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Abstract To ensure the stability and working of the advance supported roadway on gob side at the extra-thick seam zone during the mining process in Datong mine，a combined method of theoretical analysis and field measurement was used to obtain the pressure behavior of the forepoling segment of the roadway. The results of the research showed that the depths affected by the stress concentration zone of the coal pillar at mined-out section of Jurassic period were only 50–70 m，not deep enough to affect the occurrence of the strata pressure at the working face of the advance supported roadway in Carboniferous period. The occurrence of the strong strata pressure at the advance supported roadway in Carboniferous period was mainly affected by the abutment pressure due to mining and the high bearing pressure of overhang roof on two sides of the adjacent mined-out area. When the working front passed the boundary pillar of the mined-out area of the overlying coal，the big seam roof structure in Jurassic period was reactivated and tended to be unstable again，which speeded up the occurrence of the strong strata pressure of the roadway approaching the mined-out area. An effective control technology with the orientated high-pressure hydraulic fracturing of roadway roof was proposed and applied to the working front 8105 in the roadway 5105 approaching the mined-out area in Tongxin mine. The technology achieved the high stress transfer in the surrounding rock of roadway and greatly reduced the strong strata pressure of advance supported roadway approaching mined-out area.
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Received: 28 April 2014
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2014, Vol. 33 
