Research On Calculation Method Of Seepage Discharge For Complicated 3-D Seepage Flow Field Based On FEM

Seepage discharge is an important guidepost in seepage calculation and one of the problems in seepage calculation and analysis is to forecast seepage discharge accurately. According to the request of project the calculation method of seepage discharge for complicated 3-D seepage field based on FEM are studied in this dissertation The validity and the veracity of this new calculation method will be proved by comparison. The paper includes the following contents:1. On the base of basic seepage theory, the deduction of Darcy'law and the basic equations on seepage problem are deduced in detail. The basic concepts related to the seepage problem such as parameter, condition of finite solution and mathematic model are all explainted.2. The solutions which are used to solve the seepage calculation of finite element with free surface are introduced. The two calculation methods of seepage discharge, namely mid-section method and nodal equivalent method are stress explained. The basic theory and deduction of above two method are introduced.3. From definiens of seepage discharge by using basic theory of finite element method and transform of isoparameter element, the calculation method of seepage discharge between two random planes is introduced and the iteration formula which used to calculate the seepage discharge of random point is deduced. The iteration formula then is used to develop program for calculation of seepage discharge.4. Three calculation models, homogeneous rectangle dam, sand launder, and dyke are used to prove the rationality of new calculation method introduced in this paper and the validity of relative calculation program. By comparison, it is shown that the calculation result of seepage discharge obtained by using the method introduced in this paper is more precise.5. Calculation for controlling seepage discharge in the dam site of Bakun Hydropower Project in Malaysia and calculation on seepage discharge of drainage wells in the foundation pit of Jinnah Hydropower Project in Pakistan are taken as examples to prove the advantage and practicability of the calculation method for seepage discharge introduced in the paper.