Weak surrounding rock tunnel micro-damage fine blasting method
Through micro-difference control of digital detonators and foam material filling in the gun hole, the problems of large blasting vibration and serious damage to surrounding rocks in the construction of weak surrounding rock tunnels are solved, and the effect of reducing surrounding rock damage and improving construction stability is achieved.
Patent Information
- Application Number
- CN202510481041.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-17
- Publication Date
- 2025-08-01
AI Technical Summary
The existing blasting technology is prone to overexcavation, landslide and slack deformation of surrounding rocks in the construction of weak surrounding rock tunnels. Conventional micro-difference blasting leads to significant stress wave superposition effect, and lacks effective vibration reduction measures and surrounding rock-support coordination.
The micro-difference control of digital detonators and the filling of foam material in the gun hole is adopted. By adjusting the delay time difference of digital detonators and filling of polyurethane foam material in the gun hole, the disturbance of blasting vibration on the surrounding rocks around the tunnel is reduced. The continuous wall protection and air-spaced charging structure is adopted to reduce the direct effect of explosives on the surrounding rocks.
It effectively reduces the damage to surrounding rocks by blasting, reduces the superposition of stress waves, and improves the blasting effect and construction stability of weak surrounding rocks.
Smart Images
Figure CN120403376A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of tunnel blasting construction, and particularly relates to a fine blasting method for micro-damage of soft surrounding rock tunnels. Background Technique
[0002] During the construction of soft surrounding rock tunnels, due to the characteristics of low surrounding rock strength and poor self-stability in existing blasting technologies, problems such as overbreak, collapse, and relaxation deformation of the surrounding rock are likely to occur. Specifically, it is manifested as vibration superposition and surrounding rock damage. Conventional millisecond blasting mostly uses fixed delay parameters, resulting in a significant stress wave superposition effect, which exacerbates the vibration damage of the surrounding rock; the charging structure of the perimeter holes is single (such as coupled charging), and the explosive energy is released concentratedly, causing the expansion of surrounding rock fissures and overbreak; the smooth blasting technology lacks dynamic buffer protection for the perimeter hole walls, and the explosion stress wave directly acts on the surrounding rock, triggering phenomena such as the collapse of local broken zones.
[0003] In recent years, refined blasting technology has been gradually applied to soft surrounding rock tunnels through quantitative design and dynamic control. For example, technologies such as digital detonators are used to optimize the initiation timing and interval charging of perimeter holes, but there are still bottlenecks such as single vibration reduction measures and insufficient synergy between the surrounding rock and support. Therefore, there is an urgent need for a comprehensive blasting method that integrates millisecond control and smooth wall protection and vibration reduction filling to balance construction efficiency and surrounding rock stability. Summary of the Invention
[0004] In view of the above problems, the purpose of the present invention is to provide a fine blasting method for micro-damage of soft surrounding rock tunnels. The present invention reduces the blasting vibration effect by adjusting the delay time difference of digital detonators and filling foam materials in the blast holes, reducing the disturbance to the surrounding rock around the tunnel, thereby improving the blasting effect of soft surrounding rock.
[0005] The technical solution of the present invention lies in: a fine blasting method for micro-damage of soft surrounding rock tunnels, including the following steps: S1: Use drilling equipment to drill cut holes, auxiliary holes, outer ring tunneling holes, floor holes, and perimeter holes on the tunnel face respectively; S2: Charge the cut holes and auxiliary holes with a continuous charging structure, charge the outer ring tunneling holes and floor holes with a wall protection continuous charging structure, and charge the perimeter holes with a wall protection air interval charging structure; S3: Initiate the cut holes, auxiliary holes, outer ring tunneling holes, and floor holes with digital detonators, and initiate the perimeter holes with detonating cords + digital detonators. The digital detonator initiation method uses millisecond micro-difference control, and according to the initiation sequence of the cut holes, auxiliary holes, outer ring tunneling holes, perimeter holes, and floor holes, complete the blasting of the soft surrounding rock tunnel.
[0006] In the step S1, the cut holes are located on both sides below the center of the tunnel blasting area, including a first cut hole and a second cut hole. The first cut hole and the second cut hole are distributed vertically, with the first cut hole above the second cut hole. The perimeter holes are located at the edge of the tunnel blasting area, including a second perimeter hole distributed along the upper part of the tunnel contour, a first perimeter hole and arch foot holes distributed on both sides of the upper part of the tunnel contour, and floor holes distributed along the lower part of the tunnel contour. The outer ring tunneling holes are located inside the perimeter holes, including a first outer ring tunneling hole and a second outer ring tunneling hole, and the first outer ring tunneling hole is inside the second outer ring tunneling hole.
[0007] In the step S1, the auxiliary holes are located between the cut holes, the outer ring tunneling holes and the floor holes, including a first auxiliary hole, a second auxiliary hole, a third auxiliary hole, a fourth auxiliary hole, a fifth auxiliary hole, a sixth auxiliary hole, a seventh auxiliary hole, an eighth auxiliary hole, a ninth auxiliary hole and a tenth auxiliary hole. The first auxiliary hole, the second auxiliary hole, the third auxiliary hole, the fourth auxiliary hole, the fifth auxiliary hole and the sixth auxiliary hole are distributed vertically, and the ninth auxiliary hole and the tenth auxiliary hole are distributed horizontally.
[0008] In the step S2, the continuous charge structure for charging includes a PVC pipe filled with explosive inside. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and stemming is provided at the other end.
[0009] In the step S2, the continuous charge structure for the retaining wall includes a PVC pipe filled with foam material on the side close to the reserved surrounding rock. The foam material is polyurethane material. The PVC pipe is filled with explosive on the side close to the excavated rock mass. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and stemming is provided at the other end.
[0010] In the step S2, the air-decked charge structure for the retaining wall includes a PVC pipe filled with foam material on the side close to the reserved surrounding rock. The foam material is polyurethane material. The PVC pipe is filled with explosive at equal intervals on the side close to the excavated rock mass. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and stemming is provided at the other end. The digital electronic detonator is connected with a detonating cord, and the detonating cord passes through the stemming and extends towards the outside of the tunnel.
[0011] In the step S3, digital detonators are used for initiation, and the time difference setting range for each section of digital detonators is 40 ms to 60 ms.
[0012] The technical effects of the present invention are as follows: 1. The present invention adopts a casing charge structure in the outer ring tunneling holes, peripheral holes and floor holes, and foam materials are filled on the side close to the reserved surrounding rock, so that the explosive shock wave and stress wave do not directly act on the surrounding rock, thereby reducing the damage to the surrounding rock; 2. The present invention adopts millisecond delay controlled blasting for the blasting holes, and the blasting at different positions is not synchronous, which can reduce the amount of explosives detonated simultaneously, thereby reducing the superposition effect of the stress wave after blasting and reducing the damage to the surrounding rock.
[0013] The following will be further described in conjunction with the accompanying drawings. Description of the Drawings
[0014] Figure 1 It is a schematic diagram of the interface of a fine blasting with micro-damage for a soft surrounding rock tunnel according to an embodiment of the present invention.
[0015] Figure 2 It is a sectional view of the casing charge structure according to an embodiment of the present invention.
[0016] Figure 3 It is a structural diagram of the continuous casing charge according to an embodiment of the present invention.
[0017] Figure 4 It is a structural diagram of the air-decked casing charge according to an embodiment of the present invention.
[0018] Figure 5 It is a structural diagram of the continuous charge according to an embodiment of the present invention.
[0019] Description of the reference numerals: 1 - First cut hole; 2 - Second cut hole; 3 - First auxiliary hole; 4 - Second auxiliary hole; 5 - Third auxiliary hole; 6 - Fourth auxiliary hole; 7 - Fifth auxiliary hole; 8 - Sixth auxiliary hole; 9 - Seventh auxiliary hole; 10 - Eighth auxiliary hole; 11 - First outer ring tunneling hole; 12 - Second outer ring tunneling hole; 13 - Ninth auxiliary hole; 14 - Tenth auxiliary hole; 15 - First peripheral hole; 16 - Second peripheral hole; 17 - Floor hole; 18 - Arch-foot blast hole. Detailed Embodiment Embodiment 1
[0020] As Figures 1 to 5 shown, a method for fine blasting with micro-damage in a soft surrounding rock tunnel includes the following steps: S1: Use a rock drilling device to drill cut holes, auxiliary holes, outer ring tunneling holes, floor holes and peripheral holes on the tunnel face respectively; S2: Charge the cut holes and auxiliary holes with a continuous charge structure, charge the outer ring tunneling holes and floor holes with a casing continuous charge structure, and charge the peripheral holes with a casing air-decked charge structure; S3: Detonate the cut holes, auxiliary holes, outer ring tunneling holes, and floor holes using digital detonators, and detonate the perimeter holes using detonating cords + digital detonators. The digital detonator detonation method uses millisecond differential control. According to the detonation sequence of the cut holes, auxiliary holes, outer ring tunneling holes, perimeter holes, and floor holes, complete the blasting of the soft surrounding rock tunnel.
[0021] The present invention adjusts the delay time difference of digital detonators and fills the blast holes with foam materials to reduce the blasting vibration effect and reduce the disturbance to the surrounding rock of the tunnel, thereby improving the blasting effect of soft surrounding rock.
[0022] In the step S1, the cut holes are located on both sides below the center of the tunnel blasting area, including a first cut hole 1 and a second cut hole 2. The first cut hole 1 and the second cut hole 2 are distributed vertically, and the first cut hole 1 is located above the second cut hole 2. The perimeter holes are located at the edge of the tunnel blasting area, including a second perimeter hole 16 distributed along the upper part of the tunnel contour, a first perimeter hole 15 and an arch foot blast hole 18 distributed on both sides along the upper part of the tunnel contour, and a floor hole 17 distributed along the lower part of the tunnel contour. The outer ring tunneling holes are located inside the perimeter holes, including a first outer ring tunneling hole 11 and a second outer ring tunneling hole 12. The first outer ring tunneling hole 11 is located inside the second outer ring tunneling hole 12.
[0023] In the step S1, the auxiliary holes are located between the cut holes and the outer ring tunneling holes and the floor holes, including a first auxiliary hole 3, a second auxiliary hole 4, a third auxiliary hole 5, a fourth auxiliary hole 6, a fifth auxiliary hole 7, a sixth auxiliary hole 8, a seventh auxiliary hole 9, an eighth auxiliary hole 10, a ninth auxiliary hole 13, and a tenth auxiliary hole 14. The first auxiliary hole 3, the second auxiliary hole 4, the third auxiliary hole 5, the fourth auxiliary hole 6, the fifth auxiliary hole 7, and the sixth auxiliary hole 8 are distributed vertically, and the ninth auxiliary hole 13 and the tenth auxiliary hole 14 are distributed horizontally.
[0024] In the present invention, the cut holes are located on both sides below the center of the tunnel blasting area and can be detonated preferentially to form a free face, improving the subsequent blasting effect. The auxiliary holes are located between the cut holes and the outer ring tunneling holes and belong to the intermediate transition layer of the blasting area. Their main function is to expand the free face formed by the cut holes and create better conditions for the subsequent perimeter hole blasting. The outer ring holes are located in the second row from the outside of the cut holes and control the minimum resistance line distance while expanding the cavity. The perimeter holes are arranged along the contour line at the outermost side of the blasting area, and their main function is to control the shape of the excavation section. The floor holes are located at the bottom of the blasting area and are used to break the floor rock and form a flat base. In the step S2, the continuous charge structure for charging includes a PVC pipe filled with explosive. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and a plugging is provided at the other end.
[0025] In the step S2, the continuous charge structure for the shaft protection includes a PVC pipe. The side of the PVC pipe close to the reserved surrounding rock is filled with a foam material, which is a polyurethane material. The side of the PVC pipe close to the excavated rock mass is filled with explosives. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and stemming is provided at the other end.
[0026] In the step S2, the air interval charge structure for the shaft protection includes a PVC pipe. The side of the PVC pipe close to the reserved surrounding rock is filled with a foam material, which is a polyurethane material. The side of the PVC pipe close to the excavated rock mass is filled with explosives at equal intervals. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and stemming is provided at the other end. The digital electronic detonator is connected to a detonating cord, and the detonating cord passes through the stemming and extends towards the outside of the tunnel.
[0027] In the present invention, the charge structures for the perimeter holes, floor holes, and outer ring tunneling holes adopt the shaft protection charge structure with smooth shaft protection. Before charging, the PVC pipe is cut according to the length of the blast hole, and then the PVC pipe with the appropriate length is axially cut into two symmetrical arc-shaped parts from the middle. The foam material is filled in the cut PVC pipe, and at the same time, according to the explosive quantity requirements of different blast holes, the cartridge is fixed on the upper part of the foam material filled in the arc-shaped PVC pipe. During the charging process, one side of the PVC pipe is close to the excavation contour line direction, and the cartridge side is towards the center direction of the blasting surface. Since the side close to the reserved surrounding rock is filled with a foam material, the explosive shock wave and stress wave can be prevented from directly acting on the surrounding rock, thereby reducing the damage to the surrounding rock.
[0028] In the step S3, digital detonators are used for initiation, and the time difference setting range for each section of digital detonators is 40 ms to 60 ms.
[0029] When the present invention is actually used, the initiation sequence of the digital electronic detonators is from the inside to the outside according to the detonator time difference. Specifically: S1: The first cut hole 1 and the second cut hole 2 are initiated first; S2: Then the first auxiliary hole 3, the second auxiliary hole 4, the third auxiliary hole 5, the fourth auxiliary hole 6, the fifth auxiliary hole 7, the sixth auxiliary hole 8, the seventh auxiliary hole 9, and the eighth auxiliary hole 10 are initiated in sequence; S3: Then the first outer ring tunneling hole 11 and the second outer ring tunneling hole 12 are initiated; S4: Then the ninth auxiliary hole 13 and the tenth auxiliary hole 14 are initiated; S5: Then the first perimeter hole 15 and the second perimeter hole 16 are initiated; S6: Then the floor hole 17 is initiated; S7: Finally, the arch-foot blast hole 18 is initiated to complete the entire blasting process.
[0030] The present invention adopts millisecond-delay controlled blasting for blasting holes. The blasting at different positions is asynchronous, which can reduce the amount of explosive detonated simultaneously, thereby reducing the superposition effect of stress waves after blasting and reducing the damage to the surrounding rock mass.
[0031] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the technical field within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.
Claims
1. A fine blasting method for micro-damage in a tunnel with soft surrounding rock, characterized in that: It includes the following steps: S1: Use a rock drilling device to drill cut holes, auxiliary holes, outer ring tunneling holes, floor holes, and perimeter holes on the tunnel face respectively; S2: Charge the cut holes and auxiliary holes with a continuous charge structure, charge the outer ring tunneling holes and floor holes with a retaining wall continuous charge structure, and charge the perimeter holes with a retaining wall air interval charge structure; S3: Initiate the cut holes, auxiliary holes, outer ring tunneling holes, and floor holes with digital detonators, and initiate the perimeter holes with detonating cords + digital detonators. The digital detonator initiation method uses millisecond differential control. According to the initiation sequence of the cut holes, auxiliary holes, outer ring tunneling holes, perimeter holes, and floor holes, complete the blasting of the soft surrounding rock tunnel.
2. The fine blasting method for micro-damage of soft surrounding rock tunnels according to claim 1, characterized in that: In the step S1, the cut holes are located on both sides below the center of the tunnel blasting area, including a first cut hole (1) and a second cut hole (2). The first cut hole (1) and the second cut hole (2) are distributed vertically. The first cut hole (1) is located above the second cut hole (2). The perimeter holes are located at the edge of the tunnel blasting area, including a second perimeter hole (16) distributed along the upper part of the tunnel contour, a first perimeter hole (15) and an arch foot hole (18) distributed on both sides along the upper part of the tunnel contour, and a floor hole (17) distributed along the lower part of the tunnel contour. The outer ring tunneling holes are located inside the perimeter holes, including a first outer ring tunneling hole (11) and a second outer ring tunneling hole (12). The first outer ring tunneling hole (11) is located inside the second outer ring tunneling hole (12).
3. The fine blasting method for micro-damage of soft surrounding rock tunnels according to claim 2, characterized in that: In the step S1, the auxiliary holes are located between the cut holes and the outer ring tunneling holes and floor holes, including a first auxiliary hole (3), a second auxiliary hole (4), a third auxiliary hole (5), a fourth auxiliary hole (6), a fifth auxiliary hole (7), a sixth auxiliary hole (8), a seventh auxiliary hole (9), an eighth auxiliary hole (10), a ninth auxiliary hole (13), and a tenth auxiliary hole (14). The first auxiliary hole (3), the second auxiliary hole (4), the third auxiliary hole (5), the fourth auxiliary hole (6), the fifth auxiliary hole (7), and the sixth auxiliary hole (8) are distributed vertically. The ninth auxiliary hole (13) and the tenth auxiliary hole (14) are distributed horizontally.
4. The fine blasting method for micro-damage of a soft surrounding rock tunnel according to claim 1, characterized in that: The continuous charge structure in the step S2 includes a PVC pipe filled with explosive inside. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and a plug is provided at the other end.
5. The fine blasting method for micro-damage of a soft surrounding rock tunnel according to claim 1, wherein: The retaining wall continuous charge structure in the step S2 includes a PVC pipe filled with foam material on the side close to the retained surrounding rock. The foam material is polyurethane material. The PVC pipe is filled with explosive on the side close to the excavated rock mass. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and a plug is provided at the other end.
6. The fine blasting method for micro-damage of a soft surrounding rock tunnel according to claim 1, characterized in that: In the retaining wall air interval charging structure in step S2, it includes a PVC pipe. The PVC pipe is filled with foam material on the side close to the reserved surrounding rock. The foam material is polyurethane material. The PVC pipe is filled with explosives at equal intervals on the side close to the excavated rock mass. A digital electronic detonator is provided at one end of the PVC pipe close to the excavated rock mass, and a plugging is provided at the other end. The digital electronic detonator is connected with a detonating cord, and the detonating cord passes through the plugging and extends towards the outside of the tunnel.
7. The fine blasting method for micro-damage of soft surrounding rock tunnel according to claim 1, characterized in that: In step S3, the digital detonator detonates, and the time difference setting range for each section of the digital detonator is 40 ms to 60 ms.