考虑层间状态的沥青路面温度与荷载耦合行为分析

Simulation of the temperature and load coupling effect on asphalt pavement considering inter-layer conditions

沥青路面是典型的层状体系,层间黏结状态的好差直接影响到路面的使用性能。采用三维非线性有限元软件ABAOUS,同时考虑沥青混合料的劲度模量随温度变化的特性,数值模拟计算了沥青路面在不同温度场状况下分别与水平及竖向荷载耦合作用的关键力学响应,分析各响应指标随层间接触状态变化的特性。研究结果表明:由于接触模型作用机理的不同,其关键力学指标响应要比连续模型下的大;除路表竖向变形大小几乎与层间接触状态无关外,其他指标在低温状况下,层间接触条件变化对其影响较小,而在高温状况下,特别当层间接触摩擦系数μ<0.6时影响很大,尤其对基层、底基层的最大拉应力及面层的最大剪应力影响显著。研究成果为科学解释沥青路面在不同环境温度与车辆荷载综合作用下的破损特征与行为机理提供了有力依据,为改善层间黏结条件有利于提高路面整体性能提供了理论支撑。

Inter-layer condition plays an important role for the structural response and field performance of asphalt pavement due to its typical layered structure. The critical structural response of asphalt pavements under the coupled application of environmental and axle load were simulated. ABAQUS was used to conduct a three dimensional nonlinear analysis to compare the influences of layer conditions on pavement responses. The results show that the critical responses with a contact model are greater than those with a continuous model, and that the maximal tensile stress in the base and sub-base layers and the maximal shear stress in the surface layer are significantly influenced by layer condition, and more specifically, when the coefficient of friction is less than 0.6 with presence of high temperature, only the surface deflection of the asphalt layer is not greatly influenced by layer condition. The findings may explain the performance mechanism of the asphalt pavements in China and provide a theoretical support for improving layer condition in design and construction phases to ensure the structural integrity of asphalt pavements.