(1) drilling field positioning principle
(1) drill spacing should be matching with ability to drill.
(2) the drill field location should be chosen in construction of drilling to ensure that the effective positioning in the Angle of roof fracture zone on the working plane location,and have enough length of drainage borehole,generally in return air lane inside.
(3) avoid drilling field layout in rock fracture zone.
Games (2) the drill construction parameters of the drilling depth of the net more than 6 m,local ventilation measures should be taken to prevent the gas accumulation.Drill site specific construction parameters is:under the wind lane first help to the coal seam roof with 30 ° climbing construction length x width x height = 6.0 m x 2.5 m x 2.0 m of the roadway,and flatten the construction length x width x height = 4.0 m x 3.5 m x 3.5 m lie the drilling platform.
純屬自己翻譯的,