A forward and reverse wedge-shaped slotting blasting excavation construction method

Abstract

This invention discloses a method for positive-reverse wedge-shaped slotting blasting excavation, relating to the field of drill-and-blast rock tunneling technology. It includes: arranging a first set of slotting holes, a second set of slotting holes, and a central hole group below the intersection of the tunnel's arching line and center line; the first and second sets of slotting holes are respectively located on both sides of the central hole group, and each set includes: a positive wedge-shaped slotting hole group, a reverse wedge-shaped slotting hole group, and an auxiliary slotting hole group. The reverse wedge-shaped slotting hole group and the auxiliary slotting hole group are arranged on both sides of the positive wedge-shaped slotting hole group, with the reverse wedge-shaped slotting hole group adjacent to the central hole group. Each central hole is perpendicular to the working face, and the positive and reverse wedge-shaped slotting holes are obliquely intersecting the working face, and are laterally staggered. This invention is beneficial for improving the utilization rate of blast holes, thereby improving the efficiency of blasting excavation; it is applicable to blasting excavation operations in tunnels, roadways, and other similar projects.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of drill-and-blast rock drivage technology, and particularly relates to a positive-negative wedge-shaped cut blasting drivage construction method. BACKGROUND

[0002] The development of rock drivage construction technology is crucial to the improvement of rock drivage level and the alleviation of mining and excavation contradiction. Currently, 90% of rock drivages are constructed by drill-and-blast method, and the rock drivage level by drill-and-blast method has been hovering at about 70m / month for a long time, which leads to mining and excavation imbalance and seriously restricts the production connection of coal mines. As the most important part of rock drivage by drill-and-blast method, cut technology is significantly strengthened by the increasing depth of blast hole under hard rock conditions, which leads to low blasting efficiency and cannot meet the design requirements of blast hole utilization rate.

[0003] The cut technology is generally divided into two categories: inclined hole cut and straight hole cut, which can be further divided into the following types: wedge cut, conical cut, wedge-straight composite cut, diamond cut, triangular prism cut, quadrangular prism cut, five-star cut, hexagonal prism cut, and spiral cut.

[0004] The inclined hole cut is characterized by the oblique intersection of the cut hole and the free surface, and the commonly used wedge cut is adopted. The main feature of this cut is to take the working face as the free surface, and the cut holes are simultaneously blasted. After the initiation of the explosive, the rock in the wedge-shaped area is broken under the combined action of stress wave and detonation gas. Under good plugging conditions, the broken rock in the wedge-shaped area is thrown out due to the long-time high-pressure state of the detonation gas in the blast hole, forming a cut cavity to achieve the purpose of cut.

[0005] The straight hole cut is characterized by the blasting of the empty hole as the main free surface, and its minimum resistance line is the distance from the charging hole to the empty hole. Because the cut holes are parallel to each other, the minimum resistance line from the hole to the bottom of the hole is the same, forming a regular cut cavity.

[0006] The inventor found in the process of realizing the present application that the straight hole cut has high requirements for the distance of the blast holes, and the number of blast holes in the cut area is large, resulting in long rock drilling operation time. The wedge cut has the blast hole arrangement as shown in FIGS. 1 and 2, and the distance between the cut hole openings at the head is large after the initiation of the holes 4 to 12, forming a wedge-shaped cut cavity that is wide at the top and narrow at the bottom, as shown in FIG. 3. The characteristics of this type of cut cavity result in the distance between the blast holes, such as holes 13-18, being only about 300mm, but the distance between the bottom of the blast hole and the cut cavity is 2-3 times the distance between the hole openings, which is 340mm, as shown in FIG. 4, i.e., 867mm, resulting in an excessively large minimum resistance line at the bottom of the blast hole, as shown in FIG. 5. Figure 1 Figure 2 Figure 3 Figure 3 Figure 4 ​​​​As shown, the eye bottom is seriously left after blasting, and the utilization rate of blast hole is not high, which affects the blasting driving efficiency. SUMMARY

[0007] Therefore, the embodiment of the present application provides a positive-negative wedge cut blasting driving construction method, which is beneficial to improve the utilization rate of blast hole and the efficiency of blasting driving.

[0008] To achieve the above object, the embodiment of the present application adopts the following technical scheme:

[0009] A positive-negative wedge cut blasting driving construction method comprises the following steps:

[0010] S10, arranging a first group of cut holes, a second group of cut holes and a center hole group below the intersection point of the arch line and the center line of the roadway; the first group of cut holes and the second group of cut holes are arranged on the two sides of the center hole group, the first group of cut holes and the second group of cut holes respectively comprise a positive wedge cut hole group, a negative wedge cut hole group and an auxiliary cut hole group, the negative wedge cut hole group and the auxiliary cut hole group are arranged on the two sides of the positive wedge cut hole group, the negative wedge cut hole group is arranged adjacent to the center hole group, each center hole of the center hole group is arranged vertically to the working face, the positive wedge cut hole group comprises a plurality of positive wedge cut holes, the negative wedge cut hole group comprises a plurality of negative wedge cut holes, the positive wedge cut hole and the negative wedge cut hole are respectively inclined to the working face, and the positive wedge cut hole and the negative wedge cut hole are arranged laterally staggered;

[0011] S20, after the center hole group, the first group of cut holes and the second group of cut holes are arranged, charging the blast hole of the center hole group, the first group of cut holes and the second group of cut holes respectively; wherein the length of the charge is less than the depth of the blast hole.

[0012] S30, after the charging is completed, detonating the center hole group, the first group of cut holes and the second group of cut holes.

[0013] Optionally, the positive wedge cut hole group comprises 3n positive wedge cut holes, the negative wedge cut hole group comprises 2n negative wedge cut holes, the auxiliary cut hole group comprises 2n straight cut holes, n is a positive integer, the center line of the positive wedge cut hole is inclined to the working face to form a first included angle, the negative wedge cut hole is inclined to the working face to form a second included angle, the opening of the first included angle and the second included angle is on the same side, and the first included angle and the second included angle are complementary.

[0014] Optionally, in step S20, the charging of the blast hole of the center hole group, the first group of cut holes and the second group of cut holes respectively comprises the following steps:

[0015] S21a, using axial segmented charging mode to at least two uncoupled charges in the holes of the center hole group, the positive wedge-shaped cut hole group and the negative wedge-shaped cut hole group, and at least one charge in the holes of the auxiliary cut hole group;

[0016] In step S30, the initiation of the center hole group, the first group of cut holes and the second group of cut holes includes:

[0017] S31a, using 1 section detonator to initiate the first section of the charge in each hole of the positive wedge-shaped cut hole group and the negative wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes;

[0018] S32a, using 2 section detonator to initiate the first section of the charge in each hole of the center hole group after a first predetermined delay time;

[0019] S33a, using 3 section detonator to initiate the second section of the charge in each hole of the positive wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a second predetermined delay time;

[0020] S34a, using 4 section detonator to initiate the second section of the charge in each hole of the center hole group and the second section of the charge in each hole of the positive wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a third predetermined delay time; wherein the position of the first section of the charge in the hole is closer to the hole mouth relative to the second section of the charge;

[0021] S35a, using 5 section detonator to initiate the charge in each hole of the auxiliary cut hole group of the first group of cut holes and the second group of cut holes after a fourth predetermined delay time, for trimming the cut cavity formed after the blasting of the foregoing steps to form a regular cut cavity.

[0022] Optionally, the length of the first section of the charge in each hole of the positive wedge-shaped cut hole group, the negative wedge-shaped cut hole group and the center hole group is greater than or equal to L / 4 and less than L / 2;

[0023] The length of the second section of the charge in each hole of the positive wedge-shaped cut hole group, the negative wedge-shaped cut hole group and the center hole group is greater than or equal to L / 3+0.3m and less than L / 2;

[0024] The position of the charge in the hole of the auxiliary cut hole group corresponds to the position of the second section of the charge, which is located within the cross section of the hole; wherein the hole depth of each hole is greater than the to-be-cut depth L, and the over-depth of each hole decreases from the center of the cut area to both sides in a gradient, and the inner end of the second section of the charge and the charge in the hole of the auxiliary cut hole group abuts the hole bottom, respectively.

[0025] Optionally, in step S20, the charging of the blast holes of the center hole group, the first group of cut holes and the second group of cut holes includes the steps of:

[0026] S21b, at least two uncoupled charges are loaded into the holes of the center hole group and the anti-wedge cut hole group by using axial segmented charging mode, and at least one charge is loaded into the holes of the positive wedge cut hole group and the auxiliary cut hole group;

[0027] In step S30, the initiation of the center hole group, the first group of cut holes and the second group of cut holes includes:

[0028] S31b, the first segment of the charge in each hole of the center hole group, the anti-wedge cut hole group of the first group of cut holes and the second group of cut holes is initiated by using a 1-segment detonator;

[0029] S32b, the charge in each hole of the positive wedge cut hole group of the first group of cut holes and the second group of cut holes is initiated by using a 2-segment detonator after a first predetermined delay time;

[0030] S33b, the second segment of the charge in each hole of the center hole group and the anti-wedge cut hole group of the first group of cut holes and the second group of cut holes is initiated by using a 3-segment detonator after a second predetermined delay time;

[0031] S34b, the charge in each hole of the auxiliary cut hole group of the first group of cut holes and the second group of cut holes is initiated by using a 4-segment detonator after a third predetermined delay time, which is used to trim the cut cavity formed after the blasting in the foregoing steps to form a regular cut cavity.

[0032] Optionally, the first segment of the charge in the anti-wedge cut hole has a length of L / 3 and the second segment of the charge has a length of L / 3+d, d is the overlength of the cut hole, and the first segment of the charge and the second segment of the charge are blocked by stemming;

[0033] The length of the charge in the positive wedge cut hole is L / 2+d, and the remaining part is filled with stemming.

[0034] Optionally, the center hole group is longitudinally arranged with three center holes, from top to bottom, the first center hole, the second center hole and the third center hole, the positive wedge cut hole group is longitudinally arranged with four positive wedge cut holes, from top to bottom, the first positive wedge cut hole, the second positive wedge cut hole, the third positive wedge cut hole and the fourth positive wedge cut hole, and the anti-wedge cut hole group is longitudinally arranged with three anti-wedge cut holes, from top to bottom, the first anti-wedge cut hole, the second anti-wedge cut hole and the third anti-wedge cut hole;

[0035] The first segment of the charge in the first center hole uses a shaped charge, and the shaped direction of the shaped charge faces the second center hole, the first group of cut holes and the first anti-wedge cut hole of the second group of cut holes;

[0036] The first section of the second central hole adopts a shaped charge, and the shaped charge cut seam direction is respectively towards the first central hole, the third central hole, the first group of cut holes and the second anti-wedge cut hole of the second group of cut holes;

[0037] The first section of the third central hole adopts a shaped charge, and the shaped charge cut seam direction is respectively towards the second central hole, the first group of cut holes and the third anti-wedge cut hole of the second group of cut holes;

[0038] The second section of the hole, the positive wedge cut hole and the hole in the auxiliary cut hole are ordinary holes.

[0039] Optionally, the anti-wedge cut hole is perpendicular to the working face, the first group of cut holes and the second group of cut holes respectively further include a straight cut hole group, the straight cut hole group is arranged between the anti-wedge cut hole group and the central hole group, the depth of the cut hole of the straight cut hole group is 3L / 8, and L is the depth to be cut;

[0040] In step S20, the hole in the central hole group, the first group of cut holes and the second group of cut holes is charged, including the steps of:

[0041] S21c, at least two uncoupled charges are charged into the holes of the anti-wedge cut hole group by using an axial segmented charging method, at least one section of the hole in the positive wedge cut hole group, the straight cut hole group and the auxiliary cut hole group is charged, and the hole in the central hole group is reserved as a hole; the length of the charge in the hole of the straight cut hole group is 3L / 16, and the length of the second charge in the anti-wedge cut hole is 3L / 8;

[0042] In step S30, the central hole group, the first group of cut holes and the second group of cut holes are initiated, including:

[0043] S31c, a 1-section detonator is used to initiate the hole in the straight cut hole group;

[0044] S32c, a 2-section detonator is used to initiate the first section of the hole in the anti-wedge cut hole group of the first group of cut holes and the second group of cut holes after a first predetermined delay time;

[0045] S33c, a 3-section detonator is used to initiate the hole in the positive wedge cut hole group of the first group of cut holes and the second group of cut holes after a second predetermined delay time;

[0046] S34c, a 4-section detonator is used to initiate the second section of the hole in the anti-wedge cut hole group of the first group of cut holes and the second group of cut holes after a third predetermined delay time; wherein the position of the first section of the hole in the hole is close to the hole relative to the second section of the hole.

[0047] S35c, using 5-stage detonator, after the fourth predetermined delay time, detonating the charge in each hole of the first group of cut holes and the auxiliary cut hole group of the second group of cut holes, for trimming the cut cavity formed after the blasting of the foregoing steps, to form a regular cut cavity.

[0048] Optionally, the positive wedge cut hole and the negative wedge cut hole are used to form a small cut, three adjacent blast holes constitute a cut hole group, forming an equilateral triangle on the roadway section, and two blast holes adjacent to each other constitute a pair of cut holes, the three blast holes of the small cut hole group, i.e. the three blast holes of a cut hole group, intersect at the same line on the bottom of the small cut hole, and the projection of the line on the roadway section passes through the centroid of the three triangles.

[0049] The positive-negative wedge cut blasting excavation construction method provided by the embodiment of the present application arranges a first group of cut holes, a second group of cut holes and a central hole group below the intersection point of the arch line and the center line of the roadway; the first group of cut holes and the second group of cut holes are arranged on the two sides of the central hole group, the first group of cut holes and the second group of cut holes respectively include a positive wedge cut hole group, a negative wedge cut hole group and an auxiliary cut hole group, the negative wedge cut hole group and the auxiliary cut hole group are arranged on the two sides of the positive wedge cut hole group, and the negative wedge cut hole group is arranged adjacent to the central hole group, each central hole of the central hole group is arranged vertically to the working face, the positive wedge cut hole group includes a plurality of positive wedge cut holes, the negative wedge cut hole group includes a plurality of negative wedge cut holes, the positive wedge cut hole and the negative wedge cut hole are respectively inclined to the working face, and the positive wedge cut hole and the negative wedge cut hole are arranged laterally staggered. In this way, the negative wedge cut hole and the positive wedge cut hole cooperate with each other, and when detonated, they can form large and small cuts, deep and shallow cuts, which can play an advantage, the small cut creates a larger free surface for the large cut, and the deep hole cut is changed into a shallow partial layer cut, which is beneficial to reduce the clamping effect of the rock roadway cut blasting and improve the utilization rate of the blast hole, thereby improving the blasting excavation efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0051] Figure 1 It is a front view of the cut hole arrangement of the existing wedge cut blasting excavation technology;

[0052] Figure 2 It is a sectional view of the cut hole arrangement of the existing wedge cut blasting excavation technology;

[0053] Figure 3 For Figure 1 The existing wedge slotting blasting excavation technology in the middle of the hole 4 to 12 slotting effect diagram after blasting;

[0054] Figure 4 For Figure 1 The existing wedge slotting blasting excavation technology in the middle of all holes after blasting to form slotting cavity effect diagram;

[0055] Figure 5a And Figure 5b For the embodiment of the present invention, the main view of the slotting hole layout of the working face to be excavated in the positive-negative wedge slotting blasting excavation construction method;

[0056] Figure 6 For Figure 5a Or Figure 5b The cross-sectional view and charging diagram of the slotting hole layout in the embodiment;

[0057] Figures 7 to 11 For Figure 6 The slotting hole delay detonation process schematic diagram in the embodiment;

[0058] Figure 12 For another embodiment of the present invention, the main view of the slotting hole layout of the working face to be excavated in the positive-negative wedge slotting blasting excavation construction method;

[0059] Figure 13 For Figure 12 The cross-sectional view and charging diagram of the slotting hole layout in the embodiment;

[0060] Figure 14 For another embodiment of the present invention, the main view of the slotting hole layout of the working face to be excavated in the positive-negative wedge slotting blasting excavation construction method;

[0061] Figure 15 For Figure 14 The cross-sectional view and charging diagram of the slotting hole layout in the embodiment. DETAILED DESCRIPTION

[0062] The positive-negative wedge slotting blasting excavation construction method provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0063] It should be clear that the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0064] Referring to Figures 5a to 15As shown, the positive-negative wedge-shaped compound slotting blasting tunneling construction method provided in this embodiment of the invention is mainly applicable to rock drilling operations, tunnels, roadways and blasting tunneling engineering operations in mines; hard rock roadways specifically refer to rock roadways with a rock firmness coefficient (Protodyakonov coefficient) f greater than or equal to 7, and also include roadways that belong to hard rock as determined by other arbitrary surrounding rock classification methods.

[0065] like Figures 5a to 6 As shown, this embodiment of the invention provides a method for positive-negative wedge-shaped compound cut-and-blast tunneling, including the following steps:

[0066] S10. Arrange the first set of slotting holes, the second set of slotting holes, and the center hole group below the intersection of the tunnel arch line and the center line.

[0067] The first group of slotted holes and the second group of slotted holes are respectively located on both sides of the central hole group. The first group of slotted holes and the second group of slotted holes respectively include: a positive wedge slotted hole group, a negative wedge slotted hole group and an auxiliary slotted hole group. The negative wedge slotted hole group and the auxiliary slotted hole group are arranged on both sides of the positive wedge slotted hole group, and the negative wedge slotted hole group is arranged adjacent to the central hole group. Each central hole of the central hole group is perpendicular to the working surface. The positive wedge slotted hole group includes multiple positive wedge slotted holes, and the negative wedge slotted hole group includes multiple negative wedge slotted holes. The positive wedge slotted holes and the negative wedge slotted holes are oblique to the working surface, and the positive wedge slotted holes and the negative wedge slotted holes are laterally staggered.

[0068] The terms "positive wedge cut hole" and "reverse wedge cut hole" refer to the inclination direction of the borehole. A positive wedge cut hole is one where the borehole drilling direction gradually moves towards the center line of the cut area. A reverse wedge cut hole is one where the borehole drilling direction gradually moves away from the center line.

[0069] For example, such as Figure 5b and Figure 6 As shown, the positive wedge-shaped cut holes include holes 8 to 13; the negative wedge-shaped cut holes include holes 4 to 7; and the center hole includes holes 1 to 3. This positive and negative wedge-shaped compound cut hole structure forms a cut structure with localized small cuts and an overall large cut after detonation. Specifically, as shown... Figures 5a to 6 As shown. The localized small cuts are only the outer part of the cut holes 4-13 near the free surface, and the first hole sections of holes 4, 5, 11-13 and holes 6, 7, 8-10 ( Figure 6 The external portion (as shown) forms zigzag-shaped grooves, symmetrical on both sides, as... Figure 5b As shown.

[0070] in, Figure 6 The boundary between the inner and outer sides of the borehole is shown at L / 2, and the starting point of the explosive position in the two sets of small slots is at the boundary line.

[0071] In some embodiments, the set of positive wedge-shaped cutting holes comprises 3n positive wedge-shaped cutting holes, the set of negative wedge-shaped cutting holes comprises 2n negative wedge-shaped cutting holes, and the set of auxiliary cutting holes comprises 2n auxiliary straight cutting holes, the cutting holes are generally designed in pairs, n is a positive integer, and an example is shown in FIG. 1, in which n is 2, and the set of auxiliary straight cutting holes comprises holes 14 to 17. Figure 1 The center line of the positive wedge-shaped cutting hole forms a first included angle with the working face, the negative wedge-shaped cutting hole forms a second included angle with the working face, the openings of the first included angle and the second included angle are on the same side, and the first included angle and the second included angle are complementary.

[0072] An example is shown in FIG. 1. Figure 5b and Figure 6 The center hole is arranged perpendicular to the working face, the positive wedge-shaped cutting hole is oblique to the working face at an angle of generally between 70 and 80 degrees, and the negative wedge-shaped cutting hole is oblique to the working face at an angle of 100 to 110 degrees, that is, assuming that the angle of the main wedge-shaped cutting hole is α, the angle of the negative wedge-shaped cutting hole with the working face is 180-α, and the angles of the two are complementary.

[0073] Figure 5b As shown in FIG. 1, the positive wedge-shaped cutting hole and the negative wedge-shaped cutting hole are used to form a small cutting hole, three adjacent blast holes constitute a cutting hole group, and an equilateral triangle is formed on the roadway section (i.e., arranged in an equilateral triangle), two blast holes adjacent to each other constitute a pair of cutting holes, and the drilling directions of the three blast holes of the small cutting hole group, i.e., the three blast holes of the cutting hole group, meet on the same line at the bottom of the small cutting hole, and the projection of the line on the tunnel section passes through Figure 5b the centroid of the triangle shown in FIG. 1.

[0074] S20, after the center hole group, the first group of cutting holes, and the second group of cutting holes are arranged, charging is performed in the blast holes of the center hole group, the first group of cutting holes, and the second group of cutting holes; wherein the length of the charge is less than the depth of the blast hole.

[0075] S30, after the charging is completed, the center hole group, the first group of cutting holes, and the second group of cutting holes are detonated.

[0076] The positive-negative wedge-shaped slotting blasting excavation construction method provided by the embodiment of the present application is characterized in that: a first group of slotting holes, a second group of slotting holes and a central hole group are arranged below the intersection of the arch line and the center line of the roadway; the first group of slotting holes and the second group of slotting holes are arranged on the two sides of the central hole group, and the first group of slotting holes and the second group of slotting holes each include a positive wedge-shaped slotting hole group, a negative wedge-shaped slotting hole group and an auxiliary slotting hole group; the negative wedge-shaped slotting hole group and the auxiliary slotting hole group are arranged on the two sides of the positive wedge-shaped slotting hole group, and the negative wedge-shaped slotting hole group is arranged adjacent to the central hole group; each central hole of the central hole group is arranged vertically to the working face; the positive wedge-shaped slotting hole group includes a plurality of positive wedge-shaped slotting holes; the negative wedge-shaped slotting hole group includes a plurality of negative wedge-shaped slotting holes; the positive wedge-shaped slotting holes and the negative wedge-shaped slotting holes are each obliquely intersected with the working face, and the positive wedge-shaped slotting holes and the negative wedge-shaped slotting holes are arranged laterally staggered. In this way, the negative wedge-shaped slotting holes and the positive wedge-shaped slotting holes cooperate with each other, and when detonated, the small slotting holes and the deep and shallow slotting holes can be combined to play the advantages, the small slotting holes create a larger free surface for the large slotting holes, and the deep slotting holes are changed into shallow partial layer slotting holes, which is beneficial to reduce the clamping effect of the surrounding rock of the rock roadway on the slotting blasting and improve the utilization rate of the blast holes, so as to improve the blasting excavation efficiency.

[0077] As shown in Figure 5b and 6 , the positive and negative wedge-shaped complex slotting holes are each composed of 3 central holes, 3 pairs of slotting holes and 2 pairs of auxiliary slotting holes. Taking a 2.6 m scheme as an example, the depth of the slotting holes is L=2.6 m, the depth of the positive wedge-shaped slotting holes is Lpositive=L+0.3 m=2.9 m, the depth of the negative wedge-shaped slotting holes is Lnegative=L+0.3 m=2.9 m, the depth of the central holes is 2.9 m, the distance between the slotting holes is not greater than 500 mm, generally 400 mm, the length of b is not less than 600 mm, generally 800-1000 mm. The length of a is generally 300-500 mm, and the length of a' is generally 200-400 mm. The slotting angles 1-3 are 90°, the positive wedge-shaped slotting holes 8-13 are 78°, and the negative wedge-shaped slotting holes 4-7 are 102°.

[0078] As an optional embodiment, in step S20, the charging of the blast holes in the central hole group, the first group of slotting holes and the second group of slotting holes respectively includes the following steps:

[0079] S21a, the axial segmented charging mode is used to charge at least two uncoupled charges in the holes of the central hole group, the positive wedge-shaped slotting hole group and the negative wedge-shaped slotting hole group, and at least one charge is charged into the hole of the auxiliary slotting hole group; wherein, 1-2 charges close to the hole mouth are shaped charges with the energy gathering direction towards the fold line, or large diameter charges relative to other charges.

[0080] For the convenience of description, the first section of the cartridge is the cartridge in the outer hole section in the illustrated orientation, and the second section of the cartridge is the cartridge in the inner hole section in the illustrated orientation; a cartridge is loaded, and if no specific description is given, it is the cartridge in the inner hole section in the illustrated orientation, wherein the boundary between the inner side and the outer side is at L / 2, as shown in Figure 5b The starting point of the first section of the cartridge is at the boundary.

[0081] In step S30, the initiation of the central hole group, the first group of cut holes, and the second group of cut holes includes:

[0082] S31a, using a 1-section detonator to initiate the first section of the cartridge in each hole of the first group of cut holes and the positive and negative wedge-shaped cut hole groups of the second group of cut holes, that is, Figure 6 The cartridges loaded on the outer side in the middle holes 4-13 (lower part in the illustrated orientation) have the slot cavity effect (horizontal section) after initiation as shown, Figure 7 Forming a local small cut, which, from the perspective of the cut space, is like Figure 5b The dashed line connecting the two is a 'isosceles trapezoid' shaped broken line slot cavity.

[0083] By using the spatial interval arrangement of the positive and negative wedge-shaped cut hole groups, the holes are drilled in opposite directions, and after initiation, two small cuts are formed first, providing more free surfaces for the central hole group blasting, and then using the central hole group blasting, the upper rock can be more easily collapsed, forming a larger shallow cut.

[0084] S32a, using a 2-section detonator to initiate the first section of the cartridge in each hole of the central hole group after a first predetermined delay time, that is, Figure 6 The cartridges loaded on the outer side in the middle holes 1-3 (lower part in the illustrated orientation); the effect after initiation is as shown, Figure 8 Forming a shallow large cut through the left and right small cuts, changing the deep hole blasting to shallow hole blasting, reducing the clamping effect of the surrounding rock, and improving the utilization rate of the blast hole. The first predetermined delay time can be a delay of 10 ms.

[0085] S33a, using a 3-section detonator to initiate the second section of the cartridge in each hole of the positive wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a second predetermined delay time; the wedge-shaped slot cavity effect after initiation is as shown. Figure 9 The second predetermined delay time can be a delay of 25 ms.

[0086] S34a, using a 4-section detonator to initiate the second section of the cartridge in each hole of the central hole group and the second section of the cartridge in each hole of the negative wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a third predetermined delay time; wherein the position of the first section of the cartridge in the hole is closer to the hole mouth relative to the second section of the cartridge. After this initiation, a broken line shaped cut is formed, which is symmetrical on both sides, and the effect is as shown. Figure 10The third predetermined delay time can be 35 ms.

[0087] S35a, using a 5-section detonator, after a fourth predetermined delay time, detonate the second section of the charge in each hole of the first group of cut holes and the second group of cut holes, which are auxiliary cut hole groups, for trimming the cut cavity formed after the blasting of the previous steps to form a regular cut cavity. Figure 11 The fourth predetermined delay time can be 55 ms.

[0088] From Figure 11 and Figure 4 It can be seen from the comparison that after the rock roadway working face blasting provided by the above method steps in the embodiment, compared with the slot cavity after the blasting of the existing cut scheme (see Figure 4 The effect shown in the figure), the problem of excessive resistance distance at the bottom of the subsequent blast hole after wedge cut blasting is solved, the resistance lines at the bottom of the cut holes tend to be the same, the problem of leaving the bottom is solved, which is conducive to the improvement of the utilization rate of the blast hole.

[0089] In other embodiments, which are basically the same as the embodiments of the previous step 30, the difference is that step S34a can be implemented in two steps, specifically: step 34a1, using a 4-section detonator, after a third predetermined delay time, detonate the second section of the charge in each hole of the center hole group; that is, the lower blast holes of holes 1 to 3 in the figure are detonated with a delay of 35 ms.

[0090] Step 34a2, using a 5-section detonator, after a fourth predetermined delay time, detonate the second section of the charge in each hole of the first group of cut holes and the second group of cut holes, which are anti-wedge cut hole groups. That is, the lower holes 4-7 in the figure are detonated with a delay of 55 ms.

[0091] Correspondingly, step S35a is replaced by: using a 6-section detonator, after a fifth predetermined delay time, detonate the charge in each hole of the first group of cut holes and the second group of cut holes, which are auxiliary cut hole groups, for trimming the cut cavity formed after the blasting of the previous steps to form a regular cut cavity. That is, the last blast holes 14-17 are detonated with a delay of 75 ms.

[0092] The length of the first section of the charge in each hole of the positive wedge cut hole group, the anti-wedge cut hole group and the center hole group is greater than or equal to L / 4 and less than L / 2; the length of the second section of the charge in each hole of the positive wedge cut hole group, the anti-wedge cut hole group and the center hole group is greater than or equal to L / 3+0.3m and less than L / 2.

[0093] The position of the charge in the hole of the auxiliary cut hole group corresponds to the position of the second section of the charge, which is inside the cross section of the hole; wherein the hole depth of each hole is greater than the cut depth L, and the over-depth of each hole decreases from the center of the cut area to both sides in a gradient, and the inner end of the second section of the charge and the charge in the hole of the auxiliary cut hole group abuts the hole bottom.

[0094] In yet some embodiments of the present application, based on the same technical concept as the foregoing embodiments, the difference is that, as shown in Figure 12 and Figure 13 shown, in step S20, the hole charging in the center hole group, the first group of cut holes and the second group of cut holes comprises the steps of:

[0095] S21b, at least two uncoupled charges are charged into the holes of the center hole group and the anti-wedge cut hole group by using axial segmented charging, and at least one charge is charged into the holes of the positive wedge cut hole group and the auxiliary cut hole group.

[0096] In step S30, the blasting of the center hole group, the first group of cut holes and the second group of cut holes comprises:

[0097] S31b, the first segment of charge in each hole of the center hole group, the anti-wedge cut hole group of the first group of cut holes and the second group of cut holes is initiated by using a one-segment detonator;

[0098] S32b, the charge in each hole of the positive wedge cut hole group of the first group of cut holes and the second group of cut holes is initiated by using a two-segment detonator after a first predetermined delay time;

[0099] S33b, the second segment of charge in each hole of the center hole group and the anti-wedge cut hole group of the first group of cut holes and the second group of cut holes is initiated by using a three-segment detonator after a second predetermined delay time;

[0100] S34b, the charge in each hole of the auxiliary cut hole group of the first group of cut holes and the second group of cut holes is initiated by using a four-segment detonator after a third predetermined delay time, for trimming the cut cavity formed after the blasting of the foregoing steps to form a regular cut cavity.

[0101] In the present embodiment, the first segment of charge in the anti-wedge cut hole has a length of L / 3 and the second segment of charge has a length of L / 3+d, d being the overlength of the cut hole, and the first segment of charge is blocked by stemming from the second segment of charge; the charge in the positive wedge cut hole has a length of L / 2+d, and the rest is filled with stemming.

[0102] The center hole group is longitudinally arranged with three center holes, from top to bottom being a first center hole, a second center hole and a third center hole; the positive wedge cut hole group is longitudinally arranged with four positive wedge cut holes, from top to bottom being a first positive wedge cut hole, a second positive wedge cut hole, a third positive wedge cut hole and a fourth positive wedge cut hole; the anti-wedge cut hole group is longitudinally arranged with three anti-wedge cut holes, from top to bottom being a first anti-wedge cut hole, a second anti-wedge cut hole and a third anti-wedge cut hole;

[0103] The first section of the first central hole adopts a shaped charge, and the energy gathering direction of the shaped charge is towards the second central hole, the first group of cut holes and the first reverse wedge-shaped cut hole of the second group of cut holes;

[0104] The first section of the second central hole adopts a shaped charge, and the energy gathering direction of the shaped charge is towards the first central hole, the third central hole, the first group of cut holes and the second reverse wedge-shaped cut hole of the second group of cut holes;

[0105] The first section of the third central hole adopts a shaped charge, and the energy gathering direction of the shaped charge is towards the second central hole, the first group of cut holes and the third reverse wedge-shaped cut hole of the second group of cut holes;

[0106] The upper part of the auxiliary cut hole is provided with 1-2 shaped charges, and the energy gathering direction is towards the inside of the cut hole.

[0107] The second section of the charge, the wedge-shaped cut hole and the other charges in the auxiliary cut hole are ordinary charges.

[0108] In the embodiment, the comprehensive use of ordinary charges and shaped charges is beneficial to the control of the blasting effect, and further, through the design of the reverse wedge-shaped cut hole, after the initial detonation, a shape with a narrow upper part and a wide lower part is formed, and the shaped charges are reasonably arranged, which is more beneficial to the control of the throwing direction of the flying stones and achieves the expected blasting purpose.

[0109] In still other embodiments of the present application, based on the same technical concept as the foregoing embodiments, the difference lies in that, as shown in Figure 14 and Figure 15 In step S20, the charging of the blast holes in the central hole group, the first group of cut holes and the second group of cut holes respectively includes the following steps:

[0110] S21c, at least two uncoupled charges are loaded into the holes of the reverse wedge-shaped cut hole group by using the axial segmented charging method, at least one section of charge is loaded into the holes of the wedge-shaped cut hole group, the straight cut hole group and the auxiliary cut hole group, and the holes of the central hole group are reserved as empty holes; the length of the charge loaded in the holes of the straight cut hole group is 3L / 16, and the length of the second section of charge of the reverse wedge-shaped cut hole is 3L / 8;

[0111] In step S30, the detonation of the central hole group, the first group of cut holes and the second group of cut holes includes:

[0112] S31c, one section of detonator is used to detonate the charge in each hole of the straight cut hole group;

[0113] S32c, two sections of detonator are used to detonate the first section of charge in each hole of the reverse wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a first predetermined delay time;

[0114] S33c, using 3-section detonators, after a second predetermined delay time, initiating the charge in each hole of the positive wedge-shaped group of cut holes of the first group of cut holes and the second group of cut holes;

[0115] S34c, using 4-section detonators, after a third predetermined delay time, initiating the second section charge in each hole of the negative wedge-shaped group of cut holes of the first group of cut holes and the second group of cut holes; wherein the position of the first section charge in the hole is closer to the hole mouth relative to the second section charge;

[0116] S35c, using 5-section detonators, after a fourth predetermined delay time, initiating the charge in each hole of the auxiliary group of cut holes of the first group of cut holes and the second group of cut holes, for trimming the cut cavity formed after the blasting of the foregoing steps to form a regular cut cavity.

[0117] Wherein, similar to the foregoing embodiments, the use of shaped charges in some holes improves the energy utilization rate of the cut zone explosives, and the breaking effect of the rock mass in the rock roadway cut zone can be improved.

[0118] The cut blasting method of the present application, through the above initiation steps, forms a larger cut cavity in sequence, and comprehensively uses various charges to improve the energy utilization rate of the cut zone explosives and improve the breaking effect of the rock mass in the rock roadway cut zone, so as to overcome the clamping effect of the surrounding rock on the blasted rock mass during cut blasting, and realize high utilization of the cut hole.

[0119] As can be seen from the foregoing description, the positive-negative wedge-shaped cut blasting excavation construction method provided by the embodiments of the present application uses negative wedge-shaped cut holes and positive wedge-shaped cut holes to cooperate with each other, large and small cut holes, deep and shallow cut holes, to break the rock for cut, which is beneficial to reduce the clamping effect of the surrounding rock of the rock roadway on the cut blasting, improve the utilization of the cut hole, and thus improve the blasting excavation efficiency.

[0120] It should be noted that the various embodiments of the present application have different focuses, but are related to each other and can be referred to each other. In addition, in this document, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0121] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A construction method of a forward-reverse wedge-shaped cutting blasting excavation, characterized in that, The method comprises the steps of: S10, arranging a first group of cut holes, a second group of cut holes and a central hole group below the intersection of the arch line and the center line of the roadway; the first group of cut holes and the second group of cut holes are arranged on both sides of the central hole group, and the first group of cut holes and the second group of cut holes respectively comprise a positive wedge-shaped cut hole group, a negative wedge-shaped cut hole group and an auxiliary cut hole group, the negative wedge-shaped cut hole group and the auxiliary cut hole group are arranged on both sides of the positive wedge-shaped cut hole group, and the negative wedge-shaped cut hole group is arranged adjacent to the central hole group, each central hole of the central hole group is arranged vertically to the working face, the positive wedge-shaped cut hole group comprises a plurality of positive wedge-shaped cut holes, the negative wedge-shaped cut hole group comprises a plurality of negative wedge-shaped cut holes, the positive wedge-shaped cut holes and the negative wedge-shaped cut holes are respectively obliquely intersected with the working face, and the positive wedge-shaped cut holes and the negative wedge-shaped cut holes are arranged laterally staggered; S20, after the arrangement of the central hole group, the first group of cut holes and the second group of cut holes is completed, charging the blast holes of the central hole group, the first group of cut holes and the second group of cut holes respectively; wherein the length of the charge is less than the depth of the blast hole; S30, after the charging is completed, initiating the central hole group, the first group of cut holes and the second group of cut holes.

2. The method of claim 1, wherein, The positive wedge-shaped cut hole group comprises 3n positive wedge-shaped cut holes, the negative wedge-shaped cut hole group comprises 2n negative wedge-shaped cut holes, the auxiliary cut hole group comprises 2n straight cut holes, n is a positive integer, the center line of the positive wedge-shaped cut hole is obliquely intersected with the working face to form at least a first included angle, the negative wedge-shaped cut hole is obliquely intersected with the working face to form at least a second included angle, the openings of the first included angle and the second included angle are on the same side, and the first included angle and the second included angle are complementary.

3. The method of claim 1, wherein, In step S20, the charging of the blast holes of the central hole group, the first group of cut holes and the second group of cut holes respectively comprises the steps of: S21a, using an axial segmented charging method to charge at least two uncoupled charges in the holes of the central hole group, the positive wedge-shaped cut hole group and the negative wedge-shaped cut hole group, and charging at least one charge column into the holes of the auxiliary cut hole group; In step S30, the initiation of the central hole group, the first group of cut holes and the second group of cut holes comprises: S31a, using a 1-segment detonator to initiate the first segment of the charge in each hole of the positive wedge-shaped cut hole group and the negative wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes; S32a, using a 2-segment detonator to initiate the first segment of the charge in each hole of the central hole group after a first predetermined delay time; S33a, using a 3-segment detonator to initiate the second segment of the charge in each hole of the positive wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a second predetermined delay time; S34a, using a 4-segment detonator to initiate the second segment of the charge in each hole of the central hole group and the second segment of the charge in each hole of the negative wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a third predetermined delay time; wherein the position of the first segment of the charge in the hole is closer to the hole mouth than the second segment of the charge. S35a, using 5-section detonator, after the fourth predetermined delay time, detonate the charge in each hole of the auxiliary cut hole group of the first group of cut holes and the second group of cut holes, for trimming the cut cavity formed after the blasting of the foregoing steps, to form a regular cut cavity.

4. The method of claim 3, wherein, The first section charge length in each hole of the positive wedge cut hole group, the negative wedge cut hole group and the central hole group is greater than or equal to L / 4 and less than L / 2; The second section charge length in each hole of the positive wedge cut hole group, the negative wedge cut hole group and the central hole group is greater than or equal to L / 3+0.3m and less than L / 2; The charge in the hole of the auxiliary cut hole group corresponds to the position of the second section charge and is located within the hole cross section; wherein the hole depth of each hole is greater than the cut depth L, and the over-depth of each hole decreases from the center of the cut area to both sides in a gradient, and the inner end of the second section charge and the charge in the hole of the auxiliary cut hole group abuts the hole bottom respectively.

5. The method of claim 1, wherein, In step S20, the charging of the blast holes of the central hole group, the first group of cut holes and the second group of cut holes respectively includes the steps of: S21b, using axial segmented charging method to charge at least two sections of uncoupled charges in the holes of the central hole group and the negative wedge cut hole group, and charging at least one section of charge in the holes of the positive wedge cut hole group and the auxiliary cut hole group; In step S30, the detonation of the central hole group, the first group of cut holes and the second group of cut holes includes: S31b, using 1-section detonator to detonate the first section charge in each hole of the negative wedge cut hole group and the central hole group of the first group of cut holes and the second group of cut holes; S32b, using 2-section detonator to detonate the charge in each hole of the positive wedge cut hole group of the first group of cut holes and the second group of cut holes after a first predetermined delay time; S33b, using 3-section detonator to detonate the second section charge in each hole of the negative wedge cut hole group and the central hole group of the first group of cut holes and the second group of cut holes after a second predetermined delay time; S34b, using 4-section detonator to detonate the charge in each hole of the auxiliary cut hole group of the first group of cut holes and the second group of cut holes after a third predetermined delay time, for trimming the cut cavity formed after the blasting of the foregoing steps, to form a regular cut cavity.

6. The method of claim 5, wherein, The first section charge length of the negative wedge cut hole is L / 3 and the second section charge length is L / 3+d, d is the over-depth length of the cut hole, and the first section charge and the second section charge are blocked by stemming; The charge length in the positive wedge cut hole is L / 2+d, and the rest is filled with stemming.

7. The method of claim 5, wherein, The central hole group is longitudinally arranged with three central holes, from top to bottom, the first central hole, the second central hole and the third central hole, the positive wedge cut hole group is longitudinally arranged with four positive wedge cut holes, from top to bottom, the first positive wedge cut hole, the second positive wedge cut hole, the third positive wedge cut hole and the fourth positive wedge cut hole, and the negative wedge cut hole group is longitudinally arranged with three negative wedge cut holes, from top to bottom, the first negative wedge cut hole, the second negative wedge cut hole and the third negative wedge cut hole; The first section charge of the first central hole uses an energy-gathering charge, and the energy-gathering direction of the energy-gathering charge faces the second central hole, the first negative wedge cut hole of the first group of cut holes and the second group of cut holes; The first section charge of the first central hole uses an energy-gathering charge, and the energy-gathering direction of the energy-gathering charge faces the second central hole, the first negative wedge cut hole of the first group of cut holes and the second group of cut holes; The first section of the second central hole adopts a shaped charge, and the shaped charge cut seam direction is respectively towards the first central hole, the third central hole, the second reverse wedge-shaped cut hole of the first group of cut holes and the second group of cut holes; The first section of the third central hole adopts a shaped charge, and the shaped charge cut seam direction is respectively towards the second central hole, the first group of cut holes and the third reverse wedge-shaped cut hole of the second group of cut holes; The second section of the second central hole, the normal wedge-shaped cut hole and the cut hole in the auxiliary cut hole are common cartridges.

8. The method of claim 1, wherein, The reverse wedge-shaped cut hole is perpendicular to the working face, the first group of cut holes and the second group of cut holes further include a straight cut hole group, the straight cut hole group is arranged between the reverse wedge-shaped cut hole group and the central hole group, the depth of the cut hole of the straight cut hole group is 3L / 8, and L is the depth to be cut; In step S20, the holes in the central hole group, the first group of cut holes and the second group of cut holes are respectively charged, including the following steps: S21c, at least two uncoupled charges are charged into the holes of the reverse wedge-shaped cut hole group by using an axial segmented charging method, at least one section of the cartridge is charged into the holes of the normal wedge-shaped cut hole group, the straight cut hole group and the auxiliary cut hole group, and the holes of the central hole group are reserved as empty holes; the length of the charge in the hole of the straight cut hole group is 3L / 16, and the length of the second charge in the reverse wedge-shaped cut hole is 3L / 8; In step S30, the central hole group, the first group of cut holes and the second group of cut holes are initiated, including: S31c, using 1 section of detonator, initiating the cartridge in each hole of the straight cut hole group; S32c, using 2 sections of detonator, initiating the first section of the cartridge in each hole of the reverse wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a first predetermined delay time; S33c, using 3 sections of detonator, initiating the cartridge in each hole of the normal wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a second predetermined delay time; S34c, using 4 sections of detonator, initiating the second section of the cartridge in each hole of the reverse wedge-shaped cut hole group of the first group of cut holes and the second group of cut holes after a third predetermined delay time; wherein the position of the first section of the cartridge in the hole is closer to the hole than the second section of the cartridge; S35c, using 5 sections of detonator, initiating the cartridge in each hole of the auxiliary cut hole group of the first group of cut holes and the second group of cut holes after a fourth predetermined delay time, for trimming the cut cavity formed after the blasting in the foregoing steps to form a regular cut cavity.

9. The method of claim 1, wherein, The normal wedge-shaped cut hole and the reverse wedge-shaped cut hole are used to form a small cut, three adjacent blast holes constitute a cut hole group, forming an equilateral triangle on the roadway section, and the drilling directions of the three blast holes of the small cut hole group, i.e. the three blast holes of the cut hole group, meet on the same line at the bottom of the small cut hole, and the projection of the line on the tunnel section passes through the centroid of the three triangles.

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