Abstract: The regression mathematical model of tensile stress in the middle layer of the three-layer flexible pavement is basedon the analysis of elastic multilayer thery. he new regression formula of tensile stress in the middle layer of convention-al three-layer pavement is obtained by regression theory. A number of results of regression frmula show good accuracyfor engineering application.

Key words: elastic properties, flexible pavement, tensile stress, regression analysis

摘要： 在分析了三层连续体系中层弯拉应力的解析解及常见路面结构厚度和模量范围的基础上，改进了文献[2]提出的简式公式，提出了一个计算三层连续体系中层弯拉应力的统一公式，并扩大了公式的使用范围；精度分析表明，回归公式的精度明显优于现行的查图法，与解析解相比误差也很小。

关键词: 弹性性质, 柔性路面, 弯拉应力, 回归分析