The relationship between lowering the Earth's surface and bearing pressure above the advancing longwall face

Abstract

This work aims to develop a method for determining the increase in stresses above an advancing longwall face of Western Donbas mines. The paper presents a solution to the problem. It is based on the analysis of geodetic instrumental observations of the earth's surface lowering and rock mass deformation above the advancing longwall face. Length and propagation in the roof and floor of the extracted seam are the main geometrical parameters of the zone of high rock pressure. Currently, the quantitative parameters of this zone are not considered. And its length under the conditions of Western Donbas is determined with an accuracy of 50%. Thus, research in this direction is relevant. The experimental basis for the research includes the results of observations performed at two vertical borehole extensometers and the results of data processing obtained at more than 30 observation stations on the Earth's surface. Thus, the research specified the geometrical parameters of the zone of high rock pressure and the nature of the vertical stress distribution within this zone. The paper introduces a method to determine a coefficient of stress increase above the advancing longwall face of Western Donbas mines. We also established the empirical coefficients of the vertical stress distribution function within the abutment pressure zone. There is a relationship between the lowering of the earth's surface and the values of the stress increase in the borehole edge part. The reliability of the obtained results is confirmed by geophysical studies in Western Donbas, as well as by the results of field observations.