Cast-in-place box girder formwork supporting frame stretching across existing expressway

Abstract

A cast-in-place box girder formwork supporting frame stretching across an existing expressway comprises a plurality of steel pipe stand columns, the steel pipe stand columns are arranged at intervals in rows along the roadside and the medial strip in the length direction of the existing expressway, longitudinal beams are connected to the tops of the steel pipe stand columns in each row, and cross beams are arranged on the longitudinal beams in a stretching across mode. A plurality of triangular supports used for supporting and crossing a cast-in-place box girder formwork of the existing expressway and a disc buckle type scaffold are erected on the cross beam. Each triangular support is divided into a plurality of sections and is fixedly connected through bolts, and every two adjacent triangular supports are connected through a connecting rod. The cast-in-place box girder formwork supporting frame stretching across the existing expressway is convenient to construct, and the cast-in-place box girder formwork stretching across the existing expressway can be stably supported.

Description

Technical Field

[0001] This invention relates to the technical field of road and bridge construction, specifically to a formwork support frame for cast-in-place box girders spanning existing highways. Background Technology

[0002] Expressways, as a modern high-speed transportation corridor, play a vital role in today's socio-economic development. With the development of multi-level transportation, the construction of new expressways often involves overlapping with existing ones. However, the construction of new interchanges, with their main lines and ramp bridges crossing existing expressways, presents significant safety risks and is a major challenge. Furthermore, the large scale of interchanges, numerous ramps, and overlapping construction activities necessitate a scientific approach to organizing interchange construction while ensuring both safety and progress.

[0003] To effectively avoid traffic conflicts between newly built highways and existing highways, overpasses are needed to bypass them. Traditional overpass construction involves first building the foundations on both sides, then erecting the overpass, and finally constructing its exterior. This process results in long construction periods, high costs, and significant construction difficulties. Furthermore, when constructing bridge segments crossing the existing highway, the corresponding section of the highway must be closed, which increases traffic congestion and economic losses, further raising construction costs. Therefore, cast-in-place box girder designs are typically used to improve the bridge's load-bearing capacity and functionality. Before pouring the concrete, a portal-style support structure is erected to span the existing highway. Then, a modular scaffold is erected on the portal-style support to support the formwork, reducing highway closure time and lowering construction costs.

[0004] To ensure safe passage of the existing expressway, a clearance of 5.5 meters must be maintained. However, application and construction research revealed that during the process, a triangular area with insufficient height often occurs at the intersection of the cast-in-place box girder and the existing expressway projection, making it impossible to erect disc-lock scaffolding to support the formwork. Therefore, a formwork support frame for the cast-in-place box girder spanning the existing expressway needs to be designed. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a cast-in-place box girder formwork support frame that spans an existing highway. This cast-in-place box girder formwork support frame that spans an existing highway is easy to construct and can stably support the cast-in-place box girder formwork that spans an existing highway.

[0006] This invention is achieved using the following technical solution:

[0007] A formwork support frame for cast-in-place box girders spanning an existing highway includes multiple steel pipe columns arranged in rows along the roadside and central median strip of the existing highway. Each row of columns has a longitudinal beam connected to its top, and a transverse beam spans the longitudinal beam. Multiple triangular supports and disc-lock scaffolding are mounted on the transverse beams to support the cast-in-place box girders spanning the existing highway. The disc-lock scaffolding is a readily available and mature formwork support type. Each triangular support is divided into multiple sections and fixed together with bolts. Adjacent triangular supports are connected by connecting rods.

[0008] A further preferred embodiment: Each segment of the triangular bracket is composed of two corresponding vertical angle steels, one inclined angle steel, one diagonal bracing angle steel, and one bottom angle steel welded together. The bottom ends of the two vertical angle steels are vertically welded to the two ends of the bottom angle steel, and the inclined angle steel is welded between the top ends of the two vertical angle steels. The diagonal bracing angle steel is welded to the top end of one vertical angle steel and the bottom end of the other vertical angle steel. Bolt mounting holes are provided on the vertical angle steels at the joint ends of each segment of the triangular bracket.

[0009] A further preferred embodiment: each segment of the triangular bracket has a side connecting angle steel welded parallel to the side of the vertical angle steel at each joint end, and the side connecting angle steel is provided with mounting holes for bolt connection with the connecting rod, and the connecting rod is an angle steel connecting rod.

[0010] A further preferred embodiment: two adjacent steel pipe columns in the same column are connected by connecting rods, so that multiple steel pipe columns in the same column are connected into a whole.

[0011] A further preferred embodiment: the bottom end of the steel pipe column is connected to the concrete foundation, and the concrete foundation contains embedded bolts and embedded connecting steel plates. The embedded connecting steel plates are located on the top surface of the concrete foundation, and the upper ends of the embedded bolts pass through the embedded connecting steel plates. A steel base plate is horizontally welded to the bottom end of the steel pipe column, and the steel base plate is further reinforced to the steel pipe column through base plate reinforcing ribs. The steel base plate and the embedded connecting steel plates are butted together, and the embedded bolts are tightened with nuts after passing through the steel base plate.

[0012] A further preferred embodiment: a steel top plate is horizontally welded to the top of the steel pipe column, and the steel top plate is further reinforced to the steel pipe column through top plate reinforcing ribs.

[0013] A further preferred embodiment: the top surface of the steel top plate is equipped with a sand discharge cylinder, the sand discharge cylinder adopts an existing elevation adjustment device for filling sand inside the cylinder, the upper top surface of the sand discharge cylinder supports and installs a longitudinal beam, and the upper top surface of the sand discharge cylinder is also provided with a limiting angle steel for limiting the longitudinal beam.

[0014] The purpose of this invention is to address the problems existing in the prior art by providing a cast-in-place box girder formwork support frame that spans an existing highway. This cast-in-place box girder formwork support frame that spans an existing highway is easy to construct and can stably support the cast-in-place box girder formwork that spans an existing highway.

[0015] This cast-in-place box girder formwork support system spanning an existing highway involves setting up a portal frame across the highway. Multiple triangular supports and disc-lock scaffolding are erected on the crossbeams of the portal frame to support the cast-in-place box girder formwork spanning the existing highway. The triangular supports are installed in locations where disc-lock scaffolding cannot be erected. Each triangular support is composed of multiple sections and is fixedly connected by bolts. Adjacent triangular supports are connected by connecting rods, making installation convenient and providing stable support. Furthermore, prolonged highway closure is not required during construction. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a cast-in-place box girder spanning an existing highway;

[0017] Figure 2 This is a schematic diagram showing that there is insufficient height at the triangular position where the cast-in-place box girder intersects with the existing high-speed projection.

[0018] Figure 3 This is a schematic diagram of the doorway support arrangement;

[0019] Figure 4 yes Figure 3 A partial schematic diagram of the side structure of the central arch support;

[0020] Figure 5 This is a schematic diagram of the installation structure of the formwork support frame for a cast-in-place box girder spanning an existing highway.

[0021] Figure 6 This is a schematic diagram of the triangular support frame;

[0022] Figure 7 This is a partially enlarged schematic diagram showing the connection relationship between the side connecting angle steel and the vertical angle steel;

[0023] Figure 8 This is a schematic diagram of the connection structure at the base of the steel pipe column;

[0024] Figure 9 This is a schematic diagram of the connection structure at the top of the steel pipe column;

[0025] The names corresponding to the serial numbers in the figure are:

[0026] 1. Concrete foundation; 2. Steel pipe columns; 3. Sand discharge cylinder; 4. Longitudinal beams; 5. Horizontal beams; 6. Triangular supports; 7. Disc-lock scaffolding; 8. Side connecting angle steel; 9. Vertical angle steel; 10. Diagonal angle steel; 11. Diagonal bracing angle steel; 12. Bottom angle steel; 13. Angle steel connecting rod; 14. Embedded bolts; 15. Embedded connecting steel plates; 16. Steel base plate; 17. Base plate reinforcing ribs; 18. Top plate reinforcing ribs; 19. Steel top plate; 20. Limiting angle steel; 21. Connecting tie rods. Detailed Implementation

[0027] The technical solutions of the invention will be clearly and completely described below with reference to the embodiments. The described embodiments are only a part of the present invention, and not all of the embodiments. Example

[0028] A formwork support frame for cast-in-place box girders spanning an existing highway includes multiple steel pipe columns 2, which are arranged in rows along the roadside and central median of the existing highway. Each row of steel pipe columns 2 is connected to a longitudinal beam 4 at its top, and a transverse beam 5 is installed across the longitudinal beam 4. Multiple triangular supports 6 and disc-lock scaffolding 7 for supporting the cast-in-place box girders spanning the existing highway are mounted on the transverse beam 5. The disc-lock scaffolding 7 is an existing and mature disc-lock scaffolding for formwork support. Each triangular support 6 is divided into multiple segments and fixedly connected by bolts. Adjacent triangular supports 6 are connected by connecting rods.

[0029] Each segment of the triangular bracket 6 is composed of two vertical angle steels 9, one inclined angle steel 10, one diagonal bracing angle steel 11, and one bottom angle steel 12 welded together. The bottom ends of the two vertical angle steels 9 are vertically welded to the two ends of the bottom angle steel 12 respectively. The inclined angle steel 10 is welded between the top ends of the two vertical angle steels 9. The diagonal bracing angle steel 11 is welded to the top end of one vertical angle steel 9 and the bottom end of the other vertical angle steel 9 respectively. Bolt mounting holes are provided on the vertical angle steels 9 at the joint ends of each segment of the triangular bracket 6.

[0030] Each segment of the triangular bracket 6 has a vertical angle steel 9 with a side connecting angle steel 8 welded parallel to its side. The side connecting angle steel 8 has mounting holes for bolt connection with the connecting rod. The connecting rod is an angle steel connecting rod 13.

[0031] Two adjacent steel pipe columns 2 in the same column are connected by a connecting rod 21.

[0032] The bottom end of the steel pipe column 2 is connected to the concrete foundation 1. The concrete foundation 1 is pre-embedded with pre-embedded bolts 14 and pre-embedded connecting steel plates 15. The pre-embedded connecting steel plates 15 are located on the top surface of the concrete foundation 1. The upper end of the pre-embedded bolts 14 passes through the pre-embedded connecting steel plates 15. The bottom end of the steel pipe column 2 is horizontally welded with a steel base plate 16. The steel base plate 16 is also reinforced to the steel pipe column 2 through base plate reinforcing ribs 17. The steel base plate 16 and the pre-embedded connecting steel plates 15 are butted together, and the pre-embedded bolts 14 are tightened with nuts after passing through the steel base plate 16.

[0033] The top of the steel pipe column 2 is horizontally welded with a steel top plate 19, and the steel top plate 19 is also reinforcedly connected to the steel pipe column 2 through top plate reinforcing ribs 18.

[0034] The top surface of the steel top plate 19 is fitted with a sand discharge cylinder 3. The sand discharge cylinder 3 adopts an existing elevation adjustment device for filling sand inside the cylinder. The upper top surface of the sand discharge cylinder 3 supports the longitudinal beam 4. The upper top surface of the sand discharge cylinder 3 is also provided with a limiting angle steel 20 for limiting the longitudinal beam 4.

[0035] During construction, steel pipe column foundations are only permitted to be installed on the earthen shoulder and median strip. Two locations involve buried pipelines; a safety survey of the underground pipelines was conducted before construction, and the underground pipelines were relocated. The emergency parking lane and overtaking lane were closed for portal foundation construction, top vegetation and loose soil were removed, and bearing capacity testing was conducted. If the foundation bearing capacity was less than 240 kPa, 50 cm of graded crushed stone was used for replacement and compaction using manual tamping equipment. After the foundation construction was completed, a 1.2 m high and 0.75 m wide C20 concrete cast-in-place strip foundation was constructed on the earthen shoulder. A 1.2 m high and 1.2 m wide C20 concrete cast-in-place strip foundation was also constructed on the median strip. Each foundation segment is 3 m long, with 7.5 cm PVC pipes pre-embedded as lifting holes for easy dismantling and relocation later.

[0036] After the foundation construction is completed, steel pipes are erected on the pre-embedded steel plates in the foundation according to the design elevation and welded in place. Each portal column is supported by two rows of Φ426×10mm steel pipes, connected laterally with channel steel. Steel plates are welded to the top of the steel pipe piles. Then, double-beam crossbeams are hoisted and welded to the top of the steel pipes, with the main crossbeams spaced 300mm apart. Anti-collision sandbags are placed on both sides of the portal support and affixed with reflective tape. 5.5m height restriction devices are installed at both ends of the portal. 5m height restriction traffic safety signs and construction safety signs are hung on the portal height restriction frame. LED warning light strips and reflective tape are hung before and after the portal, and one flashing light is installed on each side to ensure information is available at night, guaranteeing the portal's safety. Traffic control is implemented during the pouring of the portal span to ensure construction safety.

[0037] The above description is not intended to limit the present invention, nor is the present invention limited to the above examples. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should be protected by the present invention.

Claims

1. A formwork support frame for cast-in-place box girder spanning an existing highway, comprising multiple steel pipe columns (2), the multiple steel pipe columns (2) being arranged in rows at intervals along the roadside and central median strip of the existing highway, each row of steel pipe columns (2) having a longitudinal beam (4) connected to its top, and a transverse beam (5) spanning the longitudinal beam (4), characterized in that: The crossbeam (5) is supported by multiple triangular supports (6) and disc-lock scaffolding (7) for supporting the cast-in-place box girder formwork that crosses the existing highway. Each triangular support (6) is divided into multiple sections and is fixedly connected by bolts. Adjacent triangular supports (6) are connected by connecting rods.

2. The formwork support frame for cast-in-place box girders spanning existing highways according to claim 1, characterized in that: Each segment of the triangular bracket (6) is composed of two vertical angle steels (9), one inclined angle steel (10), one diagonal bracing angle steel (11), and one bottom angle steel (12). The bottom ends of the two vertical angle steels (9) are vertically welded to the two ends of the bottom angle steel (12). The inclined angle steel (10) is welded between the top ends of the two vertical angle steels (9). The diagonal bracing angle steel (11) is welded to the top end of one vertical angle steel (9) and the bottom end of the other vertical angle steel (9). Bolt mounting holes are provided on the vertical angle steels (9) at the joint ends of each segment of the triangular bracket (6).

3. The formwork support frame for cast-in-place box girders spanning existing highways according to claim 2, characterized in that: Each section of the vertical angle steel (9) of the triangular bracket (6) is welded with a side connecting angle steel (8) on its side. The side connecting angle steel (8) is provided with mounting holes for bolt connection with the connecting rod. The connecting rod is an angle steel connecting rod (13).

4. The formwork support frame for cast-in-place box girders spanning existing highways according to claim 1, characterized in that: Two adjacent steel pipe columns (2) in the same column are connected by a connecting rod (21).

5. The formwork support frame for cast-in-place box girders spanning existing highways according to claim 1 or 4, characterized in that: The bottom end of the steel pipe column (2) is connected to the concrete foundation (1). The concrete foundation (1) is pre-embedded with pre-embedded bolts (14) and pre-embedded connecting steel plates (15). The pre-embedded connecting steel plates (15) are located on the top surface of the concrete foundation (1). The upper end of the pre-embedded bolts (14) passes through the pre-embedded connecting steel plates (15). The bottom end of the steel pipe column (2) is horizontally welded with a steel base plate (16). The steel base plate (16) is also reinforced to the steel pipe column (2) through the base plate reinforcing ribs (17). The steel base plate (16) and the pre-embedded connecting steel plates (15) are connected, and the pre-embedded bolts (14) are tightened by nuts after passing through the steel base plate (16).

6. The formwork support frame for cast-in-place box girders spanning existing highways according to claim 1 or 4, characterized in that: The top of the steel pipe column (2) is horizontally welded with a steel top plate (19), and the steel top plate (19) is also reinforced to the steel pipe column (2) through a top plate reinforcing rib (18).

7. The formwork support frame for cast-in-place box girders spanning existing highways according to claim 6, characterized in that: The top surface of the steel top plate (19) is limited by a sand discharge cylinder (3), and the upper top surface of the sand discharge cylinder (3) supports the longitudinal beam (4). The upper top surface of the sand discharge cylinder (3) is also provided with a limiting angle steel (20) for limiting the longitudinal beam (4).

Images