加筋沥青路面APA试验及其非线性疲劳损伤分析

APA TEST AND NONLINEAR FATIGUE DAMAGE ANALYSIS OF THE REINFORCED ASPHALT PAVEMENT

应用沥青路面分析仪(APA)对沥青路面结构模拟试件进行多种荷载下的往返轮载疲劳试验,对比研究土工布、玻璃纤维格栅对沥青路面疲劳性能的加筋效果。在此基础上,提出沥青混合料非线性疲劳损伤演化模型,应用基于疲劳损伤力学的非线性有限元方法模拟APA试验过程,分析了试件应力、变形、疲劳寿命等,并与试验结果对比,论证了所提疲劳损伤演化模型的合理性,指出因加筋材料的桥联效应显著地改善了裂缝穿过筋材后路面的受力变形状况,有效地延长路面的疲劳寿命。同时,基于疲劳损伤分析,进一步验证了Paris公式可用于描述路面结构的疲劳裂缝稳定发展过程,并获得了有关的参数。

Wheel repeated loading test is carried out to the asphalt pavement specimen under several loading levels by using Asphalt Pavement Analyzer （APA） to compare the reinforcing effect of fabric and glassgrid on the fatigue characteristics of asphalt pavement. Based on this, one nonlinear fatigue damage model is suggested. By using fatigue damage mechanics-finite element method, the paper simulated numerically the total process of the APA test, and analyzed the stress, displacement and fatigue life of specimens. The comparison between the results of simulation and test proves the rationality of the suggested model. It is pointed out that using reinforcing material can remarkaeblely improve the stress and dispacement levels in pavement after the crack spreads across the reinforcement, and so to increase the pavement＇s fatigue life effectively due to the bridge effect of reinforcing materials. Besides, based on the fatigue analysis, it is proved further that Paris equation can be used to describe the spreading process of the fatigue crack in pavement, and related parameters can be obtained accordingly.