Underdrain Systems for Large Structures Placed Below the Groundwater Table.

This research is a study in seepage analysis for engineered structures built below the groundwater table in particular an analysis of underdrain systems for such structures. General seepage theories and design considerations are discussed as part of the literature review. Also design concepts and methods of analysis are covered which gives a brief overview of design considerations and techniques which are currently used for this type of seepage problem. Key variables to the design of an underdrain system are studied in detail by using a two dimensional, steady state finite element model. Such variables studies are drain spacing, drain width, anisotropic hydraulic conductivity, thickness of the aquifer, head differential and sloping aquifers. Results are presented in the form of dimensionless plots and nomographs for drain discharge and free surface plots for the different variables studied. Author