软土地基上含反射裂缝沥青道路的动力响应分析

假定车辆荷载为正弦均匀分布,软土和复合地基变形行为服从DRUCKER-PRAGER弹塑性屈服准则,基于动力学、线弹性断裂力学和弹塑性力学理论,采用平面应变有限单元法,对含反射裂缝的沥青路面结构进行了分析。为了计算应力强度因子,在裂缝尖端设置了奇异单元。分析过程中,以路表、基层底、软土地基顶最大竖向位移和I型应力强度因子作为表征参量,探讨了车辆单周期动荷载作用下,道路结构的阻尼比、复合地基的回弹模量、粘聚力、内摩擦角和厚度的改变对道路结构工作性状的影响。

Dynamic analysis of asphalt pavement with reflective cracking on the soft clay ground

In the paper, the vehicle load is simplified as sine distributed function,the behaviors of the soft clay ground and the composite foundation obey elastic-plastic yield criterion of DRUCKER-PRAGER model. Based on the theory of dynamic mechanics, linear elastic fracture mechanics and elastic-plasticity mechanics, the asphalt pavement with reflective crack is analyzed under the single cyclic moving load using the FEM of plane strain. In order to compute the stress intensity factor (SIF), singular element is placed near the crack tip. The performances of the pavement are discussed under different material damping ratios of the pavement, the resilient elastic modulus, cohesion, internal friction angle and the thickness of the composite foundation through the maximum displacement in the asphalt pavement surface, the top surface of the composite foundation, the top surface of the soft clay ground and the dynamic SIF in the crack tip.