Excavation method of underground powerhouse access tunnel and ventilation and safety tunnel

Abstract

The invention relates to an excavation method for an underground powerhouse access tunnel and a ventilation and safety tunnel. The method is suitable for water conservancy and hydropower engineering. According to the technical scheme, the method comprises the following steps that S1, TBM equipment is used for conducting continuous tunneling on the first side, the peripheral side and the second side of a main power house in sequence, and a first TBM tunneling tunnel section, a second TBM tunneling tunnel section and a third TBM tunneling tunnel section are formed correspondingly; s2, excavating from the second side of the main power house to the third TBM tunneling hole section by using a drilling and blasting method to form a drilling and blasting hole section; s3, receiving and dismounting the TBM equipment at the intersection of the third TBM tunneling hole section and the drilling and blasting hole section, and transporting and returning the TBM equipment through the drilling and blasting hole section; and S4, the first TBM tunneling tunnel section and the third TBM tunneling tunnel section are excavated in an expanding mode through a drilling and blasting method till permanent sections are achieved, so that the first TBM tunneling tunnel section is excavated in an expanding mode to form a factory entering traffic tunnel, the second TBM tunneling tunnel section forms a drainage gallery, and the third TBM tunneling tunnel section is excavated in an expanding mode and matched with the drilling and blasting tunnel section to form a ventilation and safety tunnel.

Description

Technical Field

[0001] The present invention relates to the technical field of water conservancy and hydropower engineering, in particular to a method for excavating an underground powerhouse entrance traffic tunnel and a ventilation and safety tunnel. Background Art

[0002] Pumped storage is the most technologically mature, economically optimal, and most suitable for large-scale development green, low-carbon, clean, and flexible power source for the power system. It is an urgent requirement for building a new power system with new energy as the main body, an important support for ensuring power supply and safe and stable operation, and an important guarantee for the large-scale development of renewable energy.

[0003] The underground powerhouse's ventilation and safety tunnel and access tunnel, serving as construction access routes for the underground powerhouse, are key line items that restrict the pumped-storage power station's power generation schedule. Accelerating their construction can effectively shorten the project's construction period. Traditionally, these tunnels have been excavated using the drill-and-blast method, which has a low degree of mechanization, requires a high level of labor, and results in a long construction period. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: in view of the above-mentioned problems, a method for excavating an underground factory entrance traffic tunnel and a ventilation and safety tunnel is provided.

[0005] The technical solution adopted by the present invention is: a method for excavating an underground factory entrance traffic tunnel and a ventilation and safety tunnel, comprising the following steps: S1. Use TBM equipment to continuously excavate on the first side of the main power building, the side around the main power building, and the second side of the main power building, forming the first TBM excavation tunnel section, the second TBM excavation tunnel section, and the third TBM excavation tunnel section respectively; S2. Excavate the third TBM tunnel section on the second side of the main powerhouse using the drill-and-blast method to form a drill-and-blast tunnel section. The drill-and-blast tunnel section can connect to the end of the third TBM tunnel section away from the main powerhouse. S3. Receive and dismantle the TBM equipment at the intersection of the third TBM excavation tunnel section and the drill-and-blast tunnel section, and transport the TBM equipment back to the site through the drill-and-blast tunnel section. S4. The first and third TBM tunnel sections are excavated to permanent sections using the drill-and-blast method. The first TBM tunnel section is excavated to form a traffic tunnel into the plant, the second TBM tunnel section is excavated to form a drainage corridor, and the third TBM tunnel section is excavated in conjunction with the drill-and-blast section to form a ventilation and safety tunnel.

[0006] Through these technical approaches, TBM excavation is utilized as the primary construction method. The pilot tunnel created by the TBM excavation facilitates drill-and-blast excavation, which is then supplemented with drill-and-blast excavation. This improves mechanization, reduces reliance on manual labor, and reduces labor intensity. Furthermore, by combining continuous TBM excavation at one end with drill-and-blast excavation at the other, an efficient parallel operation mode is achieved, shortening the construction period of critical lines. The drill-and-blast tunnel section created by the drill-and-blast excavation also facilitates the transport and removal of the TBM equipment.

[0007] In some embodiments, the TBM excavation line formed by the first TBM excavation tunnel section, the second TBM excavation tunnel section, and the third TBM excavation tunnel section is arranged in a horizontal "W" shape on the plane.

[0008] In some embodiments, the TBM equipment located at the end of the first TBM excavation tunnel section excavates in a counterclockwise direction to connect with the head end of the second TBM excavation tunnel section, and the TBM equipment excavates in a clockwise direction around the main factory building to the other side of the main factory building. The TBM equipment located at the end of the second TBM excavation tunnel section excavates in a counterclockwise direction to connect with the head end of the third TBM excavation tunnel section.

[0009] In some embodiments, the turning radius of the second TBM excavation tunnel section is not less than 30m, and the distance from the second TBM excavation tunnel section is not less than 20m from the underground powerhouse cavern group.

[0010] In some embodiments, the temporary excavation sections of the first TBM excavation tunnel section, the second TBM excavation tunnel section, and the third TBM excavation tunnel section are all circular, with a slope of no more than 5% and a diameter of 3.53m.

[0011] In some embodiments, the permanent cross-section of the factory access tunnel is a city gate tunnel type with a size of 8.0m×8.3m.

[0012] In some embodiments, the permanent cross-section of the ventilation and safety tunnel is a city gate tunnel type with a size of 7.2m×7.0m.

[0013] The beneficial effects of the present invention are: 1. By introducing a combined construction method that uses TBM excavation as the primary method and drilling and blasting as a supplement, TBM equipment is first used to complete the excavation of multiple key tunnel sections without repeated visits to the site. This allows some of the TBM excavation tunnel sections to provide a pilot working surface for drilling and blasting expansion, which is then expanded and formed using drilling and blasting. Due to the high speed and strong continuity of TBM excavation, this coordination method can significantly shorten the construction period of key lines. While TBM excavation is being carried out on one side of the main powerhouse, drilling and blasting is used to excavate a section of the tunnel on the other side. On the one hand, simultaneous construction at both ends achieves parallel operations and improves construction efficiency. On the other hand, when the TBM excavation tunnel section is connected to the drilling and blasting tunnel section, the section of the tunnel excavated by drilling and blasting can be used as a rapid exit channel for the TBM equipment, eliminating the need to return along the original route and saving construction time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the planar structure of this application.

[0015] Figure 2 This is a schematic diagram of the cross-sectional structure of part of the tunnel section formed by TBM excavation in the factory access tunnel and ventilation and safety tunnel in this application.

[0016] Figure 3 It is a schematic diagram of the cross-sectional structure of the drainage corridor in this application.

[0017] Figure 4 It is a schematic diagram of the cross-sectional structure of a portion of a tunnel section formed by the drilling and blasting method in the ventilation and safety tunnel in this application.

[0018] Description of reference numerals: 1. Main powerhouse; 2. Access tunnel to the factory; 3. Drainage corridor; 4. Ventilation and safety tunnel; 5. First TBM tunnel section; 6. Second TBM tunnel section; 7. Third TBM tunnel section; 8. Drilling and blasting tunnel section.

[0019] This specification includes references to "one embodiment" or "an embodiment." The appearance of the phrase "in one embodiment" or "in an embodiment" does not necessarily refer to the same embodiment. The particular features, structures, or characteristics may be combined in any suitable manner consistent with the present disclosure.

[0020] The term "comprising" is open ended. As used in the appended claims, the term does not exclude additional structures or steps.

[0021] “First,” “second,” etc. As used herein, these terms act as labels for the nouns that precede them and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention are further described below with reference to specific embodiments.

[0023] Combine Figures 1 to 4 As shown, this embodiment is a method for excavating an underground factory entrance tunnel and a ventilation and safety tunnel, including the following steps: S1. Use TBM equipment to continuously excavate on the first side of the main power building 1, the side around the main power building 1, and the second side of the main power building 1, forming a first TBM excavation tunnel section 5, a second TBM excavation tunnel section 6, and a third TBM excavation tunnel section 7 respectively; S2. Excavate the third TBM tunnel section 7 on the second side of the main powerhouse 1 using the drill-and-blast method to form a drill-and-blast tunnel section 8. The drill-and-blast tunnel section 8 can connect to the end of the third TBM tunnel section 7 away from the main powerhouse 1. S3, receiving and disassembling the TBM equipment at the intersection of the third TBM excavation tunnel section 7 and the drill-blast tunnel section 8, and transporting the TBM equipment back to the site through the drill-blast tunnel section 8; S4. The first TBM tunnel section 5 and the third TBM tunnel section 7 are expanded to permanent sections using the drill-and-blast method, so that the first TBM tunnel section 5 is expanded to form a traffic tunnel into the factory, the second TBM tunnel section 6 forms a drainage corridor 3, and the third TBM tunnel section 7 is expanded and cooperated with the drill-and-blast section 8 to form a ventilation and safety tunnel.

[0024] In some embodiments, step S0 is also included, in which the TBM equipment is first transported to the entrance 2 of the factory traffic tunnel for assembly.

[0025] Furthermore, after the TBM equipment in this embodiment is assembled, it is excavated downhill along the axis of the access tunnel to the downstream drainage corridor 3. The TBM at the end of the first TBM tunnel section 5 excavates counterclockwise to the downstream drainage corridor 3 to connect with the beginning of the second TBM tunnel section 6. The TBM then excavates clockwise around the main powerhouse 1 and ascends the slope to the other side of the main powerhouse 1. The TBM at the end of the second TBM tunnel section 6 excavates counterclockwise to the ventilation and safety tunnel to connect with the beginning of the third TBM tunnel section 7. After reaching the end of the ventilation and safety tunnel, excavation is continued along the axis of the ventilation and safety tunnel toward the ventilation and safety tunnel entrance 4.

[0026] Furthermore, in this embodiment, the turning radius of the second TBM excavation tunnel section 6 is not less than 30m, and the distance from the underground powerhouse cavern group is not less than 20m.

[0027] Furthermore, in this embodiment, the temporary excavation cross-sections for the first TBM tunnel section 5, the second TBM tunnel section 6, and the third TBM tunnel section 7 are all circular, with a TBM excavation slope of less than 5% and a diameter of 3.53 meters. Specifically, due to limitations of the TBM equipment, the TBM excavation slope must be controlled within 5%. When excavating in a straight line from the access tunnel to the ventilation and safety tunnel, an excavation slope greater than 5% would make excavation difficult. Therefore, in this embodiment, the TBM excavation route formed by the continuous first TBM tunnel section 5, the second TBM tunnel section 6, and the third TBM tunnel section 7 forms a horizontal "W" shape in plan. By excavating along the excavation route from the end of the ventilation and safety tunnel to the downstream exhaust corridor and then to the end of the access tunnel, while maintaining the excavation slope within 5%, the downstream drainage corridor can also be indirectly excavated. In some embodiments, in step S2, while the TBM is excavating, the conventional drilling and blasting method is used to excavate from the ventilation and safety tunnel entrance 4 into the tunnel, and intersect and penetrate with the middle part of the ventilation and safety tunnel. The TBM equipment is then received and disassembled at this location, and finally transported to the ventilation and safety tunnel entrance 4 and then withdrawn.

[0028] In some implementation schemes, the permanent cross-section of the entire factory access tunnel in this embodiment is a city gate tunnel type with a size of 8.0m×8.3m.

[0029] In some embodiments, the permanent cross-section of the ventilation and safety tunnel in this embodiment is a city gate tunnel type with a size of 7.2m×7.0m.

[0030] The implementation principle of a method for excavating an underground factory entrance traffic tunnel and a ventilation and safety tunnel is as follows: By combining TBM and drilling and blasting methods, the excavation of the underground powerhouse access tunnel and ventilation and safety tunnel has significantly improved the level of construction mechanization. With TBM as the main method and drilling and blasting as the auxiliary method, the reliance on manual labor and labor intensity have been reduced, the safety risks of underground engineering construction have been reduced, the construction progress of the access tunnel and ventilation and safety tunnel has been accelerated, and the project power generation period has been shortened.

[0031] By continuously excavating three sections of the TBM, the equipment was able to complete the excavation of the access tunnel, drainage corridor 3, and part of the ventilation and safety tunnel without repeated visits, thus improving equipment utilization. The drill-and-blast method was used to construct the ventilation and safety tunnel from the entrance 4 toward the center, providing a quick exit for the TBM equipment and eliminating the need to retract the TBM along its original route, thus improving construction efficiency. Because the TBM can achieve rapid and continuous excavation, it can open up key lines in advance. The tunnel section formed by the TBM excavation is not the final structural end section, but rather a preliminary tunnel section, which can provide a working surface for subsequent drilling and blasting, saving the time of excavating a separate pilot tunnel for drilling and blasting. The pilot tunnel first reveals the geological conditions, providing a safe environment for expansion excavation, and finally, the expansion and completion are completed through drilling and blasting.

[0032] The above are all preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for excavating an underground factory entrance tunnel and a ventilation and safety tunnel, characterized in that: The steps include: S1, using TBM equipment to continuously excavate on the first side of the main power building (1), the side around the main power building (1) and the second side of the main power building (1), respectively forming a first TBM excavation tunnel section (5), a second TBM excavation tunnel section (6) and a third TBM excavation tunnel section (7); S2, using the drill-and-blast method to excavate the third TBM tunnel section (7) on the second side of the main powerhouse (1) to form a drill-and-blast tunnel section (8), wherein the drill-and-blast tunnel section (8) can be connected to the end of the third TBM tunnel section (7) away from the main powerhouse (1); S3, receiving and disassembling the TBM equipment at the intersection of the third TBM excavation tunnel section (7) and the drill-blast tunnel section (8), and transporting the TBM equipment back to the site through the drill-blast tunnel section (8); S4. The first TBM tunnel section (5) and the third TBM tunnel section (7) are excavated to a permanent section by drilling and blasting, so that the first TBM tunnel section (5) is excavated to form a traffic tunnel for entering the plant, the second TBM tunnel section (6) forms a drainage corridor (3), and the third TBM tunnel section (7) is excavated in conjunction with the drilling and blasting tunnel section (8) to form a ventilation and safety tunnel.

2. The method for excavating an underground factory entrance tunnel and a ventilation and safety tunnel according to claim 1, characterized in that: The TBM excavation line formed by the first TBM excavation tunnel section (5), the second TBM excavation tunnel section (6), and the third TBM excavation tunnel section (7) being connected as a whole is arranged in a horizontal "W" shape on the plane.

3. The method for excavating an underground factory entrance tunnel and a ventilation and safety tunnel according to claim 1, characterized in that: The TBM equipment located at the end of the first TBM excavation tunnel section (5) excavates in a counterclockwise direction to connect with the head end of the second TBM excavation tunnel section (6), and the TBM equipment excavates in a clockwise direction around the main powerhouse (1) until it reaches the other side of the main powerhouse (1). The TBM equipment located at the end of the second TBM excavation tunnel section (6) excavates in a counterclockwise direction to connect with the head end of the third TBM excavation tunnel section (7).

4. The method for excavating an underground factory entrance tunnel and a ventilation and safety tunnel according to claim 3, characterized in that: The turning radius of the second TBM excavation tunnel section (6) is not less than 30m, and the distance from the underground powerhouse cavern group is not less than 20m.

5. The method for excavating an underground factory entrance tunnel and a ventilation and safety tunnel according to claim 1, characterized in that: The temporary excavation sections of the first TBM excavation tunnel section (5), the second TBM excavation tunnel section (6), and the third TBM excavation tunnel section (7) are all circular, with a slope of no more than 5% and a diameter of 3.53m.

6. The method for excavating an underground factory entrance tunnel and a ventilation and safety tunnel according to claim 1, characterized in that: The permanent cross-section of the factory access tunnel is a city gate tunnel type with dimensions of 8.0m×8.3m.

7. The method for excavating an underground factory entrance tunnel and a ventilation and safety tunnel according to claim 1, characterized in that: The permanent cross-section of the ventilation and safety tunnel is a city gate tunnel type with a size of 7.2m×7.0m.

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