Physical and Numerical Modeling of the Formation of Earth Fissures Due to Bedrock Ridges

Groundwater withdrawal from aquifer exploitation leads to differential consolidation, particularly in areas where the bedrock is not uniform, such as in the case of a bedrock ridge. The resulting differential settlements during pumping induce earth fissures due to tensile stresses at the soil surface. This study specifically investigates how the height of a bedrock ridge influences the formation of earth fissures, which arise from increased effective stresses caused by differential soil consolidation. To achieve this objective, physical models were developed using a geotechnical centrifuge. The experimental results were then compared with numerical methods using the finite element method (FEM). The results obtained from the physical models provide a new understanding into the study of fissure formation process caused by a bedrock ridge, specifically in terms of fissure propagation, displacement vector magnitudes, and differential settlements. The numerical modeling, in turn, validated the experimental results by identifying zones where tensile and compressive stresses occur, based on the height of bedrock ridge. The findings indicate that earth fissures originate at the soil surface due to the concentration of tensile strains and propagate downward.