基于半刚性层模量衰变路面疲劳寿命分析

Analysis of pavement fatigue life based on modulus decay about semi-rigid base

半刚性路面在使用过程中半刚性基层材料的强度是不断衰减的,为正确预估路面的疲劳寿命,以半刚性基层材料模量衰减为切入点,根据层状弹性体系理论,建立路面结构力学模型,分析模量衰减对各路面结构层疲劳寿命的影响,指出我国现行规范设计指标存在的一些问题,提出建议采用沥青面层层底拉应变和半刚性层层底拉应变两项设计指标。同时为避免路面早期破坏,应设法降低半刚性基层层底拉应力水平,提高半刚性材料的抗拉性能。

The strength of semi-rigid base material decays gradually in the course of use.In order to predict the pavement fatigue life correctly,with the modulus decay of the semi-rigid base as the starting point,according to the elastic layered system theory,a mechanical model of pavement structure is established and the influence of fatigue life on pavement layers is analyzed.Then some problems are pointed out about current national criteria and some suggestions are put forward.The design indexes about the tensile strain at the bottom surface of the asphalt surface and semi-rigid base are recommended.In addition,the stress level should be reduced and the tensile performance should be increased in order to avert the pavement damage in the early stage.