Study On The Characteristics Of In-situ Stress Field In Panxie Mining Area

The Huainan coalfield is located in the southern margin of the North China plate.The tile fan structure is located in the north-south side of the coal field with a compound syncline structure in the interior.The main tectonic trace is a hedge tectonic basin near the east-west direction.The thrust nappe from south to north constitutes the nappe structure of two wings hedging in Huainan coalfield.Huainan mining area has entered deep mining stage as a whole,for example,the first level of Dingji mine in Panxie mining area has reached-860 m,and the buried depth of extended horizontal coal seam roadway in Pan-3 Mine has reached less than 800 m.With the increasing mining depth in mining area,the in-situ stress plays a more important role in the layout of roadway and the stability of surrounding rock,which is mainly manifested in the increase of in-situ stress and the rapid deformation of roadway after mining.The deformation range and deformation amount of surrounding rock increase.Taking Panxie mining area as the research object,this paper systematically collects relevant data of geological structure and in-situ stress in Panxie mining area.Twelve measuring points are set up in five mines of Pan-Yi,Pan-er,Pan-San,Pan-bei and Ding-Ji,and the in-situ stress is measured by means of stress relief method.Based on the analysis of the in-situ stress data,the inversion simulation of the in-situ stress field in Pan-Xie mining area is carried out by using numerical method,and the distribution rule of the in-situ stress in Pan-Xie mining area is studied.The following conclusions have been reached:(1)The in-situ stress field in Panxie mining area is dominated by horizontal stress,and most of them are structural stresses in the deep part of the study area,and the tectonic stresses are typical.(2)The linear correlation of principal stresses with depth is found in Panzer mining area,and the correlation of vertical stresses is the strongest.(3)The in-situ stress field in Panxie mining area is dominated by horizontal tectonic stress,and the influence of tectonic stress is greater than that of gravity of rock mass.Fig.[60]table[27]reference[50].