Study On The Overlying Strata Movement Law And Mine Strata Pressure Behavior Of 1026 Isolated Stope In Suntuan Coal Mine

Isolated stope is at the upper and lower sides are mining empty area or one side of the boundary faults, stop production line side goaf mining field. Due to the influence of surrounding mining goaf, isolated stope mine pressure severe appearance, serious damage to the surrounding rock, the island mining field and its surrounding trough stress concentration degree is relatively high, especially the side abutment pressure and along goaf roadway roadway surrounding rock deformation is serious in mining of isolated island, resulting in roadway support difficult, and the stress concentration area of coal and gas outburst and rockburst risk.In this paper,1026 isolated stope of Suntuan coal mine as the engineering background, firstly studying overburden the overall spatial structure of isolated stope in the vertical section and the horizontal level, found that the island of stopeoverburden overall spatial structure are dynamic and unstable, than ordinary rock strata spatial structure influence range, island mining a complex spatial structure of overlying strata are mainly caused by the characteristics of stronger than ordinary stope the strata behavior. Then by using the elastic thin plate of knowledge, the establishment of mechanical model of thin plate on both sides of the mined out isolated stope roof in different stages, get isolated face roof in different phases of the moment, stress and deflection and law. With the method of limit analysis, get the isolated face roof first breaking and cycle breaking step. And then use FLAC3D to 1026 isolated stope three-dimensional model of surrounding rock, mining and mining process simulation of stress, a The evolution characteristics of displacement and plastic zone, and studied the coal pillar in different directions on the stress and displacement evolution characteristics, research:in view of the influence of goaf overlying strata in mining, resulting in 1026 isolated stope in stress concentration zone, strata pressure strong; two coal pillar should force difference and the displacement condition, due to the effect of gravity on the coal pillar, the numerical value of stress and displacement than the coal pillar under small coal pillar under vertical. The maximum stress value was coal pillar under horizontal displacement of 28MPa and 35MPa. were 175mm and 225mm., the maximum value at the end of the 1026 isolated stope of hydraulic support resistance monitoring, deep displacement and two lane roadway surface displacement, the monitoring results show that the distance of immediate roof caving is 19.2m, roof first weighting is 22.54m, periodic roof weighting step by drawing the hydraulic support working resistance frequency distribution histogram of 9.79m., the Show that the 1026 Island mining hydraulic support field of upper and lower efficiency in the practical work is not very high, not to the rated working resistance of support, selection of hydraulic support in central 1026 isolated stope basically meet the production demand, the high frequency region of hydraulic support working resistance distribution in the 15MPa to 25MPa. The wind lane surface displacement monitoring shows that with the decrease of the distance between the observation section and isolated stope, two slope deformation displacement increases, the whole roof and floor displacement of more than two to help, while the three observation section of roof and floor deformation displacement eventually equal displacement peak at around 200mm. By deep displacement observation two lane can be learned, two roadway roof deformation is smaller than the upper part, and separated by 43.8m within the area of stope surrounding rock, when mining is very strong, so the distance of stope and 43.8m when it must be on the Two lane implementation reinforcement support. And also found that with measuring points in the borehole depth increasing, the top floor displacement and two sides of displacement is increasing. The reason is deep measuring points in the elastic zone of roadway surrounding rock, shallow and measuring point in roadway surrounding rock plastic zone, and plastic zone of surrounding rock has been destroyed, so the deformation is small.Therefore, the island of stope in the mining process of roof movement law, to deeper understanding of the mine pressure behavior problems, is no small role to control two roadway and coal pillar deformation, reduce waste of coal, improving management of coal mine.