Improvement and Optimization of Grouting Drilling in Overlying Rock Separation Layers
One of the core technologies of overlying rock separa-tion grouting engineering is the selection of hole type and target key layer,hole structure,and prevention of drilling deformation and damage caused by overlying rock migration after mining.We have sorted,analyzed,compared,and summarized the previous grouting boreholes,identified the shortcomings in the project,and continuously improved and optimized them in subsequent construc-tion.Practice has proven that the combination of straight and direc-tional hole layout,as well as the multi-objective key layer compos-ite grouting of single hole and single separation layer,and adjacent(row)hole separation layer,are the key to the success of the proj-ect.The hole-structure should adopt a three-opening design,and the diameter of the hole should match the maximum daily grouting volume and grouting system.The first and last directional holes de-signed using a design method to prevent the failure of the first row of grouting holes in the separation layer and the ultra-deep penetra-tion of the casing into the bedrock are effective measures to pre-vent the failure of grouting holes on the side of the stopping min-ing line and the cutting hole.The inspection hole can be arranged in the same hole as the grouting hole,with one hole for dual use,achieving maximum resource utilization.
hole structuresingle hole multi-layer groutingsingle hole and single separation layer groutingcomposite grouting of adjacent(row)hole separation layerdirectional holeoverall matching
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