Deep large-diameter multi-empty-hole straight-hole slotting method

Abstract

The invention discloses a deep large-diameter multi-empty-hole straight-hole slotting method. Firstly, a central blast hole is drilled in a rock surface needing to be excavated; a circle of empty holes are formed in the periphery of the center blast hole, the diameter of the empty holes is larger than that of the center blast hole, and the hole depth of the empty holes is larger than that of the center blast hole; a first blast hole and a second blast hole are formed in the periphery of the empty hole in a square shape, and the depth of the first blast hole and the depth of the second blast hole are the same as the depth of the central blast hole; the center blast hole, the first blast hole and the second blast hole are filled with explosives respectively, and hole openings are blocked through stemming; and the center blast hole, the first blast hole and the second blast hole are filled with explosives correspondingly, hole openings are blocked through stemming, and blasting slotting is achieved. Through the arrangement of the charging holes and the empty holes, a first small triangle, a second small triangle, a middle triangle and a large triangle which are most beneficial to rock crushing are formed, the areas of all the triangles are equal, distribution is compact and uniform, and it can be guaranteed that all the rocks can bear relatively balanced blasting energy during blasting.

Description

Technical Field

[0001] The present invention relates to the technical field of hard rock excavation. Specifically, it is a deep large-diameter multi-empty-hole parallel cut method. Background Art

[0002] When a collapse occurs during tunnel construction, it will cause construction delays and property losses. When there are trapped personnel, in order to carry out rescue safely and quickly, it may be the best choice to use the drill and blast method to excavate a small cross-section horizontal tunnel in hard rock and excavate to the position of the trapped personnel at the shortest distance. The key to the excavation of the horizontal tunnel is to increase the cycle footage. The key to increasing the cycle footage is the cut effect. Generally, the wedge cut form is used for the cut. Due to the small cross-sectional area of the horizontal tunnel, the wedge cut is limited by the cross-sectional width, and the drilling depth cannot be effectively increased. Only the parallel cut can be used. And when the rock hardness is relatively high, the conventional parallel cut method has low excavation efficiency and cannot meet the purpose of achieving the shortest distance excavation as soon as possible. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to provide a deep large-diameter multi-empty-hole parallel cut method that can improve the excavation speed under hard rock conditions and ensure the shortest distance excavation to form a small cross-section horizontal tunnel as soon as possible.

[0004] To solve the above technical problems, the present invention provides the following technical solution: A deep large-diameter multi-empty-hole parallel cut method, comprising the following steps:

[0005] Step A: Drill a central blast hole at the center of the rock face to be excavated;

[0006] Step B: Arrange a circle of empty holes around the central blast hole. The diameter of the empty holes is larger than the diameter of the central blast hole, and the depth of the empty holes is greater than the depth of the central blast hole;

[0007] Step C: Arrange the first blast holes and the second blast holes in a square around the outer periphery of the empty holes. The second blast holes are arranged at the vertices of the inclined square, and the first blast holes are arranged between two adjacent second blast holes. The depth of the first blast holes and the depth of the second blast holes are the same as the depth of the central blast hole; The second blast holes are arranged on the extension line of the connection line L2 between the center point of the central blast hole and the center point of any one of the empty holes; A first blast hole is arranged on the extension line of the connection line between the center point of the central blast hole and the midpoint of the connection line L1 formed by the center points of any two adjacent empty holes;

[0008] Step D: Load explosives into the central blast hole, the first blast holes and the second blast holes respectively, and seal the hole openings with stemming;

[0009] Step E: Detonate the explosives in the central blast hole, the first blast holes and the second blast holes to achieve blasting cut.

[0010] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, the first blast hole and the second blast hole are arranged at intervals, and the center points of the adjacent first blast holes and the center points of the second blast holes are sequentially connected to the center point of the center blast hole to enclose a first small triangle; the center points of two adjacent first blast holes and the center point of the second blast hole or the center point of the center blast hole are sequentially connected to enclose a second small triangle; the areas of the first small triangle and the second small triangle are equal.

[0011] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, both the first small triangle and the second small triangle are isosceles right triangles. The hypotenuses of the first small triangle and the second small triangle both pass through the center point of the empty hole, and one right side of the first small triangle passes between the two empty holes.

[0012] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, the center points of three adjacent first blast holes are sequentially connected to enclose a medium triangle, and the center points of two adjacent second blast holes and the center point of the center blast hole are also sequentially connected to enclose a medium triangle; the areas of any two of the medium triangles are equal.

[0013] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, the medium triangle is an isosceles right triangle, and the two right sides of the medium triangle respectively pass through the center points of two adjacent empty holes.

[0014] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, the center points of three adjacent second blast holes are sequentially connected to enclose a large triangle, and the areas of any two of the large triangles are equal.

[0015] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, the large triangle is an isosceles right triangle, and the hypotenuse of the large triangle passes through the center points of the two empty holes.

[0016] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, the depths of the first blast hole, the second blast hole and the center blast hole are equal, and the depth of the empty hole is 2 times the depth of the first blast hole; the charging length of the explosive is 80% of the depths of the center blast hole, the first blast hole and the second blast hole; the axes of the center blast hole, the empty hole, the first blast hole and the second blast hole are parallel to each other.

[0017] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, the diameters of the first blast hole, the second blast hole and the center blast hole are equal.

[0018] In the above-mentioned deep large-diameter multi-empty-hole straight-hole cut method, the diameters of the center blast hole, the first blast hole and the second blast hole are all 42 mm, and the diameter of the empty hole is 152 mm.

[0019] The technical solution of the present invention has achieved the following beneficial technical effects:

[0020] The microscopic structure of the rock is mainly triangular. Through the arrangement of blast holes and empty holes, the present invention forms the most favorable first small triangle, second small triangle, medium triangle and large triangle for rock fragmentation. The area of each triangle is equal, and the distribution is compact and uniform. Moreover, charging blast holes are arranged at equal intervals around each empty hole. During blasting, it can ensure that the rock everywhere can receive relatively balanced blasting energy. When blasting hard rock, it can maximize the degree of rock fragmentation and improve the excavation speed.

[0021] There is at least one empty hole in each triangle of the present invention. The empty hole has the following functions: (1) The empty hole has a stress concentration effect. The larger the diameter of the empty hole, the greater the maximum tensile stress generated between the charging hole and the empty hole, and the tensile strength of the rock is much lower than the shear strength and compressive strength of the rock. (2) The empty hole provides a free surface effect for the blasting of the charging hole. At the free surface, the rock bears tensile stress. Therefore, the free surface plays an important role in the fragmentation of the rock. (3) The empty hole has a pressure relief effect. The empty hole can change the in-situ stress state of the rock near the empty hole, release the in-situ stress in the rock around the empty hole, make it easy to break, and is conducive to improving the cut efficiency. The present invention uses a sufficient number of large-diameter empty holes to form a large-volume cavity, which provides a sufficiently large free surface for the blasting of subsequent blast holes, and solves the problem of difficult cut in the blasting excavation of small-section hard rock tunnels. The drilling depth of the empty hole is twice that of the charging hole, which can be used for 2 blasting cycles, reducing the number and time of drilling, reducing the number of cycles, and reducing the consumption of explosive materials; when conducting the first-cycle blasting, since the deep part of the empty hole also provides a free surface, the rock clamping force is reduced, and the empty hole provides a compensation space for rock fragmentation, achieving the effect of smooth excavation along the shortest distance, and ensuring that the explosion shock energy is fully absorbed by the rock, maximizing the utilization of explosive energy while ensuring blasting safety. Brief Description of the Drawings

[0022] Figure 1 The plan view of the arrangement of blast holes and empty holes of the present invention;

[0023] Figure 2 The top view of the arrangement of blast holes and empty holes of the present invention;

[0024] Figure 3 The schematic diagram of the first small triangle and the second small triangle of the present invention;

[0025] Figure 4 The schematic diagram of the medium triangle of the present invention;

[0026] Figure 5 The schematic diagram of the large triangle of the present invention.

[0027] The reference numerals in the figure are represented as follows: 1 - central blast hole; 2 - relief hole; 3 - first blast hole; 4 - second blast hole; 5 - explosive; 6 - first small triangle; 7 - medium triangle; 8 - large triangle; 9 - second small triangle. Specific implementation mode

[0028] The deep and large diameter multi-relief hole parallel cut method in this embodiment includes the following steps:

[0029] Step A: Drill 1 central blast hole 1 at the center of the rock face to be excavated. The diameter of the central blast hole 1 is 42 mm and the hole depth is 5 m.

[0030] Step B: Arrange a circle of relief holes 2 on the circumference with the central blast hole 1 as the center and a radius of 270 mm. The number of relief holes 2 is 4. The 4 relief holes 2 are respectively arranged at the upper, lower, left and right positions of the central blast hole 1. The diameter of the relief holes 2 is larger than that of the central blast hole 1. The diameter of the relief holes 2 is 152 mm. The hole depth of the relief holes 2 is greater than that of the central blast hole 1. The depth of the relief holes 2 is 2 times the depth of the first blast hole 3, and the depth of the relief holes 2 is 10 m.

[0031] Step C: The first blast holes 3 and the second blast holes 4 are arranged in a square on the periphery of the relief holes 2. The second blast holes 4 are arranged at the vertices of the obliquely placed square. The 4 second blast holes 4 are respectively arranged at the upper, lower, left and right positions of the central blast hole 1. The first blast holes 3 are arranged between two adjacent second blast holes 4. The depth of the first blast holes 3 and the depth of the second blast holes 4 are the same as the depth of the central blast hole 1. On the extension line of the connection line L2 between the center point of the central blast hole 1 and the center point of any one of the relief holes 2, there is a second blast hole 4. The distance between the central blast hole 1 and the second blast hole 4 is 540 mm. The connection line formed by the center points of any two adjacent relief holes 2 is the connection line L1. On the extension line of the connection line between the center point of the central blast hole 1 and the midpoint of the connection line L1, there is a first blast hole 3. The distance between the central blast hole 1 and the first blast hole 3 is 385 mm. The axes of the central blast hole 1, the relief holes 2, the first blast holes 3 and the second blast holes 4 are parallel to each other.

[0032] Step D: Install explosives 5 in the central blast hole 1, the first blast holes 3 and the second blast holes 4 respectively. The charging length of the explosives 5 is 80% of the depth of the central blast hole 1, the depth of the first blast holes 3 and the depth of the second blast holes 4. The charging depth is 4 m. The charging starts from the bottom of the hole, and 1 m at the hole mouth is blocked with stemming.

[0033] Step E: Use detonators to simultaneously detonate the explosives 5 in the central blast hole 1, the first blast holes 3 and the second blast holes 4 to achieve blasting cut.

[0034] When the first blast holes 3 and the second blast holes 4 are specifically arranged, such asFigure 3 As shown, in the clockwise direction, there are successively the 2# second blast hole 4, the 3# first blast hole 3, the 4# second blast hole 4... and the 9# first blast hole 3. The first blast holes 3 and the second blast holes 4 are arranged at intervals. The center points of the adjacent first blast holes 3 and the center points of the second blast holes 4 are successively connected to the center point of the central blast hole 1 to enclose a first small triangle 6. For example, the 2# second blast hole 4, the 3# first blast hole 3 and the 1# central blast hole 1 enclose the first small triangle 6. The center points of two adjacent first blast holes 3 and the center point of the second blast hole 4 or the center point of the central blast hole 1 are successively connected to enclose a second small triangle 9. For example, the 5# first blast hole 3, the 6# second blast hole 4 and the 7# first blast hole 3 enclose the second small triangle 9.

[0035] As Figure 3 As shown, the areas of the first small triangle 6 and the second small triangle 9 are equal. Both the first small triangle 6 and the second small triangle 9 are isosceles right triangles. The hypotenuses of the first small triangle 6 and the second small triangle 9 both pass through the center point of the empty hole 2. One right side of the first small triangle 6 passes through between the two empty holes 2.

[0036] As Figure 4 As shown, the center points of three adjacent first blast holes 3 are successively connected to enclose a middle triangle 7. The center points of two adjacent second blast holes 4 and the center point of the central blast hole 1 are successively connected to also enclose a middle triangle 7. The areas of any two of the middle triangles 7 are equal. The middle triangle 7 is an isosceles right triangle. The two right sides of the middle triangle 7 respectively pass through the center points of two adjacent empty holes 2.

[0037] As Figure 5 As shown, the center points of three adjacent second blast holes 4 are successively connected to enclose a large triangle 8. The areas of any two of the large triangles 8 are equal. The large triangle 8 is an isosceles right triangle. The hypotenuse of the large triangle 8 passes through the center points of the two empty holes 2.

[0038] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or alterations derived therefrom are still within the protection scope of the claims of this patent application.

Claims

1. A method for cutting deep, large-diameter, multi-hole straight-hole grooves, characterized in that: The following steps are involved: Step A: drilling a central blasthole (1) at the center of the rock surface to be excavated; Step B: a circle of empty holes (2) are arranged around the central blast hole (1), wherein the diameter of the empty holes (2) is greater than the diameter of the central blast hole (1), and the hole depth of the empty holes (2) is greater than the hole depth of the central blast hole (1); Step C: a first blast hole (3) and a second blast hole (4) are arranged in a square shape on the periphery of the empty hole (2), the second blast hole (4) is arranged at the vertex of the oblique square, the first blast hole (3) is arranged between two adjacent second blast holes (4), the depth of the first blast hole (3) and the depth of the second blast hole (4) are the same as the depth of the central blast hole (1); the second blast hole (4) is arranged on the extension line of the connecting line L2 between the center point of the central blast hole (1) and the center point of any one of the empty holes (2); the connecting line L1 is formed by connecting the center points of any two adjacent empty holes (2), and the first blast hole (3) is arranged on the extension line of the connecting line L1 between the center point of the central blast hole (1) and the midpoint of the connecting line L1; Step D: Explosives (5) are respectively placed in the central blast hole (1), the first blast hole (3) and the second blast hole (4), and the holes are sealed with blast hole mud; Step E: detonating the explosives (5) in the central blast hole (1), the first blast hole (3) and the second blast hole (4) to achieve blasting trenching.

2. A deep large diameter multi-hole straight-hole cutting method according to claim 1, characterized in that: The first blast holes (3) and the second blast holes (4) are arranged at intervals, and the center points of the adjacent first blast holes (3) and the second blast holes (4) are connected in sequence with the center point of the central blast hole (1) to form a first small triangle (6); the center points of the adjacent two first blast holes (3) and the center point of the second blast hole (4) or the center point of the central blast hole (1) are connected in sequence to form a second small triangle (9); the areas of the first small triangle (6) and the second small triangle (9) are equal.

3. A deep large diameter multi-hole straight-hole cutting method according to claim 2, characterized in that: The first small triangle (6) and the second small triangle (9) are both isosceles right triangles, the hypotenuse of the first small triangle (6) and the hypotenuse of the second small triangle (9) both pass through the center point of the empty hole (2), and a right-angled side of the first small triangle (6) passes between the two empty holes (2).

4. A deep large diameter multi-hole straight-hole cutting method according to claim 1, characterized in that: The center points of the three adjacent first blast holes (3) are connected in sequence to form a middle triangle (7), and the center points of the two adjacent second blast holes (4) and the center point of the central blast hole (1) are connected in sequence to form a middle triangle (7); the areas of any two middle triangles (7) are equal.

5. A deep large diameter multi-hole straight-hole cutting method according to claim 4, characterized in that: The middle triangle (7) is an isosceles right triangle, and the two right-angled sides of the middle triangle (7) respectively pass through the center points of two adjacent holes (2).

6. A deep large diameter multi-hole straight-hole cutting method according to claim 1, characterized in that: The center points of three adjacent second blast holes (4) are connected in sequence to form a large triangle (8), and the areas of any two of the large triangles (8) are equal.

7. A deep large diameter multi-hole straight-hole cutting method according to claim 6, characterized in that: The large triangle (8) is an isosceles right triangle, and the hypotenuse of the large triangle (8) passes through the center points of the two holes (2).

8. A deep large diameter multi-hole straight-hole cutting method according to claim 1, characterized in that: The depth of the hollow hole (2) is twice the depth of the first blast hole (3); the charging length of the explosive (5) is 80% of the depth of the central blast hole (1), the first blast hole (3) and the second blast hole (4); the axes of the central blast hole (1), the hollow hole (2), the first blast hole (3) and the second blast hole (4) are parallel to each other.

9. A deep large diameter multi-hole straight-hole cutting method according to claim 1, characterized in that: The diameters of the first blast hole (3), the second blast hole (4) and the central blast hole (1) are equal.

10. A deep large diameter multi-hole straight-hole cutting method according to claim 9, characterized in that: The diameters of the central blast hole (1), the first blast hole (3) and the second blast hole (4) are all 42 mm, and the diameter of the empty hole (2) is 152 mm.

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