Cast-in-situ box girder formwork and box girder assembly process

Abstract

The application relates to the technical field of bridge construction, in particular to a cast-in-place box girder formwork and box girder assembly process, a cast-in-place box girder formwork which comprises an outer formwork, an inner formwork, a tensioning assembly and a top corner assembly; the outer formwork is sleeved on the inner formwork, a forming chamber for forming a box girder is arranged between the inner formwork and the outer formwork, the inner formwork is composed of a plurality of first supporting sheets which are connected with each other, a second supporting sheet is connected between two adjacent supporting sheets, the first supporting sheet is used for abutting against an inner side wall of the box girder, the second supporting sheet is used for abutting against an inner side chamfer of the box girder, the tensioning assembly is used for driving the first supporting sheet and the second supporting sheet to move in the direction of approaching or moving away from the outer formwork, the top corner assembly is connected with the second supporting sheet and is used for abutting against the inner side chamfer of the box girder when the second supporting sheet moves away from the box girder. When the application is demoulded, the first supporting sheet and the second supporting sheet are driven by the tensioning assembly to move away from the box girder, so that the deformation amount of the box girder when being demoulded is reduced, and the finished product quality of the box girder is improved.

Description

Technical Field

[0001] This application relates to the technical field of bridge construction, and in particular to a cast-in-place box girder formwork and box girder assembly process. Background Technology Cast-in-place box girders, as a type of bridge load-bearing structure, are currently widely used in the construction of railway and highway bridges. When making box girders, it is necessary to first build inner and outer formwork, then build a metal steel reinforcement frame between the inner and outer formwork, and finally pour concrete slurry onto the steel reinforcement frame using the grouting method. After demolding, they also need to be cured to reach the required strength before they can be used as the main load-bearing structure of the bridge.

[0002] When demolding a box girder, the inner formwork is usually removed first. During the removal of the inner formwork, since the inner formwork is in contact with the box girder, the inner wall of the box girder will undergo slight deformation, which will affect the quality of the finished box girder. Summary of the Invention

[0003] In order to reduce the deformation of the box girder during demolding and improve the finished product quality of the box girder, this application provides a cast-in-place box girder formwork and box girder assembly process.

[0004] Firstly, the technical solution for a cast-in-place box girder formwork provided in this application is as follows: A cast-in-place box girder formwork includes an outer formwork, an inner formwork, a tensioning assembly, and a top corner assembly; The outer template is fitted onto the inner template, and a forming chamber for forming the box girder is provided between the inner template and the outer template. The inner template is composed of multiple first support plates connected to each other, and a second support plate is connected between two adjacent support plates. The first support plates are used to abut against the inner side wall of the box girder, and the second support plates are used to abut against the inner chamfer of the box girder. The tensioning component is used to drive the first support plates and the second support plates to move in the direction of approaching or moving away from the outer template. The apex component is connected to the second support plate and is used to abut against the inner chamfer of the box girder when the second support plate moves away from the box girder.

[0005] By adopting the above technical solution, during the casting of the box girder, the tensioning assembly moves the first and second support plates closer to the outer formwork, thereby supporting the inner formwork to facilitate the subsequent casting and shaping of the box girder. During demolding, the tensioning assembly moves the first and second support plates away from the box girder, reducing friction with the inner wall of the box girder compared to simply removing it. Simultaneously, due to the concentrated force at the chamfer, the corner assembly abuts against the chamfer on the inner wall of the box girder to prevent deformation, thus reducing the amount of deformation during demolding and improving the finished quality of the box girder.

[0006] Optionally, the first support piece includes a first hinge piece, a second hinge piece, and a first hinge rod. The first hinge piece and the second hinge piece are hinged together by the first hinge rod. The tensioning assembly is connected to the first hinge rod and is used to drive the first hinge rod to move in a direction closer to or further away from the outer template.

[0007] By adopting the above technical solution, when the tensioning assembly controls the first hinged rotating rod to move along the direction close to the outer template until the first hinged piece and the second hinged piece are arranged at a 180-degree angle, the inner template is in working condition, and the width of the first support piece is at its maximum. When dismantling the template, the tensioning assembly controls the first hinged rotating rod to move along the direction away from the outer template, the angle between the first hinged piece and the second hinged piece is less than 180 degrees, and the width of the first support piece decreases as it moves away from the box girder, so as to facilitate rapid separation from the box girder.

[0008] Optionally, the ends of the first hinge piece and the second hinge piece that are opposite to each other are both connected to the second support piece, and a second hinge rod is connected between the second support piece and the first hinge piece, and between the second support piece and the second hinge piece.

[0009] By adopting the above technical solution, the second hinge rod can, on the one hand, enable the tensioning component to drive the second support plate to move together with the first support plate, and on the other hand, when the included angle between the first hinge plate and the second hinge plate changes, it avoids the connection with the second support plate, so as to improve the rationality of the structure.

[0010] Optionally, the tensioning assembly includes a tensioning support, a tensioning rod, and a tensioning drive component; The tensioning support is located inside the inner template. One end of the tensioning rod is rotatably hinged to the first hinged rotating rod along its own axis. The tensioning rod is arranged perpendicularly to the first hinged rotating rod, and the other end is slidably installed on the tensioning support along its own axis. The tensioning drive is connected to the tensioning rod and is used to control the tensioning rod to slide in a direction closer to or away from the outer template.

[0011] By adopting the above technical solution, the tensioning support rod is driven to slide along its own axis by the tensioning drive component, thereby driving the first hinged rotating rod to move in the direction of approaching or moving away from the outer template.

[0012] Optionally, the tensioning drive includes a tensioning screw and a tensioning nut. One end of the tensioning screw is coaxially and fixedly connected to the tensioning support rod, and the other end of the tensioning screw is threadedly connected to the tensioning nut. The tensioning nut is connected to a main drive, which is installed on the tensioning support and is used to drive the tensioning nut to rotate along its own axis.

[0013] By adopting the above technical solution, the tensioning nut is rotated by the main drive component, which in turn drives the tensioning screw to move inside the tensioning nut, thereby causing the tensioning support rod to slide smoothly.

[0014] Optionally, the apex assembly includes an apex support rod, an apex screw, and an apex nut; The apex support rod is arranged perpendicular to the second hinged rotating rod. The apex support rod is slidably installed on the tensioning support along its own axis and one end is coaxially connected to the apex screw. The second support plate has an apex through hole for the apex support rod to pass through. The apex screw is threadedly connected to the apex nut. The apex nut is connected to the main drive component. The main drive component is used to drive the apex nut to rotate along its own axis. The rotation direction of the apex nut is opposite to that of the tensioning nut.

[0015] By adopting the above technical solution, the corner nut rotates in the opposite direction to the tension nut, thereby controlling the corner support rod to penetrate the second support plate and abut against the chamfer of the box girder when the first and second support plates are away from the box girder, thus supporting the chamfer of the box girder and reducing the probability of box girder deformation.

[0016] Optionally, the main drive unit includes a dual-head motor, a first main bevel gear, a second main bevel gear, a first auxiliary bevel gear, and a second auxiliary bevel gear; The dual-head motor is mounted on the tensioning support and located between the tensioning rod and the apex rod. The output shaft of the dual-head motor is perpendicular to the tensioning rod and the apex rod. The first and second total bevel gears are coaxially mounted on the output shaft of the dual-head motor. The tensioning nut is coaxially connected to a first auxiliary bevel gear, which meshes with the first total bevel gear. The apex nut is coaxially connected to a second auxiliary bevel gear, which meshes with the second total bevel gear. The first and second auxiliary bevel gears are located between the first and second total bevel gears.

[0017] By adopting the above technical solution, the first and second main bevel gears are driven to rotate by the main drive component, thereby driving the first and second auxiliary bevel gears to rotate in opposite directions, thus achieving the effect that the sliding directions of the apex support rod and the tensioning support rod are opposite.

[0018] Optionally, a roller is provided at the end of the apex support rod that is away from the apex screw.

[0019] By adopting the above technical solution, the impact of the rollers on the shape of the box girder when the corner support rod is pressed against the chamfer of the box girder can be reduced.

[0020] Optionally, a sealing plate is fitted over the top corner through hole of the second support piece. The top of the sealing plate is hinged to the hole wall of the top corner through hole. A sealing groove is provided at the bottom of the hole wall of the top corner through hole, which abuts against the bottom of the sealing plate. The end face of the sealing plate facing the outer template is flush with the second support piece.

[0021] By adopting the above technical solution, the top corner through holes are sealed with sealing plates to avoid affecting the forming of the box girder and to prevent the top corner through holes from becoming blocked.

[0022] Secondly, this application provides a box girder assembly process, which adopts the following technical solution: A box girder assembly process includes the following steps: S1. Fix the base and install the inner template and outer template in sequence; S2. Hoist the steel reinforcement formwork into the molding cavity; S3. The tanker truck pours concrete into the molding cavity from top to bottom. S4. Allow the concrete to set and then cure the box girder. S5. The tensioning assembly drives the first and second support plates away from the box girder, and the top corner assembly abuts against the inner chamfer of the box girder. S6. Lift the inner formwork away from the outer formwork through the gantry, and then remove the outer formwork.

[0023] By adopting the above technical solution, the tensioning component and the top corner component can move the first support plate and the second support plate away from the box girder while shortening the contact time and contact area with the box girder, thereby reducing the deformation of the box girder during demolding and improving the finished product quality of the box girder.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. During demolding, the tensioning assembly moves the first and second support plates away from the box girder, which reduces friction with the inner wall of the box girder compared to simply removing it. Simultaneously, due to the concentrated force at the chamfer, the top corner assembly abuts against the chamfer on the inner wall of the box girder to prevent deformation, thereby reducing the amount of deformation during demolding and improving the finished product quality. 2. When the first and second hinge plates are arranged at a 180-degree angle, the inner formwork is in working condition, and the width of the first support plate is at its maximum. When dismantling the formwork, the angle between the first and second hinge plates is less than 180 degrees to facilitate quick separation from the box girder; 3. The second hinged rotating rod enables the tensioning assembly to move the second support plate together with the first support plate, while avoiding connection obstruction between the first and second support plates, thus ensuring the rationality of the structure. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0026] Figure 2 This is a schematic diagram of the structure of the inner template in the embodiments of this application. Figure 3 This is a first structural schematic diagram of the tensioning assembly, the corner assembly, and the main drive component in the embodiments of this application.

[0027] Figure 4 This is a schematic diagram showing the connection between the sealing plate and the second support plate in an embodiment of this application.

[0028] Figure 5 This is a second structural schematic diagram of the tensioning assembly, the apex assembly, and the main drive component in the embodiments of this application.

[0029] Explanation of reference numerals in the attached figures: 1. Outer template; 2. Inner template; 21. First support piece; 211. First hinge piece; 212. Second hinge piece; 22. Second support piece; 221. Top corner through hole; 222. Sealing slot; 23. First hinge rod; 24. Second hinge rod; 3. Tensioning assembly; 31. Tensioning support; 32. Tensioning rod; 33. Tensioning drive component; 331. Tensioning screw; 332. Tensioning nut; 4. Top corner assembly; 41. Top corner support rod; 42. Top corner screw; 43. Top corner nut; 44. Roller; 5. Main drive component; 51. Dual-head motor; 52. First main bevel gear; 53. Second main bevel gear; 54. First auxiliary bevel gear; 55. Second auxiliary bevel gear; 6. Sealing plate; 7. Molding chamber. Detailed Implementation

[0030] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0031] It should be noted that, in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] This application discloses a cast-in-place box girder formwork.

[0033] Reference Figure 1 and Figure 2 The cast-in-place box girder formwork includes an outer formwork 1, an inner formwork 2, a tensioning assembly 3, and a corner assembly 4. The outer formwork 1 is fitted onto the inner formwork 2, and a forming chamber 7 for forming the box girder is provided between the inner formwork 2 and the outer formwork 1.

[0034] The inner template 2 is composed of multiple interconnected first support pieces 21. A second support piece 22 connects adjacent support pieces. Each first support piece 21 includes a first hinge piece 211, a second hinge piece 212, and a first hinge rod 23. The first hinge piece 211 and the second hinge piece 212 are hinged together by the first hinge rod 23. The opposite ends of the first hinge piece 211 and the second hinge piece 212 are both connected to the second support piece 22. A second hinge rod 24 connects the second support piece 22 to the first hinge piece 211, and also connects the second support piece 22 to the second hinge piece 212.

[0035] In addition, the tensioning component 3 is located inside the inner template 2 and is connected to the first hinged rotating rod 23. The tensioning component 3 is used to drive the first hinged rotating rod 23 to move in the direction of approaching or moving away from the outer template 1, thereby achieving the effect of the first support piece 21 and the second support piece 22 moving in the direction of approaching or moving away from the outer template 1.

[0036] During casting, the first support plate 21 abuts against the inner wall of the box girder, and the second support plate 22 abuts against the inner chamfer of the box girder. During demolding, the tensioning assembly 3 moves the first support plate 21 and the second support plate 22 away from the box girder, which reduces friction with the inner wall of the box girder compared to removing the box girder.

[0037] In addition, since the stress is concentrated at the inner chamfer of the box girder, the top corner assembly 4 is connected to the second support plate 22 and is used to abut against the inner chamfer of the box girder when the second support plate 22 is away from the box girder, so as to prevent the chamfer from deforming, thereby reducing the deformation of the box girder during demolding and improving the finished quality of the box girder.

[0038] Reference Figure 2 and Figure 3 The tensioning assembly 3 includes a tensioning support 31, a tensioning rod 32, and a tensioning drive component 33.

[0039] Among them, the tension support 31 is located at the center inside the inner template 2, one end of the tension support rod 32 is rotatably hinged to the first hinged rotating rod 23 along its own axis, the tension support rod 32 is arranged perpendicularly to the first hinged rotating rod 23 and the other end is slidably installed on the tension support 31 along its own axis.

[0040] In addition, the tensioning drive component 33 includes a tensioning screw 331 and a tensioning nut 332. One end of the tensioning screw 331 is coaxially and fixedly connected to the tensioning support rod 32, and the other end of the tensioning screw 331 is threadedly connected to the tensioning nut 332. The tensioning nut 332 is connected to a main drive component 5, which is installed on the tensioning support 31 and is used to drive the tensioning nut 332 to rotate along its own axis.

[0041] The main drive component 5 drives the tension nut 332 to rotate, which in turn drives the tension screw 331 to move within the tension nut 332, thereby causing the tension support rod 32 to slide smoothly, so as to adjust the position of the first support plate 21 and the second support plate 22.

[0042] Reference Figure 3 and Figure 4 The apex assembly 4 includes an apex support rod 41, an apex screw 42, and an apex nut 43.

[0043] The corner support rod 41 is arranged perpendicular to the second hinged rotating rod 24. The corner support rod 41 is slidably installed on the tension support 31 along its own axis and a roller 44 is installed at one end. The second support plate 22 has a corner through hole 221 through which the corner support rod 41 passes. A sealing plate 6 is covered at the corner through hole 221 of the second support plate 22. The top of the sealing plate 6 is hinged to the hole wall of the corner through hole 221. A sealing groove 222 is formed at the bottom of the hole wall of the corner through hole 221, which abuts against the bottom of the sealing plate 6.

[0044] When the box girder is being poured, the inner formwork 2 is in working condition, the sealing plate 6 is flush with the end face of the outer formwork 1 and the second support plate 22, and the roller 44 is located on the side of the second support plate 22 away from the outer formwork 1, so as not to affect the pouring quality.

[0045] In addition, the end of the apex support rod 41 that is away from the roller 44 is coaxially connected to the apex screw 42. The apex screw 42 is threadedly connected to the apex nut 43. The apex nut 43 is connected to the main drive component 5. The main drive component 5 is used to drive the apex nut 43 to rotate along its own axis, and the apex nut 43 rotates in the opposite direction to the tension nut 332.

[0046] When demolding is required, the main drive component 5 drives the tension nut 332 to rotate forward, the first hinge rotating rod 23 drives the first support plate 21 and the second support plate 22 away from the outer template 1, and at the same time the top corner nut 43 rotates in reverse, the roller 44 on the top corner support rod 41 passes through the top corner through hole 221 and pushes open the sealing plate 6 to abut against the inner chamfer of the box girder, thereby achieving support for the inside of the box girder and reducing the probability of deformation of the box girder.

[0047] Reference Figure 3 and Figure 5 The main drive unit 5 includes a dual-head motor 51, a first main bevel gear 52, a second main bevel gear 53, a first auxiliary bevel gear 54, and a second auxiliary bevel gear 55.

[0048] A dual-head motor 51 is mounted on the tensioning support 31 and located between the tensioning rod 32 and the apex rod 41. The output shaft of the dual-head motor 51 is perpendicular to the tensioning rod 32 and the apex rod 41. A first total bevel gear 52 and a second total bevel gear 53 are coaxially mounted on the output shaft of the dual-head motor 51. A first auxiliary bevel gear 54 is coaxially connected to the tensioning nut 332, and the first auxiliary bevel gear 54 meshes with the first total bevel gear 52. A second auxiliary bevel gear 55 is coaxially connected to the apex nut 43, and the second auxiliary bevel gear 55 meshes with the second total bevel gear 53. The first auxiliary bevel gear 54 and the second auxiliary bevel gear 55 are located between the first total bevel gear 52 and the second total bevel gear 53.

[0049] The main drive component 5 drives the first main bevel gear 52 and the second main bevel gear 53 to rotate, which in turn drives the first secondary bevel gear 54 and the second secondary bevel gear 55 to rotate in opposite directions, thereby achieving the effect that the sliding directions of the apex support rod 41 and the tensioning support rod 32 are opposite. The implementation principle of a cast-in-place box girder formwork according to an embodiment of this application is as follows: When demolding, the main drive component 5 drives the first main bevel gear 52 and the second main bevel gear 53 to rotate together, causing the first set of bevel gears 54 to rotate forward and the second set of bevel gears 55 to rotate in the opposite direction. The tension nut 332 rotates forward, driving the first hinged rotating rod 23 to move away from the outer formwork 1 through the tension screw 331 and the tension support rod 32, so that the first support plate 21 and the second support plate 22 move away from the box girder. The corner nut 43 rotates in the opposite direction, driving the roller 44 to pass through the corner through hole 221 and abut against the inner chamfer of the box girder through the corner screw 42 and the corner support rod 41, thereby reducing the probability of box girder deformation and ultimately reducing the amount of deformation of the box girder during demolding, thus improving the finished quality of the box girder.

[0050] This application also discloses a box girder assembly process. The assembly process includes the following steps: S1. Fix the base, and install the inner template 2 and the outer template 1 in sequence; S2. Hoist the steel reinforcement formwork into the forming chamber 7; S3. The tanker truck pours concrete into the molding chamber 7 from top to bottom; S4. Allow the concrete to set and then cure the box girder. S5. The tensioning assembly 3 drives the first support plate 21 and the second support plate 22 away from the box girder, and the top corner assembly 4 abuts against the inner chamfer of the box girder. S6. Lift the inner template 2 away from the outer template 1 through the gantry, and then remove the outer template 1.

[0051] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A cast-in-place box girder formwork, characterized in that: It includes an outer template (1), an inner template (2), a tensioning assembly (3), and a corner assembly (4); The outer template (1) is fitted onto the inner template (2). A forming chamber (7) for forming a box girder is provided between the inner template (2) and the outer template (1). The inner template (2) is composed of multiple first support pieces (21) connected to each other. A second support piece (22) is connected between two adjacent support pieces. The first support piece (21) is used to abut against the inner side wall of the box girder. The second support piece (22) is used to abut against the inner chamfer of the box girder. The tensioning component (3) is used to drive the first support piece (21) and the second support piece (22) to move in a direction close to or away from the outer template (1). The apex component (4) is connected to the second support piece (22) and is used to abut against the inner chamfer of the box girder when the second support piece (22) is away from the box girder.

2. The cast-in-place box girder formwork according to claim 1, characterized in that: The first support piece (21) includes a first hinge piece (211), a second hinge piece (212), and a first hinge rod (23). The first hinge piece (211) and the second hinge piece (212) are hinged together by the first hinge rod (23). The tensioning assembly (3) is connected to the first hinge rod (23) and is used to drive the first hinge rod (23) to move in a direction closer to or away from the outer template (1).

3. The cast-in-place box girder formwork according to claim 2, characterized in that: The first hinge piece (211) and the second hinge piece (212) are both connected to the second support piece (22) at opposite ends. The second support piece (22) and the first hinge piece (211) are connected to each other, and the second support piece (22) and the second hinge piece (212) are connected to the second hinge rod (24).

4. The cast-in-place box girder formwork according to claim 3, characterized in that: The tensioning assembly (3) includes a tensioning support (31), a tensioning rod (32), and a first driving component; The tensioning support (31) is located inside the inner template (2). One end of the tensioning rod (32) is rotatably hinged to the first hinged rotating rod (23) along its own axis. The tensioning rod (32) is arranged perpendicularly to the first hinged rotating rod (23) and the other end is slidably installed on the tensioning support (31) along its own axis. The first driving member is connected to the tensioning rod (32) and is used to control the tensioning rod (32) to slide in the direction close to or away from the outer template (1).

5. A cast-in-place box girder formwork according to claim 4, characterized in that: The first driving component includes a tensioning screw (331) and a tensioning nut (332). One end of the tensioning screw (331) is coaxially fixedly connected to the tensioning support rod (32), and the other end of the tensioning screw (331) is threadedly connected to the tensioning nut (332). The tensioning nut (332) is connected to a main driving component (5). The main driving component (5) is installed on the tensioning support (31) and is used to drive the tensioning nut (332) to rotate along its own axis.

6. A cast-in-place box girder formwork according to claim 5, characterized in that: The apex assembly (4) includes an apex support rod (41), an apex screw (42), and an apex nut (43); The apex support rod (41) is arranged in a direction perpendicular to the second hinged rotating rod (24). The apex support rod (41) is slidably installed on the tension support (31) along its own axis and one end is coaxially connected to the apex screw rod (42). The second support plate (22) has an apex through hole (221) for the apex support rod (41) to pass through. The apex screw rod (42) is threadedly connected to the apex nut (43). The apex nut (43) is connected to the main drive component (5). The main drive component (5) is used to drive the apex nut (43) to rotate along its own axis. The apex nut (43) rotates in the opposite direction to the tension nut (332).

7. A cast-in-place box girder formwork according to claim 6, characterized in that: The main drive unit (5) includes a dual-head motor (51), a first main bevel gear (52), a second main bevel gear (53), a first auxiliary bevel gear (54), and a second auxiliary bevel gear (55); The dual-head motor (51) is installed on the tension support (31) and located between the tension support rod (32) and the apex support rod (41). The output shaft of the dual-head motor (51) is perpendicular to the tension support rod (32) and the apex support rod (41). The first total bevel gear (52) and the second total bevel gear (53) are coaxially installed on the output shaft of the dual-head motor (51). The tension nut (332) is coaxially connected to the first auxiliary bevel gear (54), which meshes with the first total bevel gear (52). The apex nut (43) is coaxially connected to the second auxiliary bevel gear (55), which meshes with the second total bevel gear (53). The first auxiliary bevel gear (54) and the second auxiliary bevel gear (55) are located between the first total bevel gear (52) and the second total bevel gear (53).

8. A cast-in-place box girder formwork according to claim 6, characterized in that: A roller (44) is provided at the end of the apex support rod (41) that is away from the apex screw rod (42).

9. A cast-in-place box girder formwork according to claim 6, characterized in that: A sealing plate (6) is fitted over the top corner through hole (221) of the second support piece (22). The top of the sealing plate (6) is hinged to the hole wall of the top corner through hole (221). A sealing groove (222) is provided at the bottom of the hole wall of the top corner through hole (221) to abut against the bottom of the sealing plate (6). The end face of the sealing plate (6) facing the outer template (1) is flush with the second support piece (22).

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