Overburden rock permeability variation and vertical zoning characteristics under the influence of coal mining

In-situ packer tests in underground borehole and related theoretical calculation were conducted to study the overburden rock permeability variation and vertical zoning characteristics before and after coal mining. Working face X in Bangladesh Barapukuria coal mine was chosen as the test area. The research results show that overburden rock permeability changes significantly and has obvious vertical zoning characteristics after coal mining. From the top to the bottom of fracture zone, rock permeability increases gradually and can be subdivided to weak, medium and strong permeability zones. This conclusion has important guiding significance for hydrogeological parameters identification and water inflow forecast in coal mining area.