Size Effects of Rough Fracture Seepage in Rocks of Different Scales

Percolation experiments were conducted on coal samples with various fracture lengths and inclination angles under different stress conditions using a gravity-loaded rock percolation test device. The goals of these are (1) to improve the technology for protecting water resources while mining (2) enhance research how size effects affect seepage. A three-dimensional seepage model was constructed COMSOL numerical simulation software larger ranging from 1 30 m investigate pattern coupling roughness, width, other factors. Multiple regression analysis used factors large small fractures independently. results show that, laboratory conditions, 10–70 mm (small length), permeability increases non-linearly an increase in length, overall is approximately 1.8 times. Whereas, 1–30 (large length) simulation, decreases then change 0.03 varies three stages (1–8 obvious change, 8–23 stabilization, 23–30 stability) lengths, widths, roughness conditions. Acritical found exist. effect length further verified by parameter sensitivity. this study reveal mechanism geometry stress.