| As an important basic energy of China, coal plays an important strategic role in the national economy. With the development of science and technology, coal mining technology continues to progress, and mechanization and automation of coal mine production continues to improve, so ensuring mine safety and efficiently has become the focus of our attention, Coal mine accidents occur frequently, especially roof accidents occurred most frequently. Safety assessment of roof accidents can point the way for preventive measures of roof accident, and reduce the probability of the roof accident in order to protect the coal mine production activities proceed smoothly.Through collecting and consulting related literature data, the paper summarizes the research status of safety evaluation theory and find the reason and regularity of coal mine roof accident by using fault tree assessment methods to analyze risk factors inducing roof accident, in order to find out the most dangerous factors; On the basis of it, orthogonal design and principal component analysis methods are applied to analyze factors affecting the stability of roof, conclude gob roof stability, coal face roof stability and stope roof stability, by using Flac3 D numerical simulation software and SPSS software. In this paper, main conclusions are as follows:Through the analysis of roof accident disaster mechanism and the roof accident cases in our country, risk factors of roof accident can be divided into natural factors, technical factors, human factors and management factors. The fault tree model of roof accidents was established. The basic events and occurrence way were obtained by the qualitative analysis of fault tree.The principal component analysis, based on orthogonal design, not only simplifies the test plan, also considering the interaction between various influencing factors, and the simplified multi-dimensional variables.Evaluation of gob roof stability, coal face roof stability and stope roof stability is a linear relationship between different influence factors and the roof stability, the quantitative influence degree of various factors on the roof stability and the sensitivity of the influencing factors for the roof stability in sort. The influencing factors contain mining height, thickness of the roof, depth of burial, face advanced distance and roof lithological. Compared with the range analysis, the principal component analysis, based on orthogonal design, is more accurate and scientific. The results show that this method is feasible and reliable, can be applied widely in roof stability evaluation. |
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