Simulation Experiment on Shaft Deformation Induced by Mining Subsidence under Similar Gravity Field in Deep Soil Strata

Abstract To address the shaft deformation issues resulting from mining solid mineral resources in areas with deep soil and thin rock strata, a geotechnical model experiment, namely the seepage force model test, was conducted to simulate the effect of mining disturbance on shaft deformation in the soil section. This simulation was complemented by monitoring data from the model shaft, which allowed the determination of deflection displacements at different protection areas. The results show that there exists an approximately linear relationship between the maximum horizontal displacement of the shaft and the thickness of the mining coal seam. The shaft protection areas in the soil section were redesigned by changing the movement angle from the original 45° to 37.6°. The maximum horizontal displacements of the prototype shaft were reduced to 73.8 mm, 112.7 mm, and 170.9 mm for mining coal thicknesses of 2.7 m, 5.3 m, and 8.0 m respectively, which are 26%, 24.6% and 26.7% of the original design shaft displacements. Combined with the probability integral method, the simulation test results for the shaft protection rock pillars were thoroughly analyzed, leading to the development of a more rational and reliable design approach for the shaft protection rock pillars in regions with deep soil and thin rock strata. These research results are of great significance for effectively preventing and managing mining-induced subsidence disasters, while ensuring the optimal design of shaft protection areas.