Method for connecting a ballastless track steel beam top plate and a concrete bridge deck

Abstract

The present application relates to a kind of methods for connecting the slab of steel beam of ballastless track with concrete bridge deck, and the concrete bridge deck is disconnected with certain range joint along its bridge direction to form independent bridge deck panel, and the independent bridge deck panel is divided into fixed area, transition area and mobile area;Wherein, the strong connection is formed between the concrete bridge deck in fixed area and the slab of steel beam, the weak connection is formed between the concrete bridge deck in transition area and the slab of steel beam, and the weak connection refers to the connection allowing small deformation between the concrete bridge deck and the slab of steel beam;The filling connection is formed between the concrete bridge deck in mobile area and the slab of steel beam, and the filling connection refers to the connection allowing large horizontal deformation between the concrete bridge deck and the slab of steel beam.The advantages of the present application are: 1) the whole piece of bridge deck can be prefabricated to ensure the construction period;2) release the stress of concrete bridge deck along the bridge direction, reduce concrete cracking and reduce subsequent maintenance work;3) bridge deck block construction, convenient construction, less dependent on large machinery.

Description

Technical Field

[0001] This invention relates to the field of bridge technology, and in particular to a method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck. Background Technology

[0002] In recent years, steel box girders and steel-concrete composite beams have been widely used in railways. Especially with the development of high-speed railways, more and more ballastless track bridge structures are also adopting steel beams or steel-concrete composite beam structures, due to the requirements of the ballastless track structure, such as... Figure 1 and Figure 2 As shown, a layer of concrete bridge deck 3 needs to be laid on the top plate 2 of the steel box girder 1. After the construction of the steel box girder 1 is completed, concrete is poured on top of it, and the two are connected by shear studs 4 and shear keys.

[0003] The relationship between the concrete bridge deck 3 and the steel beam top plate 2 is as follows: Figure 3 As shown, the original length of both is L. (Comparison) Figure 3 and Figure 4 As shown, due to the shrinkage and creep during the pouring of the concrete bridge deck 3, if there were no shear studs 4, the length of the concrete bridge deck 3 would be L1 shorter than the length of the steel beam top plate 2. At the same time, due to the deformation difference between the concrete structure and the steel structure during operation, the length of the concrete bridge deck 3 would be L2 shorter than the length of the steel beam top plate 2.

[0004] At this point, due to the presence of shear studs 4 arranged along the bridge direction, the concrete bridge deck 3 needs to deform in tandem with the steel box girder 1 (steel beam top plate 2). Therefore, the concrete bridge deck 3 bears a tensile force F1 = A * E * (L1 + L2), where A is the area of ​​the concrete bridge deck 3, E is the elastic model of concrete, and L1 + L2 is the theoretically calculated length difference between the concrete bridge deck 3 and the steel beam top plate 2. The tensile force on the concrete bridge deck 3 causes cracking, affecting the structural safety performance and increasing the workload of rail transit operation and maintenance. For example, cracking of the bridge deck allows water to penetrate into the steel beam top plate 2, causing rust on the steel beam top plate 2, which in turn affects the structural safety. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck. By dividing the concrete bridge deck into sections and controlling the allowable deformation of each section, the tensile stress of the concrete slab caused by shrinkage and creep during concrete construction, as well as the tensile stress caused by the difference in deformation between the concrete structure and the steel structure during operation, can be reduced or eliminated, thereby reducing or avoiding cracking of the concrete bridge deck.

[0006] The objective of this invention is achieved through the following technical solutions:

[0007] A method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck includes a steel beam top plate of a steel box girder and a concrete bridge deck, characterized in that: the concrete bridge deck is broken into joints along its longitudinal direction within a certain range, dividing the concrete bridge deck into independent bridge decks, and each independent bridge deck is divided into a fixed area, a transition area and a movable area.

[0008] A strong connection is formed between the concrete bridge deck and the steel beam top plate in the fixed zone; a weak connection is formed between the concrete bridge deck and the steel beam top plate in the transition zone, wherein the weak connection means that a small deformation is allowed between the concrete bridge deck and the steel beam top plate; and a filling connection is formed between the concrete bridge deck and the steel beam top plate in the moving zone, wherein the filling connection means that a large horizontal deformation is allowed between the concrete bridge deck and the steel beam top plate.

[0009] The strong connection within the fixed area refers to the strong connection between the top plate of the steel beam and the concrete bridge deck formed by shear studs or shear keys.

[0010] The weak connection in the transition zone refers to the weak connection between the top plate of the steel beam and the concrete bridge deck formed by shear studs wrapped with an elastic body.

[0011] The filling connection within the moving area refers to the fact that the concrete bridge deck has holes, the top plate of the steel beam is provided with shear studs or shear keys, the shear studs or shear keys are located in the holes, and the holes are filled with filling material.

[0012] The fixed area, the transition area, and the movable area are arranged such that the transition area is arranged on both sides of the fixed area, and the movable area is arranged outside the transition area; the independent bridge deck is arranged along the longitudinal direction of the bridge in the above arrangement.

[0013] Along the bridge direction, the length of the fixed area is less than the length of the transition area, which is less than the length of the moving area.

[0014] A rubber joint is provided at the break point of the concrete bridge deck.

[0015] The steel box girder and the concrete bridge deck are constructed using the cast-in-place method on the top of the girder. Shear studs are installed on the top plate of the steel girder, and an elastic shell is wrapped around the outside of the shear studs in the moving area. The concrete bridge deck is cast in place on the steel box girder, and elastic material is injected into the elastic shell.

[0016] The steel box girder and the concrete bridge deck are constructed using a prefabrication method. Shear studs are installed on the top plate of the steel girder. Holes matching the shear studs are reserved during the prefabrication of the concrete bridge deck. After shrinkage and creep are completed, the concrete bridge deck is fitted onto the shear stud positions. Grouting is performed in the fixed area, and elastic material is injected in the moving area.

[0017] The steel box girder and the concrete bridge deck are constructed using a combination of prefabrication and cast-in-place methods. Shear studs are installed on the top plate of the steel girder, and the concrete bridge decks for the transition and moving zones are prefabricated. The prefabricated concrete bridge decks are then fitted onto the shear studs, and the concrete bridge decks for the fixed zone are poured to form a whole.

[0018] The advantages of this invention are:

[0019] 1) It allows for the prefabrication of bridge deck panels in whole pieces, ensuring the construction period;

[0020] 2) Relieves longitudinal stress in the concrete bridge deck, reduces concrete cracking, and reduces subsequent maintenance work;

[0021] 3) The bridge deck is constructed in sections, which is convenient and requires less reliance on large machinery. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a steel box girder structure in the prior art;

[0023] Figure 2 This is a schematic diagram of the connection structure between a steel box girder and a concrete bridge deck in the prior art.

[0024] Figure 3 This is a diagram illustrating the relationship between concrete bridge decks and steel box girders in existing technologies.

[0025] Figure 4 This is a schematic diagram of the deformation of concrete bridge deck and steel box girder in the prior art;

[0026] Figure 5 This is a schematic diagram of the stress on concrete bridge decks and steel box girders in the existing technology.

[0027] Figure 6 This is a schematic elevation view of the joint of the concrete bridge deck according to the present invention;

[0028] Figure 7 This is a schematic diagram of the joint plan of the concrete bridge deck according to the present invention;

[0029] Figure 8 This is a schematic diagram of the partitioned plan of the concrete bridge deck according to the present invention;

[0030] Figure 9 This is a schematic diagram of the partitioned elevation of the concrete bridge deck of the present invention;

[0031] Figure 10 This is a planar schematic diagram of the fixed area in this invention;

[0032] Figure 11 This is a schematic elevation view of the transition zone in this invention;

[0033] Figure 12 This is a schematic elevation view of the moving area in this invention;

[0034] Figure 13 This is a schematic diagram of the first construction method of the present invention;

[0035] Figure 14 This is a schematic diagram of the second construction method of the present invention;

[0036] Figure 15 This is a schematic diagram of the third construction method of the present invention. Implementation

[0037] The features and other related features of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate understanding by those skilled in the art:

[0038] like Figure 1-15 As shown in the figure, markings 1-19 represent: 1. Steel box girder, 2. Steel box girder top plate, 3. Concrete bridge deck, 4. Shear stud, 5. Track structure, 6. Steel box girder, 7. Concrete bridge deck, 8. Joint, 9. Fixed zone, 10. Transition zone, 11. Moving zone, 12. Steel beam top plate, 13. Shear stud, 14. Elastic outer material, 15. Elastic filling material, 16. Shear stud tensile cap, 17. Precast bridge deck, 18. Reserved hole, 19. Cement mortar.

[0039] Example: Figures 6 to 15 As shown, the connection method between the top plate of the ballastless track steel beam and the concrete bridge deck in this embodiment is used to realize the connection between the steel box girder 6 and the concrete bridge deck 7. It can reduce or eliminate the tensile stress of the concrete slab caused by shrinkage and creep during concrete construction and the tensile stress caused by the difference in deformation between the concrete structure and the steel structure during operation, thereby reducing or avoiding the occurrence of cracking of the concrete bridge deck.

[0040] Specifically, such as Figure 6 and Figure 7 As shown, the concrete bridge deck 7 in this embodiment adopts a partitioned structural design. The deformation length of the concrete bridge deck is reduced by setting the joint 8. That is, the bridge deck is divided by breaking the entire bridge deck in the longitudinal direction to form the joint 8, and rubber joints are set at the position of the joint 8 to ensure that the longitudinal deformation of the bridge decks is not affected by each other, forming independent bridge decks in the longitudinal direction.

[0041] At this point, the tensile force F on the original monolithic concrete bridge deck 7 is proportional to its length L. However, in order to reduce the tensile force, the joints are broken to form independent bridge decks along the bridge direction. The tensile force on each independent bridge deck becomes proportional to its length L3. Therefore, the tensile force on the independent concrete bridge deck is reduced.

[0042] like Figure 8 As shown, the deformation length range of each independent bridge deck after the fracture 8 is L3. Within the length range L3 of this independent bridge deck, there are three zones: a fixed zone 9, a transition zone 10, and a moving zone 12. The middle of the independent bridge deck is the fixed zone 9, in which the concrete bridge deck and the steel beam top plate 12 have no longitudinal displacement. The two sides of the fixed zone 9 are symmetrically arranged with transition zones 10, in which the concrete bridge deck and the steel beam top plate 12 have limited displacement and can move relative to each other when the stress difference between them is large. The outer sides of the transition zones 10 are arranged with moving zones 12, in which the concrete bridge deck and the steel beam top plate 12 can move freely longitudinally.

[0043] In this embodiment, as Figure 8 As shown, within each independent bridge deck panel, the length of the fixed zone 9 is the minimum, L7. Therefore, for each independent bridge deck panel, the tensile length of the concrete slab is further optimized from L3 to L7. The longitudinal horizontal force of each bridge deck panel is mainly borne by the fixed zone 9 alone, which is sufficient to meet the force requirements. Due to the movement of the shear studs, the transition zone 10 and the moving zone 11 can release the displacement of these two zones, preventing the bridge deck from being tensile due to the free movement of these two zones. At the same time, during the movement, the rubber joints between the fracture joints 8 are squeezed or stretched, further releasing the displacement.

[0044] Combination Figure 9 and Figure 10 As shown, within the fixed zone 9, the concrete bridge deck 7 and the steel beam top plate 12 are strongly connected by shear studs 13, thus fixing the concrete bridge deck 7 and the steel beam top plate 12 together, preventing longitudinal displacement between them. Figure 10 As shown, the shear studs 13 are arranged in a uniform array to ensure the fixed connection performance between the concrete bridge deck 7 and the steel beam top plate 12.

[0045] Combination Figure 9 and Figure 11 As shown, within the transition zone 10, the concrete bridge deck 7 and the steel beam top plate 12 are weakly connected by shear studs 13 or shear keys wrapped with an elastic outer material 14. The "weakness" of this weak connection means that the concrete bridge deck 7 and the steel beam top plate 12 can undergo minor deformation through the elastic outer material 14; that is, when there is minor deformation, the elastic outer material 14 is compressed or stretched, allowing relative movement between the shear studs 13 or shear keys and the concrete, releasing some of the deformation.

[0046] In this embodiment, the elastic outer material 14 only wraps around a localized area of ​​the shear stud 13 or shear key. Figure 11 For example, the elastic outer material 14 is partially wrapped under the head of the shear stud 13 and does not exceed the range of the head. This ensures that the small deformation allowed in the transition zone 10 is still controlled, thus making the released deformation controlled.

[0047] Combination Figure 9 and Figure 12 As shown, within the moving zone 11, the concrete bridge deck 7 has large holes that surround the shear studs 13 or shear keys and are filled with elastic filler material 15, thereby allowing for greater horizontal deformation between the concrete bridge deck 7 and the steel beam top plate 12, releasing a relatively larger portion of the deformation compared to the transition zone 10.

[0048] In this embodiment, a shear nail tensile cap 16 is provided on the top of the shear nail 13 in the moving area 11. The shear nail tensile cap 16 extends along the bridge direction and into the concrete slab, which can limit the elastic filling material 15 and ensure that the elastic filling material 15 will not lift off the bridge deck. At the same time, it can also ensure that the elastic filling material 15 and the concrete slab share the force.

[0049] This embodiment significantly reduces the occurrence of cracks in concrete bridge decks by reducing the tensile length of the concrete slab and using a step-by-step deformation release method, first releasing most of the deformation on both sides and then releasing a small portion of the deformation.

[0050] This embodiment can be implemented using the following construction methods:

[0051] 1) Cast-in-place method:

[0052] like Figure 13 As shown, after welding shear studs 13 onto the top plate 12 of the steel beam, an elastic outer shell is wrapped around the outside of the shear studs 13 in the moving zone 11 to reserve space for the filling of the elastic filling material 15; the elastic outer shell material 14 around the shear studs in the transition zone 10 can be installed on-site or prefabricated during the manufacturing of the shear studs. A concrete bridge deck is cast in place on the steel beam. The elastic filling material 15 is injected into the elastic outer shell.

[0053] 2) Prefabrication method:

[0054] like Figure 14 As shown, the concrete bridge deck adopts a prefabrication process and is prefabricated as a prefabricated bridge deck 17. The deck has reserved holes 18 that match the shear studs. After the deck has completed shrinkage and creep, the prefabricated bridge deck 17 is fitted onto the shear studs 13. Cement mortar 19 is used to seal the reserved holes 18 and shear studs in the fixed area 9 and the transition area 10. Elastic filling material 15 is injected into the moving area 11.

[0055] 3) Combined precast and cast-in-place method:

[0056] like Figure 15 As shown, after prefabricating the bridge deck of the transition zone 10 and the moving zone 11, the bridge deck is placed on the shear studs, and the concrete of the fixed zone 9 is poured to form a whole. The reserved holes 18 in the fixed zone 9 and the transition zone 10 are sealed with cement mortar 19, and elastic filler material 15 is injected into the moving zone 11.

[0057] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck, comprising a steel beam top plate of a steel box girder and a concrete bridge deck, characterized in that: The concrete bridge deck is divided into independent bridge decks by a certain range along the bridge direction. Each independent bridge deck is divided into a fixed area, a transition area and a movable area. A strong connection is formed between the concrete bridge deck and the steel beam top plate in the fixed zone; a weak connection is formed between the concrete bridge deck and the steel beam top plate in the transition zone, wherein the weak connection allows for minor deformation between the concrete bridge deck and the steel beam top plate; and a filling connection is formed between the concrete bridge deck and the steel beam top plate in the moving zone, wherein the filling connection allows for larger horizontal deformation between the concrete bridge deck and the steel beam top plate. The strong connection within the fixed area refers to the strong connection between the top plate of the steel beam and the concrete bridge deck formed by shear studs or shear keys. The weak connection in the transition zone refers to the weak connection between the top plate of the steel beam and the concrete bridge deck formed by shear studs wrapped with an elastic body. The filling connection within the moving area refers to the following: the concrete bridge deck has holes, the top plate of the steel beam is provided with shear studs or shear keys, the shear studs or shear keys are located in the holes, and the holes are filled with filling material. The fixed area, the transition area, and the movable area are arranged such that the transition area is arranged on both sides of the fixed area, and the movable area is arranged outside the transition area; the independent bridge deck is arranged along the longitudinal direction of the bridge in the above arrangement.

2. The method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck according to claim 1, characterized in that: Along the bridge direction, the length of the fixed area is less than the length of the transition area, which is less than the length of the moving area.

3. The method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck according to claim 1, characterized in that: A rubber joint is provided at the break point of the concrete bridge deck.

4. The method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck according to claim 1, characterized in that: The steel box girder and the concrete bridge deck are constructed using the cast-in-place method on the top of the girder. Shear studs are installed on the top plate of the steel girder, and an elastic shell is wrapped around the outside of the shear studs in the moving area. The concrete bridge deck is cast in place on the steel box girder, and elastic material is injected into the elastic shell.

5. The method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck according to claim 1, characterized in that: The steel box girder and the concrete bridge deck are constructed using a prefabrication method. Shear studs are installed on the top plate of the steel girder. Holes matching the shear studs are reserved during the prefabrication of the concrete bridge deck. After shrinkage and creep are completed, the concrete bridge deck is fitted onto the shear stud positions. Grouting is performed in the fixed area, and elastic material is injected in the moving area.

6. The method for connecting the top plate of a ballastless track steel beam to a concrete bridge deck according to claim 1, characterized in that: The steel box girder and the concrete bridge deck are constructed using a combination of prefabrication and cast-in-place methods. Shear studs are installed on the top plate of the steel girder, and the concrete bridge decks for the transition and moving zones are prefabricated. The prefabricated concrete bridge decks are then fitted onto the shear studs, and the concrete bridge decks for the fixed zone are poured to form a whole.

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