Analysis on the stability of dissolved area of glauberite mined by water-soluble method in a mine

This study investigates the stability of dissolution zones formed during chamber solution mining at the Pengshan Tongle glauberite mine. An integrated approach combining laboratory leaching experiments and FLAC3D numerical simulations was adopted to systematically evaluate the volumetric changes of dissolved materials and their impact on structural stability. A 3D numerical model was developed to analyze stress distribution, displacement patterns, plastic zone evolution, and surface subsidence. Experimental results reveal that dissolution shrinkage increases with higher glauberite content and decreases with larger ore particle size. Numerical analyses further demonstrate that the dissolution contraction ratio plays a critical role in controlling zone stability. After leaching, the vertical stress in the dissolved zone is reduced to approximately 3.25 MPa, compared with 13 MPa in intact pillars. In roof-connected scenarios, roof subsidence is limited to about 7 mm, with corresponding surface settlement of 7.7 mm. In contrast, non-connected conditions result in significantly larger deformations, with roof displacement reaching 37.7 mm and surface subsidence of 34.5 mm. These findings demonstrate that roof-connected leached material can provide effective structural support and maintain overall stability, whereas non-connected configurations pose a higher risk of instability. The study offers valuable insights for the safe and sustainable design of solution mining operations in evaporite deposits.