A new composite segment and section steel framework for a shield section

Abstract

The application provides a new composite segment and profile steel framework for a shield interval, which comprises a profile steel framework, an arc surface reinforcing rib and a construction steel bar, the profile steel framework comprises a main profile steel framework and an end profile steel framework, the number of the main profile steel framework is at least three, the main profile steel framework is a circular arc framework, and each main profile steel framework is parallel to each other; the number of the end profile steel framework is two, and each end profile steel framework is welded and fixed at the two ends of each main profile steel framework; the number of the arc surface reinforcing rib is multiple, at least two adjacent main profile steel frameworks are welded and fixed with the arc surface reinforcing rib, and the two end profile steel frameworks are welded and fixed with the arc surface reinforcing rib; the construction steel bar is used for forming bolt connection holes and / or grouting holes, and the construction steel bar is welded and fixed with the profile steel framework. The new composite segment and profile steel framework for the shield interval has the advantages of less steel bar binding, higher structural stability, easier vibration compaction and significantly improved quality.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) technology, and more specifically, to a novel composite segment and steel frame for use in TBM tunnel sections. Background Technology

[0002] In the current design and construction process of reinforced concrete tunnel segments in shield tunneling, steel bars are usually tied to form a steel cage skeleton. Then, concrete is poured in prefabricated formwork and cured in the factory. The segments can only be transported to the site for use after they have reached the required age.

[0003] The current problems faced by conventional reinforced concrete tunnel segments include: like Figure 1 and Figure 2 As shown, due to the excessively dense reinforcement of tunnel segments, especially in shield tunnel segments with greater burial depth or in special locations (such as connecting passages), large-diameter (Φ22, Φ25) steel bars are typically selected as the reinforcing steel. Additionally, reinforcing bars are placed at bolt holes, grouting holes, and other locations. Under this design, the resulting steel cage has a relatively dense reinforcement. With consistent concrete vibration, insufficient compaction can easily lead to localized strength defects in the tunnel segments. For example, the invention patent application number KR1020210117861 falls into this category, where the steel reinforcement density in the steel cage is excessively high.

[0004] Based on this design concept, conventional reinforced concrete tunnel segments can only improve their bending strength by increasing the diameter and number of reinforcing bars, and the increase in bending strength is limited.

[0005] In order to solve the above problems, people have been seeking an ideal technological solution. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a novel composite segment for shield tunnel sections that uses steel profiles as the skeleton structure to reduce the amount of reinforcing steel used, while ensuring stress stability and mitigating the problem of cumbersome reinforcing steel binding, thus providing space for the compaction of concrete.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a novel steel frame for shield tunnel sections, comprising a steel frame, arc-shaped reinforcing ribs, and structural reinforcing bars. The steel frame includes a main steel frame and end steel frames. The number of main steel frames is at least three, and the main steel frames are arc-shaped frames that conform to the curvature of the tunnel segments. Each main steel frame is parallel to the others. The number of end steel frames is two, and the two end steel frames are welded and fixed to both ends of each main steel frame, so that the steel frame forms a complete closed structure. There are multiple arc-shaped reinforcing ribs, with at least two adjacent main steel frames welded and fixed together, and two end steel frames welded and fixed together. The structural reinforcing bars are used to form bolt connection holes and / or grouting holes, and the structural reinforcing bars are welded and fixed to the steel frame.

[0008] Based on the above, the arc-shaped reinforcing rib is welded and fixed to the inner arc surface and / or outer arc surface of the steel frame.

[0009] Based on the above, the arc-shaped reinforcing bars used to connect the main steel frame are all installed near the structural reinforcing bars, and the structural reinforcing bars are welded or tied to the nearby arc-shaped reinforcing bars.

[0010] Based on the above, the cross-sections of the main steel frame and the end steel frame located on the outer side are both U-shaped channels.

[0011] Based on the above, the cross-section of the main steel frame located in the middle area is I-shaped.

[0012] Based on the above, a steel plate is welded and fixed across the outer arc surface area of ​​the steel frame, and the steel plate seals the cavity of the outer arc surface area of ​​the steel frame.

[0013] Based on the above, the steel plate and the adjacent sides of the main steel frame and the end steel frame are an integral structure.

[0014] Based on the above, there are four main steel frames, which are symmetrically distributed around the center of the segment.

[0015] A novel composite segment for shield tunneling sections includes the aforementioned novel steel frame and concrete casting body for shield tunneling sections. The concrete body is divided into three layers. The innermost layer is carbon fiber concrete, the outer surface of which does not exceed or is shallowly embedded in the lower flange of the main steel frame, and the carbon fiber joints are exposed on the outer surface of the carbon fiber concrete. The middle layer is steel fiber concrete, the inner surface of which is fused with the carbon fiber joints, the outer surface of which does not exceed or is shallowly embedded in the upper flange of the main steel frame, and the steel fibers are exposed on the outer surface of the steel fiber concrete. The outermost layer is ordinary concrete, the inner end of which is fused with the exposed steel fibers. The two outer main steel frames are located in the outermost area along the width of the concrete pouring body, and the two end steel frames are located in the outermost area along the length of the concrete pouring body. The structural reinforcement is formed in the bolt connection holes and / or grouting holes in the concrete pouring body; The steel frame, curved reinforcing bars, and structural reinforcing bars are all integrally cast inside the concrete casting body.

[0016] Based on the above, the gaps in the steel frame provide the vibration space for the concrete pouring body.

[0017] This invention has outstanding substantive features and significant progress compared to the prior art. Specifically, this invention has the following advantages: 1. By using a steel frame as the main frame and supplementing it with curved reinforcing ribs and structural reinforcing ribs to strengthen the local areas, the amount of steel bars used is greatly reduced, the frame structure is simplified, the complexity of steel bar binding is reduced, and the processing of segments is facilitated.

[0018] 2. Due to the significant reduction in the number of reinforcing bars, the vibration process after concrete pouring is easier to implement, which can effectively improve the quality of concrete segments.

[0019] 3. It makes full use of the rigidity and bending resistance of the steel profiles, and at the same time combines the good compressive strength of concrete to significantly improve the load-bearing capacity of the concrete segments.

[0020] 4. In the tunnel segment structure, to enhance the segment's strength, multiple layers of reinforced concrete are incorporated, including steel fiber reinforced concrete and carbon fiber reinforced concrete. This design addresses the relatively stringent requirements for vibration compaction in tunnel segments. If only steel fiber reinforced concrete were used, the steel fibers would gradually settle under vibration, concentrating below the formwork and failing to provide adequate support. Therefore, a layer of carbon fiber reinforced concrete is placed at the bottom. The carbon fibers in carbon fiber reinforced concrete are lightweight and possess excellent structural properties, with tensile strength far exceeding that of ordinary concrete and exceptional toughness. Supporting the inner surface not only prevents the settlement of the intermediate steel fibers but also provides additional support for the inner... The layered structure provides strong resistance to deformation, preventing cracking or damage from external forces in the tunnel shaft. The steel fiber reinforced concrete in the middle is not prone to steel fiber settlement under the support of carbon fiber concrete, and the exposed carbon fiber joints can also strengthen the connection between them. As the main component of the concrete body, steel fiber reinforced concrete provides strong structural stability and prevents the overall deformation and cracking of the tunnel segments. The outermost layer is laid with ordinary concrete for protection, and is connected to the steel fiber reinforced concrete in the middle through exposed steel fibers. Finally, together with the steel skeleton, it forms a high-strength concrete lining with good inner toughness and is not easily damaged. Attached Figure Description

[0021] Figure 1 It is the steel cage structure of concrete segments in the existing technology.

[0022] Figure 2 yes Figure 1 1-1 view.

[0023] Figure 3 This is a schematic diagram of the structure of the novel steel frame used in the shield tunnel section in Embodiment 1 of the present invention.

[0024] Figure 4 yes Figure 3 1-1 view.

[0025] Figure 5 yes Figure 4 2-2 view.

[0026] Figure 6 yes Figure 4 3-3 view.

[0027] Figure 7 This is a schematic diagram of the structure of the novel steel frame used in the shield tunnel section in Embodiment 2 of the present invention.

[0028] Figure 8 This is a structural schematic diagram of a novel steel frame used in shield tunnel sections in other embodiments of the present invention.

[0029] Figure 9 This is a schematic diagram of the concrete main structure of the novel steel frame used in the shield tunnel section in Embodiment 3 of the present invention.

[0030] In the figure: 1. Main steel frame; 2. End steel frame; 3. Curved reinforcing bar; 4. Structural reinforcing bar; 5. Bolt connection hole; 6. Grouting hole; 7. Fixing steel plate; 11. Carbon fiber concrete; 12. Steel fiber concrete; 13. Ordinary concrete. Detailed Implementation

[0031] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0032] Example 1 like Figures 3-6 As shown, a novel steel frame for shield tunneling sections includes a steel frame, curved reinforcing bars 3 and structural reinforcing bars 4. The steel frame includes a main steel frame 1 and end steel frames 2. The number of main steel frames 1 is at least three. In this embodiment, a four-frame structure is adopted, with the four main steel frames symmetrically distributed around the center of the tunnel segment.

[0033] The main steel frame 1 is an arc-shaped frame that fits the curvature of the tube segment, and each main steel frame 1 is parallel to the others; there are two end steel frames 2, which are welded and fixed to both ends of each main steel frame 1, so that the steel frame forms a complete closed structure.

[0034] The main steel frame and end steel frame located on the outer side have U-shaped cross sections, while the main steel frame located in the middle area has an I-shaped cross section.

[0035] There are multiple arc-shaped reinforcing ribs 3. At least two adjacent main steel frames 1 are welded and fixed with arc-shaped reinforcing ribs 3, and two end steel frames 4 are welded and fixed with arc-shaped reinforcing ribs 3. In this embodiment, the two ends of the length direction of two adjacent main steel frames 1 are welded and fixed with short arc-shaped reinforcing ribs, and the middle area is fixed with arc-shaped reinforcing ribs that span all main steel frames 1.

[0036] Furthermore, to highlight the effect of the arc-shaped reinforcing rib 3, arc-shaped reinforcing ribs are installed around each bolt connection hole 5 and grouting hole 6 to enhance the structural strength at this location and prevent damage under stress.

[0037] In this embodiment, the arc-shaped reinforcing rib 3 is installed on the inner and outer arc surfaces of the steel frame, thereby enclosing the steel frame into a steel-reinforcing cage structure.

[0038] The structural steel bar 4 is used to form bolt connection holes and / or grouting holes, and the structural steel bar 4 is welded and fixed to the steel frame.

[0039] The gaps in the steel frame provide a vibration space for the concrete pouring body. Due to the significant improvement in the vibration space, it is more conducive to the compaction of the concrete, and the quality is significantly improved.

[0040] In other embodiments, such as Figure 8 As shown, there are three main steel frames 1, with the middle main steel frame 1 not being centered.

[0041] Technical principle: The entire steel frame is a structure formed by the main steel frame 1 and the end steel frames 2. The structure is reinforced at the bolt holes and grouting holes by the use of structural steel bars 4 and arc-shaped reinforcing bars 3, forming a complete steel-reinforced cage structure. Due to the significant reduction in the amount of steel bars used, the structure is simplified and easier to process, while the quality stability is higher. Due to the increased pore size, it is easier to vibrate and compact the concrete after pouring, which can improve the pouring quality and ultimately improve the quality of the produced concrete segments.

[0042] Example 2 like Figure 7 As shown, the main difference between this embodiment and embodiment 1 is that: a steel plate 7 is welded and fixed across the outer arc surface area of ​​the steel frame. The steel plate 7 seals the cavity of the outer arc surface area of ​​the steel frame, making the overall structural stability of the steel frame stronger and having a sealing effect. In order to improve the structural strength, the steel plate 7 and the adjacent sides of the main steel frame 1 and the end steel frame 2 are an integral structure. They are directly processed as a whole at the beginning of processing, resulting in better structural consistency and a significant reduction in the difficulty of welding and binding.

[0043] Example 3 A novel composite segment for shield tunneling sections includes the aforementioned novel steel frame and concrete casting body for shield tunneling sections. The two outer main steel frames are located in the outermost area along the width of the concrete pouring body, and the two end steel frames are located in the outermost area along the length of the concrete pouring body. like Figure 9 As shown, the concrete body is divided into three layers. The innermost layer is carbon fiber concrete 11, the outer surface of which does not exceed or is shallowly embedded in the lower flange of the main steel frame, and the outer surface of which exposes a portion of the carbon fiber joints. The middle layer is steel fiber concrete 12, the inner surface of which is fused with the carbon fiber joints, the outer surface of which does not exceed or is shallowly embedded in the upper flange of the main steel frame, and the outer surface of which exposes a portion of the steel fibers. The outermost layer is ordinary concrete 13, the inner end of which is fused with the exposed portion of the steel fibers. The structural reinforcement is formed in the bolt connection holes and / or grouting holes in the concrete pouring body; The steel frame, curved reinforcing bars, and structural reinforcing bars are all integrally cast inside the concrete casting body.

[0044] Specific construction process: Step 1: Weld a steel frame using structural steel (wall thickness determined by the stress calculation of the tunnel segment). Note that connection bolt holes should be reserved in the tunnel segment, and holes of appropriate size should be reserved at the grouting hole location to ensure subsequent reserved holes. Step 2: Use steel bars to tie the structural steel bars at the pre-reserved bolt connection holes and grouting holes of the pipe segment, and weld them to the steel frame. In addition, add curved reinforcing bars. Step 3: The welded steel frame is installed inside the segment steel formwork, and concrete is poured and vibrated to ensure compaction. Step 4: Curing of steel-concrete composite segments. After curing, the segments are transported to the construction site for installation in the tunnel section.

[0045] 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 preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A novel composite segment for use in shield tunnel sections, characterized in that: This includes a new type of steel frame and concrete pouring structure for the shield tunnel section; The novel steel frame for shield tunnel sections includes a steel frame, arc-shaped reinforcing ribs, and structural reinforcing bars. The steel frame includes a main steel frame and end steel frames. There are at least three main steel frames, which are arc-shaped frames that conform to the curvature of the tunnel segments, and the main steel frames are parallel to each other. There are two end steel frames, which are welded and fixed to both ends of each main steel frame to form a complete closed structure. The cross-section of the main steel frame and the end steel frames on the outer side are both U-shaped channels. There are multiple arc-shaped reinforcing ribs. The two ends of two adjacent main steel frames are welded and fixed by short arc-shaped reinforcing ribs along their length. The middle area is fixed by arc-shaped reinforcing ribs that span all the main steel frames. Arc-shaped reinforcing ribs are installed around each bolt connection hole and grouting hole to enhance the structural strength at this location. The structural steel bars are used to form bolt connection holes and / or grouting holes, and the structural steel bars are welded and fixed to the steel frame. The arc-shaped reinforcing bars used to connect the main steel frame are all installed near the structural reinforcing bars, and the structural reinforcing bars are welded or tied to the nearby arc-shaped reinforcing bars. The arc-shaped reinforcing ribs are welded and fixed to the inner and outer arc surfaces of the steel frame; the steel frame is enclosed to form a steel-reinforcing cage structure; a steel plate is welded and fixed across the outer arc surface area of ​​the steel frame, and the steel plate closes the cavity of the outer arc surface area of ​​the steel frame. The concrete pouring structure consists of three layers. The innermost layer is carbon fiber concrete, with its outer surface not exceeding or shallowly embedded in the lower flange of the main steel frame, and a portion of the carbon fiber joints exposed on its outer surface. The middle layer is steel fiber concrete, with its inner surface fused to the carbon fiber joints, and its outer surface not exceeding or shallowly embedded in the upper flange of the main steel frame, and a portion of the steel fibers exposed on its outer surface. The outermost layer is ordinary concrete, with its inner end fused to the exposed portion of the steel fibers. The two outer main steel frames are located in the outermost area along the width of the concrete pouring body, and the two end steel frames are located in the outermost area along the length of the concrete pouring body. The structural reinforcement is formed in the bolt connection holes and / or grouting holes in the concrete pouring body; The steel frame, curved reinforcing bars, and structural reinforcing bars are all integrally cast inside the concrete casting body.

2. The novel composite segment for shield tunnel sections according to claim 1, characterized in that: The main steel frame located in the middle area has an I-shaped cross-section.

3. The novel composite segment for shield tunnel sections according to claim 2, characterized in that: The steel plate is an integral structure with the adjacent sides of the main steel frame and the end steel frame.

4. The novel composite segment for shield tunnel sections according to claim 1, characterized in that: The number of main steel frames is four, and the four main steel frames are symmetrically distributed around the center of the segment.

5. The novel composite segment for shield tunnel sections according to claim 1, characterized in that: The gaps in the steel frame serve as the vibration space for the concrete pouring body.

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