Study On Seepage In The Dam Base Of Xiaolangdi Project On Yellow River

Xiaolangdi project is an important hydraulic engineering on Yellow River. Security analysis about the dam needs a study on seepage in the dam and the dam base. The results of seepage analysis are so important that they can be used to supervise antiseep measures for guaranteeing benefits from Xiaolangdi project.According to historical reconnaissance data about geology, engineering geology and hydrological geology, the topographical features, strata and engineering structure were researched in the thesis. And this area was divided a few subfields based on hydrogeologic condition. At the same time, rainfall frequency was counted. Moreover, the author amply analyzed the system of drains and impervious elements of the project and osmometers'situation, and contrasted exudation pressure with water height of the reservoir and water percolating capacity. On this condition, catching abnormal attribute of water percolating capacity in a downstream pond and utilizing Darcy's law, one infiltration pathway which is in the rock stratum of the left bank was found, the main source of seepage quantity in the downstream pond was concluded, and a detailed explanation for abnormal attribute was put forward.In succession, through simplifying geological conditions, the author built a hydrogeologic model about research area. Then the author simulated the flow field of the dam base by FEFLOW (Finite element subsurface flow & transport simulation system) software. At last, giving the relation between seepage quality of the downstream pond and water level of the reservoir, the data about exudation pressure, the exudation pressure gradient in the key position, and infiltration pathway, the conclusion can be asserted that the dam is in well condition.