沥青面层反射裂缝荷载型应力强度因子回归分析

Regression Analysis of Stress Intensify Factors of Reflective Cracks in Asphalt Pavement under Traffic Load

针对目前对沥青路面的开裂机理研究仅属于定性分析的情况,采用断裂力学理论,通过适当的条件假定,建立了带裂缝的沥青路面结构4层体系平面应变分析模型,对正对称荷载与偏荷载作用下、4种极限层间结合状态所对应的沥青面层反射裂缝张拉型应力强度因子KⅠ与剪切型应力强度因子KII进行了回归和分析。结果表明:在各裂缝扩展比例下,张拉型应力强度因子与剪切型应力强度因子同各结构层参数能够呈很好的幂函数关系,可采用分段回归方法和幂函数乘积的形式对应力强度因子进行回归,给出了回归参数,经过检验,回归精度能够满足实际工程精度要求。

According to the present study of cracked mechanism of asphalt pavement, applying the theory of fracture mechanics and the suitable conditions assumption, the plain-strain model was established to simulate the four-layer asphalt pavement structure with cracks. And then, the corresponding stretching and shearing stress intensify factors of reflective cracks in asphalt pavement of four limited interlaminar combinations were regressed and analyzed under symmetry and bias load. The result shows that the stretching and sheafing stress intensify factors are in power function relation with the each layer parameters in every propagation ratio of fracture. Therefore, applying the segmented integral method and power function form, the applicable regression formulas were given.By test, the regression precision can satisfy the actual engineering.