Research and Practice on Water Damage Governance Technology for Thin Layer Limestone in Chengjiao Coal Mine
To solve the problem of poor conventional grouting governance effect for downhole water damage in Chengjiao Coal Mine,the regional advanced governance technology formed by ground horizontal directional drilling technology provides a new technical approach for governing water damage in the floor limestone of this coal mine.After research and demonstration,the L10 limestone in the upper section of the Taiyuan Formation is selected as the purpose layer for governance in the 14th auxiliary mining area surface regional governance of this coal mine to prevent floor water damage.By constructing 35 horizontal branch holes in three ground hole groups(D1,D2,D3 hole),the geological,hydrogeological,and hidden water bearing(conductive)structures of the L10 limestone in the upper section of the Taiyuan Formation in the governance area are explored,and the purpose layer is transformed into an effective waterproof layer through high-pressure grouting governance;The downhole verification drilling water inflow of construction is less than 10 m3/h,and the governance effect is good;After governance,the maximum water inrush coefficient of the F21405 working face in the 14th auxiliary mining area is calculated to be 0.044 MPa/m,which meets the standard of a safety value of no more than 0.06 MPa/m for water inrush coefficient.There is no threat of water inrush and it can be safely mined.
Taiyuan Formationthin layer limestonewater hazard prevention and controlregional governance
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