库水上升条件下不同土体类型岸坡渗流场特征  

Seepage field characteristics of bank slope with different soil types during reservoir water level rise

作　　者：张国超[1] 胡新丽[1] 范付松[1] 赵鑫[1] 

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《煤田地质与勘探》2013年第5期56-61,65,共7页Coal Geology & Exploration

基　　金：国家重点基础研究发展计划(973计划)课题(2011CB710604)

摘　　要：库水位与岸坡体内地下水渗流场的动态变化密切相关。传统的饱和土渗流分析方法无法准确描述水位上升过程中岸坡内渗流场的规律。从饱和-非饱和非稳定渗流理论出发,在室内实验得到基质吸力和体积含水量关系的基础上,通过对实验数据拟合,得出Van Genuchten模型中土水特征参数。以三峡库区典型岸坡为例,模拟库水匀速上升时,坡体为粉质黏土、粉土、砂土和砾石土4种岩土介质类型下的渗流特征,并监测坡面高程为165 m和155 m竖直剖面上的孔隙水压力变化。结果表明:库水位匀速上升过程中岸坡体内浸润线呈"V"字型,并且各时步"V"字型浸润线的拐点连线随渗透性的增大有逐渐与坡面平行的趋势;揭示了4种土体类型孔隙水压力随时间的变化规律。研究成果可为水库岸坡的防治提供较重要的借鉴与参考。There are close relationship between the dynamic changes of seepage field in reservoir slope and reser-voir water level. The traditional analysis methodology based on saturated seepage law can not describe the dynamic change law of seepage in slope while reservoir water level rises. From the theory of unsaturated and transient seepage and on the basis of getting the relationship between matric suction and volumetric water content in labo-ratory experiments, through experimental data fitting, Van Genuchten model parameters of the soil hydraulic char-acteristics have been got. Taking a typical slope in Three Gorges Reservoir area as an example and simulating uni-form water level rise in reservoir, the slope showed seepage characteristics in four soil media, that is silty clay, silty soil, sand or gravel soil, and the pore water pressure change at the elevation of 165 meters and 155 meters of the slope has been monitored. The result shows that the seepage line showed a＂V＂shape in the slope with the uniform water level rise, and at each time step the connection line of the turning point has gradually the trend to be parallel with the slope with increased permeability. The variation regularities of pore water pressure with time in four types of soil have been revealed. The research results can provide important reference for the control of reservoir bank.

关 键 词：岸坡 渗流场 库水位上升 不同岩土介质 VanGenuchten模型 

分 类 号：P642.22[天文地球—工程地质学]