Research on Mine Pressure Evolution and Control Technology of Fully Mechanized Mining Face under Weak Roof Conditions

Aiming at the problem of strong mine pressure behavior in the fully mechanized mining face with weak roof, taking the first mining face of the 2^# coal seam in Taitou Coal Coke, Xiangning Coking Coal, Shanxi Province as the engineering background, through a coupled monitoring mean of "point-line-face", an entropy weight-extensible risk evaluation model is constructed, the working face is divided into three zones: safety, early warning, and danger, and a precise management and control of mine pressure risks is achieved. On this basis, a three in one control technology of "high initial support force bracket support+directional hydraulic fracturing and pressure relief+ultra-high strength anchor cable net surface protection" is proposed. The test shows that after applying this technology, the periodic weighting step distance of the working face is improved by 36%, the peak value of support resistance is reduced by 11%, the monthly advancement progress is improved from 75 m to 98 m, and the annually created economic benefit is 16.4 million yuan. A replicable and promotable technical paradigm for weak roof mine pressure control is ultimately formed.