Tunnel face blasting structure adopting mechanical charging and blasting method

Abstract

The invention belongs to the technical field of tunnel construction, and particularly relates to a tunnel face blasting structure adopting mechanical charging and a blasting method. A tunnel face blasting structure adopting mechanical charging comprises a first explosive blasting area located on the edge of the excavation contour of a tunnel face, a fifth explosive blasting area located at the bottom of the tunnel face and a fourth explosive blasting area located in the center of the tunnel face. A second explosive blasting area and a third explosive blasting area are sequentially arranged between the first explosive blasting area and the fourth explosive blasting area. Different explosive densities are adopted in different areas of the tunnel blast hole, so that high smooth blasting quality, labor saving, cost saving, high blasting safety and good stability of surrounding rock after blasting can be realized, and the problems of serious overbreak of the surrounding rock tunnel, low peripheral smooth blasting effect and reduced stability of the surrounding rock are effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a tunnel face blasting structure and a blasting method using mechanized charging. Background Art

[0002] At present, the construction of mountain tunnels at home and abroad is still mainly based on the traditional drilling and blasting method, and the tunnel charging still adopts the method of manually installing finished explosive rolls for blasting. At present, the tunnels in China generally use the method of manual + workbench on site. For example, the excavation section of a single-track railway tunnel is about 70m 2 About 170 blastholes are designed, and 13 people are needed to load the charges, which takes about 2 hours. Not only is the working environment poor, but also the excavation steps are difficult to be close to the rock surface, which makes manual installation of charge coils dangerous, with high safety risks and long working time. Therefore, it is necessary to study and promote mechanized charging technology to solve the problems of high labor intensity, large number of operators and high safety risks caused by the current manual + bench charging of charge coils.

[0003] In order to control tunnel over-excavation, existing tunnels mostly use smooth blasting technology. The technical point of smooth blasting is that the peripheral holes must adopt an uncoupled charging structure. Small-diameter cords and interval charging technology are often used to achieve smooth blasting of peripheral holes. The promotion of peripheral energy-focused smooth blasting technology developed in recent years can reduce the number of peripheral holes and improve the light blasting effect through the energy-focusing effect. Since the diameters of the finished cords are currently universal models with large diameters, it is often necessary to process the finished cords in advance and then load them into the energy-focusing tubes, which not only increases the pre-process but also poses safety issues. As for the mechanized charging technologies currently known at home and abroad, charging trolleys are mostly used for charging operations. However, since the amount of charges in the peripheral holes is generally small, and in order to obtain a good light explosion effect, an uncoupled charging structure is required. Therefore, the charging length and uncoupled charging are mostly controlled by controlling the injection speed. However, it is also difficult to accurately control the charging length and charging uniformity during the injection process. However, considering that there may be local debris or collapsed holes in the blastholes, such a charging structure has poor detonation reliability, which can easily result in failure to reach the critical diameter, resulting in exceeding the sympathetic detonation distance and blind shots.

[0004] Therefore, in order to improve the effect of smooth blasting and to solve the problem of smooth surface blasting control in tunnels using bulk explosives or mixed explosives, the present invention proposes a tunnel face blasting structure and blasting method using mechanized charging in combination with the shaped tube blasting technology, which provides a method for smooth surface blasting control of peripheral holes in tunnels using mechanized charging. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a tunnel face blasting structure and a blasting method using mechanized charging, so as to solve the technical problem of difficult control of smooth surface blasting of peripheral holes in the mechanized charging method, overcome the disadvantage that it is difficult to achieve uneven charging of peripheral holes in the mechanized charging method, and realize full coverage charging of the face through the charging trolley. At the same time, targeted setting of explosive density is realized according to the function of the blast hole. High-density explosives are used for slot holes, slot expansion holes, blast hole lifting holes and bottom plate holes, medium-density explosives are used for auxiliary holes and pressure blast holes, lower-density explosives are used for inner circle holes, and low-density explosives are used for peripheral holes. Digital detonators are used to achieve precise blasting design. By adopting a focusing tube structure, the focusing blasting effect is achieved, which not only reduces the number of peripheral holes, but also reduces surrounding rock damage, improves the light blasting effect, and reduces tunnel over-excavation.

[0006] The technical solution of the present invention is: a tunnel face blasting structure using mechanized charging, comprising a first explosive blasting zone located at the edge of the tunnel face excavation contour, a fifth explosive blasting zone located at the bottom of the tunnel face, and a fourth explosive blasting zone located at the center of the tunnel face, a second explosive blasting zone and a third explosive blasting zone are sequentially arranged between the first explosive blasting zone and the fourth explosive blasting zone, a plurality of peripheral holes are uniformly distributed in the first explosive blasting zone, a plurality of inner circle holes are uniformly distributed in the second explosive blasting zone, and the The third explosive blasting zone is provided with a plurality of pressure holes at a position above the fourth explosive blasting zone, the third explosive blasting zone is provided with a plurality of auxiliary holes at a position on both sides of the fourth explosive blasting zone, the fourth explosive blasting zone is rectangular, and the fourth explosive blasting zone is provided with a plurality of vertically arranged groove holes and expansion holes on both sides of the vertical symmetry axis of the rectangle, a plurality of lifting holes are provided on one side of the fifth explosive blasting zone close to the fourth explosive blasting zone, and a plurality of bottom plate holes are provided at the bottom of the fifth explosive blasting zone.

[0007] The fourth explosive blasting zone and the fifth explosive blasting zone use high-density emulsion explosives, and the density of the high-density emulsion explosives can be taken as 1.1~1.25kg / L; the third explosive blasting zone uses medium-density emulsion explosives, and the density of the medium-density emulsion explosives can be taken as 0.9~1.1kg / L; the second explosive blasting zone uses lower-density emulsion explosives, and the density of the lower-density emulsion explosives can be taken as 0.8~1.0kg / L; the first explosive blasting zone uses low-density explosives, and the density of the low-density explosives can be taken as 0.7~0.9kg / L.

[0008] The peripheral hole adopts a longitudinally continuous radially uncoupled charging structure, including an explosive located at the bottom of the peripheral hole and an energy-gathering tube tightly attached to the explosive, the energy-gathering tube is filled with emulsion explosive, the explosive is provided with a digital detonator, the digital detonator is connected to a detonating cord, and the detonating cord extends out of the hole opening of the peripheral hole.

[0009] The emulsion explosive is bulk non-detonator sensitive explosive.

[0010] The peripheral holes are drilled by a rock drilling rig, with a diameter range of 48 to 50 mm. A continuous charging and uncoupled charging structure of energy-gathering tubes is used in the peripheral holes, and the diameters of the energy-gathering tubes are 25 mm, 28 mm, 30 mm, and 35 mm.

[0011] The inner ring holes, blast holes, auxiliary holes, slot holes, slot expansion holes, blast lifting holes and bottom plate holes adopt a longitudinal continuous charging structure filled with emulsion explosives, wherein the slot holes adopt a radially coupled charging structure.

[0012] A tunnel peripheral hole focused blasting method based on mechanized charging technology, using any of the above-mentioned tunnel face blasting structures using mechanized charging, comprises the following steps: S1: According to the blasting design, a drilling rig is used to drill holes in the first explosive blasting area, the second explosive blasting area, the third explosive blasting area, the fourth explosive blasting area and the fifth explosive blasting area; S2: After the drilling is completed, the mechanical charging system is put into place on the tunnel face. The mechanical charging system can adopt a dedicated mechanized charging trolley or a charging trolley + drilling trolley. The mechanical charging system is provided with an operating platform and a plurality of injection pipes installed on the operating platform near the tunnel face; S3: Use special transport vehicles to transport digital detonators and detonating cords, priming charges and emulsion explosives to the site, and at the same time transport the energy tubes to the tunnel face; S4: A dedicated transport vehicle injects bulk emulsion explosives into the charging system and simultaneously sets the time delay of the digital detonator; S5: Connect and fix the detonating cord and the explosive charge to the end of the energy-gathering tube, and then install them into the surrounding holes. Simultaneously, fix the explosive charge and the digital detonator and place them at the mouths of other gun holes; S6: Use the injection tube to push the energy-gathering tube of the peripheral hole to the bottom of the hole, then inject bulk emulsion explosive into the energy-gathering tube, and simultaneously connect the detonating cord of the peripheral hole; S7: Use the injection tube to push the explosives and digital detonators of other blastholes to the bottom of the holes respectively, and then inject bulk emulsion explosives into the blastholes; S8: Check the detonation network, then exit the charging trolley and carry out blasting operations.

[0013] The technical effects of the present invention are as follows: 1. The present invention adopts a blasting structure of a focusing tube + bulk emulsion explosives in peripheral holes, thereby solving the problem that the peripheral holes of the mechanized charging technology cannot achieve uneven interval charging, and adopts a charging scheme of a focusing tube in the peripheral holes to achieve a good light blasting effect; 2. The present invention adopts different explosive densities in different areas of the tunnel blasting holes, which can achieve high light blasting quality, save labor, save costs, have high blasting safety, and have good surrounding rock stability after blasting, effectively solving the problems of serious over-excavation of surrounding rock tunnels, low peripheral light blasting effect, and reduced surrounding rock stability; 3. The present invention uses a charging trolley for charging operations, and uses high-precision detonators for detonation, which can reduce the number of charging workers from 13 to 4-6, reducing the risks of traditional manual charging operations.

[0014] The following is a further description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a schematic diagram of the functional zoning of mixed explosive blasting in a tunnel face blasting structure using mechanized charging in an embodiment of the present invention.

[0016] Figure 2 It is a schematic diagram of longitudinal charging of peripheral holes in an embodiment of the present invention.

[0017] Figure 3 It is a schematic diagram of a peripheral hole shaped charge according to an embodiment of the present invention.

[0018] Figure 4 This is a design drawing for blasting a finished product cartridge according to an embodiment of the present invention using the prior art.

[0019] Figure 5 This is a blasting design diagram using a shaped energy tube + emulsion explosive according to an embodiment of the present invention.

[0020] Figure numbers: 1-first explosive blasting area, 2-second explosive blasting area, 3-third explosive blasting area, 4-fourth explosive blasting area, 5-fifth explosive blasting area, 6-peripheral holes, 7-inner circle holes, 8-pressure blasting holes, 9-auxiliary holes, 10-expanded slot holes, 11-grooved holes, 12-bottom plate holes, 13-lifting blasting holes, 61-energy-gathering tubes, 62-emulsion explosives, 63-priming charges, 64-digital detonators, 65-detonating cords. Implementation

[0021] Example 1 Figure 1As shown, a tunnel face blasting structure using mechanized charging includes a first explosive blasting area 1 located at the edge of the tunnel face excavation contour, a fifth explosive blasting area 5 located at the bottom of the tunnel face, and a fourth explosive blasting area 4 located at the center of the tunnel face, wherein a second explosive blasting area 2 and a third explosive blasting area 3 are sequentially arranged between the first explosive blasting area 1 and the fourth explosive blasting area 4, a plurality of peripheral holes 6 are uniformly distributed in the first explosive blasting area 1, a plurality of inner circle holes 7 are uniformly distributed in the second explosive blasting area 2, and the third explosive blasting area A plurality of pressure holes 8 are evenly distributed at the position above the fourth explosive blasting area 4, a plurality of auxiliary holes 9 are evenly distributed at the position of the third explosive blasting area 3 on both sides of the fourth explosive blasting area 4, the fourth explosive blasting area 4 is rectangular, and a plurality of vertically arranged groove holes 11 and expanded groove holes 10 are respectively arranged on both sides of the vertical symmetry axis of the rectangle, a plurality of lifting holes 13 are arranged in the fifth explosive blasting area 5 near the side of the fourth explosive blasting area 4, and a plurality of bottom plate holes 12 are arranged at the bottom of the fifth explosive blasting area 5.

[0022] During actual use, the present invention divides the tunnel into the first explosive blasting area 1, the second explosive blasting area 2, the third explosive blasting area 3, the fourth explosive blasting area 4 and the fifth explosive blasting area 5 through the tunnel blasting holes, and adopts different explosive densities in different areas, which can achieve high quality of light blasting, save labor, save costs, have high blasting safety, and have good stability of surrounding rocks after blasting, effectively solving the problems of serious over-excavation of surrounding rock tunnels, low peripheral light blasting effect, and reduced stability of surrounding rocks.

[0023] Embodiment 2 Preferably, on the basis of Embodiment 1, in this embodiment, the fourth explosive blasting zone 4 and the fifth explosive blasting zone 5 use high-density emulsion explosive, and the density of the high-density emulsion explosive can be taken as 1.1~1.25kg / L; the third explosive blasting zone 3 uses medium-density emulsion explosive, and the density of the medium-density emulsion explosive can be taken as 0.9~1.1kg / L; the second explosive blasting zone 2 uses lower-density emulsion explosive, and the density of the lower-density emulsion explosive can be taken as 0.8~1.0kg / L; the first explosive blasting zone 1 uses low-density explosive, and the density of the low-density explosive can be taken as 0.7~0.9kg / L.

[0024] During actual use, the fourth explosive blasting zone 4 and the fifth explosive blasting zone 5 use high-density emulsion explosives, and the density of the high-density emulsion explosives can be 1.1-1.25 kg / L; the third explosive blasting zone 3 uses medium-density emulsion explosives, and the density of the medium-density emulsion explosives can be 0.9-1.1 kg / L; the second explosive blasting zone 2 uses relatively low-density emulsion explosives, and the density of the relatively low-density emulsion explosives can be 0.8-1.0 kg / L; the first explosive blasting zone 1 uses low-density explosives, and the density of the low-density explosives can be 0.7-0.9 kg / L. Different explosive densities are used in different areas, which can achieve high quality of light blasting, save labor, save costs, have high blasting safety, and have good stability of surrounding rocks after blasting, effectively solving the problems of serious over-excavation of surrounding rock tunnels, low peripheral light blasting effect, and reduced stability of surrounding rocks.

[0025] Embodiment 3 Preferably, based on Embodiment 1 or Embodiment 2, in this embodiment, Figure 2 As shown, the charge structure of the peripheral hole 6 includes an explosive 63 located at the bottom of the peripheral hole 6 and a focusing tube 61 closely attached to the explosive 63, wherein the focusing tube 61 contains an emulsion explosive 62, and the explosive 63 is provided with a digital detonator 64, wherein the digital detonator 64 is connected to a detonating cord 65, and the detonating cord 65 extends out of the hole opening of the peripheral hole 6.

[0026] During actual use, the charging structure of the peripheral hole 6 includes an explosive 63 located at the bottom of the peripheral hole 6 and an energy-focusing tube 61 closely attached to the explosive 63. By adopting the energy-focusing tube structure, the energy-focusing blasting effect is achieved, which not only reduces the number of peripheral holes, but also reduces the damage to the surrounding rock, improves the light blasting effect, and reduces tunnel over-excavation.

[0027] Embodiment 4 Preferably, based on Embodiment 1 or Embodiment 3, in this embodiment, Figure 3 As shown, the cross section of the energy-gathering tube 61 is an "8"-shaped double-circle structure.

[0028] In actual use, the cross section of the energy-gathering tube 61 is an "8"-shaped double-circle structure. During blasting, the jet effect of the energy-gathering tube is utilized to gather energy along the center direction of the blasthole, thereby improving the blasting effect.

[0029] Embodiment 5 Preferably, based on Embodiment 1 or Embodiment 4, in this embodiment, the emulsion explosive 62 is bulk capless sensitive explosive.

[0030] In actual use, the emulsion explosive 62 is bulk capless sensitive emulsion explosive, which is safer than finished product explosive rolls. Only by using detonating equipment (detonator or detonating cord) to detonate the detonator first, can the capless sensitive emulsion explosive be detonated.

[0031] Embodiment 6 Preferably, based on Embodiment 1 or Embodiment 5, in this embodiment, the peripheral hole 1 is drilled by a rock drilling rig, and the diameter ranges from 48 to 50 mm. The peripheral hole 1 adopts a continuous charging and uncoupled charging structure of a focusing tube, and the focusing tube 61 has a diameter of 25 mm, 28 mm, and 32 mm.

[0032] During actual use, the energy-focusing tube 61 adopts a small diameter of 25mm, 28mm, 32mm, etc. Compared with the blasthole with a diameter of 48-50mm, since there is a gap between the energy-focusing tube and the running hole, the air interval can be used to achieve the uneven peripheral hole diameter and charging structure, reduce the disturbance to the surrounding rock, and improve the blasting effect.

[0033] Embodiment 7 Preferably, on the basis of Embodiment 1 or Embodiment 6, in this embodiment, the inner circle holes 7, pressure blast holes 8, auxiliary holes 9, groove holes 11, expansion holes 10, blast lifting holes 13 and bottom plate holes 12 adopt a longitudinal continuous charging structure filled with emulsion explosives, wherein the groove holes 11 adopt a radially coupled charging structure.

[0034] During actual use, the inner circle holes 7, pressure blasting holes 8, auxiliary holes 9, slotting holes 11, slot expansion holes 10, blasting lifting holes 13 and bottom plate holes 12 adopt a longitudinal continuous charging structure filled with emulsion explosives, among which the slotting holes 11 adopt a radially coupled charging structure, which can improve the slotting blasting effect.

[0035] Embodiment 8 A tunnel peripheral hole focused blasting method based on mechanized charging technology, using any of the above-mentioned tunnel face blasting structures using mechanized charging, comprises the following steps: S1: According to the blasting design, a drilling rig is used to drill holes in the first explosive blasting area 1, the second explosive blasting area 2, the third explosive blasting area 3, the fourth explosive blasting area 4 and the fifth explosive blasting area 5 respectively; S2: After the drilling is completed, the mechanical charging system is put into place on the tunnel face. The mechanical charging system can adopt a dedicated mechanized charging trolley or a charging trolley + drilling trolley. The mechanical charging system is provided with an operating platform and a plurality of injection pipes installed on the operating platform near the tunnel face; S3: using a special transport vehicle to transport the digital detonator 64 and the detonating cord 65, the detonator 63 and the emulsion explosive 62 to the site, and at the same time transport the energy-gathering tube 61 to the tunnel face; S4: A dedicated transport vehicle injects bulk emulsion explosive 62 into the charging system, and simultaneously sets the delay difference of the digital detonator 64; S5: Connect and fix the detonating cord 65 and the explosive 63 to the end of the energy-gathering tube 61, and then install them into the peripheral hole 6. Simultaneously, fix the explosive 63 and the digital detonator 64 to the other gun holes; S6: Push the energy-gathering tube 61 of the peripheral hole 6 to the bottom of the hole using the injection tube, then inject the bulk emulsion explosive 62 into the energy-gathering tube 61, and simultaneously connect the detonating cord 65 of the peripheral hole 6; S7: using the injection tube to push the detonators 63 and digital detonators 64 of other blastholes to the bottom of the holes respectively, and then injecting the bulk emulsion explosive 62 into the blastholes; S8: Check the detonation network, then exit the charging trolley and carry out blasting operations.

[0036] The following is an example of a newly built single-track railway tunnel. The surrounding rock is mainly hard rock, and the rock type is mainly gneissic granodiorite, grayish white, medium-fine grained structure, and mainly grade III and IV surrounding rock. The overall surrounding rock conditions are good. The tunnel is designed as a trackless transportation single-track railway tunnel. The excavation cross-sectional area of ​​grade III surrounding rock is 72m 2 The drilling operation uses the Epiroc XE3C three-arm drilling rig. The borehole diameter is 50mm, and the tunnel blasthole is charged with BCR emulsion explosive tunnel intelligent charging vehicle. The charging trolley has two telescopic arms, each of which has a charging operation platform. The operation platform is equipped with two injection pipes, which are 10m long and 20mm in diameter, so that the full coverage of the face can be achieved. The bulk emulsion explosive uses low-sensitivity 2# rock emulsion explosive, and the density of the explosive is adjustable between 0.8Kg / L and 1.25Kg / L. The blasting speed is between 3300m / s and 4800m / s. The detonator uses 2# rock emulsion explosive roll, with a model of ø32mm, a single-section charge of 0.3kg, and a length of 30cm. The energy-gathering tubes used in the peripheral holes are of a diameter of ø25mm. The spacing between the holes around the Class III surrounding rock is 65cm, the light explosion layer resistance line is 65cm, and the digital detonator uses Sichuan Weihua's ED-GXP-B8 electronic detonator with a foot line length of 7m. The tunnel III level surrounding rock blasting is done by using a three-arm drilling rig, and the blasting footage is controlled at 3m. To ensure the blasting effect, a pair of slot holes, a pair of expansion holes, two pairs of auxiliary holes, three rows of pressure holes, two rows of lifting holes, one group of inner circle holes, one group of bottom plate holes and one group of peripheral holes are arranged in the middle and lower part of the tunnel.

[0037] Existing technology finished product roll blasting solution: Figure 4As shown, the slotting holes are located in the middle of the tunnel section, with a hole spacing of 40 cm, and 11 holes are arranged in each row; the expansion holes and auxiliary holes are arranged with the slotting holes as the center on the principle of equidistant enlargement, with the expansion holes and the slotting holes spaced 50 cm apart, with a hole spacing of 40 cm, and 12 holes are arranged in each row, with a total of 24 holes; the first pair of auxiliary holes has a hole spacing of 70 cm, with 8 holes arranged in each row, with a total of 16 holes; the second pair of auxiliary holes has a hole spacing of 60 cm, with 9 holes arranged in each row, with a total of 18 holes; the first row of blast holes has a hole spacing of 120 cm, with 2 holes arranged; the second row of blast holes has a hole spacing of 99 cm, with a total of 4 holes arranged; the third row of blast holes has a hole spacing of 109 cm, with a total of 5 holes arranged; the first row of lifting holes has a hole spacing of 100 cm, with a total of 3 holes arranged. The second row of blast holes has a spacing of 94cm, with 8 holes arranged; the inner circle holes of the tunnel are arranged in an arc along the contour of the peripheral holes, with a minimum resistance line spacing of 60cm and a hole spacing of 85cm, with a total of 23 holes arranged; the bottom plate holes are arranged with a spacing of 95cm, with 9 holes arranged; the peripheral holes are arranged according to the tunnel contour, with a spacing of 50cm at the side wall position, with a total of 44 holes arranged. Tunnel blasting uses 2# rock emulsion explosives with a diameter of ø32mm (30cm long, 300g heavy), and the digital detonator uses Sichuan Weihua's ED-GXP-B8 electronic detonator, with a leg line length of 7m and a fixed time interval for sequential detonation. 179 holes were drilled in the III-level surrounding rock, the drilling depth of the peripheral holes was 3.3m, 145 electronic detonators were used, of which the peripheral holes were detonated with detonating cords, a total of 200m of red line detonating cords were used, 5 detonators were used in the peripheral holes, 292kg of finished explosives were used per cycle, the average blasting footage was 3m, and the unit consumption was 1.35kg / m 3 The charging method is manual + bench charging. Workers use gun sticks to insert the powder rolls into the blast holes. There are 13 charging workers in total. According to the cycle process, the drilling time is about 3 hours, the charging time is about 1.5 hours, and the slag discharge time is about 3.5 hours.

[0038] Blasting scheme of the present invention: Figure 5As shown, the slotting holes are located in the middle of the tunnel section, with a hole spacing of 50 cm and 9 holes arranged in each row; the expansion holes and auxiliary holes are arranged with the slotting holes as the center on the principle of equidistant enlargement, with the expansion holes and the slotting holes spaced 50 cm apart and a hole spacing of 60 cm, 8 holes arranged in each row, and 16 holes in total; the first group of auxiliary holes has a hole spacing of 70 cm, 8 holes arranged in each row, and 16 holes in total; the second group of auxiliary holes has a hole spacing of 60 cm, 9 holes arranged in each row, and 18 holes in total; the first row of blast holes has a hole spacing of 120 cm, with 2 holes arranged; the second row of blast holes has a hole spacing of 99 cm, with 4 holes arranged in total; the third row of blast holes has a hole spacing of 109 cm, with 5 holes arranged in total; the first row of lifting holes has a hole spacing of 100 cm, with 3 holes arranged in total. The second row of blast holes has a hole spacing of 94cm, with 8 holes arranged; the inner circle holes of the tunnel are arranged in an arc along the contour of the peripheral holes, with a minimum resistance line spacing of 65cm and a hole spacing of 85cm, with a total of 23 holes arranged; the bottom plate holes have a hole spacing of 95cm, with 9 holes arranged; the peripheral holes are arranged according to the tunnel contour, with a hole spacing of 60cm at the arch position, with 15 holes arranged, and a spacing of 60cm at the side wall position, with a total of 24 holes arranged. 166 holes are arranged in the Class III surrounding rock, 3.3m of peripheral holes are drilled, 140 electronic detonators are used, of which the peripheral holes are detonated with detonating cords, 5 detonators are set, the energy-gathering tube model is ø25mm in diameter, with a total consumption of 125m, 200m of red line detonating cord, 300kg of 2# bulk emulsion explosives are used per cycle, and the detonator uses half a ø32mm finished product roll, with a total consumption of 24kg, 3.2m of blasting footage, and a unit consumption of 1.36kg / m3. According to statistics of the cycle process, the drilling time is about 3 hours. A charging trolley is used on site. There are 2 operators on each of the two working platforms, a total of 4 operators. The charging time is about 2 hours, and the slag discharge time is about 3.5 hours.

[0039] Compared with the blasting scheme of finished product cartridges in the prior art, the blasting scheme of the present invention adopts a charging structure of energy-gathering tubes + bulk emulsion explosives for peripheral holes, and other blastholes adopt a bulk emulsion explosive structure. The tunnel adopts a Hunan Jinshi mixed explosive trolley for charging operations, and high-precision digital detonators are used for detonation, which can reduce the number of charging workers from 13 to 4-6, reducing the risk of traditional manual charging operations and solving the problem that mechanized charging technology cannot achieve uneven intervals and charging in peripheral holes. This method adopts the scheme of energy-gathering tubes and bulk emulsion explosives, which can reduce the number of peripheral holes, improve the quality of light blasting, save labor, save costs, have high blasting safety, and good surrounding rock stability after blasting. The technology of using different density explosives in different blastholes of the present invention can effectively reduce the disturbance of blasting to the surrounding rock, especially the peripheral holes are filled with low-density explosives, which can help reduce the serious problem of over-excavation of surrounding rock tunnels, improve the peripheral light blasting effect, and protect the stability of the surrounding rock.

[0040] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A tunnel face blasting structure using mechanized charging, characterized in that: The invention comprises a first explosive blasting zone (1) located at the edge of the excavation contour of the tunnel face, a fifth explosive blasting zone (5) located at the bottom of the tunnel face, and a fourth explosive blasting zone (4) located at the center of the tunnel face, wherein a second explosive blasting zone (2) and a third explosive blasting zone (3) are arranged in sequence between the first explosive blasting zone (1) and the fourth explosive blasting zone (4), a plurality of peripheral holes (6) are evenly distributed in the first explosive blasting zone (1), a plurality of inner circle holes (7) are evenly distributed in the second explosive blasting zone (2), and the third explosive blasting zone (3) is located between the fourth explosive blasting zone ( 4) is evenly distributed at positions above the fourth explosive blasting zone (4), a plurality of pressure holes (8) are evenly distributed at positions on both sides of the third explosive blasting zone (3) and the fourth explosive blasting zone (4), the fourth explosive blasting zone (4) is rectangular, and the fourth explosive blasting zone (4) is respectively provided with a plurality of vertically arranged slot holes (11) and expansion slot holes (10) along the two sides of the vertical symmetry axis of the rectangle, a plurality of lifting holes (13) are provided in the fifth explosive blasting zone (5) on the side close to the fourth explosive blasting zone (4), and a plurality of bottom plate holes (12) are provided at the bottom of the fifth explosive blasting zone (5).

2. The tunnel face blasting structure using mechanized charging according to claim 1, characterized in that: The fourth explosive blasting zone (4) and the fifth explosive blasting zone (5) use high-density emulsion explosives, and the density of the high-density emulsion explosives can be 1.1-1.25 kg / L; the third explosive blasting zone (3) uses medium-density emulsion explosives, and the density of the medium-density emulsion explosives can be 0.9-1.1 kg / L; the second explosive blasting zone (2) uses relatively low-density emulsion explosives, and the density of the relatively low-density emulsion explosives can be 0.8-1.0 kg / L; the first explosive blasting zone (1) uses low-density explosives, and the density of the low-density explosives can be 0.7-0.9 kg / L.

3. The tunnel face blasting structure using mechanized charging according to claim 1 is characterized in that: The peripheral hole (6) adopts a longitudinally continuous radially uncoupled charge structure, comprising an explosive (63) located at the bottom of the peripheral hole (6) and a focusing tube (61) closely attached to the explosive (63), wherein the focusing tube (61) contains an emulsion explosive (62), and the explosive (63) is provided with a digital detonator (64), wherein the digital detonator (64) is connected to a detonating cord (65), and the detonating cord (65) extends out of the opening of the peripheral hole (6).

4. The tunnel face blasting structure using mechanized charging according to claim 3 is characterized in that: The emulsion explosive (62) is bulk non-detonator sensitive explosive.

5. The tunnel face blasting structure using mechanized charging according to claim 1 is characterized in that: The peripheral holes (1) are drilled using a rock drilling rig and have a diameter range of 48 to 50 mm. A continuous charge-uncoupled charge structure of a focusing tube is used in the peripheral holes (1). The focusing tubes (61) have diameters of 25 mm, 28 mm, 30 mm, and 35 mm.

6. The tunnel face blasting structure using mechanized charging according to claim 1, characterized in that: The inner ring holes (7), the blast holes (8), the auxiliary holes (9), the slot holes (11), the slot expansion holes (10), the blast lifting holes (13) and the bottom plate holes (12) adopt a longitudinal continuous charging structure for loading emulsion explosives, wherein the slot holes (11) adopt a radially coupled charging structure.

7. A tunnel peripheral hole focused blasting method based on mechanized charging technology, using any one of the tunnel face blasting structures using mechanized charging as described in claims 1 to 6, characterized in that: The following steps are involved: S1: According to the blasting design, a drilling rig is used to drill holes in the first explosive blasting area (1), the second explosive blasting area (2), the third explosive blasting area (3), the fourth explosive blasting area (4) and the fifth explosive blasting area (5); S2: After the drilling is completed, the mechanical charging system is put into place on the tunnel face. The mechanical charging system can adopt a dedicated mechanized charging trolley or a charging trolley + drilling trolley. The mechanical charging system is provided with an operating platform and a plurality of injection pipes installed on the operating platform near the tunnel face; S3: using a special transport vehicle to transport the digital detonator (64) and detonating cord (65), the primary explosive (63) and the emulsion explosive (62) to the site, and at the same time transport the shaped energy tube (61) to the tunnel face; S4: A dedicated transport vehicle injects bulk emulsion explosive (62) into the charging system and simultaneously sets the time delay of the digital detonator (64); S5: Connect and fix the detonating cord (65) and the explosive (63) to the end of the energy-gathering tube (61), and then install them into the peripheral hole (6). Simultaneously, fix the explosive (63) and the digital detonator (64) to the mouths of other gun holes; S6: using an injection tube to push the energy-gathering tube (61) of the peripheral hole (6) to the bottom of the hole, and then injecting bulk emulsion explosive (62) into the energy-gathering tube (61), and simultaneously connecting the detonating cord (65) of the peripheral hole (6); S7: using the injection tube, push the detonators (63) and digital detonators (64) of other blast holes to the bottom of the holes respectively, and then inject the bulk emulsion explosive (62) into the blast holes; S8: Check the detonation network, then exit the charging trolley and carry out blasting operations.

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