Control Mechanism Of Surrouding Rocks Related To Filling Roadway And Driving Along Goaf In High Gassy Mine

How to speed up the excavation efficiency and ease the tension of excavation and replacement are the problems that need to be solved in high gas mines.Reasonable utilization of gas pressure reduction areas in coal seams to reduce the frequency of anti-outburst measures can effectively improve tunneling efficiency.This article takes Xuandong No.2 coal mine III 3302 working face as the study object.Through experiments,theoretical calculations,numerical simulations,on-site monitoring and other means,we studied how to carry out roadway fill and go-ahead driving in deep mining and high gas mines.The high-water material was used as the main material,and the composition and ratio of the filler-filled slurry were given.Analyze the fracture of the overlying strata in the roadway,and give the coordination deformation relationship between the backfill and the direct roof,the basic roof.Proposed conditions for stability of backfills and critical blocks B.A mechanical structural model of the coal pillar-filled body was established to analyze the mechanical relationship between the coal pillar and backfill body.Analysis of factors influencing the plastic zone width of coal pillars using numerical calculation methods.Discloses the law of deformation and fracture of surrounding rock under different pillar widths and different filling body strengths.A comprehensive method for determining the width of coal pillars along the roadway in high gas mines is proposed to determine the reasonable range of coal pillar width.The above research was applied in engineering practice to verify the feasibility of in-situ filling roadway excavation in high gas mines.The main research contents of the article are as follows:?1?Develop filling slurry,give specific composition and ratio of filling slurry;test mechanical properties and flow properties of filling body;establish binary regression mathematical model of compressive strength of filling body;explanation of the filling process flow and parameters at the underground site.?1?The filling slurry that meets the requirements of on-site engineering was studied.The water-cement ratio of the filling slurry was determined to be 1.5:1 and the content of coal gangue was 10%.The mechanical properties of the filling body and the flow properties of the filling slurry were investigated experimentally.?2?Using Matlab software,a binary regression model was established.After regression analysis and testing,a mathematical prediction model of compressive strength was established and error analysis was performed on the prediction data.?3?Detailed description filling parameters and process flow during production process,and reinforcing structure of backfilling in underground tunnels.?2?Simplifies the mechanical relationship between the backfill and the upper rock,deduces the calculation formula of the cut resistance and the cut height of the backfill,analyzes the fracture structure of the top rock surrounding the backfill,and studies the relationship between the backfill and the roof.Coordinate the deformation relations;analyze the key blocks B and backfill bodies after the roof fractures to maintain stable judgment conditions.?1?By analyzing the monitoring data of the surrounding rock of the roadway filling roof,the fracture pattern of the overlying strata above the filling body is given,and the expressions of the cutting resistance and the cutting height of the backfill body are derived.?2?The relationship between the key block B,the subtraction amount?S_B,and the rotation angle?,and the determination conditions of self-stability are given.The coordination deformation relationship between the backfill and the direct top.?3?The stability of the filling body in the horizontal direction was studied.It was considered that the force acting on the gob side of the filling body could be approximated by using the Rankine's earth pressure formula,and the conditions for maintaining the balance of the filling body were proposed.?3?Taking the pillar-filled body as the research object,the mechanical model of the pillar-filling body was established to analyze the force characteristics of the coal pillar-filled body in the roadway filled with roadway,and the mechanical relationship between the pillar and the backfill was studied.The scope of the stress limit equilibrium area was calculated separately;the influence of gas pressure,support resistance,coal cohesion on the plastic zone of the surrounding rock was analyzed,and a numerical model was established to analyze the numerical analysis of different supporting schemes.?1?The characteristics of the narrow coal pillars along the empty roadway and the failure mechanism were studied.The ultimate strength(?_Jm,?_Jc)of the coal pillars and backfill can be calculated.?2?A mechanical model of the coal pillar-filled body was established to perform mechanical analysis on the contact surface between the coal pillar and the backfill body.The expression of the force F0 between the coal pillar and the backfill body was obtained to further analyze the relationship between the coal body and the backfill body.provide help.The two-mechanical model of coal pillar-filling body was established,and the calculation expressions of the plastic zones of the coal pillar and backfill were given respectively.?3?The mathematical calculation software Matlab was used to theoretically analyze the relationship between the radius of the plastic zone around the roadway along the excavation roadway,the strength of the filling body,the gas pressure in the coal seam,the support resistance,and the cohesive force in the coal.?4?The relationship between roadway and support of deep surrounding rock was studied,and the deformation curve of roadway was given.At the same time,the relationship between support resistance,radius of plastic zone of surrounding rock and displacement around the roadway was analyzed.?5?A method for determining the width of coal pillar-filled body in lane-filled roadways is proposed.It is considered that the width of coal pillar-filling body filled with gob-side entry roadway in high-incidence mine roadways must be combined with theoretical calculations,numerical simulations,engineering practices,and gas pressures.Measurements and other ranges are jointly determined.?4?The rock core samples were taken to measure the mechanical properties of the key stratum of the overburden rock.The stress distribution of the original rock above the coal seam was obtained through in-situ stress measurement,which provided more accurate data for numerical simulation analysis.The Flac3D numerical simulation software was used to analyze the stress and displacement of the surrounding rock of roadway along the roadway with different pillar widths and different filling body strengths.?1?Core samples were taken from key rock formations and rock mechanical parameters were measured.Through the measurement of ground stress level,it is concluded that the ground stress is dominated by horizontal tectonic stress.The vertical stress is the minimum principal stress,slightly smaller than the overburden gravity.?2?A numerical model was established to simulate the digging of coal pillar widths of 2m,3m,4m,5m,and 6m?filling body strength of 10MPa?and when the filling body strengths were 12MPa,10MPa,9MPa,and 8MPa?coal pillar width of4m?.The distribution of stress and displacement of roadways digging along roadways.?3?Through the analysis of the results of numerical simulation,the range of coal pillar width along the excavation road can be obtained under numerical simulation conditions.?4?According to the specific parameters of the existing support members,a model was created using Phase2 geotechnical software and numerical analysis was carried out for different support schemes to obtain the optimal support parameters for the roadway along the excavation road,and the support scheme for the roadway was determined.?5?According to the actual situation of on-site construction,combined with the theoretical analysis of the control of surrounding rock filled with roadway in the roadway,and using the monitoring data obtained from the site,the width of the pillar of the lane-dug roadway was proposed.The reasonable width of the coal pillars is comprehensively determined by the respective determined pillar ranges of theoretical calculations,numerical simulations,and engineering practices.Based on the analysis of mine pressure observation data during roadway excavation and mining,it is concluded that the way of filling lanes along the roadways in empty roads can effectively solve the difficulties of excavation and replacement of high-inrush mines.?1?According to the actual site conditions of the No.33302 face of Xuandong Mine,combined with the theoretical calculations,numerical simulations of the control of the surrounding rock of the roadway filled with excavation roadway in the previous section,and the use of on-site monitoring methods to obtain monitoring data,the comprehensive determination of roadway driving Coal pillar width.?2?The monitoring of pressure changes in backfills shows that,during monitoring of the upper working face,the force of the backfill is within its ultimate strength range.?3?During the process of roadway excavation and early mining,the deformation of roadway surrounding rock was analyzed through the observation of underground pressure.By means of surface displacement observation of the roadway,observation of roof separation,force monitoring of supporting elements and drilling of the roof,it is considered that the deformation of the surrounding rock during roadway excavation along the roadway is significantly less than during the mining period.The amount of deformation of the roof and floor of the roadway is less than the amount of deformation.?4?Through force monitoring and analysis of the support elements,it can be seen that the main force subjected to the narrow pillar driving along the empty roadway is the solid coal gang,which carries the weight of most overlying rock formations.Compared with the stress of the supporting members during the excavation,the supporting members are affected by the mining force during the mining process and have reached the limit,but are still within its tolerance range.?5?Through the drilling of the roof hole,the destruction of the deep surrounding rock with the working face during the excavation and mining was analyzed.There was no obvious damage to the surrounding rock during the excavation.The support design of the roadway played a significant role in the deformation of the surrounding rock.