隧道半刚性基层沥青路面沥青层疲劳开裂分析

Analysis of fatigue cracking of asphalt layer of tunnel semi-rigid base asphalt pavement

为了研究隧道半刚性基层沥青路面沥青层疲劳开裂的影响因素,建立隧道半刚性基层沥青路面有限元模型,对隧道半刚性基层沥青路面沥青层疲劳开裂进行研究。研究结果表明:对于隧道半刚性基层沥青路面,由于沥青层内最大拉应变显著大于沥青层底拉应变,导致沥青层内的疲劳寿命远小于沥青层底的疲劳寿命;沥青层层底疲劳开裂寿命影响因素敏感性排序为:基层模量>面层模量≈面层厚度>基层厚度;隧道半刚性基层沥青路面基层模量越大、基层厚度越厚、沥青面层模量越小,对沥青面层疲劳开裂寿命越有利。

In order to study influencing factors of fatigue cracking of the asphalt layer of tunnel semi-rigid base asphalt pavement,the fatigue cracking of the asphalt layer was researched by establishing a finite element model of tunnel semi-rigid base asphalt pavement.The results show that maximum tensile strain of the asphalt pavement inside is significantly bigger than that of the asphalt pavement bottom,which causes that fatigue life of the asphalt pavement inside is far shorter than that of the asphalt pavement bottom.The sensitivity of influencing factors of fatigue cracking life of the asphalt layer bottom is ranked as follows:the modulus of the base layer>the modulus of the surface layer≈the thickness of the surface layer>the thickness of the base layer.The larger the base layer modulus is,the thicker the base layer thickness is and the smaller the asphalt surface layer modulus is,the more favorable for the fatigue cracking life of the asphalt layer it is.