A method for linear cut slotting of reinforced charge hole

Abstract

This invention provides a method for strengthening the straight-line slotting of charged holes, relating to the field of tunnel construction technology. The method includes: obtaining the rock movement compensation space and determining the diameter, number, and location of the charged slotting holes and the empty holes; preparing a blasting design; drilling holes according to the blasting design, with three to six empty holes and one charged slotting hole located at the geometric center of multiple empty holes; completing the charging filling and the placement of the in-hole detonator and the external connecting detonator in the charged slotting hole according to the blasting design, leaving an air gap at the bottom of the charged slotting hole; adjusting the hole positions in the next cycle of slotting area based on the slotting effect after one blast; when the charged destruction radius is too small, causing the residual hole depth to exceed the preset depth, decreasing the center distance from the charged slotting hole to the empty hole or increasing the charged radius; when the charged destruction radius is too large, causing the residual hole depth to exceed the preset depth, increasing the center distance from the charged slotting hole to the empty hole or decreasing the charged radius.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and more specifically, to a method for straight-line slotting of reinforced explosive charge holes. Background Technology

[0002] Straight-line cut-out with open boreholes originated in Sweden in the 1960s. By creating one or more open boreholes parallel to the tunnel axis, it increases the free face and provides compensation space for rock movement. The diameter of the open boreholes can be the same as the blast holes or larger. Compared to wedge-cut blasting methods, the biggest advantage of straight-line cut-out with open boreholes is that it allows for increased blasting advance without being limited by cross-sectional dimensions. With the widespread use of drilling rigs globally, straight-line cut-out technology has also developed significantly, with blasting advances increasing from 2-3 meters to over 6 meters. However, further increasing the blasting advance can lead to low utilization of open boreholes in the cut-out area due to drilling errors and other factors, resulting in excessive drilling in the cut-out area. Summary of the Invention

[0003] The problem solved by this invention is how to improve the utilization rate of voids and reduce the number of holes drilled in the slotted area.

[0004] To address the above problems, this invention provides a method for reinforcing the straight groove cutting of explosive charge holes, comprising:

[0005] Obtain the rock movement compensation space and determine the diameter, number, and location of the charge slots and empty holes;

[0006] The blasting design is prepared based on the rock movement compensation space, the diameter, number and location of the charge slots and the empty holes;

[0007] Drilling is performed according to the blasting design, the number of the cavities is three to six, the number of the charge slotting hole is one, and the charge slotting hole is located at the geometric center of the plurality of cavities.

[0008] According to the blasting design, the charging and filling of the charging slot hole and the layout of the initiating detonator inside the hole and the connecting detonator outside the hole are completed, and an air gap is provided at the bottom of the charging slot hole.

[0009] After one blast, the hole positions in the next cycle of blasting area are adjusted according to the blasting effect. When the charge destruction radius is too small, causing the residual hole depth to be less than the preset depth, the center distance from the charge blasting hole to the empty hole is reduced or the charge radius is increased. When the charge destruction radius is too large, causing the residual hole depth to be greater than the preset depth, the center distance from the charge blasting hole to the empty hole is increased or the charge radius is decreased.

[0010] Optionally, obtaining the rock movement compensation space includes:

[0011] The required rock movement compensation space for the cut is calculated based on the excavation progress.

[0012] Optionally, the rock movement compensation space required for the cut, calculated based on the excavation progress, satisfies the following formula:

[0013] D e = (3.2 × L) 2 ;

[0014] Among them, D e L represents the rock movement compensation space, in mm; L represents the excavation advance, in m.

[0015] Optionally, the charge slotting holes and the empty holes in the slotting area satisfy the following relationship:

[0016]

[0017] a=k*D e ;

[0018] Where, d e n1 is the diameter of the cavitation hole in mm; n2 is the number of cavitation holes; a is the distance from the center of the charge slot to the cavitation hole in mm; k is the compensation coefficient for rock movement, ranging from 1 to 2.

[0019] Optionally, the center distance between the charge slot and the empty hole satisfies:

[0020]

[0021] Among them, R sh d is the compression radius of an explosive in an infinite medium, expressed in mm. e D represents the diameter of the hole, in mm. c The equivalent charge diameter is in mm.

[0022] Optionally, the excavation advance ranges from 1.5 to 7 meters.

[0023] Optionally, the diameter of the hole ranges from 64 to 140 mm, and the depth ranges from 1.5 to 7 m.

[0024] Optionally, the diameter of the loading slot is in the range of 55 to 76 mm, and the depth is in the range of 1.5 to 7 m.

[0025] Optionally, the center distance between the charge slot and the empty hole is 1 to 2 times the rock movement compensation space, with a smaller value when the rock to be blasted is hard rock and a larger value when the rock to be blasted is soft rock.

[0026] Optionally, the length of the air gap ranges from 10 to 30 cm.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] After obtaining the rock movement compensation space and determining the diameter, number, and location of the charge slotting holes and empty holes, a blasting design can be prepared based on this, and drilling can be carried out. Specifically, three to six empty holes are set as the rock movement compensation space, and a charge slotting hole is set at the geometric center of several empty holes for charging. An air gap is left at the bottom of the charge slotting hole, which improves the utilization rate of empty holes while reducing the damage to the blasting face of the next cycle. The slotting area formed by this invention is relatively large, which can reduce the total number of holes and facilitate rapid construction. Moreover, after one blast, the hole position of the slotting area in the next cycle can be adjusted according to the slotting effect. Specifically, when the charge destruction radius is too small and the residual hole depth is less than the preset depth, the center distance between the charge slotting hole and the empty hole is reduced or the charge radius is increased; when the charge destruction radius is too large and the residual hole depth is greater than the preset depth, the center distance between the charge slotting hole and the empty hole is increased or the charge radius is decreased. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating the method for straight-line slotting of the enhanced charge hole in this invention.

[0030] Figure 2 This is a schematic diagram of the hole arrangement in the slotted area of ​​the present invention. Figure 1 ;

[0031] Figure 3 This is a schematic diagram of the hole arrangement in the slotted area of ​​the present invention. Figure 2 .

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Hole; 2. Discharge slot. Detailed Implementation

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] like Figure 1 As shown, the method for straight-line slotting of reinforced charge holes according to an embodiment of the present invention includes the following steps:

[0036] S100, Obtain the rock movement compensation space and determine the diameter, number and location of the charge slot hole 2 and the empty hole 1;

[0037] S200. Prepare a blasting design based on the rock movement compensation space, the diameter, number and location of the charge slot 2 and the empty hole 1;

[0038] S300. Drill holes according to the blasting design. The number of empty holes 1 is three to six, and the number of charge slotting holes 2 is one. The charge slotting hole 2 is located at the geometric center of multiple empty holes 1.

[0039] S400. According to the blasting design, the charging and filling of the charging slot hole 2 is completed and the initiating detonator inside the hole and the connecting detonator outside the hole are laid out, and an air gap is left at the bottom of the charging slot hole 2.

[0040] S500. After the first blast, adjust the hole positions in the next cycle's slotting area according to the slotting effect. When the charge destruction radius is too small, causing the residual hole depth of Hole 1 to be less than the preset depth, reduce the center distance between the charge slotting hole 2 and Hole 1 or increase the charge radius. When the charge destruction radius is too large, causing the residual hole depth of Hole 1 to be greater than the preset depth, increase the center distance between the charge slotting hole 2 and Hole 1 or decrease the charge radius.

[0041] In this embodiment, the preset depth is 0.3m. The diameter, number, and location of the charging slot holes and empty holes are determined according to the diameter of the drill bit and the type of blasting equipment. The excavation advance ranges from 1.5 to 7m; the diameter of empty hole 1 ranges from 64 to 140mm, and the hole depth ranges from 1.5 to 7m; the diameter of charging slot hole 2 ranges from 55 to 76mm, and the hole depth ranges from 1.5 to 7m; the center-to-center distance between charging slot hole 2 and empty hole 1 is 1 to 2 times the rock movement compensation space, with a smaller value taken when the rock to be blasted is hard rock and a larger value taken when the rock to be blasted is soft rock. In other words, the center-to-center distance between charging slot hole 2 and empty hole 1 is greater in soft rock than in hard rock; the length of the air gap ranges from 10 to 30cm.

[0042] It should be understood that, in this embodiment, the rock movement compensation space can be regarded as the equivalent diameter of the void 1, that is, the diameter of the area enclosed by multiple voids 1; the residual void 1 is the part of the void 1 that is still retained after the blast.

[0043] After obtaining the rock movement compensation space and determining the diameter, number, and location of the charge slotting hole 2 and the empty hole 1, a blasting design can be prepared based on this, and drilling can be carried out. Specifically, three to six empty holes 1 are set as the rock movement compensation space, and a charge slotting hole 2 is set at the geometric center of several empty holes 1 for charging. An air gap is used at the bottom of the charge slotting hole 2. The use of air gap can improve the utilization rate of empty holes 1 while reducing the damage to the blasting face of the next cycle.

[0044] The present invention creates a large slotted area, which can reduce the total number of boreholes and facilitate rapid construction. After one blast, the hole positions in the slotted area of ​​the next cycle can be adjusted according to the slotting effect. Specifically, when the charge destruction radius is too small and the residual hole depth of the empty hole 1 is greater than the preset depth, the center distance between the charge slotting hole 2 and the empty hole 1 is reduced or the charge radius is increased; when the charge destruction radius is too large and the residual hole depth of the empty hole 1 is greater than the preset depth, the center distance between the charge slotting hole 2 and the empty hole 1 is increased or the charge radius is decreased.

[0045] Conventional straight-line slotting methods often reduce the center distance between the slotting hole 2 and the empty hole 1 due to hard surrounding rock, easily leading to perforation. Furthermore, borehole deviation increases the center distance between the slotting hole 2 and the empty hole 1, reducing the utilization rate of the empty hole 1 and affecting the overall blasting effect. In the enhanced straight-line slotting method of this embodiment, not only can the diameters of the slotting hole 2 and the empty hole 1 be flexibly adjusted according to the type of drill bit and blasting equipment available on site, exhibiting good compatibility, but it also has lower drilling requirements. The distances between adjacent empty holes 1 and between the slotting hole 2 and each empty hole 1 are greater, reducing the impact of water pressure and vibration during drilling of adjacent holes on completed holes. Additionally, the larger diameter of the slotting hole 2 facilitates cleaning and reduces the risk of hole collapse and blockage, preventing the slotting hole 2 from being unable to be loaded with explosives.

[0046] The charging slot 2 is far away from other charging holes in the surrounding area, which can effectively avoid desensitization and mis-explosion caused by impact compression of explosives in the back-firing hole.

[0047] In step S100, obtaining the rock movement compensation space includes: calculating the rock movement compensation space required for the excavation based on the excavation progress.

[0048] Specifically, the rock movement compensation space required for the cut is calculated based on the excavation progress according to the following formula:

[0049] D e = (3.2 × L) 2 ;

[0050] Among them, D e L represents the rock movement compensation space, in mm; L represents the excavation advance, in m.

[0051] Optionally, the charge slotting hole 2 and the empty hole 1 in the slotting area satisfy the following relationship:

[0052]

[0053] a=k*D e ;

[0054] Where, d en1 is the diameter of the empty hole 1 in mm; n2 is the number of empty holes 1; a is the center distance from the charging slot hole 2 to the empty hole 1 in mm; k is the compensation coefficient for rock movement, ranging from 1 to 2, with a smaller value for hard rock and a larger value for soft rock, and a smaller value for large advances and a larger value for small advances. In other words, the k value is greater for soft rock than for hard rock, and the k value is greater for small advances than for large advances.

[0055] In step S200, the blasting design includes a charge structure diagram and a borehole coordinate table. During construction, it is necessary to provide drilling and blasting instructions to the drilling rig operator and blasting personnel.

[0056] In step S400, the explosive loading slot 2 can be filled with packaged or bulk explosives of various specifications with a diameter of 25 to 60 mm. The equivalent explosive loading diameter should meet the following relationship:

[0057]

[0058] Among them, D c The equivalent charge diameter is in mm; d c n is the diameter of the explosive charge in mm; n1 is the number of explosives in the bundled explosive charge.

[0059] The compression radius of the borehole charge should satisfy the following relationship:

[0060]

[0061] Among them, R sh ρ is the compression radius of the explosive in an infinite medium, in mm; ρ is the density of the explosive, in kg / m³. 3 D is the detonation velocity of the explosive, in m / s; F is the uniaxial compressive strength of the rock, in Pa.

[0062] After the detonation wave enters the surrounding rock of the borehole, it will form a stress wave in the rock. At the rock-air interface at the empty hole 1, the reflection of the stress wave will cause some of the rock to break and collapse. Therefore, when selecting the calculation coefficient for the center distance between the charge cut hole 2 and the empty hole 1, the rock thickness between the charge cut hole 2 and the empty hole 1 should be slightly greater than the compression radius of the charge to avoid the rock pulverized by the explosive being compacted again, resulting in the failure of the cut. That is, the center distance between the charge cut hole 2 and the empty hole 1 should meet the following requirements:

[0063]

[0064] Among them, R sh d is the compression radius of an explosive in an infinite medium, expressed in mm. e D is the diameter of the hole 1, in mm. c The equivalent charge diameter is in mm.

[0065] The following two examples illustrate the process. During construction, the drilling equipment used was the CRCC Heavy Industry ZYS113 three-arm rock drilling rig, capable of drilling holes from Φ45 to 140 mm in diameter, simultaneously meeting the requirements for blast holes, geological exploration holes, and large-diameter boreholes. The explosives used for blasting were Kemulex aluminum-containing emulsion explosives from Saudi Chemicals, with diameters of 32 mm and 40 mm and a density of 1210 kg / m³. 3 , the explosion velocity is 4900m / s, and the explosion heat is 3800kJ / kg.

[0066] In one embodiment, the surrounding rock of the tunnel is granite, the total length of the tunnel is 1953m, and the uniaxial compressive strength of the rock can reach 180MPa. 64mm and 127mm drill bits are available on site. The diameter of the borehole 1 is 127mm, and the diameter of the loading slot hole 2 is 64mm. When the surrounding rock grade is S1-S3A, the blasting design advance is 5m / cycle. When using a 64mm drill bit to drill the loading slot hole 2, three 32mm explosives bundled together can be used for loading.

[0067] (1) Based on the aforementioned formula, the parameters of the slotted area are calculated as follows: four 127mm holes 1, k value is 1.5, the center distance between the charging slot 2 and the hole 1 is 380mm, the hole depth is 5.2m, and the area of ​​the slotted area is 0.29m². 2 At this point, the arrangement of blast holes in the cut area is shown in the figure. Figure 2 .

[0068] (2) Use AutoCAD to draw the borehole layout diagram and export the coordinates of each hole to create a coordinate table. Import the coordinates into the drilling rig, and drill automatically or manually under the guidance of the rig's positioning system to ensure the accuracy of drilling during large-scale blasting. After drilling is completed, check the position, depth, and inclination of all holes and ensure that the boreholes are unobstructed and free from collapse or blockage.

[0069] (3) After inserting a 20cm empty plastic bottle into the bottom of the loading slot 2 as an air gap, use 3 bundles of 32mm*550mm*0.5kg explosives to form a bundle, and put 7 bundles of explosives into the loading slot 2, with a total explosive charge of 10.5kg. Use plastic bottles filled with a water-sand mixture as packing material to increase the packing density.

[0070] (4) After using the straight-line slotting method for reinforced charge empty holes 24 times, no residual holes of empty hole 1 were observed, that is, the utilization rate of empty hole 1 was 100%. Only 1-2 empty holes 1 remained, and the hole depth was less than 20cm. When the hole bottom error reached 15cm due to drilling deviation, it did not affect the utilization rate of empty hole 1.

[0071] In another embodiment, the surrounding rock of the tunnel is andesite, the total length of the tunnel is 932m, the uniaxial compressive strength of the rock can reach 100MPa, 64mm and 102mm drill bits are available on site, the diameter of the blasting hole 1 is 102mm, the diameter of the charging slot hole 2 is 64mm, when the surrounding rock grade is S1-S3A, the blasting design advance is 5m / cycle.

[0072] (1) Five 102mm empty holes 1 and one 64mm charging hole 2 are set in the slotted area. The value of k is 2. The center distance between the charging hole 2 and the empty hole 1 is 456mm. The hole depth is 5.2m. The area of ​​the slotted area is 0.49m². 2 At this point, the arrangement of blast holes in the cut area is shown in the figure. Figure 3 .

[0073] (2) Use AutoCAD to draw the borehole layout diagram and export the coordinates of each hole to create a coordinate table. Import the coordinates into the drilling rig, and drill automatically or manually under the guidance of the rig's positioning system to ensure the accuracy of drilling during large-scale blasting. After drilling is completed, check the position, depth, and inclination of all holes and ensure that the boreholes are unobstructed and free from collapse or blockage.

[0074] (3) After inserting a 20cm empty plastic bottle into the bottom of the hole as an air gap, use 3 32mm*550mm*0.5kg explosives bundled together to form a bundle of explosives. Insert 7 bundles of explosives into the loading slot 2, with a total explosive charge of 10.5kg. Use plastic bottles filled with a water-sand mixture as packing material to increase the packing density.

[0075] (4) After using the straight-line grooving method for reinforced charge empty holes 10 times, residual holes appeared twice, with a depth of less than 20cm. Even when the bottom error of the hole reached 18cm due to drilling deviation, it did not affect the utilization rate of empty hole 1.

[0076] Readers should understand that in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0077] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for straight-line slotting of reinforced explosive charge holes, characterized in that, include: Obtain the rock movement compensation space and determine the diameter, number, and location of the charge slots and empty holes; The blasting design is prepared based on the rock movement compensation space, the diameter, number and location of the charge slots and the empty holes; Drilling is performed according to the blasting design, with three to six holes and one charge slotting hole, which is located at the geometric center of the plurality of holes. The charge slotting holes and the empty holes in the slotting area satisfy the following relationship: Among them, D e The space for rock movement compensation is in mm; d e n1 is the diameter of the hole, in mm; n2 is the number of holes; a is the distance from the center of the charging slot to the hole, in mm; k is the compensation coefficient for rock movement, ranging from 1 to 2. The distance between the center of the charge slot and the hole is 1 to 2 times the rock movement compensation space, with a smaller value when the rock to be blasted is hard rock and a larger value when the rock to be blasted is soft rock. The center distance between the charge slot and the empty hole satisfies: Among them, R sh d is the compression radius of an explosive in an infinite medium, expressed in mm. e D represents the diameter of the hole, in mm. c The equivalent charge diameter is in mm. According to the blasting design, the charging and filling of the charging slot hole is completed and the initiating detonator inside the hole and the connecting detonator outside the hole are laid out, and an air gap is left at the bottom of the charging slot hole. After one blast, the hole positions in the next cycle of blasting area are adjusted according to the blasting effect. When the charge destruction radius is too small, causing the residual hole depth to be less than the preset depth, the center distance from the charge blasting hole to the empty hole is reduced or the charge radius is increased. When the charge destruction radius is too large, causing the residual hole depth to be greater than the preset depth, the center distance from the charge blasting hole to the empty hole is increased or the charge radius is decreased.

2. The method for straight-line slotting of reinforced charge holes according to claim 1, characterized in that, The acquisition of the rock movement compensation space includes: The required rock movement compensation space for the cut is calculated based on the excavation progress.

3. The method for straight-line slotting of reinforced charge holes according to claim 2, characterized in that, The rock movement compensation space required for the cut, calculated based on the excavation progress, satisfies the following formula: Among them, D e L represents the rock movement compensation space, in mm; L represents the excavation advance, in m.

4. The method for straight-line slotting of reinforced charge holes according to claim 3, characterized in that, The excavation advance ranges from 1.5 to 7 meters.

5. The method for straight-line slotting of reinforced charge holes according to claim 1, characterized in that, The diameter of the hole ranges from 64 to 140 mm, and the depth ranges from 1.5 to 7 m.

6. The method for straight-line slotting of reinforced charge holes according to claim 1, characterized in that, The diameter of the loading slot is in the range of 55 to 76 mm, and the depth is in the range of 1.5 to 7 m.

7. The method for straight-line slotting of reinforced charge holes according to claim 1, characterized in that, The length of the air gap ranges from 10 to 30 cm.

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