Simulation Of Earth Dam Seepage With A Physics-based Numerical Model

Hydraulic factors are always important in embankment engineering. Seepage is one of the most dangerous because it is difficult to monitor. As one of the most popular dam types, earth dam is very sensitive to seepage. It is extremely important for extra attention to be paid to this problem since most of the earth dam failures were caused by seepage.In this dissertation, the seepage processes of earth dams under complex conditions were simulated by using a physics-based hydrological model: Integrated Hydrology Model (InHM). Phreatic surface, seepage discharge, and seepage velocity were analyzed to study the characteristics and mechanism of earth dam seepage.Both the steady-state seepage and the transient seepage were simulated and analyzed in this dissertation. The simulation scenarios considered different steady water head, various thickness of the clay core, with/without drainage structure, and the rising/declining of the water level. The seepage in upslope under drawdown condition was investigated in detail since it is the most dangerous condition.Following conclusions were generated by this study:1. The water head is the driving force for the seepage in earth dams;2. Related to seepage, the most dangerous locations include 1) the seepage face near the dam toe and 2) in the dam, around the downstream side of clay core;3. The efficiency of the clay core is related to its thickness: not necessarily the thinner the better4. The drainage structure has both positive and negative effects in seepage control;5. The transient seepage caused by changing water level is extremely complex and need to be handled carefully.