Reinforcing structure of segment mortise in precast stage
By setting a combined reinforcement structure of anti-crack mesh and steel bars at the convex and concave joints of shield tunnel segments, the problems of inter-ring misalignment and intra-ring elliptic deformation caused by the convex and concave joints of shield tunnel segments being easily disturbed by surrounding loads are solved, improving shear and bending resistance and reducing construction and maintenance costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TONGJI UNIV
- Filing Date
- 2024-12-01
- Publication Date
- 2026-06-26
AI Technical Summary
In existing technologies, the interlocking joints of shield tunnel segments are easily affected by surrounding loads, leading to misalignment between rings and elliptic deformation within the rings. Furthermore, traditional reinforcement measures such as steel fiber reinforced concrete are costly and difficult to implement locally, and cannot effectively prevent defects such as cracking and water leakage.
A combination of crack-resistant mesh and steel reinforcement is used for reinforcement. Steel cages, cross bars, spiral bars and crack-resistant mesh are set at the protruding and concave tenons to form a steel reinforcement resistance skeleton, which is then reinforced by welding and pouring concrete.
It significantly improves the shear and bending resistance of the tongue and groove joints of shield tunnel segments, reduces crack propagation, lowers construction and maintenance costs, and is highly adaptable, making it suitable for rapid project handling.
Smart Images
Figure CN224413641U_ABST
Abstract
Description
[0001] This utility model is a divisional application for the following case:
[0002] Application Number: 202422943076.X
[0003] Application date: 2024-12-01
[0004] Invention Title: Reinforcement Structure for Tenons and Corrugated Tenons of Precast Segments Technical Field
[0005] This utility model belongs to the field of tunnel shield technology, specifically relating to a reinforcement structure for the tenon joint of precast tunnel segments. Background Technology
[0006] With the advancement of urbanization in my country, the construction of infrastructure such as subways and water conveyance tunnels, primarily using the shield tunneling method, has been vigorously developed. From the current status of shield tunnel construction and operation, shield tunnel segments in soft soil strata are more prone to adverse conditions such as inter-ring misalignment and intra-ring elliptic deformation due to disturbances from surrounding loads. Furthermore, this can further lead to defects such as cracking, damage, and water leakage at the segment joints. Segment joints are typically the weakest points in the load-bearing system of shield tunnels, and the tenon joints of tenoned segments are the primary load-bearing components when segment misalignment and elliptic deformation occur; these tenons are extremely susceptible to damage.
[0007] Traditional solutions involve reinforcing the joints of tunnel segments with steel plates and aramid fabrics after defects such as cracking, misalignment, and leakage occur. Meanwhile, steel fiber reinforced concrete remains the primary method for enhancing the load-bearing capacity of tunnel segments during the prefabrication stage. However, its widespread application is limited due to issues such as high cost, difficulty in implementing localized reinforcement, and the accelerated erosion of steel fibers by chloride ions in marine strata after segment damage.
[0008] In current tunnel segment design, tenon joints are widely used as important shear-resistant components in circumferential joints. However, the tenon typically uses only cross reinforcement as the sole load-bearing structure outside the plain concrete, while the tenon uses only spiral reinforcement. Considering that the tunnel segment joint is inherently a weak point in the load-bearing system, this under-reinforced design is detrimental to preventing joint defects. Therefore, improving the resistance performance of the tenon joint is crucial for improving the overall load-bearing mechanism of the tunnel segment joint and preventing joint failure. Utility Model Content
[0009] The purpose of this invention is to provide a reinforcement structure for the tenon joint of precast tunnel segments. The reinforcement structure includes: a reinforcing cage at the tenon; a spiral reinforcement bar connected to the reinforcing cage at the tenon; a crack-resistant mesh connected to the spiral reinforcement bar and located outside the spiral reinforcement bar; the crack-resistant mesh also has a recessed portion adapted to the tenon, at least partially embedded within the spiral reinforcement bar. This invention uses a combination of crack-resistant mesh and reinforcing steel to specifically reinforce the weak points of the "protruding and concave tenon" in shield tunnel segments when they are misaligned or elliptical. This not only effectively alleviates cracking, rupture, and water leakage of the protruding and concave tenon joint during tunnel construction and operation, but also offers low cost and convenient construction, ensuring the economic efficiency of the reinforcement measures while improving the shear and bending resistance of the segment joints.
[0010] To achieve the above objectives, this utility model provides the following technical solution:
[0011] One aspect of this utility model is to provide a reinforcement structure for the tenon of a precast segment, comprising: a reinforcing cage at the tenon; cross reinforcement bars for reinforcing the tenon, connected to the reinforcing cage at the tenon and at least partially located inside the tenon; spiral reinforcement bars for reinforcing the tenon, connected to the cross reinforcement bars for reinforcing the tenon and at least partially located inside the tenon; and crack-resistant mesh for reinforcing the tenon, connected to the cross reinforcement bars for reinforcing the tenon and having a protrusion adapted to the tenon, the protrusion being located outside the cross reinforcement bars and the spiral reinforcement bars for reinforcing the tenon.
[0012] Optionally, the reinforcing structure is cast together with the concrete at the tenon.
[0013] Optionally, the anti-crack mesh of the reinforcing tenon is parallel to the outer wall of the concrete at the tenon.
[0014] Optionally, the anti-crack mesh of the reinforcing tenon is lapped with the cross bars of the reinforcing tenon by short steel bars.
[0015] Optionally, the segment tenon may include a dot tenon, a racetrack-shaped tenon, or a through tenon.
[0016] Another aspect of this utility model is to provide a reinforcement structure for the tenon of a precast segment, comprising: a steel cage at the tenon; a spiral reinforcement for reinforcing the tenon, connected to the steel cage at the tenon; a crack-resistant mesh for reinforcing the tenon, connected to the spiral reinforcement for reinforcing the tenon and located outside the spiral reinforcement for reinforcing the tenon; the crack-resistant mesh for reinforcing the tenon has a recessed portion adapted to the tenon, the recessed portion being at least partially embedded in the spiral reinforcement for reinforcing the tenon.
[0017] Optionally, the reinforcing structure is cast together with the concrete at the tenon joint.
[0018] Optionally, the anti-crack mesh of the reinforcing tenon is parallel to the outer wall of the concrete at the tenon.
[0019] Optionally, the anti-crack mesh of the reinforcing tenon is connected to the spiral reinforcement of the reinforcing tenon by short steel bars.
[0020] Optionally, the segment tenon includes a dot-shaped tenon, a racetrack-shaped tenon, or a through tenon.
[0021] Compared with the prior art, the technical solution of this utility model has at least the following beneficial effects:
[0022] (1) Stronger local reinforcement effect: Compared with the unreinforced situation, the combination of crack-resistant mesh and steel bars used in this utility model can provide a stronger local reinforcement effect in the weak parts of the shield tunnel segments, such as the tenon joints. Especially in the case of inter-ring misalignment and intra-ring elliptic deformation, this reinforcement method can significantly improve shear and bending resistance and effectively prevent structural damage.
[0023] (2) Reducing crack propagation: The combination of crack-resistant mesh and steel reinforcement in this invention can effectively suppress and reduce crack propagation, improving the overall durability and safety of the structure. Moreover, compared to the unreinforced situation, this reinforcement method can control cracks when they appear in the early stages, preventing them from developing further and thus ensuring the long-term stability of the tunnel.
[0024] (3) Convenient construction: Compared with fiber concrete, which is not convenient for local pouring, the combination of crack-resistant mesh and steel reinforcement in this utility model is more convenient to construct. The crack-resistant mesh and steel reinforcement can be locally installed in the prefabrication stage or on-site installation stage, reducing construction difficulty and time, and is especially suitable for engineering projects that require rapid processing.
[0025] (4) High cost-effectiveness: The reinforcement method of this utility model using anti-crack mesh combined with steel bars is low-cost, and the materials are readily available and inexpensive. Compared with fiber concrete reinforcement, which requires a large amount of materials and complex construction processes, the reinforcement method of this utility model not only reduces material costs, but also reduces labor and time costs, thereby improving overall economic efficiency.
[0026] (5) High flexibility: The combination of crack-resistant mesh and steel reinforcement in this utility model has high flexibility and can be adjusted and optimized according to specific engineering needs. Moreover, compared with fiber reinforced concrete reinforcement, this method is easier to carry out local reinforcement treatment in different construction environments and conditions, and has stronger adaptability.
[0027] (6) Easy maintenance: During tunnel operation, if maintenance or repair of local reinforced parts is required, the combination of anti-crack mesh and steel bars adopted in this utility model is easier to operate. Moreover, compared with fiber concrete reinforcement, the combination of anti-crack mesh and steel bars adopted in this utility model is easier to maintain, reducing maintenance costs and time during operation. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the tenon and tenon type of the pipe segment in an embodiment of this utility model; wherein, the sub- Figure 1 (a) is a runway-shaped distributed tenon and mortise joint, and the sub-tenon... Figure 1 (b) is a dotted distributed tenon and mortise joint, the child Figure 1 (c) is a through tenon joint;
[0029] Figure 2 This refers to the actual part of the pipe segment to be reinforced in this embodiment of the invention. Figure 2 In (a), A is a dot-shaped tenon. Figure 2 In (b), B is a dotted tenon;
[0030] Figure 3 This is an axonometric view of the dotted tenon and mortise reinforcement structure in an embodiment of this utility model;
[0031] Figure 4 This is a top view of the dotted tenon and mortise reinforcement structure in an embodiment of this utility model;
[0032] Figure 5 This is a partial schematic diagram of the dotted convex and concave tenon reinforcement structure in an embodiment of this utility model;
[0033] Figure 6 This is a schematic diagram of the dotted tenon reinforcement structure in an embodiment of this utility model, wherein, the sub- Figure 6 (a) is an axonometric view of the dotted tenon reinforcement structure. Figure 6 (b) is a top view of the dotted tenon reinforcement structure;
[0034] Figure 7 This is a schematic diagram of the dotted tenon reinforcement component in an embodiment of this utility model; wherein, the sub- Figure 7 Image (a) is a schematic diagram of the reinforcing cage at the dotted tenon joint. Figure 7 (b) is a schematic diagram of the intersecting ribs for reinforcing the dotted tenon. Figure 7 (c) is a schematic diagram of the spiral reinforcement for reinforcing the dotted tenon. Figure 7 Image (d) is a schematic diagram of a crack-prevention mesh reinforced with dotted tenons. Figure 7 (e) is a schematic diagram of the concrete at the dotted tenon joint;
[0035] Figure 8This is a schematic diagram of the reinforcement process of the dotted tenon in an embodiment of this utility model;
[0036] Figure 9 This is a schematic diagram of the dotted tenon reinforcement structure in an embodiment of this utility model, wherein, the sub- Figure 9 (a) is an axonometric view of the dotted tenon reinforcement structure. Figure 9 (b) is a top view of the dotted tenon reinforcement structure;
[0037] Figure 10 This is a schematic diagram of the dotted tenon reinforcement component in an embodiment of this utility model; wherein, the sub- Figure 10 (a) is a schematic diagram of the reinforcing cage at the dotted tenon joint. Figure 10 (b) is a schematic diagram of the spiral reinforcement for reinforcing the dotted tenon. Figure 10 Image (c) is a schematic diagram of a crack-prevention mesh reinforced with dotted tenons. Figure 10 (d) is a schematic diagram of the concrete at the dotted tenon joint;
[0038] Figure 11 This is a schematic diagram of the reinforcement process of the dotted tenon in an embodiment of this utility model;
[0039] Figure 12 This is a DAMAGEC cloud map of the compressive damage of the tenon concrete corresponding to different reinforcement methods in the embodiments of this utility model, wherein, the sub Figure 12 In the middle (a), model ① is shown, and the sub-model ② is shown. Figure 12 (b) represents model ②, sub-model ②. Figure 12 (c) represents model ③;
[0040] Figure 13 This refers to the concrete damage volume corresponding to different damage levels of the tenon segments under different reinforcement methods in this embodiment of the invention, wherein the sub- Figure 13 (a) is a bar chart showing the damage volume of the tenoned pipe segment concrete corresponding to different DAMAGE C levels of compressive damage. Figure 13 (b) is a bar chart showing the damage volume of the tenoned pipe segment concrete under different tensile damage levels according to the DAMAGET classification.
[0041] Explanation of reference numerals in the attached figures:
[0042] A. Point-shaped protruding tenon; B. Point-shaped concave tenon; 1. Reinforcing cage at the point-shaped protruding tenon; 2. Cross reinforcement of the point-shaped protruding tenon; 3. Spiral reinforcement of the point-shaped protruding tenon; 4. Crack-resistant mesh for the point-shaped protruding tenon; 5. Concrete at the point-shaped protruding tenon; 6. Reinforcing cage at the point-shaped concave tenon; 7. Spiral reinforcement of the point-shaped concave tenon; 8. Crack-resistant mesh for the point-shaped concave tenon; 9. Concrete at the point-shaped concave tenon. Detailed Implementation
[0043] To make the objectives, features, and beneficial effects of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described below are merely for explaining this utility model and are not intended to limit it.
[0044] Furthermore, for ease of description, only the parts relevant to this invention are shown in the accompanying drawings, not the entire structure. Also, the same or similar reference numerals may be used in the drawings to refer to the same or similar components in different embodiments.
[0045] This utility model embodiment provides a reinforcement structure for the prefabrication stage segment tenon and segment recess tenon.
[0046] Specifically, the reinforcement structure includes a steel cage, cross bars, spiral bars, and crack-resistant mesh at the protruding tenon and a steel cage, spiral bars, and crack-resistant mesh at the recessed tenon; wherein, the cross bars, spiral bars, and crack-resistant mesh at the protruding tenon overlap with the steel cage to form a steel reinforcement resistance skeleton for the protruding tenon to reinforce the protruding tenon; the spiral bars and crack-resistant mesh at the recessed tenon overlap with the steel cage to form a steel reinforcement resistance skeleton for the recessed tenon to reinforce the recessed tenon.
[0047] In some embodiments, the reinforcing steel reinforcement skeleton of the tenon can also be referred to as the reinforcing structure of the tenon of the precast segment; the reinforcing steel reinforcement skeleton of the tenon can also be referred to as the reinforcing structure of the tenon of the precast segment.
[0048] When designing shield tunnel segments, the tenon and the countersunk tenon are located at both ends of a single segment along the longitudinal direction of the tunnel. During the segment casting process, the tenon and countersunk tenon of each segment are reinforced by a combination of "crack-resistant mesh and steel bars". The segments can then be assembled on the construction site.
[0049] Reference Figure 1 There are various types of tongue and groove joints for pipe segments, for example, Figure 1 The runway-shaped distributed tenon and mortise joint shown in (a) is Figure 1 The dotted distributed tenon and mortise joints shown in (b) are Figure 1 The through tenon shown in (c) is a tenon with a convex and concave shape.
[0050] Figure 2 (a) Dot-shaped tenon A and Figure 2 The dotted tenon B in the middle (b) shows the actual tenon and tenon to be reinforced in the pipe segment in the embodiment of this utility model.
[0051] Reference Figures 3 to 11 This utility model embodiment uses a dotted distributed tenon and mortise joint as an example to illustrate the reinforcement structure and reinforcement method of the tenon and mortise joint for precast segments provided by this utility model.
[0052] Specifically, the reinforcement structure of the precast segment convex and concave tenon provided in this embodiment of the present invention includes a steel reinforcement resistance skeleton with dotted convex tenons and a steel reinforcement resistance skeleton with dotted concave tenons.
[0053] In some embodiments, the reinforcing steel reinforcement framework of the dotted tenon includes a steel cage 1 at the dotted tenon, cross bars 2 for reinforcing the dotted tenon, spiral bars 3 for reinforcing the dotted tenon, and crack-resistant mesh 4 for reinforcing the dotted tenon.
[0054] In specific implementation, the reinforcing cage 1 at the dotted tenon is suitable as the main support structure; the cross reinforcement 2 of the dotted tenon is connected to the reinforcing cage 1 at the dotted tenon by means of welding, and is at least partially located inside the dotted tenon; the spiral reinforcement 3 of the dotted tenon is connected to the cross reinforcement 2 of the dotted tenon by means of welding, and is at least partially located inside the dotted tenon; the crack-resistant mesh 4 of the dotted tenon is connected to the cross reinforcement 2 of the dotted tenon by means of welding, and has a protrusion adapted to the dotted tenon, the protrusion being located outside the cross reinforcement 2 and the spiral reinforcement 3 of the dotted tenon.
[0055] When constructing a reinforcing steel reinforcement cage with overlapping dovetail joints, the requirement is met that smaller diameter reinforcing bars and anti-crack mesh be fixed to larger diameter reinforcing bars before pouring concrete.
[0056] In practice, the steel reinforcement skeleton of the dotted tenon is poured together with the concrete 5 at the dotted tenon.
[0057] In some embodiments, the anti-crack mesh 4 reinforcing the dotted tenons is parallel to the outer wall of the concrete 5 at the dotted tenons. This prevents crack propagation due to stress concentration and improves the crack resistance of the concrete. Furthermore, the parallel arrangement of the anti-crack mesh 4 reinforcing the dotted tenons facilitates accurate positioning and installation by construction personnel during construction, ensuring construction quality.
[0058] In some embodiments, the anti-crack mesh 4 for reinforcing the dotted tenon is lapped with the cross bar 2 for reinforcing the dotted tenon by short steel bars.
[0059] In some embodiments, considering that the dimensions of the tenon and mortise are relatively small compared to the thickness of the segment, and that a protective layer of a certain thickness needs to be provided between the crack-resistant mesh and the outer wall of the concrete, the reinforcing bars of the crack-resistant mesh 4 reinforcing the dotted tenons are thinner than the reinforcing bars of the reinforcing cage 1 at the dotted tenons. In this case, the crack-resistant mesh can ensure the integrity of the outer wall of the segment while holding the concrete.
[0060] In actual reinforcement, appropriate parameters can be selected based on the segment dimensions and design drawings to improve the resistance performance at the tenon and vent joints. For example, for a 400mm thick segment, the diameter of the reinforcing bars, the hole spacing, and the thickness of the protective layer between the reinforcing mesh 4 and the concrete outer wall can be referenced to the following parameters: Specifically, the diameter of the reinforcing bars in the reinforcing mesh 4 can be 1-3mm; the hole spacing can be 2-4cm; and the thickness of the protective layer between the reinforcing mesh 4 and the concrete outer wall can be approximately 5mm.
[0061] In some embodiments, the reinforcing steel skeleton of the dotted tenon includes a steel cage 6 at the dotted tenon, a spiral bar 7 for reinforcing the dotted tenon, and a crack-resistant mesh 8 for reinforcing the dotted tenon.
[0062] In specific implementation, the reinforcing cage 6 at the dotted tenon is suitable as the main support structure; the spiral reinforcement 7 for reinforcing the dotted tenon is connected to the reinforcing cage 6 at the dotted tenon, for example, by welding; the anti-crack mesh 8 for reinforcing the dotted tenon is connected to the spiral reinforcement 7 for reinforcing the dotted tenon, for example, by welding, and is located outside the spiral reinforcement 7 for reinforcing the dotted tenon; the anti-crack mesh 8 for reinforcing the dotted tenon also has a recessed portion adapted to the dotted tenon, and the recessed portion is at least partially embedded in the spiral reinforcement 7 for reinforcing the dotted tenon.
[0063] When constructing a reinforcing steel reinforcement framework with overlapping dovetail joints, the requirement is met that smaller diameter reinforcing bars and anti-crack mesh be fixed to larger diameter reinforcing bars before pouring concrete.
[0064] In some embodiments, the reinforcing steel skeleton of the dotted tenon is cast together with the concrete 9 at the dotted tenon.
[0065] In some embodiments, the anti-crack mesh 8 reinforcing the dotted tenons is parallel to the outer wall of the concrete 9 at the dotted tenons. This prevents crack propagation due to stress concentration and improves the crack resistance of the concrete. Furthermore, the parallel arrangement of the anti-crack mesh facilitates accurate positioning and installation by construction personnel during construction, ensuring construction quality.
[0066] In some embodiments, the anti-crack mesh 8 that reinforces the dotted tenon is overlapped with the spiral reinforcement 7 that reinforces the dotted tenon by short steel bars.
[0067] In some embodiments, considering that the dimensions of the tenon and mortise are relatively small compared to the thickness of the segment, and that a protective layer of a certain thickness needs to be provided between the crack-resistant mesh and the outer wall of the concrete, the reinforcing bars of the crack-resistant mesh 8 reinforcing the dotted tenons are thinner than the reinforcing bars of the reinforcing cage 6 at the dotted tenons. In this case, the crack-resistant mesh can ensure the integrity of the outer wall of the segment while holding the concrete.
[0068] In actual reinforcement, appropriate parameters can be selected based on the segment dimensions and design drawings to improve the resistance performance of the segment's tongue and groove joints. For example, for a 400mm thick segment, the diameter of the reinforcing bars, the hole spacing, and the thickness of the protective layer between the reinforcing mesh 8 and the concrete outer wall can be referenced to the following parameters: Specifically, the diameter of the reinforcing bars in the reinforcing mesh 8 can be 1-3mm; the hole spacing can be 2-4cm; and the thickness of the protective layer between the reinforcing mesh 8 and the concrete outer wall can be approximately 5mm.
[0069] To better understand the reinforcement structure of the precast segment mortise and tenon joint provided in this embodiment of the present invention, the following explanation is based on the position and connection relationship of the steel reinforcement resistance skeleton in the mortise and tenon joint during welding.
[0070] (1) Reinforcing cage: The reinforcing cage should be accurately placed in the position specified in the design drawings to ensure that it can fully perform its load-bearing function after being poured together with the concrete. The main bars and stirrups of the reinforcing cage should be firmly welded together to ensure the integrity and stability of the structure. The spacing between the welding points should meet the design requirements.
[0071] (2) Cross reinforcement: Cross reinforcement should be precisely positioned at the tenon to ensure effective improvement of the load-bearing capacity of the concrete in that area. The welding between the cross reinforcement and the reinforcing cage should be firm, and the weld points should be evenly distributed to avoid stress concentration. During welding, attention should be paid to the welding quality to prevent incomplete welds and missed welds.
[0072] (3) Spiral reinforcement: The spiral reinforcement should be wrapped around the tenon and mortise according to the design requirements to ensure that it works together with the cross reinforcement or steel cage to enhance the load-bearing capacity of these parts. The welding between the spiral reinforcement and the cross reinforcement or steel cage should be firm, and the number of welding points should be sufficient and the spacing should be reasonable to ensure the overall stability and load-bearing capacity of the structure.
[0073] (4) Crack-resistant mesh: The crack-resistant mesh should be kept at a certain distance from the outer wall of the concrete, that is, there should be a protective layer on the outside of the crack-resistant mesh, especially at the tongue and groove joints, to ensure that the concrete can be effectively prevented from cracking and to enhance its integrity. The connection points of the crack-resistant mesh should be evenly distributed, and the mesh spacing should meet the design requirements.
[0074] Precautions during welding:
[0075] (1) Welding quality: All welding points should meet the relevant welding standards and quality requirements to avoid welding defects such as cracks, porosity, slag inclusions, etc.
[0076] (2) Welding sequence: The welding sequence should be carried out in accordance with the design requirements. Usually, it should start from the main reinforcement, and then weld the cross reinforcement, spiral reinforcement and anti-crack mesh in sequence to ensure the stability of each part during the welding process.
[0077] Furthermore, this utility model embodiment also provides a method for reinforcing the dotted protrusions and recesses of precast segments.
[0078] Specifically, the reinforcement method includes:
[0079] S10, a steel reinforcement framework for lapped dotted tenons to strengthen the dotted tenons;
[0080] S20, a steel reinforcement framework for overlapping dotted tenons to strengthen the dotted tenons.
[0081] In some embodiments, the reinforcing steel reinforcement framework of the overlapping dovetail tenon in step S10 to strengthen the dovetail tenon includes:
[0082] S11, the steel cage 1 at the welded dotted tenon serves as the load-bearing skeleton, such as Figure 8 As shown in (a);
[0083] S12, the cross bars 2 reinforcing the dotted tenon are connected to the reinforcing cage 1 at the dotted tenon, for example, by welding, and the cross bars 2 reinforcing the dotted tenon are at least partially located inside the dotted tenon, such as... Figure 8 As shown in (b), the "red solid dots" represent the welding points between the cross bars 2 of the reinforcing dot tenon and the steel cage 1 at the dot tenon.
[0084] S13, the spiral rib 3 reinforcing the dotted tenon is connected to the cross rib 2 reinforcing the dotted tenon, for example, by welding, and the spiral rib 3 reinforcing the dotted tenon is at least partially located inside the dotted tenon, such as... Figure 8 As shown in (c), the "blue solid dots" represent the welding points of the spiral rib 3 of the reinforcing dot tenon and the intersecting rib 2 of the reinforcing dot tenon;
[0085] S14, connect the anti-crack mesh 4 of the reinforcing dotted tenon to the cross rib 2 of the reinforcing dotted tenon, and make the protrusion of the anti-crack mesh 4 of the reinforcing dotted tenon located outside the cross rib 2 and the spiral rib 3 of the reinforcing dotted tenon, such as Figure 8 As shown in (d), the "yellow solid dots" represent the welding points of the anti-crack mesh 4 of the reinforcing dotted tenon and the intersecting ribs 2 of the reinforcing dotted tenon.
[0086] When the anti-crack mesh 4 for reinforcing the dovetail joint and the intersecting reinforcement 2 for reinforcing the dovetail joint cannot be directly overlapped, short steel bars are used to connect the anti-crack mesh 4 for reinforcing the dovetail joint and the intersecting reinforcement 2 for reinforcing the dovetail joint. Figure 8 (d) and Figure 8 In (e), the short yellow line between the two weld points (solid yellow dots) represents a short steel bar.
[0087] In some embodiments, the reinforcement method further includes:
[0088] S15, pour concrete 5 to complete the targeted reinforcement of the segment tenon, such as Figure 8 As shown in (e).
[0089] When constructing a reinforcing steel reinforcement cage with overlapping dovetail joints, the requirement is met that smaller diameter reinforcing bars and anti-crack mesh be fixed to larger diameter reinforcing bars before pouring concrete.
[0090] In some embodiments, the reinforcing steel reinforcement framework of the overlapping dovetail joint in step S20 to strengthen the dovetail joint includes:
[0091] S21, the steel cage 6 at the welded dotted tenon serves as the load-bearing skeleton, such as Figure 11 As shown in (a);
[0092] S22, connect the spiral reinforcement 7 of the reinforced dotted tenon to the steel cage 6 at the dotted tenon, for example, by welding them together. Figure 11 As shown in (b), the "red solid dots" represent the welding points between the spiral reinforcement 7 of the reinforcing tenon and the steel cage 6 of the reinforcing tenon.
[0093] S23, the anti-crack mesh 8 for reinforcing the dotted tenon is connected to the spiral rib 7 for reinforcing the dotted tenon, for example, by welding, and the anti-crack mesh 8 for reinforcing the dotted tenon is located outside the spiral rib 7 for reinforcing the dotted tenon, and the recessed portion of the spiral rib 7 for reinforcing the dotted tenon is at least partially embedded in the spiral rib 7 for reinforcing the dotted tenon, such as... Figure 11 As shown in (c), the "blue solid dots" represent the welding points between the anti-crack mesh 8 and the spiral reinforcement 7.
[0094] When the anti-crack mesh 8 and the spiral reinforcement 7 of the reinforcing tenon cannot be directly overlapped, short steel bars are used to connect the anti-crack mesh 8 and the spiral reinforcement 7 of the reinforcing tenon. Figure 11 (c) and Figure 11 In the middle (d), the short blue line between the two weld points ("blue solid dots") represents a short steel bar.
[0095] In some embodiments, the reinforcement method further includes:
[0096] S24, pouring concrete at the tenon joint 9 completes the targeted reinforcement of the segment tenon, such as... Figure 11 As shown in (d).
[0097] When constructing a reinforcing steel reinforcement framework with overlapping dovetail joints, the requirement is met that smaller diameter reinforcing bars and anti-crack mesh be fixed to larger diameter reinforcing bars before pouring concrete.
[0098] In this embodiment of the utility model, the above-mentioned technical solution is used to reinforce the convex and concave tenons of the tunnel segments during the prefabrication stage. This not only improves 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. It is particularly outstanding when local reinforcement is required.
[0099] Furthermore, this embodiment of the invention also conducts damage performance tests on the reinforcement structure of the tenon and mortise joints of the precast segment.
[0100] Specifically, this embodiment of the invention uses the finite element method to establish finite element models corresponding to different reinforcement schemes, setting the same material parameters and shear loads. The concrete grade is C55, and the concrete damage (CDP) constitutive model is used, with an elastic modulus of 35.5 GPa, Poisson's ratio of 0.2, and a density of 2.4 t / m³. 3 The reinforcing cage uses φ25 steel bars, the cross bars and spiral bars are all φ6 steel bars, and the crack-resistant mesh is φ2 steel bars. All of these components have an elastic modulus of 210 GPa, a Poisson's ratio of 0.3, and a density of 7.85 t / m³. 3 The shear load is 250 kPa.
[0101] Model ①: Only the cross ribs 2 reinforce the point-shaped tenons;
[0102] Model ②: The tenon is reinforced by the cross rib 2 and the spiral rib 3; at the same time, the tenon is reinforced by the spiral rib 7.
[0103] Model ③: The point-shaped protruding tenon is reinforced by cross ribs 2, spiral ribs 3, and crack-resistant mesh 4; at the same time, the point-shaped concave tenon is reinforced by spiral ribs 7 and crack-resistant mesh 8.
[0104] Taking the DAMAGEC damage of the concrete under compression on the tenon side segment as an example, such as Figure 12 As shown, it can be intuitively seen that the concrete damage volume obtained based on model ③ is the smallest. Therefore, compared with the cases of only using cross reinforcement or a combination of cross reinforcement and spiral reinforcement, i.e., models ① and ②, the technical solution provided by this utility model, i.e., model ③, can effectively reduce the concrete damage volume.
[0105] The DAMAGEC damage under compression of the concrete on the concave-tenon side is similar to that on the convex-tenon side, and will not be described further here.
[0106] Figure 13Figure (a) shows the DAMAGEC volume of concrete under compressive damage at different damage levels for the three models. Overall, model ③ performs best at all damage levels, especially at high damage levels (0.9-1.0), where the damage volume is significantly lower than that of models ① and ②. This indicates that model ③ is the most effective in limiting segment damage. Figure 13 Figure (b) shows the volume of concrete tensile damage DAMAGET under different damage levels for the three models. Figure 13 Similar to (a), Model ③ has a lower damage volume at all damage levels, especially at high damage levels (0.9-1.0), where the damage volume of Model ③ is significantly smaller than that of Model ① and Model ②, showing better damage resistance.
[0107] Furthermore, the damage volumes corresponding to damage levels of 0.9-1.0 are statistically summarized and listed in Table 1. Table 1 shows the maximum misalignment, maximum principal stress of the reinforcing steel, 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., under a pressure of 250 kPa, for three reinforcement cases.
[0108] Table 1. Misalignment and mechanical parameters of tenons under the same loading conditions in three reinforcement cases.
[0109]
[0110] Table 1 shows that under a pressure of 250 kPa, Model ③, i.e., the technical solution provided by this invention, has the best effect in limiting segment misalignment, and also has the smallest concrete damage volume, while the principal stress of the reinforcing steel is the largest. This indicates that the reinforcing steel bears part of the load, thus limiting concrete damage. The compressive and tensile damage volumes corresponding to damage levels of 0.9-1.0 are reduced by 55.38% and 40.40%, respectively. Meanwhile, the difference in misalignment is not significant, but it also shows a decreasing trend.
[0111] Based on the above performance tests, we can conclude that:
[0112] (1) By optimizing the reinforcement, the steel bars can bear part of the load, reducing the stress on the concrete and thus improving the shear and bending resistance of the segment joint.
[0113] (2) By rationally arranging anti-crack mesh and fine steel bars, the development of cracks in concrete can be effectively controlled, preventing stress concentration and localized cracking. This helps maintain the integrity and airtightness of the structure and reduces water leakage. The anti-crack mesh with fine steel bars performs excellently in improving the crack resistance of concrete. At the same time, during construction, fine steel bars are easier to bend and shape, facilitating accurate placement by construction personnel and further ensuring the durability and reliability of the structure. The analysis results also show that although the difference in misalignment is not significant, there is a decreasing trend, indicating that optimizing the steel bar configuration helps to limit misalignment and improve joint stability.
[0114] (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.
[0115] It is understood that the types of tenons and mortises that can be reinforced by the technical solution provided by this utility model are not limited to those mentioned above. Figures 3 to 11 The dotted tenon and mortise joints specifically shown in the embodiments can also include runway-shaped distributed tenons and mortise joints and through tenons and mortise joints. During implementation, only the shape of the anti-crack mesh needs to be adjusted to adapt to the shape of the runway-shaped distributed tenon and mortise joints or through tenons and mortise joints.
[0116] Furthermore, the technical solution provided by this utility model can also be used to reinforce other similar components that have shear or bending resistance.
[0117] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of this utility model disclosure, even when only a single embodiment is described with respect to a particular feature. The feature examples provided in this utility model disclosure are intended to be illustrative and not limiting, unless otherwise stated. In practice, one or more technical features of the dependent claims may be combined with the technical features of the independent claims as needed and where technically feasible, and the technical features from the respective independent claims may be combined in any suitable manner rather than solely by the specific combinations listed in the claims.
[0118] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.
Claims
1. A reinforcement structure for the tenon joint of precast tunnel segments, characterized in that: include: The reinforcing cage at the tenon joint; The spiral reinforcement bar for reinforcing the tenon is connected to the steel cage at the tenon. The anti-crack mesh for reinforcing the tenon is connected to the spiral rib of the reinforcing tenon and located outside the spiral rib of the reinforcing tenon; the anti-crack mesh for reinforcing the tenon has a recessed portion adapted to the tenon, the recessed portion being at least partially embedded in the spiral rib of the reinforcing tenon.
2. The reinforced structure according to claim 1, characterized in that: The reinforcing structure is poured together with the concrete at the tenon joint.
3. The reinforced structure according to claim 2, characterized in that: The anti-crack mesh of the reinforcing tenon is parallel to the outer wall of the concrete at the tenon.
4. The reinforced structure according to claim 1, characterized in that: The crack-resistant mesh of the reinforcing tenon is connected to the spiral reinforcement of the reinforcing tenon by short steel bars.
5. The reinforced structure according to claim 1, characterized in that: The segment tenon includes dot-shaped tenons, racetrack-shaped tenons, or through-type tenons.