摘要
中国北疆地区大型渠道基土多为白砂岩和泥岩,其水力特性决定着渠道结构病害的形成与发育。为此以新疆阿勒泰北屯灌区的白砂岩、泥岩为研究对象,测试其物理力学和抗渗各项指标;根据非饱和土理论,采用滤纸法得到其土水特征曲线,并基于Gardner模型、Van Genuchten模型和Fredlund&Xing模型对土水特征曲线进行参数拟合并分析其持水特性;结合其土水特征曲线进一步采用Childs&Collis-Geroge模型研究了其非饱和渗透曲线。试验结果表明:白砂岩、泥岩具有膨胀性且为低渗透性土体。白砂岩抗剪强度高、压缩性低。白砂岩、泥岩土水特征曲线拟合效果最好的分别是GA模型、VG模型,泥岩较白砂岩的持水性能更好。相对渗透系数随基质吸力增加而急剧降低,一定基质吸力范围内两者在双对数坐标系中呈直线型曲线。
The foundation soil of large channels in northern Xinjiang is mostly white sandstone and mudstone,and its hydraulic characteristics determine the formation and development of channel structural diseases.To this end,the white sandstone and mudstone of Beitun Irrigation in Altay,Xinjiang are taken as the objects to test their physical mechanics and impermeability indexes.According to the theory of unsaturated soil,the soil-water characteristic curve is obtained by the filter paper method,and based on the Gardner,Van Genuchten and Fredlund&Xing models the parameters of the soil-water characteristic curve is filled and their water-retention characteristics are analyzed;combined with the soil-water characteristic curve.Combined with its soil-water characteristic curve,the Childs&Collis-Geroge model is used to study the unsaturated permeability curve.The results show that the white sandstone and mudstone are expansive and low-permeability soil.The white sandstone has high shear strength and low compressibility.The best fitting effect of the SWCC of white sandstone and mudstone are the GA model and VG model,respectively,and mudstone has better water-retention performance than the that white sandstone.The relative permeability coefficient decreases sharply with the increase of matrix suction.Within a certain range of matrix suction,they are linear curves in a double-logarithmic coordinate system.
作者
谭志翔
王正中
葛建锐
江浩源
刘铨鸿
孟晓栋
TAN Zhi-xiang;WANG Zheng-zhong;GE Jian-rui;JIANG Hao-yuan;LIU Quan-hong;MENG Xiao-dong(Cold and Arid Regions Water Engineering Safety Research Center,Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education,Northwest A&F University,Yangling 712100,China;State Key Laboratory of Frozen Soil Engineering,CAS,Lanzhou 730000,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2020年第S01期229-233,共5页
Chinese Journal of Geotechnical Engineering
基金
国家重点研发计划项目(2017YFC0405102)
国家自然科学基金项目(51279168)
冻土工程国家重点实验室开放基金项目(SKLFSE201801)
关键词
白砂岩与泥岩
土水特征曲线
滤纸法
基质吸力
渗透系数
white sandstone and mudstone
soil-water characteristic curve
filter paper method
matrix suction
permeability coefficient function
