降雨条件下炭质泥岩-土分层路堤含水特征试验  

Moisture characteristics test of carbonaceous mudstone-soil stratified filling embankment under the rainfall condition

作　　者：曾铃[1,2] 邱祥[3] 付宏渊[3] 周功科 陈向阳 ZENG Ling QIU Xiang FU Hong-yuan ZHOU Gong-ke CHEN Xiang-yang(Key Laboratory of Road Structure and Material of Ministry of Transport, Changsha University of Science Technology, Changsha 410076, Hunan, China School of Civil Engineering and Architecture, Changsha University of Science ＆ Technology, Changsha 410004, Hunan, China School of Traffic and Transportation Engineering, Changsha University of Science ＆ Technology, Changsha 410004, Hunan, China Co-Innovation Center for Advanced Construction and Maintenance Technology of Modem Transportation Infrastructural Facility, Changsha 410004, Hunan, China)

机构地区：[1]长沙理工大学道路结构与材料交通行业重点实验室,湖南长沙410076 [2]长沙理工大学土木与建筑学院,湖南长沙410004 [3]长沙理工大学交通运输工程学院,湖南长沙410004 [4]现代公路交通基础设施先进建养技术湖南省协同创新中心,湖南长沙410004

出　　处：《长安大学学报（自然科学版）》2016年第5期29-36,共8页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(51278067,51578079,51508040,51508042);湖南省自然科学基金项目(2016JJ3010);长沙理工大学土木工程重点学科创新性项目(15ZDXK08);长沙理工大学道路结构与材料交通行业重点实验室开放基金项目(kfj140302)

摘　　要：为研究降雨条件下炭质泥岩-土分层填筑路堤的含水特征,采用室内试验与数值模拟相结合的研究方法,开展人工模拟降雨的路堤物理模型试验,分析雨水入渗时路堤内部含水率的变化特征、暂态饱和区演化过程,并结合数值试验对试验结果进行了验证。研究结果表明:短时降雨对路堤表层土体含水率影响较小,随着降雨的持续,其影响程度增大;受填筑形式的影响,各截面含水率分布曲线呈"S"形或倒"S"形;路堤边坡坡面以下同一深度处土体含水率增大的幅度和速率与其高程呈反比,路堤内部同一高程处土体含水率增大的幅度和速率与其距坡面的距离呈反比;降雨入渗形成的暂态饱和区由坡面向路堤内部整体扩展,其上部扩展速度小于路堤下部,同时在预崩解炭质泥岩中的扩展速度快于土中的速度,当暂态饱和区扩展到一定深度后将引起地下水位的升高;模型试验人眼观察的局限性、填筑过程中水分的迁移及尺寸效应,使得模型试验与数值试验结果之间存在一定差异;路堤特征点、截面含水率变化特征以及暂态饱和区分布形式的研究试验成果,对开展炭质泥岩-土分层填筑路堤在降雨条件下的后续崩解机理及失稳模式研究具有参考意义。To study the moisture characteristics of carbonaceous mudstone-soil stratified filling embankment in the rainfall condition, combined laboratory model test with numerical simulation, the embankment model test under the condition of artificial rainfall was carried out, the variation of water content evolution of transient saturation zone in the embankment during the rainwater infiltration were analysed, and the test results were verified by numerical experiment. Theresults show that short term rainfall has little impact on water content ol surtace SOl[ OI embankment. The impact increases as the rain continues, and with the influence of filling forms, moisture content curve of every cross section presents ＂S＂ shape or inverted ＂S＂ shape. The increased magnitude and the rate of soil moisture content under the same depth of embankment slope is inversely proportional to elevation, the increased magnitude and the rate of soil moisture content under the same depth of the embankment internal is inversely proportional to the distance to the surface of slope. Transient saturated zone caused by rainfall extends from surface to internal of embankment, the extending speed at top of the embankment is smaller than that at the bottom. At the same time, the extending speed at the pre-disintegrating carbonaceous mudstone is faster than that at the soil. When the transient saturation zone extends to a certain depth, it may cause the rising of groundwater. The limitations of visual observation and moisture migration of filling process and the size effect of model experiment load to some differences between the results of model experiment and the consequence of numerical experiment. Through the exploration of the variation of moisture content of embankment characteristic and the cross section, and the distribution form of transient saturation zone, the test results have reference significance for the study of the subsequent disintegration mechanism and the design of slope drainage and the unstable model of carbonaceo

关 键 词：道路工程 炭质泥岩 降雨条件下 模型试验 含水特征 

分 类 号：U411[交通运输工程—道路与铁道工程]