沥青路面Top-Down裂缝的断裂力学分析  

Analysis of Top-Down Cracking of Asphalt Pavements Based on Fracture Mechanics Approach

作　　者：赵延庆[1] 王抒红[1] 周长红[1] 谭忆秋[2] 

机构地区：[1]大连理工大学交通运输学院,大连116024 [2]哈尔滨工业大学交通科学与工程学院,哈尔滨150001

出　　处：《同济大学学报（自然科学版）》2010年第2期218-222,共5页Journal of Tongji University:Natural Science

基　　金：国家自然科学基金资助项目(50778057);交通部西部交通科技建设项目(200831800099)

摘　　要：采用移动荷载模式,在有限元方法中利用动态模量主曲线和时间-温度位移因子来表征沥青混合料的力学性质,利用断裂力学的方法分析了温度、车速、裂缝长度和基层类型等对沥青路面Top-Down裂缝裂尖应力强度因子的影响.研究表明随着裂缝长度增加和温度降低,张开型应力强度因子(KⅠ)和剪切型应力强度因子(KⅡ)的峰值增加.行车速度对应力强度因子的作用频率有显著影响,较慢的行车速度会加速Top-Down裂缝的扩展.与采用粒料基层相比,采用半刚性基层可降低裂尖应力强度因子.随着温度升高和裂缝长度增加,KⅠ对裂缝扩展的贡献减小,而KⅡ的贡献逐渐增加.The effects of temperature, vehicle speed, crack length and base type on the stress intensity factor （SIF） at the tip of Top-Down cracking in asphalt pavements under moving load were evaluated by conducting fracture mechanics and finite element （FE） analyses. Dynamic modulus master curves and time-temperature shift factofs were incorporated into the FE model to characterize the mechanical properties of asphalt mixtures. The results show the peaks of tensile type SIF （K I ） and shear type SIF （KⅡ ） increase as crack length increases and the temperature decreases. Vehicle speed has significant influences on the frequency of SIF and slow trafficloading can accelerate the propagation of Top-Down cracking. The use of semi-rigid bases in asphalt pavements can reduce SIF compared to granular bases. The contribution of K I to the propagation of Top-Down cracking becomes less significant, while that of KⅡbecomes more evident when temperature and crack length increase.

关 键 词：沥青路面 Top-Down裂缝 应力强度因子 行车速 度 裂缝长度 移动荷载 

分 类 号：U416.217[交通运输工程—道路与铁道工程]