摘要
为了研究干线公路沥青路面破坏机理,提高干线公路耐久性,通过对湖南省多条普通干线公路现场调研与路面钻芯分析,对沥青路面半刚性基层产生的断桩、裂缝等病害产生机理进行了研究。选取干线公路重交通等级沥青路面典型结构,建立路面结构分析模型,借助BISAR有限元软件分析在标准轴载和超载30%两种情况下路面的受力状态,同时考虑水平力对应力分布的影响。研究结果表明:垂直荷载越大,剪应力水平越高,车辆超载不影响最大剪应力出现的位置;对比3种基-面层层间结合状态下路面应力应变,发现基面层间一般处于连续或半连续状态,不会出现界面完全光滑状态。计算结果显示:沥青面层小于10 cm的薄层路面结构,高剪应力区位于半刚性基层上,半刚性基层抗剪强度低于承受的剪应力从而引起基层断裂破坏,随着基层强度急剧下降,逐渐产生裂缝、车辙等病害。根据路面病害层位,拟定3种路面结构,分别改变沥青面层和基层厚度,计算不同结构层受力状态,进一步提出普通干线公路路面结构改进措施:重载作用下沥青面层厚度至少提高到12 cm,半刚性基层厚度达到35 cm以上,同时施工过程中做好基面层层间黏结,半刚性基层养生期间严格控制车辆通行,从而达到提高路面疲劳寿命的目的。
In order to study the failure mechanism and improve the durability of asphalt pavement of trunk highway,the mechanism of disease,such as broken pile and cracks of semi-rigid base asphalt pavement,are analyzed based on the field investigation and analyzing pavement drilling core in the area of the common trunk highways in Hunan Province. The stress states of pavement under standard axial load and over 30% of overload are analyzed by means of BISAR finite element software after selecting the typical structure of heavy traffic graded asphalt pavement of trunk highway and establishing the analysis model of pavement structure with consideration of influence of horizontal force on stress distribution. The study result shows that the higher the vertical load,the higher the shear stress level,and overloading does not affect the location of maximum shear stress. By comparing the stresses and strains in 3 kinds of interlaminar binding states,it is found that it is generally in continuous or semi-continuous state and the interface will not be completely smooth. The calculation result demonstrates that（ 1） in the thin layer pavement structure with asphalt surface less than 10 cm,the high shear stress zone is located on the semi-rigid base,the shear strength of semi-rigid base islower than the shear stress,which causes the fracture of base course.（ 2） With the rapid decline of base strength,cracks,rutting and other diseases gradually occur. According to the pavement disease layer,3 kinds of pavement structure are proposed. The stress states in different structure layers are calculated when changing base and surface thicknesses respectively. The improvement measures of common trunk highway pavement structure are put forward： to increase the asphalt surface layer thickness to at least 12 cm under the heavy load,the thickness of semi-rigid base should reach more than 35 cm,and the interlaminar binding must be ensured in construction process and vehicle traffic must be strictly controlled during semi-rigid base curing period to improve the fatigue life of pavement.
作者
邹静蓉
张治强
李涛
ZOU Jing-rong, ZHANG Zhi-qiang, LI Tao(Central South University of Forestry and Technology, Changsha Hunan 410004, Chin)
出处
《公路交通科技》
CAS
CSCD
北大核心
2018年第5期1-7,48,共8页
Journal of Highway and Transportation Research and Development
基金
湖南省交通科技项目(201402)
关键词
道路工程
破坏机理
有限元分析
干线公路沥青路面
改进措施
road engineering
failure mechanism
finite element analysis
trunk highway asphaltpavement
improvement measure
