A self-designed water level control system was used to simulate the collapse of a red mud dam in a dry storage yard under varying water levels. The study unveiled the distribution patterns of seepage lines, pore water pressure, soil pressure, and crack evolution in red mud dams with varying slope ratios (1:2 and 1:1) under changing water levels. Experimental findings show that the rise of the infiltration line is initially rapid, then slows down, exhibiting a lag effect. The area with the highest pore water pressure beneath the infiltration line also experiences the highest horizontal soil pressure. Under different slope ratios, the reasons for the formation of main cracks are different. When the slope ratio is 1:2, under the combined action of gravity and hydraulic forces, slope cracks are generated due to the formation of a through channel extending from the interior of the red mud dam body to the slope surface. When the slope ratio is 1:1, cracks appear at the dam crest due to the traction effect of the sliding slope below the infiltration line on the upper slope. The stress and seepage fields of red mud dams with different slope ratios were analyzed using the finite element software ABAQUS, revealing the stress and displacement distribution patterns on the dam slope surface.

Seepage damage is a significant factor leading to red mud tailings dam failures. Laboratory tests on seepage damage were conducted to investigate the damage characteristics and distribution laws of red mud tailings dams, including soil pressure, infiltration line, pore water pressure, dam displacement, and crack evolution. The findings revealed the seepage damage mechanisms of red mud slopes, offering insights for the safe operation and seepage damage prevention of red mud tailings dams. The results showed that the higher the water level is in the red mud tailings dam, the higher position the infiltration line is when it reaches the slope face. At the highest infiltration line point of the slope surface, the increase of pore water pressure is the highest and the change of horizontal soil pressure is the highest. Consequently, increased pore water pressure leads to decreased effective stress and shear strength, increasing the susceptibility to damage. Cracks resulting from seepage damage predominantly form below the infiltration line; the higher the infiltration lines is on the slope surface, the higher the position of the main crack formations is. The displacement of the dam body primarily occurs due to the continuous expansion of major cracks; the higher the infiltration lines are on the slope surface, the larger the displacement of the dam body is.