Impact of waterproofing and drainage systems failures on safety criteria of dams

Abstract

Waterproofing and drainage systems are essential to the structural safety and hydraulic performance of embankment dams. When poorly designed or inadequately maintained, these systems can lead to uncontrolled seepage, internal erosion (piping), and eventual dam failure. This study evaluates the effectiveness of various waterproofing and drainage configurations using the Boughrara dam as a reference model. Through numerical simulations conducted with GeoStudio software, several scenarios were analyzed involving different grout curtain depths, drainage system placements, and core base lengths. The results identified the most effective configuration as a grout curtain 60 meters deep, placed centrally beneath the clay core, paired with a drainage system extending 60 meters downstream of the core. Additionally, a core base length of 43 to 50 meters proved optimal for reducing seepage and improving structural stability. This combination provided the best results in terms of minimizing hydraulic gradient, pore water pressure, and flow rate. These findings highlight the critical role of integrated waterproofing and drainage design in enhancing dam reliability and preventing failure.