Abstract: To analyze the deflection basin curve characteristics of semi-rigid base asphalt pavement under FWD load, a dynamic finite element model was established. By changing the modulus and thickness of the structural layer, the influence of geometric parameter index and strength change of each structural layer on the curve of deflection basin was analyzed. The results show that the area index A3 can better evaluate the overall strength of the pavement. When the modulus ratio E1/E2 is greater than 0.5, d0/d1 is only related to the surface modulus value. The cubic-polynomial fitting curve of the deflection basin and the radius of curvature at a distance of 0.15 m from the load center have a highly linear correlation with the modulus of surface layer and base layer. The effect of the surface layer modulus is mainly in the range of C1~C2, and the effect of the base layer modulus is mainly manifested at d8. Controlling the change of single variable (modulus), the strength of pavement structure is the most sensitive to the change of subgrade modulus; controlling the change of single variable (thickness), the strength of pavement structure is the most sensitive to the change of subgrade thickness.

Key words: road engineering, finite element, semi-rigid base asphalt pavement, deflection basin, geometric characteristics, structural strength

摘要： 为研究FWD载荷作用下半刚性基层沥青路面的弯沉盆曲线特性，建立了动力有限元模型，通过改变结构层的模量和厚度，分析了弯沉盆几何参数指标以及各结构层强度变化对弯沉盆曲线的影响。研究表明：面积指标A3能够更好的评价路面整体强度；当模量比E1/E2＞0.5时，d0/d1仅与面层模量值大小有关；三次多项式拟合弯沉盆曲线，距离荷载中心0.15 m处的曲率半径与面层和基层模量存在高度线性相关关系；面层模量作用效果主要表现在C1~C2范围内，土基模量作用效果主要表现在d8处；控制单一变量(模量)变化，路面结构强度对土基模量变化最为敏感，控制单一变量(厚度)变化，路面结构强度对基层厚度变化最为敏感。

关键词: 道路工程, 有限元, 半刚性基层沥青路面, 弯沉盆, 几何特性, 结构强度