A comparison of theoretical and experimental behaviour of a model dam in terms of seepage

In Civil and Geotechnical engineering a thorough knowledge of pore water seepage analysis is critical for the design of dams and structures where a water table is encountered. The following dissertation will primarily look at analysing pore water seepage rates, a background of all seepage failure mechanisms and the standards that govern it. The main objective of this dissertation is to create a model dam and compare the experimental rates of seepage with theoretical values. Permeability is the primary factor which affects seepage rates, it is a measure of the transmissivity of a soil, with the coefficient of permeability (k) the name given to the physical parameter. Methods of experimentally and empirically estimating the coefficient of permeability were identified and adopted as part of the theoretical calculation of seepage rates under a model dam. By means of a drainage and seepage tank, an experimental model dam was constructed. The dam formed the basis of a seepage rate analysis to compare with the theoretical methods of analysis for steady state flow conditions. Finite element computer analysis and the method of flow nets were utilised to produce the theoretical comparisons. The dissertation establishes that it is possible to produce experimental results that are comparable within 10% of theoretical results with an experimental approach for determining the coefficient of permeability. The dissertation also establishes that it is problematic to accurately assess the coefficient of permeability with variations in temperature causing changes to the viscosity of the water and thus affecting the permeability and results if not considered. The empirical methods of determining coefficient of permeability underestimated the flow by circa 60 % for the Prugh method, the Hazen method with correction factors overestimated the quantity of flow by circa 30 %