2results about How to "Subsidence control" patented technology

The invention belongs to the technical field of mine ground pressure and rock stratum control, and discloses a partial filling rock burst prevention and control method for a full-height goaf of a coal seam above 8 m. The rock stratum position of each hard rock stratum is calculated through a key stratum theory, and the caving height and the limit caving distance of each hard rock stratum are obtained through theoretical calculation; determining the position of a main key layer; and data are introduced to judge whether the key layer conforms to the S-R instability theory or not, the maximum separation space below the main key layer is calculated, and the filling rate and the filling height are determined. According to the method, a goaf part filling method is adopted, the goaf part filling method is coupled with broken and expanded rocks after roof caving, the effect that overlying strata movement is converted from full mining to insufficient mining is achieved, the effect of controlling surface subsidence is achieved by controlling the caving form of a main key layer, large mining height is converted into equivalent small mining height through the method, and the mining efficiency is improved. Filling cost is reduced, and wide application of filling and scour prevention after mining of a coal seam with the thickness of 8 m or above is achieved.

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.