Characteristics Analysis And Control Technology Research Of Rib Spalling And Roof Falling In Deeply Inclined Working Face Of Xinji No.2 Mine

In the mining of deeply inclined coal seam mining,rib spalling and roof falling are easy to occur in the working face.After forming a large area of rib spalling and roof falling area,it causes a larger area of spalling and roof falling above the area.Based on the engineering background of 211112 working face of Xinji No.2 Coal Mine in Huainan City,this paper studies the Causes and characteristics of spalling roof fall in working face,the instability characteristics of surrounding rock in roof fall area and its influencing factors through theoretical analysis,numerical calculation and industrial test.This paper puts forward the control technology of filling and supporting in largearea falling area of working face,studies and determines the parameters of filling body,and has been successfully applied in the field.The main achievements are as follows:(1)Causes of spalling and roof fall.Low working resistance of working face support and strong rock pressure behavior in the middle and upper part of working face along the dip direction are the main reasons for the spalling of working face.Large depth of spalling area and small strength and thick Ness of direct roof are easy to cause direct roof falling.From the energy point of view,the direct roof falling can increase the deformation energy of coal wall and aggravate the spalling of coal wall.This vicious circle eventually leads to large area spalling and roof falling.(2)The instability characteristics of surrounding rock in the area of spalling and roof fall.Numerical simulation is applied to analyze the influence of rib spalling depth,direct roof strength,direct roof thick Ness and coal seam dip angle on the instability characteristics of surrounding rock in the rib spalling and roof fall area of working face.Combined with the geological conditions of working face,it is proposed that the filling support in the rib spalling and roof fall area of working face is necessary.(3)Filling and supporting technology for spalling roof fall area.Based on the stability of surrounding rock in the roof fall area of working face,the filling support technology is proposed to treat the roof fall area of working face.Combined with the stability characteristics of backfill and surrounding rock in roof fall area under different strength of backfill,the parameters of backfill meeting the support requirements are determined.(4)Field application effect analysis.The filling support scheme of the large dip angle working face is applied in the field,and the working face passes through the falling area safely and quickly.The mine pressure monitoring results show that this technology effectively improves the stability of the surrounding rock of the working face.This paper includes 67 graphs,6 tables and 87 references.