高纬度多年冻土区路面类型对路基热稳定性影响分析

基于附面层理论,引入焓值建立伴有相变的二维非稳态温度场数值模型,分别对水泥混凝土和沥青两种路面下路基温度场的变化规律进行分析。研究结果表明,水泥混凝土路面下路基温度场明显低于沥青路面,不同深度处路基的温度场变化存在一定的滞后性,随深度的增加路基内温度场比路基基底以下的温度场变化幅度大;路表温度明显低于路基的内部温度,并在路基内部形成融土核;水泥混凝土路面融化深度小于沥青路面,融化速率趋于平稳,因此,在多年冻土区采用水泥混凝土路面比较有利。

Influence analysisof pavement types on thermal stability of subgrade in high-latitude permafrost area

On the basis of boundary layer theory,the enthalpy value is introduced to establish a twodimensional unsteady temperature field numerical model with phase transition,and the variation law of subgrade temperature field under cement concrete and asphalt pavement is analyzed.The result shows that the temperature field of subgrade under cement concrete pavement is significantly lower than that under asphalt pavement,and the variation of subgrade temperature field at different depths has certain hysteresis,and the temperaturefield change amplitude of subgrade with the increase of depth is larger than that under subgrade base.The pavement temperature is obviously lower than the temperature of subgrade,and the subgrade is formed with melting soil core.The melting depth of cement concrete pavement is lower than that of asphalt pavement,and the melting rate leveled off.It is advantageous to adopt cement concrete pavement in permafrost area.