KUCHIN Alexandr & BRUI Anna
To develop a method for determining the increase in stress above advancing longwall face in conditions of Western Donbas mines
The investigation was carried out with application of mine surveying instrumental observations in boreholes and on the Earth's surface.
During extraction of coal seams the area of high rock pressure is formed around the boundary of the gob, which spreads into the roof and the floor of the seam. The distance at the selvedge of the extracted seam where the high rock pressure manifests is called the width of abutment pressure zone and is denoted by l. The value of l depends on the depth of mining and the extraction height of mined seam and is the main initial parameter for designing of high rock pressure zones. The existing methods of l determination give a variation in the prediction of this value up to 100% for the same conditions. The methods for assessing the quantitative parameters of the rock pressure increasing at the selvedge of the extracted seam have not been proposed yet. In this paper, the objective laws of distribution of rock pressure incremental values are considered on the results of mine surveying instrumental observations in boreholes and on the Earth's surface. A method for determining the increment ratio of stress in rock mass above the advancing longwall face in conditions of the Western Donbas mines is proposed and is confirmed by other investigations.
Keywords: subsidence, abutment pressure, strain, rock, undermining, benchmark, borehole extensometer.