Reinforcing structure and reinforcing method for convex and concave tenons of duct pieces in prefabrication stage

Abstract

The invention discloses a reinforcing structure and a reinforcing method for a convex tenon and a concave tenon of a pipe piece in a prefabrication stage. The reinforcing structure comprises a reinforcement cage, crossed ribs, spiral ribs and an anti-cracking net. Wherein the reinforcement cage and the concrete are poured together to serve as a main structure for improving the overall bearing capacity of the duct piece; the crossed ribs are connected with the reinforcement cage and used for improving the bearing capacity of concrete at the tenons of the duct pieces; the spiral bars are connected with the crossed bars, and the spiral bars and the crossed bars jointly improve the bearing capacity of concrete at the tenon and the tenon of the duct piece; and the anti-cracking net is used for wrapping the concrete and gathering the concrete at the concave tenons and the convex tenons into a whole so as to improve the bearing capacity of the convex tenons and the concave tenons of the duct pieces. According to the method, a combination mode of the anti-cracking net and the steel bars is adopted to perform targeted reinforcement on weak stress parts, namely the convex-concave tenons, when shield tunnel segments are staggered and subjected to elliptic change, so that not only can the diseases such as cracking, cracking and water leakage of the convex-concave tenons in the tunnel construction and operation process be effectively relieved, but also the reinforcement mode is low in manufacturing cost, and the construction is convenient.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel shield, and in particular relates to a reinforcement structure and a reinforcement method for convex and concave tenons of a prefabrication stage pipe segment. Background Art

[0002] With the advancement of my country's urbanization process, the construction of infrastructure such as subways and water tunnels, which are mainly based on the shield method, has been vigorously developed. From the current situation of shield tunnel on-site construction and operation, the segments of shield tunnels in soft soil layers are more prone to adverse conditions such as inter-ring misalignment and intra-ring elliptical deformation due to the disturbance of surrounding loads. At the same time, it will further cause cracking, damage and water leakage in the segment joints. The segment joints are usually the weak points of the shield tunnel bearing system, and the mortise and tenon of the tenon segment is also the primary load-bearing component when the segment misalignment and elliptical deformation occur, and the mortise and tenon are very easy to be damaged.

[0003] The traditional solution is to use steel plates, aramid cloth, etc. to reinforce the joints of the segments when cracks, misalignment, water leakage, etc. occur. At the same time, the measure to enhance the bearing capacity of the segments from the prefabrication stage is still mainly steel fiber concrete, but it has not been widely used due to the high cost of steel fiber concrete, the difficulty of local reinforcement, and the chloride ions in the marine strata will accelerate the erosion of steel fibers after the segments are damaged.

[0004] In the current segment design, mortises and tenons are widely used as important shear-resistant components of circumferential joints. However, in mortises and tenons, only cross bars are usually used as the only load-bearing structure other than plain concrete, and in mortises, only spiral bars are used as the only load-bearing structure other than plain concrete. Considering that the segment joint is the weak point in the load-bearing system, the design with few bars is not conducive to preventing the occurrence of diseases at the segment joint. Therefore, improving the resistance performance of the mortises and tenons of the segment is crucial to improving the overall load-bearing mode of the segment joint and preventing the segment joint from being damaged. Summary of the invention

[0005] The purpose of the present invention is to provide a reinforcement structure and method for the convex and concave tenons of the prefabricated segment. The reinforcement structure includes a steel cage, cross bars, spiral bars and an anti-crack net; wherein the steel cage is cast together with the concrete as the main structure to improve the overall bearing capacity of the segment; the cross bars are connected to the steel cage to improve the bearing capacity of the concrete at the convex and concave tenons of the segment; the spiral bars are connected to the cross bars, and together with the cross bars, they improve the bearing capacity of the concrete at the concave and concave tenons of the segment; the anti-crack net is used to wrap the concrete and gather the concrete at the concave and concave tenons as a whole to improve the bearing capacity of the convex and concave tenons of the segment. The present invention adopts a combination of anti-crack nets and steel bars to carry out targeted reinforcement of the weak stress-bearing parts of the shield tunnel segment when the segment is misaligned and elliptical, namely the "convex and concave tenons". Not only can it effectively alleviate the cracking, rupture and water leakage of the convex and concave tenons during the construction and operation of the tunnel; moreover, the reinforcement method has low cost and convenient construction, and ensures the economy of the reinforcement measures while improving the shear and bending resistance of the segment joints.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a reinforcement structure for the convex and concave tenons of a pipe segment in the prefabrication stage. The reinforcement structure comprises:

[0008] The steel cages at the convex and concave tenons are cast together with the concrete, serving as the main structure to enhance the overall bearing capacity of the segment.

[0009] The cross reinforcement of the tenon is used to improve the bearing capacity of the concrete at the tenon of the segment;

[0010] The spiral reinforcement of the tenon and the spiral reinforcement of the tenon are used to improve the bearing capacity of the concrete at the tenon and tenon of the pipe segment respectively;

[0011] The anti-cracking nets for reinforcing the convex tenons and the anti-cracking nets for reinforcing the concave tenons are used to gather the concrete at the convex tenons and concave tenons as a whole, thereby improving the bearing capacity of the convex tenons and concave tenons of the pipe segment.

[0012] Furthermore, the cross bars, spiral bars, anti-cracking nets and steel cages at the convex tenon are overlapped to form a steel resistance skeleton of the convex tenon to reinforce the convex tenon; the spiral bars, anti-cracking nets and steel cages at the concave tenon are overlapped to form a steel resistance skeleton of the concave tenon to reinforce the concave tenon.

[0013] Optionally, the steel reinforcement force-resisting skeleton of the tenon comprises:

[0014] steel cage at the tenon;

[0015] Cross bars reinforcing the tenon, connected to the reinforcement cage at the tenon and at least partially located within the tenon;

[0016] a spiral rib of the reinforcing tenon connected to the cross rib of the reinforcing tenon and at least partially located within the tenon;

[0017] The anti-cracking net of the reinforcing tenon is connected to the cross ribs of the reinforcing tenon and has a protrusion adapted to the tenon, wherein the protrusion is located outside the cross ribs of the reinforcing tenon and the spiral ribs of the reinforcing tenon.

[0018] Optionally, the steel reinforcement resistance skeleton of the tenon is cast together with the concrete at the tenon; and the anti-cracking net for reinforcing the tenon is parallel to the outer wall of the concrete at the tenon.

[0019] Optionally, the anti-cracking net of the reinforcing tenon is overlapped with the cross bars of the reinforcing tenon through short steel bars.

[0020] Optionally, the steel reinforcement force-resisting skeleton of the tenon comprises:

[0021] Steel reinforcement cage at the mortise and tenon joint;

[0022] The spiral reinforcement for reinforcing the tenon is connected to the steel cage at the tenon;

[0023] The anti-cracking net of the reinforced tenon is connected to the spiral ribs of the reinforced tenon and is located on the outside of the spiral ribs of the reinforced tenon; the anti-cracking net of the reinforced tenon has a recessed portion adapted to the tenon, and the recessed portion is at least partially embedded in the spiral ribs of the reinforced tenon.

[0024] Optionally, the steel reinforcement resistance skeleton of the tenon is cast together with the concrete at the tenon; and the anti-cracking net for reinforcing the convex tenon is parallel to the outer wall of the concrete at the tenon.

[0025] Optionally, the anti-cracking net of the reinforcing tenon is overlapped with the spiral reinforcement of the reinforcing tenon through short steel bars.

[0026] The present invention also provides a method for reinforcing the convex and concave tenons of a pipe segment in the prefabrication stage. The method comprises:

[0027] S10, a steel reinforcement frame overlapping the tenon to strengthen the tenon;

[0028] S20, overlap the steel reinforcement resistance frame of the tenon to strengthen the tenon.

[0029] Optionally, the steel reinforcement force-resisting frame of the overlapping tenon in step S10 to reinforce the tenon includes:

[0030] S11, the steel cage at the welded tenon serves as the load-bearing frame;

[0031] S12, connecting the cross ribs of the reinforcing tenon to the steel cage at the tenon, and making the cross ribs of the reinforcing tenon at least partially located inside the tenon;

[0032] S13, connecting the spiral ribs of the reinforcing tenon to the cross ribs of the reinforcing tenon, and making the spiral ribs of the reinforcing tenon at least partially located inside the tenon;

[0033] S14, connecting the anti-cracking net of the reinforcing tenon with the cross ribs of the reinforcing tenon, and making the raised portion of the anti-cracking net of the reinforcing tenon located outside the cross ribs of the reinforcing tenon and the spiral ribs of the reinforcing tenon.

[0034] Optionally, the steel bar resistance frame of the overlapping tenon to reinforce the tenon in step S20 includes:

[0035] S21, the steel cage at the welded tenon serves as the load-bearing framework;

[0036] S22, connecting the spiral reinforcement of the tenon to the steel cage at the tenon;

[0037] S23, connecting the anti-cracking net of the reinforcing tenon with the spiral rib of the reinforcing tenon, and making the anti-cracking net of the reinforcing tenon be located on the outside of the spiral rib of the reinforcing tenon, and making the recessed part of the spiral rib of the reinforcing tenon at least partially embedded in the spiral rib of the reinforcing tenon.

[0038] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0039] (1) Stronger local reinforcement effect: Compared with the unreinforced case, the combined reinforcement method of anti-crack mesh and steel bars adopted in the present invention can provide stronger local reinforcement effect at weak parts of shield tunnel segments, such as convex and concave joints. In particular, in the case of inter-ring misalignment and intra-ring elliptical deformation, this reinforcement method can significantly improve the shear and bending resistance and effectively prevent structural damage.

[0040] (2) Reduce crack expansion: The combined reinforcement method of anti-crack mesh and steel bars used in the present invention can effectively inhibit and reduce crack expansion, improving the overall durability and safety of the structure. Moreover, compared with the case without reinforcement, this reinforcement method can control cracks at an early stage and prevent them from further developing, thereby ensuring the long-term stability of the tunnel.

[0041] (3) Convenient construction: Compared with fiber concrete which is inconvenient for local pouring, the combined reinforcement method of anti-cracking mesh and steel bars used in the present invention is more convenient to construct. The anti-cracking mesh and steel bars can be locally installed during the prefabrication stage or on-site installation stage, reducing the construction difficulty and time. It is especially suitable for engineering projects that need to be processed quickly.

[0042] (4) High cost-effectiveness: The reinforcement method of the present invention using anti-cracking mesh combined with steel bars is low in cost, and the materials are easily available and low in cost. Compared with the fiber concrete reinforcement method that requires a large amount of materials and complex construction processes, the reinforcement method of the present invention not only reduces the material cost, but also reduces the labor and time costs, thereby improving the overall economic benefits.

[0043] (5) High flexibility: The combined reinforcement method of anti-crack mesh and steel bars used in the present invention has high flexibility and can be adjusted and optimized according to specific engineering requirements. Moreover, compared with the fiber concrete reinforcement method, this method is easier to carry out local reinforcement treatment in different construction environments and conditions, and has stronger adaptability.

[0044] (6) Easy maintenance: During the operation of the tunnel, if the local reinforcement part needs to be maintained or repaired, the combination of anti-crack mesh and steel bars used in the present invention is easier to operate. In addition, compared with the fiber concrete reinforcement method, the combined reinforcement solution of anti-crack mesh and steel bars used in the present invention is easier to maintain, reducing the maintenance cost and time during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the convex and concave tenon types of the pipe segment in the embodiment of the present invention; Figure 1 (a) is a runway-type distributed convex and concave tenon, Figure 1 (b) is a point-shaped distributed convex and concave tenon. Figure 1 (c) through-type mortise and tenon;

[0046] Figure 2 is the actual part of the segment to be reinforced in the embodiment of the present invention, Figure 2 In (a), A is a dot-shaped tenon. Figure 2 In (b), B is a dot-shaped tenon;

[0047] Figure 3 It is an axonometric view of the dot-shaped convex-concave tenon reinforcement structure in an embodiment of the present invention;

[0048] Figure 4 A top view of a dot-shaped convex-concave tenon reinforcement structure according to an embodiment of the present invention;

[0049] Figure 5 It is a partial schematic diagram of a dot-shaped convex-concave tenon reinforcement structure in an embodiment of the present invention;

[0050] Figure 6 is a schematic diagram of a dot-shaped tenon reinforcement structure in an embodiment of the present invention, wherein Figure 6 (a) is the axonometric view of the point-shaped tenon reinforcement structure. Figure 6 (b) is a top view of the dot-shaped tenon reinforcement structure;

[0051] Figure 7is a schematic diagram of a dot-shaped tenon reinforcement member according to an embodiment of the present invention; Figure 7 (a) is a schematic diagram of the steel cage at the dot-shaped tenon. Figure 7 (b) is a schematic diagram of the cross reinforcement of the dot-shaped tenon. Figure 7 (c) is a schematic diagram of the spiral reinforcement for reinforcing the dot-shaped tenon. Figure 7 (d) is a schematic diagram of the anti-cracking net for reinforcing the dot-shaped tenon. Figure 7 (e) is a schematic diagram of the concrete at the dot-shaped tenon;

[0052] Figure 8 Schematic diagram of the reinforcement process of the dot-shaped tenon in the embodiment of the present invention;

[0053] Fig. 9 is a schematic diagram of a dot-shaped tenon-and-mortise reinforcement structure according to an embodiment of the present invention, wherein Fig. 9 (a) is the axonometric view of the dot-shaped mortise and tenon reinforcement structure. Fig. 9 (b) is a top view of the dot-shaped tenon-and-mortise reinforcement structure;

[0054] Fig.10 is a schematic diagram of a dot-shaped tenon-mortise reinforcement member according to an embodiment of the present invention; Fig.10 (a) is a schematic diagram of the steel cage at the dot-shaped tenon. Fig.10 (b) is a schematic diagram of the spiral reinforcement for reinforcing the dot-shaped tenon. Fig.10 (c) is a schematic diagram of the anti-crack net for reinforcing the dot-shaped tenon. Fig.10 (d) is a schematic diagram of the concrete at the dot-shaped tenon;

[0055] Fig.11 Schematic diagram of the reinforcement process of the dot-shaped tenon in an embodiment of the present invention;

[0056] Fig.12 The DAMAGEC cloud diagram of the compression damage of the tenon concrete corresponding to different reinforcement methods in the embodiment of the present invention, wherein the sub Fig.12 (a) is model ①, Fig.12 (b) is model ②, Fig.12 (c) is model ③;

[0057] Fig.13 is the concrete damage volume corresponding to different damage levels of the tenon segments corresponding to different reinforcement methods in the embodiment of the present invention, where Fig.13 (a) is a bar chart showing the damage volume corresponding to different DAMAGEC levels of compressive damage of the tenon segment concrete. Fig.13 (b) is a bar chart showing the damage volume corresponding to different DAMAGET levels of tensile damage to the concrete of the tenon segment.

[0058] Description of reference numerals:

[0059] A. Point-shaped tenon; B. Point-shaped tenon; 1. Steel cage at the point-shaped tenon; 2. Cross bars reinforcing the point-shaped tenon; 3. Spiral bars reinforcing the point-shaped tenon; 4. Anti-cracking net reinforcing the point-shaped tenon; 5. Concrete at the point-shaped tenon; 6. Steel cage at the point-shaped tenon; 7. Spiral bars reinforcing the point-shaped tenon; 8. Anti-cracking net reinforcing the point-shaped tenon; 9. Concrete at the point-shaped tenon. DETAILED DESCRIPTION

[0060] In order to make the purpose, features and beneficial effects of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described below are only used to explain the present invention, rather than to limit the present invention.

[0061] In addition, for the convenience of description, only the parts related to the present invention are shown in the drawings instead of all structures. In addition, the same or similar reference numerals may be used in the drawings to refer to the same or similar components in different embodiments.

[0062] The embodiments of the present invention provide a reinforcement structure and a reinforcement method for the mortise and tenon joints of a pipe segment in a prefabrication stage.

[0063] Specifically, the reinforcement structure includes a steel cage, cross bars, spiral bars, anti-cracking nets at the tenon and a steel cage, spiral bars, anti-cracking nets at the tenon; wherein, the cross bars, spiral bars, anti-cracking nets at the tenon are overlapped with the steel cage to form a steel resistance skeleton of the tenon to reinforce the tenon; the spiral bars, anti-cracking nets at the tenon are overlapped with the steel cage to form a steel resistance skeleton of the tenon to reinforce the tenon.

[0064] In some embodiments, the steel resistance frame of the tenon can also be called the reinforcement structure of the tenon of the pipe segment in the prefabrication stage; the steel resistance frame of the tenon can also be called the reinforcement structure of the tenon of the pipe segment in the prefabrication stage.

[0065] When designing the shield tunnel segments, the mortise and tenon are located at the two ends of a single segment along the longitudinal direction of the tunnel. During the casting process of the segments, the mortise and tenon of each segment are reinforced with a combination of "anti-crack mesh and steel bars". The segments can be assembled at the construction site later.

[0066] Reference Figure 1 There are many types of mortise and tenon joints in the pipe segments, for example, Figure 1 (a) shows the racetrack-type distributed convex and concave tenons, Figure 1 (b) shows the dot-shaped distributed convex and concave tenons, Figure 1 (c) The through-type mortise and tenon shown.

[0067] Figure 2 (a) Point-shaped tenon A and Figure 2(b) The dot-shaped tenons and tenons B respectively show the actual tenons and tenons to be reinforced at the parts of the pipe segments in the embodiment of the present invention.

[0068] Reference Figures 3 to 11 The embodiment of the present invention takes the point-shaped distributed convex and concave tenons as an example to illustrate the reinforcement structure and reinforcement method of the convex and concave tenons of the prefabrication stage pipe segment provided by the present invention.

[0069] Specifically, the reinforcement structure of the mortise and tenon of the prefabrication stage pipe segment provided by the embodiment of the present invention includes a steel bar resistance frame of the point-shaped mortise and tenon and a steel bar resistance frame of the point-shaped mortise and tenon.

[0070] In some embodiments, the steel reinforcement resistance skeleton of the point-shaped tenon includes a steel cage 1 at the point-shaped tenon, cross bars 2 for reinforcing the point-shaped tenon, spiral bars 3 for reinforcing the point-shaped tenon, and an anti-cracking net 4 for reinforcing the point-shaped tenon.

[0071] In a specific implementation, the steel cage 1 at the point-shaped tenon is suitable as the main supporting structure; the cross ribs 2 for reinforcing the point-shaped tenon are connected to the steel cage 1 at the point-shaped tenon, for example, welded together, and are at least partially located in the point-shaped tenon; the spiral ribs 3 for reinforcing the point-shaped tenon are connected to the cross ribs 2 for reinforcing the point-shaped tenon, for example, welded together, and are at least partially located in the point-shaped tenon; the anti-cracking net 4 for reinforcing the point-shaped tenon is connected to the cross ribs 2 for reinforcing the point-shaped tenon, for example, welded together, and has a protrusion adapted to the point-shaped tenon, and the protrusion is located on the outside of the cross ribs 2 for reinforcing the point-shaped tenon and the spiral ribs 3 for reinforcing the point-shaped tenon.

[0072] When overlapping the steel bar force-resisting frame of the point-shaped tenon, the requirement that the steel bar with a smaller diameter and the anti-cracking mesh be fixed to the steel bar with a larger diameter before pouring concrete is met.

[0073] In a specific implementation, the steel reinforcement force-resisting skeleton of the point-shaped tenon is poured together with the concrete 5 at the point-shaped tenon.

[0074] In some embodiments, the anti-crack net 4 for reinforcing the dot-shaped tenon is parallel to the outer wall of the concrete 5 at the dot-shaped tenon. In this way, the crack expansion caused by stress concentration can be prevented, and the crack resistance of the concrete can be improved. Moreover, the parallel arrangement of the anti-crack net 4 for reinforcing the dot-shaped tenon facilitates the construction personnel to accurately locate and install the anti-crack net 4 for reinforcing the dot-shaped tenon during the construction process, thereby ensuring the construction quality.

[0075] In some embodiments, the anti-cracking net 4 of the reinforced point-shaped tenon is overlapped with the cross reinforcement 2 of the reinforced point-shaped tenon through short steel bars.

[0076] In some embodiments, considering that the size of the tenon is relatively small relative to the thickness of the pipe segment, and a protective layer of a certain thickness needs to be provided between the anti-crack net and the concrete outer wall, the steel bars of the anti-crack net 4 reinforcing the point-shaped tenon are thinner than the steel bars of the steel cage 1 at the point-shaped tenon. At this time, the anti-crack net can ensure the integrity of the outer wall of the pipe segment while holding the concrete.

[0077] During actual reinforcement, appropriate parameters can be selected according to the size of the pipe segment and the design drawings to improve the resistance performance of the convex and concave tenons of the pipe segment. For example, for a pipe segment with a thickness of 400mm, the steel bar diameter, hole spacing, and protective layer thickness between the anti-crack net 4 reinforcing the point-shaped tenon and the concrete outer wall can refer to the following parameters. That is, the diameter of the steel bar of the anti-crack net 4 reinforcing the point-shaped tenon can be 1-3mm; the hole spacing of the anti-crack net 4 reinforcing the point-shaped tenon can be 2-4cm; the protective layer thickness between the anti-crack net 4 reinforcing the point-shaped tenon and the concrete outer wall can be about 5mm.

[0078] In some embodiments, the steel reinforcement resistance skeleton of the point-shaped tenon includes a steel reinforcement cage 6 at the point-shaped tenon, a spiral rib 7 for reinforcing the point-shaped tenon, and an anti-cracking net 8 for reinforcing the point-shaped tenon.

[0079] In a specific implementation, the steel cage 6 at the point-shaped tenon is suitable as the main supporting structure; the spiral ribs 7 for reinforcing the point-shaped tenon are connected to the steel cage 6 at the point-shaped tenon, for example, welded together; the anti-cracking net 8 for reinforcing the point-shaped tenon is connected to the spiral ribs 7 for reinforcing the point-shaped tenon, for example, welded together, and is located on the outside of the spiral ribs 7 for reinforcing the point-shaped tenon; the anti-cracking net 8 for reinforcing the point-shaped tenon also has a recessed portion adapted to the point-shaped tenon, and the recessed portion is at least partially embedded in the spiral ribs 7 for reinforcing the point-shaped tenon.

[0080] When overlapping the steel bar resistance frame of the point-shaped tenon, the requirement that the smaller diameter steel bar and the anti-cracking mesh are fixed to the larger diameter steel bar before pouring concrete is met.

[0081] In some embodiments, the steel reinforcement resistance skeleton of the point-shaped tenon is cast together with the concrete 9 at the point-shaped tenon.

[0082] In some embodiments, the anti-crack net 8 reinforcing the dot-shaped tenon is parallel to the outer wall of the concrete 9 at the dot-shaped tenon. In this way, the crack expansion caused by stress concentration can be prevented and the crack resistance of the concrete can be improved. Moreover, the parallel arrangement of the anti-crack nets facilitates the construction workers to accurately locate and install the anti-crack nets during the construction process, thereby ensuring the construction quality.

[0083] In some embodiments, the anti-cracking mesh 8 for reinforcing the point-shaped tenon is overlapped with the spiral reinforcement 7 for reinforcing the point-shaped tenon through short steel bars.

[0084] In some embodiments, considering that the size of the convex and concave tenons is relatively small relative to the thickness of the pipe segment, and a protective layer of a certain thickness needs to be provided between the anti-crack net and the concrete outer wall, the steel bars of the anti-crack net 8 reinforcing the dot-shaped concave tenons are thinner than the steel bars of the steel cage 6 at the dot-shaped concave tenons. At this time, the anti-crack net can ensure the integrity of the outer wall of the pipe segment while holding the concrete.

[0085] During actual reinforcement, appropriate parameters can be selected according to the size of the pipe segment and the design drawings to improve the resistance performance of the convex and concave tenons of the pipe segment. For example, for a pipe segment with a thickness of 400mm, the steel bar diameter, hole spacing, and protective layer thickness between the anti-crack net 8 and the concrete outer wall of the reinforced point-shaped tenon can refer to the following parameters. That is, the diameter of the steel bar of the anti-crack net 8 reinforcing the point-shaped tenon can be 1-3mm; the hole spacing of the anti-crack net 8 reinforcing the point-shaped tenon can be 2-4cm; the protective layer thickness between the anti-crack net 8 reinforcing the point-shaped tenon and the concrete outer wall can be about 5mm.

[0086] In order to better understand the reinforcement structure of the mortise and tenon of the prefabricated segment provided by the embodiment of the present invention, the following is an explanation in combination with the position and connection relationship of the steel bar resistance skeleton in the mortise and tenon during welding.

[0087] (1) Steel cage: The steel cage should be placed accurately at the position specified in the design drawings to ensure that it can fully play its bearing role after being poured together with the concrete. The main bars and stirrups of the steel cage should be welded firmly to ensure the integrity and stability of the structure. The spacing between welding points should meet the design requirements.

[0088] (2) Cross reinforcement: The cross reinforcement should be precisely positioned at the tenon to ensure that the bearing capacity of the concrete in this area can be effectively improved. The welding between the cross reinforcement and the steel cage should be firm, and the welding points should be evenly distributed to avoid stress concentration. Attention should be paid to the welding quality during welding to prevent false welding and leaking welding.

[0089] (3) Spiral reinforcement: Spiral reinforcement should be wrapped around the tenons and mortises according to the design requirements to ensure that it works together with the cross reinforcement or steel cage to improve the bearing capacity of these parts. The welding between the spiral reinforcement and the cross reinforcement or steel cage should be strong, and the number of welding points should be sufficient and the spacing should be reasonable to ensure the overall stability and bearing capacity of the structure.

[0090] (4) Anti-crack net: The anti-crack net should be kept at a certain distance from the outer wall of the concrete, that is, there should be a protective layer outside the anti-crack net, especially at the tenons and mortises, to ensure that it can effectively prevent concrete cracking and enhance its integrity. The connection points of the anti-crack net should be evenly distributed, and the grid spacing should meet the design requirements.

[0091] Precautions during welding:

[0092] (1) Welding quality: All welding points should comply with relevant welding standards and quality requirements to avoid welding defects such as cracks, pores, slag inclusions, etc.

[0093] (2) Welding sequence: The welding sequence should be carried out according to the design requirements. Usually, it should start from the main reinforcement, followed by the welding of cross reinforcement, spiral reinforcement and anti-cracking mesh to ensure the stability of each part during the welding process.

[0094] Furthermore, an embodiment of the present invention also provides a method for reinforcing the dot-shaped convex and concave tenons of pipe segments in the prefabrication stage.

[0095] Specifically, the reinforcement method includes:

[0096] S10, overlapping the steel bar resistance frame of the point-shaped tenon to reinforce the point-shaped tenon;

[0097] S20, overlapping the steel bar resistance frame of the point-shaped tenon and groove to reinforce the point-shaped tenon and groove.

[0098] In some embodiments, the step S10 of overlapping the steel reinforcement force-resisting frame of the point-shaped tenon to reinforce the point-shaped tenon includes:

[0099] S11, welding the steel cage 1 at the point-shaped tenon as a load-bearing frame, such as Figure 8 (a)

[0100] S12, connecting the cross ribs 2 of the reinforced point-shaped tenon to the steel cage 1 at the point-shaped tenon, for example, by welding, and making the cross ribs 2 of the reinforced point-shaped tenon at least partially located in the point-shaped tenon, such as Figure 8 As shown in (b), the “red solid dots” represent the welding points between the cross bars 2 reinforcing the dot-shaped tenon and the steel cage 1 at the dot-shaped tenon;

[0101] S13, connecting the spiral rib 3 of the reinforced point-shaped tenon with the cross rib 2 of the reinforced point-shaped tenon, for example, by welding, and making the spiral rib 3 of the reinforced point-shaped tenon at least partially located in the point-shaped tenon, such as Figure 8 As shown in (c), the “blue solid dots” represent the welding points between the spiral ribs 3 of the reinforced point-shaped tenon and the cross ribs 2 of the reinforced point-shaped tenon;

[0102] S14, connecting the anti-cracking net 4 of the reinforced point-shaped tenon to the cross rib 2 of the reinforced point-shaped tenon, and making the raised portion of the anti-cracking net 4 of the reinforced point-shaped tenon located outside the cross rib 2 of the reinforced point-shaped tenon and the spiral rib 3 of the reinforced point-shaped tenon, as shown in FIG. Figure 8 As shown in (d), the "yellow solid dots" represent the welding points between the anti-cracking net 4 for reinforcing the point-shaped tenon and the cross ribs 2 for reinforcing the point-shaped tenon.

[0103] When the anti-cracking net 4 of the reinforced point-shaped tenon and the cross reinforcement 2 of the reinforced point-shaped tenon cannot be directly overlapped, short steel bars are used to connect the anti-cracking net 4 of the reinforced point-shaped tenon and the cross reinforcement 2 of the reinforced point-shaped tenon. Figure 8 (d) and Figure 8The “short yellow line” between the two “solid yellow dots” of the welding points in (e) represents the short steel bar.

[0104] In some embodiments, the reinforcement method further comprises:

[0105] S15, pouring concrete 5 to complete the targeted reinforcement of the segment tenon, such as Figure 8 (e) as shown.

[0106] When overlapping the steel bar force-resisting frame of the point-shaped tenon, the requirement that the steel bar with a smaller diameter and the anti-cracking mesh be fixed to the steel bar with a larger diameter before pouring concrete is met.

[0107] In some embodiments, the step S20 of overlapping the steel bar resistance framework of the point-shaped tenon to reinforce the point-shaped tenon includes:

[0108] S21, welding the steel cage 6 at the dot-shaped tenon as a load-bearing frame, such as Fig.11 (a)

[0109] S22, connecting the spiral ribs 7 for reinforcing the dot-shaped tenon with the steel cage 6 at the dot-shaped tenon, for example, by welding. Fig.11 As shown in (b), the “red solid dots” represent the welding points between the spiral reinforcement 7 of the reinforced tenon and the steel cage 6 of the reinforced tenon;

[0110] S23, connecting the anti-cracking net 8 of the reinforced dot-shaped tenon and the spiral rib 7 of the reinforced dot-shaped tenon, for example, by welding them together, and making the anti-cracking net 8 of the reinforced dot-shaped tenon be located outside the spiral rib 7 of the reinforced dot-shaped tenon, and making the concave part of the spiral rib 7 of the reinforced dot-shaped tenon at least partially embedded in the spiral rib 7 of the reinforced dot-shaped tenon, such as Fig.11 As shown in (c), the “blue solid dots” represent the welding points between the anti-cracking net 8 and the spiral ribs 7.

[0111] When the anti-cracking net 8 of the reinforced tenon and the spiral reinforcement 7 of the reinforced tenon cannot be directly overlapped, short steel bars are used to connect the anti-cracking net 8 of the reinforced tenon and the spiral reinforcement 7 of the reinforced tenon. Fig.11 (c) and Fig.11 (d) The “short blue line” between the two “solid blue dots” of the welding point represents the short steel bar.

[0112] In some embodiments, the reinforcement method further comprises:

[0113] S24, pouring concrete 9 at the tenon to complete the targeted reinforcement of the tenon of the pipe segment, such as Fig.11 (d) as shown.

[0114] When overlapping the steel bar resistance frame of the point-shaped tenon, the requirement that the smaller diameter steel bar and the anti-cracking mesh are fixed to the larger diameter steel bar before pouring concrete is met.

[0115] In the embodiment of the present invention, the above-mentioned technical scheme is adopted to reinforce the mortise and tenon joints of the segments in the prefabrication stage, which not only can improve the shear and bending resistance of the shield tunnel segments, but also has significant advantages in terms of construction convenience, cost-effectiveness, maintenance and adaptability, especially in cases where local reinforcement is required.

[0116] Furthermore, the embodiment of the present invention also conducts a damage performance test on the reinforced structure of the mortise and tenon joints of the pipe segments in the prefabrication stage.

[0117] Specifically, the embodiment of the present invention uses the finite element method to set the same material parameters and shear load to establish finite element models corresponding to different reinforcement schemes. Among them, the concrete grade is C55, the concrete plastic damage CDP (Concrete Damaged Plasticity) constitutive model is adopted, the elastic modulus is 35.5GPa, the Poisson's ratio is 0.2, and the density is 2.4t / m 3 The steel cage is made of φ25 steel bars, the cross bars and spiral bars are both φ6 steel bars, and the anti-cracking mesh is φ2 steel bars. Their elastic modulus is 210GPa, Poisson's ratio is 0.3, and density is 7.85t / m 3 , the shear load is 250kPa.

[0118] Model ①: Only the cross reinforcement 2 for reinforcing the point-shaped tenon is used to reinforce the point-shaped tenon;

[0119] Model ②: The tenon is reinforced by the cross ribs 2 for reinforcing the point-shaped convex tenon and the spiral ribs 3 for reinforcing the point-shaped convex tenon; at the same time, the point-shaped concave tenon is reinforced by the spiral ribs 7 for reinforcing the point-shaped concave tenon;

[0120] Model ③: The point-shaped tenons are reinforced by cross ribs 2, spiral ribs 3 and anti-cracking nets 4; at the same time, the point-shaped concave tenons are reinforced by spiral ribs 7 and anti-cracking nets 8.

[0121] Take the concrete compression DAMAGEC damage of the tenon side segment as an example. Fig.12 As shown, it can be intuitively seen that the concrete damage volume obtained based on the analysis of model ③ is the smallest. Therefore, compared with the cases of only using cross reinforcement or cross reinforcement and spiral reinforcement, namely model ① and model ②, the technical solution provided by the present invention, namely model ③, can effectively reduce the concrete damage volume.

[0122] The compressive damage DAMAGEC of the concrete of the tenon side segment is similar to that of the tenon side segment, and will not be described here.

[0123] Fig.13(a) shows the volume of concrete compressive damage DAMAGEC corresponding to the three models at different damage levels. Overall, model ③ performs best at all damage levels, especially at high damage levels (0.9-1.0), the damage volume is significantly lower than that of model ① and model ②, which indicates that model ③ is the most effective in limiting segment damage. Fig.13 (b) shows the volume corresponding to the concrete tensile damage DAMAGET of the three models at different damage levels. Fig.13 (a) is similar to that of model ③, and the damage volume of model ③ is lower at each damage level. Especially at high damage level (0.9-1.0), the damage volume of model ③ is significantly smaller than that of model ① and model ②, showing better anti-damage performance.

[0124] Furthermore, the damage volumes corresponding to the damage levels of 0.9-1.0 are statistically listed in Table 1. Table 1 shows the maximum misalignment, maximum principal stress of steel bars, volume of concrete compressive damage DAMAGEC (0.9-1.0), and volume of concrete tensile damage DAMAGET (0.9-1.0) under the same loading conditions, i.e., 250 kPa pressure, for the three reinforcement cases.

[0125] Table 1 Misalignment and tenon mechanical parameters under three reinforcement conditions under the same loading conditions

[0126]

[0127] As shown in Table 1, under the action of 250 kPa pressure, model ③, i.e. the technical solution provided by the present invention, has the best effect in limiting the misalignment of the pipe segments, and the concrete damage volume is also the smallest, while the principal stress of the steel bar is the largest. It can be seen that the steel bar bears part of the load, thereby limiting the damage of the concrete. The compressive damage and tensile damage volumes corresponding to the damage level 0.9-1.0 are reduced by 55.38% and 40.40% respectively. At the same time, the difference in the amount of misalignment is not very large, but there is also a trend of reduction.

[0128] Combined with the above performance tests, we can know that:

[0129] (1) By optimizing the reinforcement, the steel bars can bear part of the load, reducing the stress on the concrete, thereby improving the shear and bending resistance of the segment joints.

[0130] (2) By properly arranging the anti-crack mesh and fine steel bars, the development of concrete cracks can be effectively controlled to prevent stress concentration and local cracking. This helps maintain the integrity and sealing of the structure and reduce the occurrence of water leakage. The anti-crack mesh of the fine steel bars performs well in improving the crack resistance of concrete. At the same time, during the construction process, the fine steel bars are easier to bend and shape, which facilitates the accurate arrangement of construction personnel, further ensuring the durability and reliability of the structure. The analysis results also show that although the amount of misalignment is not much different, there is also a trend of reduction, indicating that optimizing the steel bar configuration can help limit misalignment and improve joint stability.

[0131] (3) Through these optimization measures, the shear and bending resistance of the segment joints can be significantly improved, and the problems of cracking, rupture and water leakage that may occur during tunnel construction and operation can be effectively alleviated.

[0132] It is understandable that the types of mortise and tenon that can be reinforced by the technical solution provided by the present invention are not limited to Figures 3 to 11 The dot-shaped convex-concave tenon specifically shown in the embodiment may also include a racetrack-type distributed convex-concave tenon and a through-type convex-concave tenon. During the implementation process, it is only necessary to adjust the shape of the anti-crack net to make the shape of the anti-crack net adapt to the shape of the racetrack-type distributed convex-concave tenon or the through-type convex-concave tenon.

[0133] Furthermore, the technical solution provided by the present invention can also be used to reinforce other similar components with shear or bending resistance.

[0134] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the present disclosure, even when only a single embodiment is described with respect to specific features. The feature examples provided in the present disclosure are intended to be illustrative rather than limiting, unless otherwise stated. In specific implementations, the technical features of one or more dependent claims may be combined with the technical features of the independent claims, based on actual needs and where technically feasible, and the technical features from the corresponding independent claims may be combined in any appropriate manner rather than just by the specific combinations listed in the claims.

[0135] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A reinforcement structure for the convex and concave tenons of a prefabricated segment, characterized in that: It includes a steel cage, cross bars, spiral bars, anti-cracking net at the convex tenon and a steel cage, spiral bars, anti-cracking net at the concave tenon; wherein, the cross bars, spiral bars, anti-cracking net at the convex tenon are overlapped with the steel cage to form a steel resistance skeleton of the convex tenon to reinforce the convex tenon; the spiral bars, anti-cracking net at the concave tenon are overlapped with the steel cage to form a steel resistance skeleton of the concave tenon to reinforce the concave tenon.

2. The reinforcement structure according to claim 1, characterized in that: The steel reinforcement force-resisting skeleton of the tenon comprises: steel cage at the tenon; Cross bars reinforcing the tenon, connected to the reinforcement cage at the tenon and at least partially located within the tenon; a spiral rib of the reinforcing tenon connected to the cross rib of the reinforcing tenon and at least partially located within the tenon; The anti-cracking net of the reinforcing tenon is connected to the cross ribs of the reinforcing tenon and has a protrusion adapted to the tenon, wherein the protrusion is located outside the cross ribs of the reinforcing tenon and the spiral ribs of the reinforcing tenon.

3. The reinforcement structure according to claim 2, characterized in that: The steel reinforcement force-resisting skeleton of the tenon is cast together with the concrete at the tenon; the anti-cracking net for reinforcing the tenon is parallel to the outer wall of the concrete at the tenon.

4. The reinforcement structure according to claim 2, characterized in that: The anti-cracking net of the reinforcing tenon is overlapped with the cross reinforcement of the reinforcing tenon through short steel bars.

5. The reinforcement structure according to claim 1, characterized in that: The steel reinforcement force-resisting framework of the tenon and mortise comprises: Steel cage at the mortise and tenon joint; The spiral reinforcement for reinforcing the tenon is connected to the steel cage at the tenon; The anti-cracking net of the reinforced tenon is connected to the spiral ribs of the reinforced tenon and is located on the outside of the spiral ribs of the reinforced tenon; the anti-cracking net of the reinforced tenon has a recessed portion adapted to the tenon, and the recessed portion is at least partially embedded in the spiral ribs of the reinforced tenon.

6. The reinforcement structure according to claim 5, characterized in that: The steel reinforcement force-resisting skeleton of the tenon is cast together with the concrete at the tenon; the anti-cracking net for reinforcing the tenon is parallel to the outer wall of the concrete at the tenon.

7. The reinforcement structure according to claim 5, characterized in that: The anti-cracking net of the reinforcing tenon is overlapped with the spiral reinforcement of the reinforcing tenon through short steel bars.

8. A method for reinforcing the convex and concave tenons of pipe segments in the prefabrication stage, characterized in that: S10, a steel reinforcement frame overlapping the tenon to strengthen the tenon; S20, overlap the steel reinforcement resistance frame of the tenon to strengthen the tenon.

9. The reinforcement method according to claim 8, characterized in that: The steel reinforcement force-resisting frame of the overlapping tenon in step S10 to reinforce the tenon includes: S11, the steel cage at the welded tenon serves as the load-bearing frame; S12, connecting the cross ribs of the reinforcing tenon to the steel cage at the tenon, and making the cross ribs of the reinforcing tenon at least partially located inside the tenon; S13, connecting the spiral ribs of the reinforcing tenon to the cross ribs of the reinforcing tenon, and making the spiral ribs of the reinforcing tenon at least partially located inside the tenon; S14, connecting the anti-cracking net of the reinforcing tenon with the cross ribs of the reinforcing tenon, and making the raised portion of the anti-cracking net of the reinforcing tenon located outside the cross ribs of the reinforcing tenon and the spiral ribs of the reinforcing tenon.

10. The reinforcement method according to claim 8, characterized in that: The steel reinforcement resistance frame of the overlapping tenon in step S20 to reinforce the tenon includes: S21, the steel cage at the welded tenon serves as the load-bearing framework; S22, connecting the spiral reinforcement of the tenon to the steel cage at the tenon; S23, connecting the anti-cracking net of the reinforcing tenon with the spiral rib of the reinforcing tenon, and making the anti-cracking net of the reinforcing tenon be located on the outside of the spiral rib of the reinforcing tenon, and making the recessed part of the spiral rib of the reinforcing tenon at least partially embedded in the spiral rib of the reinforcing tenon.

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