应变作为受路基压实标准影响的沥青路面设计指标,根据半刚性基层沥青路面力学分析获得的路基内部压应变分布以及在试验路测得的行车荷载作用下路基内部的压应力分布将整个路基分为距路基顶面0-80 cm的路床和路床下路基两部分,通过分析路基回弹模量对于路面结构层厚度的影响确定了路基不同深度处的回弹模量要求,并试验研究了压实度对于压实黄土的回弹模量和浸水后附加压缩变形的影响。最后,结合路基不同压实区域划分、路基回弹模量的要求、压实度对于黄土力学性质的影响提出以回弹模量和压实度双控的黄土路基压实标准。

The object of this paper is to determine the compaction criteria of loess subgrade. The deflection on the surface of the pavement and the compressive strain on the top of the subgrade were considered-to be influenced by the compaction criteria of the subgrade. According to the compressive strain distribution and the compressive stress distribution in the subgrade under the asphalt pavement got from mechanical analysis and field tests respectively, the whole subgrade were divided into two parts. One part is the roadbed which is from zero to eighty centimeters far from the top of the subgrade, the other part is the subgrade under the roadbed. On the basis of the analysis to the influence on the thickness of asphalt pavement of the rebound modulus of the subgrade, the rebound modulus of the subgrade required was determined. The influences of the compactness of the compacted loess on the rebound modulus and collapse property of loess were studied by laboratory tests. On the basis of the results got from the researches above, the compaction criteria including rebound modulus and compactness of the loess subgrade were got.