Distributed deep hole blasting scour prevention method in overlying rock roadway of coal seam main roadway group

Abstract

The invention relates to the technical field of coal, in particular to a distributed deep hole blasting scour prevention method in an overlying rock roadway of a coal seam main roadway group, which comprises the following steps of: determining a target layer according to the characteristics of an overlying rock layer of a roadway group which comprises at least three main roadways, a coal pillar is formed between every two adjacent main roadways; digging a pressure relief roadway in the target layer, wherein the pressure relief roadway extends in the length direction of the main roadways and is located between the at least two main roadways; drilling is conducted in the pressure relief roadway to form blast holes, and the blast holes extend in the inclination direction of the main roadway and penetrate through a target layer above the main roadway; and blasting is conducted in the blast holes so as to cover the preset ranges of the two sides of at least one main roadway in the inclination direction of the main roadway, and according to the distributed deep hole blasting scour prevention method in the overlying rock roadway of the coal seam main roadway group, the safety of the roadway can be improved.

Description

Technical Field

[0001] The invention relates to the field of coal technology, and in particular to a distributed deep hole blasting anti-bumping method in an overlying rock tunnel of a large coal seam tunnel group. Background Art

[0002] In coal seams with rock burst, the coal pillars between adjacent tunnels are the main bearing bodies of the tunnels, and the stress is highly concentrated. The coal pillars between adjacent tunnels will produce creep damage under long-term bearing, gradually weakening the bearing capacity of the coal pillars, resulting in a significant decrease in the stability of the tunnels, becoming the main factor inducing impact, increasing the risk of impact, and affecting the safety of the tunnels. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the embodiment of the present invention proposes a distributed deep hole blasting anti-bumping method in the overlying rock tunnel of a large coal seam tunnel group, which can improve the safety of the tunnel.

[0004] The method for distributed deep hole blasting and anti-bumping in the overlying rock tunnels of a large tunnel group in a coal seam according to an embodiment of the present invention comprises: determining the target layer according to the characteristics of the overlying rock layer of the tunnel group, the tunnel group comprising at least three large tunnels, and forming a coal pillar between two adjacent large tunnels; excavating a pressure relief tunnel in the target layer, the pressure relief tunnel extending along the length direction of the large tunnel and being located between at least two large tunnels; drilling in the pressure relief tunnel to form a blasting hole, the blasting hole extending along the dip direction of the large tunnel and passing through the target layer above the large tunnel; blasting in the blasting hole to cover a preset range on both sides of at least one of the large tunnels in its dip direction.

[0005] The distributed deep hole blasting anti-bumping method in the overlying rock tunnel of a large coal seam tunnel group according to the embodiment of the present invention can improve the safety of the tunnel.

[0006] In some embodiments, drilling in the pressure relief tunnel to form blasting holes includes: determining the number of blasting holes in each row according to the thickness of the target layer, each row of blasting holes includes at least one first blasting hole group and at least one second blasting hole group, the first blasting hole group and the second blasting hole group are relatively arranged in the inclination direction of the tunnel, at least one of the first blasting hole group and the second blasting hole group includes a first blast hole and a second blast hole arranged in sequence in the front-rear direction, and the drilling depth of the first blast hole is greater than the drilling depth of the second blast hole; determining the spacing distance between two adjacent rows of blast holes in the length direction of the tunnel according to the scope of blasting; drilling each row of blast holes using a drilling field, and drilling multiple rows of blast holes according to the spacing distance between two adjacent rows of blast holes.

[0007] In some embodiments, drilling is performed on each row of blasting holes using a drilling site, including: drilling in the pressure relief tunnel to form the first blast hole, the first blast hole extending along the inclination direction of the large tunnel and arranged upwardly inclined, the terminal hole position of the first blast hole being located outside the outermost large tunnel among multiple large tunnels; loading the first explosive into the first blast hole and sealing the first blast hole; drilling in the pressure relief tunnel to form the second blast hole, the second blast hole being arranged parallel to the first blast hole, the terminal hole position of the second blast hole being located at an end of the sealing section of the first blast hole adjacent to the first explosive; loading the second explosive into the second blast hole and sealing the second blast hole so that the explosion range of the second explosive is at least partially within the explosion range of the first explosive.

[0008] In some embodiments, the explosion range of the first explosive and the second explosive in the inclination direction of the main tunnel covers a plurality of preset ranges on both sides of the main tunnel in its inclination direction, and the preset range is 15-20m.

[0009] In some embodiments, when the first blast hole group and the second blast hole group in each row of blast holes are both a group, the terminal hole position of the first blast hole is located in the middle position of the target layer in the up and down directions, and the angle between the extension direction of the first blast hole and the horizontal plane of the main tunnel is A, and 5°≤A≤10°.

[0010] In some embodiments, when there are multiple groups of the first blasting hole groups and the second blasting hole groups in each row of blasting holes, the multiple groups of the first blasting hole groups are arranged at intervals in the vertical direction, and the multiple groups of the second blasting hole groups are arranged at intervals in the vertical direction, so that the explosion range of the first explosive and the second explosive in the vertical direction covers the size of the target layer in the vertical direction.

[0011] In some embodiments, multiple rows of blasting holes are drilled according to the spacing distance between two adjacent rows of blasting holes, including: determining the spacing distance between two adjacent rows of blasting holes according to the explosion range of the first explosive and the second explosive in the length direction of the tunnel to cover the size of the target layer in the length direction of the tunnel; drilling multiple rows of blasting holes in sequence and installing explosives; and blasting the explosives in the multiple rows of blasting holes in sequence using a backward method.

[0012] In some embodiments, the first blasthole and the second blasthole are spaced apart by a distance of 0.5-1 m in the length direction of the tunnel.

[0013] In some embodiments, the charging length of the explosive is 2 / 3 of the length of the blasthole, and the sealing length of the blasthole is 1 / 3 of the length of the blasthole.

[0014] In some embodiments, the pressure relief tunnel is located below a middle position of the target layer in a vertical direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of a method for preventing impact by distributed deep hole blasting in overlying rock tunnels of a large coal seam tunnel group according to an embodiment of the present invention.

[0016] Figure 2 Schematic diagram of a pressure relief tunnel according to an embodiment of the present invention.

[0017] Figure 3 yes Figure 2 Sectional view of II.

[0018] Reference numerals:

[0019] Lane group 1, main lane 11, first main lane 111, second main lane 112, third main lane 113, fourth main lane 114,

[0020] Coal pillar 12,

[0021] Overburden stratum 2, target stratum 21, mudstone 22, fine sandstone 23, pressure relief tunnel 3,

[0022] Blasting hole 4, first blasting hole group 41, second blasting hole group 42, first blast hole 43, final hole position 431 of the first blast hole, second blast hole 44. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0024] like Figure 1 As shown, the distributed deep hole blasting anti-bumping method in the overlying rock tunnel of the coal seam large tunnel group 11 of the embodiment of the present invention includes: determining the target layer 21 according to the characteristics of the overlying rock layer 2 of the tunnel group 1, the tunnel group 1 includes at least three large tunnels 11, and a coal pillar 12 is formed between two adjacent large tunnels 11; digging a pressure relief tunnel 3 in the target layer 21, the pressure relief tunnel 3 extends along the length direction of the large tunnel 11 and is located between at least two large tunnels 11; drilling in the pressure relief tunnel 3 to form a blasting hole 4, the blasting hole 4 extends along the dip direction of the large tunnel 11 and passes through the target layer 21 above the large tunnel 11; blasting is performed in the blasting hole 4 to cover a preset range on both sides of at least one large tunnel 11 in its dip direction.

[0025] It is understandable that the coal pillars 12 between the main tunnels 11 are the bearing structures of the main tunnels 11, and the stress is highly concentrated on the coal pillars 12. Under the impact of rock pressure, the coal pillars 12 are easily deformed, causing the main tunnel 11 to become unstable. The target layer 21 is a thick and hard rock layer in the overlying rock layer 2 of the tunnel group 1. The characteristics of the overlying rock layer 2 of the tunnel group 1 can be obtained through the drilling column chart, which can clearly show the lithology, thickness and structure of the rock layer, so as to determine the position and height of the thick and hard rock layer above the main tunnel 11, and then determine the target layer 21, and excavate the pressure relief tunnel 3 in the target layer 21 just above the middle of the tunnel group 1, and then drill holes in the pressure relief tunnel 3, so as to facilitate deep hole blasting of the target layer 21.

[0026] like Figure 2 and Figure 3 As shown, when the pressure relief tunnel 3 is excavated in the target layer 21, the position of the pressure relief tunnel 3 in the up-down direction can be determined according to the thickness of the target layer 21, and the position of the pressure relief tunnel 3 in the left-right direction can be determined according to the position of the large tunnel 11. For example, the pressure relief tunnel 3 is arranged in the middle position of the target layer 21 in the up-down direction, and the pressure relief tunnel 3 is arranged in the middle position of multiple large tunnels 11 in the left-right direction. By arranging the pressure relief tunnel 3 between the large tunnels 11 in the horizontal direction, it is convenient to drill holes to the left and right sides respectively in the pressure relief tunnel 3, and then it is convenient to blast the target layer 21 above the large tunnel 11 on the left and the large tunnel 11 on the right at the same time.

[0027] The blasting hole 4 extends in the left-right direction and passes through the target layer 21 above the main tunnel 11. The blasting hole 4 can be set on the left side of the pressure relief tunnel 3, or on the right side of the pressure relief tunnel 3, or on both the left and right sides of the pressure relief tunnel 3. When the blasting hole 4 is set on both the left and right sides of the pressure relief tunnel 3, the blasting hole 4 on the left side is formed by drilling from the left side of the pressure relief tunnel 3 to the left, and the blasting hole 4 on the right side is formed by drilling from the right side of the pressure relief tunnel 3 to the right, and the final hole position of the blasting hole 4 on the left side is located at the preset position on the left side of the leftmost main tunnel 11, and the final hole position of the blasting hole 4 on the right side is located at the preset position on the right side of the rightmost main tunnel 11.

[0028] For example, the tunnel group 1 may include two, three, four, or five large tunnels 11. When there are three large tunnels 11, the pressure relief tunnel 3 may be located between the first large tunnel 11 and the second large tunnel 11, or between the second large tunnel 11 and the third large tunnel 11, to ensure that when blasting is carried out in the blasting hole 4, the blasting range covers the preset range on both sides of the large tunnel 11 in the left and right directions.

[0029] For the convenience of description, this embodiment is described by taking four main tunnels 11 as an example. The four main tunnels 11 are the first main tunnel 111, the second main tunnel 112, the third main tunnel 113 and the fourth main tunnel 114 from left to right. The main tunnels 11 are generally parallel to each other, and a coal pillar 12 is formed between two adjacent main tunnels 11. The outer side of the outermost main tunnel 11 is solid coal. The pressure relief tunnel 3 is roughly located in the middle of the second main tunnel 112 and the third main tunnel 113 in the left-right direction.

[0030] Optionally, the interval distance between two adjacent main tunnels 11 in the left-right direction is 40m, and above the main tunnel 11 from bottom to top are mudstone 22 and fine sandstone 23, wherein the thickness of the mudstone 22 is 5.6m, and the thickness of the fine sandstone 23 is 9.7m. Since the mudstone 22 is relatively soft and the sandstone is relatively hard and thick, the sandstone is the target layer 21 in this embodiment, and the pressure relief tunnel 3 is arranged in the sandstone layer 11m above the main tunnel 11, and intensive deep hole blasting is carried out on the thick and hard fine sandstone 23. The deep hole blasting range covers 15m on the left and right sides of the main tunnel 11 in the left-right direction, so that the main tunnel 11 is in a low stress area to avoid stress concentration and increase the impact risk.

[0031] For example, the blasting range of the blasting hole 4 in the left and right directions covers a preset range of 15-20m on the left and right sides of the main tunnel 11, ensuring that the main tunnel 11 is in a low stress zone after blasting pressure relief.

[0032] In the embodiment of the present invention, a pressure relief tunnel 3 is excavated in advance in the target layer 21 above the tunnel group 1, and intensive deep hole blasting is performed on the target layer 21 above the main tunnel 11 in the pressure relief tunnel 3, so that the thick hard roof is weakened and transformed as a whole, and the original rock stress and structural stress level in the tunnel group 1 area are reduced in advance, thereby achieving safe use of the main tunnel 11 group in the low stress area, and greatly reducing the stress concentration degree and impact risk during the use of the tunnel group 1.

[0033] Furthermore, in this embodiment, the position of the target layer 21 is determined by the characteristics of the overlying rock stratum 2 of the tunnel group 1, and the pressure relief tunnel 3 is set in the middle position of the target layer 21. Deep hole blasting is achieved by drilling to the left and right sides from the pressure relief tunnel 3 at the same time, so that the blasting range covers a certain range of the target layer 21 above the main tunnel 11 in the left and right directions, thereby reducing the risk of rock burst during the use of the main tunnel 11 of the rock burst coal seam, and improving the safety of the main tunnel 11.

[0034] In some embodiments, drilling is performed in the pressure relief tunnel 3 to form blasting holes 4, including: determining the number of blasting holes 4 in each row according to the thickness of the target layer 21, each row of blasting holes 4 includes at least one group of first blasting holes 41 and at least one group of second blasting holes 42, the first blasting holes 41 and the second blasting holes 42 are arranged relatively in the inclination direction of the main tunnel 11, at least one of the first blasting holes 41 and the second blasting holes 42 includes a first blast hole 43 and a second blast hole 44 arranged in sequence in the front-rear direction, and the drilling depth of the first blast hole 43 is greater than the drilling depth of the second blast hole 44; determining the spacing distance between two adjacent rows of blasting holes 4 in the length direction of the main tunnel 11 according to the scope of blasting; drilling each row of blasting holes 4 using a drilling field, and drilling multiple rows of blasting holes 4 according to the spacing distance between two adjacent rows of blasting holes 4.

[0035] It should be noted that the greater the thickness of the target layer 21, the greater the number of blasting holes 4 arranged in each row of blasting holes 4 in the vertical direction, and the smaller the thickness of the target layer 21, the fewer the number of blasting holes 4 arranged in each row of blasting holes 4 in the vertical direction, and the minimum number is one. The number of blasting holes 4 in each row is determined by the thickness of the target layer 21 to ensure that the blasting range of the blasting holes 4 covers the size of the target layer 21 in the vertical direction, that is, to ensure that the target layer 21 can be penetrated in the vertical direction when blasting is performed in the blasting holes 4.

[0036] Specifically, Figure 2 and Figure 3 As shown, the inclination direction of the main tunnel 11 is consistent with the left-right direction, the length direction of the main tunnel 11 is consistent with the front-back direction, and each row of blasting holes 4 includes at least one first blasting hole group 41 located on the left and at least one second blasting hole group 42 located on the right.

[0037] The first blast hole group 41 includes a first blast hole 43 and a second blast hole 44 arranged in sequence in the front-to-back direction, and the second blast hole group 42 includes a first blast hole 43 and a second blast hole 44 arranged in sequence in the front-to-back direction. The first blast hole 43 in the first blast hole group 41 is drilled from the left side of the pressure relief tunnel 3 to the left, and the first blast hole 43 in the second blast hole group 42 is drilled from the right side of the pressure relief tunnel 3 to the right.

[0038] In this embodiment, the number of blasting holes 4 in each row is determined by the thickness of the target layer 21 to ensure that the blasting range of each row of blasting holes 4 can penetrate the target layer 21 in the up and down directions. The spacing distance between two adjacent rows of blasting holes 4 in the front-to-back direction is determined according to the blasting range of each row of blasting holes 4 in the front-to-back direction to ensure that the blasting range of the blasting hole 4 located in the front in the front-to-back direction is connected with the range of the blasting hole 4 located in the rear in the front-to-back direction, thereby ensuring that the blasting range of the explosives in the blasting hole 4 during blasting can penetrate the target layer 21 above the main tunnel 11 in the front-to-back direction.

[0039] In some embodiments, drilling is performed on each row of blasting holes 4 using a drilling site, including: drilling in the pressure relief tunnel 3 to form a first blast hole 43, the first blast hole 43 extends along the inclination direction of the main tunnel 11 and is arranged upwardly inclined, and the terminal hole position 431 of the first blast hole is located outside the outermost main tunnel 11 among the multiple main tunnels 11; loading the first explosive into the first blast hole 43 and sealing the first blast hole 43; drilling in the pressure relief tunnel 3 to form a second blast hole 44, the second blast hole 44 is arranged parallel to the first blast hole 43, and the terminal hole position of the second blast hole 44 is located at one end of the sealing section of the first blast hole 43 adjacent to the first explosive; loading the second explosive into the second blast hole 44 and sealing the second blast hole 44, so that the explosion range of the second explosive is at least partially within the explosion range of the first explosive.

[0040] Specifically, Figure 2 and Figure 3 As shown, the first blast hole 43 on the left extends from right to left and is arranged obliquely to the upper left, the final hole position 431 of the first blast hole is located 15m to the left of the leftmost tunnel 11, and the second blast hole 44 on the left is arranged in parallel with the first blast hole 43 on the left and is located in front of or behind the first blast hole 43 on the left. The first blast hole 43 on the right extends from left to right and is arranged obliquely to the upper right, the final hole position 431 of the first blast hole on the right is located 15m to the right of the rightmost tunnel 11, and the second blast hole 44 on the right is arranged in parallel with the first blast hole 43 on the right and is located in front of or behind the first blast hole 43 on the right.

[0041] Since a sealing length needs to be reserved at the position adjacent to the hole mouth in the blasting hole 4, that is, the charging length must be less than the blast hole length, resulting in the inability to blast at the sealing position, in this embodiment, a second blast hole 44 with a drilling length less than the first blast hole 43 is set, and the drilling depth of the second blast hole 44 is reasonably set, so that the charging position of the second blast hole 44 can cover the range of the sealing position of the first blast hole 43 that needs to be blasted, thereby ensuring that the target layer 21 above the left and right sides of the main tunnel 11 is blasted at the same time.

[0042] For example, a drilling site is set in the cross section of the pressure relief tunnel 3, and two holes are drilled on each side of the drilling site to form a first blast hole 43 and a second blast hole 44 on the left and right sides of the pressure relief tunnel 3, respectively. The depth of the first blast hole 43 is 84m, the depth of the second blast hole 44 is 21m, and the terminal hole position 431 of the first blast hole is set 15m outside the outermost large tunnel 11. The charge length in the first blast hole 43 is 56m, the sealing length is 28m, and the charge amount is 100kg. The charge length of the second blast hole 44 is 14m, the sealing length is 7m, and the charge amount is 50kg. The second blast hole 44 has a depth of 21m and is 7m away from the sealing section and charging section of the first blast hole 43. The second blast hole 44 can blast the sealing section of the first blast hole 43 at a position 7-14m away from the hole mouth, so that the blasting range of the explosive in the second blast hole 44 and the explosive in the first blast hole 43 can be connected in the left and right directions to avoid a blasting blind spot.

[0043] In this embodiment, a pressure relief tunnel 3 is excavated in the target layer 21 above the main tunnel 11, and a first blast hole 43 and a second blast hole 44 are drilled to the left and right sides of the pressure relief tunnel 3, and explosives are loaded into the first blast hole 43 and the second blast hole 44 for blasting, so that the blasting range of the explosives penetrates the target layer 21 in the up and down directions, and the blasting ranges of the first blast hole 43 and the second blast hole 44 in the left and right directions can be interconnected, so that the left and right preset ranges of the main tunnel 11 are covered in the left and right directions, so that the main tunnel 11 is within the horizontal projection area of ​​the blasting range, and the blasting range of the explosives penetrates the target layer 21 in the front and back directions, which is beneficial to the continuous fracturing of the thick hard roof effect and avoidance of mutual interference between the tunnel use and the pressure relief process, and the original rock stress and structural stress level of the main tunnel 11 are reduced in advance, so that the safe use of the tunnel in the low stress area can be achieved, thereby greatly reducing the stress concentration and impact risk during the use of the tunnel.

[0044] In some embodiments, the explosion range of the first explosive and the second explosive in the inclined direction of the tunnel 11 covers a plurality of preset ranges on both sides of the tunnel 11 in the inclined direction thereof, and the preset range is 15-20 m.

[0045] Specifically, the explosive range of the first explosive and the second explosive in the left and right directions must cover 15 m on the left and right sides of multiple large tunnels 11. That is to say, when there are four large tunnels 11, the blasting range of the first explosive and the second explosive must simultaneously cover 15 m on the left and right sides of the four large tunnels 11 to ensure that each large tunnel 11 is in a low stress zone.

[0046] Optionally, the preset range is 15m.

[0047] In some embodiments, when the first blast hole group 41 and the second blast hole group 42 in each row of blast holes 4 are both a group, the terminal hole position 431 of the first blast hole is located in the middle position of the target layer 21 in the vertical direction, so that the explosive in the first blast hole 43 can penetrate the target layer 21 in the vertical direction. The angle between the extension direction of the first blast hole 43 and the horizontal plane of the main tunnel 11 is A, and 5°≤A≤10°. By setting the first blast hole 43 to be arranged obliquely upward, since the first blast hole 43 and the second blast hole 44 are arranged in parallel, it is convenient to drill the first blast hole 43 and the second blast hole 44.

[0048] In some embodiments, when there are multiple groups of first blasting hole groups 41 and second blasting hole groups 42 in each row of blasting holes 4, multiple groups of first blasting hole groups 41 are arranged at intervals in the vertical direction, and multiple groups of second blasting hole groups 42 are arranged at intervals in the vertical direction, so that the explosion range of the first explosive and the second explosive in the vertical direction covers the size of the target layer 21 in the vertical direction. By providing multiple groups of blasting holes 4 arranged at intervals in the vertical direction, the explosives in the multiple groups of blasting holes 4 can penetrate the target layer 21 in the vertical direction during blasting, thereby ensuring the blasting effect.

[0049] That is, each row of blasting holes 4 includes multiple groups of first blasting hole groups 41 and multiple groups of second blasting hole groups 42, multiple groups of first blasting hole groups 41 include first blasting holes 43 and second blasting holes 44 arranged at intervals in the vertical direction, and multiple groups of second blasting hole groups 42 include first blasting holes 43 and second blasting holes 44 arranged at intervals in the vertical direction, avoiding blasting blind areas in the vertical direction. Multiple rows of blasting holes 4 are arranged at intervals in the front-to-back direction to avoid blasting blind areas in the front-to-back direction and ensure the blasting effect.

[0050] In some embodiments, multiple rows of blasting holes 4 are drilled according to the spacing distance between two adjacent rows of blasting holes 4, including: determining the spacing distance between two adjacent rows of blasting holes 4 according to the explosion range of the first explosive and the second explosive in the length direction of the tunnel 11 to cover the size of the target layer 21 in the length direction of the tunnel 11; drilling multiple rows of blasting holes 4 in sequence and installing explosives; blasting the explosives in the multiple rows of blasting holes 4 in sequence in a backward manner to achieve overall weakening of the thick and hard roof, and ensure that the pre-cracking range of the roof covers the tunnel 11, and after completing the deep hole blasting at the previous position, conducting the deep hole blasting at the next position until the pre-cracking work of the roof overlying all the tunnels 11 is completed.

[0051] Specifically, the spacing between the two rows of blasting holes 4 is determined according to the explosion range of the first explosive and the second explosive in the front and rear directions, ensuring that the explosion range of the first explosive and the second explosive at the front side can be connected with the explosion range of the first explosive and the second explosive at the rear side, avoiding the occurrence of a blasting blind area.

[0052] For example, the spacing between two adjacent rows of blasting holes 4 is 10 m.

[0053] In some embodiments, the spacing distance between the first blast hole 43 and the second blast hole 44 in the length direction of the tunnel 11 is 0.5-1m. By limiting the spacing distance between the first blast hole 43 and the second blast hole 44 in the front-to-back direction, it is avoided that the first blast hole 43 and the second blast hole 44 are set too close, which increases the construction difficulty, and it is also avoided that the first blast hole 43 and the second blast hole 44 are set too far, which affects the blasting effect of the second blast hole 44 on the sealing section of the first blast hole 43.

[0054] Optionally, the spacing distance between the first blast hole 43 and the second blast hole 44 in the front-to-back direction is 0.5 m.

[0055] In some embodiments, the charge length of the explosive is 2 / 3 of the length of the blasthole, and the sealing length of the blasthole is 1 / 3 of the length of the blasthole. Since the explosion of the explosive in the blasthole will generate an explosion shock wave and explosive gas, by limiting the charge length and the sealing length, it can be ensured that the explosive fully explodes in the blasthole while increasing the resistance of the hole, so that the explosive power acts more effectively on the rock and improves the blasting effect.

[0056] In some embodiments, Figure 3 As shown, the pressure relief tunnel 3 is located below the middle position of the target layer 21 in the vertical direction. Since the drilling site generally drills upwards in an inclined manner, by limiting the position of the pressure relief tunnel 3, it is convenient to make the final hole position of the blasting hole 4 located in the middle position of the target layer 21 in the vertical direction while drilling in the pressure relief tunnel 3, which is beneficial for the blasting range of the explosives in the blasting hole 4 to penetrate the target layer 21 in the vertical direction.

[0057] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0061] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0062] It is to be understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A distributed deep hole blasting anti-bumping method in the overlying rock tunnel of a coal seam large tunnel group, characterized in that: include: Determine the target layer according to the characteristics of the overlying rock layer of the tunnel group, wherein the tunnel group includes at least three large tunnels, and a coal pillar is formed between two adjacent large tunnels; Excavating a pressure relief tunnel in the target layer, wherein the pressure relief tunnel extends along the length direction of the main tunnel and is located between at least two main tunnels; Drilling in the depressurization tunnel to form a blasting hole, wherein the blasting hole extends along the dip direction of the main tunnel and passes through the target layer above the main tunnel; Blasting is carried out in the blasting holes to cover a preset range on both sides of at least one of the main tunnels in its inclination direction.

2. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 1 is characterized in that: Drilling holes in the pressure relief tunnel to form blasting holes includes: Determine the number of blast holes in each row according to the thickness of the target layer, each row of blast holes includes at least one first blast hole group and at least one second blast hole group, the first blast hole group and the second blast hole group are arranged relatively in the inclination direction of the tunnel, at least one of the first blast hole group and the second blast hole group includes a first blast hole and a second blast hole arranged in sequence in the front-rear direction, and the drilling depth of the first blast hole is greater than the drilling depth of the second blast hole; Determine the spacing between two adjacent rows of blasting holes in the length direction of the main tunnel according to the blasting range; Each row of blasting holes is drilled using a drilling site, and multiple rows of blasting holes are drilled according to the interval distance between two adjacent rows of blasting holes.

3. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 2 is characterized in that: Drilling of each row of blast holes using a drill yard includes: Drilling in the pressure relief tunnel to form the first blast hole, the first blast hole extending along the inclination direction of the main tunnel and arranged obliquely upward, the terminal hole position of the first blast hole being located outside the outermost main tunnel among the multiple main tunnels; Filling the first explosive into the first blasthole and sealing the first blasthole; Drilling in the depressurization tunnel to form the second blasthole, the second blasthole being arranged in parallel with the first blasthole, and the terminal position of the second blasthole being located at one end of the sealing section of the first blasthole adjacent to the first explosive; The second blasthole is filled with a second explosive and the second blasthole is sealed so that the explosion range of the second explosive is at least partially located within the explosion range of the first explosive.

4. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 3 is characterized in that: The explosion range of the first explosive and the second explosive in the inclination direction of the main tunnel covers a plurality of preset ranges on both sides of the main tunnel in its inclination direction, and the preset range is 15-20m.

5. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 4 is characterized in that: When the first blast hole group and the second blast hole group are both a group in each row of blast holes, the terminal hole position of the first blast hole is located in the middle position of the target layer in the up and down direction, and the angle between the extension direction of the first blast hole and the horizontal plane is A, and 5°≤A≤10°.

6. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 4 is characterized in that: When there are multiple groups of the first blasting hole groups and the second blasting hole groups in each row of blasting holes, the multiple groups of the first blasting hole groups are arranged at intervals in the vertical direction, and the multiple groups of the second blasting hole groups are arranged at intervals in the vertical direction, so that the explosion range of the first explosive and the second explosive in the vertical direction covers the size of the target layer in the vertical direction.

7. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 4 is characterized in that: Drilling multiple rows of blasting holes according to the interval between two adjacent rows of blasting holes includes: Determine the spacing between two adjacent rows of blasting holes according to the explosion range of the first explosive and the second explosive in the length direction of the main tunnel, so as to cover the size of the target layer in the length direction of the main tunnel; Drilling multiple rows of blast holes sequentially and installing explosives; The explosives in multiple rows of blasting holes are blasted in sequence using a backward method.

8. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 4 is characterized in that: The first blasthole and the second blasthole are spaced apart from each other by 0.5-1 m in the length direction of the main tunnel.

9. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 4 is characterized in that: The charging length of the explosive is 2 / 3 of the length of the blasthole, and the sealing length of the blasthole is 1 / 3 of the length of the blasthole.

10. The method for preventing impact by distributed deep hole blasting in overlying rock tunnels of coal seam large tunnel groups according to claim 1 is characterized in that: The pressure relief tunnel is located below the middle position of the target layer in the up-down direction.

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