Application Of Fractal Theory Of Analysis On Accident Of Coal Mine

The production system of coal mine is a very complex nonlinear system. All accidents in coal mine are result from the coupling of many uncertain factors. In this paper, the fractal theory is used to analysis the temporal and spatial distribution of coal mine accidents in China. Specific studies include the fractal characteristic of spatial distribution of all coal mine accidents, roof accidents and gas accidents occurrence from 2001 to 2005 and the R/S analysis of accidents time series from 2003 to 2005.The spatial distribution of all of accidents, roof accidents and gas accidents of coal mine in China show similar between 2001 and 2005 that most of accidents occurrence in these east provinces such as Shanxi, Gansu, Hubei, Hunan, Guizhou and Jiangxi as well as in Xinjiang province of west China. The distribution of the accidents mostly related to the factors including the distribution of coal resources, the level of regional economy and production technology, and the management of safety production.The fractal analysis of spatial distribution of all of accidents, roof accidents and gas accidents of coal mine in China occurrence from 2001 to 2005 indicate that the spatial distribution of accidents show a bifractal relationship with two scaleless range. The average boundary of two scaleless range respectively is 84km, 65.2 km, 69.4 km and the less than the boundary is the first scaleless range and the greater than the boundary is the second scaleless range. The average fractal dimension of the first scaleless range D1 respectively is 0.3683, 0.4995, 0.2568 and the second scaleless range D2 respectively is 1.1125,0.8315,0.6974. The accident spatial distribution of the second scaleless range is more complex than the first scaleless range. And what's more, the spatial distribution of all accidents is more complex than the gas accident and roof accident as well as the spatial distribution of roof accidents is more complex than gas accidents.The R/S analysis of coal mine accidents time series with the interval is a month for roof accident and gas accident from 2003 to 2005 in China show fractal character.The Hurst exponent H for the time series of roof accident and gas accident is 0.8796 and 0.7763 respectively. Both of the H values are larger than 0.5 and which show obviously positive correlation for accident temporal distribution. Therefore, statistics of roof accidents and gas accidents from 2003 to 2005 show a degressive tendency indicate that the future tendency is also degressive.