An overall launching method of an ultra-buried deep large-diameter EPB-TBM double-mode shield

Abstract

The application provides an EPB-TBM double-mode shield whole launching method for super deep and large diameter, and relates to the technical field of shield tunnel construction.The method comprises the following steps: excavating and supporting a vertical shaft, a pilot tunnel and a rear blind hole in sequence to form a mutual communication; installing a launching base and a rear steel frame in the vertical shaft, hoisting the main machine components of a shield machine into the vertical shaft and assembling the main machine components on the launching base; pushing the assembled main machine components forward in the pilot tunnel and synchronously assembling multiple trolleys used in sequence in the rear; pouring a counterforce ring beam in the tunnel face area of the pilot tunnel, and installing a continuous slag removal system in the composite space formed by the vertical shaft, the pilot tunnel and the rear blind hole; starting the shield machine to perform whole launching and excavation when the counterforce ring beam reaches the first design strength, and continuously removing slag through the continuous slag removal system.The method not only greatly shortens the shield launching time, saves the large-area foundation pit excavation link and significantly saves the construction cost, but also improves the construction efficiency of super deep and large diameter tunnels.

Description

Technical Field

[0001] This invention generally relates to the field of shield tunnel construction technology, and specifically to an integral launching method for a large-diameter EPB-TBM dual-mode shield tunneling machine with ultra-deep burial depth. Background Technology

[0002] With the increasing number of large-diameter tunnels being built for intercity railways and urban highways, tunnel engineering is gradually developing towards larger, deeper tunnels with more complex geological conditions, and ultra-large diameter shield tunnels are now widely used. Among them, the EPB-TBM dual-mode shield tunneling machine is widely used in ultra-deep large-diameter shield tunnels because it can switch freely between hard rock and soft soil strata.

[0003] For typical subway tunnels, the subway station foundation pit is usually constructed first, and then the tunnel boring machine (TBM) is launched from the station foundation pit. However, for intercity railway or urban highway tunnels, due to the long route length and limited number of stations, some sections cannot be launched from the station foundation pit. Instead, vertical shafts must be excavated to assist in the TBM launch. The inherently small opening area of ​​such launch shafts makes the underground assembly and launch operations of ultra-deep, large-diameter EPB-TBM dual-mode TBMs difficult and time-consuming. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the existing technology, it is desirable to provide an integral launching method for ultra-deep, large-diameter EPB-TBM dual-mode shield tunneling machines that improves launching efficiency and reliability.

[0005] This invention provides a method for the overall launching of a dual-mode shield tunneling machine with ultra-deep, large-diameter EPB-TBM, comprising the following steps:

[0006] The excavation and support were carried out in sequence to form interconnected vertical shafts, pilot tunnels, and rear blind tunnels;

[0007] The launching base and rear steel frame are installed inside the vertical shaft, and the main components of the tunnel boring machine are hoisted into the vertical shaft and assembled onto the launching base.

[0008] The assembled shield machine main unit is pushed in the pilot tunnel in a direction away from the rear blind tunnel, and multiple matching trolleys are assembled in sequence on the side of the shield machine main unit close to the rear blind tunnel.

[0009] A reaction ring beam is cast in the working face area of ​​the pilot tunnel, and a continuous slag discharge system is installed in the composite space formed by the vertical shaft, the pilot tunnel, and the rear blind tunnel.

[0010] Once the reaction ring beam reaches the first design strength, the tunnel boring machine is started for overall excavation and excavation, and the continuous slag discharge system is used for continuous slag removal.

[0011] According to the technical solution provided by the present invention, the interconnected vertical shaft, the pilot tunnel, and the rear blind tunnel are excavated and supported sequentially, specifically including the following steps:

[0012] The vertical shaft was excavated layer by layer, and the ring beam was constructed along with the excavation.

[0013] Simultaneously excavate the pilot tunnel and the rear blind tunnel, and implement initial support;

[0014] A launching platform was constructed in the leading tunnel, and the invert arch and backfill concrete of the rear blind tunnel were poured.

[0015] According to the technical solution provided by the present invention, the spacing between two adjacent ring beams is 8 to 10 meters; a reaction ring beam groove is provided in the front guide tunnel; the bottom elevation of the rear blind tunnel is 50 cm higher than the bottom elevation of the front guide tunnel.

[0016] According to the technical solution provided by the present invention, the ring beam near the bottom of the shaft is flush with the top of the inverted arch of the rear blind tunnel; the top surface of the launching base is flush with the top surface of the launching guide platform.

[0017] According to the technical solution provided by the present invention, the main components of the tunnel boring machine include at least the shield body, the cutterhead, and the screw conveyor;

[0018] The process of hoisting the main components of the tunnel boring machine into the shaft includes the following steps:

[0019] Once the launching base reaches the second design strength, the shield, the cutterhead, and the screw conveyor are sequentially hoisted into the vertical shaft.

[0020] According to the technical solution provided by the present invention, the method further includes the following steps:

[0021] During the process of the tunnel boring machine main unit moving forward in the pilot tunnel, at least three segments are simultaneously assembled at the bottom of the pilot tunnel and grout is injected behind the shield wall into the gap at the shield tail outside the segments to form a grout body behind the shield wall.

[0022] A central box culvert is installed within the annular space of the grouting body behind the shield wall.

[0023] According to the technical solution provided by the present invention, a concave groove is provided at the middle position of the launching guide platform, and the radius of curvature of the concave groove is equal to the outer radius of curvature of the tube segment; the bottom of the central box culvert is arc-shaped, and the radius of curvature of the central box culvert is equal to the inner radius of curvature of the tube segment.

[0024] According to the technical solution provided by the present invention, the supporting force provided by the reaction ring beam is greater than the water and soil pressure in front of the tunnel boring machine at the start of the tunnel boring machine; the inner side of the reaction ring beam is flush with the inner side of the assembled tunnel segment.

[0025] According to the technical solution provided by the present invention, the continuous slag discharge system includes:

[0026] The horizontal continuous belt conveyor and the vertical belt conveyor are used in conjunction. The horizontal continuous belt conveyor is installed in the pilot tunnel and the rear blind tunnel, and the vertical belt conveyor is installed in the vertical shaft. The horizontal continuous belt conveyor is used to transport the excavated soil generated during the overall initial excavation of the tunnel boring machine to the vertical belt conveyor, and the vertical belt conveyor is used to lift the excavated soil to the ground.

[0027] According to the technical solution provided by the present invention, taking the reaction ring beam as the boundary, the cross-section of the guide tunnel near the vertical shaft is horseshoe-shaped, and the cross-section of the guide tunnel near the working face is circular, and the central axis of the horseshoe-shaped cross-section coincides with the central axis of the circular cross-section.

[0028] As can be seen from the above technical solution, the present invention has at least the following beneficial effects:

[0029] This invention provides a method for the overall launching of a dual-mode shield tunneling machine (EPB-TBM) with ultra-deep, large-diameter structure, comprising the following steps: sequentially excavating and supporting an interconnected vertical shaft, a pilot tunnel, and a rear blind tunnel; installing a launching base and a rear steel frame within the vertical shaft, hoisting the main shield machine components into the vertical shaft, and assembling them onto the launching base; moving the assembled main shield machine components in the pilot tunnel away from the rear blind tunnel, while simultaneously assembling multiple matching trolleys sequentially on the side of the main shield machine components near the rear blind tunnel; casting a reaction ring beam in the working face area of ​​the pilot tunnel, and installing a continuous muck removal system within the composite space formed by the vertical shaft, pilot tunnel, and rear blind tunnel; and starting the shield machine for overall excavation and continuously removing muck through the continuous muck removal system after the reaction ring beam reaches its first design strength.

[0030] This invention creates an interconnected vertical shaft, pilot tunnel, and rear blind tunnel through excavation and support, providing ample space for the launch of the tunnel boring machine (TBM). This solves the problem that narrow vertical shafts cannot accommodate the assembly and launch of large-diameter TBMs. By installing a launching base and a rear steel frame within the vertical shaft to stably support the TBM's main components, the TBM's main components are hoisted down into the shaft for assembly and then pushed forward in the pilot tunnel. Simultaneously, the supporting trolleys are assembled sequentially at the rear. This reduces frequent hoisting operations in confined spaces, lowers the risk of equipment collision damage, and avoids shield... This invention eliminates the cumbersome process of multiple assembly and debugging of the tunnel boring machine (TBM). It further reduces the time required for TBM launch, eliminates the need for large-area foundation pit excavation, significantly saves construction costs, and fully utilizes the optimal performance of the TBM, improving the construction efficiency of ultra-deep, large-diameter tunnels. By casting a reaction ring beam at the tunnel face in the pilot tunnel to meet the required support strength, stable support is provided for the TBM's excavation. Combined with a continuous muck removal system installed in the composite space, the invention enables the TBM to begin overall excavation and continuously remove muck after the reaction ring beam reaches its first design strength. Attached Figure Description

[0031] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0032] Figure 1 A flowchart of the overall launching method for ultra-deep, large-diameter EPB-TBM dual-mode shield tunneling.

[0033] Figure 2 This is a schematic diagram after the shaft has been excavated.

[0034] Figure 3 A schematic diagram showing the completion of the lead tunnel and the rear blind tunnel.

[0035] Figure 4 This is a schematic diagram showing the shield, cutterhead, and screw conveyor after they have been hoisted and lowered into the well.

[0036] Figure 5 This is a schematic diagram showing the No. 1 and No. 2 trolleys after they have been hoisted and lowered into the well.

[0037] Figure 6 This is a schematic diagram of the tunnel boring machine after it has been pushed to the working face.

[0038] Figure 7 This is a schematic diagram showing the installation of a horizontal continuous belt conveyor and a vertical belt conveyor.

[0039] Figure 8 This is a three-dimensional view of the reaction ring beam in the pilot tunnel.

[0040] Figure 9 This is a cross-sectional view of the reaction ring beam in the pilot tunnel.

[0041] Figure 10This is a schematic diagram of the lead tunnel, vertical shaft, and rear blind tunnel.

[0042] Figure 11 for Figure 10 A schematic diagram of section AA.

[0043] Figure 12 for Figure 10 A schematic diagram of the BB section.

[0044] Numbered in the diagram: 1. Stratum; 2. Shaft; 3. Rear blind tunnel; 4. Forward tunnel; 5. Rear steel frame; 6. Launching base; 7. Cutterhead; 8. Screw conveyor; 9. Shield body; 10. No. 1 trolley; 11. No. 2 trolley; 12. No. 3 trolley; 13. No. 4 trolley; 14. Horizontal continuous belt conveyor; 15. Vertical belt conveyor; 16. Initial support; 17. Grouting body behind the shield wall; 18. Segment; 19. Reaction ring beam; 20. Secondary lining; 21. Launching guide platform; 22. Central box culvert; 23. Tensioning device. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] like Figure 1 As shown, this invention provides a method for the overall launching of a dual-mode shield tunneling machine with a large diameter EPB-TBM at ultra-deep burial depth, comprising the following steps:

[0048] S100, excavate and support in sequence to form interconnected vertical shaft 2, pilot tunnel 4 and rear blind tunnel 3.

[0049] The purpose of this step is to create basic space for the assembly, forward movement, and launch of the ultra-deep, large-diameter EPB-TBM dual-mode tunnel boring machine, solving the problem that traditional narrow shafts cannot meet the launch space requirements of large-diameter tunnel boring machines. Here, the interconnected shaft 2, pilot tunnel 4, and rear blind tunnel 3 are excavated and supported sequentially, specifically including the following steps:

[0050] The vertical shaft 2 is excavated layer by layer, and the ring beam is constructed along with the excavation; the pilot tunnel 4 and the rear blind tunnel 3 are excavated simultaneously, and the initial support 16 is constructed; the starting platform 21 is constructed in the pilot tunnel 4, and the invert arch of the rear blind tunnel 3 is poured and backfilled with concrete.

[0051] It should be noted that, as Figure 2As shown, a vertical passage, namely shaft 2, is excavated layer by layer in the ultra-deep stratum 1 to meet the hoisting requirements of the main components of the tunnel boring machine. Simultaneously with the excavation progress, a ring beam is constructed to constrain the deformation of the surrounding rock of shaft 2, disperse the pressure of the surrounding stratum, and prevent the shaft wall of shaft 2 from converging or collapsing. The ring beam can be formed by casting high-strength concrete.

[0052] like Figure 3 As shown, the pilot tunnel 4 and the rear blind tunnel 3, which are connected to the vertical shaft 2, are excavated simultaneously. The pilot tunnel 4 is used for the forward movement of the main components of the tunnel boring machine and for face excavation, while the rear blind tunnel 3 is used for the installation of a continuous muck removal system and the storage of subsequent auxiliary equipment. The simultaneous excavation of both can shorten the construction period to some extent. Furthermore, after excavation for a period of time, initial support 16 is constructed to prevent the surrounding rock from weathering, spalling, or collapsing due to prolonged exposure. Here, the initial support 16 is, for example, shotcrete and anchor support, which uses shotcrete and anchor bolts for fixation.

[0053] The starting guide platform 21 provides guidance for the forward movement of the main components of the tunnel boring machine, while the invert arch and backfill concrete of the blind tunnel 3 after pouring provide a stable installation foundation for the continuous slag removal system and subsequent supporting equipment.

[0054] Furthermore, the spacing between two adjacent ring beams is, for example, 8 to 10 meters. This avoids the problem of too small a spacing leading to frequent construction procedures and increased construction costs and time for the ring beams, while also preventing the problem of too large a spacing causing the vertical shaft wall to converge and collapse in deep strata.

[0055] A reaction ring beam groove is installed inside the pilot tunnel 4 for subsequent casting of the reaction ring beam 19. This provides stable reaction force support for the overall initial excavation of the tunnel boring machine (TBM), solving the problem of insufficient support and easy retreat of the TBM during excavation in ultra-deep strata. It also avoids secondary excavation of the surrounding rock of the intact pilot tunnel, reducing disturbance to the pilot tunnel structure. Here, the reaction ring beam groove can be located at the first quarter of the length of the pilot tunnel 4, measured from its opening. This location matches the stopping position of the TBM after it has been pushed to the working face, ensuring that the reaction ring beam 19 can directly fit against the tail of the TBM after casting, efficiently transferring support force.

[0056] The bottom elevation of the rear blind tunnel 3 is higher than that of the front tunnel 4 by, for example, 50cm. This ensures the normal operation of the continuous slag discharge system and supporting equipment in the rear blind tunnel, and also prevents water and slag from flowing into the rear blind tunnel 3 from the front tunnel 4, thus avoiding equipment failure or blockage of the slag discharge channel.

[0057] In addition, due to the fact that in the ultra-deep strata, the vertical shaft 2 bears the vertical stratum pressure and the rear blind tunnel 3 bears the horizontal surrounding rock pressure, the connection between the two is prone to stress concentration due to the different directions of force. The ring beam near the bottom of the vertical shaft 2 is flush with the top of the inverted arch of the rear blind tunnel 3, which allows the ring beam to bear part of the horizontal pressure at the same time, and to evenly transfer the stress to the stratum 1 around the vertical shaft 2, preventing the shaft wall or the top of the inverted arch of the rear blind tunnel 3 from cracking or collapsing due to excessive local stress.

[0058] S200. Install the launching base 6 and the rear steel frame 5 inside the shaft 2, and hoist the main components of the tunnel boring machine into the shaft 2 and assemble them on the launching base 6.

[0059] The launching base 6 is fixed to the bottom of the shaft 2, serving as a platform for the installation and fine-tuning of the main components of the tunnel boring machine (TBM). The rear steel frame 5 is installed on the side wall of the shaft 2 behind the launching base 6, providing reverse thrust during the air-pushing of the TBM main components and serving as the initial support and anchoring point for subsequent auxiliary equipment during the trolley assembly stage. The launching base 6 and the rear steel frame 5 together constitute the basic support system for underground launching, ensuring the stability and safety of the main assembly, air-pushing, and launching processes.

[0060] like Figure 4 As shown, the main components of the tunnel boring machine (TBM) include at least the shield body 9, the cutterhead 7, and the screw conveyor 8. The shield body 9, as the main protective structure of the TBM, has a shape that matches the tunnel cross-section. During excavation, it can support the water and soil pressure of the ultra-deep strata 1, preventing the collapse of the tunnel face and surrounding rock. Simultaneously, the interior of the shield body 9 provides installation and operating space for components such as the cutterhead 7 and the screw conveyor 8, ensuring that each core device operates in a closed and stable environment, preventing rock debris and seepage water from directly intruding into the equipment and causing malfunctions. The cutterhead 7, as the ground cutting execution unit of the TBM, is equipped with high-strength cutting tools on its edges. It can switch working modes according to the hardness or softness of the ultra-deep strata, operating in either TBM mode or EPB mode. For example, in hard rock strata, it uses rotational cutting to break the rock; in soft soil strata, it uses mixing blades to create earth pressure balance with the excavated soil inside the chamber, preventing water inrush and collapse at the tunnel face. The screw conveyor 8 serves as the core channel for transporting excavated soil in the tunnel boring machine. One end of the screw conveyor 8 is connected to the excavated soil chamber inside the shield body 9, and the other end extends to the subsequent continuous slag discharge system. It can continuously transport the excavated soil generated by the cutterhead 7 out of the shield body 9. In EPB mode, the screw conveyor 8 can also control the amount of excavated soil discharged by adjusting its speed. In conjunction with the pressure inside the shield body 9 chamber, it can maintain the earth pressure balance at the tunnel face and prevent soil inrush and settlement in soft soil strata at excessive burial depth due to pressure imbalance.

[0061] Here, as Figure 5 As shown, the main components of the tunnel boring machine are hoisted into shaft 2, specifically including the following steps:

[0062] Once the launching base 6 reaches the second design strength, the shield body 9, cutterhead 7, and screw conveyor 8 will be hoisted into the vertical shaft 2 in sequence.

[0063] It should be noted that during ultra-deep burial construction, the ground pressure around shaft 2 is high. If the starting base 6 deforms due to insufficient strength, it will not only damage the equipment but may also cause instability of the shaft wall, resulting in a safety accident. Only after confirming that the strength of the starting base 6 meets the standard can the hoisting stage be carried out to ensure the safety and stability of subsequent operations; here, the second design strength is, for example, 30MPa.

[0064] First, hoist the shield body 9. After it is lowered into the shaft, it needs to be precisely positioned and fixed on the launching base 6. Subsequently, the cutterhead 7 needs to be installed on one side of the cutting surface of the shield body 9, and the screw conveyor 8 needs to penetrate through the middle compartment of the shield body 9. If other components are hoisted first, they will be unable to be installed because the shield body 9 is not in place, and they will also occupy the limited space in the shaft 2, affecting subsequent hoisting operations.

[0065] Furthermore, the top surface of the launching base 6 is designed to be flush with the top surface of the launching guide platform 21. The purpose of this design is to provide a smooth forward movement trajectory for the main components of the tunnel boring machine (TBM), solve the problem of jamming and deviation caused by the elevation difference when the TBM enters the pilot tunnel 4 from the vertical shaft 2, and ensure that the main components of the TBM can move forward stably along a unified axis, thus laying a precise positional foundation for the subsequent overall excavation.

[0066] S300: The assembled shield machine main unit is pushed in the pilot tunnel 4 in a direction away from the rear blind tunnel 3, and multiple matching trolleys are assembled in sequence on the side of the shield machine main unit close to the rear blind tunnel 3.

[0067] like Figure 6 As shown, step S300 mainly involves the assembly of the main components of the tunnel boring machine (TBM), followed by its forward movement along the starting platform 21 inside the pilot tunnel 4. "Remote movement" refers to movement without any tunneling operations, relying solely on the equipment's own power or auxiliary devices. During this forward movement, the supporting trolleys must be hoisted and assembled sequentially from behind in the order of trolley number 10, trolley number 11, trolley number 12, and trolley number 13. The trolley assembly must match the progress of the main machine's forward movement to ensure smooth connection. Simultaneously, at least three segments 18 and the central box culvert 22 at the bottom of the pilot tunnel 4 must be assembled concurrently during the forward movement. The assembly of the segments 18 and the central box culvert 22 provides temporary support for the TBM's forward movement and lays the foundation for subsequent tunnel structure formation, preventing disturbance of the surrounding rock in the pilot tunnel caused by the forward movement of the main machine.

[0068] This method also includes the following steps:

[0069] During the process of the main component of the tunnel boring machine moving forward in the pilot tunnel 4, at least three segments 18 are simultaneously assembled at the bottom of the pilot tunnel 4 and grouting is performed behind the shield wall in the shield tail gap outside the segments 18 to form a grouting body 17 behind the shield wall.

[0070] A central box culvert 22 is installed within the annular space of the grouting body 17 behind the shield wall.

[0071] It should be noted that segment 18 is used to bear the weight of the tunnel boring machine and transmit ground pressure; there are at least three segments 18. During the assembly process, the position of the segments must be calibrated by a laser positioning instrument to ensure that the joints of adjacent segments are flat, so as to ensure that the support is evenly stressed and to avoid cracking of a single segment 18 due to concentrated load.

[0072] After the segment 18 is assembled, grout is injected into the shield tail gap on the outside of segment 18, that is, the gap between the outer side of segment 18 and the surrounding rock / initial support 16 of the pilot tunnel. This gap is the space that is naturally formed between segment 18 and the surrounding rock after the shield body 9 of the tunnel boring machine moves forward. If it is not filled, the surrounding rock may shrink into the gap, causing surface or stratum subsidence. The injected grout can be a cement-water glass dual-liquid grout to ensure rapid solidification after grouting to form the grout body 17 behind the shield wall, avoiding grout loss. The grout body 17 behind the shield wall must fill the entire shield tail gap, and the 24-hour strength must meet the design requirements, such as not less than 5MPa. This not only fills the gap but also helps segment 18 withstand the pressure on the stratum 1 side, enhancing the support stability of segment 18.

[0073] After the grouting body 17 behind the shield wall reaches the design requirements, the central box culvert 22 is installed. The bottom of the central box culvert 22 is designed to be arc-shaped, and its radius of curvature must be exactly equal to the radius of the inner side of the segment 18 to ensure that the bottom of the central box culvert 22 fits tightly with the inner side of the segment 18, avoiding uneven stress on the central box culvert 22 due to gaps. At the same time, the length of the central box culvert 22 must match the length of the segment 18 assembly section to facilitate segment-by-segment installation and connection. Specifically, during installation, the inner axis of the segment 18 is used as a reference, and the elevation and horizontal position of the central box culvert 22 are calibrated using a level and total station to ensure that the axis of the central box culvert 22 coincides with the axis of the pilot tunnel 4. The joints between the central box culverts 22 can be treated with rubber waterstop strips to prevent water seepage into the interior of the central box culvert 22 during tunnel operation, which could affect the operation of equipment or pipelines.

[0074] Furthermore, a concave groove is provided in the middle of the launching guide platform 21. The radius of curvature of the concave groove is equal to the radius of curvature of the outer side of the segment 18, ensuring that the segment 18 can fit tightly with the launching guide platform 21 after assembly. At the same time, when the shield body 9 of the tunnel boring machine moves forward along the concave groove, the trajectory is completely coincident with the tunnel design axis, avoiding horizontal or vertical deviation. Meanwhile, the fitting support surface can evenly transfer the ground pressure and the weight of the tunnel boring machine borne by the segment 18 to the launching guide platform 21, preventing the segment 18 from cracking due to excessive local stress and ensuring the safety of the temporary tunnel structure.

[0075] The bottom of the central box culvert 22 is arc-shaped, and the radius of curvature of the central box culvert 22 is equal to the inner radius of curvature of the segment 18. This ensures that after the central box culvert 22 is installed, its bottom fits seamlessly with the inner side of the segment 18 without any obvious gaps. This avoids point contact caused by gaps when the box culvert is under stress, which could lead to local stress concentration.

[0076] Furthermore, based on the installation and positioning of the grouting body 17 behind the shield wall and the central box culvert 22, a secondary lining, namely the secondary lining 20, is constructed inside the pilot tunnel 4. The secondary lining 20 is the load-bearing and waterproof structure of the tunnel, and is cast within a composite support system formed by the segments 18, the grouting body 17 behind the shield wall, and the initial support 16. The secondary lining 20 provides a reliable channel with high strength and good stability for the subsequent overall launch of the tunnel boring machine.

[0077] S400, cast the reaction ring beam 19 in the working face area of ​​the pilot tunnel 4, and install a continuous slag discharge system in the composite space formed by the vertical shaft 2, the pilot tunnel 4 and the rear blind tunnel 3.

[0078] like Figure 8 and Figure 9 As shown, after the main shield machine component is pushed to the face of the pilot tunnel 4, concrete is poured into the pre-set reaction ring beam groove to form the reaction ring beam 19. The supporting force provided by the reaction ring beam 19 must be greater than the water and soil pressure in front of the shield machine at the start of the tunnel, in order to prevent the shield machine from retreating due to excessive pressure in front during tunneling. In addition, the inner side of the reaction ring beam 19 is flush with the inner side of the segment 18 to ensure the smoothness of the tunnel structure and avoid jamming during subsequent tunneling.

[0079] like Figure 7 and Figure 10As shown, horizontal continuous belt conveyors 14 are installed in the pilot tunnel 4 and the rear blind tunnel 3. The tensioning device 23 of the horizontal continuous belt conveyor 14 is located in the rear blind tunnel 3 to facilitate adjustment of the belt tension. Simultaneously, a vertical belt conveyor 15 is installed in the shaft 2, and the two are connected to form a continuous muck discharge channel. The horizontal continuous belt conveyor 14 is used to transport the muck generated during the initial excavation of the tunnel boring machine to the vertical belt conveyor 15, which in turn lifts the muck to the surface. Specifically, during the initial excavation of the tunnel boring machine (TBM), the excavated soil generated by the cutterhead 7 cutting the strata at the tunnel face is collected in the excavated soil bin inside the shield body 9 and discharged at a stable rate by the screw conveyor 8 to the feed end of the horizontal continuous belt conveyor 14 inside the pilot tunnel 4. The horizontal continuous belt conveyor 14 operates at a constant speed, transporting the excavated soil from the tail of the TBM (the area of ​​the pilot tunnel 4) along the axis to the area of ​​the rear blind tunnel 3. During this process, the tension of the belt is adjusted by the tensioning device 23 to ensure that the excavated soil does not slip or accumulate. After the excavated soil reaches the junction of the rear blind tunnel 3 and the vertical shaft 2, it enters the feed end of the vertical belt conveyor 15 through the transition chute. The vertical belt conveyor lifts the excavated soil along the vertical shaft 2 to the ground, and finally it is transported by ground excavated soil trucks to the designated disposal site, ensuring that the excavated soil is transported without any omissions or blockages. Here, the tensioning device 23 can be, for example, a counterweight tensioning structure or a screw tensioning structure, such as using a jack.

[0080] In addition, such as Figure 11 and Figure 12 As shown, with the reaction ring beam 19 as the boundary, the cross-section of the pilot tunnel 4 near the vertical shaft 2 is horseshoe-shaped, while the cross-section near the working face is circular, and the central axis of the horseshoe-shaped cross-section coincides with the central axis of the circular cross-section. The horseshoe-shaped cross-section is used to adapt to the working space of multiple processes, avoiding interference between processes due to narrow space. The circular cross-section is used to adapt to the initial excavation space of the tunnel boring machine, which facilitates subsequent grouting and filling behind the wall, and avoids shield jamming and local collapse due to excessive stress on the surrounding rock caused by mismatch in cross-section shape; at the same time, the circular cross-section matches the circular structure of the segment 18, laying the foundation for the formation of the permanent tunnel structure after the segment 18 is assembled. The coincidence of the central axis of the horseshoe-shaped cross-section and the central axis of the circular cross-section forms a smooth connection, making the stress at the transition uniform and ensuring that the overall structure of the pilot tunnel 4 is safer and more reliable.

[0081] S500: Once the reaction ring beam 19 reaches the first design strength, the tunnel boring machine is started for overall excavation and continuous slag removal through the continuous slag removal system.

[0082] The first design strength is, for example, 60 MPa, to ensure that the concrete of the reaction ring beam 19 is cured to the point that it can withstand the reaction force of the tunnel boring machine, and to prevent the reaction ring beam 19 from cracking and causing support failure.

[0083] Furthermore, after the reaction ring beam 19 reaches its first design strength, the tunnel boring machine (TBM) needs to be debugged and its launching conditions checked. This mainly includes debugging the hydraulic system, assembly system, thrust system, foam system, and operating system one by one to ensure that each system is operating normally. The launching conditions include at least whether the tunnel face is stable, whether the recoil force is sufficient, and whether the cutterhead rotates normally. If the debugging is completed and the launching conditions are all normal, the TBM will be started for construction. Here, after the TBM is started, an integrated launching and excavation mode is adopted, that is, the main machine and the supporting trolley excavate synchronously, without the need for separate assembly and debugging. The excavated soil generated during the excavation process is discharged and transported off-site through a continuous muck removal system to ensure excavation efficiency and avoid muck accumulation affecting the construction progress, ultimately achieving efficient and safe launching of ultra-deep large-diameter tunnels.

[0084] This invention creates a sufficient composite space for the launch of a tunnel boring machine (TBM) by excavating and supporting interconnected vertical shafts 2, a pilot tunnel 4, and a rear blind tunnel 3, thus solving the problem that the narrow vertical shaft 2 cannot meet the assembly and launch requirements of large-diameter TBMs. By installing a launch base 6 and a rear steel frame 5 within the vertical shaft 2 to stably support the main TBM components, the main TBM components, after being hoisted down into the shaft for assembly, are then pushed forward in the pilot tunnel 4, while simultaneously assembling the supporting trolleys at the rear. This reduces frequent hoisting operations in the confined space, lowers the risk of equipment collision damage, and avoids shield... The invention eliminates the cumbersome process of multiple assembly and debugging of the tunnel boring machine (TBM). Furthermore, by casting a reaction ring beam 19 at the face of the pilot tunnel 4 to meet the required support force, stable support is provided for the TBM's excavation. Combined with a continuous muck removal system installed in the composite space, the TBM can achieve overall initial excavation and continuous muck removal after the reaction ring beam 19 reaches its first design strength. This invention not only significantly shortens the TBM's launch time and eliminates the need for large-area foundation pit excavation, thus significantly saving construction costs, but also fully utilizes the optimal performance of the TBM, improving the construction efficiency of ultra-deep, large-diameter tunnels.

[0085] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A method for the overall launching of a dual-mode shield tunneling machine (EPB-TBM) with ultra-deep burial and large diameter, characterized in that, Includes the following steps: The interconnected vertical shafts (2), the pilot tunnel (4), and the rear blind tunnel (3) were excavated and supported in sequence. The launching base (6) and the rear steel frame (5) are installed in the shaft (2), and the main components of the tunnel boring machine are hoisted into the shaft (2) and assembled on the launching base (6); The assembled shield machine main unit is pushed in the front tunnel (4) in a direction away from the rear blind tunnel (3), and multiple matching trolleys are assembled in sequence on the side of the shield machine main unit close to the rear blind tunnel (3). A reaction ring beam (19) is cast in the face area of ​​the pilot tunnel (4), and a continuous slag discharge system is installed in the composite space formed by the vertical shaft (2), the pilot tunnel (4) and the rear blind tunnel (3); Once the reaction ring beam (19) reaches the first design strength, the shield machine is started to excavate and advance as a whole, and the continuous slag discharge is carried out through the continuous slag discharge system. The process involves excavating and supporting interconnected vertical shafts (2), a pilot tunnel (4), and a rear blind tunnel (3) in sequence, specifically including the following steps: The vertical shaft was excavated layer by layer (2) and the ring beam was constructed along with the excavation; Simultaneously excavate the pilot tunnel (4) and the rear blind tunnel (3), and perform initial support (16). An initiation platform (21) is constructed in the initiation tunnel (4), and the invert arch of the rear blind tunnel (3) is poured and backfilled with concrete. The continuous slag discharge system includes: The horizontal continuous belt conveyor (14) and the vertical belt conveyor (15) are used in conjunction. The horizontal continuous belt conveyor (14) is installed in the front tunnel (4) and the rear blind tunnel (3), and the vertical belt conveyor (15) is installed in the vertical shaft (2). The horizontal continuous belt conveyor (14) is used to transport the excavated soil generated when the shield machine starts to excavate as a whole to the vertical belt conveyor (15), and the vertical belt conveyor (15) is used to lift the excavated soil to the ground.

2. The method for overall launching of a large-diameter EPB-TBM dual-mode shield tunneling machine with ultra-deep burial depth according to claim 1, characterized in that, The distance between two adjacent ring beams is 8 to 10 meters; a reaction ring beam groove is set in the front guide tunnel (4); the bottom elevation of the rear blind tunnel (3) is 50 cm higher than the bottom elevation of the front guide tunnel (4).

3. The method for overall launching of a large-diameter EPB-TBM dual-mode shield tunneling machine with ultra-deep burial depth according to claim 1, characterized in that, The ring beam near the bottom of the shaft (2) is flush with the top of the arch of the rear blind hole (3); the top surface of the launching base (6) is flush with the top surface of the launching guide platform (21).

4. The method for overall launching of a large-diameter EPB-TBM dual-mode shield tunneling machine with ultra-deep burial depth according to claim 1, characterized in that, The main components of the tunnel boring machine include at least the shield body (9), the cutterhead (7), and the screw conveyor (8); The process of hoisting the main components of the tunnel boring machine into the shaft (2) includes the following steps: Once the launching base (6) reaches the second design strength, the shield (9), the cutterhead (7), and the screw conveyor (8) are sequentially hoisted into the vertical shaft (2).

5. The method for overall launching of a large-diameter EPB-TBM dual-mode shield tunneling machine with ultra-deep burial depth according to claim 1, characterized in that, It also includes the following steps: During the process of the tunnel boring machine main unit moving forward in the pilot tunnel (4), at least three segments (18) are simultaneously assembled at the bottom of the pilot tunnel (4) and grout is injected into the shield wall behind the shield tail gap outside the segments (18) to form a shield wall grouting body (17). A central box culvert (22) is installed in the annular space of the grouting body (17) behind the shield wall.

6. The method for overall launching of a large-diameter EPB-TBM dual-mode shield tunneling machine with ultra-deep burial depth according to claim 5, characterized in that, The starting guide platform (21) has a concave groove in the middle position, and the radius of curvature of the concave groove is equal to the outer radius of curvature of the tube segment (18); the bottom of the central box culvert (22) is arc-shaped, and the radius of curvature of the central box culvert (22) is equal to the inner radius of curvature of the tube segment (18).

7. The method for overall launching of a large-diameter EPB-TBM dual-mode shield tunneling machine with ultra-deep burial depth according to claim 5, characterized in that, The supporting force provided by the reaction ring beam (19) is greater than the water and soil pressure in front of the tunnel boring machine when the machine starts to run; the inner side of the reaction ring beam (19) is flush with the inner side of the assembled segment (18).

8. The method for overall launching of a large-diameter EPB-TBM dual-mode shield tunneling machine with ultra-deep burial depth according to claim 1, characterized in that, With the reaction ring beam (19) as the boundary, the cross section of the guide tunnel (4) near the vertical shaft (2) is horseshoe-shaped, and the cross section of the guide tunnel (4) near the working face is circular, and the central axis of the horseshoe-shaped cross section coincides with the central axis of the circular cross section.

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