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基于半刚性基层沥青路面反射裂缝严重性，应用断裂力学理论及有限元软件ABAQUS，建立20结点等参有限元模型，数值模拟沥青路面反射裂缝的扩展，并应用Paris公式预估其疲劳扩展寿命，分析探讨反射裂缝扩展过程中应力强度因子K2 的变化规律及路面结构参数对其扩展寿命的影响.计算表明：(1)沥青面层反射裂缝的扩展只考虑偏荷载作用，K2 随着裂缝的扩展不断增大，初期扩展速度较慢，后期扩展速度急剧增加，直至破坏.(2)路面结构参数中，面层厚度、基层模量、底基层厚度、底基层模量和土基模量的增加对面层反射裂缝疲劳扩展寿命有利，而面层模量和基层厚度的增加则不利于面层反射裂缝的疲劳扩展.

Reflective Crack Propagation and Fatigue Life of Semi-Rigid Base Asphalt Pavement

For the severity of semi-rigid base asphalt pavement reflective crack,a finite element analysis model of 20-node isoparametric elements is established by the FEM software ABAQUS and fracture mechanics theory.The reflective crack of pavement is numerically analyzed and the crack fatigue propagation life is evaluated by the Paris formula.In the course of reflective crack propagation,the change of the stress intensity factor(K2) is discussed and the effect of pavement parameters on reflective crack fatigue propagation life is studied.The results indicate:(1) the propagation of reflective crack is dominated by deflection load.In the course of crack propagation,K2 keeps increasing till to damage.(2) The reflective crack fatigue propagation life increases with the raises of the surface course thickness,the base modulus,the subbase thickness and modulus and the subgrade modulus.It decreases with the increase of the surface modulus and the base thickness.