基于季节时温的沥青路面温荷耦合动力性能分析

Dynamic Performance Analysis of Asphalt Pavement Under Moving Vehicle Load and Seasonal Temperature Variation

为探究大温差地区季节时温变化对沥青路面性能的影响规律,考虑沥青混凝土的时温粘弹性,采用数值模拟方法,针对两种典型沥青路面结构——水泥稳定碎石半刚性基层(结构S1)及级配碎石柔性基层(结构S2)进行了基于季节时温变化的路面结构温荷耦合动力行为与性能分析.结果表明:随轴重增加、动载频率降低、水平推力方向由与行车方向相反变为与行车方向相同以及层间状态恶化,沥青层层底应力总体呈增大趋势,疲劳寿命逐渐降低;路面温度分布的变化对各结构层拉应力的影响表现为夏季显著而冬季不显著,且对于面层层底拉应力,夏季小于冬季,高温时刻小于低温时刻,基层拉应力则表现出相反的变化趋势;虽然结构S1的沥青层在不同时温下的疲劳寿命优于结构S2,但存在随时温改变而急剧波动的不足;相反,结构S2波动小,性能稳定,具有更好的环境适应性.

In order to reveal the effect of seasonal temperature variation in the areas with large temperature differ-ence on the performance of asphalt pavement, this paper takes into consideration the time-temperature viscoelastici-ty of asphalt concrete, and performs numerical simulations to analyze the dynamic behavior and performance under moving vehicle load and seasonal temperature variation for two kinds of typical asphalt pavement structures. One is the structure with a semi-rigid base layer containing cement-stabilized macadam （ structure S I） and the other with a flexible base layer containing graded aggregate materials （ structure S2 ） . The results show that （ 1 ） with the in-crease of axle load, the decrease of dynamic load frequency, the change of horizontal thrust direction from the oppo-site to the same direction of the moving vehicle, or with the deterioration of interlayer conditions, the stress at the bottom of the asphalt layer generally increases, while the fatigue life gradually decreases; （ 2 ） the variation of pave-ment temperature distribution significantly influences the tensile stress of each structural layer in summer but slightly influences the stress in winter; （3） at the bottom of the surface layer, the tensile stress in summer or at high tem-perature is less than that in winter or at low temperature, while the base layer shows an opposite trend in this re-gard ;and （4） although the fatigue lifetime of the asphalt layer of structure SI under various age and temperature conditions is longer than that of structure S2, it has a deficiency of drastic fluctuation, while S2 has a relative stable fatigue behavior and a superior environmental adaptability.