横观各向同性沥青路面结构动力响应分析  

Analysis on Dynamical Response of Cross-anisotropic Asphalt Pavement Structure

作　　者：颜可珍[1] 胡迎斌 游凌云[1] 刘能源[1] 庾付磊 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]郑州市政工程勘测设计研究院,河南郑州450052

出　　处：《公路交通科技》2017年第5期1-9,共9页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(50808077;51278188)

摘　　要：考虑到沥青混合料、级配碎石和土基等材料具有明显的横观各向同性特性,采用有限元分析方法研究了FWD荷载作用下横观各向同性沥青路面结构的动力响应。分别考虑了不同水平下沥青面层、碎石基层及土基的横观各向同性特性,研究结构层材料的水平方向弹性模量与竖直方向模量比对路面的动力响应影响规律,并根据AI破坏准则对其服务寿命进行了预估分析。结果表明,面层和基层的模量比对路面动力响应和服务寿命影响较大:面层和基层弹性模量比对沥青层底应力应变及土基底部压应变影响都很显著,基层模量比对路表弯沉影响也较大;当面层模量比减小到0.2时,控制疲劳开裂和车辙的荷载重复作用次数分别减小了87%和65%,当基层模量比减小到0.17时,则分别减小了82%和59%;土基模量比对路面结构动力响应和服务寿命影响较小。基于各向同性特性的现行路面设计偏于危险,应适当考虑道路材料的横观各向同性特性。Considering that asphalt mixtures, graded macadam and soil subgrade and so on are obviously cross-anisotropic, the dynamic response of eross-anisotropie asphalt pavement structure under FWD load is studied by finite element numerical analysis. Taking the different degrees of cross-anisotropy of asphalt surface course, crushed stone base course and soil subgrade into consideration respectively, the effect law of the ratio of structural layer material＇s elasticity modulus in horizontal to that in vertical direction on dynamic response of asphalt pavement is investigated, and the service life is predicted based on AI principle. The result shows that （ 1 ） the ratios of elasticity moduli of surface course and base course have great impact on the stresses and strains at the bottom of asphalt layer and the compressive strains at the bottom of soil subgrade are greatly, and the surface deflection is obviously affected by the modulus ratios of base course; （2） when the ratio of elasticity modulus of asphalt surface course reduced to 0. 2, the number of load repetition to prevent fatigue cracking and rutting reduced by 87% and 65% respectively; （3） when the ratio of base course reduced to 0. 17, they reduced by 82% and 59% respectively; （4） the modulus ratio of soil subgrade has relatively small impacts. The currently-adopted pavement design based on isotropy is comparably unsafe, the eross-anisotropic properties of road materials deserve appropriate consideration.

关 键 词：道路工程 沥青路面 有限元模拟 横观各向同性 动力响应 

分 类 号：U416.217[交通运输工程—道路与铁道工程]