The Influence of Ground Water Level Rise in Gob of Coal Mines on Ground Surface Deformation on the Example of the Kotlyarevsky Mine

Abstract

Purpose. The study of the influence of mine water rising level of longwalls gob on the activation of deformation processes on the undermined earth’s surface. Methods. In the study was used the method of engineering and graphic analysis for calculating the parameters of the displacement trough according to the normative method. The finite element method that was implemented in the Ansys code was used to carry out studies of the influence of mine water rising level on the deformation of the earth’s surface. The problem is solved in an elastic-plastic setting, taking into account the heterogeneity of rocks. Findings. In accordance with the conditions of the southern part of the mine field, a landslide trough was drawn, and a plan of subsidence isolines was constructed with surface infrastructure objects. Surface objects, the risk of destruction of which increases when the mine water level rises, have been identified. The position of the cut line, which characterizes the most dangerous position, is determined. After the analysis and generalization of the results of the numerical experiment, it was established that the rise of mine water level in the gobs of 1th and 2th southern longwall of the coal seam l1 of Kotlyarevsky mine leads to the activation of landslides on the earth’s surface. At the same time, the vertical subsidence in the displacement trough in the case of flooding (to the full height of the zone of ordered destruction) increases by 22.4%, and the width of the trough increases disproportionately – by 1.3%. This contributes to a significant increase in hazards for surface infrastructure objects due to the increase in slopes and curvatures. Originality consists in establishing of the features of changes in surface displacement in the area of undermined earth’s surface due to the rise of mine water level. Practical implication. The results of the study can be used in the prediction of subsidence and other elements of landslides in the displacement trough, which are activated due to the rise of mine water level. At the same time, the possibility of timely planning and development of a set of measures to protect surface infrastructure objects from the negative impact of undermining is ensured. Keywords: earth’s surface displacement, surface undermine, landslides, displacement trough, rise of mine water level, surface displacement forecast.