静态模量和动态模量条件下的沥青路面结构力学性能差异性分析

Difference Analysis of Mechanical Properties of Asphalt Pavement Structures under Static Modulus and Dynamic Modulus

为了获得同一沥青路面结构在沥青混合料取用不同类型模量(静态模量和动态模量)时,路面结构在相同荷载作用下的力学响应规律的差异性,基于柔性基层S1、半刚性基层S2和刚性基层S3沥青路面结构形式计算模型,运用BISAR软件,计算获得了不同计算方案下的沥青路面结构路表弯沉等力学响应量。通过分析可知,在静、动态模量条件下,同种结构对层位功能要求一致。沥青层最大剪应力在静、动态模量条件下的数值相差较小;但路表弯沉、土基顶面压应变和行车方向的拉应变最大值在静态模量下获得的数据较动态模量下获得的数据要大;S1和S2水泥稳定层行车方向最大拉应力静态模量计算结果较动态模量计算结果要小,而S3则正好相反。因此,同一种沥青路面结构,在静、动态弹性模量条件下,结构层的层位功能一致,但各力学计算指标数值存在较大差异。

In order to obtain the difference of mechanical response of the same asphalt pavement structure under the same load when different types of modulus(static modulus and dynamic modulus) are used in asphalt mixture,based on the calculation model of asphalt pavement structure form of flexible base(S1),semi-rigid base(S2) and composite base(S3),by using BISAR software,the mechanical responses such as deflection of asphalt pavement structures under different calculation schemes are obtained by calculation.Through the analysis,it can be seen that the same kind of structure has the same request to the layer function under the static and dynamic moduli conditions.The difference of maximum shear stress between static and dynamic modulus is small.However,the maximum values of road surface deflection,compressive strain on top surface of soil foundation and driving direction tensile strain obtained under static modulus are larger than those obtained under dynamic modulus.The static modulus of the maximum tensile stress of S1 and S2 is smaller than that of the dynamic modulus,while S3 is the opposite.Therefore,for the same asphalt pavement structure,under the static and dynamic elastic modulus conditions,the layer functions of the structural layer are the same,but the values of each mechanical calculation index are quite different.