FRACTAL THEORY AND IT’S APPLICATIONS ON ROCK DRILLABILITY FORECASTING

The basic conception of fractal geometry and fractal dimension is introduced,and the methods for determining four kinds of values of fractal dimensions are defined.The fractal character of rock-crashing and fractal measurement methods of rock-crashing shiver are explained.Abnormity of rock-crashing can be described commendably by fractal geometry.Intensity,rigidity,drillability of rock and micro-structure,pore structure,crashing manner of rock are related to fractal dimension.Broken fragment distribution function is determined based on laboratory experiment.Broken fractal dimension of rock is calculated.Experiment data is regressed by five mathematics models such as beeline,power function,logarithm,exponential function and multinomial.As a result,the aggregate index of beeline regression equation is the biggest.The correlation parameter is more than 0.96.There is inherent relation between rock rigidity,intensity,drillability and rock fractal dimension.Furthermore,the applications of fractal dimension on rock drillability Forecasting is discussed preliminarily.