路面结构层温度特征值的估计

基于宁波、大同、广州三地的路面结构温度测站及江苏镇凓高速公路、山东济莱高速公路的现场温度测站超过1年的路面温度数据,从研究路面结构温度日较差、日平均温度和温度正较差之比的基本特征和相互关系着手总结了它们随路面深度的衰减规律并给出了回归式,通过引入"广义"深度坐标z/槡α(z为距离路表深度,α为材料导温系数)消除了路面材料不同引起的差异,提出了用路表温度特征值估计路面结构层任一深度日温度特征值的方法和公式,并推广至任一深度日温度特征值已知的场合,最后利用LTPP(LongTerm Pavement Performance)项目中01-0101(State code-SHRP ID)试验段的数据对模型进行验证.结果表明:本文提出方法和公式在估计路面结构不同深度的日最高温度、日最低温度时具有良好精度,其偏差的均方值不超过2.0℃,偏差的平均值小于0.6℃,可满足工程要求.

Estimation of Characteristic Temperatures in Pavement Structure

Based on measured data of temperatures in asphalt and concrete pavements placed at meteorological observation stations in Guangzhou,Ningbo and Datong cities as well as those in pavements at Zhenli and Jilai expressway jobsites over 1 year,the basic features and relationship among pavement diurnal temperature variation,diurnal average temperature and the ratio of positive temperature variations were studied,and the rules of variables mentioned above versus the pavement depth were summarized,and corresponding regressed formulas were provided;a generalized depth z/α(α is the material thermal diffusivity coefficient)was introduced to eliminate the discrepancies caused by pavement materials,thus the methods and formulas by using characteristic temperatures on road surface to estimate diurnal temperature variation in pavements at any depth were issued,furthermore,the formulas were extended to circumstances of given diurnal temperature variation in pavements at arbitrary depth,and the model’s accuracy was verified by measured data in the 01-0101 section of long-term pavement performance(LTPP) program in USA.The results show that the methods and formulas proposed hereof are accurate enough to estimate the diurnal maximum and minimum temperatures in pavements at any depth,the standard deviations arising out of the formulas are not greater than 2.0 ℃,and the averages of standard deviations are less than 0.6 ℃,however,the formulas can meet the requirements of engineering practice.