| Currently, Driving roadway and tunneling working face in impact tendency coal rock, lead to coal rock strenuous vibration failure in ground pressure and cause major accident like “rock burst”“coal and gas outburst” etc. This is serious threat to our country’s coal mine safety production. So on basis of further study on accident cause and realization conditions, deeply studying control theory of accident, To achieve the goal of eliminating the threat of related accidents is a major event in the realization of coal mine safety production in China at present. In this paper, Case analysis, theoretical model, numerical simulation, engineering verification was used to reveal mechanism of rock burst disaster under the condition of hard roof, control methed was proposed, and innovative research results was gained.(1) Rock burst power resourse was bring clarity, it contains compression elastic energy existing in coal and rock around working face and overlying strata(roof and floor)bending elastic energy. Figure out that the greatest bending elastic energy was at maximum moment point, it is not difficult to know that working face rock burst is caused by two kinds of elastic energy. Source of roadway rock burst is to excavate roadway in peak area of supporting pressure. Under the conditons existing “internal stress field”, to excavate roadway and advance working face in “internal stress field” in which overlying strata’s movement has come into stable state, rock burst could effectively avoided.(2) Paper deepened study on rockburst power source stress basis, pointed out stress distribution characteristics of tectonic stress field put forward by tectonic movement, and reveals the condition of original tectonic stress field in the vertical direction of tectonic stress of the earth’s surface can be more than gravity, thus correcting the tectonic stress field in the horizontal stress constant is greater than the vertical stress of traditional knowledge. The paper correctly pointed out that great compression elastic energy exist in remnant tectonic stress field high stress area, to excate roadway and advance working face in this area could possibly evoke the releasing of elastic energy, and rock burst could possibly be caused.(3) Island working face formed by jumping mining was under the action of the coal wall compressive elastic energy and the bending elastic energy of overlying strata. The possibility of the occurrence of rock burst depends on the mining condition. While the isolated island working face is long enough(longer than first breaking step distance of the main roof), the main roof could collapse adequately, there is no risk of shock on the island working face. On the contrary, While the isolated island working face is less than first breaking step distance of the main roof, island working face has the inevitable impact risk. Based on this recognition, the control method of rock burst in the working face is put forward.(4) Composition of technical system of coal pillar mining is described, the development direction and breakthrough focusof coal pillar mining was pointed out, the mechanical model of cutting roof structure is described, the function of cutting roof roadway technology was analyzed. A soft curtain sealing device used for non coal pillar road way by cutting roof and its application method was recearched and deceloped.(5) Engineering verification of roadway by cutting roof was carried out in Halagou Coal Mine, and PU monitoring system based on 110 methods was puts forward innovativly. In the construction process, the surrounding rock of roadway is carefully monitored. Result incicate that roadway by cutting roof technology could cancle coal pillar, no-pillar mining was achieved, ground pressure appearance was relatively weaker, could control occurrence of rock burst. |
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