Railway ballastless track steel truss girder end transition structure and construction method

Abstract

The invention discloses a railway ballastless track steel truss girder end transition structure and a construction method. In order to ensure the safety of train operation, the requirement of railway bridge design on the limited value of the beam end corner is met. The device comprises a steel truss girder, wherein bridge deck overhanging longitudinal beams are rigidly connected to the two longitudinal sides of the steel truss girder respectively; a concrete simply supported beam and a bridge abutment are respectively arranged on two longitudinal sides of the steel truss girder; one side of the concrete simply supported beam is rigidly connected with a concrete simply supported beam longitudinal cantilever; the bridge deck overhanging longitudinal beam on one side is supported on the concrete simply supported beam longitudinal cantilever, and the bridge deck overhanging longitudinal beam on the other side is supported on the bridge abutment. By means of the railway ballastless track steel truss girder end transition structure, the problem that when a railway ballastless track steel truss girder is in transition with a conventional simply supported beam and a bridge abutment, a girder end corner is too large and exceeds a standard limit value can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering construction, and in particular relates to a railway ballastless track steel truss beam end transition structure and a construction method. Background Art

[0002] With the advancement of railway construction, the number of railway construction projects in mountainous areas has gradually increased. The proportion of bridge and tunnel structures in mountainous areas is relatively high. In order to reduce the workload of railway operation and maintenance, mountainous areas have given priority to the use of ballastless tracks in recent years.

[0003] In mountainous railways, deep V-shaped or U-shaped valleys between tunnels are typically traversed by a single long-span bridge, or, depending on the valley topography, by combining a long-span bridge with several conventional 32m or 24m simply supported beam spans. Steel truss bridges are often used for connecting tunnels on mountainous railways due to their simple structure, aesthetically pleasing design, well-defined load distribution, ease of construction, and adaptability. Furthermore, ballastless track steel truss bridges have a 50% lower secondary dead load than ballasted track steel truss bridges. From a force perspective, this reduced secondary dead load also reduces the overall steel content of ballastless track steel truss bridges by approximately 15%. Therefore, the use of ballastless track steel truss bridges in mountainous railways will gradually increase.

[0004] To ensure train safety and track structure stability, railway bridge design imposes certain limits on beam end angles, and these requirements are even stricter for ballastless track bridges than for ballasted track bridges. Due to mountainous terrain, the spans of ballastless track steel trusses in mountainous areas are typically larger, and the limit on beam end angles is often a key control factor in ballastless track steel truss design.

[0005] Therefore, when applying steel trusses for ballastless tracks on railways, the problem of controlling the beam end angle in bridge design is faced. There is an urgent need for a transition structure for the beam ends of steel trusses for ballastless tracks. This structure can ensure that the limit requirements for the local beam end angle can be met when the steel trusses for ballastless tracks are connected to abutments or to commonly used 32m or 24m simply supported beams on railways, making the adaptability of steel trusses for ballastless tracks more flexible. Summary of the Invention

[0006] In order to make up for the deficiencies of the prior art, the present invention provides a railway ballastless track steel truss beam end transition structure and construction method to solve the problem of excessively large turning angles at the ends of railway long-span ballastless track steel truss beams.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: The transition structure of the steel truss beam end of the ballastless track railway is as follows: It comprises a steel truss beam, wherein the longitudinal sides of the steel truss beam are rigidly connected to the bridge deck extending longitudinal beams respectively; Concrete simply supported beams and abutments are respectively provided on both longitudinal sides of the steel truss; One side of the concrete simply supported beam is rigidly connected to a longitudinal cantilever of the concrete simply supported beam; The extended longitudinal beam on one side of the bridge deck is supported on the longitudinal cantilever of the concrete simply supported beam, and the extended longitudinal beam on the other side of the bridge deck is supported on the abutment.

[0008] Furthermore, the bridge deck outward longitudinal beam and the steel truss beam are connected by bolting or welding.

[0009] Furthermore, the longitudinal cantilever of the concrete simply supported beam is connected to the concrete simply supported beam by using a method of continuous steel bars and integral concrete pouring.

[0010] Furthermore, the abutment includes an abutment foundation, an abutment back wall is arranged on the abutment foundation, abutment side walls are respectively arranged on both sides of the abutment back wall, and the abutment side walls are respectively connected to the abutment back wall and the abutment foundation.

[0011] Furthermore, the bridge deck outward longitudinal beam is supported on the abutment foundation and is arranged between the two abutment side walls.

[0012] Furthermore, an expansion joint is provided between the concrete simply supported beam and the longitudinal beam extending outward from the bridge deck, and an expansion joint is provided between the longitudinal beam extending outward from the bridge deck and the back wall of the abutment.

[0013] Furthermore, a transition pier is set below the longitudinal cantilever of the concrete simply supported beam and the steel truss beam, the cantilever end of the longitudinal cantilever of the concrete simply supported beam is supported on the transition pier, and the two ends of the steel truss beam are supported on the transition pier and the abutment respectively.

[0014] Furthermore, the outward-extending end supports of the outward-extending longitudinal beams of the bridge deck, the cantilever end supports of the longitudinal cantilevers of the concrete simply-supported beams and the supports of the steel trusses adopt rubber bearings, steel bearings or seismic-isolating bearings.

[0015] The construction method of the transition structure at the end of the steel truss beam of ballastless track railway is as follows: The construction method uses steel trusses and bridge deck extended longitudinal beams for phased construction: When the steel truss beams and the bridge deck's extended longitudinal beams are constructed in stages, the transition piers and abutments are constructed first, and the steel truss beams are pushed or hoisted in sections to be assembled in the designed position. Then the concrete simply supported beams are constructed, and the bridge deck's extended longitudinal beams are hoisted to the designed position. One end of the bridge deck's extended longitudinal beam on the simply supported beam side is supported on the longitudinal cantilever of the concrete simply supported beam, and the other end is temporarily supported on the transition pier. One end of the bridge deck's extended longitudinal beam on the abutment side is supported on the foundation near the abutment's back wall, and the other end is temporarily supported on the abutment foundation. The bridge deck's extended longitudinal beams are consolidated and connected to the steel truss beams, and finally the temporary supports of the bridge deck's extended longitudinal beams are removed to form a complete bridge structure system.

[0016] Beneficial effects of the present invention: 1) The railway ballastless track steel truss girder end transition structure of the present invention can solve the problem of excessive beam end rotation angle exceeding the specification limit when the railway ballastless track steel truss girder transitions with conventional simply supported beams and abutments, thereby improving the adaptability and economy of ballastless track steel truss girder bridges; 2) The construction method of the steel truss girder end transition structure of the ballastless track of the present invention can adjust the reaction force distribution under the action of the deadweight of the structure, reducing or eliminating the negative reaction force at the support of the longitudinal beam extending outward from the bridge deck after the bridge is completed; 3) The structure and construction method of the present invention are simple and clear in force, simple in structure, easy to implement, and have broad application prospects in the field of bridges. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an elevational layout diagram of the connection between the steel truss girder of the ballastless railway track, the concrete simply supported beam and the abutment of the present invention; Figure 2 is the cross-section of the steel truss; Figure 3 It is a partial elevation view of the transition structure between the steel truss beam end and the concrete simply supported beam of the present invention; Figure 4 It is a partial plan view of the transition structure between the steel truss beam end and the concrete simply supported beam of the present invention; Figure 5 It is a partial cross-sectional view of the transition structure between the steel truss beam end and the concrete simply supported beam of the present invention; Figure 6 It is a partial elevational cross-sectional view of the transition structure between the steel truss beam end and the abutment of the present invention; Figure 7 It is a partial plan view of the transition structure between the steel truss beam end and the abutment of the present invention; Figure 8 It is a partial cross-sectional view of the transition structure between the steel truss beam end and the abutment of the present invention; Figure 9 It is a partial elevation view of the transition structure between the steel truss beam end and the abutment of the present invention; In the figure: 1-steel truss, 2-bridge deck extended longitudinal beam, 3-expansion joint, 4-concrete simply supported beam, 5-concrete simply supported beam longitudinal cantilever, 6-transition pier, 7-abutment, 7-1-abutment foundation, 7-2-abutment side wall, 7-3-abutment back wall. DETAILED DESCRIPTION

[0018] The present invention will be described in detail below with reference to specific embodiments.

[0019] The present invention solves the problem of excessively large beam end angles of steel truss beams on long-span ballastless tracks of railways. By extending the longitudinal beams of the bridge deck, the span of the transition between the steel truss beam, the concrete simply supported beam and the abutment is reduced, thereby reducing the beam end angles at the transition between the steel truss beam ends of the ballastless track.

[0020] like Figure 1 、 2 As shown, the railway ballastless track steel truss beam end transition structure of the present invention includes a steel truss beam 1, and the bridge deck extended longitudinal beams 2 are rigidly connected to the steel truss beam 1 on both longitudinal sides; the bridge deck extended longitudinal beams 2 and the steel truss beam 1 are bolted or welded.

[0021] Concrete simply supported beams 4 and abutments 7 are respectively provided on both longitudinal sides of the steel truss beam 1. One side of the concrete simply supported beam 4 is rigidly connected to the concrete simply supported beam longitudinal cantilever 5. The bridge deck extending longitudinal beam 2 on one side is supported on the concrete simply supported beam longitudinal cantilever 5, and the bridge deck extending longitudinal beam 2 on the other side is supported on the abutment 7.

[0022] like Figure 3 、 4 As shown in Figures 5 and 5, the longitudinal cantilever 5 of the concrete simply supported beam is connected to the concrete simply supported beam 4 by using a continuous steel bar and integral concrete casting method; an expansion joint 3 is set between the concrete simply supported beam 4 and the bridge deck's extended longitudinal beam 2, and an expansion joint 3 is set between the bridge deck's extended longitudinal beam 2 and the abutment back wall 7-3.

[0023] like Figure 6 、 7 As shown in Figures 8 and 9, the abutment 7 includes an abutment foundation 7-1, on which an abutment back wall 7-3 is arranged. Abutment side walls 7-2 are arranged on both sides of the abutment back wall 7-3. The abutment side walls 7-2 are connected to the abutment back wall 7-3 and the abutment foundation 7-1 respectively. The bridge deck overhanging longitudinal beam 2 is supported on the abutment foundation 7-1 and is arranged between the two abutment side walls 7-2. The abutment foundation 7-1 can adopt a pile foundation or an expanded foundation according to the load requirements; the cross-section of the abutment side walls 7-2 and the abutment back wall 7-3 can adopt a solid section or a hollow section according to the load requirements.

[0024] A transition pier 6 is set below the longitudinal cantilever 5 of the concrete simply supported beam and the steel truss beam 1. The cantilever end of the longitudinal cantilever 5 of the concrete simply supported beam is supported on the transition pier 6, and the two ends of the steel truss beam 1 are supported on the transition pier 6 and the abutment 7 respectively.

[0025] The outrigger end supports of the outrigger longitudinal beam 2 of the bridge deck, the cantilever end supports of the longitudinal cantilever 5 of the concrete simply supported beam and the supports of the steel truss beam 1 can adopt rubber bearings, steel bearings or seismic isolation bearings according to the force requirements.

[0026] The present invention also provides a construction method for a transition structure at the end of a steel truss beam of a ballastless track railway, specifically comprising: The steel truss girder 1 and the bridge deck extended longitudinal girder 2 are constructed in stages. First, the transition pier 6 and abutment 7 are constructed. The steel truss girder 1 is pushed or hoisted in sections to be assembled at the designed position. Then the concrete simply supported beam 4 is constructed and the bridge deck extended longitudinal girder 2 is hoisted to the designed position. One end of the bridge deck extended longitudinal girder 2 on the simply supported beam side is supported on the concrete simply supported beam longitudinal cantilever 5, and the other end is temporarily supported on the transition pier 6. One end of the bridge deck extended longitudinal girder 2 on the abutment side is supported on the foundation near the back wall of the abutment, and the other end is temporarily supported on the abutment foundation 7-1. The bridge deck extended longitudinal girder 2 is consolidated and connected to the steel truss girder 1. Finally, the temporary support of the bridge deck extended longitudinal girder is removed to form a complete bridge structure system.

[0027] In the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0028] The content of the present invention is not limited to the embodiments listed. Any equivalent transformation of the technical solution of the present invention made by ordinary technicians in this field after reading the description of the present invention is covered by the claims of the present invention.

Claims

1. A transition structure for steel truss beam ends of a ballastless track railway, characterized by: It comprises a steel truss girder (1), wherein both longitudinal sides of the steel truss girder (1) are rigidly connected to a bridge deck extending longitudinal beam (2); Concrete simply supported beams (4) and abutments (7) are respectively provided on both longitudinal sides of the steel truss beam (1); One side of the concrete simply supported beam (4) is rigidly connected to a concrete simply supported beam longitudinal cantilever (5); The outwardly extending longitudinal beam (2) of the bridge deck on one side is supported on the longitudinal cantilever (5) of the concrete simply supported beam, and the outwardly extending longitudinal beam (2) of the bridge deck on the other side is supported on the abutment (7).

2. The railway ballastless track steel truss beam end transition structure according to claim 1, characterized in that: The bridge deck outwardly extending longitudinal beam (2) and the steel truss beam (1) are connected by bolting or welding.

3. The railway ballastless track steel truss beam end transition structure according to claim 2, characterized in that: The longitudinal cantilever (5) of the concrete simply supported beam is connected to the concrete simply supported beam (4) by using a method of continuous steel bars and integral concrete pouring.

4. The railway ballastless track steel truss beam end transition structure according to claim 3, characterized in that: The abutment (7) comprises an abutment foundation (7-1), an abutment back wall (7-3) is provided on the abutment foundation (7-1), abutment side walls (7-2) are respectively provided on both lateral sides of the abutment back wall (7-3), and the abutment side walls (7-2) are respectively connected to the abutment back wall (7-3) and the abutment foundation (7-1).

5. The railway ballastless track steel truss beam end transition structure according to claim 4, characterized in that: The bridge deck outwardly extending longitudinal beam (2) is supported on the abutment foundation (7-1) and is arranged between two abutment side walls (7-2).

6. The railway ballastless track steel truss beam end transition structure according to claim 5, characterized in that: An expansion joint (3) is provided between the concrete simply supported beam (4) and the bridge deck outwardly extending longitudinal beam (2), and an expansion joint is provided between the bridge deck outwardly extending longitudinal beam (2) and the abutment back wall (7-3).

7. The railway ballastless track steel truss beam end transition structure according to claim 6, characterized in that: A transition pier (6) is provided below the longitudinal cantilever (5) of the concrete simply supported beam and the steel truss beam (1); the cantilever end of the longitudinal cantilever (5) of the concrete simply supported beam is supported on the transition pier (6); and the two ends of the steel truss beam (1) are supported on the transition pier (6) and the abutment (7), respectively.

8. The railway ballastless track steel truss beam end transition structure according to claim 7, characterized in that: The outward-extending end supports of the outward-extending longitudinal beams (2) of the bridge deck, the cantilever end supports of the longitudinal cantilevers (5) of the concrete simply-supported beams, and the supports of the steel trusses (1) adopt rubber bearings, steel bearings, or seismic-isolating bearings.

9. A method for constructing a transition structure at the end of a steel truss girder of a ballastless track railway, characterized in that: The construction method adopts the method of constructing steel trusses and bridge deck outward longitudinal beams in stages.

10. The construction method of the railway ballastless track steel truss beam end transition structure according to claim 9, characterized in that: When the steel truss girder (1) and the bridge deck extended longitudinal girder (2) are constructed in stages, the transition pier (6) and the abutment (7) are constructed first, the steel truss girder (1) is pushed or hoisted in sections to the designed position, and then the concrete simply supported girder (4) is constructed, and the bridge deck extended longitudinal girder (2) is hoisted to the designed position; one end of the bridge deck extended longitudinal girder (2) on the simply supported girder side is supported on the concrete simply supported girder longitudinal cantilever (5), and the other end is temporarily supported on the transition pier (6); one end of the bridge deck extended longitudinal girder (2) on the abutment side is supported on the foundation near the abutment back wall, and the other end is temporarily supported on the abutment foundation (7-1); the bridge deck extended longitudinal girder (2) is consolidated and connected to the steel truss girder (1), and finally the temporary support of the bridge deck extended longitudinal girder is removed to form a complete bridge structure system.

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