Bridge superstructure widening structure based on steel structure cover beam

Abstract

The utility model discloses a bridge upper portion splicing wide structure based on steel structure bent cap belongs to bridge engineering technical field, including existing bridge structure, extension support structure, newly added upper portion structure, connecting assembly, bridge deck system and guardrail structure, extension support structure is the steel structure bent cap of along existing bent cap outside side joint length, is fixed with existing bent cap through connecting piece and forms support platform, newly added upper portion structure is steel -concrete superposed beam, is located on support platform and span is identical with existing bridge, is connected with existing main beam through steel cross diaphragm and wet joint, existing bridge outside side guardrail and part cantilever are chiseled, and guardrail structure is located in newly added upper portion structure outside side. This structure need not newly add pier and platform, can realize the assembly construction, can intensive use land, save the time limit for a project, promote the integrity of bridge, is applicable to the expressway reconstruction and extension scene.

Description

Technical Field

[0001] This utility model belongs to the field of bridge engineering technology, specifically relating to a bridge superstructure widening structure based on a steel structure cap beam for existing precast T-beam or small box girder highway bridges. Background Technology

[0002] With the development of society and the economy, the traffic volume on expressways continues to grow. The service level of existing two-way four-lane expressways can no longer meet the demand, and there is an urgent need to upgrade them to two-way six-lane expressways through reconstruction and expansion to improve traffic capacity. In expressway reconstruction and expansion projects, bridge widening is one of the key aspects.

[0003] Currently, the superstructure of most highway bridges in China uses precast T-beams or precast small box girders. The conventional widening methods mainly include three types: ① neither the superstructure nor the substructure is connected; ② the superstructure is connected, but the substructure is not; ③ both the superstructure and the substructure are connected. These conventional solutions need to be selected based on the actual conditions of the bridge, but all require the construction of pier foundations on the widened side to support the newly added superstructure.

[0004] However, in actual engineering projects, some bridge sections face challenges such as limited lateral space under the bridge (e.g., crossing rivers or roads) or difficulties in land acquisition and demolition. In these situations, the requirement for pier foundations in conventional widening schemes is difficult to meet—limited space under the bridge leads to insufficient operational space for pier foundation construction, while difficulties in land acquisition and demolition significantly increase project costs and timelines, severely hindering the smooth implementation of bridge reconstruction and expansion. Especially for existing precast T-beam or small box girder bridges, there is currently a lack of mature technical solutions for scenarios involving "widening the superstructure but not erecting piers," becoming a bottleneck restricting the reconstruction and expansion of such sections.

[0005] Therefore, there is an urgent need for a bridge widening structure suitable for road sections with limited space under transverse bridges or difficult land acquisition and demolition, in order to solve the problem of relying on new pier foundations in conventional solutions and achieve efficient and economical bridge superstructure widening. Utility Model Content

[0006] In view of this, the purpose of this utility model is to overcome the shortcomings of existing related technologies and provide a bridge superstructure widening structure based on steel structure cap beams. The purpose is to address the difficulties in implementing conventional widening schemes due to the need for pier foundations in road sections where existing bridges are precast T-beams or precast small box girders and where there are limitations on lateral space under the bridge or difficulties in land acquisition and demolition during bridge widening. This will meet the needs of highway reconstruction and expansion (such as the expansion of a two-way four-lane road to a two-way six-lane road) to improve service levels. At the same time, by adopting a widening scheme with superstructure widening and no piers under the bridge, as well as a compact cross-section design, the present invention achieves the effects of intensive land use, saving construction time, reducing project costs, and reducing carbon emissions.

[0007] To achieve the above objectives, this utility model provides a bridge superstructure widening structure based on a steel structure cap beam, including an existing bridge structure, an extended support structure, a newly added superstructure, connecting components, a bridge deck system, and a guardrail structure.

[0008] The existing bridge structure includes the existing cap beam, the existing main beam and the existing bridge deck, wherein the existing main beam is a precast T-beam or a precast small box girder;

[0009] The extended support structure is a steel structure cap beam that extends along the outside of the existing cap beam and is fixedly connected to the existing cap beam through connectors to form an outwardly expanding support platform.

[0010] The newly added superstructure is set on the support platform of the extended support structure, and its span is consistent with the span of the existing bridge structure. The newly added superstructure is connected to the existing main beam through connecting components.

[0011] The outer guardrail and part of the cantilever of the existing bridge structure were removed, and the guardrail structure was set on the outer edge of the newly added superstructure.

[0012] The bridge deck system covers the connection area between the new superstructure and the existing bridge deck, as well as the top of the new superstructure.

[0013] Furthermore, the connector is an anchor bolt, which is distributed longitudinally along the existing cap beam, with one end inserted into the existing cap beam and the other end fixedly connected to the steel structure cap beam.

[0014] Furthermore, the newly added superstructure is a steel-concrete composite beam, including a steel main beam and a precast bridge deck, wherein the precast bridge deck covers the top of the steel main beam and is fixedly connected.

[0015] Furthermore, the connecting components include steel diaphragms and wet joints; the steel diaphragms are arranged at intervals along the longitudinal direction of the bridge, and their number and position correspond one-to-one with the diaphragms between beams in the existing bridge structure. The two ends of the steel diaphragms are fixedly connected to the new superstructure and the existing main beam, respectively; the wet joints are located between the bridge deck of the new superstructure and the existing bridge deck, connecting the two into a whole.

[0016] Furthermore, the wet joint is provided with connecting steel bars, the two ends of which are connected to the exposed steel bars of the existing bridge deck and the exposed steel bars of the bridge deck of the newly added superstructure, respectively. The wet joint is made of concrete.

[0017] Furthermore, the guardrail structure is a steel guardrail, and its impact resistance level is consistent with that of the outer guardrail of the existing bridge structure. The steel guardrail is fixedly connected to the newly added superstructure through embedded parts.

[0018] Furthermore, the bridge deck system includes a leveling layer, a waterproof layer, and an asphalt pavement layer. The leveling layer covers the wet joints and the top of the newly added superstructure, the waterproof layer is located above the leveling layer, and the asphalt pavement layer is located above the waterproof layer.

[0019] Furthermore, rubber pads are provided at the connection between the steel structure cap beam and the existing cap beam, and the rubber pads are arranged at intervals along the longitudinal direction of the connection.

[0020] Furthermore, emergency parking lanes are provided at predetermined intervals along the longitudinal direction of the bridge, with priority given to the roadbed section.

[0021] The present invention, by adopting the above technical solution, has at least the following beneficial effects:

[0022] In this utility model, a support platform is formed by extending a steel structure cap beam along the outer side of the existing cap beam. This eliminates the need to add new pier foundations under the bridge, effectively solving the problem of widening bridges in sections where the transverse space under the bridge is limited or where land acquisition and demolition are difficult. This breaks through the limitations of conventional solutions that rely on pier foundations, enabling the reconstruction and expansion of such road sections to be implemented smoothly and meeting the traffic demand for the expansion of expressways from two-way four lanes to two-way six lanes.

[0023] In this utility model, the newly added superstructure adopts a steel-concrete composite beam, which is connected to the existing main beam through steel diaphragms (the number and position of which correspond one-to-one with the diaphragms of the old bridge) and wet joints. The steel diaphragms enhance the longitudinal integrity of the new and old structures, and the wet joints realize the rigid connection between the new and old bridge decks, which greatly improves the overall stress performance and structural stability of the bridge after widening, and ensures traffic safety.

[0024] In this utility model, steel components such as steel structure cap beams and steel-concrete composite beams can be prefabricated in the factory and quickly installed on site through anchor bolts, welding, and other methods. This is a prefabricated construction method, which reduces the amount of on-site pouring work. It not only saves the construction period but also reduces the impact on existing traffic and the surrounding environment. At the same time, it avoids the temporary land occupation problem caused by building a new beam yard, which is conducive to protecting the ecological environment.

[0025] In this utility model, the guardrail structure adopts steel guardrail, which significantly reduces its self-weight compared with traditional concrete guardrail, reduces the load of the new structure on the supporting platform, and its anti-collision level is consistent with the existing guardrail. While optimizing the structural stress, it ensures the protective performance. At the same time, the overall solution does not require the addition of piers, which greatly reduces land occupation and demolition costs, meets the requirements of intensive land use and low-carbon construction, and reduces the project cost. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the cross-section of an existing T-beam bridge;

[0028] Figure 2 This is a schematic diagram of the expanded cross-section of a T-beam bridge according to this utility model;

[0029] Figure 3 This is one of the detailed drawings of the upper structure of this utility model;

[0030] Figure 4 This is the second detailed drawing of the upper structure of this utility model.

[0031] Figure 5 This is a schematic diagram of the steel cross diaphragm arrangement of this utility model;

[0032] Figure 6 This utility model relates to a steel cap beam structure. Figure 1 ;

[0033] Figure 7 This utility model relates to a steel cap beam structure. Figure 2 ;

[0034] Figure 8 This is a schematic diagram of the expanded cross-section of a small box girder bridge according to this utility model.

[0035] In the diagram: 1. Existing cap beam; 2. Steel structure cap beam; 3. Existing main beam; 4. Existing bridge deck; 5. Steel-concrete composite beam; 6. Steel main beam; 7. Precast bridge deck; 8. Steel diaphragm; 9. Wet joint; 10. Rubber pad; 11. Guardrail structure. Detailed Implementation

[0036] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this invention as detailed in the appended claims.

[0037] Example 1

[0038] Please see Figures 1 to 8As shown, this embodiment provides a bridge superstructure widening structure based on a steel structure cap beam, including an existing bridge structure, an extended support structure, a new superstructure, connecting components, a bridge deck system, and a guardrail structure 11.

[0039] The existing bridge structure includes an existing cap beam 1, an existing main beam 3 and an existing bridge deck 4, wherein the existing main beam 3 is a precast T-beam or a precast small box beam;

[0040] The extended support structure is a steel structure cap beam 2 that extends along the outside of the existing cap beam 1 and is fixedly connected to the existing cap beam 1 through connectors to form an outwardly expanding support platform.

[0041] The newly added superstructure is set on the support platform of the extended support structure, and its span is consistent with the span of the existing bridge structure. The newly added superstructure is connected to the existing main beam 3 through connecting components.

[0042] The outer guardrail and part of the cantilever of the existing bridge structure were removed, and the guardrail structure 11 was set on the outer edge of the newly added superstructure.

[0043] The bridge deck system covers the connection area between the new superstructure and the existing bridge deck 4, as well as the top of the new superstructure.

[0044] In one embodiment, the connector is an anchor bolt. The anchor bolts are distributed longitudinally along the existing cap beam 1, with one end inserted into the existing cap beam 1 and the other end fixedly connected to the steel structure cap beam 2.

[0045] In one embodiment, the newly added superstructure in this example is a steel-concrete composite beam 5, which includes a steel main beam 6 and a precast bridge deck 7. The precast bridge deck 7 covers the top of the steel main beam 6 and is fixedly connected.

[0046] In one embodiment, the connecting components in this embodiment include steel diaphragms 8 and wet joints 9. The steel diaphragms 8 are arranged at intervals along the longitudinal direction of the bridge, and their number and position correspond one-to-one with the diaphragms between beams in the existing bridge structure. The two ends of the steel diaphragms 8 are fixedly connected to the new superstructure and the existing main beam 3, respectively. The wet joint 9 is located between the bridge deck of the new superstructure and the existing bridge deck 4, connecting the two into a whole.

[0047] In one embodiment, the wet joint 9 in this embodiment is provided with connecting steel bars. The two ends of the connecting steel bars are respectively connected to the exposed steel bars of the existing bridge deck 4 and the exposed steel bars of the bridge deck of the newly added superstructure. The wet joint 9 is made of concrete.

[0048] In one embodiment, the guardrail structure 11 described in this example is a steel guardrail, whose impact resistance level is consistent with that of the outer guardrail of the existing bridge structure. The steel guardrail is fixedly connected to the newly added superstructure through embedded parts.

[0049] In one embodiment, the bridge deck system in this example includes a leveling layer, a waterproof layer, and an asphalt pavement layer. The leveling layer covers the wet joint 9 and the top of the newly added superstructure. The waterproof layer is located above the leveling layer, and the asphalt pavement layer is located above the waterproof layer.

[0050] As one implementation method, in this embodiment, a rubber pad 10 is provided at the connection between the steel structure cap beam 2 and the existing cap beam 1, and the rubber pad 10 is arranged longitudinally at intervals along the connection.

[0051] As one implementation method, in this embodiment, emergency parking lanes are provided at preset intervals along the longitudinal direction of the bridge, and the emergency parking lanes are preferentially provided in the roadbed section.

[0052] Working principle explanation:

[0053] Figure 1 This is a schematic diagram of the cross-section of an existing T-beam bridge. Figure 2 This is a schematic diagram of the cross-section of the T-beam bridge expansion according to this utility model. The working principle of this bridge superstructure widening structure based on steel structure cap beam revolves around the core design of "superstructure widening without piers under the bridge". It achieves efficient widening of existing bridges (precast T-beams or small box girders) through the synergistic effect of various components, as detailed below:

[0054] 1. Force Transfer in the Support System: The extended support structure (steel structure cap beam) is fixed to the existing cap beam via connectors (anchor bolts), forming an outwardly expanding support platform. Rubber pads are installed at the connection points with the existing cap beam to buffer localized stresses caused by material differences or deformation under stress. The loads (including self-weight and vehicle loads) of the newly added superstructure (steel-concrete composite beam) are transferred to the existing cap beam through the steel structure cap beam, and then from the existing cap beam to the original substructure pier foundation. No new piers are needed, solving the problem of limited space under the bridge or difficulties in land acquisition and demolition that prevent the installation of new piers.

[0055] 2. Ensuring the integrity of the new and old structures: The new superstructure and the existing main beams form an integrated load-bearing system through connecting components: steel diaphragms are arranged longitudinally at intervals and their positions correspond one-to-one with the diaphragms between the existing bridge beams, which can synchronously transfer lateral forces and avoid relative displacement caused by uncoordinated forces between the new and old structures; the connecting steel bars in the wet joints connect the steel bars of the existing bridge deck and the new bridge deck into a whole, forming a rigid connection after concrete pouring, ensuring that the bridge deck load is evenly transferred between the new and old structures, and improving the overall stiffness and deformation resistance of the bridge after widening.

[0056] 3. Functional Adaptation and Safety Assurance: After the existing bridge's outer guardrails and part of the cantilever were removed, space was provided for the connection between the old and new structures. The newly added guardrail structure (steel guardrail) is fixed to the outside of the new superstructure, meeting the impact resistance requirements while reducing its own weight to decrease the load on the support platform. The bridge deck system covers the connection area and the top of the new superstructure. The leveling layer, waterproof layer, and asphalt pavement layer are installed sequentially to ensure a flat, waterproof, and smooth driving surface. Combined with the pre-set emergency parking lanes along the longitudinal direction (prioritized in the roadbed section), it adapts to the traffic requirements of a two-way six-lane road.

[0057] Through the synergistic effect of the above components, this structure enables the widening of the bridge superstructure without adding new piers, taking into account structural safety, construction feasibility and functional adaptability, and is suitable for road sections where the space under the bridge is limited or where land acquisition and demolition are difficult.

[0058] Example 2

[0059] like Figures 1 to 7 As shown, for bridge widening scenarios where the existing main girder is a precast T-beam (30m span), based on the working principle of Example 1 and combined with the structural characteristics of a 30m span T-beam, its adaptability working principle is as follows:

[0060] 1. Support and load transfer adaptation: The 30m span T-beam has a large self-weight, and the extended part of the steel structure cap beam is designed according to... Figure 6 and Figure 7 The “Steel Cap Beam Construction Drawing (Applicable to 30m T-beam)” design connects the T-beam to the existing cap beam using M24 anchor bolts (the anchor bolt insertion depth and spacing match the load distribution of the T-beam). Rubber pads (200×200×20mm) are spaced along the connection to buffer the vibration load when the T-beam is under stress, ensuring that the load is stably transferred to the existing cap beam.

[0061] 2. Lateral force transmission adaptation: The T-beam web is relatively thick and the lateral force is concentrated. The steel diaphragms are connected to the T-beam web by high-strength bolts and welded to the main steel beam of the newly added steel-concrete composite beam. This can efficiently transmit the lateral shear force generated by the vehicle load. The number of diaphragms corresponds one-to-one with the existing T-beam diaphragms. Figure 5 (As shown), to avoid cracks caused by stress concentration at the connection between the old and new structures.

[0062] 3. Bridge deck connection adaptation: After the outer cantilever of the T-beam is removed ( Figure 3 and Figure 4 The width of the wet joint is adapted to the remaining cantilever size. The internal connecting steel bars are welded to the exposed steel bars of the T-beam flange plate. After being poured with C50 concrete, a rigid transition is formed to ensure that the vehicle load is smoothly transferred from the new bridge deck to the existing T-beam bridge deck, which is adapted to the stress characteristics of the T-beam flange plate.

[0063] Example 3

[0064] See Figures 2 to 7 , combined Figure 8 For bridge widening scenarios where the existing main girder is a precast small box girder (30m span), based on the working principle of Example 1 and combined with the structural characteristics of the 30m span small box girder, its adaptability working principle is as follows:

[0065] 1. Support and load transfer compatibility: The small box girders are relatively evenly distributed laterally, and the extended parts of the steel structure cap beam are adapted according to the attached... Figure 6 and Figure 7 (Applicable to 30m small box girders) The connection parts (anchor bolts) spacing is adapted to the load distribution characteristics of the small box girder. The rubber pads (200×200×20mm) can buffer the overall deformation of the small box girder when it is under stress, ensuring that the load of the newly added superstructure is evenly transferred to the existing cap beam.

[0066] 2. Lateral force transmission adaptation: The top plate of the small box girder is relatively wide, and the steel diaphragm is connected to the outer web of the small box girder by bolts through embedded parts. Figure 5 The steel main beam of the newly added steel-concrete composite beam is welded to the steel main beam, which can be adapted to the characteristics of the lateral force distribution of the small box girder, and ensure that the new and old structures can jointly bear the lateral load.

[0067] 3. Bridge deck connection adaptation: After the outer cantilever of the small box girder is removed ( Figure 2 and Figure 3 The width of the wet joint is adapted to the cantilever size of the top slab. The connecting steel bars are mechanically connected to the exposed steel bars on the top slab of the small box girder. After concrete pouring, a smooth transition is formed, which is adapted to the characteristics of the wide top slab of the small box girder and the uniform load distribution, ensuring the smooth driving on the bridge deck.

[0068] Diagram of T-beam ( Figures 2 to 7 ) and the drawing of the small box girder ( Figure 8 The difference between them is the beam type; one is a T-beam, and the other is a small box girder. The widening scheme is the same.

[0069] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A bridge superstructure widening structure based on a steel cap beam, characterized in that: This includes existing bridge structures, external support structures, new superstructures, connecting components, bridge deck systems, and guardrail structures. The existing bridge structure includes the existing cap beam, the existing main beam and the existing bridge deck, wherein the existing main beam is a precast T-beam or a precast small box girder; The extended support structure is a steel structure cap beam that extends along the outside of the existing cap beam and is fixedly connected to the existing cap beam through connectors to form an outwardly expanding support platform. The newly added superstructure is set on the support platform of the extended support structure, and its span is consistent with the span of the existing bridge structure. The newly added superstructure is connected to the existing main beam through connecting components. The outer guardrail and part of the cantilever of the existing bridge structure were removed, and the guardrail structure was set on the outer edge of the newly added superstructure. The bridge deck system covers the connection area between the new superstructure and the existing bridge deck, as well as the top of the new superstructure.

2. The structure according to claim 1, characterized in that: The connector is an anchor bolt, which is distributed longitudinally along the existing cap beam. One end is inserted into the existing cap beam, and the other end is fixedly connected to the steel structure cap beam.

3. The structure according to claim 1, characterized in that: The newly added superstructure is a steel-concrete composite beam, including a steel main beam and a precast bridge deck, with the precast bridge deck covering the top of the steel main beam and fixedly connected.

4. The structure according to claim 1, characterized in that: The connecting components include steel diaphragms and wet joints; the steel diaphragms are arranged at intervals along the longitudinal direction of the bridge, and their number and position correspond one-to-one with the diaphragms between beams in the existing bridge structure. The two ends of the steel diaphragms are fixedly connected to the new superstructure and the existing main beam, respectively; the wet joints are located between the bridge deck of the new superstructure and the existing bridge deck, connecting the two into a whole.

5. The structure according to claim 4, characterized in that: The wet joint is equipped with connecting steel bars, and the two ends of the connecting steel bars are respectively connected to the exposed steel bars of the existing bridge deck and the exposed steel bars of the bridge deck of the newly added superstructure. The wet joint is made of concrete.

6. The structure according to claim 1, characterized in that: The guardrail structure is a steel guardrail, and its impact resistance level is the same as that of the outer guardrail of the existing bridge structure. The steel guardrail is fixedly connected to the new superstructure through embedded parts.

7. The structure according to claim 1, characterized in that: The bridge deck system includes a leveling layer, a waterproof layer, and an asphalt pavement layer. The leveling layer covers the wet joints and the top of the newly added superstructure. The waterproof layer is located above the leveling layer, and the asphalt pavement layer is located above the waterproof layer.

8. The structure according to claim 1, characterized in that: Rubber pads are provided at the connection between the steel structure cap beam and the existing cap beam, and the rubber pads are arranged at intervals along the longitudinal direction of the connection.

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