1results about How to "Subsidence control" patented technology

This invention relates to the field of coal mining subsidence control, specifically a method for controlling subsidence through chemical modification and expansion of the floor strata. The method includes: determining the extent of the floor failure zone below the coal seam; selecting a certain thickness of strata below the failure zone as an isolation and protection zone; establishing a chemically modified expansion zone below the isolation and protection zone; selecting an expansion chemical agent based on the mineral composition of the strata in the chemically modified expansion zone; constructing directional boreholes in the working face roadway, with the horizontal section of the directional boreholes constructed within the chemically modified expansion zone, and the directional boreholes being constructed in the direction of the cut-out in the working face advancement direction; fracturing the chemically modified expansion zone through the directional boreholes; and injecting the chemical agent into the chemically modified expansion zone through directional grouting boreholes after the working face has passed the horizontal section of the directional boreholes but before reaching the borehole opening. This invention chemically modifies the floor strata to induce expansion, thereby lifting the floor strata to support the goaf, thus reducing the subsidence of the overlying strata and controlling surface subsidence.