Carbon dioxide fracturing device cutting structure and blasting method for hard rock tunnel

Abstract

The present invention discloses a carbon dioxide fracturing device slotting structure and a blasting method for a hard rock tunnel. The carbon dioxide fracturing device slotting structure for a hard rock tunnel comprises a central fracturing hole, an empty hole, a first circle of blast holes and a second circle of blast holes. The carbon dioxide fracturing device slotting blasting method for a hard rock tunnel comprises the following steps: installing a carbon dioxide fracturing device, first simultaneously detonating the carbon dioxide fracturing device in the central fracturing hole and the fracturing device in the first slotting fracturing hole, and then detonating the carbon dioxide fracturing device in the second slotting fracturing hole. In the present invention, the carbon dioxide fracturing device in the central fracturing hole and the carbon dioxide fracturing device in the first slotting fracturing hole are detonated simultaneously. Under the action of the multi-directional blasting inside and outside, the rock is fully squeezed and crushed, and the rock crushing effect is better than that of the central hole being a simple empty hole. The triangular arrangement of the fracturing holes makes the rock more susceptible to shear damage. When the blasting stress wave reaches the free surface, it will be reflected into a tensile wave. The rock is crushed and thrown out under the joint action of the shear force and the tensile force.

Description

Technical Field

[0001] The invention relates to the technical field of carbon dioxide fracturing slot cutting, and more specifically to a carbon dioxide fracturing slot cutting structure and a blasting method for a hard rock tunnel. Background Art

[0002] In recent years, non-explosive rock breaking technology has received widespread attention at home and abroad, and a variety of new rock breaking technologies have been formed. Carbon dioxide blasting technology is a high-pressure gas blasting technology. When using carbon dioxide fracturing devices for tunnel excavation operations, how to reasonably arrange blastholes to maximize the energy utilization of carbon dioxide fracturing devices and improve the blasting effect is an urgent problem to be solved. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to provide a carbon dioxide fracturing groove cutting structure and a blasting method for a hard rock tunnel with reasonable blasthole arrangement and improved blasting effect.

[0004] To solve the above technical problems, the present invention provides the following technical solutions: a carbon dioxide fracturing device slotting structure for a hard rock tunnel, comprising a central fracturing hole, an empty hole, a first circle of blast holes and a second circle of blast holes; the central fracturing hole is arranged along the axis of the tunnel, the empty hole is arranged around the central fracturing hole, the first circle of blast holes is arranged in the outer circle of the empty hole, and the second circle of blast holes is arranged in the outer circle of the first circle of blast holes; the first circle of blast holes is composed of first slotting fracturing holes, and the second circle of blast holes is composed of second slotting fracturing holes.

[0005] In the above-mentioned carbon dioxide fracturing device slotting structure for hard rock tunnel, the empty hole is opened at the midpoint of the center connection line of any two adjacent first slotting fracturing holes.

[0006] The above-mentioned carbon dioxide fracturing device slotting structure for hard rock tunnel has one of the above-mentioned empty holes arranged on the radius extension line from any one of the above-mentioned empty holes to the central fracturing hole.

[0007] In the above-mentioned carbon dioxide fracturing device slotting structure for hard rock tunnels, the empty holes are arranged at equal intervals on a circle with the central fracturing hole as the center.

[0008] The above-mentioned carbon dioxide fracturing device slotting structure for hard rock tunnels has a second slotting fracturing hole arranged on an extension line of a radius from the central fracturing hole to any one of the empty holes; and a second slotting fracturing hole is also arranged on an extension line of a radius from the central fracturing hole to any one of the first slotting fracturing holes.

[0009] In the above-mentioned carbon dioxide fracturing device slotting structure for hard rock tunnel, one of the second slotting fracturing holes is arranged on the extension line of the radius from any one of the second slotting fracturing holes to the central fracturing hole.

[0010] The above-mentioned carbon dioxide fracturing device slotting structure for hard rock tunnels is characterized in that the second slotting fracturing holes are arranged at equal intervals on a circle with the central fracturing hole as the center.

[0011] In the above-mentioned carbon dioxide fracturing slotting structure for hard rock tunnel, the empty hole is opened at the midpoint of the center connection line of any two adjacent first slotting holes; one second slotting hole is arranged on the extension line of the radius from the center hole to any one of the empty holes; one second slotting hole is also arranged on the extension line of the radius from the center hole to any one of the first slotting holes; one empty hole is arranged on the extension line of the radius from any one of the empty holes to the center hole; one second slotting hole is arranged from any one of the second slotting holes to the extension line of the radius of the center hole; the empty holes are arranged at equal intervals on the circumference with the center hole as the center; the second slotting holes are arranged at equal intervals on the circumference with the center hole as the center.

[0012] In the above-mentioned carbon dioxide fracturing device slotting structure for hard rock tunnels, the center point of the central fracturing hole and the connecting line of the center points of any two adjacent first slot fracturing holes form an isosceles triangle, and an empty hole is set in the middle of any one of the isosceles triangles; in any isosceles triangle: the center distance between the empty hole and the central fracturing hole is equal to the center distance between any one of the two adjacent first slot fracturing holes and the empty hole; the diameters of the central fracturing hole, the empty hole, the first slot fracturing hole and the second slot fracturing hole are the same and are all perpendicular to the working surface, and the central fracturing hole, the empty hole, the first slot fracturing hole and the second slot fracturing hole are all perpendicular to the working surface, and the central fracturing hole, the empty hole, the first slot fracturing hole and the second slot fracturing hole are all perpendicular to the working surface, and the central fracturing hole, the empty hole, the first slot fracturing hole and the second slot fracturing hole are all perpendicular to the working surface, and the central fracturing hole, the empty hole, the first slot fracturing hole and the second slot fracturing hole are all perpendicular to the working surface, and the central fracturing hole, the empty hole, the first slot fracturing hole and the first ... The diameter range of the first hole and the second groove-induced crack hole is 60-150mm; the number of the empty holes is four, and the four empty holes are arranged in a square, the centers of the four empty holes are respectively located at the vertices of the four corners of the square, and the center point of the square coincides with the center of the central crack hole; the center distance between two adjacent empty holes is 600mm; the first circle of blast holes includes four first groove-induced crack holes, and the second circle of blast holes includes eight second groove-induced crack holes, the center distance between the first groove-induced crack hole and the central crack hole is 600mm, and the center distance between the second groove-induced crack hole and the central crack hole is 1000mm.

[0013] A carbon dioxide fracturing device slotting blasting method for a hard rock tunnel comprises the following steps:

[0014] Step A: inserting carbon dioxide fracturing devices into the central fracturing hole, the first cut-out fracturing hole of the first circle of blastholes, and the second cut-out fracturing holes of the second circle of blastholes, respectively, and the empty holes are vacant holes;

[0015] Step B: The carbon dioxide fracturing device in the central fracturing hole and the carbon dioxide fracturing device in the first slot fracturing hole are detonated simultaneously, and then the carbon dioxide fracturing device in the second slot fracturing hole is detonated.

[0016] The technical solution of the present invention achieves the following beneficial technical effects:

[0017] 1. In the present invention, the carbon dioxide fracturing device in the central fracturing hole and the carbon dioxide fracturing device in the first cutout fracturing hole are detonated simultaneously. Under the action of the internal and external multi-directional blasting, the rock is fully squeezed and crushed, and the rock crushing effect is better than that of the central hole being a simple empty hole.

[0018] 2. In the present invention, there are two empty holes between the central fracturing hole and each first groove fracturing hole, and the empty holes are free surfaces to ensure that the rock can be broken; when the blasting stress wave reaches the free surface, it will be reflected into a tensile wave. When the tensile wave is greater than the tensile strength of the rock, a Hawkinson effect will be generated to improve the blasting effect. At the same time, the reflected tensile wave and the stress field at the tip of the radial crack are superimposed on each other, which promotes the further expansion of the radial crack and the annular crack, greatly increasing the range of the crack area.

[0019] 3. In the present invention, the central fracturing hole and the two adjacent first slot fracturing holes in the adjacent first circle of blast holes all form an isosceles triangle. The rock between the central fracturing hole and the two first slot fracturing holes will produce stress superposition under the action of high-pressure carbon dioxide gas. The triangular arrangement of the fracturing holes makes the rock more susceptible to shear failure, that is, the shortest distance from the center of any first slot fracturing hole to the free surface is equal, and the minimum resistance line is equal. When the blasting stress wave reaches the free surface, it will be reflected into a tensile wave. The rock will be broken and thrown out under the combined action of shear force and tensile force, thereby forming a groove cavity of expected volume, creating a new free surface for the blasting of the lower section of rock, so that the blasting resistance of the lower section of rock is greatly reduced, thereby facilitating the crushing and throwing of the lower section of rock.

[0020] 4. The present invention first detonates the carbon dioxide fracturing device in the central fracturing hole and the carbon dioxide fracturing device in the first slot fracturing hole, and forms a sufficiently large slot cavity after blasting. When the carbon dioxide fracturing device in the second slot fracturing hole is detonated, the free surface is large enough, and the high-pressure gas released by the carbon dioxide fracturing device is sufficient to overcome the clamping force of the rock, thereby achieving a better blasting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of blasthole arrangement of the present invention;

[0022] Figure 2 A schematic diagram of an isosceles triangle formed by the central crack-inducing hole, two adjacent first cut-out crack-inducing holes and the empty hole of the present invention;

[0023] Figure 3A schematic diagram of the positional relationship between the central crack-inducing hole, two adjacent first cut-out crack-inducing holes and the empty hole of the present invention;

[0024] The reference numerals in the figure are as follows: 1-central crack-causing hole; 2-empty hole; 3-first circle of blast holes; 31-first groove-causing crack hole; 4-second circle of blast holes; 41-second groove-causing crack hole. DETAILED DESCRIPTION

[0025] See also Figure 1 The carbon dioxide fracturing device slotting structure of a hard rock tunnel comprises a central fracturing hole 1, an empty hole 2, a first circle of blast holes 3 and a second circle of blast holes 4; the central fracturing hole 1 is arranged along the axis of the tunnel, the empty hole 2 is arranged around the central fracturing hole 1, the first circle of blast holes 3 is arranged in the outer circle of the empty hole 2, and the second circle of blast holes 4 is arranged in the outer circle of the first circle of blast holes 3; the first circle of blast holes 3 is composed of first slotting fracturing holes 31, and the second circle of blast holes 4 is composed of second slotting fracturing holes 41. The diameters of the central fracturing hole 1, the empty hole 2, the first slotting fracturing hole 31 and the second slotting fracturing hole 41 are the same and are perpendicular to the working surface. The diameters of the central fracturing hole 1, the empty hole 2, the first slotting fracturing hole 31 and the second slotting fracturing hole 41 are in the range of 60-150 mm.

[0026] The hollow holes 2 are provided at the midpoints of the center connecting lines of any two adjacent first cutout crack-causing holes 31, and one hollow hole 2 is arranged on the radius extension line from any hollow hole 2 to the central crack-causing hole 1. The hollow holes 2 are arranged at equal intervals on the circumference of a circle with the central crack-causing hole 1 as the center. The number of the hollow holes 2 is four, and the four hollow holes 2 are arranged in a square. The centers of the four hollow holes 2 are respectively located at the vertices of the four corners of the square, and the center point of the square is circumferentially opposite to the circumference of the central crack-causing hole 1. The centers of the two adjacent holes 2 coincide with each other; the center distance between the two adjacent holes 2 is 600 mm, and there are two holes 2 between the central fracture hole 1 and each first groove fracture hole 31, and the holes 2 are free surfaces to ensure that the rock can be broken; when the blasting stress wave reaches the free surface, it will be reflected into a tensile wave. When the tensile wave is greater than the tensile strength of the rock, a Hawkinson effect will be generated to improve the blasting effect. At the same time, the reflected tensile wave and the stress field at the tip of the radial crack are superimposed on each other, which promotes the further expansion of the radial crack and the annular crack, greatly increasing the range of the crack zone.

[0027] A second grooved fracture hole 41 is arranged on the extension line of the radius from the central fracture hole 1 to any one of the empty holes 2; a second grooved fracture hole 41 is also arranged on the extension line of the radius from the central fracture hole 1 to any one of the first grooved fracture holes 31, and a second grooved fracture hole 41 is arranged on the extension line of the radius from any one of the second grooved fracture holes 41 to the central fracture hole 1. The second grooved fracture holes 41 are arranged at equal intervals on the circumference with the central fracture hole 1 as the center. The first circle of blast holes 3 includes four first grooved fracture holes 31, and the second circle of blast holes 4 includes eight second grooved fracture holes 41. The center distance between the first grooved fracture hole 31 and the central fracture hole 1 is 600 mm.

[0028] The empty hole 2 is provided at the midpoint of the center connection line of any two adjacent first grooved crack holes 31; a second grooved crack hole 41 is arranged on the extension line of the radius from the central crack hole 1 to any one of the empty holes 2; a second grooved crack hole 41 is also arranged on the extension line of the radius from the central crack hole 1 to any one of the first grooved crack holes 31; a empty hole 2 is arranged on the extension line of the radius from any one of the empty holes 2 to the central crack hole 1; a second grooved crack hole 41 is arranged on the extension line of the radius from any one of the second grooved crack holes 41 to the central crack hole 1; the empty holes 2 are arranged at equal intervals on the circumference with the central crack hole 1 as the center; the second grooved crack holes 41 are arranged at equal intervals on the circumference with the central crack hole 1 as the center, such as Figure 2 As shown, the center point of the central crack hole 1 and the connecting line of the center points of any two adjacent first cut crack holes 31 form an isosceles triangle, and an empty hole 2 is set in the middle of any one of the isosceles triangles; Figure 3As shown, in any isosceles triangle: the distance between the center of the empty hole 2 and the central fracture hole 1 is equal to the distance between the center of any one of the two adjacent first groove fracture holes 31 and the empty hole 2, the distance between the center of the second groove fracture hole 41 and the central fracture hole 1 is 1000 mm, the central fracture hole 1 and the two adjacent first groove fracture holes 31 in the adjacent first circle of blast holes 3 form an isosceles triangle, and the rock between the central fracture hole 1 and the two first groove fracture holes 31 is formed under high pressure carbon dioxide gas. Stress superposition will occur under the action of the body, and the triangular arrangement of the fracturing holes makes the rock more susceptible to shear failure, that is, the shortest distance from the center of any first slot fracturing hole 31 to the free surface is equal, and the minimum resistance line is equal. When the blasting stress wave reaches the free surface, it will be reflected into a tensile wave. The rock is broken and thrown out under the combined action of shear force and tensile force, thereby forming a groove cavity of the expected volume, creating a new free surface for the blasting of the lower section of rock, which greatly reduces the blasting resistance of the lower section of rock, thereby facilitating the crushing and throwing of the lower section of rock.

[0029] A carbon dioxide fracturing device slotting blasting method for a hard rock tunnel comprises the following steps:

[0030] Step A: inserting carbon dioxide fracturing devices into the central fracturing hole 1, the first cutout fracturing hole 31 of the first circle of blast holes 3, and the second cutout fracturing holes 41 of the second circle of blast holes 4, respectively, and the empty hole 2 is an empty hole;

[0031] Step B: First, the carbon dioxide fracturing device in the central fracturing hole 1 and the carbon dioxide fracturing device in the first slot fracturing hole 31 are detonated simultaneously, and then the carbon dioxide fracturing device in the second slot fracturing hole 41 is detonated; the carbon dioxide fracturing device in the central fracturing hole 1 and the carbon dioxide fracturing device in the first slot fracturing hole 31 are detonated simultaneously, and under the action of the multi-directional blasting inside and outside, the rock is fully squeezed and crushed, and the rock crushing effect is better than that of the central hole being a simple empty hole 2; the carbon dioxide fracturing device in the central fracturing hole 1 and the carbon dioxide fracturing device in the first slot fracturing hole 31 are detonated first, and a sufficiently large groove cavity is formed after blasting. When the carbon dioxide fracturing device in the second slot fracturing hole 41 is detonated, the free surface is large enough, and the high-pressure gas released by the carbon dioxide fracturing device is sufficient to overcome the clamping force of the rock, thereby achieving a better blasting effect.

[0032] Workflow: a vertical central fracturing hole 1 is opened on the working surface line, and empty holes 2 are set around the central fracturing hole 1 with the center of the central fracturing hole 1 as the center. The empty holes 2 are arranged in a square, and the center distance between the empty holes 2 is 600 mm, so that the center point of the square formed by four empty holes 2 coincides with the center of the central fracturing hole 1, four first slot fracturing holes 31 are opened around the central fracturing hole 1 at a center distance of 600 mm, and a corresponding number of second slot fracturing holes 41 are opened around the central fracturing hole 1 at a center distance of 1000 mm, and the positions of the empty holes 2, the first slot fracturing holes 31 and the second slot fracturing holes 41 meet the requirements, and the blasthole arrangement is completed; a carbon dioxide fracturing device is placed in the first slot fracturing hole 31, the second slot fracturing hole 41 and the central fracturing hole 1, and the carbon dioxide fracturing devices in the central fracturing hole 1 and the first slot fracturing hole 31 are first detonated simultaneously, and then the carbon dioxide fracturing device in the second slot fracturing hole 41 is detonated, and the blasting construction is completed.

[0033] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A carbon dioxide fracturing device for a hard rock tunnel, characterized in that: The tunnel comprises a central fracture-inducing hole (1), an empty hole (2), a first circle of blast holes (3) and a second circle of blast holes (4); the central fracture-inducing hole (1) is arranged along the tunnel axis, the empty hole (2) is arranged around the central fracture-inducing hole (1), the first circle of blast holes (3) is arranged on the outer circle of the empty hole (2), and the second circle of blast holes (4) is arranged on the outer circle of the first circle of blast holes (3); the first circle of blast holes (3) is composed of first groove-cut fracture-inducing holes (31), and the second circle of blast holes (4) is composed of second groove-cut fracture-inducing holes (41); The center point of the central crack-inducing hole (1) and the connecting line of the center points of any two adjacent first groove crack-inducing holes (31) form an isosceles triangle, and a hollow hole (2) is arranged in the middle of any one of the isosceles triangles; in any one of the isosceles triangles: the distance between the center points of the hollow hole (2) and the central crack-inducing hole (1) is equal to the distance between the center points of any one of the two adjacent first groove crack-inducing holes (31) and the hollow hole (2); the diameters of the central crack-inducing hole (1), the hollow hole (2), the first groove crack-inducing hole (31) and the second groove crack-inducing hole (41) are the same and are perpendicular to the working surface; the central crack-inducing hole (1), the hollow hole (2), the first groove crack-inducing hole (31) and the second groove crack-inducing hole (41) are equal to the diameters of the central crack-inducing hole (1), the hollow hole (2), the first groove crack-inducing hole (31) and the second groove crack-inducing hole (41) The diameters of the first grooved crack-inducing holes (31) and the second grooved crack-inducing holes (41) are in the range of 60-150 mm; the number of the empty holes (2) is four, the four empty holes (2) are arranged in a square, the centers of the four empty holes (2) are respectively located at the vertices of the four corners of the square, and the center point of the square coincides with the center of the center crack-inducing hole (1); the center distance between two adjacent empty holes (2) is 600 mm; the first circle of blast holes (3) includes four first grooved crack-inducing holes (31), and the second circle of blast holes (4) includes eight second grooved crack-inducing holes (41), the center distance between the first grooved crack-inducing holes (31) and the center crack-inducing hole (1) is 600 mm, and the center distance between the second grooved crack-inducing holes (41) and the center crack-inducing hole (1) is 1000 mm; the second grooved crack-inducing holes (41) are arranged at equal intervals on a circle with the center crack-inducing hole (1) as the center.

2. The carbon dioxide fracturing device for hard rock tunnel according to claim 1 is characterized in that: A second grooved fracture hole (41) is arranged on an extension line of a radius from the central fracture hole (1) to any one of the empty holes (2); and a second grooved fracture hole (41) is also arranged on an extension line of a radius from the central fracture hole (1) to any one of the first grooved fracture holes (31).

3. The carbon dioxide fracturing device for hard rock tunnel according to claim 2 is characterized in that: A second notch-inducing crack hole (41) is arranged on an extension line of a radius from any one of the second notch-inducing crack holes (41) to the central crack hole (1).

4. The blasting method for a carbon dioxide fracturing device cutout structure in a hard rock tunnel according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step A: Carbon dioxide fracturing devices are respectively installed into the central fracturing hole (1), the first grooved fracturing hole (31) of the first circle of blast holes (3), and the second grooved fracturing hole (41) of the second circle of blast holes (4), and the empty hole (2) is an empty hole; Step B: First, the carbon dioxide fracturing device in the central fracturing hole (1) and the carbon dioxide fracturing device in the first grooved fracturing hole (31) are simultaneously detonated, and then the carbon dioxide fracturing device in the second grooved fracturing hole (41) is detonated.

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