Slashchovа O.A. Water effect on the rocks and mine roadways stability

Geoteh. meh. 2019, 148, 144-152

https://doi.org/10.1051/e3sconf/201910900092

WATER EFFECT ON THE ROCKS AND MINE ROADWAYS STABILITY

1Slashchovа O.A.

1Institute of Geotechnical Mechanics named by N. Poljakov NAS of Ukraine

UDC 622.831.31:622.2:622.112.3                   

Language: English

Abstract. The article is devoted to solving of a live scientific problem of improving methods for predicting stability of mine roadways under mining-and-geological conditions of the rock watering. Research methods: analysis of experimental data on assessing state of water-saturated rock massif; statistical processing of laboratory research results on the strength properties of rock samples; mathematical modeling of the rock massif stress-strain state by the finite element method; mine studies of deformations of water-saturated rocks. Specific effect of water on the rock strength properties was investigated. The generalized correlation dependences of the strength reduction of sandstones, mudstones and siltstones at their saturation with water relatively to their initial strength in natural state were obtained. By method of mathematical modeling, regularity of changes in the stress-strain state of the rock massif depending on rate of preparatory roadway watering were established and confirmed by the mine observations. The correlations were proposed for calculating probable water inflows into the mine roadways basing on the assessment of volume of broken elements in the geomechanical model, parameters of open porosity and fracturing. Nature of deformation of water-saturated rocks in the roof, walls and floor of the mine roadway was determined. It is established that intense deformations starts in the drift walls and manifest themselves in the form of weak rock slips in the coal seam roof and floor. The most dangerous areas are the upper lateral corners of the mine roadway, which are prone to falls under the effect of water, when the roof bolting system loses its bearing capacity. Such manifestations of rock pressure are reliably predicted by analytical method and are verified by data of mine experiments, making it possible to undertake in advance additional measures for proper supporting the mine roadways. It is stated that implementation of a set of measures aimed at reducing water flows into the mine roadway improves its stability due to the smaller size of inelastic deformation zones in the walls and roof of the mine roadway in the stationary abutment-pressure zone, reduced contours of the mine roadway deformation, and decreased rate of horizontal and vertical convergence.

Keywords: stability of mine roadways, water-saturated rocks, rock massif stress-strain state, mathematical modeling, finite element method.

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About the author

Slashchovа Olena Anatoliyivna, Candidate of Technical Sciences (Ph.D), Senior Researcher, Senior Researcher in Department of Mineral Mining at Great Depths, Institute of Geotechnical Mechanics named by N. Poljakov NAS of Ukraine (IGTM, NASU), Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.