Structural Complexity Evaluation And Tectonic Stress Simulation Of Xinjing Mine In Yangquan Area

The research area is located in the west of Yangquan mining area.In this thesis,on the basis of integrating the geological data of Xinjing mine,the field structure observation is carried out,and the structural development,distribution,combination and superposition of Xinjing mine are revealed.Based on fractal dimension of fault and structural curvature,a comprehensive evaluation method of structural complexity is established,and the structural complexity of different parts of Xinjing mining area is quantitatively analyzed.Combined with the numerical simulation of tectonic stress field,the distribution characteristics and concentration law of present tectonic stress in the study area are revealed.Combined with the drainage and production data of coalbed methane Wells in the study area,the influence of tectonic action on the productivity of coalbed methane Wells is revealed.Field geological survey was carried out in the study area,28 effective observation points were recorded,and 936 joints were measured and counted.The results show that the structure of the study area is relatively simple,but the joints are well developed and mainly shear joints.The joint strike is mainly NEE trending to the north,followed by NE trending to the north and North-north west trending to the north,which indicates that Xinjing ore has developed multiple stages and different directions of tectonic action.The types of superimposed folds in the study area mainly include vault structure,basin structure and saddle structure.The plane combination forms of fold include broom combination,fusiforn combination,diagonal combination,ladder combination,palisade combination and grid form combination.The structural complexity of the study area is characterized by the similarity dimension of fault fractal dimension.The results show that the central and western regions of No.3 coal seam are moderately complex fault structures,and the central and eastern regions are complex fault structures.The middle area of No.15 coal seam is a medium fault structure area,and the south area is a complex fault structure area.The structural curvature distribution of No.3 and No.3 coal seams in the study area was similar,both of which are alternately positive and negative in the east-west direction.The contour lines are sparse in the west,densest in the middle and less dense in the east.It is considered that the structural curvature of coal seam No.3 and No.15 is mainly controlled by syncline,and anticline has superimposed control on the structure in the area.Combined with the distribution of fault fractal dimension and structural curvature,the structure of Xinjingkuang coal seam No.3 and No.15 can be divided into simple complex structure area,medium complex structure area and complex structure area.The numerical simulation of tectonic stress field of No.3 and No.15 coal seams in Xinjing Mine is carried out.The simulation results show that the maximum stress and minimum stress of No.3 and No.15 coal seam are distributed in a strip from west to east.The high maximum stress is distributed near the synclinal core,while the high minimum stress is concentrated near the anticlinal core.Both of them increase with the increase of the absolute value of the structural curvature,and the stress state has a good correspondence with the structural curvature.The data of 22 CBM Wells in the study area were collected,and the relationship between the structure and the productivity of coalbed methane Wells was studied by combining the fractal dimension of fault,tectonic curvature and the distribution of tectonic stress field.