温度场及非均布移动荷载作用下

Dynamic Response Analysis of Asphalt Pavement Due to Combined NonUniform Moving Load

摘要:

为研究路面结构实际温度场对沥青路面结构动力响应的影响，基于路面结构温度场现场实测数据及室内实际路面材料动态模量试验结果，建立温度场分析和非均布移动荷载作用下沥青路面瞬态动力分析三维有限元模型，分析路面结构在实际温度荷载作用下的动力响应规律，并与传统的等温结构模型动力响应结果进行对比分析.结果表明，层底控温方法模拟出的温度场可用于分析夏季高温时段和低温时段沥青路面的实际动力响应；夏季一天中高温时段，等温模型高估了竖向应变及上、下面层的剪应变，低估了中面层的剪应变；夏季一天中低温时段，沥青路面的实际动力响应大于等温模型的计算值，等温模型低估了温度分布对沥青路面车辙和开裂的影响.

关键词:道路工程; 等温模型; 数值模拟; 动力响应; 温度场; 非均布移动荷载

Abstract:

To study the influence of temperature distribution on the dynamic response of asphalt pavement, a 3D finite element model in transient mode of asphalt pavement, subjected to nonuniform moving load, was established based on the measured temperature distribution in the field and the dynamic modulus results of the actual pavement material in lab. The dynamic response time history and spatial distribution of pavement structure within the actual temperature field was analyzed and compared with that of the isothermal structure model. The result shows that the temperature simulated by the bottom temperature control method could be used to analyze the actual dynamic response during both the lowtemperature and hightemperature period in summer. The isothermal pavement structure overestimates the vertical strain and the shear strain of upper layer and lower layer, but underestimates the shear strain of the middle layer during the hightemperature period in summer. During the lowtemperature period in summer, the actual dynamic response of asphalt pavement was larger than the value calculated from the isothermal model. The isothermal model underestimates the effect of temperature distribution on the rutting and cracking potential of asphalt pavement.

Key words:road engineering; isothermal model; numerical simulation; dynamic response; temperature field; nonuniform moving load