Large-diameter shield main machine long-distance empty pushing method

Abstract

The application discloses a long-distance empty pushing method for a super-large-diameter shield main machine, and aims to solve the problem that the shield main machine is difficult to smoothly and reliably pass through a standard section of a starting shaft and move to a main starting shaft at a sub starting shaft in a height-limited area. The method pushes the shield main machine to move along a sliding rail of the standard section of the starting shaft through a counterforce twist leg opposite to the shield main machine, a counterforce seat embedded in barrel grooves on both sides of the standard section of the starting shaft and a stepping hydraulic cylinder arranged between the counterforce twist leg and the counterforce seat, thereby realizing smooth and stepping empty pushing of the shield main machine from the sub starting shaft with relatively loose height limitation to the main starting shaft with relatively strict height limitation, effectively solving the adverse effect of height limitation of a construction area on hoisting and starting of the shield main machine, and realizing safe and efficient empty pushing.

Description

Technical Field

[0001] This invention application relates to the field of tunnel boring machine (TBM) technology, specifically to a long-distance air-propulsion method for an ultra-large diameter TBM main unit. Background Technology

[0002] The rapid development of urban construction and the continuous improvement of intercity rail transit networks have spurred the diversification and development of tunnel boring machine (TBM) technology. With the development and utilization of underground space and the construction of urban municipal pipelines, TBM tunnels worldwide are gradually showing a trend towards being "larger, longer, and deeper."

[0003] For example, a reserved track construction project for an airport transportation hub in Guangzhou adopted the shield tunneling method. The tunnel segments were designed with an outer diameter of Φ13.8m and an inner diameter of Φ12.6m, and were constructed using the China Railway No. 1188 shield tunneling machine. This machine has a cutterhead diameter of 14.31m, a total length of approximately 15.5m, and a weight of approximately 2500t. Due to its large diameter and heavy weight, the shield tunneling machine was hoisted and lowered into the launching shaft in sections. This launching shaft included a main launching shaft, a secondary launching shaft, and a standard section located between the main and secondary launching shafts. Furthermore, because the project is adjacent to the airport area, there were stepped height restrictions in the launching shaft area. This resulted in the shield tunneling machine being hoisted and lowered into the main launching shaft due to airspace height restrictions, meaning the hoisting and lowering of the shield tunneling machine could only be carried out at the secondary launching shaft, where the height restrictions were relatively more relaxed. However, the tunnel boring machine needs to start excavation at the main launching shaft, and the main tunnel boring machine is quite heavy. Therefore, there is a technical problem of how to smoothly move the main tunnel boring machine from the auxiliary shaft to the main shaft.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the background technology of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] In view of at least one of the above technical problems, this disclosure provides a long-distance air-push method for ultra-large diameter shield tunneling main units, which aims to solve the problem that shield tunneling main units are difficult to smoothly and reliably pass through the standard section of the starting shaft and move to the main starting shaft in height-restricted areas.

[0006] According to one aspect of this disclosure, a method for long-distance air-propulsion of an ultra-large diameter tunnel boring machine is provided, comprising the following steps:

[0007] (1) The standard section guide platform is supported in the standard section between the main launching shaft and the auxiliary launching shaft, and several barrel groove pre-embedded parts are arranged in a symmetrical array on both sides of the standard section guide platform, parallel to the axis of the standard section.

[0008] (2) Cast the standard section guide platform. After the standard section guide platform has solidified to the design strength, symmetrically arrange the sliding steel rails at the corresponding positions on both sides of the standard section guide platform.

[0009] (3) Before the shield machine is lowered into the well, a number of arc pads corresponding to and abutting the sliding rail are set at the outer edge of the block where the shield machine contacts the sliding rail. The fitting line between each arc pad is parallel to the sliding rail. Reaction torsion legs that coincide with the shield section are set at the corresponding positions of the shield body on both sides of the shield machine.

[0010] (4) According to Calculate the maximum air thrust friction, where μ is the coefficient of friction. The normal force of the tunnel boring machine on the standard section guide platform is given by α, where α is the angle between the normal stress of the rail and its vertical component; and the maximum air thrust friction is also considered. Select a matching hydraulic pump station and stepper hydraulic cylinder;

[0011] (5) Weld a reaction seat that matches the barrel trough, and the seat of the reaction seat is higher than the top surface of the barrel trough by a certain height and is used to be set opposite to the reaction torsion leg;

[0012] (6) Apply lubricating oil to the sliding rail, and set a reaction seat in the barrel groove pre-embedded part corresponding to the shield tail side of the reaction torsion leg after the shield machine is lowered into the well;

[0013] (7) The stepping hydraulic cylinders are respectively installed between the reaction torsion legs and the reaction seats at the standard section guide platforms on both sides of the shield machine host, and the two stepping hydraulic cylinders are controlled to advance synchronously.

[0014] (8) After the stepping hydraulic cylinder is fully extended and drives the shield machine to step the designed distance, the stepping hydraulic cylinder is depressurized and recovered, and the reaction seats on both sides of the shield machine are moved forward toward the shield cutterhead and into the next barrel groove embedded part.

[0015] (9) Repeat steps (7)-(8) until the shield machine reaches the designated position of the main launching shaft through the standard section.

[0016] In some embodiments of this disclosure, in step (1), the barrel groove embedded part includes a barrel body and an outer edge plate correspondingly disposed on the outside of the barrel body for casting in the standard section guide platform, and the embedded spacing between the barrel groove embedded parts is consistent with the design step distance of the shield machine host.

[0017] In some embodiments of this disclosure, in step (2), the top of the standard section guide platform is provided with an inner arc surface that matches the outer contour of the shield machine host, and the sliding rail is set perpendicular to the inner arc surface.

[0018] In some embodiments of this disclosure, in step (3), the arc pad includes an arc plate with a certain thickness for correspondingly fitting with the outer contour of the shield machine host, and an end plate disposed on the corresponding end side of the arc plate for abutting against the sliding rail; the thickness of the arc plate is greater than the radius difference between the cutterhead and the shield shell.

[0019] In some embodiments of this disclosure, in step (3), the height of the reaction torsion leg is matched with the height of the top surfaces on both sides of the standard section guide platform; and the reaction torsion leg is provided with a rib plate between it and the shield body.

[0020] In some embodiments of this disclosure, in step (4), the load safety factor of the stepping hydraulic cylinder is 1.3, and its actual load is half of the maximum air thrust friction.

[0021] In some embodiments of this disclosure, in step (5), the reaction seat includes a seat body for being embedded in the barrel groove and an angular reinforcing plate disposed on one side of the seat body and for correspondingly abutting against the top surface of the standard section guide.

[0022] In some embodiments of this disclosure, in step (7), a steel profile is provided between the stepping hydraulic cylinder and the reaction torsion leg or reaction seat for axial support along the stepping hydraulic cylinder.

[0023] One or more technical solutions provided in the embodiments of this application have at least one of the following technical effects or advantages:

[0024] 1. By using reaction torsion legs that are fixed relative to the shield machine, reaction seats embedded in the grooves on both sides of the standard section guide platform, and stepping hydraulic cylinders located between the reaction torsion legs and reaction seats, the shield machine is pushed to move along the sliding rails of the standard section guide platform. This enables the shield machine to move smoothly and steadily from the secondary launch shaft, where the height limit is relatively loose, to the main launch shaft, where the height limit is relatively strict. This effectively solves the adverse effects of height restrictions in the construction area on the hoisting and launch of the shield machine.

[0025] 2. The reaction seat embedded in the barrel groove can effectively and reliably transfer the load when the stepping hydraulic cylinder is pushed forward to the standard section guide platform, avoiding the low construction efficiency and increased cost caused by adding supporting force structure in the limited space of the standard section.

[0026] 3. The arc-shaped pads, which correspond to and are relatively fixed to the outer contour of the shield machine, serve two purposes. First, by having a thickness greater than the radius difference between the cutterhead and the shield shell, they prevent wear between the cutterhead and the sliding rails when the shield machine is pushed along the guide rails of the standard section. Second, by using end plates that abut against the sliding rails, they limit the path of the shield machine during empty pushing, preventing the shield from twisting and ensuring the effectiveness of the empty pushing. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the standard section guide platform in one embodiment of this application.

[0028] Figure 2 This is a schematic diagram of the shield tunneling machine's stepping state in one embodiment of this application.

[0029] In the above figures, 1 is the standard section guide platform, 2 is the barrel trough embedded part, 3 is the shield machine host, 4 is the sliding rail, 5 is the arc pad, 6 is the stepping hydraulic cylinder, 7 is the reaction seat, 8 is the structural steel, and 9 is the reaction torsion leg. Detailed Implementation

[0030] To better understand the technical solution of this application, the above technical solution will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] The reserved track construction project for the Baiyun Airport T3 transportation hub is located within the airport's red line area, west of the Airport Second Expressway, east of Airport Avenue, and south of Baiyun Airport T3 Terminal in Baiyun District. It includes the main station structure and the reserved civil engineering works for the sections at both ends of the station within the airport red line area. The reserved civil engineering works for the sections at both ends of the station within the red line are entirely underground structures. Except for the open-cut section connecting to the station's open-cut foundation pit, all other sections will be constructed using the shield tunneling method. The shield tunnel segments are designed with an outer diameter of Φ13.8m, an inner diameter of Φ12.6m, a structural thickness of 0.6m, and a width of 2m. The equipment used in this project is the China Railway 1188 shield tunneling machine, with a cutterhead excavation diameter of 14.31m, a main machine length of approximately 15.5m, and a total machine length of approximately 115m (excluding the tail towing platform); the main machine weighs approximately 2500t.

[0032] The hoisting site for this project is adjacent to Baiyun Airport, with a complex surrounding environment and numerous overlapping operations, making coordination difficult. Furthermore, the Guangzhu-Macau launch shaft within the construction area is adjacent to the airport's East Second Runway, and there are stepped height restrictions ranging from 16m to 30m above the main launch shaft to the auxiliary launch shaft. Therefore, hoisting operations will be carried out at the auxiliary launch shaft, where the height restrictions are relatively relaxed. After the tunnel boring machine (TBM) is assembled at the auxiliary launch shaft, it will be moved horizontally to the main launch shaft for initial excavation.

[0033] To address this issue, this example discloses a long-distance air-push method for ultra-large diameter shield tunneling machines, aiming to solve the problem of smoothly moving a heavy shield tunneling machine from the auxiliary launching shaft to the main launching shaft over a long distance. The method specifically includes the following steps:

[0034] (1) The standard section guide platform is supported in the standard section between the main launching shaft and the auxiliary launching shaft, and several barrel groove pre-embedded parts are arranged in a parallel array on both sides of the standard section guide platform.

[0035] After the launching shaft is dug, its bottom has a square groove structure. Considering that the tunnel boring machine (TBM) is cylindrical, launching guide platforms are poured at both the main and auxiliary launching shafts to facilitate stable movement of the TBM. Furthermore, for convenient and reliable air-pushing, standard section guide platforms are poured at the marked section of the launching shaft. See details... Figure 1 The top of the standard section guide platform 1 is an arc-shaped structure that corresponds to the outer contour of the shield machine, so as to provide good support for the shield machine. Considering that the shield machine needs certain force support points to provide reaction force when it is pushed forward, in order to avoid the occupation of the limited working space of the standard section and the increase in construction costs caused by adding new support structures, in this embodiment, when the standard section guide platform is cast, several barrel groove embedded parts 2 are arranged on the top of the standard section guide platform. The barrel groove embedded parts 2 specifically include prism-shaped barrels with a certain depth, so as to securely fit the reaction seat set in the barrel body later, and prevent the reaction seat from being pulled out after being stressed, which would lead to the failure of the push-forward. Furthermore, to further enhance the fixing strength of the barrel-shaped embedded part within the standard section guide platform, an outer edge plate is provided on the outside of the barrel for casting within the standard section guide platform. In this embodiment, an outer edge plate perpendicular to each side is provided on three sides of the embedded part barrel. No outer edge plate is provided on the side of the barrel near the arc-shaped surface of the standard section guide platform to avoid the outer edge plate extending to the arc-shaped surface of the guide platform and interfering with the tunnel boring machine, thus preventing damage to the tunnel boring machine. The outer edge plates on the remaining sides are respectively located at the top edge perpendicular to each side, so that during the casting of the standard section guide platform 1, the outer edge plate is positioned at the top surface of the standard section guide platform 1. This strengthens the pre-embedded strength of the barrel-shaped embedded part while providing support for the subsequent reaction seat through the outer edge plate parallel to and fitted into the surface of the standard section guide platform 1, allowing the air thrust reaction load to be distributed relatively evenly to the standard section guide platform. In addition, in this embodiment, in order to facilitate the empty thrusting of the shield machine, the pre-embedded spacing of the barrel groove pre-embedded part 2 is consistent with the designed stepping distance of the shield machine. Considering the force balance during the empty thrusting of the shield machine, the barrel groove pre-embedded part is symmetrically set on both sides of the standard section guide platform and symmetrical about the vertical cross section of the standard section passing through the central axis of the standard section. This ensures that the shield machine is subjected to consistent forces on both sides during subsequent empty thrusting, thereby avoiding the problem of the shield machine twisting, tilting or even deviating from the central axis of the standard section.

[0036] (2) Cast the standard section guide platform. After the standard section guide platform has solidified to the design strength, symmetrically arrange the sliding steel rails at the corresponding positions on both sides of the standard section guide platform.

[0037] After the standard section guide platform formwork support and the embedded parts of the barrel trough are installed and fixed, the standard section guide platform can be poured. In this embodiment, in order to adapt to the arc-shaped structure of the outer edge of the tunnel boring machine and considering the convenience of pouring, see [reference needed]. Figure 1In this embodiment, the top of the standard section guide platform is symmetrically provided with cross-sections tangent to the outer contour of the shield machine 3. In other embodiments, the top of the standard section guide platform is provided with an arc-shaped surface matching the outer contour of the shield machine. Furthermore, considering the relatively long length of the standard section, the shield machine's direct contact with the guide platform during empty thrust along the standard section guide platform would lead to significant friction and wear. Therefore, in this embodiment, sliding rails 4 are respectively provided at each cross-section of the top of the standard section guide platform. In this example, four sliding rails 4 are symmetrically arranged on both sides of the standard section guide platform 1 to provide good support for the shield machine. To facilitate the fixed installation of each sliding rail 4, in this example, each sliding rail 4 is fixedly installed perpendicular to the standard section guide platform 1.

[0038] (3) Before the shield machine is lowered into the well, a number of arc pads corresponding to and abutting the sliding rail are set at the outer edge of the block where the shield machine contacts the sliding rail. The fitting line between each arc pad is parallel to the sliding rail. Reaction torsion legs that coincide with the shield section are set at the corresponding positions of the shield body on both sides of the shield machine.

[0039] Even after symmetrically installing sliding rails on the standard section guide platform, friction and wear still exist between the tunnel boring machine (TBM) and the sliding rails, affecting the TBM's performance and potentially causing damage. Furthermore, when the TBM is pushed along the sliding rails without load, there is a significant risk of torsion under unbalanced thrust from both sides, causing the TBM to deviate from its central axis. Therefore, in this embodiment, arc-shaped pads are welded to corresponding positions on the bottom of the TBM. (See [reference]). Figure 1In this example, sections 4, 5, and 6 of the tunnel boring machine (TBM) are in contact with the sliding rails 4. Therefore, arc-shaped pads 5, corresponding to the sliding rails, are welded and fixed to the outer edges of sections 4, 5, and 6. Each arc-shaped pad 5 includes an arc plate that conforms to the outer contour of the TBM 3, and an end plate located on the corresponding end of the arc plate to abut against the sliding rails. During use, the arc plate is welded to the TBM, achieving relative fixation between the arc-shaped pads 5 and the TBM 3. The end plate is located at the end of the arc-shaped surface of the arc plate, passing through the chord of the corresponding section. This locking and limiting action between the end of the arc-shaped pad and the sliding rails prevents torsion of the TBM during force-driven advancement. Furthermore, the indirect contact between the TBM and the sliding rails via the arc plate avoids direct friction, effectively protecting the structural integrity of the TBM and preventing friction damage. Furthermore, due to the radius difference between the shield cutterhead and the shield host body, the diameter of the cutterhead is slightly larger than the diameter of the shield host body. This leads to the risk of friction between the shield cutterhead and the sliding rail during the shield host's no-load thrust. Therefore, in this embodiment, the arc plate of the arc pad 5 has a certain thickness, which is greater than the radius difference between the shield cutterhead and the shield host body. Thus, the arc pad ensures that the outer edge of the shield host body is at a certain safe distance from the sliding rail, avoiding wear between the shield cutterhead and the sliding rail.

[0040] To provide support points for the shield machine during air thrust, in this embodiment, reaction torsion legs with circular cross-sections are set on both sides of the shield machine. To avoid interference between the reaction torsion legs and the standard section guide platform, the height of the reaction torsion legs matches the height of the top surfaces on both sides of the standard section guide platform. In this example, the bottom of the reaction torsion legs is 3cm away from the top surfaces on both sides of the standard section guide platform. In addition, to ensure the force balance during air thrust of the shield machine, the reaction torsion legs are symmetrically set on both sides of the shield machine. This is because the shield machine is relatively heavy, and the reaction torsion legs are set perpendicular to the outer edge of the shield machine. To ensure the strength of the reaction torsion legs, in this example, ribs are provided between the reaction torsion legs and the shield body.

[0041] (4) According to Calculate the maximum air thrust friction, where μ is the coefficient of friction. The normal force of the tunnel boring machine on the standard section guide platform is given by α, where α is the angle between the normal stress of the rail and its vertical component; and the maximum air thrust friction is also considered. Select a matching hydraulic pump station and stepper hydraulic cylinder.

[0042] To select a suitable air thrust for the tunnel boring machine (TBM), the air thrust friction is first calculated. Since the sliding rails are perpendicular to the corresponding surface of the standard section guide platform, the angle α between the normal stress and the vertical component of the force on the rails needs to be considered. Furthermore, considering that the TBM is positioned above symmetrical sliding rails, the calculation is then based on… Calculate the maximum air thrust friction. In this example, the calculated maximum air-thrust friction between the shield main unit and the sliding rail is approximately 614t. However, considering the force exerted on both sides of the shield main unit during propulsion, a corresponding hydraulic cylinder is selected as the stepping hydraulic cylinder. The load of this hydraulic cylinder must be greater than half of the maximum air-thrust friction. In addition, considering the redundancy of construction safety, in this example, the load safety factor of the stepping hydraulic cylinder is set to 1.3 to leave a load margin for the stepping hydraulic cylinder. That is, the load of the stepping hydraulic cylinder is half of the maximum air-thrust friction multiplied by the safety factor, which is approximately 399t. Therefore, a stepping hydraulic cylinder with a load of 400t is selected.

[0043] (5) Weld a reaction seat that matches the tank trough, and the seat of the reaction seat is higher than the top surface of the tank trough by a certain height and is used to be set opposite to the reaction torsion leg.

[0044] The reaction torsion leg provides support for the shield tunneling machine's thrust. To facilitate the thrusting operation of the shield tunneling machine using the standard section guide platform, in this embodiment, a reaction seat matching the pre-embedded part of the standard section slot is provided. This reaction seat includes a seat body for embedding in the slot pre-embedded part and an angled reinforcing plate located on one side of the seat body and corresponding to and abutting against the top surface of the standard section guide platform. The seat body embedded in the slot pre-embedded part achieves relative fixation when the reaction seat is subjected to force along the direction of the standard section guide platform. Since the seat body is higher than the top surfaces on both sides of the standard section guide platform by a certain height and is opposite to the reaction torsion leg, it provides force support for the stepping hydraulic cylinder. Furthermore, considering the heavy weight of the tunnel boring machine (TBM) and the long thrust distance, the reaction seat needs to be reused. To prevent deformation of the reaction seat, in this embodiment, an angular reinforcing plate is provided at the top of the rear side of the reaction seat along the force direction. This reinforcing plate is set perpendicular to the side of the reaction seat and one side is used to abut against the outer edge plate of the pre-embedded part of the standard section guide groove. This ensures that the reaction seat can effectively and reliably transfer the load to the standard section guide after being subjected to force, thus ensuring the smooth advance of the TBM during thrust.

[0045] (6) Apply lubricating oil to the sliding rail and set the reaction seat in the barrel groove pre-embedded part corresponding to the shield tail side of the reaction torsion leg after the shield machine is lowered into the well.

[0046] To further reduce friction between the tunnel boring machine (TBM) and the sliding rails during its stepping motion, in this embodiment, grease is applied to the sliding rails for lubrication before the TBM is lowered into the shaft for air thrusting, ensuring smooth subsequent TBM air thrusting operations. After the TBM is lowered into the shaft, reaction seats are placed in the corresponding pre-embedded parts of the barrel slot, ensuring a certain distance between the reaction torsion legs and the reaction seats to accommodate the stepping hydraulic cylinders. During installation, steel plates are inserted into the gap between the reaction seats and the barrel slot pre-embedded parts for fixation and limiting, preventing the reaction seats from shaking within the barrel slot pre-embedded parts.

[0047] (7) Stepping hydraulic cylinders are installed between the reaction torsion legs and reaction seats at the standard section guide platforms on both sides of the shield machine to control the synchronous advancement of the two stepping hydraulic cylinders.

[0048] See Figure 2 Stepping hydraulic cylinders 6 are installed on the top surface of the standard guide platforms on both sides of the shield machine 3. One end of the hydraulic cylinder abuts against the reaction seat 7, and the other end abuts against the reaction torsion leg 9 through the steel section 8. The reaction torsion leg 9, the steel section 8, the stepping hydraulic cylinder 6, and the reaction seat 7 are arranged coaxially to maximize the effective output of the power generated by the stepping hydraulic cylinder. In addition, the steel section 8 located between the stepping hydraulic cylinder 6 and the reaction torsion leg 9 increases the distance between the reaction torsion leg 9 and the reaction seat 7. This avoids the reaction seat being located on the side of the shield machine, thus allowing it to be located outside the shield tail. This prevents the shield machine from interfering with the hoisting equipment used to install the reaction seat during installation. Furthermore, the reaction seat located at the shield tail allows it to be placed closer to the shield machine, thereby reducing the distance between the stepping hydraulic cylinder and the shield machine, and enabling the thrust of the stepping cylinder to be more effectively transmitted to the shield machine for dry thrust. In this example, H-shaped steel is used to ensure its strength under load. In some other embodiments, the other end of the stepping hydraulic cylinder directly contacts the reaction torsion leg 9 for air thrust.

[0049] After the stepping hydraulic cylinders 6 are symmetrically installed on both sides of the shield machine, the two stepping hydraulic cylinders 6 are controlled to extend synchronously, driving the shield machine to move smoothly along the sliding rail towards the main launching shaft.

[0050] (8) After the stepping hydraulic cylinder is fully extended and drives the shield machine to step the designed distance, the stepping hydraulic cylinder is depressurized and recovered, and the reaction seats on both sides of the shield machine are moved forward toward the shield cutterhead and into the next barrel groove embedded part.

[0051] Since the standard section has a certain length, the shield machine cannot be pushed into place in one go. Therefore, in this embodiment, after the stepping hydraulic cylinder extends to the designed length, the stepping hydraulic cylinder is depressurized and recovered, and the position of the reaction seat is adjusted so that the reaction seat moves forward to the position of the next barrel groove embedded part, and then the next stepping air push is carried out, thereby achieving the purpose of long-distance air push of the shield machine.

[0052] (9) Repeat steps (7)-(8) until the shield machine reaches the designated position of the main launching shaft through the standard section.

[0053] Although some preferred embodiments of this invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0054] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of the invention. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A long-distance air-propulsion method for ultra-large diameter shield tunneling machines, characterized in that, Includes the following steps: (1) The standard section guide platform is supported in the standard section between the main launching shaft and the auxiliary launching shaft, and several barrel groove embedded parts are arranged in a symmetrical array on both sides of the standard section guide platform, parallel to the axis of the standard section. The barrel groove embedded part includes a barrel body and an outer edge plate corresponding to the outside of the barrel body for casting in the standard section guide platform. The embedded spacing between the barrel groove embedded parts is consistent with the design step distance of the shield machine. (2) The standard section guide platform is poured. After the standard section guide platform solidifies to the design strength, four sliding steel rails perpendicular to the standard section guide platform are symmetrically arranged at the corresponding arc-shaped top positions on both sides of the standard section guide platform. The top of the standard section guide platform is provided with an inner arc surface that matches the outer contour of the shield machine host. The sliding steel rails are set perpendicular to the inner arc surface. (3) Before the shield machine is lowered into the shaft, a number of arc-shaped pads are set at the outer edge of the block where the shield machine contacts the sliding rail, and the fitting line between each arc-shaped pad is parallel to the sliding rail; and reaction torsion legs are set at the corresponding positions of the shield body on both sides of the shield machine, which coincide with the cross section of the shield body at that position; the arc-shaped pad includes an arc plate with a certain thickness for corresponding fitting with the outer contour of the shield machine, and an end plate set on the corresponding end side of the arc plate for abutting against the sliding rail; the thickness of the arc plate is greater than the radius difference between the cutterhead and the shield shell; (4) According to F max = μ ×2× Calculate the maximum air-pushing friction force, where μ is the friction coefficient, F1 is the normal force of the tunnel boring machine on the standard section guide platform, and α is the angle between the normal stress of the rail and the vertical component of the force; and based on the maximum air-pushing friction force F... max Select a matching hydraulic pump station and stepping hydraulic cylinder; the load safety factor of the stepping hydraulic cylinder is 1.3, and its actual load is half of the maximum air thrust friction. (5) Weld a reaction seat that matches the barrel trough, and the seat of the reaction seat is higher than the top surface of the barrel trough by a certain height and is used to be set opposite to the reaction torsion leg; (6) Apply lubricating oil to the sliding rail, and set a reaction seat in the barrel groove pre-embedded part corresponding to the shield tail side of the reaction torsion leg after the shield machine is lowered into the well; (7) The stepping hydraulic cylinders are respectively installed between the reaction torsion leg and the reaction seat at the standard section guide platform on both sides of the shield machine host, and the two stepping hydraulic cylinders are controlled to advance synchronously; a steel profile is provided between the stepping hydraulic cylinder and the reaction torsion leg or the reaction seat for axial support along the stepping hydraulic cylinder. (8) After the stepping hydraulic cylinder is fully extended and drives the shield machine to step the designed distance, the stepping hydraulic cylinder is depressurized and recovered, and the reaction seats on both sides of the shield machine are moved forward toward the shield cutterhead and into the next barrel groove embedded part. (9) Repeat steps (7)-(8) until the shield machine reaches the designated position of the main launching shaft through the standard section.

2. The long-distance air-propulsion method for ultra-large diameter shield tunneling machines according to claim 1, characterized in that, In step (3), the height of the reaction torsion leg is matched with the height of the top surfaces on both sides of the standard section guide platform; and the reaction torsion leg is provided with a rib plate between it and the shield body.

3. The long-distance air-propulsion method for ultra-large diameter shield tunneling machines according to claim 1, characterized in that, In step (5), the reaction seat includes a seat body for being embedded in the barrel groove pre-embedded part, and an angular reinforcing plate disposed on one side of the seat body and for correspondingly abutting against the top surface of the standard section guide platform.

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