Effect of Geothermal Gradient on Stress State of Rock Mass in Coal Mining
V. M. Seryakov
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Coal deposits, stratified rock mass, rock temperature, stress state, mathematical modeling, mechanical and thermophysical properties, multi-seam mining, mining advance
Abstract
Using the mathematical modeling, the author performs the stress-strain analysis of stratified rock mass in the course of mining of close-spaced coal seams with regard to linear change in temperature field with depth. The problem is considered in an incoherent quasistatic formulation: first the temperature field is determined and then the stress-strain assessment is made using the Duhamel-Neumann law. The problem solving used the finite element method. It was assumed that the rock mass layers occur in complete contact. The initial stress state was found on the basis of Dinnik’s hypothesis. The features of the initial stress state, which influence stress redistribution during coal mining, are determined. The variants of close-spaced coal seam mining are discussed, and the related stress state peculiarities are highlighted as compared with mining with no regard to the temperature gradient.
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