Shortening concrete bridge temperature across structure

Abstract

The utility model relates to bridge structure design technical field, concretely relates to a kind of shortening concrete bridge temperature span structure, the midspan longitudinal section of beam body is provided with joint, and the beam body of both sides of midspan can be moved along the bridge direction, midspan expansion joint is arranged at the position of joint, and when beam body is elongated or shrinks, midspan expansion joint realizes bridge direction expansion and contraction at midspan position.The utility model has the advantages that:1) the structure stress is optimized, and the concrete bridge temperature span is greatly shortened;2) the beam rail stress is greatly improved by shortening temperature span, and track temperature regulator is avoided, so as to save investment;Because not being equipped with track temperature regulator influence, the linear of long-span concrete bridge is no longer limited, and it is more favorable for the route selection of railway and rail transit;3) after shortening temperature span, the fixed support of middle support point is saved, and investment is saved;4) the main beam expansion caused by temperature can be eliminated by expansion device, and the bridge pier is not bent moment due to the temperature change of main beam, and pier beam consolidation is not affected by bridge pier height.

Description

Technical Field

[0001] This utility model relates to the field of bridge structure design technology, specifically to a structure for shortening the temperature span of a concrete bridge. Background Technology

[0002] With the development of high-speed railways and rail transit, the application of ballastless track bridges is increasing, resulting in a large number of long-span ballastless track bridges. However, ballastless tracks have high requirements for temperature spans.

[0003] like Figure 1 As shown, the temperature span of the existing continuous concrete beam extends from the fixed support to the beam end, i.e., the length L. If this length exceeds the normal temperature span, it can easily cause incoordination in the deformation of the beam and the ballastless track, requiring adjustment through a track temperature regulator. However, track temperature regulators are not only expensive, increasing project investment, but also have high requirements for track alignment. In fact, the inability to set track temperature regulators for long-span bridges can even affect the overall track alignment. Summary of the Invention

[0004] The purpose of this utility model is to address the shortcomings of the prior art by providing a structure that shortens the temperature span of concrete bridges. By setting longitudinal joints in the mid-span of the beam, the beams on both sides of the joint can move along the bridge direction. Bending moment and shear force are transmitted through mid-span expansion joints located at the joints, thus optimizing the structural stress and greatly shortening the temperature span of the concrete bridge. At the same time, it ensures that the deformation of the beam and the ballastless track are coordinated.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A structure for shortening the temperature span of a concrete bridge includes a main pier, side piers, and a beam. The beam is supported on the main pier and side piers. The beam includes a mid-span section and side-span sections. A ballastless track is installed above the beam. The beam is characterized by: a longitudinal joint is provided in the mid-span section of the beam to allow the beam on both sides of the mid-span section to move along the bridge direction; a mid-span expansion joint is provided at the location of the joint, and the mid-span expansion joint expands and contracts along the bridge direction at the mid-span position when the beam extends or contracts.

[0007] The mid-span expansion joint is installed on the top plate, bottom plate and web of the beam.

[0008] The mid-span telescopic device located on the top plate, the mid-span telescopic device located on the bottom plate, and the mid-span telescopic device located on the web plate are arranged on different elevations on both sides of the mid-span midline.

[0009] The mid-span expansion joint includes a first expansion member and a second expansion member, wherein the first expansion member is embedded in the beam near the end face on one side of the fracture, and the second expansion member is embedded in the beam near the end face on the other side of the fracture, and the first expansion member and the second expansion member are interlocked; an expansion joint is provided between the first expansion member and the beam on its opposite side, and an expansion joint is provided between the second expansion member and the beam on its opposite side.

[0010] The first telescopic member has the same structure as the second telescopic member, both of which have bending buckles and are connected by the cooperation between the bending buckles.

[0011] The first expansion joint and the second expansion joint are embedded in their respective beam bodies by pre-embedded parts.

[0012] The beam in the mid-span section is fixed to the main pier below it.

[0013] The beam of the side span is connected to the side pier below it by a longitudinally movable bearing.

[0014] The advantages of this utility model are:

[0015] 1) The structural stress was optimized, which greatly shortened the temperature span of the concrete bridge.

[0016] 2) Shortening the temperature span greatly improves the stress on the beam and rail, ensuring that the deformation of the beam and the ballastless track is coordinated without the need for a rail temperature regulator, thus saving investment; because there is no rail temperature regulator, the alignment of long-span concrete bridges is no longer restricted, which is more beneficial for railway and rail transit route selection.

[0017] 3) Shortening the temperature span saves on the fixed support at the middle support point, thus saving investment.

[0018] 4) Because there is an expansion joint in the mid-span of the bridge, the expansion and contraction of the main beam caused by temperature can be eliminated by the expansion joint, and the pier will not be affected by the temperature rise and fall of the main beam. The pier-beam connection is not affected by the height of the pier.

[0019] 5) The structure is simple and reasonable, and can be embedded into the beam during prefabrication, making construction convenient and suitable for widespread application. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the temperature span range of a large-span continuous concrete beam in the prior art;

[0021] Figure 2 This is a schematic diagram of the structure of the present invention (including the temperature range).

[0022] Figure 3 This is a mid-section elevation view of the present invention;

[0023] Figure 4 This is a mid-span plan view of the top plate of this utility model;

[0024] Figure 5 This is a mid-span elevation view of the top slab of this utility model;

[0025] Figure 6 This is a mid-span elevation view of the base plate of this utility model;

[0026] Figure 7 The bending moment diagram is shown for a large-span continuous concrete beam in the prior art.

[0027] Figure 8 This is the bending moment diagram of this utility model;

[0028] Figure 9 This is a schematic diagram showing the temperature span range and the expansion and contraction direction of the main beam in existing large-span concrete continuous beam structures.

[0029] Figure 10 This is a schematic diagram showing the temperature range and the direction of expansion and contraction of the main beam of this utility model. Detailed Implementation

[0030] The features and other related features of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate the understanding of those skilled in the art:

[0031] like Figure 1-10 As shown in the figure, the numbers 1-21 represent: 1. Main pier, 2. Beam body, 3. Pier-beam fixed joint, 4. Moving bearing along the bridge direction, 5. Temperature span, 6. Mid-span expansion joint, 7. Bottom plate, 8. Top plate, 9. Ballastless track, 10. Left top plate, 11. Right top plate, 12. Right side expansion joint, 13. Upper expansion joint, 14. Left side expansion joint, 15. Lower expansion joint, 16. Left bottom plate, 17. Right bottom plate, 18. Left side expansion joint, 19. Right side expansion joint, 20. Lower expansion joint, 21.

[0032] Example: Figures 1 to 10 As shown, the shortened temperature span structure of the concrete bridge in this embodiment includes a main pier 1 and a beam 2, wherein the beam 2 is supported on the main pier 1 and the side piers. The beam between the two main piers 1 is the mid-span section, and the beam between the main pier and the side pier is the side span section. A ballastless track 9 is installed above the beam 2.

[0033] like Figure 2As shown, in this embodiment, the main pier 1 and the beam 2 are fixed at the pier-beam connection point 3, and the beam 2 and the side pier are connected by a longitudinally movable bearing 4. A joint is provided at the mid-span, and a mid-span expansion joint 6 is installed at the joint. When the beam 2 deforms, for example, when the beam 2 elongates or contracts due to temperature deformation caused by temperature changes, the mid-span expansion joint 6 achieves longitudinal expansion at the mid-span position, thereby reducing the length of the temperature span 5. (Comparison) Figure 1 and Figure 2 It can be seen that the length of the temperature span 5 in this embodiment is significantly smaller than the temperature span length L in the prior art.

[0034] like Figure 3 As shown, the beam 2 includes a bottom plate 7, a top plate 8, and a web (not shown in the elevation view). Mid-span expansion joints 6 are provided on the bottom plate 7, the top plate 8, and the web to ensure that the entire beam 2 can expand and contract in the longitudinal direction.

[0035] Combination Figure 4 and Figure 5 As shown, taking the illustrated direction as an example, the top slab 8 of beam 2 is divided into a left top slab 10 and a right top slab 11 due to the presence of a fracture joint. The mid-span expansion joint 6 at the fracture joint location includes a right expansion member 12 and a left expansion member 14, serving as the first and second expansion members respectively. The right expansion member 12 is embedded in the right top slab 11 via pre-embedded parts, and the left expansion member 14 is embedded in the left top slab 10 via pre-embedded parts. The right expansion member 12 and the left expansion member 14 have identical structures, both equipped with bent buckles. These buckles engage to form a contact connection, allowing the right expansion member 12 and the left expansion member 14 to transmit bending moment and shear force after being tightly fastened. An upper expansion joint 13 is provided between the right expansion member 12 and the left top slab 10, ensuring free longitudinal displacement of both the right expansion member 12 and the right top slab 11. Similarly, a lower expansion joint 15 is left between the left expansion member 14 and the right top plate 11, which can ensure the free displacement of the left expansion member 14 and the left top plate 10 along the bridge direction, thereby ensuring the deformation coordination between the top plate 8 as a whole and the ballastless track 9 set above it.

[0036] like Figure 6 As shown, the base plate 7 is also divided into a left base plate 16 and a right base plate 17 by setting a joint. At the location of the joint, a left expansion joint 18 and a right expansion joint 19 are set, which transfer bending moment and shear force through interlocking. An upper expansion joint 21 is left between the right expansion joint 19 and the left base plate 16; a lower expansion joint 20 is left between the left expansion joint 18 and the right base plate 17 to ensure free longitudinal displacement of the expansion joints and the beam base plate.

[0037] Similarly, the same mid-span expansion joint 6 as the bottom plate 7 and top plate 8 is also installed at the web of beam 2 to ensure the free longitudinal displacement of the expansion joint and the beam as a whole.

[0038] In this embodiment, as Figure 3 As shown, the mid-span expansion joints 6, installed on the bottom plate 7 and the top plate 8, are arranged on different elevations on both sides of the centerline of the mid-span section of the beam 2, so that the stress points of the beam joint on both sides of the fracture are in different planes, ensuring the structural performance of the beam 2 and eliminating weak points. Similarly, the mid-span expansion joints 6 installed on the web of the beam are also located on different elevations.

[0039] contrast Figure 7 and Figure 8 As shown, in this embodiment, the fixed support between the main pier 1 and the beam 2 is eliminated and a fixed connection is adopted. Since the mid-span of the beam 2 can move along the bridge direction, the main pier 1 will not generate a bending moment due to the deformation of the beam 2. Therefore, the fixed connection point 3 between the pier and the beam does not have any requirements on the height of the main pier 1, which facilitates design and construction.

[0040] contrast Figure 9 and Figure 10 As shown, in the prior art, the fixed position of a long-span continuous concrete beam extends and contracts to both sides from the fixed support position, and the temperature span length extends from the fixed support to the beam end. However, in this embodiment, the beam 2 can extend and contracts to both sides from the main pier 1, and because a mid-span expansion joint 6 is set in the mid-span section, its temperature span is divided into either from the main pier 1 to the beam end or from the main pier 1 to the mid-span. In this way, the length of the temperature span is greatly shortened, and its effect will be more significant for multi-span continuous beams.

[0041] This embodiment includes the following steps in its design and construction:

[0042] 1) Based on the structural stress calculation, confirm the dimensions of the first and second expansion members of the mid-span expansion device 6, and ensure that the bending and shear strength of the first and second expansion members is not less than the original structural strength, and that there are no weak points at the component locations.

[0043] 2) The beam 2 and the main pier 1 are fixed at the pier-beam fixed point 3. The beam 2 is then cast in place or suspended to the last segment of the beam 2, with the closure section on both sides reserved.

[0044] 3) The first or second expansion member of the mid-span expansion device 6 is pre-embedded in the bottom plate 7, top plate 8 and web of the beam 2, and the two are locked together.

[0045] 4) Pour concrete around the mid-span expansion joint 6 (first expansion member and second expansion member), and stagger the reserved upper and lower expansion joints to complete the closure, ensuring that the bottom plate 7, top plate 8, web plate and each mid-span expansion joint 6 can change along the bridge direction, thereby optimizing the temperature span of the large-span concrete continuous beam.

[0046] 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 structure for shortening the temperature span of a concrete bridge, comprising a main pier, side piers, and a beam, wherein the beam is supported on the main pier and side piers, the beam comprising a mid-span section and a side-span section, and a ballastless track is provided above the beam, characterized in that: The beam body is longitudinally provided with a joint in the mid-span section so that the beam body on both sides of the mid-span section can move along the bridge direction. A mid-span expansion joint is provided at the location of the joint. When the beam body extends or contracts, the mid-span expansion joint realizes longitudinal expansion and contraction at the mid-span position. The mid-span expansion joint includes a first expansion member and a second expansion member, wherein the first expansion member is embedded in the beam near the end face on one side of the fracture, and the second expansion member is embedded in the beam near the end face on the other side of the fracture, and the first expansion member and the second expansion member are interlocked; an expansion joint is provided between the first expansion member and the beam on its opposite side, and an expansion joint is provided between the second expansion member and the beam on its opposite side.

2. The structure for shortening the temperature span of a concrete bridge according to claim 1, characterized in that: The mid-span expansion joint is installed on the top plate, bottom plate and web of the beam.

3. A structure for shortening the temperature span of a concrete bridge according to claim 2, characterized in that: The mid-span telescopic device located on the top plate, the mid-span telescopic device located on the bottom plate, and the mid-span telescopic device located on the web plate are arranged on different elevations on both sides of the mid-span midline.

4. A structure for shortening the temperature span of a concrete bridge according to claim 1, characterized in that: The first telescopic member has the same structure as the second telescopic member, both of which have bending buckles and are connected by the cooperation between the bending buckles.

5. A structure for shortening the temperature span of a concrete bridge according to claim 1, characterized in that: The first expansion joint and the second expansion joint are embedded in their respective beam bodies by pre-embedded parts.

6. A structure for shortening the temperature span of a concrete bridge according to claim 1, characterized in that: The beam in the mid-span section is fixed to the main pier below it.

7. A structure for shortening the temperature span of a concrete bridge according to claim 1, characterized in that: The beam of the side span is connected to the side pier below it by a longitudinally movable bearing.

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