The fractal coefficient of undergound workings shape


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In the process of tunneling the mine workings with the help of drilling and blasting operations, the quality of delineation possesses great significance, i.e. obtaining the section which is maximum designated to the designed outline of the working. The quantitative measure of the degree of the outline curvedness of the working is its fractal size. Particularly, it determines the size of the working section perimeter in mining. In this connection in order to quantitatively estimate the outline deviation from the designed one, the outline blasting quality criterion in the shape of the fractal coefficient of the working shape is suggested. It represents the relation of the working conform representation section area to its perimeter: under the constant working section area, the worth the quality of the delineation is, i.e. the bigger the perimeter is, the smaller the fractal coefficient of the shape is. The surface heterogeneity of the working leads to the increase in the concentration of stresses in its outline. Consequently, fractal coefficient of the shape can serve as the estimation of the coefficient of the stresses concentration. In order to study the given problem, the measurements of the sections of 32 workings in Severouralsk bauxite mines have been fulfilled. The correlation analysis of the results has shown the reliable relation of the fractal coefficient of the shape of workings with the coefficient of the stresses concentration in its outline. The results acquired make it possible to estimate the quality of drilling and blasting operations and the stability of rocks in the working.

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Библиографический список/References

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