Evaluation

Three design methods are usually used in the analysis and design of ground water control systems. These methods are: the analysis using equilibrium formulas, the analysis using flow net and the analysis through numerical modeling. Numerical ground water models have proven to be essential when dealing with complex aquifer situations. One of the most known numerical models is “Modflow” which is a three dimensional finite difference model oriented for ground water modeling. The dewatering activities that take place at the Banha power station was utilized in calibrating the performance of the numerical modeling process. A parametric study was carried out with different configurations and boundary conditions. The study covers the performance of sand drains with different depths and spacing. These readings had been compared to “Modflow” results and good agreement between the field data and the analysis results had been observed. For complex ground water control problems where the assumptions of the conventional equilibrium formulas are not valid, the use of these formulas may lead to serious errors in design. In this condition, the use of 3-D finite difference analysis is essential to obtain reliable results and design for a groundwater control system.