Discussion on Computing Method of Dam Foundation Seepage and Bypass Seepage of Dam Abutment

Based on the theory of conformal mapping in complex function and numerical analysis method,the analytic solution of two-dimensional seepage model of dam foundation is derived.Based on the numerical analysis software,the calculation formula of leakage per unit width of dam foundation and basement uplift pressure are given with and without anti-seepage curtain.Taking gravity dam for an example,the impervious curtain depth is analyzed.The restraining effect of uplift pressure is not obvious when the depth of the impervious curtain is greater than the dam bottom width.Under the same depth impervious curtain,the basement uplift pressure increases with the pervious layer thickness reduces.When the thickness of permeable layer approaches the depth of curtain,the basement uplift pressure begins to decrease gradually.It appears the phenomenon ofclosing door.The analytic formula of the amount of leakage bypass seepage of dam abutment without anti-seepage curtain is given by integration theory.By compared engineering examples and the results obtained by finite element method,it demonstrates that the calculation method is convenient and it has reliable accuracy.