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.

Utilizing a laboratory model test, this study seeks to evaluate the distribution patterns of volumetric moisture content, soil pressure, and pore water pressure within the body of a red mud dam, given varying initial conditions of slope types and ratios, during continuous heavy rainfall. The objective is to investigate the failure mechanisms of a red mud dam under distinct operational conditions during rainfall, thereby offering insights for landslide prevention and ensuring dam construction quality. The results suggest that a stepped red mud dam acts as a buffer platform, altering the seepage direction within the dam and minimizing the water seepage path. When the slope ratio is 1:1, the transient saturated zone is located on the slope face of the dam's body, near the top of the slope, with the saturation time at the first monitoring point occurring 300 s earlier than in a dam with a slope ratio of 1:2. Rainfall affects the distribution of internal forces in the red mud dam body. After rainfall, in the transient saturated zone of the stepped dam body, vertical soil pressure decreases 25% and horizontal soil pressure decreases 6.5%; in the transient saturated zone of the dam with a slope ratio of 1:1, vertical soil pressure decreases 14.8% and horizontal earth pressure decreases 29%; in the transient saturated zone of a dam with a slope ratio of 1:3, the change in soil pressure is small.