A reaction force backrest device for shaft shield launching and a construction method thereof

Abstract

This invention relates to the field of tunnel boring machine (TBM) construction technology, specifically disclosing a reaction backrest device for launching a vertical shaft TBM and its construction method. The device comprises a bottom load-bearing section, an upper main load-bearing section, and two compensation sections of a steel box girder structure. The upper ends of the two compensation sections are connected to both sides of the upper main load-bearing section, and the lower ends of the two compensation sections are connected to both sides of the bottom load-bearing section, forming a U-shaped box girder structure. The front side of the box girder structure is flat, and the rear side is curved, conforming to the circular wall of the vertical shaft. This invention uses a modular segmented box girder structure as the reaction backrest, consisting of a bottom load-bearing section, an upper main load-bearing section, and two side compensation sections, arranged to fit snugly against the inner wall of the circular vertical shaft lining. This solves the technical problems of traditional reaction backrests, such as damage to the lining, long construction period, uneven stress, and lack of reusability.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology, specifically to a reaction force backrest device for launching a vertical shaft TBM and its construction method. Background Technology

[0002] The shield tunneling machine (TBM) launch reaction backrest, used in conjunction with the reaction frame on the TBM, is the core temporary force-bearing structure during the TBM launch phase. It is also a key structure during the TBM launch phase, providing the reverse support force required for the initial advancement of the TBM and ensuring that the TBM can start tunneling smoothly and accurately.

[0003] Traditional reaction backrests typically employ cast-in-place reinforced concrete structures or direct supports followed by the removal of the shaft wall for rebar installation. Direct supports require the removal of the lining concrete, rebar installation, and drilling, causing irreversible damage to the main structure and posing a high risk of water damage. Circular shaft walls are curved surfaces, and traditional direct supports easily form point contacts with these curved surfaces, leading to stress concentration and potential lining cracking. Cast-in-place concrete backrests require formwork, pouring, and curing, with a construction period exceeding 28 days, severely restricting the shield tunneling launch time and causing delays. Furthermore, cast-in-place concrete is a one-time structure that needs to be demolished after launch, generating a large amount of construction waste, resulting in high costs, significant pollution, numerous high-altitude operations in the shaft, complex procedures, and high safety risks. Summary of the Invention

[0004] The purpose of this invention is to provide a reaction force backrest device for starting a vertical shaft shield tunnel and its construction method, so as to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a reaction backing device for starting a vertical shaft shield tunnel, comprising a bottom load-bearing section, an upper main load-bearing section and two compensation sections of a steel box girder structure; The upper ends of the two compensation sections are connected to both sides of the upper main load-bearing section, and the lower ends of the two compensation sections are connected to both sides of the bottom load-bearing section, so that the bottom load-bearing section, the two compensation sections and the upper main load-bearing section form a box girder structure in the shape of a "U". The rear side of the box girder structure is curved, fitting the circular wall of the shaft.

[0006] Furthermore, the bottom load-bearing section is fixed to the embedded parts of the bottom plate of the shaft by welding.

[0007] Furthermore, the gap between the rear side of the box girder structure formed by the bottom load-bearing section, the upper main load-bearing section and the two compensation sections and the lining is filled with mortar.

[0008] Furthermore, it also includes diagonal bracing; diagonal bracing is installed at each of the four corners of the U-shaped box girder structure.

[0009] This invention also provides a construction method for a reaction backrest device for starting a vertical shaft shield tunnel, comprising the following steps: Step S1: Measure and lay out the lines to determine the centerline, elevation, and installation position of the box girder structure; Step S2: Inspect the embedded parts and clean the embedded steel plate at the bottom of the shaft; Step S3: Segmented hoisting. Hoist and connect the bottom load-bearing section, the two compensation sections, and the upper main load-bearing section in sequence, and weld them together to form a U-shaped box girder structure. Step S4: Gap filling. The gap between the rear side of the box girder structure and the lining is filled with mortar in layers to achieve a dense and void-free structure. Step S5: Weld and install multiple steel pipe cross braces on the front side of the box girder structure. The multiple steel pipe cross braces are connected to the steel box girder on the tunnel boring machine.

[0010] Furthermore, step S6 is included, after the installation of the steel pipe cross brace is completed, the axis, elevation, welds and compactness of the box girder structure are checked, and the tunnel boring machine can be launched after passing the inspection.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects: A modular segmented box girder structure is used as the reaction backing, consisting of a bottom load-bearing section, an upper main load-bearing section, and two side compensation sections, which are arranged to fit snugly against the inner wall of the circular shaft lining. The box girder structure sits directly on the embedded parts of the shaft bottom plate and is welded and fixed without removing the lining, installing reinforcement bars, or damaging the waterproof layer. The reaction frame and the box girder structure are connected by steel pipe cross bracing to form a complete force-bearing system. This invention solves the technical problems of traditional reaction backings, such as damage to the lining, long construction period, uneven stress, and lack of reusability. It has the advantages of zero damage to the main structure, rapid installation, high rigidity, uniform force transmission, and recyclability, and is suitable for the initial construction of various types of circular shaft shield tunnels with completed lining. Attached Figure Description

[0012] Figure 1 This is a front view of the present invention.

[0013] Figure 2 This is a top view of the upper main load-bearing section.

[0014] Figure 3 for Figure 1 Disassembly diagram.

[0015] Figure 4 This is a top view of the bottom load-bearing section.

[0016] Figure 5 This is a front view of the bottom load-bearing section.

[0017] Figure 6 This is a side view of the bottom load-bearing section.

[0018] Figure 7This is a side cross-sectional view of the present invention in a vertical shaft.

[0019] Figure 8 This is a top view of the invention in a vertical shaft.

[0020] Figure 9 This is an installation diagram of the present invention.

[0021] Figure 10 for Figure 1 A schematic diagram of the installation of steel pipe cross braces.

[0022] The meanings of the labels in the diagram are as follows: 1-Upper main load-bearing section, 2-Bottom load-bearing section, 3-Compensation section, 4-Diagonal brace, 5-Vertical shaft, 6-Steel pipe horizontal brace, 7-Reaction frame. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, so as to provide a better understanding of the concept of the present invention, the technical problem solved, the technical features constituting the technical solution, and the technical effects brought about.

[0024] like Figures 1-6 As shown, a reaction backrest device for starting a vertical shaft shield tunnel includes a bottom load-bearing section 2, an upper main load-bearing section 1, and two compensation sections 3 of a steel box girder structure. The upper ends of the two compensation sections 3 are respectively connected to both sides of the upper main load-bearing section 1, and the lower ends of the two compensation sections 3 are respectively connected to both sides of the bottom load-bearing section 2, so that the bottom load-bearing section 2, the two compensation sections 3, and the upper main load-bearing section 1 form a U-shaped box girder structure. The rear side of the box girder structure is curved and fits the circular wall of the vertical shaft 5.

[0025] Traditional reaction backrests are typically constructed using cast-in-place reinforced concrete structures or direct supports. The disadvantages of cast-in-place concrete reaction backrests include long construction periods and difficulty in dismantling. This invention utilizes a modular, segmented box girder structure made of steel box girder material as the reaction backrest. It consists of a bottom load-bearing section 2, an upper main load-bearing section 1, and two compensation sections 3, and is integrally fitted to the inner wall of the circular shaft 5 lining. The box girder structure sits directly on the embedded parts of the shaft 5 bottom plate and is welded and fixed, solving the technical problems of traditional reaction backrests such as lining damage, long construction periods, uneven stress distribution, and lack of reusability. The technical problems with direct supports are that traditional direct supports easily form point contacts, leading to stress concentration and lining cracking. The advantages of this invention are: no lining removal, no rebar installation, no damage to the waterproof layer, zero damage to the main structure, rapid installation, high rigidity, uniform force transmission, and recyclability. It is suitable for the initial construction of shield tunneling in various types of already lined circular shafts 5.

[0026] Furthermore, the bottom load-bearing section 2 is fixed to the pre-embedded parts of the bottom plate of the shaft 5 by welding.

[0027] Furthermore, the gap between the rear side of the box girder structure formed by the bottom load-bearing section 2, the upper main load-bearing section 1, and the two compensation sections 3 and the lining is filled with mortar. The mortar filling between the box girder structure and the lining forms a surface contact force transmission; the reaction frame 7 and the steel box girder are connected by steel pipe cross braces 6 to form a complete force-bearing system.

[0028] Furthermore, it also includes diagonal braces 4, which are installed at the four corners of the U-shaped box girder structure. The diagonal braces 4 further increase the connection strength between the bottom load-bearing section 2, the upper main load-bearing section 1, and the two side compensation sections 3.

[0029] like Figures 7-10 As shown, the present invention also provides a construction method for a reaction backrest device for starting a vertical shaft shield tunnel, comprising the following steps: Step S1: Measure and lay out the lines to determine the centerline, elevation, and installation position of the box girder structure; Step S2: Inspect the embedded parts and clean the embedded steel plate at the bottom of shaft 5; Step S3: Segmented hoisting. Hoist and connect the bottom load-bearing section 2, the two compensation sections 3, and the upper main load-bearing section 1 in sequence, and form a box girder structure with the bottom load-bearing section 2, the two compensation sections 3, and the upper main load-bearing section 1 in the direction of welding. Step S4: Gap filling. The gap between the rear side of the box girder structure and the lining is filled with mortar in layers to achieve a dense and void-free structure. Step S5: Weld and install multiple steel pipe cross braces 6 on the front side of the box girder structure. The multiple steel pipe cross braces 6 are connected to the steel box girder on the tunnel boring machine.

[0030] Furthermore, step S6 is also included. After the installation of the steel pipe cross brace 6 is completed, the axis, elevation, welds and compactness of the box girder structure are checked. If they pass the test, the tunnel boring machine can be launched.

[0031] The reaction backrest adopts a four-section modular box girder structure, including a bottom load-bearing section 2, an upper main load-bearing section 1, and two side compensation sections 3, which are arranged to fit the inner wall of the circular shaft 5 lining. The box girder structure sits on the embedded steel plate of the bottom plate of the shaft 5 and is welded and fixed to the embedded parts without chiseling, rebar installation, or damage to the lining and waterproof layer. The gap between the steel box girder and the lining is filled with mortar to achieve uniform force transmission through surface contact. The reaction force 7 is connected to the steel box girder by a seamless steel pipe cross brace 6 to form a complete force-bearing system. This invention solves the problems of traditional reaction backrests that damage the lining, have a long construction period, uneven stress, and are not reusable. It has the advantages of zero damage to the main structure, rapid installation, high rigidity, recyclability, and safety and reliability, and is suitable for shield tunneling launching projects in various shafts 5 that have already been lined.

[0032] The terms "connection" and "fixing" appearing in the description of this invention can refer to fixed connection, processing and forming, welding, or mechanical connection. The specific meaning of the above terms in this invention should be understood according to the specific circumstances.

[0033] In the description of this invention, the terms "center," "upper," "lower," "horizontal," "inner," and "outer," etc., are used only to indicate the orientation or positional relationship for the convenience of describing this invention and to simplify the description, and do not indicate or imply a specific orientation that the device or element referred to must have, and therefore should not be construed as a limitation of this invention.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reaction force backrest device for starting a vertical shaft shield tunnel, characterized in that, It includes the bottom load-bearing section (2), the upper main load-bearing section (1), and two compensation sections (3) of the steel box girder structure. The upper ends of the two compensation sections (3) are respectively connected to the two sides of the upper main load-bearing section (1), and the lower ends of the two compensation sections (3) are respectively connected to the two sides of the bottom load-bearing section (2), so that the bottom load-bearing section (2), the two compensation sections (3) and the upper main load-bearing section (1) form a box girder structure in the shape of a square. The rear side of the box girder structure is curved, fitting the circular wall of the vertical shaft (5).

2. The reaction backrest device for starting a vertical shaft shield tunnel as described in claim 1, characterized in that, The bottom load-bearing section (2) is fixed to the bottom plate of the shaft (5) by welding.

3. The reaction force backrest device for starting a vertical shaft shield tunnel as described in claim 1, characterized in that, The gap between the rear side of the box girder structure formed by the bottom load-bearing section (2), the upper main load-bearing section (1) and the two compensation sections (3) and the lining is filled with mortar.

4. The reaction backrest device for starting a vertical shaft shield tunnel as described in claim 1, characterized in that, It also includes diagonal bracing (4), with diagonal bracing (4) installed at the four corners of the square box girder structure.

5. A construction method for a reaction backrest device for starting a vertical shaft shield tunnel, based on claims 1-4, characterized in that, Includes the following steps: Step S1: Measure and lay out the lines to determine the centerline, elevation, and installation position of the box girder structure; Step S2, inspect the embedded parts and clean the embedded steel plate at the bottom of the shaft (5); Step S3, segmented hoisting, hoisting and connecting the bottom load-bearing section (2), the two compensation sections (3) and the upper main load-bearing section (1) in sequence, and forming a box girder structure with the bottom load-bearing section (2), the two compensation sections (3) and the upper main load-bearing section (1) through welding direction; Step S4: Gap filling. The gap between the rear side of the box girder structure and the lining is filled with mortar in layers to achieve a dense and void-free structure. Step S5: Weld and install multiple steel pipe cross braces (6) on the front side of the box girder structure. The multiple steel pipe cross braces (6) are connected to the steel box girder on the tunnel boring machine.

6. The construction method of a reaction backrest device for starting a vertical shaft shield tunnel according to claim 5, characterized in that, It also includes step S6, after the installation of the steel pipe cross brace (6) is completed, the axis, elevation, weld and density of the box girder structure are checked, and the shield tunnel can be launched after passing the test.

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