A shield launching construction method of a steel gun support reaction force system replacing a type steel reaction frame

Abstract

The present application relates to the technical field of shield construction, in particular to a kind of steel cannon bracing reaction system replacement type steel reaction frame's shield launching construction method, comprising the following steps: excavating foundation pit, the launching base and circular arc section structure of reinforced concrete structure are constructed;Shield launching machine is hoisted, and assembly debugging is carried out;First annular steel plate is embedded on the circular arc section structure, and negative ring segment is assembled along the first annular steel plate;Multiple steel cannon bracing are evenly distributed and arranged along the first annular steel plate;Step five: hole door is broken, and hole door is treated by adopting air pick to be pulverized layered and chiseled, launching advances, and excavates forward;Steel cannon bracing reaction system formed by the circular arc section structure cooperates with steel cannon bracing structure, which can replace traditional type steel reaction frame construction, simple structure, convenient construction, is conducive to saving construction period;More stable support structure is obtained by relying on circular arc section structure, reduces tensile and compressive failure probability, can provide sufficient reaction support, is conducive to improving shield launching efficiency.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology, specifically to a TBM launching method that uses a steel cannon-bracing reaction system to replace a steel reaction frame. Background Technology

[0002] Currently, during the shield tunneling launch process, it is usually necessary to set up a reaction frame behind the shield body. The shield launch reaction frame device is generally an inner octagonal portal frame structure, usually made of steel. Steel pipe supports are installed in the opposite direction of the octagonal portal frame structure. It is installed in the shield working shaft to provide reaction force for tunneling during the shield launch.

[0003] However, traditional steel reaction frames have the following problems in the launching of large-diameter shield tunnels: compared with small-diameter shield tunnels, large-diameter shield tunnels require larger reaction frames with very complex structures, high assembly and disassembly difficulty, and high precision requirements for nodes; they cannot be reused for shields of different diameters, resulting in high operating costs; traditional steel reaction frames have heavy lifting weights and high safety risks, requiring at least four people to perform welding operations at a height of 10 meters, and inadequate edge protection could potentially cause mass casualties; the construction process of traditional steel reaction frames is complicated, with a large amount of welding work, generally taking more than two weeks, which could potentially delay the construction schedule. Therefore, considering the need to simplify construction, reduce construction difficulty, reduce investment costs, avoid construction risks, and shorten construction time, thereby making shield tunnel launching more efficient and safer, we propose a steel cannon-braced reaction system to replace the steel reaction frame in shield tunnel launching construction methods. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings mentioned in the background art and provide a shield tunneling initiation method that uses a steel cannon-support reaction system to replace a steel reaction frame.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for shield tunneling initiation construction that uses a steel cannon-bracing reaction system to replace a steel reaction frame, the method comprising the following steps:

[0007] Step 1, reinforcement of the launching shaft: High-pressure jet grouting concrete is injected to reinforce the area within 5m outside the launching shaft and within 5m from the bottom of the launching shaft. Vertical core sampling of the jet grouting concrete is performed after 28 days.

[0008] Step 2: Excavation and construction of the launching shaft and launching base: The compressive strength of the core sample should not be less than 1.2 MPa, and the permeability coefficient should not be less than 1×10⁻⁶. -7 The starting working shaft is excavated at a speed of cm / s. A reinforced concrete starting base is poured at the bottom of the starting working shaft, and steel rails are installed on the starting base to provide a sliding surface for the tunnel boring machine.

[0009] Step 3, excavation of the arc-shaped cross-section structure: construct the arc-shaped cross-section structure, setting the inner diameter of the arc-shaped cross-section structure to be 12.1±0.1m and the thickness to be 0.8±0.02m;

[0010] A first annular steel plate for corresponding installation of negative ring segments is pre-embedded in the arc cross-section structure. The thickness of the first annular steel plate is 30±2mm and the width is 600±5mm. The negative ring segments are assembled along the first annular steel plate.

[0011] Step 4, hoisting and assembling the tunnel boring machine: Assemble the tunnel boring machine inside the working shaft, hoist the tunnel boring machine onto the rails of the starting base, and perform assembly and debugging;

[0012] Step 5, Construction of the steel cannon support reaction system: Multiple steel cannon supports are evenly distributed along the first annular steel plate to replace the traditional steel reaction frame. One end of the steel cannon support is welded to the arc section structure through the first annular steel plate, and the other end is installed with a second annular steel plate with a thickness of 20±2mm and a width of 500±5mm and welded to the negative ring segment.

[0013] Step Six, Cave Entrance Demolition: Use a pneumatic drill to break down the cave entrance into shredding layers;

[0014] Step 7, Initial Advancement: The tunnel boring machine advances forward.

[0015] Preferably, L-shaped reinforcing bars are welded to the first annular steel plate for anchoring connection with the arc-shaped cross-section structure, and the L-shaped reinforcing bars and the first annular steel plate are connected by double-sided lap welding of 100±5mm.

[0016] Preferably, the L-shaped reinforcing bars are distributed at a 2.5° angle along the circumference of the first annular steel plate.

[0017] Preferably, the negative ring segment has 8-10 rings.

[0018] Preferably, the second annular steel plate is connected to the negative ring segment by anchor bars, and the anchor bars are set with a length of 300±5mm and arranged in two rows in a ring.

[0019] Preferably, the anchor bars are distributed at a 1.4° angle along the circumferential direction of the second annular steel plate.

[0020] Preferably, there are 36 steel gun supports, and the installation positions of the steel gun supports are offset from the connection seams of the negative ring segments by a distance of not less than 5cm.

[0021] Preferably, the opening has 16 excavation areas arranged sequentially from top to bottom and from left to right, and the excavation areas are excavated in at least two separate steps.

[0022] Preferably, the starting base includes a base base with rails and side bases symmetrically arranged on the left and right sides of the base base, with each side base pre-embedded with 200×200mm H-beams for installing the rails.

[0023] Preferably, the length of the steel gun support is between 1993-2287 mm, and at least four steel gun supports are provided, each equipped with an axial force gauge and evenly distributed. The axial force gauge is used to monitor the force.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] This steel cannon-support reaction system replaces the traditional steel reaction frame method for shield tunneling. It utilizes a circular arc cross-section structure in conjunction with the steel cannon-support structure to form the steel cannon-support reaction system, replacing traditional steel reaction frame construction. Its simple structure and convenient assembly / disassembly make it suitable for large shield tunneling projects of varying diameters, significantly reducing costs. This steel cannon-support reaction system eliminates the need for large crawler cranes, minimizing high-altitude work and effectively controlling safety risks. The construction process is simple, with minimal welding work, requiring only 2-3 days, significantly shortening the construction period. Simultaneously, the circular arc cross-section structure provides a more stable support structure, reducing the probability of tensile and compressive failure of the negative ring segments and providing sufficient reaction support, thus improving shield tunneling launch efficiency. Attached Figure Description

[0026] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 This is a schematic diagram of the shield tunnel inlet structure of the present invention;

[0028] Figure 2 This is a cross-sectional view of the working well from which the invention was first developed;

[0029] Figure 3 This is a side view of the construction process of the present invention;

[0030] Figure 4 This is a schematic diagram of the steel cannon support construction distribution of the present invention;

[0031] Figure 5 This is a schematic diagram of the pre-embedded anchor bars for the negative ring segment of the present invention;

[0032] Figure 6 This is a flowchart illustrating the construction process of this invention.

[0033] The meanings of the labels in the diagram are as follows:

[0034] 1. Anchor bar; 2. Tunnel boring machine; 3. Diaphragm wall; 4. Top slab; 5. Side wall; 6. Bottom slab; 7. Backfill soil; 8. Circular arc section structure; 9. Negative ring segment; 10. First ring steel plate; 11. Portal; 12. Rail; 13. Steel support; 14. Second ring steel plate; 15. H-beam. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see Figure 1-6 The present invention will describe the above technical solution in detail through the following embodiments:

[0037] A method for shield tunneling initiation construction that uses a steel cannon-bracing reaction system to replace a steel reaction frame includes the following steps:

[0038] Step 1, Reinforcement of the Launch Shaft: This step is to ensure the solidity of the surrounding soil base during the shield tunneling launch to guarantee safety. High-pressure jet grouting piles are used to reinforce the end of the launch shaft. In this embodiment, the longitudinal length of the reinforcement area is set at 20m, with 5m extending to the outer side of the launch shaft on each side. The reinforcement depth is 5.0m below the bottom slab of the launch shaft. High-pressure jet grouting concrete is used for reinforcement. After 28 days of reinforcement construction, vertical core sampling is conducted to test the foundation reinforcement.

[0039] Step 2: Excavation and construction of the launching shaft and launching base: The compressive strength of the core sample should not be less than 1.2 MPa, and the permeability coefficient should not be less than 1×10⁻⁶. -7 If the speed is less than cm / s, the starting shaft should be excavated. If this does not meet the requirements, reinforcement measures such as horizontal grouting and re-jetting should be immediately implemented to ensure the safety of the shield tunneling launch. Figure 2 The cross-sectional view of the starting working shaft shown shows that a reinforced concrete starting base is poured at the bottom of the starting working shaft. Before the starting base is made, the starting position needs to be re-measured by the surveying team to clarify the positional deviation. During the construction of the starting base, two 200×200mm H-beams 15 are pre-embedded in each section, and two steel rails 12 are arranged longitudinally symmetrically to provide sliding for the tunnel boring machine 2.

[0040] Step 3, excavate the arc-shaped cross-section structure: such as Figure 1This is a schematic diagram of the shield tunnel inlet structure. This diagram shows the effect after the construction of the arc-shaped cross-section structure 8 in the open-cut section. Construction of the arc-shaped cross-section structure 8 requires excavating an open-cut foundation pit. The arc-shaped cross-section structure 8 is set at the inlet open-cut section. First, a diaphragm wall 3 is constructed as the retaining structure. After the excavation reaches the bottom, the bottom slab 6, side walls 5, and top slab 4 are constructed sequentially, and the backfill soil 7 is backfilled to the ground surface elevation. In this embodiment, the inner diameter of the arc-shaped cross-section structure is 12.1m, and the thickness is 0.8m. A first annular steel plate 10 is pre-embedded on the arc-shaped cross-section structure 8, and a second... A ring-shaped steel plate 10 is 30mm thick and 600mm wide. Negative ring segments 9 are assembled along the first ring-shaped steel plate 10. In this embodiment, L-shaped steel bars are welded on the first ring-shaped steel plate 10 for anchoring connection with the arc-shaped cross-section structure 8. The L-shaped steel bars and the first ring-shaped steel plate 10 are connected by double-sided lap welding of 100mm. At the same time, the L-shaped steel bars are distributed at 2.5° along the circumference of the first ring-shaped steel plate. This construction is to maintain a tight installation with the arc-shaped cross-section structure, obtain uniform stress, and serve as a reaction support base.

[0041] Step 4, hoisting and assembling the tunnel boring machine: A 400-ton crawler crane is used to hoist the tunnel boring machine 2 into the starting working shaft in sections, and to assemble and debug it in the shaft to ensure that the mechanical equipment meets the starting conditions. The tunnel boring machine 2 is installed on the steel rail 12 of the starting base for assembly and debugging.

[0042] Step 5, Construction of the steel cannon support reaction system: (e.g.) Figure 4 The diagram shows the construction distribution of the steel support structure. 36 steel supports 13 are evenly distributed along the first annular steel plate 10 to replace the traditional steel reaction frame. In this embodiment, one end of each steel support 13 is welded to the arc-shaped cross-section structure 8 via the first annular steel plate 10, and the other end is welded to the negative ring segment 9. A second annular steel plate 14, 20mm thick and 500mm wide, is installed at the other end of the negative ring segment 9. It should be noted that the angle of the steel supports 13 needs to be adjusted downwards during welding to ensure no eccentric force occurs. Each steel support 13 requires a steel wire rope hanging measure, and four triangular steel ribs are welded to each end of each steel support 13 to increase the weld area. Figure 3 As shown, eight assembled annular negative ring segments 9 are arranged sequentially. The diagram shows that a total of -8 to -1 rings are required at the start. Each ring is a reinforced concrete structure. The outer diameter of the assembled nine negative ring segments 9 is 13.3m, and the inner diameter is 12.2m. Figure 3 As shown, the -8 ring negative ring segment is set as the first ring, and the second ring steel plate 14 is installed on one side of the steel gun support 13 corresponding to the -8 ring; the second ring steel plate 14 is connected to the negative ring segment 9 through anchor bars 1, and the anchor bars are set with a length of 300mm and two rows are arranged in a ring. The anchor bars 1 are distributed along the second ring steel plate 14 in a circumferential direction.

[0043] The tunnel boring machine (TBM) 1 moves forward and assembles the remaining negative ring segments. The assembled and debugged TBM 1 is supported by the -8 negative ring and the steel cannon support 13, and moves forward via the steel rail 12 on the starting base. As the TBM moves forward 2m, the remaining negative ring segments 9 from -7 to -2 are assembled in sequence. Each ring is fastened with 18 M36 high-strength bolts, and the rings are fastened with 50 M36 high-strength bolts. After the entire ring is assembled, a U-shaped buckle is welded using 2cm thick steel plates.

[0044] Step Six, Portal Removal: Use a pneumatic drill to pulverize and remove portal 11 in layers. Erect steel scaffolding beforehand and prepare all necessary equipment for the portal 11 removal. Begin removing portal 11 only after ensuring the tunnel boring machine (TBM) is in good working order. The removal will be carried out in two stages. The diaphragm wall 3 will be removed in layers and sections, from top to bottom, totaling 16 sections. Concrete and some reinforcing steel will be removed sequentially and promptly removed. To ensure the reinforcement effect of the high-pressure jet grouting piles in the starting shaft, the depth of each removal step should be strictly controlled. The first removal will be 15cm to facilitate sequential work, and the second removal will be 65cm, leaving 20cm remaining. After removal, a vertical cross-section will be formed, and the downward slope of the TBM starting tunnel will no longer be considered. Throughout the removal operation, close attention should be paid to the reinforcement effect of the outer soil. Based on the actual situation, portal 11 will be safely removed, and the removed concrete should be cleaned up promptly.

[0045] Step 7, Initial Advancement: Tunnel boring machine 2 advances forward, passing through the extended steel ring and pre-embedded steel ring installed inside the tunnel to prevent sudden water inrush, and then contacts the broken face and excavates the soil. During the process, construction monitoring and grouting to seal leaks should be carried out to ensure the safe start of tunnel boring machine 2. When the tunnel has been excavated to the point where the ground provides enough friction to provide sufficient reaction force for tunnel boring machine 2, dismantling work can be carried out in sequence. At this point, the tunnel boring machine launch work is completed.

[0046] It is important to explain that this construction method differs from the traditional steel reaction frame construction method in that: Instead of using a steel reaction frame, it utilizes the arc-shaped cross-section structure formed by the deep excavation required for shield tunneling. A first annular steel plate 10 is installed on the arc-shaped cross-section structure 8, and steel supports 13 are used to support the negative ring segment 9 on which a second annular steel plate 14 is installed. This reaction system, based on the arc-shaped cross-section structure 8, provides robust support for the shield's initial launch, obtaining sufficient reverse force to propel the shield machine 2 forward. The steel supports are hydraulic cylinder devices that provide a movement range for the shield during its movement. In this embodiment, four steel supports equipped with axial force gauges and evenly distributed are used to monitor the force. If any abnormality is detected, the jacking process is immediately stopped. Specifically, this embodiment uses steel supports with a diameter of 400mm, a wall thickness of 20mm, and made of Q345 steel.

[0047] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0048] Furthermore, if the embodiments of the present invention involve descriptions such as "first," "second," etc., these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description; therefore, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention.

Claims

1. A method for shield tunneling initiation construction using a steel cannon-bracing reaction system to replace a steel reaction frame, characterized in that: The construction method includes the following steps: Step 1, reinforcement of the launching shaft: High-pressure jet grouting concrete is injected to reinforce the area within 5m outside the launching shaft and within 5m from the bottom of the launching shaft. Vertical core sampling of the jet grouting concrete is performed after 28 days. Step 2: Excavation and construction of the launching shaft and launching base: The core sample compressive strength should be no less than 1.2 MPa and the permeability coefficient should be no less than 1×10⁻⁶. -7 The starting working shaft is excavated at a speed of cm / s. A starting base with reinforced concrete structure is poured at the bottom of the starting working shaft. A steel rail (12) is installed on the starting base to provide a sliding surface for the tunnel boring machine (2). Step 3, excavate the arc section structure: construct the arc section structure (8), and set the inner diameter of the arc section structure (8) to be 12.1±0.1m and the thickness to be 0.8±0.02m; A first annular steel plate (10) for corresponding installation of negative ring segments (9) is pre-embedded on the arc cross-section structure (8). The thickness of the first annular steel plate (10) is 30±2mm and the width is 600±5mm. The negative ring segments (9) are assembled along the first annular steel plate (10). Step 4, hoisting and assembling the tunnel boring machine: Assemble the tunnel boring machine (2) in the working shaft, hoist the tunnel boring machine (2) onto the steel rail (12) of the starting base, and perform assembly and debugging; Step 5, Construction of the steel cannon support reaction system: Multiple steel cannon supports (13) are evenly distributed along the first annular steel plate (10) to replace the traditional steel reaction frame. One end of the steel cannon support (13) is welded to the arc section structure (8) through the first annular steel plate (10), and the other end is installed with a second annular steel plate (14) with a thickness of 20±2mm and a width of 500±5mm and welded to the negative ring tube segment (9); Step 6, breaking down the tunnel entrance: Use a pneumatic pick to break down the tunnel entrance (11) in layers; Step 7, Initial Advancement: The tunnel boring machine (2) advances forward.

2. The shield tunneling initiation method using the steel cannon-support reaction system as described in claim 1, replacing the steel reaction frame, is characterized in that: L-shaped steel bars are welded onto the first annular steel plate (10) for anchoring connection with the arc section structure (8). The L-shaped steel bars and the first annular steel plate (10) are connected by double-sided lap welding of 100±5mm.

3. The shield tunneling initiation method using the steel cannon-support reaction system as described in claim 2, replacing the steel reaction frame, is characterized in that: The L-shaped reinforcing bars are arranged at a 2.5° angle along the first annular steel plate (10).

4. The shield tunneling initiation method using the steel cannon support reaction system as described in claim 1, replacing the steel reaction frame, is characterized in that: The negative ring segment (9) is provided with 8-10 rings.

5. The shield tunneling initiation method using the steel cannon-support reaction system as described in claim 1, replacing the steel reaction frame, is characterized in that: The second annular steel plate (14) is connected to the negative ring segment (9) through anchor bars (1), and the anchor bars (1) are set with a length of 300±5mm and arranged in two rows in a ring.

6. The shield tunneling initiation method using the steel cannon support reaction system as described in claim 5, replacing the steel reaction frame, is characterized in that: The anchor bars (1) are arranged at a circumferential angle of 1.4° along the second annular steel plate (14).

7. The shield tunneling initiation method using the steel cannon-support reaction system as described in claim 1, replacing the steel reaction frame, is characterized in that: There are 36 steel gun supports (13), and the installation position of the steel gun support (13) and the connection seam of the negative ring tube segment (9) are offset from each other by a distance of not less than 5cm.

8. The shield tunneling initiation method using the steel cannon support reaction system as described in claim 1, replacing the steel reaction frame, is characterized in that: The portal (11) has 16 excavation areas arranged sequentially from top to bottom and from left to right. The excavation areas are excavated in at least two separate steps.

9. The shield tunneling initiation method using the steel cannon-support reaction system as described in claim 1, replacing the steel reaction frame, is characterized in that: The starting base includes a base base with a rail (12) and side bases symmetrically arranged on the left and right sides of the base base. The side bases are pre-embedded with 200×200mm H-beams (15) for installing the rail (12).

10. The shield tunneling initiation method using the steel cannon-support reaction system as described in claim 1, replacing the steel reaction frame, is characterized in that: The length of the steel gun support (13) ranges from 1993 to 2287 mm, and at least four steel gun supports (13) are provided with axial force gauges installed and evenly distributed. The axial force gauges are used to monitor the force.

Images