层间状态对沥青路面疲劳开裂与位移的影响

Influence of Interfacial Bond on Fatigue Crack and Displacement of Asphalt Pavement

为了分析沥青路面层间脱开、滑移和疲劳开裂病害的成因,基于弹性层状体系理论,利用BISAR程序和ABAQUS有限元分析软件,分别通过减缩弹簧柔量ALK、Pell疲劳模型表征层间结合状态和路面疲劳性能,研究了有无水平力作用时ALK对沥青路面疲劳寿命、路表位移和层间位移的影响。结果表明:沥青路面疲劳寿命由层间连续转变为非连续时迅速下降,层间光滑状态下的疲劳寿命仅为连续时的1%;有水平力作用时,层间结合状态(连续、半结合、光滑)对路表水平位移影响显著;无论有无水平力作用,层间结合对磨耗层层底的弯拉应变分布有重要影响,且水平力会使路面结构层内的弯拉应力分布的深度增加;水平荷载作用和层间接触不良是自上而下型裂缝(TDC)产生的主要原因之一。

The objective of this paper is to investigate the causes of the interlayer debonding,slippage and fatigue cracking of asphalt pavement.Based on elastic layered system,the BISAR and finite computer program ABAQUS were used,reduced spring compliance（ALK） and Pell＇s fatigue model were included to indicate the interfacial bonding state and predict fatigue life,respectively.The influence of interfacial bond state on fatigue life,surface and interlayer displacement of asphalt pavement were examined.The results showed when interlayer condition turn from full-bond to intermediate or slip,the fatigue life of asphalt pavement decreases sharply,in the case of slip,it is only 1% that of full bond.With horizontal force applied,horizontal displacement at surface was greatly influenced by interlayer bond.Both in cases with or without horizontal force,the tensile strain at the bottom of the wearing course was influenced largely.Besides,the impact depth of tensile strain increased for the existence of horizontal force.The existence of horizontal force and bad interlayer bond condition were in the contributors to the surface initiated cracking.