Longitudinal continuous structure and construction method of bridge deck in negative bending moment zone of simply supported steel-concrete composite beam

Abstract

The present invention belongs to the field of bridge construction, and specifically relates to a longitudinal continuous structure and construction method for a simply supported steel-concrete composite beam bridge deck in the negative bending zone. It comprises a positive bending zone bridge deck, a steel beam, a negative bending zone concrete connecting plate, a shear connector, a non-bonded structure, a cap beam, longitudinal reinforcement in the negative bending zone, and longitudinal reinforcement in the positive bending zone. The positive bending zone bridge deck and the steel beam form a combined structure to bear the load together. The negative bending zone concrete connecting plate is made of high-performance concrete and spans above two adjacent steel beams, releasing the constraints between the steel beam and the bridge deck through a non-bonded structure. The negative bending zone concrete connecting plate is connected to the steel beam at the bonding section via a shear connector, and is separated and debonded between the non-bonded section and the steel beam using waterproof materials such as felt. The present invention reduces the stiffness of the continuous section by releasing the constraints between the bridge deck and the steel beam at the support, thereby reducing the stress of the bridge deck in the negative bending zone and improving the durability and driving comfort of the bridge.

Description

Technical Field

[0001] The invention belongs to the field of bridge construction, and in particular relates to a longitudinal continuous structure of a bridge deck in a negative bending moment zone of a simply supported steel-concrete composite beam and a construction method. Background Art

[0002] Simply supported steel-concrete composite beam bridges are a widely used type of small- to medium-span bridge in my country. However, these bridges must incorporate expansion joints, which present numerous disadvantages, including complex construction, poor driving comfort, and high maintenance costs. Traditionally, simply supported-to-continuous steel-concrete composite beams offer a solution to overcome the disadvantages of expansion joints. However, simply supported-to-continuous beam bridges utilize a continuous full-section structure, essentially a continuous beam bridge with high cross-sectional stiffness and negative bending moments, often leading to cracking in the concrete deck. Furthermore, the simply supported-to-continuous structure is complex, requiring cumbersome construction steps and requiring significant effort.

[0003] High-performance concrete (HSC) is a concrete suitable for industrial production and construction, centered on sustainable development and durability. It represents the future of concrete technology. High-performance concrete is characterized by high durability, excellent workability, and high strength. The most important technical means of achieving high performance in concrete is the use of composite superplasticizers and ultrafine mineral admixtures. Compared to conventional concrete, HSC has a higher raw material content, resulting in greater uniformity, density, and improved performance.

[0004] Chinese patent CN210712557U discloses a UHPC-treated steel-concrete composite structure in the negative moment zone. This structure uses an ultra-high performance concrete (UHPC) bridge deck within the negative moment section, with the upper flange of the steel beam welded (bolted) at the pier top. This connection is a rigid connection that uses the high strength of UHPC to resist cracking, but it does not actually improve the stress conditions of the bridge deck in the negative moment zone. Excessive restraint can cause stress concentration and support voiding. Summary of the Invention

[0005] The purpose of the present invention is to provide a longitudinal continuous structure of a concrete bridge deck in the negative bending moment area of ​​a simply supported steel-concrete composite beam, which reduces the stiffness of the continuous section by releasing the constraints between the steel beam and the bridge deck, thereby achieving the purpose of reducing the stress on the bridge deck cross section in the negative bending moment area. Furthermore, while satisfying the continuous function of the bridge deck, the continuous structure and construction are simplified, the crack resistance of the bridge deck is improved, and driving comfort is enhanced.

[0006] The technical solution for achieving the object of the present invention is: a longitudinal continuous structure of a simply supported steel-concrete composite beam moment zone concrete bridge deck, characterized by comprising a positive moment zone bridge deck, a steel beam, a negative moment zone concrete connecting plate, a shear connector, a non-combined structure, a cap beam, negative moment zone longitudinal reinforcement and positive moment zone longitudinal reinforcement;

[0007] The concrete connecting plate in the negative bending moment zone consists of a non-bonding section and bonding sections located on both sides of the non-bonding section. The concrete connecting plate spans above two adjacent steel beams and is connected to the steel beams at the bonding sections on both sides. The constraint between the concrete connecting plate and the steel beams is released at the non-bonding section.

[0008] Furthermore, the concrete connecting plate in the negative bending moment area is made of high-performance concrete material.

[0009] Furthermore, the length of the concrete connecting plate in the negative bending moment zone is L1, the length of the non-bonded section is L2, and the length of the bonded section is (L1-L2) / 2; the length L2 of the non-bonded section is greater than the distance between the two steel beams.

[0010] Furthermore, the concrete connecting plate in the negative bending moment area is connected between the joint section and the steel beam via a shear connector;

[0011] The negative bending moment area concrete connecting plate is provided with a non-bonded structure for separation and debonding between the non-bonded section and the steel beam.

[0012] Furthermore, the shear connector is a bolt, a steel section, or a perforated steel plate.

[0013] Furthermore, the non-bonded structure is linoleum or other waterproof materials.

[0014] Furthermore, the concrete connecting plate in the negative bending moment area and the bridge deck in the positive bending moment area are connected by cast-in-situ method;

[0015] Alternatively, the concrete connecting plate in the negative bending moment area and the bridge deck in the positive bending moment area are connected in a prefabricated manner, that is, the non-connected section adopts a prefabricated plate and the connected section adopts a cast-in-place joint.

[0016] Furthermore, the longitudinal steel bars in the negative bending moment area and the longitudinal steel bars in the positive bending moment area are connected at the connecting section of the concrete connecting plate in the negative bending moment area.

[0017] Furthermore, the cap beam is an exposed cap beam.

[0018] Furthermore, the cap beam may be a concealed cap beam, and a cushion layer is provided between the concrete connecting plate in the negative bending moment area and the top of the concealed cap beam.

[0019] A construction method of the above-mentioned continuous structure comprises the following steps:

[0020] Step (1): pre-embed shear connectors in the top plate of the steel beam;

[0021] Step (2): erecting steel beams to form a simply supported steel beam structure;

[0022] Step (3): installing the positive bending moment area concrete bridge deck, so that the positive bending moment area concrete bridge deck forms a combined structure with the simply supported steel beam structure of step (2) through shear connectors;

[0023] Step (4): Arrange a non-bonded structure at a position corresponding to the non-bonded section of the concrete connecting plate in the negative bending moment area on the top surface of the steel beam of the composite structure to separate and debond; for the concealed cap beam, a cushion layer needs to be provided on the top of the concealed cap beam;

[0024] Step (5): For the form of cast-in-place connection, tie the longitudinal steel bars in the negative bending moment area and cast the concrete connection plate in the negative bending moment area; for the form of prefabricated connection, first hoist the prefabricated plate in the non-bonding section of the negative bending moment area, and then cast the wet joint at the bonding section.

[0025] Compared with the prior art, the present invention has the following significant advantages:

[0026] The present invention reduces the stiffness of the continuous section by releasing the constraints on the bridge deck and steel beams in the negative bending moment area at the supports, thereby greatly reducing the stress of the bridge deck in the negative bending moment area. At the same time, the use of high-performance concrete as the material of the connecting section further improves the stress performance of the bridge deck in the negative bending moment area, can effectively avoid the development of cracks, and improve the durability of the bridge and driving comfort.

[0027] The present invention is applicable to solutions in which the lower structure is an exposed cap beam or a concealed cap beam, and the concrete connecting plate in the negative bending moment zone can be cast in situ or prefabricated. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a schematic diagram of the longitudinal continuous structure of the concrete bridge deck in the negative bending moment zone of the steel-concrete composite beam suitable for the exposed cap beam.

[0029] Figure 2 This is a schematic diagram of the longitudinal continuous structure of the concrete bridge deck in the negative bending moment area of ​​the steel-concrete composite beam used for the concealed cap beam of the present invention.

[0030] Description of reference numerals:

[0031] 1-bridge deck in positive bending moment zone, 2-steel beam, 3-concrete connecting plate in negative bending moment zone, 4-shear connector, 5-non-combined structure, 6-cap beam, 7-longitudinal reinforcement in negative bending moment zone, 8-longitudinal reinforcement in positive bending moment zone. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below with reference to the accompanying drawings.

[0033] In the mid-span positive bending moment section, the steel beam and concrete deck form a combined cross-section that bears the load together. In the negative bending moment section at the supports, the concrete connecting plate in the negative bending zone spans over the steel beam. This invention relieves the constraints between the steel beam and concrete deck by providing a non-bonded section in the negative bending moment zone, reducing stiffness in the negative bending moment zone and improving the load-bearing characteristics of the deck in this area.

[0034] A negative bending moment zone bridge deck connection structure suitable for a continuous bridge deck simply supported beam bridge with steel-concrete composite plate beams comprises a positive bending moment zone bridge deck 1, a steel beam 2, a negative bending moment zone concrete connection plate 3, a shear connector 4, a non-combined structure 5, a cap beam 6, negative bending moment zone longitudinal reinforcement 7 and positive bending moment zone longitudinal reinforcement 8.

[0035] The concrete connecting plate 3 in the negative bending moment area adopts high-performance concrete to improve the crack resistance and durability of the bridge deck in the negative bending moment area.

[0036] The concrete connecting plate 3 in the negative bending moment zone is divided into a bonding section and a non-bonding section. The bonding section and the steel beam are connected with shear connectors, and the gap is filled with sealing rubber strips; waterproof membranes such as tarpaulin are laid between the non-bonding section and the steel beam to separate and debond.

[0037] The concrete connecting plate 3 in the negative bending moment area is connected to the bridge deck 1 in the positive bending moment area by a cast-in-place method or a prefabricated method. When the prefabricated method is adopted, the non-joined section is a prefabricated plate and the joined section is a cast-in-place joint.

[0038] The cap beam 6 can be an exposed cap beam or a concealed cap beam. When the concealed cap beam solution is adopted, a cushion layer is provided between the concrete connecting plate 3 in the negative bending moment area and the concealed cap beam.

[0039] The longitudinal reinforcement 7 in the negative bending moment area and the longitudinal reinforcement 8 in the positive bending moment area are connected at the joint section of the concrete connecting plate in the negative bending moment area.

[0040] A method for constructing a continuous structure of a bridge deck in a negative bending moment zone of a steel-concrete composite slab girder bridge comprises the following steps:

[0041] Step 1: pre-embed shear connectors on the top plate of the steel beam at the junction of the positive bending moment zone and the negative bending moment zone, and lay waterproof materials such as tarpaulin on the top plate of the steel beam at the non-junction section of the negative bending moment zone;

[0042] Step 2: hoisting the steel beam 2 and the positive moment zone bridge deck 1 to form a composite section;

[0043] Step 3: If the cap beam is a concealed cap beam, a cushion layer is provided on the top surface of the concealed cap beam;

[0044] Step 4: tie the steel bars in the negative bending moment area and cast the concrete connecting plate 3 in the negative bending moment area. For prefabricated connection, first hoist the prefabricated plate in the non-joined section of the negative bending moment area, and then cast the wet joint at the joint section.

[0045] Example 1

[0046] Combine Figure 1 , provides a new type of continuous structure of the bridge deck in the negative bending moment area of ​​a steel-concrete composite slab girder bridge. It includes a bridge deck 1 in the positive bending moment area, a steel beam 2, a concrete connecting plate 3 in the negative bending moment area, a shear connector 4, a non-bonded structure 5, an exposed cap beam 6, longitudinal reinforcement 7 in the negative bending moment area and longitudinal reinforcement 8 in the positive bending moment area. The bridge deck 1 in the positive bending moment area and the steel beam 2 form a combined structure. The concrete connecting plate 3 in the negative bending moment area spans over two steel beams. The concrete connecting plate 3 in the negative bending moment area is made of high-performance concrete material. The concrete connecting plate 3 in the negative bending moment area is divided into a bonding section and a non-bonding section, which is connected to the steel beam through a shear connector. Waterproof materials such as tarpaulin are laid between the non-bonding section and the steel beam for separation, debonding and sealing.

[0047] Furthermore, the concrete connecting plate in the negative bending moment zone can be constructed by prefabrication or cast-in-place.

[0048] Furthermore, the longitudinal reinforcement 7 in the negative bending moment zone needs to be configured according to calculations, and the connection of the longitudinal reinforcement can adopt the currently commonly used form.

[0049] Example 2

[0050] Combine Figure 2 , provides a new type of continuous structure of the bridge deck in the negative bending moment area of ​​a steel-concrete composite slab girder bridge. It includes a bridge deck in the positive bending moment area 1, a steel beam 2, a concrete connecting plate in the negative bending moment area 3, a shear connector 4, a non-bonded structure 5, a concealed cover beam 6, longitudinal reinforcement in the negative bending moment area 7 and longitudinal reinforcement in the positive bending moment area 8. The bridge deck in the positive bending moment area 1 and the steel beam 2 form a combined structure. The concrete connecting plate 3 in the negative bending moment area spans above two steel beams. The concrete connecting plate 3 in the negative bending moment area is made of high-performance concrete material. The concrete connecting plate 3 in the negative bending moment area is divided into a bonding section and a non-bonding section, which is connected to the steel beam through a shear connector. Waterproof materials such as felt are laid between the non-bonding section and the steel beam for separation, debonding and sealing.

[0051] Furthermore, a cushion layer is provided between the top of the concealed cap beam 6 and the bottom of the concrete connecting plate 3 in the negative bending moment area.

[0052] Furthermore, the concrete connecting plate in the negative bending moment zone can be constructed by prefabrication or cast-in-place.

[0053] Furthermore, the longitudinal reinforcement 7 in the negative bending moment zone needs to be configured according to calculations, and the connection of the longitudinal reinforcement can adopt the currently commonly used form.

[0054] By releasing the partial constraints of the concrete slab and steel beam in the negative bending moment area, the internal force distribution in the negative bending moment area is improved and the maximum tensile stress of the concrete slab in the negative bending moment area is reduced.

Claims

1. A longitudinal continuous structure of a concrete bridge deck in the bending zone of a simply supported steel-concrete composite beam, characterized in that: It includes a bridge deck in a positive bending moment area (1), a steel beam (2), a concrete connecting plate in a negative bending moment area (3), a shear connector (4), a non-combined structure (5), a cap beam (6), longitudinal reinforcement in a negative bending moment area (7), and longitudinal reinforcement in a positive bending moment area (8); The negative bending moment area concrete connecting plate (3) is composed of a non-bonded section and bonded sections located on both sides of the non-bonded section. The negative bending moment area concrete connecting plate (3) is arranged above two adjacent steel beams (2), and the bonded sections on both sides are connected to the steel beams (2). The constraint between the negative bending moment area concrete connecting plate (3) and the steel beams (2) is released at the non-bonded section. The length of the concrete connecting plate (3) in the negative bending moment zone is L1, the length of the non-bonded section is L2, and the length of the bonded section is (L1-L2) / 2; the length L2 of the non-bonded section is greater than the distance between the two steel beams (2); The negative moment zone concrete connecting plate (3) is connected between the joint section and the steel beam (2) via a shear connector (4); The concrete connecting plate (3) in the negative bending moment zone is provided with a non-bonded structure (5) between the non-bonded section and the steel beam (2) to separate and debond; The shear connector (4) is a stud, a steel section, or a perforated steel plate; The non-bonded structure (5) is made of linoleum or other waterproof materials.

2. The longitudinal continuous structure of the concrete bridge deck in the bending zone of the simply supported steel-concrete composite beam according to claim 1 is characterized in that: The negative moment zone concrete connecting plate (3) is made of high-performance concrete material.

3. The longitudinal continuous structure of the concrete bridge deck in the bending zone of the simply supported steel-concrete composite beam according to claim 1 is characterized in that: The negative bending moment area concrete connecting plate (3) and the positive bending moment area bridge deck (1) are connected in a cast-in-situ manner; Alternatively, a prefabricated connection method is adopted between the negative bending moment area concrete connecting plate (3) and the positive bending moment area bridge deck (1), that is, the non-joined section adopts a prefabricated plate and the joined section adopts a cast-in-place joint.

4. The longitudinal continuous structure of the concrete bridge deck in the bending zone of the simply supported steel-concrete composite beam according to claim 1 is characterized in that: The negative bending moment zone longitudinal steel bars (7) and the positive bending moment zone longitudinal steel bars (8) are connected at the connecting section of the negative bending moment zone concrete connecting plate (3).

5. The longitudinal continuous structure of the concrete bridge deck in the bending zone of the simply supported steel-concrete composite beam according to claim 1 is characterized in that: The cap beam (6) is an exposed cap beam; Alternatively, the cap beam (6) may be a concealed cap beam, and a cushion layer may be provided between the negative bending moment zone concrete connecting plate (3) and the top of the concealed cap beam.

6. A construction method for a continuous structure according to any one of claims 1 to 5, characterized in that: The steps include: Step (1): pre-embed the shear connector (4) in the top plate of the steel beam (2); Step (2): erecting the steel beam (2) to form a simply supported steel beam structure; Step (3): installing the positive bending moment area bridge deck (1), so that the positive bending moment area bridge deck (1) forms a combined structure with the simply supported steel beam structure of step (2) through the shear connector (4); Step (4): Arrange a non-bonded structure (5) at a position corresponding to the non-bonded section of the top surface of the steel beam (2) of the composite structure and the concrete connecting plate (3) in the negative bending moment area to separate and debond; for the concealed cap beam, a cushion layer needs to be provided on the top of the concealed cap beam; Step (5): For the form of cast-in-place connection, tie the longitudinal steel bars (7) in the negative bending moment area and cast the concrete connection plate (3) in the negative bending moment area; for the form of prefabricated connection, first hoist the prefabricated plate in the non-joined section of the negative bending moment area and then cast the wet joint at the joined section.

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