Application Research On Crossing Fault Technique Of 1006 Working Face In Fucun Coal Mine

Hard fault is a common geological structure in the process of working face advance.When the working face crosses the fault,it is mainly confronted with the controllability of fault rock and the stability of surrounding rock of roadway in fault stage.The fault structure of 1006 working face of upper coal seam 3 in Fucun Coal Mine is developed,which has been greatly influenced by the the igneous wall fault structure obliqued to the working face,resulting in obvious changes in coal seam occurrence and local coal thickness.When the working face is close to the fault area,the overburden activities have a wide range of influence,the roof movement is complex,and the roadway pressure in the fault area is intense.This thesis takes the fault structure of 1006 working face of upper coal seam 3 in Fucun Coal Mine as the research object,comprehensively uses the field investigation,theoretical analysis,numerical simulation and other methods to study the characteristics of the crack initiation and expansion of the hard igneous rock wall fault,the parameters of the deep hole blasting of the working face across the hard fault,and the supporting parameters of the roadway in the working face across the fault area.The main conclusions are as follows:(1)The geological conditions of the hard fault in the 1006 working face of upper coal seam 3 are analyzed,a model of the crack initiation and propagation of the hard fault under deep-hole blasting is established,the blastability of the hard fault rock and the crack propagation law under the explosion load are studied,and the surrounding rock failure zone of the drilling blasting in the working face of upper coal seam 3 and the characteristics of shock wave combined with explosive gas breaking rock are discussed.(2)The rock breaking mechanism of the combination of explosion wave and explosive gas in the hole was clarified,the wave load transfer law and the evolution process of explosive gas expansion under the single/double hole initiation condition of the model test block were obtained,and the law that the simultaneous initiation condition of the double holes is conducive to the surrounding rock fracture penetration and directional fracture induction between the holes was revealed.According to the oblique geometric relation between igneous rock wall fault and working face,the parameters of pre-split blasting drilling bedding in two roadway of working face are determined,including hole depth,aperture,hole spacing,etc.(3)The influence range of the roadway affected by the hard igneous wall fault is determined,the stress distribution law of the spaced coal pillar is obtained,and the surrounding rock supporting parameters of the roadway affected by the fault are designed.It is considered that the original bolt support cannot meet the requirements,and the roadway across the fault has serious deformation,and the reinforcement supporting measures must be taken.When the deformation of rock mass around the roadway is controlled,the action exerted by bolt and cable is concentrated within the support range of the cable.The stress of the shallow part of the roadway increases obviously,while the stress change of the deep part is small.The row distance between the cable is determined to be 1.2×1.5 m,and the length of the cable is 6 m,which guarantees the safety of personnel and equipment on the working face.There are 64 figures,8 tables and 75 references in this thesis.