Technology of Coal Pillar Mining Face Passing Through Used Gateway

According to the surrounding rock difficult contral problem of the used gateway when the coal pillar mining face was passing through the used gateway, a mechanics model of the main roof in the used gateway was established for the coal pillar mining face.When the width of the used gateway was increased, the support resistance required for the used gateway would be increased and there was a liner relationship between the support resistance of the used gateway and the thickness 0 f the main roof.The higher thickness of the main roof, the support resistance required by the used gateway would be higher.When the support resistance of the support was increased, the support resistance of the used gateway would be in liner reduced tendency.Based on the whole used gateway of the coal mining face divided into thr ee concentrated zones of the used gateway, the support technology of the mining gateway and the surrounding rock stable control technology when the coal mining fac e was passing through 4 used gateways in No.3 used gateway zone were studied.The top coal caving control when the coal mining face passing through the used gate way, advance reinforced support of the two gateways, roof control of the coal mining face and other safety protection measures were set up to ensure the safety mining operation of the coal pillar mining face.