Special design and safety technical measures for coal seam prevention (including vertical shaft and inclined shaft)
(1) Project Overview 1. Lane engineering Briefly describe the application of the tunnel, the construction orientation and slope, the support mode, the roadway section, the head position and the control of the measuring point, the expected uncovering position and the length of the exposed coal. Peripheral mining conditions (including coal pillars, goaf, ground drilling) and mining activities. 2. Coal seam occurrence and fault structure Expose coal layers, coal thickness, spacing, seam occurrence (strike, dip, dip), a bottom seam roof slate, structure, adjacent to the seam exposing conditions, the region geology, coal exposing the roadway configuration and control range Degree and so on. 3. Coal seam gas conditions The gas content, the amount of gushing, and the parameters of the outburst (the measured maximum gas pressure) in the structural unit area and adjacent areas are prominent points and basic conditions in history. It is estimated that the coal seam gas content and gas pressure at the coal uncovering site. Preliminary evaluation of the outstanding risk level of the coal mining area. 4. Local ventilation system The situation of the ventilation system, the relevant area affected by the return of coal. The ventilation system must be independent and reliable. 5. Uncover coal construction organization Briefly describe the organization and arrangement of coal mining and anti-sag construction, and attach the roadway to prevent and explode coal. (2) Front exploration drilling design 1. Drilling design The number of front exploration holes, the control range and the hole number of the core drilling hole are determined, and the normal distance from the coal seam to be uncovered is implemented. Attachment: Drill design flat, section, section and parameter list. 2. Drilling construction requirements (1) The scope of the front-drilling control, the core of the measuring core, etc. must comply with the anti-burst regulations and the company's relevant requirements. (2) After drilling, the drilling hole must be submitted, the coal depth, the coal length, the final hole length, the core drilling core (coal) core take-up rate, and the construction process with or without orifices. Anomalies such as top drills. Attached to the borehole to control the geological level (cut) and section view of the coal seam. (3) Pressure measurement and sampling hole design 1. Drilling design and construction Opening position (minimum distance from the coal seam to be uncovered), drilling parameters and contents of coal sample measurement, number of pressure measuring holes (not less than 3, with conditions can also serve as pressure measuring holes). 2. Pressure measuring method, sealing process and requirements (1) The pressure-measuring borehole must penetrate the whole coal. If it cannot penetrate at one time, it must enter the coal seam not less than 10m, and the rock section should be sealed at the whole process. (2) ΔP, f value and a, b adsorption constant, industrial index, gas content W, etc. should be measured during sampling. (3) If water is discharged, it is necessary to increase the design of grouting and water shutoff. (4) Defining the gas pressure observation time interval and observation time. (4) Regional outburst risk prediction 1. Outstanding hazard zoning of coal uncovering locations The post-expansion forecast results of the uncovering coal location, that is, whether the uncovering coal location is in a prominent danger zone or no outstanding danger zone. 2. Prediction of coal seam outburst danger The direct measured value of the measured gas pressure P or gas content W is predicted. Gas pressure or gas content exceeds the critical index as a prominent danger zone; in the construction process of various types of drilling, such as prediction and prediction, where the dynamic phenomenon occurs, it is directly determined as a prominent danger zone. 3. Gas pressure or gas content determination The direct measurement of coal seam gas pressure P or gas content W before the minimum normal distance of 10 m from the coal seam shall be advanced to 20 m. For the new level of coal uncovered or non-prominent coal seams in the non-prominent danger zone and the first uncovering of coal in the new mining area, it shall also be implemented in accordance with this requirement. (5) Outstanding measures for regional prevention and treatment 1. Design of pre-extracted coal seam gas measures (1) The minimum normal distance from the coal seam is not less than 7m (when the rock is broken or the geological structure is properly increased), the pre-extraction of the drilling hole area is carried out. (2) The drilling control range must meet the requirements of the anti-burst regulations. The drilling design parameters should be accompanied by the drilling arrangement (flat, section, section) and parameter table. (3) Defining the design basis of the drilling distance (the distance from the drilling axis of the coal section). (4) Defining the control scope and construction quality guarantee measures for the extraction drilling. (5) Design of extraction system, division of extraction unit, pre-extraction time, etc. (6) When using anti-evaluation measures such as hydraulic punching, it is necessary to attach relevant design; clearly identify the drainage protection measures during the coal uncovering period. (7) If the coal seam group spacing is less than 5m, it is necessary to eliminate the protruding danger at the same time. 2. Drilling construction and management Defining the drilling method calibration method, construction sequence, mapping, analysis, and hole filling measures. 3. Gas drainage metering management Clear gas extraction, gas drainage measurement methods, clear coal washing methods and statistical methods for flushing coal. 4. Step-by-step regional elimination design Requirement: For the small angle between the roadway and the coal seam can not completely eliminate the prominent danger of the coal seam in the coal mining area, it is necessary to formulate a step-by-step implementation area to eliminate the dangerous design. 5. Mining protection layer Explain whether the protective layer and protective effect have been mined at the uncovering location, whether there is a coal pillar and the scope of influence. (6) Inspection of the effectiveness of regional measures 1. Effect test drilling design Explain the regional measures effect test method, the number of test holes, the design parameters of the test holes, the critical value of the test parameters, and the design parameter table for peace, section and section layout. 2. Gas pre-extraction rate A method for measuring the pre-extraction rate of coal seam gas in the pre-extraction area is greater than 50%. 3. The amount of coal washed out The drilling control range rushes out the coal volume to 20 times the thickness of the coal seam as the elimination of the outstanding danger. The statistical calculation method should be explained. (7) Regional verification (work surface prediction) 1. Area verification (work surface prediction) location Before the minimum distance of the coal seam to be uncovered is 5m. 2. Regional verification method 3. Verify the number of holes and verify the hole design parameters 4. Verify parameters and their critical values Attached to the drilling design parameter table, peace, section, section layout. (8) Work face prevention measures 1. Basis for taking preventive measures on the work surface 2. Working face prevention measures Explain the specific content of the anti-burst measures on the working surface (with the drilling design parameter table, peace, section, section layout). (9) Inspection of the effect of the anti-burst measures on the working face 1. Inspection methods and indicators 2. Validation requirements Defining the design and technical requirements for each inspection (number of drill holes, drilling depth, control range, and drilling design parameters table, peace, section, section layout). 3. Verify effective lead distance (10) Security protection Ventilation facility Clearly identify the quantity, location and specification quality of the front and back dampers in the coal uncovering system. 2. Power supply system Briefly describe the power supply system, cable, switch and equipment layout before and after coal uncovering in the coal uncovering area. Overload, ground leakage protection calculation. 3. Monitoring and monitoring Clear the number and position of the high and low concentration gas sensor installation, the set alarm point, the power-off point, the re-power point and the power-off range. 4. Long-distance blasting The requirements for long-distance blasting are clarified in accordance with the regulations, and the starting and ending positions of the long-distance blasting, the location of the blasting, the blackout, the withdrawal, the warning range (and the drawing), and the blasting chart are clarified. 5. Safety facilities Blasting spray, purification spray, explosion-proof facilities, self-rescue and self-rescue, and location and requirements for refuge chambers. 6. Disaster avoidance route The text explains the route of avoidance. (11) Safety technical measures 1. Ensure measures are in place for construction 2. Ensure personnel safety measures during construction (12) Drawings 1. Comprehensive column diagram of coal and rock formation (1:200) 2. Roadway geological section (1:1000), horizontal section (1:1000) 3. Coal seam floor contour map (1:1000) 4. Comprehensive plan of mining engineering (1:1000) 5. Geological exploration hole and pressure measuring hole (predicting hole) layout flat, section, section view (1:200), pressure sealing and sealing process diagram (1:200) 6. Measures drilling design and control range (1:200) 7. Ventilation system map and disaster avoidance route map (1:2000) 8. Power supply, power off system schematic High Precision ER COLLET DIN6499, also known as spring collet, is mounted on a drill \ milling machine, drilling and milling chuck, its function is to clamp drill cutter or knife. Er flexible collet is currently the most used. 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