水分迁移引起千枚岩填筑路基回弹模量衰变对路面结构力学特性的影响

Effects of Resilience Modulus Decay of Phyllite Packing Embankment Caused by Water Migration on the Mechanical Properties of Pavement Structure

为了分析水分迁移对千枚岩填筑路基回弹模量及其对路面结构力学特性的影响规律,基于水分补给条件下千枚岩填料回弹模量测试的试验结果,应用数值建模并分析了一般路基和路侧积水路基千枚岩填料路面结构层的力学特性,及路面结构层水平应力、轴向应力以及最大主应变的变化规律。结果表明:在试件底部补水条件下,各层含水率逐渐增大;随着深度的增加含水率呈现减小趋势;水分迁移引起土基回弹变形量逐渐增大,回弹模量大幅度降低,衰变率为60%;各路面结构层的方向应力及最大主应变随着回弹模量衰减率的改变产生较大变化,表现为边坡发生侧移和路面结构层容易发生不均匀沉降,进而形成纵向裂缝;基层是整个路面结构层的薄弱层,容易在过大拉应力作用下发生开裂,最终反射到面层并导致其出现反射裂缝,严重影响了道路整体的使用寿命。

In order to analyze the influence of water migration on the rebound modulus of phyllite packing embankment and its influence on the mechanical properties of pavement structure,the experimental results of the modulus test of phyllite packing under the condition of water replenishment were applied to numerical modeling and analysis. The mechanical properties of the basalt-filled pavement structural layer of the roadbed and roadside watersoil subgrade,and the horizontal,axial and maximum principal strains of the pavement structure were obtained.The results show that under the condition of water replenishment at the bottom of the specimen,the water content of each layer gradually increases. With the increase of depth,the water content shows a decreasing trend. The migration of soil foundation causes the rebound deformation of soil foundation to increase gradually,the modulus of resilience is greatly reduced,and the decay rate is 60%. The directional stress and the maximum principal strain of each pavement structure layer change with the change of the modulus of resilience modulus. The large change is manifested by the side shift of the slope and the uneven formation of the pavement structure layer,which leads to the formation of longitudinal cracks. The base layer is the weak layer of the entire pavement structure layer,which is easy to crack under the excessive tensile stress,and finally reflects to the surface layer and causes the reflection crack to appear,which seriously affects the service life of the whole road.