A reinforcement structure for segmental cracking in long-span continuous concrete box girders
By setting up a multi-layered steel plate structure inside and outside the box girder, the problem of coordinated stress performance at the joints of long-span continuous box girder segments was solved, the bending and torsional bearing capacity and dynamic stiffness were improved, the connection strength between the steel plate and the box girder was enhanced, and the construction difficulty was reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUBEI COMM PLANNING & DESIGN INST CO LTD
- Filing Date
- 2025-04-29
- Publication Date
- 2026-05-26
AI Technical Summary
In existing technologies, the joint strength of concrete and steel plates at the joints of long-span continuous box girders is reduced, resulting in poor reinforcement effect and insufficient bending, torsional bearing capacity and dynamic stiffness.
Multiple sets of longitudinal narrow and wide steel plates are installed inside and outside the box girder and anchored by anchor bolts to form a multi-layered steel plate structure, which improves the bending load-bearing capacity, prevents longitudinal cracks, and enhances the connection strength between the steel plates and the box girder.
It significantly improves the box girder's bending, torsional bearing capacity and crack resistance, enhances the contact stability between the steel plate and the box girder, reduces construction difficulty and improves construction efficiency.
Smart Images
Figure CN224281059U_ABST
Abstract
Description
Technical Field
[0001] The embodiments of this utility model belong to the field of continuous box girder reinforcement technology, and more specifically, relate to a reinforcement structure for segmental cracking of large-span concrete continuous box girders. Background Technology
[0002] Early construction of large-span continuous box girders often resulted in defects in the segmental construction joints due to their large spans and less mature construction techniques. During operation, overloaded vehicles can easily cause cracks to form at these joints. Common reinforcement methods for concrete beam segmental joints include: external concrete encapsulation, fiber composite material bonding, and steel plate bonding.
[0003] Traditional concrete-encased reinforcement methods significantly increase the structure's self-weight and require dense reinforcement mesh installation on the concrete surface, resulting in long construction cycles and inconsistent quality during operation. Fiber-bonded composite reinforcement can improve the structure's flexural strength and crack resistance, but it does not contribute to improving torsional strength or dynamic stiffness. Steel plate bonding comprehensively improves the structure's flexural strength, crack resistance, and dynamic stiffness, and has been widely used in bridge engineering renovation and reinforcement. In recent years, steel plate bonding has also been frequently used in the reinforcement of large-span concrete box girder bridges. However, in existing bridge steel plate bonding implementations, the reinforced surface and the steel plate are in single-sided contact. The bonding effect depends entirely on the adhesive. Uneven adhesive distribution leads to insufficient bonding area between the bridge and the steel plate, resulting in gaps and loose bonding, reducing the reliability of the bond and decreasing the synergistic stress performance of the concrete and steel plate, thus reducing the reinforcement effect.
[0004] Therefore, there is an urgent need at present for a reinforcement structure for continuous box girder segmental cracking, which strengthens the connection between the bridge and the steel plate and can effectively improve the box girder's bending and torsional bearing capacity, crack resistance and dynamic stiffness. Summary of the Invention
[0005] In view of the problems of reduced co-load capacity of concrete and steel plate at segmental joints and poor reinforcement effect in existing technologies, this utility model provides a reinforcement structure for cracking of segmental joints in large-span concrete continuous box girders to solve such problems.
[0006] To achieve the above objectives, this utility model provides a reinforcement structure for segmental cracking of a long-span continuous concrete box girder, comprising an inner reinforcement component located inside the box girder, which includes multiple sets of first longitudinal narrow steel plates fixed at intervals along the bridge direction on the inner bottom plate, and straight wide steel plates fixed at the front and rear ends of the inner bottom plate respectively along the transverse bridge direction, the straight wide steel plates being located on top of the longitudinal narrow steel plates and covering the segmental crack area; an outer reinforcement component located outside the box girder, which includes multiple sets of second longitudinal narrow steel plates fixed at intervals along the bridge direction at the bottom of the outer bottom plate, and U-shaped wide steel plates respectively located at both ends of the outer side of the box girder, the U-shaped wide steel plates covering the segmental crack area; and anchor bolts for anchoring the steel plates in the structure to the box girder.
[0007] Furthermore, multiple sets of third longitudinal narrow steel plates are fixedly installed at intervals along the bridge direction on the outer side of the web of the box girder.
[0008] Furthermore, the U-shaped wide steel plate has a U-shaped structure that is adapted to the outer side of the box girder. The bottom of the U-shaped wide steel plate is fixedly connected to the bottom of the second longitudinal narrow steel plate, and the two sides are fixedly connected to the third longitudinal narrow steel plate, thus covering the bottom of the front and rear segment joints at both ends of the box girder.
[0009] Furthermore, straight narrow steel plates are respectively provided along the transverse direction at the middle segment of the box girder, and the straight narrow steel plates are fixedly installed on the top of the first longitudinal narrow steel plate.
[0010] Furthermore, a U-shaped narrow steel plate is provided at the middle section of the box girder. The bottom of the U-shaped narrow steel plate is fixedly installed at the bottom of the second longitudinal narrow steel plate, located at the middle section of the outer bottom plate. Its two sides are fixedly connected to the outer side of the third longitudinal narrow steel plate, located at the middle section of the web plate.
[0011] Furthermore, the bottom plate is equipped with bottom plate through anchor bolts to anchor the steel plate at the same elevation.
[0012] Furthermore, the web of the box girder is provided with web non-penetrating anchor bolts for anchoring steel plates, and the web non-penetrating anchor bolts have an inverted conical structure.
[0013] Furthermore, the variable-height section of the box girder is equipped with a bottom plate non-penetrating anchor bolt for anchoring the steel plate. The bottom plate non-penetrating anchor bolt has an inverted conical structure.
[0014] In summary, compared with the prior art, the above-described technical solution conceived by this utility model can achieve the following beneficial effects:
[0015] (1) The reinforcement structure of this utility model, by providing a first longitudinal narrow steel plate, a second longitudinal narrow steel plate and a third longitudinal narrow steel plate along the bridge direction, forms a first layer of clamping steel plates on the inner and outer sides of the box girder, which can significantly improve the bending bearing capacity of the box girder and prevent transverse cracks from occurring at other locations other than the segment joints due to uneven stiffness; by providing a straight wide steel plate and a U-shaped wide steel plate to cover the bottom of the front segment joint and the rear segment joint at both ends of the box girder, the two form a second layer of clamping steel plates, which can effectively strengthen the cross-sectional stiffness of the box girder at the segment joint.
[0016] (2) The reinforcement structure of this utility model, by providing straight narrow steel plates and U-shaped narrow steel plates at the top and bottom of the middle section of the box girder along the transverse direction, can limit the generation of longitudinal cracks and strengthen the overall stress resistance of the longitudinal steel plates.
[0017] (3) The reinforcement structure of this utility model strengthens the connection between the steel plate and the box girder by setting bottom plate through anchor bolts to anchor the steel plate in the bottom plate equal height section, which can realize the stability and reliability of the contact surface between the steel plate and the box girder and the coordinated force; by setting non-through anchor bolts to anchor the variable height section and the web plate, the stability and reliability of the contact surface between the steel plate and the variable height section and the web plate can be realized and the coordinated force can be realized; the steel plate and the anchor bolts are detachable and can be quickly replaced, reducing the construction difficulty and thus improving the construction efficiency. Attached Figure Description
[0018] Figure 1 This is a cross-sectional schematic diagram of the transverse reinforcement structure of the box girder in an embodiment of this utility model;
[0019] Figure 2 This is a schematic diagram of the outer bottom plate of the box in an embodiment of this utility model;
[0020] Figure 3 This is a schematic diagram of the bottom plate inside the box in an embodiment of this utility model.
[0021] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-straight wide steel plate, 2-first longitudinal narrow steel plate, 3-U-shaped wide steel plate, 4-bottom plate through anchor bolt, 5-bottom plate non-through anchor bolt, 6-box girder, 61-bottom plate, 611-inner bottom plate section, 612-outer bottom plate section, 62-web plate, 63-variable height section, 7-U-shaped narrow steel plate, 8-front segment joint, 9-rear segment joint, 10-straight narrow steel plate, 11-web plate non-through anchor bolt, 12-second longitudinal narrow steel plate, 13-third longitudinal narrow steel plate. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.
[0023] like Figure 1-3 As shown, this utility model provides a reinforcement structure for segmental cracking of a long-span continuous concrete box girder, comprising an inner reinforcement component located inside the box girder 6 and an outer reinforcement component located outside the box girder 6. The inner reinforcement component includes multiple sets of first longitudinal narrow steel plates 2 fixed at intervals along the bridge direction on the inner bottom plate 611, and straight wide steel plates 1 fixed at the front and rear ends of the inner bottom plate 611 respectively along the transverse bridge direction. The straight wide steel plates 1 are located on top of the longitudinal narrow steel plates 2 and cover the segmental crack area. The outer reinforcement component includes multiple sets of second longitudinal narrow steel plates 12 fixed at intervals along the bridge direction at the bottom of the outer bottom plate 612, and U-shaped wide steel plates 3 respectively located at both ends of the outer side of the box girder 6. The U-shaped wide steel plates 3 cover the segmental crack area. The reinforcement structure of this utility model can significantly improve the bending load-bearing capacity of the box girder by setting longitudinal narrow steel plates inside and outside the bottom plate of the box girder, and prevent transverse cracks from occurring in other locations outside the segment joints due to uneven stiffness. By covering the top and bottom of the segment joint area with straight wide steel plates 1 and U-shaped wide steel plates 3 respectively, the stiffness of the box girder section at the segment joint can be effectively reinforced. In this structure, all steel plates are anchored with anchor bolts to ensure full contact between the steel plates and the box girder, making it stable and reliable, thereby effectively improving the bending and torsional load-bearing capacity, crack resistance and dynamic stiffness of the box girder segment joints.
[0024] like Figure 1 As shown, the box girder is an existing large-span continuous concrete box girder. The segmental joint of the box girder refers to the joint formed between the box girder segments during the construction of a multi-span continuous box girder bridge to accommodate segmented casting or assembly processes. The continuous box girder forms an integral load-bearing structure through the segmental joints. The joints need to transmit bending moment, shear force, and torque, requiring extremely high construction precision and material properties. Figure 2-3 In this context, the segmental joint includes a front segmental joint 8 and a rear segmental joint 9, which are joints formed between box girder segments during construction.
[0025] In this embodiment of the utility model, by providing longitudinal narrow steel plates along the bridge direction on the inner and outer sides of the box girder 6, a longitudinally encasing steel plate is formed, which can significantly improve the bending bearing capacity of the box girder and prevent transverse cracks from occurring at locations other than the segmental joints due to uneven stiffness. The longitudinal narrow steel plates include a first longitudinal narrow steel plate 2, a second longitudinal narrow steel plate 12, and a third longitudinal narrow steel plate 13. The first longitudinal narrow steel plate 2 is fixedly disposed at intervals along the bridge direction on the inner bottom plate 611. The second longitudinal narrow steel plate 12 is fixedly disposed at intervals along the bridge direction at the bottom of the outer bottom plate 612, and the second longitudinal narrow steel plate 12 and the first longitudinal narrow steel plate 2 are symmetrically disposed at the top and bottom of the bottom plate 61. The third longitudinal narrow steel plate 13 is fixedly disposed at intervals along the bridge direction on the outer side of the web plate 62.
[0026] By using the first longitudinal narrow steel plate 2, the second longitudinal narrow steel plate 12, and the third longitudinal narrow steel plate 13 installed along the bridge direction, the three form the first layer of steel plates sandwiching the inner and outer sides of the box girder 6, which can significantly improve the bending bearing capacity of the box girder and prevent transverse cracks from occurring at other locations besides the segmental joints due to uneven stiffness.
[0027] In this embodiment of the utility model, by covering the segmental joint area with a straight wide steel plate 1 and a U-shaped wide steel plate 3, the cross-sectional stiffness of the box girder at the segmental joint can be effectively reinforced. The straight wide steel plate 1 is fixedly installed on top of the longitudinal narrow steel plate 2, covering the top of the front segmental joint 8 and the rear segmental joint 9 at both ends of the box girder 6. The U-shaped wide steel plate 3 has a U-shaped structure that is adapted to the outer side of the box girder 6. The bottom of the U-shaped wide steel plate 3 is fixedly connected to the bottom of the second longitudinal narrow steel plate 12, and the two sides are fixedly connected to the third longitudinal narrow steel plate 13, covering the bottom of the front segmental joint 8 and the rear segmental joint 9 at both ends of the box girder 6.
[0028] By covering the bottom of the front segment joint 8 and the rear segment joint 9 at both ends of the box girder 6 with straight wide steel plate 1 and U-shaped wide steel plate 3, the two form a second layer of sandwich steel plate, which can effectively strengthen the cross-sectional stiffness of the box girder at the segment joint.
[0029] Furthermore, to limit the generation of longitudinal cracks and enhance the overall load-bearing capacity of the longitudinal steel plates, straight narrow steel plates 10 and U-shaped narrow steel plates 7 are respectively provided along the transverse direction at the middle segment of the box girder 6. The straight narrow steel plate 10 is fixedly installed on the top of the first longitudinal narrow steel plate 2, located at the middle segment of the inner bottom plate 611; the bottom of the U-shaped narrow steel plate 7 is fixedly installed on the bottom of the second longitudinal narrow steel plate 12, located at the middle segment of the outer bottom plate 612, and its two sides are respectively fixedly connected to the outer side of the third longitudinal narrow steel plate 13, located at the middle segment of the web 62.
[0030] In this embodiment of the invention, all steel plates in the structure are anchored with anchor bolts to ensure full contact between the steel plates and the box girder. Specifically, bottom plate through anchor bolts 4 are used on the bottom plate 1 to anchor the bottom of the U-shaped wide steel plate 3, the second longitudinal narrow steel plate 12, the first longitudinal narrow steel plate 2, the bottom of the U-shaped narrow steel plate 7, and the straight narrow steel plate 10. At the height-changing section 63 of the box girder 61, bottom plate non-through anchor bolts 5 are used to anchor the bottom of the U-shaped wide steel plate 3 and the U-shaped narrow steel plate 7 in this area. These bottom plate non-through anchor bolts 5 have an inverted conical structure, effectively increasing the anchoring area and improving anchoring stability. At the web of the box girder 61, web non-through anchor bolts 11 are used to anchor the third longitudinal narrow steel plate 13, the side of the U-shaped wide steel plate 3, and the side of the U-shaped narrow steel plate 7. These web non-through anchor bolts 11 have an inverted conical structure, effectively increasing the anchoring area and improving anchoring stability.
[0031] The present invention describes a reinforcement structure for segmental cracking in a long-span continuous concrete box girder. By installing through-bolts 4 on the bottom plate 61 at equal elevations to anchor the steel plate, stability and reliability of the contact surface between the steel plate and the box girder are achieved, ensuring coordinated stress distribution. Similarly, by installing non-through-bolts on the variable elevation section 63 and the web 62, stability and reliability of the contact surface between the steel plate and the variable elevation section 63 and the web 62 are achieved, ensuring coordinated stress distribution. The steel plate and anchors are detachable, allowing for quick replacement, reducing construction difficulty, and thus improving construction efficiency.
[0032] This structure can be extended longitudinally as needed; this utility model can be widely used in the reinforcement and treatment of segmental cracks in large-span continuous concrete box girders.
[0033] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A reinforcing structure for opening cracks of a large-span concrete continuous box girder segment, characterized by, include: The internal reinforcement assembly located inside the box girder (6) includes multiple sets of first longitudinal narrow steel plates (2) fixed at intervals along the longitudinal direction on the inner bottom plate (611), and straight wide steel plates (1) fixed at the front and rear ends of the inner bottom plate (611) respectively along the transverse direction. The straight wide steel plates (1) are located on top of the longitudinal narrow steel plates (2) to cover the segmental joint area. The external reinforcement assembly located on the outside of the box girder (6) includes multiple sets of second longitudinal narrow steel plates (12) fixed at intervals along the bridge direction at the bottom of the outer bottom plate (612), and U-shaped wide steel plates (3) respectively located at both ends of the outside of the box girder (6), the segmental joint area of the U-shaped wide steel plate (3) is covered; And anchor bolts that anchor the steel plates in the structure to the box girder (6).
2. The reinforcing structure for opening cracks of large-span concrete continuous box girder segmental joints according to claim 1, characterized in that, Multiple sets of third longitudinal narrow steel plates (13) are fixedly installed on the outer side of the web (62) of the box girder (6) along the bridge direction.
3. The reinforcing structure for opening cracks of large-span concrete continuous box girder segmental joints according to claim 2, characterized in that, The U-shaped wide steel plate (3) is a U-shaped structure that is adapted to the outer side of the box girder (6). The bottom of the U-shaped wide steel plate (3) is fixedly connected to the bottom of the second longitudinal narrow steel plate (12), and the two sides are fixedly connected to the third longitudinal narrow steel plate (13), covering the bottom of the front segment joint (8) and the rear segment joint (9) at both ends of the box girder (6).
4. The reinforcing structure for the cracking of the segmental joint of the long-span concrete continuous box girder according to any one of claims 1-3, characterized in that, A straight narrow steel plate (10) is provided along the transverse direction at the middle segment of the box girder (6), and the straight narrow steel plate (10) is fixedly installed on the top of the first longitudinal narrow steel plate (2).
5. The reinforcing structure for opening cracks of large-span concrete continuous box girder segmental joints according to claim 2, characterized in that, The box girder (6) is also provided with a U-shaped narrow steel plate (7) at the middle section. The bottom of the U-shaped narrow steel plate (7) is fixedly located at the bottom of the second longitudinal narrow steel plate (12) at the middle section of the outer bottom plate (612). Its two sides are fixedly connected to the outer side of the third longitudinal narrow steel plate (13) at the middle section of the web plate (62).
6. The reinforcing structure for opening cracks of large-span concrete continuous box girder segmental joints according to any one of claims 1-3, characterized in that, The bottom plate (61) is provided with bottom plate through anchor bolts (4) at the same height section to anchor the corresponding steel plates.
7. The reinforcing structure for opening cracks of large-span concrete continuous box girder segmental joints according to any one of claims 1-3, characterized in that, The web plate (62) of the box girder (6) is provided with a web non-penetrating anchor bolt (11) to anchor the corresponding steel plate. The web non-penetrating anchor bolt (11) has an inverted conical structure.
8. The reinforcing structure for opening cracks of large-span concrete continuous box girder segment according to any one of claims 1-3, characterized in that, The box girder (6) is provided with a non-penetrating anchor bolt (5) at the height-changing section (63) to anchor the corresponding steel plate. The non-penetrating anchor bolt (5) is an inverted conical structure.