Abstract: The thesis analyses the stress characteristics of reflection crack on the most unfavorable place of the load through the finite element modeling for asphalt overlay on old cement concrete pavement by ANSYS software and the diversification of the stress intensity factor K in the light of fracture mechanics. The calculation results indicate that the slip affected stress intensity factors KI and KII governing pavement crack propagation trend to decrease with the thickness increase of asphalt overlay under traffic loading and temperature. The stress intensity factor on the crack tip increases with the modulus increase of asphalt overlay. Furthermore，the crack resistance is affected by temperature drop range and axle load difference.

Key words: asphalt overlay, reflection crack, fracture mechanics, stress intensity factor

摘要： 通过建立旧水泥混凝土路面沥青加铺层有限元模型，应用ANSYS软件计算分析了车轮荷载位于最不利位置 时反射裂缝的受力特性，并根据断裂力学理论研究了在不同影响因素下应力强度因子K的变化。计算结果表明: 在荷载和温度作用下，控制着路面裂缝扩展的应力强度因子KⅠ 和KⅡ 随着沥青加铺层厚度的增加呈减小趋势;同 时，裂缝尖端的应力强度因子将随着沥青加铺层模量的增加而增大;此外，降温幅度和轴载的变化对加铺层抗裂性 能也有较大影响。

关键词: 沥青加铺层, 反射裂缝, 断裂力学, 应力强度因子