| With the increasing complexity of coal mining geological conditions and the development trend of mining depth to vertical depth,the problem of mine gas is becoming more and more serious,especially coal and gas outburst phenomena cause casualties,destruction of mine will be more severe.A large number of actual observation data and research results show that gas outburst has obvious zoning and zonation,and geological structure is the dominant geological factor to control the prominent subdivision zone.However,the understanding of the complexity of geological structure and its relationship with gas outburst is still at the stage of qualitative analysis and empirical description,lacking systematic analysis and quantitative description.Based on the quantitative study of geological structure by using fractal theory to the coal and gas outburst control action as the research subject,discusses the field 7,8 and 10 main working bed gas geology rule,as well as using the fractal theory and quantitative research methods of fracture and fold structure complex;Study the variation characteristics of construction of the main working bed coal thickness,finally USES the multiple parameters of the gray fuzzy comprehensive evaluation method has carried on the quantitative evaluation of gas hazard,obtained the conclusion of the following aspects:(1)By computer simulation,it is concluded that the sensitive factors that affect the fractal dimension are the number of faults and the length of faults.It provides a preliminary theoretical basis for studying the mechanism of geological structure complexity by fractal means.(2)A statistical method for the fractal dimension of the minefield fracture and fold is put forward,and the fractal dimension contour map of the fracture,folds and coal thickness changes in the well field is made.Generally speaking,the structural complexity of the three coal seams is relatively high.The overall characteristics of their geological structure are closely related to the distribution and development degree of the main faults in the coal field.(3)The fractal dimension statistics method is proposed to express the complexity of coal thickness variation,and the complexity of coal thickness change is studied quantitatively.At the same time,it also shows the accuracy of the statistical method for the fractal dimension of coal thickness and the feasibility of using fractal dimension to characterize the change of coal thickness.The distribution characteristics of coal are analyzed by logging curve interpretation of coal structure characteristics.(4)Using gas content,fracture,folds,thickness of coal seam,thickness of coal and thickness of structural coal and other factors,the grey fuzzy comprehensive evaluation method is applied to quantitatively evaluate the risk of gas outburst in 7,8 and 10 coal seam.The 7 coal seam safety area has a small distribution area,a part of which is distributed in the shallow area of the southeast of the well field,and the safety area is in the 10 East 2,12-3 and 13 East 2 holes.Most of the most dangerous areas are located in the deep area between the 7-8 line of exploration line and the 9 line of exploration line.Besides,there are also prominent risks in the shallow part of the southeast and southwest part of the mine field.The rest of the region is from the danger zone to the threat area,and the threat area occupies most of the area of the well.8 coal seam 7 line to the 8 line of the shallow area,the 8 line to the 10 line of most areas are dangerous areas.The prominent danger zone of the 8 coal seam is larger than that of the 7 coal seam,and it is also changed from the threat area to the dangerous area at the larger faults of F24 and F25 in the Western well field.10 coal seam gas dangerous area is obviously reduced.Only in the eastern part of the mine field,the central part and the western part are dangerous areas,and the rest are threatening areas and safety zones. |
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