Drilling and blasting construction method for large-section tunnel in urban space
Patent Information
- Application Number
- PCT/CN2026/086657
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-28
- Filing Date
- 2026-03-27
- Publication Date
- 2026-10-01
Smart Images
Figure CN2026086657_01102026_PF_FP_ABST
Abstract
Description
Drill-and-blast construction method for large-section tunnels in urban spaces
[0001] Related applications
[0002] This application claims priority to Chinese patent application No. 202510382459.0, filed on March 28, 2025, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the field of tunnel construction technology, and in particular to a drill-and-blast construction method for large-section tunnels in urban spaces. Background Technology
[0004] In the field of tunnel construction, the drill-and-blast method, as a traditional excavation method, is widely used in various tunnel projects. Traditionally, when designing blasting holes, the required blasting area at the tunnel face is evenly distributed across each blasting hole, thus determining the blasting range of each hole, and the arrangement of each blasting hole is identical.
[0005] However, for large-section tunnels, the working face area is large and often involves various geological conditions. Using the same blasting hole layout scheme in different geological conditions yields significantly different blasting effects. Using the same layout for multiple blasting holes can lead to insufficient precision in controlling the blasting range and effect, easily resulting in uneven blast surfaces, affecting the tunnel's construction quality and aesthetics. Secondly, regarding the release and transmission of blasting energy, existing drill-and-blast methods often involve a single, concentrated blast across the entire working face, causing significant disturbance to the surrounding rock, potentially damaging its stability, increasing construction safety risks, and potentially causing substantial environmental impact. This makes them unsuitable for use in densely populated urban areas. Summary of the Invention
[0006] The main purpose of this application is to propose a drilling and blasting construction method for large-section tunnels in urban spaces, aiming to solve the technical problems in the existing technology of insufficient precision in controlling the blasting range and blasting effect in drilling and blasting construction of large-section tunnels, and the large disturbance of blasting to the surrounding environment.
[0007] To achieve the above objectives, the drilling and blasting construction method for large-section tunnels in urban spaces proposed in this application includes: conducting geological exploration of the tunnel face to obtain geological conditions; dividing the tunnel face into a slotting zone located in the middle of the tunnel face, an auxiliary zone located around the slotting zone, and a peripheral zone located around the auxiliary zone and at the edge of the tunnel face; establishing a blasting model based on the geological conditions; determining the layout scheme of the blasting hole group and the selection scheme of explosives according to the blasting model; wherein, the blasting hole group includes multiple blasting holes located in the slotting zone, the auxiliary zone, and the peripheral zone; using an automatic rock drill to drill multiple blasting holes in the slotting zone, the auxiliary zone, and the peripheral zone according to the layout scheme of the blasting hole group; and sequentially performing micro-delay blasting on the multiple blasting holes in the slotting zone, the auxiliary zone, and the peripheral zone.
[0008] In one embodiment, the step of determining the arrangement scheme of the blasting hole group and the selection scheme of explosives based on the blasting model includes: determining the type of explosives based on the blasting model; determining the maximum charge amount of each blasting hole based on the type of explosives; determining the diameter of the blasting hole based on the maximum charge amount; calculating the first spacing, the second spacing, and the third spacing of the blasting holes based on the hole diameter; wherein the first spacing is the spacing between two adjacent blasting holes in the cut area, the second spacing is the spacing between two adjacent blasting holes in the auxiliary area, and the third spacing is the spacing between two adjacent blasting holes in the peripheral area; and determining the depth of the blasting holes in the cut area, the auxiliary area, and the peripheral area based on the first spacing, the second spacing, and the third spacing, respectively.
[0009] In one embodiment, the step of determining the type of explosive based on the blasting model includes: determining the type of explosive in the blast holes located in the cut-out area and the auxiliary area based on the blasting model; selecting bulk emulsion explosive, non-electric detonator and detonator for the explosive in the blast holes located in the cut-out area and the auxiliary area, and sealing them with plugging material; determining the type of explosive in the blast holes located in the peripheral area based on the blasting model; selecting strip emulsion explosive, non-electric detonator and explosive wire for the explosive in the blast holes located in the peripheral area, and sealing them with plugging material.
[0010] In one embodiment, the bulk emulsion explosive has a loading length of 2m; the detonator weighs 20g or 25g; the detonation wire has a specification of 40g / m; the strip emulsion explosive has a specification of φ32mm and a length of 200mm; and the plug has a length of 0.8m to 1m.
[0011] In one embodiment, the diameter of the blasting hole located in the slotted area is 89 mm to 102 mm, and the diameter of the blasting hole located in the auxiliary area and the peripheral area is ≥50 mm.
[0012] In one embodiment, the first spacing is ≥1m; the second spacing is ≥1m; and the third spacing is ≥0.6m.
[0013] In one embodiment, the step of sequentially performing micro-delay blasting on the plurality of blasting holes in the slotted area, the auxiliary area, and the peripheral area includes: sequentially performing micro-delay blasting on the plurality of blasting holes in the slotted area from the center to the edge of the working face; sequentially performing micro-delay blasting on the plurality of blasting holes in the auxiliary area from the center to the edge of the working face; and sequentially performing micro-delay blasting on the plurality of blasting holes in the peripheral area from the center to the edge of the working face.
[0014] In one embodiment, the step of sequentially detonating multiple blast holes within the cut area from the center to the edge of the working face using differential detonation includes: filling an electric detonator into the blast hole located at the center of the cut area; filling non-electric detonators into the remaining blast holes; connecting the electric detonator and each of the adjacent non-electric detonators with a detonating cord, and connecting each of the non-electric detonators to its adjacent non-electric detonators from the center to the edge of the cut area; and detonating the electric detonator so that the multiple non-electric detonators are detonated sequentially from the center to the edge of the cut area.
[0015] In one embodiment, after the step of sequentially performing micro-delay blasting on multiple blasting holes in the cut area, the auxiliary area, and the peripheral area, the method further includes: using a vibration meter to measure the peak particle vibration velocity and air shock wave overpressure in the tunnel during the blasting process, so as to obtain the peak particle vibration velocity value and the air shock wave overpressure value respectively; and dynamically adjusting the blasting model based on the peak particle vibration velocity value and the air shock wave overpressure value.
[0016] In one embodiment, the step of dynamically adjusting the blasting model based on the peak particle velocity value and the air shock wave overpressure value includes: establishing the blasting model based on the geological conditions; performing blasting simulation based on the blasting model to obtain the predicted peak particle velocity value and the predicted air shock wave overpressure value; comparing the peak particle velocity value and the predicted peak particle velocity value to obtain a peak particle velocity deviation value, and comparing the air shock wave overpressure value and the predicted air shock wave overpressure value to obtain an air shock wave overpressure deviation value; and correcting the blasting model based on the air shock wave overpressure deviation value and the air shock wave overpressure deviation value.
[0017] In one embodiment, before performing micro-delay blasting on the plurality of blasting holes in the cut area, the auxiliary area, and the peripheral area in sequence, the drilling and blasting method further includes:
[0018] Advanced small catheter support is applied to the outer side of the surrounding area.
[0019] In one embodiment, after sequentially performing micro-delay blasting on the plurality of blasting holes in the cut area, the auxiliary area, and the peripheral area, the drilling and blasting construction method further includes:
[0020] Monitor the air quality inside the tunnel;
[0021] Ventilate the tunnel until the air quality inside the tunnel meets the preset requirements.
[0022] The drill-and-blast construction method for large-section tunnels in urban spaces proposed in this application divides the tunnel face, which has a large area, into a cutting zone, an auxiliary zone, and a surrounding zone. A blasting model is established based on the specific geological conditions of the tunnel face, and the blasting process is simulated using this model. This allows for precise setting of the layout of each blasting hole in different zones, enabling more accurate control of the blasting range and effect, resulting in a smoother blasting surface and effectively improving the accuracy of blasting construction. By sequentially performing micro-delay blasting on the blasting holes in the cutting zone, auxiliary zone, and surrounding zone, the energy generated by each blasting hole is released evenly and transmitted orderly from the inside to the outside of the tunnel face. This method enables blasting construction of large-section tunnels with a tunnel face area exceeding 300 square meters, avoiding excessive disturbance to the surrounding rock caused by a single full-area blast. This effectively reduces disturbance to the surrounding environment, ensuring the stability of the surrounding rock and construction safety within urban spaces. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0024] Figure 1 is a structural schematic diagram of an embodiment of the drill-blast construction method for large-section tunnels in urban spaces provided in this application;
[0025] Figure 2 is a schematic diagram of the structure of an embodiment of the explosives in the blasting hole of the slotted area and auxiliary area of the drill-blast construction method for large-section tunnels in urban space provided in this application.
[0026] Figure 3 is a structural schematic diagram of an embodiment of explosives in the blasting hole of the surrounding area of the drilling and blasting construction method for large-section tunnels in urban space provided in this application.
[0027] Figure 4 is a schematic flowchart of an embodiment of the drilling and blasting construction method for large-section tunnels in urban spaces provided in this application;
[0028] Figure 5 is a detailed flowchart of step S40 in Figure 4;
[0029] Figure 6 is a detailed flowchart of step S60 in Figure 4.
[0030] Explanation of icon numbers:
[0031] 10. Working face; 20. Cutting area; 30. Auxiliary area; 40. Peripheral area; 50. Blasting hole; 51. Non-electric detonator; 52. Bulk emulsion explosive; 53. Blocking material; 54. Detonator; 55. Strip emulsion explosive; 56. Explosion line.
[0032] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Embodiments of the present invention
[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0034] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0035] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.
[0036] When existing tunnel drilling and blasting methods are applied to large-section tunnels, the working face area is often large and involves various geological conditions. Using the same blasting hole layout scheme in different geological conditions can result in significantly different blasting effects. Furthermore, using the same layout for multiple blasting holes can lead to insufficient precision in controlling the blasting range and effect, easily resulting in uneven blast surfaces, which negatively impacts the tunnel's construction quality and aesthetics. Secondly, regarding the release and transmission of blasting energy, existing drilling and blasting methods often concentrate the energy released during blasting, causing significant disturbance to the surrounding rock, potentially damaging its stability, increasing construction safety risks, and potentially causing substantial environmental impact.
[0037] This application proposes a drill-and-blast construction method for large-section tunnels in urban spaces, including the following steps:
[0038] S10. Conduct geological exploration at the tunnel face to obtain geological information;
[0039] Please refer to Figure 4, which is a schematic flowchart of an embodiment of the drilling and blasting construction method for large-section tunnels in urban spaces provided in this application. Before blasting, the drilling and blasting construction method for large-section tunnels in urban spaces proposed in this application conducts geological exploration of the geological body within the tunnel blasting range to obtain geological conditions such as the composition of the soil and rock layers, the distribution of groundwater, and the magnitude of ground stress at the tunnel face 10, so as to provide data support for the subsequent blasting model based on the geological conditions.
[0040] S20. Divide the working face into a slotting area located in the middle of the working face, an auxiliary area located outside the slotting area, and a peripheral area located outside the auxiliary area and at the edge of the working face.
[0041] Please refer to Figure 1. Figure 1 is a structural schematic diagram of an embodiment of the drill-blast construction method for large-section tunnels in urban spaces provided in this application. For large-section tunnels, the area of the tunnel face 10 is relatively large, and it is necessary to divide the tunnel face 10 into sections according to its shape. The tunnel face 10 is divided into a cutting area 20, an auxiliary area 30, and a peripheral area 40 from the inside to the outside. The cutting area 20 is located at the center of the tunnel face 10 and can be blasted first to form a free face. The auxiliary area 30 is a certain area outside the cutting area 20. Blasting is carried out after the cutting area 20 is blasted, which plays the role of expanding the cutting effect and assisting in rock breaking. The peripheral area 40 located at the edge of the tunnel face 10 is used to accurately control the blasting profile and improve the blasting accuracy.
[0042] S30. Establish a blasting model based on geological conditions;
[0043] A blasting model based on geological conditions can be established to determine the corresponding blasting equivalent for different geological situations. The blasting simulation process of the model analyzes the propagation path and attenuation law of blasting vibrations in different strata, ensuring similar blasting effects under different geological conditions and resulting in a more uniform blast face. This provides a basis for the subsequent formulation of the layout plan for 50 blasting holes. It should be noted that the blasting model is built using existing computer simulation software.
[0044] S40. Determine the layout scheme of the blasting hole group and the selection scheme of explosives based on the blasting model; wherein, the blasting hole group includes multiple blasting holes located in the cut area, auxiliary area and surrounding area;
[0045] Understandably, the selection schemes for explosives include bulk emulsion explosives 52, strip emulsion explosives 55, detonators 54, non-electric detonators 51, explosive wires 56, plugging materials 53, and other types and combinations thereof. The arrangement schemes for the blasting holes 50 include the arrangement schemes for the blasting holes 50 located in the cut area 20, the arrangement schemes for the blasting holes 50 located in the auxiliary area 30, and the arrangement schemes for the blasting holes 50 located in the peripheral area 40. By analyzing the blasting model to obtain the required blasting yield, the maximum charge amount, hole diameter, hole depth, and other parameters of the blasting holes 50 in different zones can be determined. This allows for precise setting of the blasting effect of each blasting hole 50, thereby more accurately controlling the blasting range and blasting effect, making the blasting surface smoother, and facilitating precise on-site construction.
[0046] S50. Using an automatic rock drill, multiple blasting holes are drilled in the cut area, auxiliary area and surrounding area according to the layout plan of the blasting hole group.
[0047] By inputting the layout scheme of each blasting hole 50 into the automatic rock drilling vehicle, the automatic rock drilling vehicle uses its own high-precision positioning system and multi-degree-of-freedom drill arm to drill multiple blasting holes 50 sequentially on the working face 10 according to preset position coordinates, hole diameter, hole depth and angle and other parameter information. The hole quality is good, the drilling accuracy is high and the degree of mechanization of construction is high.
[0048] S60. Perform micro-delay blasting on multiple blasting holes in the cut area, auxiliary area and surrounding area in sequence.
[0049] Micro-delay blasting sequentially detonates 50 groups of blast holes with millisecond-level time differences. The blast holes 50 located in the cut zone 20 are detonated first, forming a free face, and the fractured rock mass provides an energy release channel for subsequent blasting. After a delay of several milliseconds, the blast holes 50 located in the auxiliary zone 30 are detonated, and with the help of the already formed free face, the rock is made easier to break and thrown outward. After another delay of several milliseconds, the blast holes 50 located in the peripheral zone 40 are detonated, and the rock mass weakened by the first two blasts is used to precisely remove the surrounding rock.
[0050] The drilling and blasting construction method for large-section tunnels in urban spaces proposed in this application divides the tunnel face 10, which has a large area, into a cutting zone 20, an auxiliary zone 30, and a surrounding zone 40. A blasting model is established based on the specific geological conditions of the tunnel face 10, and the blasting process is simulated based on the blasting model. This allows for precise setting of the layout of each blasting hole 50 located in different zones, more accurate control of the blasting range and blasting effect, a smoother blasting surface, and effectively improved blasting construction accuracy. By sequentially performing micro-differential blasting on the blasting holes 50 in the cut area 20, auxiliary area 30, and surrounding area 40, the energy generated by each blasting hole 50 is evenly released and orderly transmitted from the inside to the outside along the tunnel face 10. This enables blasting construction of large-section tunnels with a tunnel face area exceeding 300 square meters, avoiding excessive disturbance to the surrounding rock caused by a single full-area blasting of the tunnel face 10. This effectively reduces disturbance to the surrounding environment, ensuring the stability of the surrounding rock and construction safety within the urban space.
[0051] In one embodiment, step S40 includes:
[0052] S41. Determine the type of explosive based on the blasting model;
[0053] S42. Determine the maximum charge amount for each blast hole based on the type of explosive.
[0054] S43. Determine the diameter of the blasting hole based on the maximum charge amount;
[0055] S44. Calculate the first spacing, second spacing and third spacing of the blasting holes according to the hole diameter; wherein, the first spacing is the spacing between two adjacent blasting holes 50 in the slotted area 20, the second spacing is the spacing between two adjacent blasting holes 50 in the auxiliary area 30, and the third spacing is the spacing between two adjacent blasting holes 50 in the peripheral area 40.
[0056] S45. Determine the depth of the blasting holes in the slotted area, auxiliary area, and peripheral area according to the first spacing, the second spacing, and the third spacing, respectively.
[0057] Please refer to Figure 5, which is a detailed flowchart of step S40 in Figure 4. Based on the blasting model, the blasting yield of each blasting hole 50 is determined according to the geological conditions of its location. The most suitable type and combination of explosives are then determined based on the geological conditions, thereby determining the maximum charge of each blasting hole 50. The hole diameter of the blasting hole 50 is then determined by the minimum value among the maximum charge values of multiple blasting holes 50, ensuring that the blasting hole 50 can accommodate the explosive and that the explosive has sufficient effective space within the blasting hole 50. Subsequently, the first spacing of the blasting holes 50 in the cut area 20, the second spacing of the blasting holes 50 in the auxiliary area 30, and the third spacing of the blasting holes 50 in the peripheral area 40 are determined based on the hole diameter. Finally, the first spacing is used to determine the spacing of the cut area... The blasting range of each blasting hole 50 within the cut zone 20 is determined, thereby determining the depth of each blasting hole 50 within the cut zone 20. This ensures that the depth of the blasting holes 50 within the cut zone 20 matches the first spacing, guaranteeing concentrated energy and sufficient penetration to break deep rock masses. The blasting range of each blasting hole 50 within the auxiliary zone 30 is determined through the second spacing, thereby determining the depth of each blasting hole 50 within the auxiliary zone 30. This ensures that the depth of the blasting holes 50 within the auxiliary zone 30 matches the second spacing, balancing the effects of expanding the cut zone and weakening the rock mass. The blasting range of each blasting hole 50 within the peripheral zone 40 is determined through the third spacing, thereby determining the depth of each blasting hole 50 within the peripheral zone 40. This ensures that the depth of the blasting holes 50 within the peripheral zone 40 matches the third spacing, achieving precise control of the blasting range and resulting in a smoother blasting surface.
[0058] In one embodiment, step S41 includes:
[0059] S411. Determine the types of explosives in the blast holes located in the cut-out area and auxiliary area according to the blasting model; the explosives in the blast holes 50 located in the cut-out area 20 and auxiliary area 30 are selected as bulk emulsion explosives 52, non-electric detonators 51 and detonators 54, and are sealed with plugs 53.
[0060] Please refer to Figure 2. Figure 2 is a structural schematic diagram of an embodiment of the explosives in the blasting hole 50 of the cut area 20 and auxiliary area 30 of the drill-blast construction method for large-section tunnels in urban space provided in this application. The explosives in the blasting hole 50 of the cut area 20 and auxiliary area 30 are selected from bulk emulsion explosives 52, non-electric detonators 51 and detonators 54. The detonator 54 and non-electric detonators 51 are filled at the bottom of the blasting hole 50, the bulk emulsion explosives 52 are filled in a plastic tube, and the opening of the blasting hole 50 is sealed with a plug 53 to prevent gas leakage during the explosion of the bulk emulsion explosives 52.
[0061] S412. Determine the type of explosives in the blasting holes located in the perimeter area based on the blasting model; the explosives in the blasting holes 50 located in the perimeter area 40 are strip-shaped emulsion explosives 55, non-electric detonators 51 and explosive wires 56, and are sealed with plugs 53.
[0062] Please refer to Figure 3. Figure 3 is a structural schematic diagram of an embodiment of the explosives in the blasting hole 50 of the perimeter area 40 of the drilling and blasting construction method for large-section tunnels in urban space provided in this application. The explosives in the blasting hole 50 of the perimeter area 40 are strip-shaped emulsion explosives 55, non-electric detonators 51, and detonation wires 56. There are three strip-shaped emulsion explosives 55. The non-electric detonators 51 and strip-shaped emulsion explosives 55 are filled at the bottom of the blasting hole 50. The blasting hole 50 is led out through the detonation wires 56, and the opening of the blasting hole 50 is sealed by the plug 53 to prevent the gas generated when the strip-shaped emulsion explosives 55 explodes from leaking out.
[0063] In one embodiment, the bulk emulsion explosive 52 has a loading length of 2m; the detonator weighs 20g or 25g; the explosive wire has a specification of 40g / m; the strip emulsion explosive has a specification of φ32mm and a length of 200mm; and the plug 53 has a length of 0.8m to 1m.
[0064] In one embodiment, the diameter of the blasting holes located in the slotting area is 89 mm to 102 mm, and the diameter of the blasting holes located in the auxiliary area and the surrounding area is ≥50 mm.
[0065] It should be noted that in traditional drill-and-blast methods, the arrangement of blasting holes 50 usually follows the principle of "short advance, dense holes, and weak blasting," and the diameter of the blasting holes 50 generally does not exceed 40mm. However, in the drill-and-blast construction method for large-section tunnels in urban spaces proposed in this application, the diameter of each blasting hole 50 located in the cut area 20 is 89mm to 102mm, and the diameter of a single blasting hole 50 located in the auxiliary area 30 and the surrounding area 40 is not less than 50mm. This increases the maximum charge of the blasting holes 50, thereby increasing the blasting range of each blasting hole 50, reducing the number of blasting holes 50, and effectively increasing the blasting depth of a single working face 10, thus significantly improving the efficiency of drill-and-blast construction.
[0066] It should be noted that the maximum charge amount for each blast hole 50 is calculated according to the formula PPV=644(R / W). 1 / 2 ) -1.22 The calculations determined that PPV is 25 mm / s, R is the distance between the location of the blasting hole 50 and the edge of the blasting range, and W is the maximum charge (MIC) of the blasting hole 50. In this construction method, the minimum maximum charge of each blasting hole 50 exceeds 10 kg; therefore, the hole diameter of the blasting hole 50 is designed to be ≥50 mm.
[0067] In one embodiment, the first spacing is ≥1m; the second spacing is ≥1m; and the third spacing is ≥0.6m.
[0068] Furthermore, in traditional drill-and-blast methods, the spacing between blasting holes 50 is typically 0.7m to 0.8m. However, in the drill-and-blast construction method for large-section tunnels in urban spaces proposed in this application, the spacing between blasting holes 50 in the cut area 20 and auxiliary area 30 is not less than 1m, and the spacing between blasting holes 50 in the peripheral area 40 is not less than 0.6m. By increasing the blasting range of a single blasting hole 50, the number of blasting holes 50 is significantly reduced, and the amount of explosives consumed per unit area of the tunnel face 10 is effectively reduced, thus saving explosives and lowering construction costs.
[0069] It should be noted that the drilling depth of each blasting hole 50 is determined based on the spacing of the blasting holes 50 and the maximum charge amount, with the drilling depth L=L s +L c , filling length L s The spacing between blast holes should not be less than 50mm, and the charge length L c =MIC / 1.59, where MIC is the maximum charge of the blast hole 50, so the depth range of each blast hole 50 is 5.5m to 6m.
[0070] In one embodiment, step S60 includes:
[0071] S61. Multiple blasting holes in the cut area are sequentially blasted with micro-differential blasting from the middle to the edge of the working face.
[0072] S62. Multiple blasting holes in the auxiliary area are sequentially blasted with micro-delay blasting from the middle to the edge of the working face;
[0073] S63. Multiple blasting holes in the surrounding area are sequentially blasted with micro-delay blasting from the center to the edge of the working face.
[0074] Please refer to Figure 6, which is a detailed flowchart of step S60 in Figure 4. Multiple blasting holes 50 in the blasting hole group 50 are arranged sequentially from the center to the edge of the working face 10. During micro-delay blasting of the multiple blasting holes 50, micro-delay blasting is performed on the multiple blasting holes 50 in each zone separately. Simultaneously, micro-delay blasting is also performed on the entire cut zone 20, auxiliary zone 30, and peripheral zone 40. After the blasting holes 50 in the cut zone 20 are blasted, the blasting of the blasting holes 50 in the auxiliary zone 30 is carried out. After the blasting holes 50 in the auxiliary zone 30 are blasted, the blasting of the blasting holes 50 in the peripheral zone 40 is carried out. First, micro-delay blasting is performed on the multiple blasting holes 50 in the cut zone 20, with sequential detonation using millisecond-level time differences, allowing for concentrated energy release and fracturing of the core rock mass of the working face 10, forming a free face. Subsequently, multiple blasting holes 50 within the auxiliary zone 30 were subjected to micro-delay blasting. Utilizing the existing free face, the rock was made more easily broken and thrown outwards, expanding the excavation effect and weakening the integrity of the surrounding rock mass. Finally, multiple blasting holes 50 within the peripheral zone 40 were subjected to micro-delay blasting, employing precisely controlled smooth blasting technology to ensure the excavation face flatness met design requirements and reduce over- and under-excavation. This zoned micro-delay blasting method allows blasting energy to be transmitted systematically from the inside to the outside along the tunnel face 10, effectively reducing disturbance to the surrounding environment, ensuring the stability of the surrounding rock and construction safety, while optimizing the blasting effect and improving construction efficiency and quality.
[0075] In one embodiment, step S61 includes:
[0076] S611. Fill the blasting hole located in the center of the slotting area with an electric detonator.
[0077] S612. Fill the remaining blast holes with non-electric detonators;
[0078] S613. Connect the electric detonator and each of the adjacent non-electric detonators with a detonating cord, and connect each non-electric detonator to its adjacent non-electric detonator from the middle to the edge of the slotted area.
[0079] S614. Detonate the electric detonator so that several non-electric detonators are detonated sequentially from the center to the edge of the slotted area.
[0080] Furthermore, by installing an electric detonator in the blast hole 50 at the very center of the cut area 20, the electric detonator serves as the detonation source. Positioning the electric detonator at the very center of the cut area 20 allows the blasting energy to diffuse evenly in all directions, initially fracturing the core rock mass. By installing non-electric detonators 51 in the remaining blast holes 50, the excellent millisecond-level delay performance of the non-electric detonators 51 enables sequential detonation according to a preset time difference, achieving a micro-delay blasting effect in conjunction with the electric detonators. The electric detonators and adjacent non-electric detonators 51 are connected by detonating cords, and each non-electric detonator 51 is sequentially connected from the center to the edge of the cut area 20, forming an orderly detonation network from the inside out. This ensures that the blasting energy is released along the designed path, gradually fracturing the rock mass and reducing energy waste and unnecessary disturbance to the surrounding rock. It can be explained that the blasting holes 50 in the auxiliary zone 30 and the peripheral zone 40 are also filled with non-electric detonators 51, and are connected to the non-electric detonators 51 in the cut zone 20 through the detonating tube along the direction from the middle to the edge of the working face 10. After the electric detonator in the middle of the cut zone 20 is detonated, the remaining non-electric detonators 51 in the entire working face 10 are detonated in sequence, realizing micro-delay blasting from the cut zone 20, the auxiliary zone 30 to the peripheral zone 40.
[0081] In one embodiment, after step S60, the drill-and-blast construction method for large-section tunnels in urban spaces proposed in this application further includes:
[0082] S70. A vibration meter is used to measure the peak vibration velocity of particles and the overpressure of air shock waves in the tunnel during the blasting process, so as to obtain the peak vibration velocity value of particles and the overpressure value of air shock waves respectively.
[0083] S80. The blasting model is dynamically adjusted based on the peak vibration velocity of the particles and the overpressure value of the air shock wave.
[0084] It should be noted that by setting up a vibration meter to capture the changes in the vibration velocity of rock mass particles under the action of blasting in real time at the moment of blasting, the peak vibration velocity value of the particles and the overpressure value of the air shock wave are accurately recorded. Then, the peak vibration velocity value of the particles and the overpressure value of the air shock wave are compared with the blasting model, so as to dynamically adjust the blasting model, continuously optimize the blasting model, and accurately adapt it to the actual construction conditions.
[0085] In one embodiment, step S80 includes:
[0086] S81. Establish a blasting model based on geological conditions;
[0087] S82. Perform blasting simulation based on the blasting model to obtain the predicted peak vibration velocity of the particles and the predicted overpressure of the air shock wave.
[0088] S83. Compare the peak vibration velocity value of the particle with the predicted peak vibration velocity value of the particle to obtain the peak vibration velocity deviation value of the particle, and compare the overpressure value of the air shock wave with the predicted overpressure value of the air shock wave to obtain the overpressure deviation value of the air shock wave.
[0089] S84. The blasting model is corrected based on the overpressure deviation value of the air shock wave and the overpressure deviation value of the air shock wave.
[0090] Furthermore, the initial blasting model is based on geological conditions. This initial model is built solely based on geological conditions obtained from geological exploration, which may differ from actual geological conditions. This leads to deviations between the predicted peak particle velocity and the predicted air shock wave overpressure obtained through blasting simulation and the actual situation. By comparing the peak particle velocity values obtained during actual blasting with the predicted values, and comparing the air shock wave overpressure values with the predicted values, the deviation value of the peak particle velocity and the deviation value of the air shock wave overpressure are obtained. These deviations allow for correction of the blasting model, making it more closely aligned with actual blasting conditions. This provides more scientific guidance for subsequent blasting operations, ensuring the safety, efficiency, and accuracy of construction.
[0091] In one embodiment, prior to step S60, the drill-and-blast construction method for large-section tunnels in urban spaces proposed in this application further includes:
[0092] S59. Apply advanced small-diameter tube support to the outer side of the surrounding area.
[0093] Understandably, before blasting, advanced small guide pipe support is installed on the outer side of the surrounding area 40 to reinforce the rock mass at the edge of the tunnel blasting range, improve the stability of the surrounding rock mass, reduce the disturbance of the surrounding rock mass caused by blasting, effectively control the deformation of the tunnel excavation face, and ensure construction safety.
[0094] In one embodiment, after step S60, the drill-and-blast construction method for large-section tunnels in urban spaces proposed in this application further includes:
[0095] S90, Monitor air quality inside the tunnel;
[0096] S100. Ventilate the tunnel until the air quality inside the tunnel meets the preset requirements.
[0097] It should be noted that after the blasting operation at the tunnel face is completed, a gas detector is used to monitor the air quality inside the tunnel after the blast. Specifically, this includes monitoring the concentrations of gases such as oxygen, methane, hydrogen sulfide, carbon monoxide, and radon. Ventilation is also carried out inside the tunnel to ensure that the air velocity inside the tunnel is not less than 0.5 m / s until the air quality monitoring data shows that the concentration of harmful gases and dust content has decreased to the preset safety standard range, ensuring that construction personnel can safely enter the tunnel to continue subsequent operations.
[0098] The above are merely exemplary embodiments of this application and do not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.
Claims
1. A drill-and-blast construction method for large-section tunnels in urban spaces, wherein, The drilling and blasting construction method includes: Geological exploration was conducted at the tunnel face to obtain geological information; The working face is divided into a slotting area located in the middle of the working face, an auxiliary area located around the slotting area, and a peripheral area located around the auxiliary area and at the edge of the working face. A blasting model was established based on the aforementioned geological conditions; The layout scheme of the blasting hole group and the selection scheme of explosives are determined according to the blasting model; wherein, the blasting hole group includes multiple blasting holes respectively located in the slotting area, the auxiliary area and the surrounding area; Using an automatic rock drill, multiple blasting holes are drilled in the cut area, the auxiliary area, and the surrounding area according to the arrangement scheme of the blasting hole group; Micro-delay blasting is performed sequentially on multiple blasting holes in the slotted area, the auxiliary area, and the surrounding area.
2. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 1, wherein, The steps of determining the arrangement scheme of the blasting hole group and the selection scheme of explosives based on the blasting model include: The type of explosive is determined based on the blasting model; The maximum charge amount for each of the aforementioned blast holes is determined according to the type of explosives. The diameter of the blast hole is determined based on the maximum charge amount; The first spacing, second spacing, and third spacing of the blasting holes are calculated based on the hole diameter; wherein, the first spacing is the spacing between two adjacent blasting holes in the slotted area, the second spacing is the spacing between two adjacent blasting holes in the auxiliary area, and the third spacing is the spacing between two adjacent blasting holes in the peripheral area. The depths of the blast holes in the slotted area, the auxiliary area, and the peripheral area are determined according to the first spacing, the second spacing, and the third spacing, respectively.
3. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 2, wherein, The step of determining the type of explosive based on the blasting model includes: The type of explosives in the blast holes located in the cut-out area and the auxiliary area is determined according to the blasting model; the explosives in the blast holes located in the cut-out area and the auxiliary area are selected as bulk emulsion explosives, non-electric detonators and detonators, and are sealed with plugging material; The type of explosives in the blasting hole located in the peripheral area is determined according to the blasting model; the explosives in the blasting hole located in the peripheral area are selected from strip-shaped emulsion explosives, non-electric detonators and explosive wires, and are sealed with the plugging material.
4. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 3, wherein, The bulk emulsion explosive has a filling length of 2m; the detonator weighs 20g or 25g; the detonation wire has a specification of 40g / m; the strip emulsion explosive has a specification of φ32mm and a length of 200mm; the plug has a length of 0.8m to 1m.
5. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 2, wherein, The diameter of the blasting hole located in the slotted area is 89mm to 102mm, and the diameter of the blasting hole located in the auxiliary area and the peripheral area is ≥50mm.
6. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 2, wherein, The first spacing is ≥1m; the second spacing is ≥1m; and the third spacing is ≥0.6m.
7. The drill-and-blast construction method for large-section tunnels in urban spaces as described in any one of claims 1 to 6, wherein, The step of sequentially performing micro-delay blasting on the plurality of blast holes in the slotted area, the auxiliary area, and the surrounding area includes: Multiple blasting holes within the slotted area are sequentially detonated from the center to the edge of the working face using micro-differential blasting. Multiple blasting holes within the auxiliary zone are sequentially detonated from the center to the edge of the working face using micro-delay blasting. Multiple blast holes within the surrounding area are sequentially detonated from the center to the edge of the working face using micro-delay blasting.
8. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 7, wherein, The step of sequentially detonating multiple blast holes within the slotted area from the center to the edge of the working face using micro-delay blasting includes: An electric detonator is installed in the blast hole located at the center of the cut area; Non-electric detonators are filled into the remaining blast holes; The electric detonator and each of the adjacent non-electric detonators are connected by a detonating cord, and each of the non-electric detonators is connected to its adjacent non-electric detonator from the middle to the edge of the slotted area. The electric detonator is detonated so that a plurality of the non-electric detonators are detonated sequentially from the center to the edge of the slotted area.
9. The drill-and-blast construction method for large-section tunnels in urban spaces as described in any one of claims 1 to 6, wherein, After the step of sequentially performing micro-differential blasting on the plurality of blasting holes in the slotted area, the auxiliary area, and the peripheral area, the method further includes: A vibration meter was used to measure the peak particle vibration velocity and air shock wave overpressure in the tunnel during the blasting process, so as to obtain the peak particle vibration velocity value and air shock wave overpressure value respectively. The blasting model is dynamically adjusted based on the peak vibration velocity of the particles and the overpressure value of the air shock wave.
10. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 9, wherein, The step of dynamically adjusting the blasting model based on the peak particle vibration velocity value and the air shock wave overpressure value includes: The blasting model was established based on the geological conditions described. Based on the blasting model, a blasting simulation is performed to obtain the predicted peak vibration velocity of the mass particles and the predicted overpressure of the air shock wave. The peak vibration velocity value of the particle is compared with the predicted peak vibration velocity value of the particle to obtain the peak vibration velocity deviation value of the particle, and the overpressure value of the air shock wave is compared with the predicted overpressure value of the air shock wave to obtain the overpressure deviation value of the air shock wave; The blasting model is corrected based on the air shock wave overpressure deviation value and the air shock wave overpressure deviation value.
11. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 1, wherein, Before performing micro-differential blasting on the plurality of blasting holes in the cut area, the auxiliary area, and the surrounding area in sequence, the drilling and blasting construction method further includes: Advanced small catheter support is applied to the outer side of the surrounding area.
12. The drill-and-blast construction method for large-section tunnels in urban spaces as described in claim 1, wherein, After sequentially performing micro-delay blasting on multiple blasting holes in the cut area, the auxiliary area, and the surrounding area, the drilling and blasting construction method further includes: Monitor the air quality inside the tunnel; Ventilate the tunnel until the air quality inside the tunnel meets the preset requirements.