Influence of combination of the cutoff wall and horizontal drainage on seepage characterization in earth dam foundations
- Vol.53(5), Oct
- USA Springer 2023
- 995-1010p.
Injections and drainage are frequently used in combination to treat the dam foundations, with the aim of improving the mechanical and hydraulic characteristics of the foundation soils. In most cases, it is a matter of exploring and optimizing the best compromise between these two treatment processes. This study aims to investigate the simultaneous influences of cutoff wall and horizontal drain on the characterizations of seepage at the level of dam foundations, notably the uplift pressure, discharge seepage, and exit gradient. By taking into account the case of Sidi Abdelli earth dam in Algeria. The purpose of this paper is to analyze the influence of the conceptual criteria such as the cutoff wall and horizontal drain on the seepage characterization into the dam foundations. The results revealed that the influence of cutoff wall depth is significant concerning its permeability. Indeed, for the cutoff wall with the lowest permeability and a penetration depth of 75% into the foundation, the exit gradient and discharge seepage are reduced by around 38% and 22.35%, respectively. A decrease in uplift pressure is also recorded. An increase in the horizontal drain length to 150 m with the impermeable cutoff wall penetrating the foundation about 75 m constitutes the most appropriate design criteria in relation to seepage. The uplift pressure on downstream side of the dam was reduced by decreasing the permeability of cutoff wall with increasing the length of horizontal drain.