An Investigation On Foundation Seepage And Seepage Control Of Gate Dam By Finite Volume Method

Bad foundation seepage control results in many seepage accidents, so it is very important to research foundation seepage of gate dam. It is lack of numerical simulations by finite volume method though there are a lot of numerical works using other methods. Foundation seepage and seepage control of gate dam are investigated in combination with Jinshaxia hydroelectric power station in this paperFirst, finite volume method is introduced, and exact solution is validated. Measures, rules and basic demands of seepage control is reviewed about grit foundation. Usually, impervious blanket and impervious wall are adapted for seepage control of gate dam and other hydraulic structures in projects. The seepage control effect and project cost are different. In this paper, the combination of them is studied, and the best combination of impervious blanket and impervious wall is found.Usually, curtain and drainage are adapted for seepage control of gravity dam, and they are studied in this paper. In case of setting curtain merely, its reasonable depth is found for deep impervious blanket and shallow impervious blanket is discussed. The effect of thickness and place of curtainon seepage discharge and uplift of dam foundation for deep impervious blanket are analyzed. In case of setting drainage merely, determinant of the effect of it is found. The conclusion is educed that there is a reasonable depth when drainage is set and the effect of drainage diameter and drainage space on seepage discharge and uplift of dam foundation is studied. In case of setting drainage and curtain together, the effect of increasing curtain depth on seepage discharge and uplift of dam foundation is studied when drainage depth is fixed. The effect of increasing drainage depth on seepage discharge and uplift of dam foundation is studied when curtain depth is fixed.In this paper, the four projects are calculated for sluice foundation, and that is two-dimensional calculation taking into drainage, two-dimensional calculation taking no account of drainage, three-dimensional calculation taking into drainage and three-dimensional calculation using grid adapt around drainage. The result makes it clear that it is very important that grids around drainage are set off reasonably for calculating seepage field. For the joint part of earth dam and sluice foundation, the two projects are calculated, that is taking into earth dam body seepage and taking no account of earth dam body seepage. For the former, the longitudinal and cross flow patterns of the whole seepage field are calculated. For the later, reliability is increased by. adapting the grids around drainage.