The impact of groundwater level rise on toppling failure in anti-dip slopes: A physical model study

The rise in groundwater levels can trigger large-scale toppling failures in anti-dip slopes, posing serious risks to life and property. However, current static model experiments often overlook the effects of full water saturation of the rock mass and the continuity of water pressure, leading to some deviation in experimental results. This study addresses these limitations by simulating continuous groundwater pressure in a physical model and thoroughly considering the water content of the rock mass to investigate the impact of rising groundwater levels on the stability of anti-dip slopes. The results indicate that the failure mode of the toppling slope is toppling-sliding failure, characterized by both staged and sudden collapse. The rise in groundwater levels is a primary cause of toppling failures. On one hand, it increases the water content and reduces the strength of the rock mass at the slope toe and the water pressure on both sides produces shear force leading to shear slip, on the other hand, groundwater pressure contributes positively to the toppling failure, resulting in both shallow toppling failures and deep tensile cracks. The study suggests that constraining the slope toe can enhance the stability of anti-dip slopes.