Study on collaborative control of “roof-rib” dual pressure relief in gob-side entry driving under superimposed strong mining-induced stresses

Le résumé fourni par la source

Aiming at the control difficulty of large deformation driven by different mechanisms in the solid coal rib and the coal pillar rib of gob-side entry driving under the influence of superimposed strong mining-induced stresses from opposing mining and excavation in thick coal seams, a comprehensive research approach combining theoretical analysis, numerical simulation, physical similarity simulation, and field industrial tests was adopted. The main conclusions are as follows: ①The mechanisms of large deformation driven by different causes were revealed: the "superimposed mining stress-driven type" for the solid coal rib and the “superimposed overlying strata structural rotation-driven type” for the coal pillar rib. Based on this, a “roof-rib” dual pressure relief collaborative control technology was proposed. ②A comprehensive control scheme was formulated, integrating pre-splitting roof cutting on the gob side, internal pressure relief and anchoring synergy in the solid coal rib, and steel shed-cable coupling in the coal pillar rib. Specifically, the roof cutting parameters include a height of 10m, an elevation angle of 90°, and a cutting hole spacing of 0.6m; the large-diameter pressure relief boreholes feature a starting depth of 6m, a length of 4m, a spacing of 3m, and a diameter of 1m. ③The collaborative control scheme must be implemented no later than 30m before the intersection of the opposing mining and driving faces, covering a total implementation length of 80m within the strong superposition zone. ④Numerical simulations demonstrate that the stress concentration degree of the two ribs is significantly reduced by 44.1% after the adoption of this technology. Field strata behavior monitoring indicates that the convergence of the roadway roof-to-floor and the two ribs is reduced by approximately 74% and 77%, respectively, compared with the original scheme. The research results can provide an important reference for the surrounding rock control of other roadways subjected to strong mining-induced stresses.

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