砂夹层黄土路基水分迁移规律  

Water migration rule of loess subgrade with sand interlayers

作　　者：晏长根[1] 邹群[2] 许昱[3] 万琪[1] 石玉玲[4] 马刚峰[5] YAN Chang-gen ZOU Qun XU Yu WAN Qi SHI Yu-ling MA Gang-feng(School of Highway, Chang＇an University, Xi＇an 710064, Shaanxi, China School of Civil and Architecture Engineering, Nanchang Institute of Technology, Nanchang 330099, Jiangxi, China CCCC Highway Consultants Co. , Ltd. , Beijing 100088, China School of Geology Engineering and Geomatics, Chang＇an University, Xi＇an 710054, Shaanxi, China Department of Civil and Environmental Engineering, Old Dominion University, Norfolk 23501, Virginia, America)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]南昌工程学院土木与建筑工程学院,江西南昌330099 [3]中交公路规划设计院有限公司,北京100088 [4]长安大学地质工程与测绘学院,陕西西安710054 [5]欧道明大学土木与环境工程系,佛吉尼亚诺福克23501

出　　处：《交通运输工程学报》2016年第6期21-29,共9页Journal of Traffic and Transportation Engineering

基　　金：国家自然科学基金项目(41272285);中央高校基本科研业务费专项资金项目(2014G2260009);甘肃省交通建设科技项目(2013-03)

摘　　要：以十天高速公路黄土路基为依托,基于土水势原理提出了在路基土层放置砂夹层来减小黄土层浸水沉陷的发展,采用室内模型试验,在黄土路基中部与底部设置砂夹层,模拟了路基毛细水上升、顶面渗水与边坡渗水的情况,分析了路基含水率变化规律及其对路基整体强度和稳定性的影响,并证实了砂夹层的减水阻渗效应。研究结果表明：黄土路基模型初期水分迁移很快,中、后期迁移越来越慢;底部设置砂夹层的路基模块在地下水位上升32d内的体积含水率为24%-27%,纯黄土路基模块的中、下部（路基顶面0.5m以下）的体积含水率约为60%,水分最终的影响深度达到了1.2m;在纯黄土路基模块顶面渗水12d后,体积含水率均超过了60%,而在中部设置了砂夹层的路基模块在夹层下15cm处（路基顶面0.8m以下）的体积含水率小于40%,在25cm处体积含水率小于30%。可见,在压实黄土路基底部与中部设置砂夹层能够阻隔毛细水的上升和减缓水分下渗,减小了路基内部含水率,提高了路基的整体稳定性和强度。Based on the loess subgrade of Shitian Expressway and the principle of soil water potential,laying sand interlayer in the loess subgrade was proposed to reduce the development of collapsibility water immersion.In the indoor model test,the sand interlayers were lain in the middle and bottom of loess subgrade,the seepage of top water,the infiltration of slope water and the capillarity of underground water for loess subgrade were simulated,the variation laws of water content in loess subgrade,their influence on the strength and stability of loess subgrade were analyzed,and their effect of water resistance and leakage resistance for sand interlayers was proved.Test result shows that the migration of water is rapider in initial period and slower in the middle and later periods;under the effect of ground water,the water contents of subgrade with a sand interlayer at the bottom of subgrade are 24%-27% after 32 days,but the water contentsreach to 60%in middle and lower parts（0.5mbelow the top surface）of pure loess subgrade,and the final influence depth of water reaches 1.2m;under the seepage of top water,the water contents of all depths of pure loess subgrade are more than 60% after 12 days,while the water contents of loess subgrade with a sand interlayer in the middle are less than 40% at 15 cm under the interlayer（0.8mbelow the surface of subgrade）,and the moisture content is less than 30%at 25 cm under the interlayer.Obviously,the sand interlayers lay in middle and bottom of compacted loess subgrade can cut off the capillary water and reduce water infiltration,which can decrease the inside water content and increase the whole stability and strength for loess subgrade.

关 键 词：路基工程 黄土路基 含水率 砂夹层 模型试验 水分迁移 

分 类 号：U416.1[交通运输工程—道路与铁道工程]