Evaluation of Structural Suitability and Seepage Characteristics of L-Type Retaining Wall to Prevent Overtopping in Agricultural Reservoirs

Aging agricultural reservoirs are prone to increasing number of failures due to their overtopping. In this study, an L-type retaining wall was designed on a dam crest, and large-scale indoor model experiments were conducted to evaluate the seepage and deformation behavior as a function of buried depth and water-level variation. Experiments were conducted considering two buried depths, G.L -3 cm and G.L -7 cm from the dam crest, and three water levels, flood level, dam crest level, and overtopping level. Under both the buried depths, the saturated zone at the contact area between the dam crest and structure increased under the overtopping level condition, indicating potential risks. However, no seepage or deformation was observed, suggesting that the structure could effectively prevent failure. The pore water pressure exhibited similar behavior under both the buried depths, indicating that drainage through the filter was effective in dissipating the pressure. The horizontal and vertical displacements were significantly lower than the standard thresholds for the dam crest condition, suggesting that if the interface between the dam body and structure is properly managed, the results of this experiment may serve as a potential alternative solution to prevent overtopping-induced failures.