堆积体滑带土非饱和-饱和渗透特性试验研究  

Experimental study of unsaturated-saturated permeability characteristics of slip soil in landslide deposits

作　　者：李跃 徐卫亚[1,3] 易魁 谢伟超 张强[5] 孟庆祥[1,3] LI Yue;XU Wei-ya;YI Kui;XIE Wei-chao;ZHANG Qiang;MENG Qing-xiang(Research Institute of Geotechnical Engineering,Hohai University,Nanjing,Jiangsu 210098,China;Department of Civil and Environmental Engineering,University of Waterloo,Ontario,Canada;Key Laboratory of Geomechanics and Embankment Engineering,Ministry of Education,Hohai University,Nanjing,Jiangsu 210098,China;Huaneng Lancang River Hydropower Inc.,Kunming,Yunnan 650206,China;Research Institute of Geotechnical Engineering,China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]河海大学岩土工程研究所,江苏南京210098 [2]滑铁卢大学土木与环境学院,加拿大安大略省 [3]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [4]华能澜沧江水电股份有限公司,云南昆明650214 [5]中国水利水电科学研究院岩土工程研究所,北京100038

出　　处：《岩土力学》2021年第5期1355-1362,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金重点项目(No.51939004);国家自然科学基金(No.11772118);国家重点研发计划(No.2017YFC1501100);华能集团公司重点科技项目(No.HNKJ18-H24)。

摘　　要：我国西南地区水电工程近库坝区发育有大量的滑坡堆积体,这些堆积体在降雨、库水位升降等水动力条件下极易沿既有滑带产生变形和破坏。以澜沧江流域大华桥水电站大华滑坡为例,针对其滑带土开展了土-水特征曲线试验,分析了非饱和渗透过程的特性及演化规律,研究了不同围压和不同渗压条件下的饱和渗透特性。研究结果表明,采用VG模型可较好地描述大华滑带土的土-水特征曲线及其相对渗透系数的变化规律;通过饱和渗透试验分析发现,在相同条件下围压越大,滑带土的饱和渗透能力越弱,而渗压越大,饱和渗透能力越强,且滑带土饱和渗透表现出较强的非Darcy流特征,其渗透速度与水力坡降之间满足Forchheimer二项式关系,且当围压较低时,速度一次项对渗透的影响更显著。而随着围压增加,速度二次项逐步占据主导。There are many landslide deposits in the reservoir and bank areas of hydropower projects in southwest China.These deposits are easy to deform and fail along the existing sliding zone under hydrodynamic conditions,such as rainfall and reservoir water fluctuation.The slip soil in Dahua landslide deposits which are located at the Dahuaqiao Hydropower Plant in the Lancang river basin of southwest China,was studied as an example.The experimental study was carried out to explore the soil-water characteristic curve(SWCC)of slip soil.The permeability characteristics and the evolution in the unsaturated seepage process were analyzed,and the saturated permeability characteristics under different confining pressures and seepage pressures were studied.The results indicated that the VG model could be used to describe the SWCC and the variation of relative permeability coefficient of Dahua slip soil.Through the saturated permeability test,it is found that under the same other conditions,the larger the confining pressure is,the weaker the saturated permeability of the slip soil is;while the larger the seepage pressure is,the stronger the saturated permeability is.Furthermore,the saturated permeability characteristics of the slip soil manifested a strong non-Darcy flow behavior,and the relationship between permeability velocity and hydraulic gradient satisfied the Forchheimer binomial model.When the confining pressure was low,the linear term coefficient of velocity had a more significant effect on the permeability,whereas the quadratic term coefficient of velocity gradually dominated in the seepage process with the increase of confining pressure.

关 键 词：堆积体滑带土 非饱和-饱和渗透 土-水特征曲线 非DARCY渗流 水动力型滑坡 

分 类 号：TU411[建筑科学—岩土工程]