Transverse widening connection structure and construction method for longitudinally sliding continuous beam bridge

Abstract

This invention discloses a longitudinally sliding continuous beam bridge transverse widening connection structure and construction method, including a groove formed within the flange of the new bridge with its opening facing the flange of the old bridge; a circular channel steel located within the groove with its opening facing the flange of the old bridge; an arc-shaped sliding plate located on the inner side of the circular channel steel to reduce friction; a solid circular steel pipe located on the inner side of the arc-shaped sliding plate; transverse connecting steel bars wound around the outer surface of the solid circular steel pipe with one end embedded in the flange of the old bridge; a vertical sliding plate vertically attached to the end face of the new bridge flange to reduce friction; and a steel plate vertically attached to the end face of the old bridge flange, wherein the vertical sliding plate and the steel plate are in close contact with each other. In this invention, the solid circular steel pipe can slide longitudinally within the circular channel steel, and the arc-shaped sliding plate reduces friction, providing better longitudinal bridge sliding deformation. This fundamentally solves the problem of excessive transverse bending deformation caused by the difference in longitudinal deformation between the new and old bridges, leading to cracking and damage of the widening structure.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a longitudinally sliding continuous beam bridge transverse widening connection structure and construction method. Background Technology

[0002] Most highways built in the past were four-lane highways in both directions, and a significant portion of these highways are now experiencing insufficient capacity, leading to traffic congestion. Considering the increasing scarcity of land resources and the rising cost of building new highways, widening and upgrading existing highways has become a win-win solution. Currently, in the widening projects of concrete continuous beam bridges in China, traditional hinged wet joint connection structures are widely used for the transverse connection between the old and new bridges. However, when applied to the widening of long-span concrete continuous beam bridges, the significant difference in longitudinal shrinkage and creep between the old and new bridges causes severe transverse deformation at the ends of the widened structure, compressing the seismic blocks and causing damage. Therefore, it is urgent to explore effective solutions to overcome these technical bottlenecks.

[0003] To address the aforementioned issues, existing technology (CN115075114A) proposes a transverse widening connection structure for a longitudinally deformable concrete continuous box girder. In this structure, one end of the transverse connecting reinforcement is pre-embedded in the flange of the old box girder, and the other end is welded to the transverse reinforcement in the flange of the new box girder. The gap between the elliptical transverse steel pipe and the transverse connecting reinforcement is filled with foam. Elliptical holes in the longitudinally perforated steel plate are also distributed longitudinally to allow the elliptical transverse steel pipe to pass through. Finally, the concrete for the flange of the new box girder and the transverse joint is poured and cured to form the transverse widening structure. While this structure allows the new bridge to undergo longitudinal shrinkage deformation to a certain extent, it also presents some unavoidable problems, such as:

[0004] (1) Since the cast-in-place concrete between the new and old bridge flanges completely binds the two together, when the new bridge shrinks in the longitudinal direction, although most of the deformation is absorbed by the gap between the elliptical transverse steel pipe and the transverse embedded steel bar, it cannot be completely absorbed. There will still be a longitudinal displacement difference between the new and old bridge flanges where there is no elliptical steel pipe and transverse embedded steel bar. This will cause longitudinal cracks to appear on the surface of the cast-in-place concrete along the contact part of the new and old bridge flanges. This situation will be more obvious when facing the widening of long-span concrete continuous beam bridges.

[0005] (2) The foam material filling the gap between the elliptical steel pipe and the transverse connecting steel bar is used because the bridge will continue to operate for several decades after the bridge is widened. The foam material may age and harden and lose its function. Furthermore, the structure does not take into account the situation of replacing the foam later, so it cannot be replaced.

[0006] (3) The transverse pre-embedded steel bars in the new bridge and the old bridge are connected into a whole by welding to share the force. After the bridge is widened, when resisting the vertical shearing action caused by the settlement of the new bridge and vehicle load, stress concentration is likely to occur at the weld. Moreover, the cross-sectional size of the transverse steel bars is small, and the maximum tensile force that the weld can withstand is small, which may lead to breakage, thus greatly reducing the vertical shear resistance of the structure.

[0007] Therefore, the above problems urgently need to be solved. Summary of the Invention

[0008] Purpose of the invention: The first objective of this invention is to provide a longitudinally sliding continuous beam bridge transverse widening connection structure with good lateral tensile strength and vertical shear strength.

[0009] The second objective of this invention is to provide a construction method for a longitudinally sliding continuous beam bridge with a transversely widened connection structure.

[0010] Technical Solution: To achieve the above objectives, this invention discloses a longitudinally slidable continuous beam bridge transverse widening connection structure, comprising a groove formed in the new bridge flange plate with its opening facing the old bridge flange plate, a circular channel steel located in the groove with its opening facing the old bridge flange plate, an arc-shaped sliding plate located on the inner side of the circular channel steel for reducing friction, a solid circular steel pipe located on the inner side of the arc-shaped sliding plate, a transverse connecting steel bar wound around the outer surface of the solid circular steel pipe with one end inserted into the old bridge flange plate, a vertical sliding plate vertically attached to the end face of the new bridge flange plate for reducing friction, and a steel plate vertically attached to the end face of the old bridge flange plate, wherein the vertical sliding plate and the steel plate are in contact with each other.

[0011] The vertical sliding plate and the steel plate have gaps that allow the horizontal connecting steel bars to pass through.

[0012] Preferably, several transverse connecting steel bars are arranged at intervals along the longitudinal direction of the solid circular steel pipe.

[0013] Furthermore, the transverse connecting steel bar is a single steel bar, which is crisscrossed and wrapped around the outer surface of the solid round steel pipe. Both ends of the transverse connecting steel bar are horizontally inserted into the flange of the old bridge.

[0014] Furthermore, the spacing between adjacent transverse connecting bars is 0.5m to 1m.

[0015] Preferably, the circular channel steel is cast at the end of the new bridge flange plate, with the outer edge of the circular channel steel 5cm to 15cm away from the transverse edge of the new bridge flange plate.

[0016] Furthermore, the curved sliding plate is made of polytetrafluoroethylene or polyoxymethylene.

[0017] Furthermore, the vertical sliding plate is made of polytetrafluoroethylene or polyoxymethylene.

[0018] Preferably, the cross-sectional shape of both the circular channel steel and the arc-shaped sliding plate is an open annular shape.

[0019] The present invention discloses a construction method for a longitudinally sliding continuous beam bridge transverse widening connection structure, comprising the following steps: according to a pre-designed location, inserting transverse connecting steel bars at certain intervals along the longitudinal direction of the bridge into the flange plate of the old bridge;

[0020] The transverse connecting steel bars are crisscrossed and clamped around the outer surface of the solid round steel pipe;

[0021] The outer side of the arc-shaped sliding plate is tightly bonded to the inner wall of the circular channel steel;

[0022] The solid round steel pipe is inserted longitudinally from the end into the round channel steel.

[0023] Steel plates are arranged longitudinally and closely attached to the end of the old bridge flange plate, and vertical sliding plates are arranged longitudinally and closely attached to the end of the new bridge flange plate. After construction, they serve as an isolation layer between the old and new bridge flange plates.

[0024] Finally, after the bottom formwork for the new bridge flange is installed, the new bridge flange can be poured in one go. After curing, it can be demolded, thus achieving the lateral connection between the old and new box girders.

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

[0026] (1) In this invention, the solid round steel pipe can slide longitudinally inside the round channel steel. The arc-shaped sliding plate between the solid round steel pipe and the round channel steel reduces the friction on the interface between the transverse connecting steel bars and the inner contour of the solid round steel pipe, which can provide better longitudinal bridge sliding deformation for the transverse connecting steel bars. This greatly dissipates the longitudinal deformation difference caused by the long-term shrinkage and creep difference between the new and old concrete bridges, and fundamentally solves the problem of excessive transverse bending deformation caused by the longitudinal deformation difference between the new and old bridges when the long concrete bridge is widened, which leads to cracking and damage of the widened structure.

[0027] (2) When transverse and vertical displacements occur between the new and old bridges, the solid circular steel pipe will be squeezed by the outer circular channel steel to constrain it. The intersecting transverse connecting steel bars will also restrict the vertical displacement between the new and old bridges, thereby providing good transverse pull-out capacity and vertical shear resistance for the transverse connecting structure, and improving the safety performance of the widened flange of the new and old bridges under vehicle load and the difference in settlement of the foundation of the new and old bridges.

[0028] (3) In this invention, no cast-in-place concrete is used between the ends of the flange plates of the new and old bridges. Instead, vertical sliding plates and steel plates with low friction are used, which can maximize the longitudinal deformation freedom of the new bridge and eliminate the problem of cracking of cast-in-place concrete.

[0029] (4) In this invention, the transverse connecting steel bars are all integral, and there is no problem with the strength of welding. Furthermore, the transverse steel bars are horizontally inserted into the flange of the old bridge after crossing vertically. The intersecting transverse connecting steel bars can limit the vertical displacement between the new and old bridges, providing good transverse pull-out resistance and vertical shear resistance for the transverse connecting structure. Attached Figure Description

[0030] Figure 1 This is a diagram showing the specific location of the transverse widening connection structure of the longitudinally sliding continuous beam bridge applied in the actual long-span concrete widening structure of the present invention.

[0031] Figure 2 This is a partially enlarged schematic diagram of the transverse widening connection structure of the longitudinally sliding continuous beam bridge in this invention;

[0032] Figure 3 This is a schematic diagram showing the arrangement of the vertical sliding plate and the steel plate in this invention;

[0033] Figure 4 This is a schematic diagram of the transverse connecting steel bars wrapped around a solid circular steel pipe in this invention. Detailed Implementation

[0034] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0035] The longitudinally sliding continuous beam bridge transverse widening connection structure of this invention includes a solid circular steel pipe 1, transverse connecting steel bars 2, circular channel steel 3, arc-shaped sliding plate 4, vertical sliding plate 5, steel plate 6, old bridge flange plate 7, and new bridge flange plate 8. The new bridge flange plate 8 has a groove inside, the opening of which faces the old bridge flange plate 7. The circular channel steel 3 is located in the groove. The cross-section of the circular channel steel 3 is an open ring. The opening of the circular channel steel 3 faces the old bridge flange plate. The circular channel steel 3 is cast near the end of the plate of the new bridge flange plate 8. The outer edge of the circular channel steel 3 is 10cm to 15cm away from the transverse edge of the new bridge flange plate 8. The arc-shaped sliding plate 4 is located on the inner side of the circular channel steel 3. The outer wall of the arc-shaped sliding plate 4 is in close contact with the inner side of the circular channel steel 3. The surface of the arc-shaped sliding plate 4 is smooth and easy to slide. The arc-shaped sliding plate 4 can be made of polytetrafluoroethylene (PTFE) plate or polyoxymethylene (POM) plate. The cross-sectional shape of both the circular channel steel 3 and the arc-shaped sliding plate 4 is an open ring. The solid circular steel pipe 1 is located inside the arc-shaped sliding plate 4. The transverse connecting steel bars 2 are wound around the outer surface of the solid circular steel pipe 1. One end of the transverse connecting steel bars 2 is inserted into the old bridge flange plate. Several transverse connecting steel bars 2 are arranged longitudinally along the solid circular steel pipe 1 at intervals. The spacing between adjacent transverse connecting steel bars 2 is 0.5m to 1m. The transverse connecting steel bars 2 are a whole steel bar. The transverse connecting steel bars 2 are wrapped in a cross shape on the outer surface of the solid circular steel pipe 1. The two ends of the transverse connecting steel bars 2 are inserted into the old bridge flange plate 7 in a horizontal shape. A vertical sliding plate 5 is vertically attached to the end face of the new bridge flange plate. The vertical sliding plate 5 is used to reduce friction and is made of polytetrafluoroethylene or polyoxymethylene. A steel plate 6 is vertically attached to the end face of the old bridge flange plate. The vertical sliding plate 5 and the steel plate 6 are in contact with each other, and gaps are provided on the vertical sliding plate 5 and the steel plate 6 to allow the transverse connecting steel bars 2 to pass through. In this invention, the solid round steel pipe 1 is placed inside the round channel steel 3, and the arc-shaped sliding plate 4 is placed in the gap between the solid round steel pipe 1 and the round channel steel 3. The vertical sliding plate 5 and the steel plate 6 at the joint are located between the old bridge flange plate 7 and the new bridge flange plate 8. One end of the transverse connecting steel bar 2 is inserted into the old bridge flange plate 7, and the other end is crossed and sleeved on the outer surface of the solid round steel pipe 1. The circular channel steel 3 is cast near the end of the new bridge flange plate 8. The outer edge of the circular channel steel is 5-15cm away from the transverse edge of the new bridge flange plate, which can be 10cm. The solid circular steel pipe 1 is placed inside the circular channel steel 3, and the cross-sectional radius of the solid circular steel pipe 1 is slightly smaller than that of the circular channel steel 3, so as to be able to accommodate the arc-shaped sliding plate 4. The two transverse connecting steel bars 2 implanted at each cross section in the old bridge flange plate 7 should be a continuous steel bar without interruption. The transverse connecting steel bars 2 are wrapped around the solid circular steel pipe, then cross each other, and then horizontally implanted into the old bridge flange plate 7.The arc-shaped sliding plate 4 has a semi-circular cross-section, consistent with the arc length of the outer circular channel steel. The outer wall of the arc-shaped sliding plate 4 is tightly bonded to the inner wall of the circular channel steel 3; it is also tightly bonded to the outer surface of the inner solid circular steel pipe 1, serving to isolate the inner solid circular steel pipe from the outer circular channel steel. The inner diameter of the circular channel steel 3 is larger than the outer diameter of the solid circular steel pipe 1, so the thickness of the arc-shaped sliding plate 4 is sufficient. The arc-shaped sliding plate 4 placed in the gap between the solid circular steel pipe 1 and the circular channel steel 3, and the vertical sliding plate 5 located at the joint, can be replaced with plates of other materials, as long as they can meet the requirements of smooth surface and easy sliding, such as polytetrafluoroethylene (PTFE) plates. In the gap between the new and old bridge flanges, excluding the area with transverse connecting reinforcement, the vertical sliding plate 5 is bonded along the longitudinal direction of the new bridge side, while the corresponding position on the old bridge side is bonded with a longitudinally extending steel plate 6. This invention addresses the problem of cracking and damage to long-span concrete continuous beam bridges caused by excessive lateral bending deformation due to the difference in longitudinal deformation between the old and new bridges after widening using traditional hinged wet joint structures. It proposes a longitudinally sliding lateral widening connection structure and construction method for continuous beam bridges, which can largely solve the aforementioned problem, allowing free longitudinal deformation between the old and new bridges without interference in the longitudinal direction. This invention has excellent dissipation capacity for the difference in longitudinal deformation between the old and new bridges during the widening of long-span concrete continuous beam bridges, and provides good resistance to lateral and vertical forces at the lateral connection, which can, to some extent, offset the adverse effects of vehicle loads and the difference in foundation settlement between the old and new bridges on the flange connection.

[0036] The present invention discloses a construction method for a longitudinally sliding continuous beam bridge transverse widening connection structure, comprising the following steps:

[0037] Weld the transverse connecting steel bars to the outer surface of the solid round steel pipe around the perimeter; after welding, cross the other end of the transverse connecting steel bars, and then fold them into a horizontal shape and insert them into the old bridge flange plate; according to the pre-designed position, insert the transverse connecting steel bars into the old bridge flange plate at certain intervals along the longitudinal direction of the bridge, and wrap the transverse connecting steel bars in a cross shape around the outer surface of the solid round steel pipe.

[0038] The outer side of the arc-shaped sliding plate is tightly bonded to the inner wall of the circular channel steel;

[0039] The solid round steel pipe is inserted longitudinally from the end into the round channel steel.

[0040] Steel plates are arranged longitudinally and closely attached to the end of the old bridge flange plate, and vertical sliding plates are arranged longitudinally and closely attached to the end of the new bridge flange plate. After construction, they serve as an isolation layer between the old and new bridge flange plates.

[0041] Finally, after the bottom formwork for the new bridge flange is installed, the new bridge flange can be poured in one go. After curing, it can be demolded, thus achieving the lateral connection between the old and new box girders.

Claims

1. A longitudinally slidable continuous girder bridge transverse widening connection structure, characterized by, The utility model relates to a new and old bridge wing plate transverse connection structure, which comprises a groove opened in a new bridge wing plate (8) and opening towards an old bridge wing plate (7), a circular channel steel (3) located in the groove and opening towards the old bridge wing plate, an arc-shaped sliding plate (4) located on the inner side of the circular channel steel and used for reducing friction, a solid round steel pipe (1) located in the inner side of the arc-shaped sliding plate, a transverse connecting steel bar (2) wound around the outer surface of the solid round steel pipe and embedded into the old bridge wing plate at one end, a vertical sliding plate (5) vertically attached to the end surface of the new bridge wing plate and used for reducing friction, and a steel plate (6) vertically attached to the end surface of the old bridge wing plate, wherein the vertical sliding plate (5) and the steel plate (6) are attached to each other; gaps are formed in the vertical sliding plate (5) and the steel plate (6) to allow the transverse connecting steel bar (2) to pass through, and the transverse connecting steel bar (2) is an integral steel bar, which is cross-shaped and sleeved on the outer surface of the solid round steel pipe (1), and the two ends of the transverse connecting steel bar (2) are embedded into the old bridge wing plate (7) in a horizontal manner.

2. The longitudinally slidable continuous girder bridge transverse widening connection structure according to claim 1, characterized in that: A plurality of transverse connecting steel bars (2) are longitudinally and spacedly arranged along the solid round steel pipe (1).

3. The longitudinally slidable continuous girder bridge transverse widening connection structure according to claim 2, characterized in that: The spacing between adjacent transverse connecting steel bars (2) is 0.5m-1m.

4. The longitudinally slidable continuous girder bridge transverse widening connection structure according to claim 1, characterized in that: The circular channel steel (3) is cast at the plate end position close to the new bridge wing plate (8), and the outer edge of the circular channel steel (3) is 5cm-15cm away from the transverse edge of the new bridge wing plate (8).

5. The longitudinally slidable continuous girder bridge transverse widening connection structure according to claim 1, characterized in that: The material of the arc-shaped sliding plate (4) is polytetrafluoroethylene or polyformaldehyde.

6. The longitudinally slidable continuous girder bridge transverse widening connection structure according to claim 1, characterized in that: The material of the vertical sliding plate (5) is polytetrafluoroethylene or polyformaldehyde.

7. The longitudinally slidable continuous girder bridge transverse widening connection structure according to claim 1, characterized in that: The cross-sectional shape of the circular channel steel (3) and the arc-shaped sliding plate (4) is open ring shape.

8. A method of constructing a transverse widening connection structure of a longitudinally slidable continuous girder bridge according to any one of claims 1 to 7, characterized by, The utility model relates to a new and old bridge wing plate transverse connection structure, which comprises the following steps: According to the designed position, the transverse connecting steel bar is embedded into the old bridge wing plate at a certain distance along the longitudinal direction of the bridge; The transverse connecting steel bar is cross-shaped and sleeved on the outer surface of the solid round steel pipe; The outer side of the arc-shaped sliding plate is tightly attached to the inner wall of the circular channel steel; The solid round steel pipe is longitudinally arranged in the circular channel steel from the end; The steel plate is arranged along the longitudinal direction and tightly attached to the plate end of the old bridge wing plate, the vertical sliding plate is arranged along the longitudinal direction and tightly attached to the plate end of the new bridge wing plate, and the vertical sliding plate serves as a separation layer between the new and old bridge wing plates after construction; Finally, the construction bottom mould of the new bridge wing plate is installed, the new bridge wing plate is poured at one time, demoulded after maintenance, and the transverse connection of the new and old box girders is finally realized.

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