| Based on collecting,collating and analyzing on mine geology material,studies tectonic development features,quantitative evaluation and difference comparison of Nos.3 and 15 coal seams of Xinjing coal mine in deep and reveals tectonic development features and superposition and transformation rules of two coal seams.The formation,evolution and dynamic mechanism of coal mine are discussed by the analysis of regional tectonic evolution.Through the observation of underground coal wall,analysis of tectonic deformation characteristics of coal sample and log interpretation,analyzes macro and micro deformation characteristics of tectonically deformed coal(TDC)and development law of coal seam with different coal structure,discusses the main control geological factors of development and distribution of TDC.The following results and understanding are obtained.(1)Based on the analysis of regional tectonic background,deeply study on the structure development of Xinjing coal mine and its response to regional tectonic evolution,and quantitatively evaluate the complexity of mine structures The coal-bearing strata of Xinjing coal mine mainly experienced three stages of tectonic stress,which NS compression at Indosinian,NWW-SEE compression at Yanshanian,and NNE-SSW compression at Himalayan period.And the tectonic action of Yanshanian is the strongest in the study area.Under the influence of regional tectonic action,Xinjing coal mine formed in the tectonic pattern of NNE-NE to fold as the main body,and has obvious characteristics of multi period and different direction of mutually superposed fold.And the bending structure of No.15 coal seam is relatively developed.The development of fault structure is relatively weak,and there are the main development scale and small drop normal fault and less reverse fault.The faults of No.3 coal seam are mainly NW-trending,followed by NE-trending,while that of other directions are relatively sparse.However,the faults of No.15 coal seam are mainly NW-trending,and the ratio of reverse fault of No.15 coal seam development is higher than that of No.3 coal seam.The intensity of the collapse column of No.15 coal seam,which was significantly affected by NNW-NE trending large wide and gentle anticline,is higher than that of No.3 coal seam.The fold structure of Nos.3 and 15 coal seam is evaluated quantitative evaluation by application trend surface,residual analysis and structural curvature,and the result shows that the overall deformation of No.15 coal seam is stronger than that of No.3 coal seam.The quantitative evaluation of fractal dimension of fault development complexity shows that the fault development of Nos.3 and 15 coal seam is of moderate complexity,but the development of fault of No.3 coal seam is stronger than that of No.15 coal seam.(2)Through the Systemic study of TDC Revealing the characteristics of TDC development and distribution law of coal seam with different coal structures in Xinjing coal mine The study area is mainly composed of structural brittle deformation series by the analysis of macro-and micro deformation characteristics of TDC.The main types of TDC are cataclastic-,schistose-and granulitic coal,with locally developed scaly-and wrinkle coal of brittle-ductile transition-and ductile deformation series.TDC of No.3 development is more common and more types;while subject to mining conditions,the samples collected from No.15 coal seam are mainly cataclastic coal,with locally collected schistose-,granulitic-and scaly coal.With the increase of the deformation of coal from brittle to ductile deformation,the strength of coal mass decreases gradually while the development degree of friction surface and fracture increases gradually.The coal structure is divided into 3 types according to the interpretation of drilling and logging curves: type I includes primary coal and part of cataclastic coal which is weakly deformed,type II includes cataclastic coal which is strongly deformed,schistose-and mortar coal,and type III includes granulitic-,scalyand wrinkle coal.No.3 and 15 coal seams mainly developed weak deformation of type I coal and middle deformation of type II coal,while strong deformation of type III coal is only partially developed and very little full layer output.The TDC development degree of No.15 coal seam is stronger than that of No.3 coal seam.(3)Though the systematic analyze of the factors affecting TDC development It is considered that the fold structure and the fault structure have a key control effect on the deformation of coal body.Systemic analyze the influence of fold structure,fault structure,slate changes of top and bottom and coal seam thickness on the development of TDC.It is concluded that the fold-and fault structure have obvious control effect on coal deformation.Among them,the influence of bending structure on the development of type III coal is obvious.The influence of slate of top and bottom on the development of TDC is weak,while that of roof scouring is obvious.And the reduction and the thin out of coal seam thickness are also beneficial to the development of TDC.The distribution law of No.3 and 15 coal seam is discussed combining with the observation of TDC and underground coal wall and the comprehensive identification of drilling and logging interpretation. |
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