级配碎石基层非线性对沥青路面结构受力的影响

Effect of Nonlinearity of the Graded Crushed Stone Base on Mechanical Behaviors of Asphalt Pavement Structure

目的基于级配碎石基层材料的非线性特征，研究级配碎石上基层沥青路面结构力学响应规律，进而为该种路面结构设计提供理论依据．方法通过ABAQUS有限元软件的二次开发，运用Fortran语言对级配碎石非线性本构模型进行编译，建立级配碎石上基层沥青路面结构的有限元模型．结果随级配碎石层和面层厚度的增加，级配碎石非线性沥青路面结构各结构层所受层底拉应力较级配碎石线弹性沥青路面结构都有所增加，路表弯沉变化不大．推荐在中等级交通下的面层厚度为7—15cm，级配碎石层厚度为10—15cm．结论应用该种路面结构时，考虑到级配碎石层非线性对该路面结构受力产生的不利影响，必须确定合理的级配碎石层和面层厚度．

The purpose of this paper is to study mechanical behavior of asphalt pavement structure with the upper base of the graded crushed stone, taking nonlinearity of the graded crushed stone material into consid- eration and to provide theoretical references for pavement structure design. Based on the secondary develop- ment of ABQUS, the nonlinear constitutive finite element model of the asphalt pavement structure with gra- ded crushed transition layer is built. The computation results using Fortran language show that, as the thick- ness of upper layer and surface layer increases, the bottom layer tensile stress in the asphalt pavement struc- ture with non-linear graded crushed stone is greater than that in the asphalt pavement structure with linear graded crushed stone. But their surface deflections are little changed. It is noted that, considering the unfavor- able effect of nonlinearity of graded crushed stone base on pavement structure, thickness of graded crushed stone layer and surface layer must be selected reasonably, if this pavement structure is used. For the middling level of road traffic,it is proposed that the surface thickness 7 ~ 15 cm and the graded crushed stone layer thickness 10 - 15 cm should be used.