Head-on pressure relief and scour prevention method for steeply-inclined super-thick coal seam tunneling roadway

Abstract

The invention provides a head-on pressure relief and scour prevention method for a steeply-inclined super-thick coal seam tunneling roadway, and belongs to the technical field of mines. The method comprises the steps that the head-on surrounding rock stress of the steeply-inclined super-thick coal seam tunneling roadway is collected, and the main impact influence stress is determined; determining a head-on surrounding rock stress peak value region and a potential peak value region of the steeply-inclined super-thick coal seam tunneling roadway; formulating a head-on surrounding rock pressure relief measure scheme of the steeply-inclined super-thick coal seam tunneling roadway; monitoring the value of energy released by surrounding rock failure; judging whether the rock burst danger exists or not based on the numerical value of the energy released by the damage of the surrounding rock, if so, changing the measure parameters of the head-on surrounding rock pressure relief measure scheme of the steeply-inclined super-thick coal seam tunneling roadway, and repeatedly judging whether the rock burst danger exists or not; according to the method, the rock burst of the surrounding rock is effectively reduced through scientific stress analysis and specific pressure relief measures, and the mine production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of mines, and in particular to a head-on pressure relief and anti-bumping method for tunneling a steeply inclined and extra-thick coal seam. Background Art

[0002] In the process of tunneling in coal mines, especially when facing steeply inclined and extra-thick coal seams, the high stress and rock burst in the surrounding rock are often a severe challenge, leading to serious consequences such as increased safety hazards in tunneling and reduced production efficiency. Because the stress on the lower surrounding rock under the conditions of steeply inclined and extra-thick coal seams is more complex, it is more prone to stress concentration and rock burst. The applicability of general coal seam tunneling roadway pressure relief and rock burst prevention methods in the face of steeply inclined and extra-thick coal seams is still unclear. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling, which reduces the impact of rock burst on tunneling in steeply inclined and extra-thick coal seams and ensures safe production and mining and excavation continuity in mines. Specifically, the method includes:

[0004] A method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling tunnels, comprising:

[0005] S1. Collect the surrounding rock stress of the steeply inclined and extra-thick coal seam tunneling tunnel and determine the main impact stress;

[0006] S2. Determine the peak area and potential peak area of ​​the surrounding rock stress of the steeply inclined and extra-thick coal seam tunneling tunnel according to the main impact influence stress and the surrounding rock stress;

[0007] S3, formulating a plan for unloading pressure on the surrounding rock of the steeply inclined and extra-thick coal seam tunnel according to the surrounding rock stress peak area and the potential peak area;

[0008] S4, monitoring the energy released by surrounding rock destruction according to the plan of pressure relief measures for the head-on surrounding rock of the steeply inclined and extra-thick coal seam tunneling tunnel;

[0009] S5. judging whether there is a rock burst danger based on the value of the energy released by the surrounding rock failure,

[0010] If yes, change the measure parameters of the surrounding rock pressure relief measure plan for steeply inclined and extra-thick coal seam tunneling tunnel, and repeat step S4;

[0011] If it does not exist, the current measures for unloading the surrounding rock pressure in the steeply inclined and extra-thick coal seam tunneling are effective.

[0012] Optionally, the step S3 of formulating a stress relief measure plan for the surrounding rock of the steeply inclined and extra-thick coal seam tunneling tunnel according to the surrounding rock stress peak area and the potential peak area includes:

[0013] Formulate blasting pressure relief measures for the main stress concentration area in front of the face, and carry out drilling and blasting towards the solid coal in the working face each time:

[0014] The blasting hole diameter is set to 42mm, the height from the tunnel floor is 1.0m-1.5m, the angle between the azimuth and the tunnel excavation direction is 0°, the number of the blasting holes is two, and the blasting holes are sealed with water cannon mud:

[0015] One of the blast holes is 11m long, the sealing length is more than 5m, and the charge weight is 1.8kg;

[0016] The other blast hole is 6m long, the sealing hole length is more than 5m, and the charge weight is 1.2kg;

[0017] The explosives used were Class III coal mine permitted emulsion explosives, and the detonators used coal mine permitted millisecond delay electric detonators, with forward charging and one-time detonation.

[0018] Formulate pressure relief measures for large-diameter drilling in the main stress concentration area in front of the head:

[0019] The diameter of the pressure relief hole is 130mm, 1.5m-1.8m away from the side of the tunnel, 1.8m-2.0m away from the bottom of the tunnel, and the angle between the azimuth and the tunnel excavation direction is 0°;

[0020] There are 2 pressure relief holes with a total length of 30m. The excess volume of the pressure relief holes after each excavation is no less than 25.2m.

[0021] Optionally, the S4 is implemented according to the plan of the head-on surrounding rock pressure relief measure for the steeply inclined and extra-thick coal seam tunneling tunnel, and the value of the energy released by the surrounding rock destruction is monitored, including:

[0022] The energy released by the surrounding rock destruction is monitored by microseismic, geosound and electromagnetic radiation.

[0023] Optionally, judging whether there is a rock burst danger based on the value of energy released by the surrounding rock failure in S5 includes:

[0024] If the value of the energy released by the surrounding rock destruction is greater than a preset value, it is determined that there is a risk of rock burst;

[0025] Otherwise, there is no danger of rock burst.

[0026] Optionally, the measure parameters in S5 include:

[0027] The measure parameters include:

[0028] The number of pressure relief holes, the length of pressure relief holes, the diameter of pressure relief holes, the number of blasting holes and the length of blasting holes.

[0029] Optionally, the measure parameters for changing the plan of pressure relief measures for the head-on surrounding rock of the steeply inclined and extra-thick coal seam excavation roadway in S5 include:

[0030] Supports changing one or more parameters in the action parameters each time;

[0031] The changes to the parameters of the measures described above follow the following rules:

[0032] One more pressure relief hole is added at a time;

[0033] Add one blasting hole at a time;

[0034] The increase in the length of the pressure relief hole for a single increase is 5m;

[0035] The increase in the length of a single blast hole is 1m;

[0036] The increase in the diameter of the single amplification pressure relief hole is 5mm.

[0037] Compared with the prior art, the above technical solution has at least the following beneficial effects:

[0038] This method first collects surrounding rock stress data to determine the main impact stress, stress concentration areas and potential concentration areas. Then, a targeted pressure relief measure plan is formulated, including technical means such as blasting and large-diameter drilling pressure relief, to reduce the stress level of the surrounding rock. Finally, the effect of the pressure relief measure plan is tested through the monitoring system to ensure its effective control of rock burst.

[0039] This method can effectively reduce the rock burst pressure of the surrounding rock, improve the mine production efficiency and ensure the continuity of mining and excavation through scientific stress analysis and specific pressure relief measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 It is a schematic diagram of the process of the present invention;

[0042] Figure 2 It is the numerical simulation model of 400B3 tunneling tunnel;

[0043] Figure 3This is the vertical stress distribution cloud diagram of 400B3 tunneling tunnel;

[0044] Figure 4 Horizontal stress distribution of 400B3 tunneling tunnel;

[0045] Figure 5 It is the horizontal stress distribution curve at the head of the tunnel;

[0046] Figure 6 is the horizontal stress distribution curve above the roadway;

[0047] Figure 7 It is a side cross-sectional view of a drilled and blasted hole;

[0048] Figure 8 It is a front view plan view of the pressure relief hole;

[0049] Fig. 9 It is a schematic diagram of the side cross-section of the pressure relief hole;

[0050] Fig.10 To demonstrate the effect of anti-impact application of head-on pressure relief measures in tunnel excavation. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "one" or "the" do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0053] It should be noted that the terms "up", "down", "left", "right", "front" and "back" used in the present invention are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0054] like Figures 1 to 6 As shown, a method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling includes:

[0055] S1. Collect the surrounding rock stress of the steeply inclined and extra-thick coal seam tunneling tunnel and determine the main impact stress; specifically include:

[0056] Collect vertical stress and horizontal stress at the head of the tunnel, which can be collected through computer simulation, numerical simulation calculation, on-site testing and other methods;

[0057] Determine the main impact influencing stress and compare the collected vertical stress and horizontal stress. If the vertical stress is significantly greater than the horizontal stress, the vertical stress is the main impact influencing stress; if the horizontal stress is significantly greater than the vertical stress, the horizontal stress is the main impact influencing stress.

[0058] S2. Determine the peak area and potential peak area of ​​the surrounding rock stress of the steeply inclined and extra-thick coal seam tunneling tunnel according to the main impact influence stress and the surrounding rock stress; specifically including:

[0059] Analyze the main stress concentration area of ​​the main impact in front of the tunnel head;

[0060] Analyze the main stress concentration area that affects the stress formation at the rear of the tunnel head and the distribution range of the stress concentration area relative to the tunnel space. The same distribution range relative to the area to be excavated is the potential stress concentration area.

[0061] S3, formulating a plan for unloading pressure on the surrounding rock of the steeply inclined and extra-thick coal seam tunnel according to the surrounding rock stress peak area and the potential peak area;

[0062] Specifically include:

[0063] Formulate blasting pressure relief measures for the main stress concentration area in front of the face, and carry out drilling and blasting towards the solid coal in the working face each time:

[0064] The blasting hole diameter is set to 42mm, the height from the tunnel floor is 1.0m-1.5m, the angle between the azimuth and the tunnel excavation direction is 0°, the number of the blasting holes is two, and the blasting holes are sealed with water cannon mud:

[0065] One of the blast holes is 11m long, the sealing length is more than 5m, and the charge weight is 1.8kg;

[0066] The other blast hole is 6m long, the sealing hole length is more than 5m, and the charge weight is 1.2kg;

[0067] The explosives used were Class III coal mine permitted emulsion explosives, and the detonators used coal mine permitted millisecond delay electric detonators, with forward charging and one-time detonation.

[0068] Formulate pressure relief measures for large-diameter drilling in the main stress concentration area in front of the head:

[0069] The diameter of the pressure relief hole is 130mm, 1.5m-1.8m away from the side of the tunnel, 1.8m-2.0m away from the bottom of the tunnel, and the angle between the azimuth and the tunnel excavation direction is 0°;

[0070] There are 2 pressure relief holes with a total length of 30m. The excess volume of the pressure relief holes after each excavation is no less than 25.2m.

[0071] like Figures 7 to 10 As shown, blasting pressure relief measures are formulated for the main stress concentration area in front of the face, and drilling and blasting are carried out towards the solid coal in the face of the working face each time;

[0072] The blasting hole diameter is 42mm, the height from the tunnel floor is 1.0-1.5m, the azimuth is the same as the tunnel excavation direction, and the angle is 0°;

[0073] The 1# blasting hole uses the drill cuttings hole after taking coal powder to load the explosives, and the 2# hole has a construction length of 6m;

[0074] The blasting holes are sealed with water cannon mud, of which the No. 1 hole is charged with 1.8 kg (6 small charges) and the length of the sealed hole is greater than 5 m; the No. 2 hole is charged with 1.2 kg (4 small charges) and the length of the sealed hole is greater than 3 m;

[0075] The explosive used is the third-level coal mine permitted emulsion explosive, and the detonator uses the coal mine permitted millisecond delay electric detonator, with forward loading and one-time detonation.

[0076] Formulate pressure relief measures for large-diameter drilling in the main stress concentration area in front of the head, and the specific parameters of the measures are:

[0077] The pressure relief hole has a diameter of 130 mm, is 1.5-1.8 m away from the tunnel side, 1.8-2.0 m away from the tunnel floor, and has an azimuth angle of 0° in the same direction as the tunnel excavation direction.

[0078] There are 2 pressure relief holes with a total length of 30m. The excess volume of the pressure relief holes after each excavation is no less than 25.2m.

[0079] S4, monitoring the energy released by surrounding rock destruction according to the plan of pressure relief measures for the head-on surrounding rock of the steeply inclined and extra-thick coal seam tunneling tunnel;

[0080] The energy released by the surrounding rock destruction is monitored by microseismic, geosound and electromagnetic radiation.

[0081] S5. judging whether there is a rock burst danger based on the value of the energy released by the surrounding rock failure,

[0082] If yes, change the measure parameters of the surrounding rock pressure relief measure plan for steeply inclined and extra-thick coal seam tunneling tunnel, and repeat step S4;

[0083] If it does not exist, the current measures for unloading the surrounding rock pressure in the steeply inclined and extra-thick coal seam tunneling are effective.

[0084] Optionally, judging whether there is a rock burst danger based on the value of energy released by the surrounding rock failure in S5 includes:

[0085] If the value of the energy released by the surrounding rock destruction is greater than a preset value, it is determined that there is a risk of rock burst;

[0086] Otherwise, there is no danger of rock burst.

[0087] Specifically, the measure parameters include:

[0088] The number of pressure relief holes, the length of pressure relief holes, the diameter of pressure relief holes, the number of blasting holes and the length of blasting holes.

[0089] Supports changing one or more parameters in the action parameters each time;

[0090] The changes to the parameters of the measures described above follow the following rules:

[0091] One more pressure relief hole is added at a time;

[0092] Add one blasting hole at a time;

[0093] The increase in the length of the pressure relief hole for a single increase is 5m;

[0094] The increase in the length of a single blast hole is 1m;

[0095] The increase in the diameter of the single amplification pressure relief hole is 5mm.

[0096] The method of this embodiment is further described below in conjunction with specific application scenarios:

[0097] This implementation case takes the +400mB3 excavation roadway of a Wudong coal mine as an example, and establishes a simulation numerical simulation model of the mine recovery working face through the FLAC3D numerical simulation software. According to the actual excavation steps, the excavation process of the +400B3 excavation roadway is simulated in the FLAC3D numerical simulation software, and the vertical stress and horizontal stress distribution of the +400B3 excavation roadway head during the excavation process are collected to determine the main impact influencing stress, stress concentration area and potential stress concentration area, formulate the roadway head pressure relief and anti-impact measures, and test the effectiveness of the measures. The specific steps are as follows:

[0098] According to the geological conditions of the mine, a numerical simulation model covering the +400B3 excavation roadway of Wudong Coal Mine was established to simulate the excavation process of the +400B3 roadway and collect the vertical stress and horizontal stress of the surrounding rock during the excavation of the +400B3 excavation roadway. Figure 2 is a numerical simulation model. Figure 3 is the vertical stress distribution of the surrounding rock after tunnel excavation. Figure 4 It is the horizontal stress distribution of surrounding rock after tunnel excavation.

[0099] Comparing the magnitude of vertical stress and horizontal stress, the peak value of horizontal stress near the tunnel head is about 33MPa, and the peak value of vertical stress near the tunnel head is about 14MPa. It can be seen that the horizontal stress of the surrounding rock is significantly greater than the vertical stress, which determines that the horizontal stress is the main impact stress.

[0100] By analyzing the horizontal stress concentration area of ​​the tunnel surrounding rock and the potential stress concentration area during excavation, it was determined that the horizontal stress concentration area was about 30m in front of the head, such as Figure 5 ; The analysis found that the area about 4m away from the upper and lower boundaries of the tunnel is a horizontal stress concentration area. It can be seen that the area about 4m away from the upper and lower boundaries of the area to be excavated is a potential horizontal stress concentration area, such as Figure 6 .

[0101] Formulate decompression measures for blasting large-diameter drilling in steeply inclined and extra-thick coal seams, such as Figure 7 As shown, the details are as follows:

[0102] The blasting hole diameter is 42mm, the height from the tunnel floor is 1.0-1.5m, the azimuth is the same as the tunnel excavation direction, and the angle is 0°;

[0103] The 1# blasting hole uses the drill cuttings hole after taking coal powder to load the explosives, and the 2# hole has a construction length of 6m;

[0104] The blasting holes are sealed with water cannon mud, of which the No. 1 hole is charged with 1.8 kg (6 small charges) and the length of the sealed hole is greater than 5 m; the No. 2 hole is charged with 1.2 kg (4 small charges) and the length of the sealed hole is greater than 3 m;

[0105] The explosive used is the third-level coal mine permitted emulsion explosive, and the detonator uses the coal mine permitted millisecond delay electric detonator, with forward loading and one-time detonation.

[0106] Develop pressure relief measures for large-diameter drilling in the main stress concentration area in front of the head, such as Figure 8 and Fig. 9 As shown, the specific measure parameters are:

[0107] The pressure relief hole has a diameter of 130 mm, and is 1.5-1.8 m away from the side of the tunnel and 1.8-2.0 m away from the tunnel floor. The azimuth is the same as the tunnel excavation direction, and the included angle is 0°. Figure 8 shown.

[0108] There are 2 pressure relief holes with a length of 30m. The excess volume of the pressure relief holes after each excavation is not less than 25.2m. Fig. 9 shown.

[0109] Through on-site implementation, it was found that after the implementation of this pressure relief and anti-bumping method, the energy of the ground sound at the head of the tunnel was significantly reduced. Fig.10 As shown, it shows that the risk of rock burst has been reduced and effectively controlled.

[0110] In summary, this embodiment provides a method for head-on pressure relief and anti-burst in steeply inclined and extra-thick coal seam tunneling. Through scientific stress analysis and specific pressure relief measures, the impact ground pressure of the surrounding rock can be effectively reduced, the mine production efficiency can be improved, and the mining and excavation continuity can be guaranteed.

[0111] This method first collects surrounding rock stress data to determine the main impact stress, stress concentration areas and potential concentration areas. Then, a targeted pressure relief measure plan is formulated, including technical means such as blasting and large-diameter drilling pressure relief, to reduce the stress level of the surrounding rock. Finally, the effect of the pressure relief measure plan is tested through the monitoring system to ensure its effective control of rock burst.

[0112] This method can effectively reduce the rock burst pressure of the surrounding rock, improve the mine production efficiency and ensure the continuity of mining and excavation through scientific stress analysis and specific pressure relief measures.

[0113] The following points need to be explained:

[0114] (1) The drawings of the embodiments of the present invention only involve structures related to the embodiments of the present invention. Other structures may refer to conventional designs.

[0115] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0116] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0117] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling, characterized in that: include: S1. Collect the surrounding rock stress of the steeply inclined and extra-thick coal seam tunneling tunnel and determine the main impact stress; S2. Determine the peak area and potential peak area of ​​the surrounding rock stress of the steeply inclined and extra-thick coal seam tunneling tunnel according to the main impact influence stress and the surrounding rock stress; S3, formulating a plan for unloading pressure on the surrounding rock of the steeply inclined and extra-thick coal seam tunnel according to the surrounding rock stress peak area and the potential peak area; S4, monitoring the energy released by surrounding rock destruction according to the plan of pressure relief measures for the head-on surrounding rock of the steeply inclined and extra-thick coal seam tunneling tunnel; S5. judging whether there is a rock burst danger based on the value of the energy released by the surrounding rock failure, If yes, change the measure parameters of the surrounding rock pressure relief measure plan for steeply inclined and extra-thick coal seam tunneling tunnel, and repeat step S4; If it does not exist, the current measures for unloading the surrounding rock pressure in the steeply inclined and extra-thick coal seam tunneling are effective.

2. The method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling according to claim 1 is characterized in that: The S3 step of formulating the stress relief measures for the surrounding rock of the steeply inclined and extra-thick coal seam tunneling tunnel according to the surrounding rock stress peak area and the potential peak area includes: Formulate blasting pressure relief measures for the main stress concentration area in front of the face, and carry out drilling and blasting towards the solid coal in the working face each time: The blasting hole diameter is set to 42mm, the height from the tunnel floor is 1.0m-1.5m, the angle between the azimuth and the tunnel excavation direction is 0°, the number of the blasting holes is two, and the blasting holes are sealed with water cannon mud: One of the blast holes is 11m long, the sealing length is more than 5m, and the charge weight is 1.8kg; The other blast hole is 6m long, the sealing hole length is more than 5m, and the charge weight is 1.2kg; The explosives used were Class III coal mine permitted emulsion explosives, and the detonators used coal mine permitted millisecond delay electric detonators, with forward charging and one-time detonation. Formulate pressure relief measures for large-diameter drilling in the main stress concentration area in front of the head: The diameter of the pressure relief hole is 130mm, 1.5m-1.8m away from the side of the tunnel, 1.8m-2.0m away from the bottom of the tunnel, and the angle between the azimuth and the tunnel excavation direction is 0°; There are 2 pressure relief holes with a total length of 30m. The excess volume of the pressure relief holes after each excavation is no less than 25.2m.

3. The method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling according to claim 2 is characterized in that: The S4 is implemented according to the plan of the head-on surrounding rock pressure relief measures for the steeply inclined and extra-thick coal seam tunneling tunnel, and the values ​​of the energy released by the surrounding rock destruction are monitored, including: The energy released by the surrounding rock destruction is monitored by microseismic, geosound and electromagnetic radiation.

4. The method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling according to claim 3 is characterized in that: The step S5 of judging whether there is a rock burst danger based on the value of the energy released by the surrounding rock failure includes: If the value of the energy released by the surrounding rock destruction is greater than a preset value, it is determined that there is a risk of rock burst; Otherwise, there is no danger of rock burst.

5. The method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling according to claim 4 is characterized in that: The measure parameters in S5 include: The measure parameters include: The number of pressure relief holes, the length of pressure relief holes, the diameter of pressure relief holes, the number of blasting holes and the length of blasting holes.

6. The method for head-on pressure relief and anti-bumping in steeply inclined and extra-thick coal seam tunneling according to claim 5 is characterized in that: The parameters of the measure for changing the pressure relief measure for the head-on surrounding rock of the steeply inclined and extra-thick coal seam excavation roadway in S5 include: Supports changing one or more parameters in the action parameters each time; The changes to the parameters of the measures described above follow the following rules: One more pressure relief hole is added at a time; Add one blasting hole at a time; The increase in the length of the pressure relief hole for a single increase is 5m; The increase in the length of a single blast hole is 1m; The increase in the diameter of the single amplification pressure relief hole is 5mm.

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