Roof Of Shanzhai Mine Based On Borehole Logging Technology Study On Overburden Structure

With the increase of mining depth,accidents such as roof falling are more and more frequent.The main reason is that the understanding of the geological structure of the roof is not accurate and fast enough.Therefore,how to quickly identify the roof rock structure is the key to solve this problem.The conventional method uses coring to identify the roof rock structure,which has a large amount of work and a high cost,and takes a long time,so it can not provide theoretical basis for roof support in time.In view of this problem,the vibration measurement method while drilling is put forward for the purpose of quickly identifying the roof strata structure,which is of great significance to the production of the mine.Based on the engineering geological conditions of Shanzhai coal mine,this paper makes a series of comparative analysis through the methods of core drilling,peep imaging analysis and vibration measurement while drilling,aiming to establish the unique physical and mechanical logging curve model of Shanzhai coal mine,the main research process is as follows:1)arrange the appropriate measuring points in the typical area of Shanzhai coal mine.Firstly,record the measuring points by drilling and coring,measure the physical and mechanical properties of the samples obtained by drilling and coring,and obtain the different physical and mechanical parameters of various lithology,so as to provide the basis for the later establishment of physical and mechanical model.2)Through the hole wall imaging analysis of the measuring points,the lithology of the roadway roof is analyzed and judged through the drilling peep,and then combined with the previous drilling core,the roadway roof strata can be divided accurately.3)vibration measurement while drilling is carried out at the measuring point.Firstly,the principle of vibration measurement while drilling is analyzed in all aspects,and the three vibration modes of vibration measurement while drilling are explained in detail.The vibration characteristics and formula derivation are analyzed from the mechanical point of view,so as to verify the reliability of vibration measurement at any time in principle.The vibration measuring instrument while drilling is used to measure the previously arranged boreholes and analyze,process and interpret the vibration measuring data.The lithology of the three arrangement points is basically divided.Through the interpretation of energy and spectrum analysis,combined with the previous data and imaging analysis,the vibration measurement is supplemented and finally distinguished4)through the vibration measurement while drilling,combined with the previous borehole logging and imaging analysis,the lithology of the three locations is comprehensively analyzed and interpreted,and the unique mechanical properties of the lithology of Shanzhai coal mine are established corresponding to the vibration measurement curve,and the corresponding relationship between the vibration measurement energy of the borehole and the lithology is established;the vibration measurement energy while drilling and the dynamic elastic modulus,the static elastic modulus,and the uniaxial resistance are respectively established in Shanzhai coal mine Linear model of compressive strength.5)based on the analysis of key layers and the results of early logging,the roof overburden structure of Shanzhai coal mine is analyzed and some measures for roof support and rock burst prevention are put forward.The paper has together 81 figures,12 tables and 87 references.