An appraisal of mathematical models to predict water inflows into underground coal workings

The paper describes various analytical and numerical models which have been used to predict the quantities of water flowing into underground mines. Analytical models of flow into wells are discussed briefly and their limitations when applied to mine water flow are listed. Numerical models designed specifically for underground mines are examined in detail under the three categories of water resource models, mine water models and methane and water models. The extent to which the available numerical models are applicable to British longwall coal mining operations is considered and the need for further work is identified.     

Design considerations for mine workings under accumulations of water

The study outlines the effects of surface and underground subsidence patterns on the spatial distribution of in-situ permeability and its effects on groundwater inflow. The behaviour of strata surrounding a longwall face where limited knowledge exists has been outlined. The effects of mining subsidence on the surface flow pattern have been described with the remedial solutions. The mechanism of formation of sinkholes in certain chemical rockmass has been described. Factors affecting mine water inflow have been described in detail with the aid of a simplified conceptual model and case studies. Practical examples of undersea workings and those under a large accumulation of water are given, both in the United Kingdom and worldwide.     

Numerical simulation of caved goaf behaviour in longwall workings

Modifications of the Chamber of Mines formula, which defines stress-strain behaviour of fills, were attempted to suit caved goaf material behaviour. The constants of this formula were varied to run 2-D displacement discontinuity type boundary element models. This variation was carried out by trial and error to improve the stress distribution over the goaf as per available field experience. It was seen that the constants in the formula must be varied across the goaf in order to obtain realistic normal stress distributions. Final values of these constants are recommended for different cover depths and seam thicknesses.     

Characteristics of electromagnetic noise in mine workings

Militarized Mine Rescue Unit, Sverdlovsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 98–102, November–December, 1989.     

Determination of the turbulent diffusion and heat-conduction coefficients in mine workings

Makeev Scientific Research Institute. Translated from Fiziko-tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 5, pp. 90–92, September–October, 1990.