Quantitative Evaluation On Geological Structures Of 13-1 Coal In The West Area Of Liuzhuang Mine

The No.13-1 coal seam in west area of Liuzhuang coal mine in Huainan was taken as a research object,and the quantitative method was used to analyze geologic structural characteristics of the coal seam and the fuzzy comprehensive evaluation method was adopted to evaluate its geological structure condition.It is helpful to predict the geological structure complexity of the unmined blocks in this area,and it can provide theoretical basis for safe mining of 13-1 coal seam and prevention of coal and gas outburst.The main research results are as follows:(1)The study area is mainly fractured and fold undeveloped.The two groups are mainly affected,one group is NE direction,which most of them are normal fault;the other is NWW direction,and most of them are reverse faults.(2)The development law and output state of faults were discussed from the aspects of coefficient of plane deformation,fault density,intensity and fractal dimension value.The high value of plane deformation coefficient is mainly distributed in the western area between F12 and F14,which is greater than 0.28;the low value is distributed in the central part,and which is less than 0.2 on the west side of the F22.The gradient of plane deformation coefficient is totally changed along East and West.Fault density high concentrated in the southwest,nearly F1 and its branch faults which is greater than 8,and the lower is located in the southeast of the southern tip of F25 which is less than 2;the southern and northern parts of the contour gradient variation is not consistent,the former is near South to north,the latter is near from east to west.The fault intensity is also located in the position of F1 and its branches which is more than 0.1,the lower in the central part and north area is generally less than 0.05.The distribution of fractal dimension value is high in the southeast and central part of the study area,reaching 1.4,and the rest areas are between 1 and 1.2.The value of fractal dimension mainly concentrated in 1.05?1.50,among which 1.25?1.30 was the most,reaching 12.84%.(3)By using the fuzzy comprehensive evaluation method,the geological structural condition of 13-1 coal mining was comprehensively evaluated.The research shows simple to moderate structure area accounted for 42.4%,mainly distributed in the south of the study area,on the east side of F1;medium to complex degree accounted for 57.6%of the total,mainly distributed in the area of the north to middle;extremely complex zone accounted for 30.3%,distributed in two areas,one is on the west side of F25 and north side of the 13-1 coal line;another is between area of F14 and F12,namely the 4th West block.Complex blocks are located in the middle of the study area,accounting for 27.3%.It was considered that the structural conditions in the study area are more complex and complex.However,the geological structural conditions are also characterized by blocks.Generally,the north is more complex than the central and southern parts,and the west is more complex than the eastern and central parts.