基于有限元的温度-荷载-行车速度耦合作用下路面结构动孔隙水压力对比研究  

Comparative Study on Dynamic Pore Water Pressure of Pavement Structure under Coupling of Temperature,Load and Driving Speed Based on FE Method

作　　者：杨新燕 YANG Xin-yan(Fujian Communications Planning and Design Institute Co.,Ltd.,Fuzhou Fujian 350004,China)

机构地区：[1]福建省交通规划设计院有限公司,福建福州350004

出　　处：《公路交通科技》2021年第5期23-30,共8页Journal of Highway and Transportation Research and Development

摘　　要：为研究不同沥青路面基层的水损坏形态,选取半刚性基层与级配碎石基层为研究对象,以动空隙水压力的变化情况为研究指标,基于有限元法建立理论模型预测了不同温度-荷载-行车速度耦合作用下不同基层结构的动孔隙水压力的变化规律,并进行了对比分析。结果表明:在标准条件(荷载0.7 MPa,车速80 km/h,温度20℃)和不利条件(荷载0.9 MPa,车速120 km/h,温度63℃)2种耦合条件下,级配碎石基层都能够极大降低沥青层的动孔隙水压力,特别是对于降低9 cm以下结构的动孔隙水压力,下面层底部降低幅度最大可达94.0%(标准条件)和95.3%(不利条件),从而能够显著降低结构性水损坏的产生;半刚性结构的最大动水压力产生的层位(18 cm)和最大值(正压力587.9 kPa)及增加的幅度(68.4%)均大于相应的级配碎石结构(6 cm,正压力382.2 kPa,40.8%),半刚性结构在不利条件下敏感性更大,更加容易产生结构性水损坏。因此设置级配碎石基层可增加结构内部的渗水,降低动水压力,特别是中下面层内部的动孔隙水压力,提高结构抗水损坏性能,减少多雨潮湿条件下的沥青路面水损坏。In order to study the water damage of different asphalt pavement bases,selecting semi-rigid base and graded-gravel base as the research objects,taking the change of dynamic pore water pressure as the research indicator,a theoretical model is established based on FE method,the change rules of dynamic pore water pressure of different base structures under the coupling action of different temperatures,loads and driving speeds are predicted,and the comparative analysis is carried out.The result shows that(1)Under the coupling conditions of standard condition(load of 0.7 MPa,vehicle speed of 80 km/h and temperature of 20℃)and unfavorable condition(load of 0.9 MPa,vehicle speed of 120 km/h and temperature of 63℃),graded crushed stone base can greatly reduce the dynamic pore water pressure of asphalt layer,especially for reducing the dynamic pore water pressure of the structure below 9 cm,the maximum reduction of the bottom layer can reach 94.0%(standard condition)and 95.3%(adverse condition)respectively,which can significantly reduce the occurrence of structural water damage.(2)The depth(18 cm),maximum value(positive pressure of 587.9 kPa)and increasing range(68.4%)generated by the maximum hydrodynamic pressure of semi-rigid structure are larger than those of corresponding graded gravel structure(6 cm,positive pressure of 382.2 kPa,40.8%).Semi-rigid structure is more sensitive under adverse conditions and is more prone to structural water damage.Therefore,setting graded gravel base layer can increase the water seepage inside the structure,reduce the dynamic water pressure,especially the dynamic pore water pressure inside the middle and lower surface layers,improve the water damage resistance of the structure,and reduce the water damage of the asphalt pavement under rainy and humid conditions.

关 键 词：道路工程 动孔隙水压力 有限元 级配碎石基层 预估模型 

分 类 号：U416.03[交通运输工程—道路与铁道工程]