Study on the Relation between the Gas Emission and Complex Kinetic Process of coal Face

摘要

The relation between the evolvement of in support pressures and gas emission of the coal face during mining excavation was discussed by theoretical analysis and situ measurement. The periodical weighting is a progressive action on a certain range in front of the coal space, from small to large and gradually loading and unloading. The magnitude of support pressure changes continuously in a periodical, but mutate and jump occurs when the periodical weighting comes. And support pressure changes correspondingly, the change of gas emission has a same pattern, i.e, with the supporting pressure increment gas emission is increased in the front of the coal face. The compress ional movement like the piston motion of the roof stratum will push the high concentration gas at the top gob into the coal face, leading to the gas concentration increasing suddenly. The gas is gathered at the gob top behind the hydraulic supporter, along with the increase in height from the floor, the higher the gas concentration. But the gas in the gob nearby the coal face can be blow out by the ventilation with enough energy, so the gas concentration is low in a certain range along the advancing direction.