Method and system for initiating detonation of electronic detonator by carbon dioxide phase transition induced crack

Abstract

This invention provides a method and system for co-initiating carbon dioxide phase change fracturing and electronic detonators. The method includes: dividing the tunnel face into an explosive blasting zone and a carbon dioxide phase change fracturing zone based on the vertical centerline; drilling conventional blast holes in the explosive blasting zone and fracturing holes and fracturing guide holes in the carbon dioxide phase change fracturing zone; installing electronic detonators in the conventional blast holes and carbon dioxide phase change fracturing devices in the fracturing holes; connecting the electronic detonators in the explosive blasting zone and the excitation heads of the carbon dioxide phase change fracturing devices in the carbon dioxide phase change fracturing zone to an initiation controller via the same bus; detonating the electronic detonators through the initiation controller, sequentially detonating the slotted holes, auxiliary holes, bottom holes, and peripheral holes, and triggering the carbon dioxide phase change fracturing device after the vibration damping interval. This invention greatly improves fracturing efficiency and fracturing device recovery rate, keeping the maximum single vibration experienced by the existing tunnel at an extremely low level.

Description

Technical Field

[0001] This invention relates to the field of vibration isolation and reduction technology for adjacent existing tunnels, specifically to a method and system for co-initiation of carbon dioxide phase change fracturing and electronic detonators. Background Technology

[0002] In urban underground space development or the reconstruction and expansion of traffic tunnels, the distance between new tunnels and existing buildings is getting closer and closer. Although traditional drill-and-blast methods are highly efficient, the shock waves and seismic waves generated by explosive explosions are unavoidable byproducts. In recent years, carbon dioxide phase change fracturing technology has been introduced into tunnel construction due to its "spark-free and low-vibration" characteristics. However, the use of carbon dioxide phase change fracturing devices alone in full-face tunnel excavation has significant limitations: carbon dioxide phase change fracturing is essentially gas wedge splitting; without a free surface, the high-pressure gas cannot effectively push away the rock, resulting in a very small fracturing range; under conditions without a free surface, the rock is not fully thrown out, and the fracturing device tube is often tightly clamped by deformed rock strata, making recovery extremely difficult and seriously affecting the cycle operation time; compared with explosives, gas expansion power is low, making it difficult to handle the cut areas of hard rock.

[0003] Therefore, there is an urgent need for a method and system for co-initiating carbon dioxide phase change fracturing and electronic detonators to overcome the shortcomings of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for co-initiating carbon dioxide phase change fracturing and electronic detonator detonation, so as to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the first aspect of this invention proposes a method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator detonation, comprising: Step 1: Using the vertical centerline of the tunnel face as a reference, divide the tunnel face into an explosive blasting zone and a carbon dioxide phase transformation fracturing zone; the carbon dioxide phase transformation fracturing zone includes a rock-breaking zone and a contour control zone. Step 2: Drill conventional blast holes in the explosive blasting zone, including slotted holes, auxiliary holes, bottom holes, and peripheral holes; drill fracturing holes and fracturing guide holes in the carbon dioxide phase change fracturing zone. Step 3: Install an electronic detonator in the conventional blast hole and a carbon dioxide phase change fracturing device in the fracturing hole. Connect the electronic detonator and the carbon dioxide phase change fracturing device excitation head to the detonation controller via the same bus. Step 4: Detonate the electronic detonator in the explosive blasting zone using the detonation controller, and detonate the slotted holes, auxiliary holes, bottom holes, and peripheral holes in sequence. After the explosive blasting zone is completed and the vibration damping interval is over, trigger the carbon dioxide phase change fracturing device in the carbon dioxide phase change fracturing zone to push the rock in the carbon dioxide phase change fracturing zone into the cavity formed by the explosive blasting zone in blocks.

[0006] Furthermore, in step 1, the explosive blasting zone is far from the existing tunnel side, while the carbon dioxide phase change-induced cracking zone is close to the existing tunnel side.

[0007] Furthermore, in step 2, the conventional borehole diameter in the explosive blasting zone is 42mm, the conventional borehole depth is 2.5m-3.0m, and the conventional borehole spacing is 40cm-50cm.

[0008] Furthermore, in step 2, the diameter of the fracturing holes in the carbon dioxide phase change fracturing zone is 90mm-110mm. The diameter of the fracturing holes needs to be adapted to the diameter of the selected carbon dioxide phase change fracturing device. Hollow PVC pipes of the same diameter are placed in the fracturing holes. The depth of the fracturing holes is 0.85 times the depth of conventional blasting holes, and the spacing between the fracturing holes is 0.8m-1.0m.

[0009] Furthermore, in step 2, the diameter of the fracture-inducing guide hole is 42mm, and it is drilled evenly at the connection line between the fracture-inducing holes according to the fracture direction.

[0010] Furthermore, step 3, installing a carbon dioxide phase change fracturing device in the fracturing orifice, includes: Install a liquid carbon dioxide phase change fracturing device with a rated energy release pressure of 230MPa-270MPa in the rock-breaking zone; Install a liquid carbon dioxide phase change fracturing device with a rated energy release pressure of 150MPa-180MPa in the contour control area.

[0011] Furthermore, in step 4, conventional emulsion explosives are used as the rock-breaking source in the explosive blasting zone, and liquid carbon dioxide phase change fracturing device is used as the rock-breaking source in the carbon dioxide phase change fracturing zone.

[0012] Furthermore, the expression for the vibration damping time ΔT in step 4 is: Where L is the distance between the newly built tunnel and the existing tunnel, and C p T represents the longitudinal wave velocity of the rock mass. decay This is an empirical value for vibration attenuation.

[0013] Furthermore, it also includes: Step 5: After the blasting is completed, start the blower and wait for the oxygen concentration to return to normal before recovering the carbon dioxide phase change fracturing device in the slag pile.

[0014] A second aspect of this invention proposes a system for the coordinated initiation of carbon dioxide phase change fracturing and electronic detonator detonation, comprising: The zoning control module is used to divide the tunnel face into an explosive blasting zone and a carbon dioxide phase transformation fracturing zone, based on the vertical centerline of the tunnel face. The carbon dioxide phase transformation fracturing zone includes a rock breaking zone and a contour control zone. The vibration damping interval calculation module is used to calculate the vibration damping interval time based on the distance between the new and existing tunnels, rock wave velocity, and empirical values ​​of vibration attenuation. The timing detonation control module is used to detonate the electronic detonators in the explosive blasting zone through the detonation controller, and sequentially detonate the slotted holes, auxiliary holes, bottom holes and peripheral holes. After the explosive blasting zone is completed and the vibration damping interval is over, the carbon dioxide phase change fracturing device in the carbon dioxide phase change fracturing zone is triggered, and the rock in the carbon dioxide phase change fracturing zone is pushed in blocks into the cavity formed by the explosive blasting zone.

[0015] The beneficial effects of the technical solution of this invention include: 1. This invention completely eliminates the use of explosives in the carbon dioxide phase change fracturing zone adjacent to the existing tunnel, instead employing gas expansion fracturing. Gas-induced fracturing has a low dominant vibration frequency and a long duration, thus eliminating the impact on the existing tunnel at its source; 2. Traditional carbon dioxide phase change fracturing is not very effective due to the large rock clamping force. This invention utilizes explosive blasting in the blasting zone to first create a cavity, giving the rock in the carbon dioxide phase change fracturing zone excellent movement space. Gas expansion only needs to overcome the tensile strength of the rock to peel it off, which greatly improves the fracturing efficiency and the fracturing device recovery rate. 3. This invention relies on the millisecond-level precision of electronic detonators to forcibly separate the time interval between explosive detonation and gas fracturing, ensuring that the vibration waveforms of the two do not overlap, so that the maximum single vibration of the existing tunnel is always controlled at an extremely low level. 4. Compared with full-face mechanical excavation or full-face carbon dioxide phase change fracturing, this invention retains the explosive blasting zone, ensuring the overall tunneling progress and balancing progress and safety. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating an embodiment of the present invention; Figure 2 This is a schematic diagram of the tunnel face region division according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the cavity creation stage according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a carbon dioxide phase change fracturing and electronic detonator co-initiation device according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a carbon dioxide phase change fracturing device for rock breaking according to an embodiment of the present invention.

[0017] In the diagram: Area A represents the explosive blasting zone, and Area B represents the carbon dioxide phase transition fracturing zone; C represents peripheral holes, D represents auxiliary holes, E represents bottom holes, F represents slotted holes, G represents central voids of slotted holes, H represents fracture-inducing holes in rock-breaking zones, I represents fracture-inducing holes in contour control zones, and J represents fracture-inducing guide voids. Labels in the diagram: 1: Directional shearing disc; 2: Liquid storage tube; 3: Charge cartridge; 4: Thick steel pipe wall; 5: Heating element; 6: Injection head; 7: Constant pressure release valve; 8: Electronic detonator; 9: Detonation controller; 10: Dividing line between Zone A and Zone B. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 This embodiment is applied to a highway tunnel expansion project. The newly built left-line tunnel is a three-lane, large-section tunnel with an excavation width of 14.5m and a height of 11.2m. Only a 6.0m thick interlocking rock column is retained between the left sidewall of the new tunnel and the existing operating left-line tunnel. Given the high traffic volume and well-developed joints in the rock column within the existing tunnel, it is required that the vibration velocity of the existing tunnel sidewall be controlled below 2.0cm / s during blasting operations, and damage to the interlocking rock column is strictly prohibited.

[0020] The first aspect of this invention proposes a method for synergistic initiation of carbon dioxide phase change-induced fracturing and electronic detonator detonation, such as... Figure 1 As shown, the method includes: Step 1: Using the vertical centerline of the tunnel face as a reference, divide the tunnel face into an explosive blasting zone and a carbon dioxide phase transformation fracturing zone; the carbon dioxide phase transformation fracturing zone includes a rock-breaking zone and a contour control zone. Furthermore, in step 1, the explosive blasting zone is far from the existing tunnel side, while the carbon dioxide phase change-induced cracking zone is close to the existing tunnel side.

[0021] In this embodiment, before construction of the new tunnel face, ground-penetrating radar or advanced drilling methods are used to accurately determine the relative spatial position of the new tunnel and the existing tunnel, including distance and azimuth. Acoustic wave testing is conducted on the rock mass at the tunnel face to obtain the longitudinal wave velocity C of the rock mass. p This is used for subsequent calculations of the vibration wave decay time. Blasting control lines are drawn on the tunnel face using red paint.

[0022] like Figure 2 As shown, the explosive blasting zone is located on the right side and the central core area of ​​the working face, accounting for about 75% of the total area, while the carbon dioxide phase transformation cracking zone is located on the left side of the working face.

[0023] Step 2: Drill conventional blast holes in the explosive blasting zone, including slotted holes, auxiliary holes, bottom holes, and peripheral holes; drill fracturing holes and fracturing guide holes in the carbon dioxide phase change fracturing zone. Furthermore, in step 2, the conventional borehole diameter in the explosive blasting zone is 42mm, the conventional borehole depth is 2.5m-3.0m, and the conventional borehole spacing is 40cm-50cm.

[0024] Furthermore, in step 2, the diameter of the fracturing holes in the carbon dioxide phase change fracturing zone is 90mm-110mm. The diameter of the fracturing holes needs to be adapted to the diameter of the selected carbon dioxide phase change fracturing device. Hollow PVC pipes of the same diameter are placed in the fracturing holes. The depth of the fracturing holes is 0.85 times the depth of conventional blasting holes, and the spacing between the fracturing holes is 0.8m-1.0m.

[0025] In this embodiment, as Figure 3 As shown, a central cut hole G is set at the center of the tunnel as the free face for cut blasting. This hole is not loaded with explosives. The cut hole F is filled with emulsion explosives. The auxiliary holes D are arranged around the cut holes in the upper half of the tunnel. The bottom hole E is arranged parallel downwards at the bottom of the tunnel. The peripheral holes C are arranged along the tunnel outline.

[0026] In the explosive blasting zone, 42mm blast holes were drilled using a rock drilling rig, with a hole depth of 3.0m, and wedge-shaped slots were used.

[0027] In this embodiment, rock-breaking and fracturing holes are arranged in the middle area on the left side of the tunnel, and a row of contour-controlled fracturing holes are arranged vertically along the left side contour line of the tunnel. 110mm fracturing holes are drilled using a down-the-hole drill, with a hole depth of 2.55m, which is slightly less than the depth of the blasting holes in the explosive blasting zone to prevent jamming. The hole spacing is 1.0m.

[0028] A hollow PVC pipe of the same diameter is placed in the fracturing hole to prevent falling debris from blocking the directional shear plate 1 during the blasting of the explosive blasting zone. The depth of the fracturing hole in the carbon dioxide phase change fracturing zone should be slightly smaller than the depth of the conventional blasting hole in the explosive blasting zone, and the hole depth should be 0.85 times that of the conventional blasting hole to prevent the bottom of the fracturing device from being damaged by the blasting of the explosive blasting zone.

[0029] Furthermore, in step 2, the diameter of the fracture-inducing guide hole is 42mm, and it is uniformly drilled from the connection line between the fracture holes according to the fracture direction.

[0030] In this embodiment, a 42mm diameter fracture guide hole is drilled using a rock drilling rig along the cutting line of the carbon dioxide phase change fracture device in the carbon dioxide phase change fracture zone. This is to precisely control the cutting direction of the high-pressure gas in the rock breaking stage and the contour control stage, which not only guides the fracture but also controls the contour surface of the tunnel after fracture.

[0031] Step 3: Install an electronic detonator in the conventional blast hole and a carbon dioxide phase change fracturing device in the fracturing hole. Connect the electronic detonator and the carbon dioxide phase change fracturing device excitation head to the detonation controller via the same bus. Specifically, such as Figure 4 As shown, the carbon dioxide phase change fracturing device includes a directional shear plate 1, a liquid storage tube 2, a heating element 5, a liquid injection head 6, and a constant pressure relief valve 7; The carbon dioxide phase change fracturing device uses a thick steel pipe wall 4 to provide a high-strength pressure-bearing shell, which can withstand the huge pressure generated by vaporization and ensure operational safety. The directional shear plate 1 has a pre-set weak or guiding structure to control the direction and shape of the high-pressure gas ejection, so as to achieve directional fracturing. The liquid storage pipe 2 is the container for the phase change to occur, which is used to seal and store liquid carbon dioxide. The heating element 5 is used to heat the liquid carbon dioxide to cause it to undergo a phase change. The injection head 6 has a filling interface with a one-way valve, which is used to safely inject liquid carbon dioxide into the liquid storage pipe 2 for reuse. The constant pressure relief valve 7 is a mechanical pressure control element that opens instantly after the set pressure is reached to release high-pressure gas. It remains sealed when the pressure is below the threshold to prevent premature leakage.

[0032] The carbon dioxide phase change fracturing device heats the liquid carbon dioxide in the storage tube 2 through the heating element 5. After being heated, the liquid carbon dioxide rapidly vaporizes and undergoes a phase change, expanding in volume and generating a large amount of pressure, which is released instantaneously through the directional shear plate 1 to achieve the rock-breaking effect.

[0033] The explosive blasting zone assembly includes a charge cartridge 3 and an electronic detonator 8.

[0034] Furthermore, step 3, installing a carbon dioxide phase change fracturing device in the fracturing orifice, includes: Install a liquid carbon dioxide phase change fracturing device with a rated energy release pressure of 230MPa-270MPa in the rock-breaking zone; Install a liquid carbon dioxide phase change fracturing device with a rated energy release pressure of 150MPa-180MPa in the contour control area.

[0035] In this embodiment, the charge cylinder 3 in the explosive blasting zone is filled with No. 2 rock emulsion explosive using a non-coupled charge structure, and the amount of explosive per hole varies from 0.8 kg to 2.4 kg depending on the location.

[0036] In the rock-breaking zone of the carbon dioxide phase change fracturing zone, a liquid carbon dioxide phase change fracturing device with a rated energy release pressure of 230MPa-270MPa is selected to complete the fracturing and excavation of large-volume rock masses. In the contour control zone of the carbon dioxide phase change fracturing zone, a liquid carbon dioxide phase change fracturing device with a rated energy release pressure of 150MPa-180MPa is used to ensure that the tunnel produces a smooth contour after fracturing, and to prevent over-excavation and under-excavation.

[0037] A dedicated electrothermal excitation head adapted to the electronic detonator 8 detonation system is installed inside the heating tube of the fracturing device. This excitation head is equipped with an electronic detonator 8 chip and can accept delay commands. The fracturing device is then inserted into the bottom of the borehole, and the borehole opening is secured with a dedicated barbed anti-flying clamp or a steel pressure cap to prevent the fracturing device from impacting personnel. All fracturing holes are then sealed with high-quality stemming clay to prevent air leakage.

[0038] A Type-110 carbon dioxide phase change fracturing device was installed in the carbon dioxide phase change fracturing zone. Each tube was filled with 5.0 kg of liquid carbon dioxide. By changing the shear blades of different thicknesses, the energy release pressures in the rock-breaking fracturing zone and the contour-controlled fracturing zone were controlled to be 230 MPa and 150 MPa, respectively. A PVC pipe of equal diameter was inserted to prevent blockage of the directional shear blade 1. The heating tube inside the fracturing device was pre-installed with a special excitation head adapted to the electronic detonator 8 detonation system. All fracturing holes were sealed with high-quality stemming material to prevent gas leakage.

[0039] All electronic detonators 8 in the explosive blasting zone and all excitation heads in the carbon dioxide phase change fracturing zone are connected to the detonator via the same bus.

[0040] Step 4: Detonate the electronic detonator 8 in the explosive blasting zone through the detonation controller 9, and detonate the slotted holes, auxiliary holes, bottom holes and peripheral holes in sequence. After the explosive blasting zone is completed, wait for the vibration damping interval time, and trigger the carbon dioxide phase change fracturing device in the carbon dioxide phase change fracturing zone to push the rock in the carbon dioxide phase change fracturing zone into the cavity formed by the explosive blasting zone in blocks.

[0041] In this embodiment, as Figure 3 As shown, the sequential detonation of the cut hole, auxiliary hole, bottom hole, and peripheral holes includes: the cut hole F excavates a cavity in the tunnel; the auxiliary hole D further expands the area of ​​the tunnel cavity; the bottom hole E expands the area of ​​the cavity at the bottom of the tunnel and overturns and piles up the crushed stone, providing conditions for the subsequent excavation of the peripheral holes; the peripheral hole C completes the control of the tunnel excavation outline, forming a smooth blasting surface.

[0042] Furthermore, in step 4, conventional emulsion explosives are used as the rock-breaking source in the explosive blasting zone, and liquid carbon dioxide phase change fracturing device is used as the rock-breaking source in the carbon dioxide phase change fracturing zone.

[0043] In this embodiment, as Figure 5 As shown, three fracturing holes are arranged in a ring around the tunnel center towards the contour surface in area B. Fracturing guide holes are connected in the middle of the fracturing holes to induce the rock-breaking position of high-pressure gas. H represents the fracturing hole in the rock-breaking area, which aims to complete large-area fracturing and rock-breaking in area B after a large cavity is formed in area A; I is the contour control fracturing hole, which aims to control the tunnel contour after rock breaking.

[0044] Using the millisecond-level delay function of the electronic detonator 8, the following detonation procedure is set: The first stage is to create a cavity in the explosive blasting zone: the slotted holes, auxiliary holes, base holes and peripheral holes are detonated in sequence. The detonation time of the slotted holes is set to 0ms, the detonation time of the auxiliary holes is 60ms, the detonation time of the base holes is 120ms, and the detonation time of the peripheral holes is 180ms.

[0045] The second stage is the waiting period for vibration attenuation: the interval time is set to ΔT = 120ms. During this period, there is no detonation action, and the seismic waves in the explosive blast zone are allowed to completely attenuate.

[0046] The third stage is fracturing in the carbon dioxide phase change fracturing zone: the initial detonation time of the carbon dioxide phase change fracturing zone is 300ms. A delay of 25ms is set between each fracturing hole in the carbon dioxide phase change fracturing zone, and then 300ms, 325ms, 350ms, etc., to detonate the fracturing devices in the rock breaking zone and the contour control zone in sequence.

[0047] Furthermore, the expression for the vibration damping time ΔT in step 4 is: Where L is the distance between the newly built tunnel and the existing tunnel, and C p T represents the longitudinal wave velocity of the rock mass. decay This is an empirical value for vibration attenuation.

[0048] Specifically, the longitudinal wave velocity C of the rock mass p It can be calculated using the following formula: ; Among them, L p T represents the hole spacing. p This indicates the propagation time of the wave.

[0049] When blasting is performed during tunnel excavation, the time ΔT0 for the shock wave to propagate to a nearby tunnel and return to the excavated tunnel is: ; Furthermore, it also includes: Step 5: After the blasting is completed, start the blower and enter the tunnel after the oxygen concentration returns to normal. Recover the carbon dioxide phase change fracturing device in the slag heap.

[0050] Example 2 A second aspect of this invention proposes a system for the coordinated initiation of carbon dioxide phase change fracturing and electronic detonator detonation, comprising: The zoning control module is used to divide the tunnel face into an explosive blasting zone and a carbon dioxide phase transformation fracturing zone, based on the vertical centerline of the tunnel face. The carbon dioxide phase transformation fracturing zone includes a rock breaking zone and a contour control zone. The vibration damping interval calculation module is used to calculate the vibration damping interval time based on the distance between the new and existing tunnels, rock wave velocity, and empirical values ​​of vibration attenuation. The timing detonation control module is used to detonate the electronic detonators in the explosive blasting zone through the detonation controller, and sequentially detonate the slotted holes, auxiliary holes, bottom holes and peripheral holes. After the explosive blasting zone is completed and the vibration damping interval is over, the carbon dioxide phase change fracturing device in the carbon dioxide phase change fracturing zone is triggered, and the rock in the carbon dioxide phase change fracturing zone is pushed in blocks into the cavity formed by the explosive blasting zone.

[0051] The contents not described in detail in this specification are prior art known to those skilled in the art. Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0052] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0053] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0054] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.

Claims

1. A method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator, characterized in that, include: Step 1: Using the vertical centerline of the tunnel face as a reference, divide the tunnel face into an explosive blasting zone and a carbon dioxide phase transformation fracturing zone; the carbon dioxide phase transformation fracturing zone includes a rock-breaking zone and a contour control zone. Step 2: Drill conventional blast holes in the explosive blasting zone, including slotted holes, auxiliary holes, bottom holes, and peripheral holes; drill fracturing holes and fracturing guide holes in the carbon dioxide phase change fracturing zone. Step 3: Install an electronic detonator in the conventional blast hole and a carbon dioxide phase change fracturing device in the fracturing hole. Connect the electronic detonator and the carbon dioxide phase change fracturing device excitation head to the detonation controller via the same bus. Step 4: Detonate the electronic detonator in the explosive blasting zone using the detonation controller, and detonate the slotted holes, auxiliary holes, bottom holes, and peripheral holes in sequence. After the explosive blasting zone is completed and the vibration damping interval is over, trigger the carbon dioxide phase change fracturing device in the carbon dioxide phase change fracturing zone to push the rock in the carbon dioxide phase change fracturing zone into the cavity formed by the explosive blasting zone in blocks.

2. The method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator according to claim 1, characterized in that, In step 1, the explosive blasting zone is far from the existing tunnel side, while the carbon dioxide phase change cracking zone is close to the existing tunnel side.

3. The method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator according to claim 1, characterized in that, In step 2, the conventional borehole diameter in the explosive blasting zone is 42mm, the conventional borehole depth is 2.5m-3.0m, and the conventional borehole spacing is 40cm-50cm.

4. The method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator according to claim 1, characterized in that, In step 2, the diameter of the fracturing holes in the carbon dioxide phase change fracturing zone is 90mm-110mm. The diameter of the fracturing holes must be adapted to the diameter of the selected carbon dioxide phase change fracturing device. Hollow PVC pipes of the same diameter are placed in the fracturing holes. The depth of the fracturing holes is 0.85 times the depth of conventional blasting holes, and the spacing between the fracturing holes is 0.8m-1.0m.

5. The method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator according to claim 1, characterized in that, In step 2, the diameter of the fracture-inducing guide hole is 42mm, and it is drilled evenly along the line connecting the fracture holes according to the fracture direction.

6. The method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator according to claim 1, characterized in that, Step 3, which involves installing a carbon dioxide phase change fracturing device in the fracturing orifice, includes: Install a liquid carbon dioxide phase change fracturing device with a rated energy release pressure of 230MPa-270MPa in the rock-breaking zone; Install a liquid carbon dioxide phase change fracturing device with a rated energy release pressure of 150MPa-180MPa in the contour control area.

7. The method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator according to claim 1, characterized in that, In step 4, conventional emulsion explosives are used as the rock-breaking source in the explosive blasting zone, and liquid carbon dioxide phase change fracturing device is used as the rock-breaking source in the carbon dioxide phase change fracturing zone.

8. The method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator according to claim 1, characterized in that, The expression for the vibration damping time ΔT in step 4 is: Where L is the distance between the newly built tunnel and the existing tunnel, and C p T represents the longitudinal wave velocity of the rock mass. decay This is an empirical value for vibration attenuation.

9. The method for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator according to claim 1, characterized in that, Also includes: Step 5: After the blasting is completed, start the blower and wait for the oxygen concentration to return to normal before recovering the carbon dioxide phase change fracturing device in the slag pile.

10. A system for synergistic initiation of carbon dioxide phase change fracturing and electronic detonator, characterized in that, include: The zoning control module is used to divide the tunnel face into an explosive blasting zone and a carbon dioxide phase change fracturing zone, based on the vertical centerline of the tunnel face. The carbon dioxide phase transformation-induced fracturing zone includes a rock-breaking zone and a contour control zone; The vibration damping interval calculation module is used to calculate the vibration damping interval time based on the distance between the new and existing tunnels, rock wave velocity, and empirical values ​​of vibration attenuation. The timing detonation control module is used to detonate the electronic detonators in the explosive blasting zone through the detonation controller, and sequentially detonate the slotted holes, auxiliary holes, bottom holes and peripheral holes. After the explosive blasting zone is completed and the vibration damping interval is over, the carbon dioxide phase change fracturing device in the carbon dioxide phase change fracturing zone is triggered, and the rock in the carbon dioxide phase change fracturing zone is pushed in blocks into the cavity formed by the explosive blasting zone.

Images