A fast tunneling method for hard rock tunnels with integrated drilling, pressure and excavation

Abstract

The present invention discloses a method for rapid tunneling in hard rock using an integrated drilling, pressure, and excavation system. This method belongs to the technical field of rapid tunneling in coal mines. The method comprises the following steps: monitoring the spatial distribution of hydraulic fractures and designing a hydraulic fracturing scheme; using an integrated drilling, pressure, and excavation system to construct a hydraulic fracturing borehole and perform hydraulic fracturing; and, after hydraulic fracturing, cutting and transporting the rock mass within the fracturing section of the tunnel to complete the tunneling operation. The method can reduce the strength and fragmentation of hard rock, improve its cuttability, lower dust concentration in the working space, save construction time, reduce labor intensity, and improve the efficiency of tunneling in hard rock tunnels.

Description

Technical Field

[0001] The present invention relates to the technical field of rapid tunneling of coal mine tunnels, and in particular to a rapid tunneling method for hard rock tunnels with integrated drilling, pressure and tunneling. Background Art

[0002] When excavating rock tunnels in coal mines, blasting or tunnel boring machines (TBMs) are typically used to break the rock. Blasting consumes a lot of explosives, is a complex process, is labor-intensive, and reduces the safety factor of the working surface. When using tunnel boring machines (TBMs) to cut rock, the hardness of the rock makes them slow to break, resulting in severe cutter wear and high dust concentrations. Consequently, traditional methods are inefficient in rock tunnel excavation, slowing down tunnel excavation speeds and hindering safe and efficient mine production. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned existing technologies and provide a method for rapid tunneling of hard rock tunnels with integrated drilling, pressure and excavation. The method adopts integrated drilling, pressure and excavation equipment to hydraulically fracture the hard rock in the tunnel, thereby reducing the strength and size of the rock to be excavated, improving the cuttability of the hard rock, and accelerating the tunneling speed.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A method for rapid tunneling in a hard rock tunnel using integrated drilling, pressure and excavation, comprising the following steps: 1. opening a fracturing hole and performing hydraulic fracturing; opening a fracturing hole at the center of the hard rock of the tunnel to be excavated, injecting high-pressure water into the fracturing hole through a high-pressure water pump for hydraulic fracturing, and generating hydraulic fractures around the fracturing hole after hydraulic fracturing. Since the expansion direction of the hydraulic fractures is perpendicular to the direction of the minimum principal stress, the hydraulic fractures around the fracturing hole basically develop in one direction; 2. opening a monitoring hole and determining the main expansion direction of the hydraulic fractures; opening a plurality of monitoring holes evenly around the fracturing hole, with the depth of the monitoring holes being equal to the depth of the fracturing hole, and the distance between each monitoring hole and the fracturing hole being 1 to 1.5 m; placing a borehole transient electromagnetic instrument in the monitoring hole, and monitoring the spatial distribution of the hydraulic fractures in the monitoring hole after hydraulic fracturing by the borehole transient electromagnetic instrument. , the main expansion direction of the hydraulic fractures is known according to the distribution of the hydraulic fractures; step 3, three hydraulic fracturing boreholes are evenly opened according to the main expansion direction of the hydraulic fractures; in order to produce relatively evenly distributed hydraulic fractures in the hard rock, the three hydraulic fracturing boreholes are on the same straight line, and the line connecting the boreholes is perpendicular to the main expansion direction of the hydraulic fractures. A hydraulic fracturing borehole is arranged at the center of the tunnel section, and the other two hydraulic fracturing boreholes are arranged 0.5~1.5m away from the tunnel side; step 4, high-pressure water is injected into the three hydraulic fracturing boreholes for hydraulic fracturing, so that a large number of hydraulic fractures are generated in the hard rock, and the rock mass in the hard rock fracturing section is cut and transported using comprehensive excavation equipment; step 5, according to the rock tunnel excavation requirements, steps 2, 3 and 4 are repeated to complete the rock tunnel excavation operation.

[0006] As a further preferred embodiment of the present invention, the depth of the intermediate fracture hole and the monitoring hole in steps 1 and 2 is 10 meters, the fracturing point is located in the middle of the fracture hole, that is, at a length of 5 meters, the fracturing point is where high-pressure water is injected, and the distances from each monitoring hole to the fracture hole are equal. In order to more easily obtain the spatial distribution of hydraulic fractures around the fracture hole after hydraulic fracturing, before the borehole transient electromagnetic instrument in step 2 is placed in the monitoring hole, water is continuously injected into the fracture hole for 3 to 5 minutes to increase the water content in the hydraulic fracture. During the water injection process, the orifice is blocked to prevent a large amount of water from flowing out of the orifice.

[0007] As a further preferred embodiment of the present invention, when hydraulic fracturing is performed in step 3, the central hole is fractured first, and then the peripheral holes are fractured, and each hole is fractured one by one; the hydraulic fracturing drilling length is 15 to 20 meters, and the fracturing is performed every 3 to 4 meters from the bottom of the hole to the hole mouth, and the fracturing time is 5 minutes. During fracturing, the hole mouth is blocked so that water can fully soak and soften the hard rock.

[0008] As a further preferred embodiment of the present invention, a data storage pressure transmitter is used to record the pressure of the high-pressure water pump during the fracturing process.

[0009] As a further preferred embodiment of the present invention, when encountering a significant change in geological conditions or a large change in the pressure of the high-pressure water pump during excavation in step 5, steps 1 to 5 are repeated to re-monitor the main direction of the hydraulic fractures and perform hydraulic fracturing.

[0010] As a further preferred embodiment of the present invention, the comprehensive tunneling equipment described in step 4 is an integrated drilling, pressure and tunneling comprehensive tunneling equipment, including a tunneling machine and a hydraulic fracturing system placed on the tunneling machine, and the hydraulic fracturing system includes two drill arms located on both sides of the tunneling machine and a high-pressure water pump arranged on the tunneling machine.

[0011] As a further preferred embodiment of the present invention, the drill arm is a six-degree-of-freedom telescopic drill arm.

[0012] As a further preferred embodiment of the present invention, when the tunnel boring machine performs the cutting operation, the drum of the tunnel boring machine starts from the highest hydraulic fracturing borehole side and cuts the entire section from top to bottom.

[0013] As a further preferred embodiment of the present invention, an interlocking device is provided between the drum of the roadheader and the drill arm of the hydraulic fracturing system.

[0014] The present invention has the following beneficial effects:

[0015] (1) By hydraulically fracturing hard rocks, their strength and blockiness are reduced, and the cuttability of hard rocks is improved. At the same time, due to the effect of water, the dust concentration in the working space is reduced.

[0016] (2) The integrated construction of drilling, fracturing and tunneling can save construction time, reduce the labor intensity of workers and improve the efficiency of hard rock tunneling. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the arrangement of the crack-inducing holes and monitoring holes of the present invention;

[0018] Figure 2 It is a schematic diagram of hydraulic fracturing boreholes and hydraulic fracture distribution;

[0019] Figure 3 It is a schematic diagram of the overall structure of the integrated drilling, pressure and excavation equipment.

[0020] Among them are: 1-hard rock, 2-fracture hole, 3-monitoring hole, 4-hydraulic fracture, 5-hydraulic fracturing drilling hole, 6-integrated drilling, pressure and excavation equipment, 7-tunneling machine, 8-drill arm, 9-high-pressure water pump, 10-drum, 11-broken rock, 12-shovel, 13-transportation equipment. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific preferred embodiments.

[0022] In the description of the present invention, it should be understood that the terms "left side," "right side," "upper," "lower," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Terms such as "first" and "second" do not indicate the importance of components and therefore should not be construed as limitations on the present invention. The specific dimensions used in this embodiment are intended only to illustrate the technical solution and do not limit the scope of protection of the present invention.

[0023] like Figure 1-Figure 3 As shown in the figure, a fast tunneling method for hard rock tunnels with integrated drilling, pressure and excavation is shown in the figure. Figure 1 As shown, step 1, opening a fracturing hole 2 and performing hydraulic fracturing; a fracturing hole 2 is opened at the center of the hard rock 1 of the tunnel to be excavated by a drill arm 8, and high-pressure water is injected into the fracturing hole 2 by a high-pressure water pump 9 to perform hydraulic fracturing. After hydraulic fracturing, hydraulic fractures 4 are generated around the fracturing hole 2. Since the expansion direction of the hydraulic fractures 4 is perpendicular to the direction of the minimum principal stress, the hydraulic fractures 4 around the fracturing hole 2 basically develop along one direction in the hard rock 1.

[0024] Step 2: Figure 1 As shown, monitoring holes 3 are opened to measure the main expansion direction of hydraulic fractures 4. Multiple monitoring holes 3 are evenly distributed around the fracture hole 2. The depth of each monitoring hole 3 is equal to that of the fracture hole 2, and the distance between each monitoring hole 3 and the fracture hole 2 is equal. Preferably, there are four monitoring holes 3. Since the roadway height is generally about 3 to 3.5 meters, the distance between each monitoring hole 3 and the fracture hole 2 is about 1 to 1.5 meters.

[0025] Then, the borehole transient electromagnetic instrument is placed in the monitoring hole 3. The borehole transient electromagnetic instrument can monitor the spatial distribution of the hydraulic fractures 4 in the monitoring hole 3 after hydraulic fracturing by measuring the change in the resistivity of the hard rock 1, and the main expansion direction of the hydraulic fractures 4 can be obtained based on the distribution of the hydraulic fractures 4.

[0026] Step 3: Figure 2 As shown, three hydraulic fracturing boreholes 5 are evenly opened according to the main expansion direction of the hydraulic fractures 4; in order to produce relatively evenly distributed hydraulic fractures 4 in the hard rock 1, the three hydraulic fracturing boreholes 5 are all on the same straight line, and the line connecting the three hydraulic fracturing boreholes 5 is perpendicular to the main expansion direction of the hydraulic fractures 4. One hydraulic fracturing borehole 5 is arranged at the center of the tunnel section, and the other two hydraulic fracturing boreholes 5 are arranged 0.5~1.5m away from the side of the tunnel.

[0027] Step 4: Inject high-pressure water into the three hydraulic fracturing boreholes 5 to perform hydraulic fracturing, thereby generating a large number of hydraulic fractures 4 in the hard rock, and use a fully integrated excavation device to cut and transport the rock mass within the fracturing section of the hard rock 1;

[0028] Step 5: Repeat steps 2, 3, and 4 according to the rock tunnel excavation requirements to complete the rock tunnel excavation operation.

[0029] The depth of the intermediate fracture hole 2 and the monitoring hole 3 in steps 1 and 2 is 10 meters. The fracturing point is located in the middle of the fracture hole 2, that is, at a length of 5 meters. The fracturing point is where high-pressure water is injected. The distances between each monitoring hole 3 and the fracture hole 2 are equal. In order to more easily obtain the spatial distribution of the hydraulic fractures 4 around the fracture hole 2 after hydraulic fracturing, before the borehole transient electromagnetic instrument in step 2 is placed in the monitoring hole 3, water is continuously injected into the fracture hole 2 for 3 to 5 minutes to increase the water content in the hydraulic fracture 4. During the water injection process, the orifice is blocked to prevent a large amount of water from flowing out of the orifice.

[0030] During hydraulic fracturing in step 3, the hydraulic fracturing borehole 5 at the center of the tunnel section is first fractured, followed by fracturing of the surrounding hydraulic fracturing boreholes 5. After a hydraulic fracturing borehole 5 is opened by the drill arm 8, fracturing is immediately performed, and then the remaining hydraulic fracturing boreholes 5 are opened and fractured again. The hydraulic fracturing boreholes 5 are 15 to 20 meters long, and fracturing is performed every 3 to 4 meters from the bottom of the hole to the hole mouth, for a fracturing time of 5 minutes. During fracturing, the hole mouth is blocked to allow water to fully soak and soften the hard rock 1.

[0031] During the hydraulic fracturing process, a data storage type pressure transmitter is used to record the pressure of the high pressure water pump 9.

[0032] If, during tunneling in step 5, the geological conditions change significantly or the pressure of the high-pressure water pump 9 changes significantly, steps 1 through 5 are repeated to re-monitor the primary propagation direction of the hydraulic fractures 4 and perform hydraulic fracturing. Significant changes in geological conditions can be detected by the cutting efficiency of the tunneling machine 7 or by pressure changes displayed by the pressure transmitter.

[0033] The tunneling equipment described in step 4 is an integrated drilling, pressure-drilling, and tunneling (DWD) tunneling system 6, comprising a roadheader 7 and a hydraulic fracturing system mounted on the roadheader 7. The hydraulic fracturing system comprises two drill arms 8 positioned on either side of the roadheader 7 and a high-pressure water pump 9 mounted on the roadheader 7. The roadheader 7 also includes a drum 10, a transport device 13, and a shovel 12. During the cutting operation, the drum 10 cuts the entire section downward, starting from the highest hydraulic fracturing borehole 5. The shovel 12 collects the crushed rock blocks 11, and the transport device 13 transports the crushed rock blocks 11.

[0034] The drill arm 8 is a six-degree-of-freedom telescopic drill arm, which can facilitate drilling in various directions and depths.

[0035] In order to avoid collision between the drum 10 and the drill arm 8 due to misoperation, an interlocking device is used between the two to improve the safety of the operation process.

[0036] Through the above method, the present invention uses the integrated drilling, pressure and excavation equipment 6 to hydraulically fracture the hard rock 1 during the tunnel excavation process, thereby improving the cuttability of the hard rock, reducing the labor intensity of workers and the dust concentration in the working space, improving the excavation efficiency, and accelerating the tunnel excavation speed.

[0037] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the scope of protection of the present invention.

Claims

1. A method for rapid tunneling in hard rock tunnels using an integrated drilling, pressure and excavation method, characterized by: Step 1, opening a fracturing hole (2) and performing hydraulic fracturing; opening a fracturing hole (2) at the center of the hard rock (1) of the tunnel to be excavated, injecting high-pressure water into the fracturing hole (2) through a high-pressure water pump (9) to perform hydraulic fracturing, and generating hydraulic fractures (4) around the fracturing hole (2) after hydraulic fracturing. Since the expansion direction of the hydraulic fractures (4) is perpendicular to the direction of the minimum principal stress, the hydraulic fractures around the fracturing hole (2) will basically develop in one direction; Step 2, opening a monitoring hole (3) and determining the main expansion direction of the hydraulic fracture (4); a plurality of monitoring holes (3) are evenly opened around the fracture hole (2), the depth of the monitoring hole (3) is equal to the depth of the fracture hole (2), and the distance between each monitoring hole (3) and the fracture hole (2) is 1 to 1.5 m; placing a borehole transient electromagnetic instrument in the monitoring hole (3), and monitoring the spatial distribution of the hydraulic fracture (4) in the monitoring hole (3) after hydraulic fracturing by the borehole transient electromagnetic instrument, and knowing the main expansion direction of the hydraulic fracture (4) according to the distribution of the hydraulic fracture (4); Step 3, three hydraulic fracturing boreholes (5) are evenly opened according to the main expansion direction of the hydraulic fracture (4); in order to generate relatively evenly distributed hydraulic fractures (4) in the hard rock (1), the three hydraulic fracturing boreholes (5) are located on the same straight line, the connecting line of the boreholes is perpendicular to the main expansion direction of the hydraulic fracture (4), one hydraulic fracturing borehole (5) is arranged at the center of the tunnel section, and the other two hydraulic fracturing boreholes (5) are arranged at 0.5 to 1.5 m from the tunnel side; Step 4: injecting high-pressure water into the three hydraulic fracturing boreholes (5) to perform hydraulic fracturing, thereby generating a large number of hydraulic fractures (4) in the hard rock (1), and using a comprehensive excavation device to cut and transport the rock mass in the fracturing section of the hard rock (1); Step 5: Repeat steps 2, 3, and 4 according to the rock tunnel excavation requirements to complete the rock tunnel excavation operation.

2. The method for rapid tunneling in hard rock tunnels with integrated drilling, pressure-drilling and excavation according to claim 1, characterized in that: The depth of the middle fracture hole (2) and the monitoring hole (3) in step 1 and step 2 is 10 meters. The fracturing point is located in the middle of the fracture hole (2), that is, at a length of 5 meters. The fracturing point is the point where high-pressure water is injected. The distances between each monitoring hole (3) and the fracture hole (2) are equal. In order to more easily obtain the spatial distribution of the hydraulic fractures (4) around the fracture hole (2) after hydraulic fracturing, before the borehole transient electromagnetic instrument in step 2 is placed in the monitoring hole (3), water is continuously injected into the fracture hole (2) for 3 to 5 minutes to increase the water content in the hydraulic fracture (4). During the water injection process, the hole mouth is blocked to prevent a large amount of water from flowing out of the hole mouth.

3. The method for rapid tunneling in hard rock tunnels with integrated drilling, pressure and excavation according to claim 2, characterized in that: When hydraulic fracturing is performed in step 3, the central hydraulic fracturing borehole (5) is first fractured, and then the peripheral hydraulic fracturing boreholes (5) are fractured, and each hole is fractured one by one; the hydraulic fracturing borehole (5) is 15 to 20 meters long, and fractures are performed every 3 to 4 meters from the bottom of the hole to the hole mouth, and the fracturing time is 5 minutes. During fracturing, the hole mouth is blocked so that water can fully soak and soften the hard rock (1).

4. The method for rapid tunneling in hard rock tunnels with integrated drilling pressure and tunneling according to claim 3, characterized in that: During the fracturing process, a data storage type pressure transmitter is used to record the pressure of the high pressure water pump (9).

5. The method for rapid tunneling in hard rock tunnels with integrated drilling, pressure and excavation according to claim 1, characterized in that: When encountering a significant change in geological conditions or a large change in the pressure of the high-pressure water pump (9) during excavation in step 5, repeat steps 1 to 5, re-monitor the main direction of the hydraulic fracture (4) and perform hydraulic fracturing.

6. The method for rapid tunneling in hard rock tunnels with integrated drilling, pressure-drilling and excavation according to claim 1, characterized in that: The comprehensive excavation equipment described in step 4 is a drilling, pressure and excavation integrated comprehensive excavation equipment (6), which includes a tunneling machine (7) and a hydraulic fracturing system placed on the tunneling machine (7), and the hydraulic fracturing system includes two drill arms (8) located on both sides of the tunneling machine (7) and a high-pressure water pump (9) arranged on the tunneling machine (7).

7. The method for rapid tunneling in hard rock tunnels with integrated drilling, pressure-drilling and excavation according to claim 6, characterized in that: The drill arm (8) is a six-degree-of-freedom telescopic drill arm.

8. The method for rapid tunneling in hard rock tunnels with integrated drilling, pressure-drilling and excavation according to claim 6, characterized in that: When the tunnel boring machine (7) performs cutting operations, the drum (10) of the tunnel boring machine (7) starts cutting the entire cross section from top to bottom starting from one side of the highest hydraulic fracturing borehole (5).

9. The method for rapid tunneling in hard rock tunnels with integrated drilling, pressure-drilling and excavation according to claim 6, characterized in that: An interlocking device is provided between the drum (10) of the tunnel boring machine (7) and the drill arm (8) of the hydraulic fracturing system.

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