Study On Mining Technology And Control Of Broken Coal And Rock For Floor Undulating Section At Mechanized Caving Working Face

Fluctuations of seam floor folds affect the normal production of the working face,and the coal and rock at the interface of coal and rock are broken and easy to roof fall.This essay is base on the undulating conditions of the floor slabs in the 80117 working face of Xinjing Coal Mine,establish a three-dimensional model of the geological structure of the working face,analyzes the stability of the working surface equipment,the roof movement law and the impact on the resource recovery rate under different mining trajectory conditions,and determines the mining technology that minimizes cutting the floor rock under the conditions of ensuring equipment stability and safe production conditions.Using Surfer software to create three-dimensional numerical model,the undulation characteristics of the coal seam floor of the 80117 working face were analyzed and analyzed,which provide a basis for the on-site working face trend and tendency process adjustment and parameter determination.Through the analysis of the mining technology and equipment stability of the fully mechanize caving face in Xinjing Coal Mine,the tilting angle and the shearer’s cutting parameters under the condition that the working face is pushed to the floor undulation are determined.The mining angle is in the range of 10 °-16 °.When crossing the inclined groove,the tilting angle is 16 °.Through field practice,it is find that under the combined effects of mining stress and tectonic stress,the piece and roof falling of the coal and rock junctions at the working face are serious,which is the main factor affecting the safe production of the working face.The experiment results show that the strength of the consolidated body is enhanced to a certain extent under the effect of grouting and strengthening of the broken coal rock mass.Through UDEC numerical calculation and analysis,the grout diffusion law and consolidation effect under the condition of grouting reinforcement were obtained,which provided a theoretical basis for determining the grouting parameters on site.On the site,by adjust the cut trajectory of the working face and the angle of the top and bottom mining,the amount of rock cut by the shearer has been greatly reduced,and the advancement of grouting in the broken coal rock body has effectively maintained the stability of the coal rock in the stope The safety and normal advancement of the working face are guaranteed.The pre-split blasting method is used in the harder local area of the floor,which greatly reduces the load of the shearer.The project research has achieved good technical results and benefits.This paper has 44 pictures,4 tables and 108 references.