Study On Rational Section Coal Pillar Size Of Fully-mechanized Top Coal Caving Mining Face In Extra Thick And Hard Seam

Coal is China’s main energy, reserves of thick and extra thick seam account for more than46%of the total coal, in order to improve the recovery rate of fully-mechanized caving mining, the study presented the surface two-Lane layout system of small coal pillar for extremely thick coal seam mining。 due to the impact of dynamic pressure, coal pillar destroy the law of fully-mechanized caving face is extremely complex, and encounter great challenges for roadways supporting, Carry out this research in order to reduce the coal mining loss, improve economic efficiency, and ensure that the mine production safety。coal seam thickness is more than8m for Shuiliandong coal mine, coal consistency coefficient is3.1-3.9/3.5, gas emission is23.3m3/min, Secondary spontaneous combustion of coal seam, extra-thick and hard seam during top coal caving based on fire ignition and high gas。 thesis based on the structure of the overlying strata and the law of motion of fully-mechanized caving face along the empty crossheading, the lateral strata pressure manifestation of entity coal along next goaf for3801fully-mechanized face of Shuiliandong coal mine observed twice by online system. The results as follows:(1)this paper obtained the manifestation feature of overburden strata movement in roadway of neighbouring goaf、supporting force and lateral abutment pressure, revealed lateral periodic weighting length is equal to strike periodic weighting length, established the lateral overburden structure model of main roof rock-beam structure based on he stability of roadway roofs、upper immediate roof、the stratum-rock structure of upper immediate roof(located in the upper palts of the winning16-24m).(2)this paper established press model of the partition wall in roadway roofs, obtained Stress-strain relationship of gangued filling body combined with experiment and obtained bearing behavior on the partition wall of roadway roofs to adapt to overburden strata movement by calculation.(3) according to the characteristic of advanced supporting force and lateral strata pressure manifestation feature, this paper ensured the leading role of overburden movement on strata behaviors, it provide basis of measurement to research the theory on strata pressure manifestation controled by strata movement The result applied in3802haulage roadway, the width with coal pillar of No.3801face is8m, reduce22m than before, coal pillars size in fully-mechanized face during stop mining period outside advanced concentration pressure, determined coal pillars size is25m, reduce25m than before, so obtained the expected effect, this paper provided reference value for research on feature and application of ground pressure in similar conditions.