戈壁地区不同土质下的路基强度变化规律与数值仿真

Numerical simulation analysis of roadbed strength variation under different soil quality in gobi region

由于回弹模量可以比较好地体现和反映土基本身所具备的一些弹性特点,因此,在道路设计过程中一般都会用回弹模量表示土基强度评估指标。采用室内重复加载三轴试验进行测试,研究分析我国戈壁地区几种典型路基土回弹模量随含水率和围压应力发生变化的规律,再通过二次项回归对含水率与回弹模量的关系进行分析拟合。由结果可知:路基回弹模量受土壤类型、压实度及路基含水率状态影响而发生变化;粉质中液限黏土、低液限粉质土、级配良好砾石土随含水量的增加回弹模量逐渐衰减,密实度的改变对回弹模量的影响并不大;含细粒土的砾石土作为路基土时,应注意在施工时做好地下水防渗,保持路基的湿度与强度。

Because the springback modulus can better reflect and reflect some elastic characteristics of the soil foundation body,the index of soil foundation strength evaluation in the process of road design is generally expressed by the springback modulus.In this paper,indoor repeated loading triaxial test is used to test,and the law of springback modulus of several typical gobi subgrade soil varied with water content and confining pressure stress is studied and analyzed.Then the relationship between water content and springback modulus was analyzed and fitted by quadratic regression.The result shows that the springback modulus of roadbed is affected by soil type,compactness and water content of roadbed.With the increase of water content,the springback modulus of clay with medium liquid limit,silty soil with low liquid limit and well-graded gravel decreases gradually,and the change of compactness has little effect on the springback modulus.When fine gravel is used as subgrade soil,attention should be paid to the anti-seepage work of groundwater during construction to maintain the humidity and strength of subgrade.