Pre-camber positioning device and its construction method for reinforced concrete beam bridges

Abstract

This invention provides a pre-camber positioning device and its construction method for reinforced concrete beam bridges, belonging to the field of bridge technology. It includes a slide rail, a first positioning frame, a second positioning frame, an elastic steel plate, and an infrared transmitter. Each first positioning frame has a second positioning frame slidably mounted on both sides along the length of the beam bridge. The heights of both the first and second positioning frames are adjustable and fixed after adjustment. An angle plate is fixedly mounted on both the first and second positioning frames. A clamping plate is rotatably mounted at the center of the angle plate on both the first and second positioning frames. The clamping plate has a groove for engaging the elastic steel plate. Multiple through holes for placing the infrared transmitter are evenly distributed along the length of the elastic steel plate. The infrared transmitter is placed in one of the through holes on one side of the elastic steel plate. This invention facilitates rapid and accurate positioning of the pre-camber of the beam bridge during construction, improving construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of bridge technology, and more specifically, to a pre-camber positioning device for reinforced concrete beam bridges and its construction method. Background Technology

[0002] A beam bridge is a type of bridge that uses a main beam primarily subjected to bending as its load-bearing component. Bridges play an extremely important role in both road and rail transportation, and ensuring their safety is one of its most important issues. In the design, construction, operation, and maintenance of bridges, any slight negligence can lead to huge casualties and economic losses. The pre-camber of a beam bridge, as an important parameter in bridge design, is a correction amount reserved during construction or manufacturing that is opposite to the direction of displacement to counteract the deflection of beams, arches, trusses, and other structures under load.

[0003] Currently, the construction of beam bridge modules mostly involves the following steps: first, building a frame; then laying and reinforcing multiple formwork panels; tying reinforcing bars; pouring concrete; after the concrete dries, transporting it to the bridge construction area by truck; and finally, using a bridge crane to assemble the beam bridge modules onto the bridge piers. When constructing beam bridge modules with pre-camber, construction workers use a variety of equipment, such as rangefinders, levels, and angle gauges, to continuously measure and correct the formwork during the formwork laying process. Because the overall volume of the beam bridge is very large, the measurement and correction of the formwork is quite time-consuming and labor-intensive, resulting in very low overall construction efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a pre-camber positioning device for reinforced concrete beam bridges and its construction method, which facilitates rapid and accurate positioning of the pre-camber of the beam bridge during construction and improves construction efficiency.

[0005] In a first aspect, embodiments of the present invention are achieved through the following technical solution: a pre-camber positioning device for reinforced concrete beam bridges, comprising a slide rail, a first positioning frame, a second positioning frame, an elastic steel plate, and an infrared transmitter; the slide rail is fixedly installed on the ground along the width direction of the beam bridge, and the slide rail is provided with graduations along its own length direction; the first positioning frame is located on both sides of the beam bridge in the width direction and is slidably installed on the slide rail; a second positioning frame is slidably installed on both sides of each first positioning frame in the length direction of the beam bridge; the heights of the first positioning frame and the second positioning frame are both raised and lowered, and the height positions after raising and lowering are fixed; and each of the first positioning frame and the second positioning frame is fixedly equipped with... An angle plate is provided, and clamping plates are rotatably mounted on the first and second positioning frames at the center of the angle plate. The clamping plates have clamping grooves for engaging the elastic steel plate, and a positioning hole is provided at the center of the elastic steel plate. A positioning pin is provided on the clamping plate of the first positioning frame for passing through the positioning hole of the elastic steel plate, and a limiting bolt is provided on the clamping plate of the second positioning frame for abutting and fixing the elastic steel plate. The elastic steel plate has multiple through holes evenly distributed along its length for placing the infrared emitter. The opening direction of the through holes is the same as the width direction of the beam bridge, and the infrared emitter is placed in the through hole of the elastic steel plate on one side.

[0006] Furthermore, both the first positioning frame and the second positioning frame include a base, a bottom rod, a slide rod, and a screw. The base of the first positioning frame is slidably mounted on a slide rail, and the bottom wall of the base of the second positioning frame is fixedly provided with a caster wheel. The bottom rod is fixedly mounted on the base, and the slide rod is slidably inserted into the bottom rod. The slide rod has a scale along its own length direction. The screw is threadedly connected to the bottom rod and is used to abut and fix the slide rod. The angle plate is fixedly mounted on the end of the slide rod.

[0007] Furthermore, guide rods are fixedly provided on the sides of the bases of the two second positioning frames that are close to each other. The two guide rods slide through the base of the first positioning frame at the same time. The guide rods are provided with scales along their own length direction. Positioning bolts for abutting and fixing the guide rods are threaded through the base of the first positioning frame.

[0008] Furthermore, it also includes a diagonal bracing assembly for supporting and positioning the elastic steel plate between the first positioning frame and the second positioning frame. The diagonal bracing assembly includes a rotating plate, a sleeve, a support rod, a clamp, and fixing bolts. The rotating plate is rotatably mounted on the base rod, and the rotation axis of the rotating plate is parallel to the width direction of the beam bridge. The sleeve is fixedly mounted on the rotating plate, and the support rod slides through the sleeve. The clamp is hinged to the support rod, and the clamp has a notch for the elastic steel plate to be moved in. The clamp also has a threaded limit bolt for abutting and fixing the elastic steel plate. The fixing bolts are threaded through the rotating plate and the sleeve, respectively. The base rod has multiple limit holes around the rotation axis of the rotating plate in the circumferential direction for the fixing bolts to be inserted. At the same time, the support rod also has multiple limit holes along its own length direction for the fixing bolts to be inserted.

[0009] Furthermore, the slide rail includes multiple rail rods, which are spliced ​​together in pairs. Slots and inserts are respectively provided between adjacent rail rods. The slots and inserts cooperate with each other. Countersunk bolts for abutting against the inserts are threaded through the rail rods.

[0010] Secondly, embodiments of the present invention are achieved through the following technical solution: a construction method for a pre-camber positioning device for reinforced concrete beam bridges, further comprising:

[0011] S1: First, based on the pre-camber of the beam bridge obtained from the design drawings, place and fix the slide rail in the beam bridge construction area, and slide the first positioning frame along the slide rail to the appropriate position according to the width of the beam bridge. The two first positioning frames are installed opposite each other.

[0012] S2: Then slide the second positioning frames on both sides of the first positioning frame to the appropriate position. During this process, observe the distance between the second positioning frame and the first positioning frame according to the scale on the guide rod until the required position is reached, and fix its position with the positioning bolts.

[0013] S3: Then, insert the elastic steel plate into the clamps of the first positioning frame and the second positioning frame and fix it. During this process, the positioning holes of the elastic steel plate should correspond to the positioning pins for insertion and positioning. Insert an infrared transmitter into the multiple through holes on one side of the elastic steel plate, adjust the height of the first positioning frame and the second positioning frame, and adjust the curvature of the elastic steel plate to be the same as the pre-camber of the beam bridge according to the reading of the elastic steel plate on the angle plate. Then fix the height of the first positioning frame and the second positioning frame.

[0014] S4: Use the clamps of the diagonal bracing assembly to hold and fix the elastic steel plate between the first positioning frame and the second positioning frame, then adjust the length of the support rod in the sliding sleeve, and then adjust the curvature of the elastic steel plate to adapt to the pre-camber of the beam bridge, and fix it with fixing bolts.

[0015] S5: Turn on all infrared transmitters and observe whether the infrared rays emitted by the infrared transmitters are aligned with the through holes of the elastic steel plates on the other side of the beam bridge where no infrared transmitters are installed. Once the infrared rays emitted by the infrared transmitters are aligned with the through holes of the elastic steel plates on the other side of the beam bridge where no infrared transmitters are installed, the installation of the entire positioning device is complete. Finally, the elastic steel plates and the infrared rays emitted by the infrared transmitters are used as positioning references to accurately position the pre-camber of the beam bridge. Subsequently, only the template needs to be laid along the elastic steel plates.

[0016] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0017] 1. This invention involves sliding the second positioning frames on both sides of the first positioning frame to a suitable position. During this process, the distance between the second positioning frame and the first positioning frame is observed according to the scale on the guide rod until the desired distance is reached. The position is then fixed with positioning bolts. Simultaneously, an elastic steel plate is inserted into and fixed to the clamping plates of the first and second positioning frames. During this process, the positioning holes of the elastic steel plate should correspond to the positioning pins for insertion and positioning. An infrared transmitter is inserted into multiple through holes on one side of the elastic steel plate. The height of the first and second positioning frames is adjusted. Based on the reading of the elastic steel plate on the angle plate, the curvature of the elastic steel plate is adjusted to be the same as the pre-camber of the beam bridge. Finally, the first and second positioning frames are fixed. The height of the positioning frame is determined, and then all infrared transmitters are activated. It is observed whether the infrared rays emitted by the infrared transmitters are aligned with the through-holes in the elastic steel plates on the other side of the beam bridge where no infrared transmitters are installed. Once the infrared rays emitted by the infrared transmitters are aligned with the through-holes in the elastic steel plates on the other side of the beam bridge where no infrared transmitters are installed, the pre-camber of the beam bridge is accurately positioned. This can be adjusted according to the length, width, and height of the beam bridge, increasing its adaptability. After the positioning device is installed, only the template needs to be laid along the elastic steel plate before construction, improving construction efficiency. Moreover, the entire positioning device can be used for a long time, and its installation and disassembly are very convenient and cost-effective.

[0018] 2. By setting up diagonal bracing components, the present invention can adjust the curvature of the elastic steel plate to better adapt to the pre-camber of the beam bridge and make the entire elastic steel plate more stable. After adjusting the curvature of the elastic steel plate, the curvature of the elastic steel plate can be made smoother and more precise. The operation is very simple and convenient. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the overall structure of the pre-camber positioning device for reinforced concrete beam bridges provided by the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the pre-camber positioning device for reinforced concrete beam bridges, used as a standalone example of the present invention.

[0022] Figure 3 For the present invention Figure 2 Enlarged view of section A;

[0023] Figure 4 For the present invention Figure 2 Enlarged view of section B;

[0024] Figure 5 This is an exploded view of the diagonal brace assembly, locating pin, and locating hole used in this invention.

[0025] Icons: 1-Slide rail, 10-Scale, 11-Rail rod, 111-Slot, 112-Insertion block, 113-Counterhead bolt, 2-First positioning frame, 21-Base, 211-Wheel caster, 22-Base rod, 221-Slide rod, 222-Screw, 23-Angle plate, 231-Clamping plate, 232-Clamping groove, 233-Positioning pin, 234-Limiting bolt, 3-Second positioning frame, 31-Guide rod, 32-Positioning bolt, 4-Elastic steel plate, 41-Positioning hole, 42-Through hole, 5-Infrared emitter, 6-Diagonal brace assembly, 61-Turn plate, 62-Sleeve, 63-Support rod, 631-Limiting hole, 64-Clamp, 641-Notch, 65-Fixing bolt. Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. Example

[0028] The following description, in conjunction with specific embodiments, provides further details. Figures 1-5As shown, this invention is a pre-camber positioning device for reinforced concrete beam bridges, including a slide rail 1, a first positioning frame 2, a second positioning frame 3, an elastic steel plate 4, and an infrared transmitter 5. The slide rail 1 is fixedly installed on the ground along the width direction of the beam bridge. The slide rail 1 is made of I-beam steel and includes multiple rail rods 11. The multiple rail rods 11 are spliced ​​in pairs. Slots 111 and inserts 112 are respectively provided between adjacent rail rods 11. The cross-section of the inserts 112 is square to prevent the rail rods 11 from rotating relative to each other. The slots 111 and the inserts 112 cooperate with each other. Countersunk bolts 113 are threaded on the rail rods 11 for abutting against the inserts 112. The slide rail 1 is provided with a scale 10 along its length direction. The distance between the two sets of first positioning frames 2 can be adjusted by observing the scale 10 of the slide rail 1.

[0029] The first positioning frame 2 is located on both sides of the beam bridge in the width direction and is slidably mounted on the slide rail 1. A second positioning frame 3 is slidably mounted on both sides of each first positioning frame 2 in the length direction of the beam bridge. The heights of the first positioning frame 2 and the second positioning frame 3 are adjustable and fixed after adjustment. Angle discs 23 are fixedly mounted on both the first positioning frame 2 and the second positioning frame 3. The angle discs 23 are circular and supported by transparent acrylic plates for easy observation and reading. A clamping plate 231 is rotatably mounted on the first positioning frame 2 and the second positioning frame 3 at the center of the angle disc 23. The rotation axis of the clamping plate 231 is parallel to the width direction of the beam bridge. The clamping plate 231 has a clamping groove 232 for engaging the elastic steel plate 4. A positioning hole 41 with a circular cross-section is located at the center of the elastic steel plate 4. A positioning pin 233 is provided on the upper part of the positioning hole 41 for passing through the elastic steel plate 4, so as to position the elastic steel plate 4 and prevent the elastic steel plate 4 from moving. A limiting bolt 234 is provided on the clamping plate 231 of the second positioning frame 3 to abut and fix the elastic steel plate 4, so as to fix the elastic steel plate 4. In this embodiment, since the inside of the beam bridge is bound with steel mesh, the rebound after being subjected to pressure and the overall curvature can be better displayed by the elastic steel plate 4. Therefore, steel plate is selected. The elastic steel plate 4 has multiple through holes 42 evenly opened along its own length direction for placing infrared emitters 5. The opening direction of the through holes 42 is the same as the width direction of the beam bridge. The infrared emitter 5 is installed in the through hole 42 of the elastic steel plate 4 on one side. By opening the infrared emitter 5, infrared rays can be emitted to achieve the purpose of positioning and easy observation.

[0030] Reference Figure 2 , 3Both the first positioning frame 2 and the second positioning frame 3 include a base 21, a bottom rod 22, a slide rod 221, and a screw 222. The base 21 is long and narrow. The base 21 of the first positioning frame 2 is slidably engaged with the slide rail 1, and a positioning bolt 32 is threaded through the base 21 to fix the position of the base 21. The bottom wall of the base 21 of the second positioning frame 3 is fixedly installed with casters 211 to facilitate the movement of the second positioning frame 3. The bottom rod 22 is fixedly welded to the base 21 and is vertically arranged. The slide rod 221 is slidably inserted into the bottom rod 22. The cross-section of the bottom rod 22 and the slide rod 221 are both square. The slide rod 221 is marked with a scale 10 along its length. The screw 222 is threadedly connected to the bottom rod 22 and is used to abut and fix the slide rod 221. A rotating disk is welded to one end of the screw 222 that protrudes from the bottom rod 22 to facilitate rotation by the operator. An angle disk 23 is fixedly installed at the end of the slide rod 221.

[0031] Reference Figure 3 To restrict the movement direction of the second positioning frame 3, guide rods 31 are fixedly welded to the sides of the bases 21 of the two second positioning frames 3 that are close to each other. The guide rods 31 are horizontally set and have a square cross section. The two guide rods 31 slide through the bases 21 of the first positioning frame 2. The guide rods 31 are set with a scale 10 along their own length direction. The bases 21 of the first positioning frame 2 are threaded with positioning bolts 32 for abutting and fixing the guide rods 31, so as to fix the position of the second positioning frames 3 on both sides.

[0032] Reference Figure 3 , 5To make the curvature of the elastic steel plate 4 smoother and better adapt to the pre-camber of the beam bridge, the beam bridge pre-camber positioning device also includes a diagonal bracing assembly 6 for supporting and positioning the elastic steel plate 4 between the first positioning frame 2 and the second positioning frame 3. In this embodiment, two sets of diagonal bracing assemblies 6 are provided and symmetrically installed on the base rod 22 of the first positioning frame 2. In other embodiments, multiple sets of diagonal bracing assemblies 6 can be provided. Both sets of diagonal bracing assemblies 6 include a rotating plate 61, a sleeve 62, a support rod 63, a clamp 64, and a fixing bolt 65. The two rotating plates 61 on each base rod 22 are circular and are rotatably mounted on the base rod 22 on both sides. The rotation axis of the rotating plate 61 is parallel to the width direction of the beam bridge. The sleeve 62 is fixedly welded to the center position of the rotating plate 61. 3 is cylindrical, with support rod 63 slidingly passing through sleeve 62. Clamp 64 is hinged to support rod 63. Clamp 64 has a notch 641 for the elastic steel plate 4 to be moved in. The notch 641 is located on the side facing the beam bridge. Clamp 64 also has a threaded limit bolt 234 for abutting and fixing the elastic steel plate 4 to fix the position of the elastic steel plate 4. Fixing bolts 65 are threaded through rotating plate 61 and sleeve 62 respectively. The bottom rod 22 has multiple limit holes 631 (not shown in the figure) for the fixing bolts 65 to be inserted around the rotation axis of rotating plate 61. At the same time, support rod 63 also has multiple limit holes 631 for the fixing bolts 65 to be inserted along its own length. The position of rotating plate 61 and support rod 63 can be fixed by tightening the corresponding fixing bolts 65.

[0033] In addition, a construction method for a pre-camber positioning device for reinforced concrete bridges also includes:

[0034] S1: First, based on the pre-camber of the beam bridge obtained from the design drawings, place and fix the slide rail 1 in the beam bridge construction area, and slide the first positioning frame 2 along the slide rail 1 to a suitable position according to the width of the beam bridge. The two first positioning frames 2 are installed opposite each other.

[0035] S2: Then slide the second positioning frames 3 on both sides of the first positioning frame 2 to the appropriate position. During this process, observe the distance between the second positioning frame 3 and the first positioning frame 2 according to the scale 10 on the guide rod 31 until the required position is reached, and fix its position with the positioning bolts 32.

[0036] S3: Then, the elastic steel plate 4 is inserted into the clamping plate 231 of the first positioning frame 2 and the second positioning frame 3 and fixed. During this process, the positioning hole 41 of the elastic steel plate 4 should correspond to the positioning pin 233 for insertion and positioning. The infrared transmitter 5 is inserted into the multiple through holes 42 on one side of the elastic steel plate 4. The height of the first positioning frame 2 and the second positioning frame 3 is adjusted. According to the reading of the elastic steel plate 4 on the angle plate 23, the curvature of the elastic steel plate 4 is adjusted to be the same as the pre-camber of the beam bridge. Then, the height of the first positioning frame 2 and the second positioning frame 3 is fixed.

[0037] S4: Use the clamp 64 of the diagonal brace assembly 6 to clamp and fix the elastic steel plate 4 between the first positioning frame 2 and the second positioning frame 3, then adjust the length of the support rod 63 in the sliding sleeve, and then adjust the curvature of the elastic steel plate 4 to adapt to the pre-camber of the beam bridge, and fix it with the fixing bolt 65.

[0038] S5: Turn on all infrared emitters 5 and observe whether the infrared rays emitted by the infrared emitters 5 are aligned with the through holes 42 of the elastic steel plate 4 on the other side of the beam bridge where no infrared emitters 5 are installed. Once the infrared rays emitted by the infrared emitters 5 are aligned with the through holes 42 of the elastic steel plate 4 on the other side of the beam bridge where no infrared emitters 5 are installed, the installation of the entire positioning device is complete. Finally, the elastic steel plate 4 and the infrared rays emitted by the infrared emitters 5 are used as positioning references to achieve accurate positioning of the pre-camber of the beam bridge. Subsequently, only the template needs to be laid along the elastic steel plate 4.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pre-camber positioning device for reinforced concrete beam bridges, characterized in that: It includes a slide rail (1), a first positioning frame (2), a second positioning frame (3), an elastic steel plate (4), and an infrared emitter (5); The slide rail (1) is fixedly installed on the ground along the width direction of the beam bridge. The slide rail (1) has a scale (10) along its own length direction. The first positioning frame (2) is located on both sides of the width direction of the beam bridge and is slidably installed on the slide rail (1). Each first positioning frame (2) is slidably installed on both sides of the length direction of the beam bridge with a second positioning frame (3). The height of the first positioning frame (2) and the second positioning frame (3) is raised and lowered and the height position after raising and lowering is fixed. An angle plate (23) is fixedly installed on the first positioning frame (2) and the second positioning frame (3). A clamping plate (231) is rotatably installed at the center of the angle plate (23) on the first positioning frame (2) and the second positioning frame (3). The upper part is provided with a clamping groove (232) for the elastic steel plate (4) to be clamped. The center position of the elastic steel plate (4) is provided with a positioning hole (41). The clamping plate (231) on the first positioning frame (2) is provided with a positioning pin (233) for passing through the positioning hole (41) of the elastic steel plate (4). The clamping plate (231) on the second positioning frame (3) is provided with a limiting bolt (234) for abutting and fixing the elastic steel plate (4). The elastic steel plate (4) is provided with a plurality of through holes (42) for placing the infrared emitter (5) evenly along its own length direction. The opening direction of the through holes (42) is the same as the width direction of the beam bridge. The infrared emitter (5) is set in the through hole (42) of the elastic steel plate (4) on one side. Both the first positioning frame (2) and the second positioning frame (3) include a base (21), a bottom rod (22), a slide rod (221), and a screw (222). The base (21) of the first positioning frame (2) is slidably mounted on the slide rail (1). The bottom wall of the base (21) of the second positioning frame (3) is fixedly provided with a universal wheel (211). The bottom rod (22) is fixedly mounted on the base (21). The slide rod (221) is slidably inserted into the bottom rod (22). The slide rod (221) is provided with a scale (10) along its own length direction. The screw (222) is threadedly connected to the bottom rod (22) and used to abut and fix the slide rod (221). The angle plate (23) is fixedly mounted on the end of the slide rod (221). Guide rods (31) are fixedly provided on the side of the base (21) of the two second positioning frames (3) that are close to each other. The two guide rods (31) slide through the base (21) of the first positioning frame (2) at the same time. The guide rods (31) are provided with scales (10) along their own length direction. The base (21) of the first positioning frame (2) is threaded with positioning bolts (32) for abutting and fixing the guide rods (31).

2. The pre-camber positioning device for reinforced concrete beam bridges according to claim 1, characterized in that: It also includes a diagonal bracing assembly (6) for supporting and positioning the elastic steel plate (4) between the first positioning frame (2) and the second positioning frame (3). The diagonal bracing assembly (6) includes a rotating plate (61), a sleeve (62), a support rod (63), a clamp (64), and a fixing bolt (65). The rotating plate (61) is rotatably mounted on the bottom rod (22). The rotation axis of the rotating plate (61) is parallel to the width direction of the beam bridge. The sleeve (62) is fixedly mounted on the rotating plate (61). The support rod (63) slides through the sleeve (62). The clamp (64) is hinged to the support rod (63). Next, the clamp (64) is provided with a notch (641) for the elastic steel plate (4) to be moved in. The clamp (64) is also threaded with a limiting bolt (234) for abutting and fixing the elastic steel plate (4). The fixing bolt (65) is threaded on the rotating plate (61) and the sleeve (62) respectively. The bottom rod (22) is provided with multiple limiting holes (631) for the fixing bolt (65) to be inserted around the rotation axis of the rotating plate (61). At the same time, the support rod (63) is also provided with multiple limiting holes (631) for the fixing bolt (65) to be inserted along its own length.

3. The pre-camber positioning device for reinforced concrete beam bridges according to claim 2, characterized in that: The slide rail (1) includes multiple rail rods (11), which are spliced ​​together in pairs. Slots (111) and inserts (112) are respectively provided between adjacent rail rods (11). The slots (111) and inserts (112) cooperate with each other. Countersunk bolts (113) for abutting against the inserts (112) are threaded on the rail rods (11).

4. The construction method of the pre-camber positioning device for reinforced concrete beam bridges according to claim 3, characterized in that: Also includes: S1: First, based on the pre-camber of the beam bridge obtained from the design drawings, place and fix the slide rail (1) in the beam bridge construction area, and slide the first positioning frame (2) along the slide rail (1) to a suitable position according to the width of the beam bridge. The two first positioning frames (2) are installed opposite each other. S2: Then slide the second positioning frames (3) on both sides of the first positioning frame (2) to the appropriate position. During this period, observe the length of the second positioning frame (3) from the first positioning frame (2) according to the scale (10) on the guide rod (31) until the desired position is reached, and fix its position with the positioning bolt (32). S3: Then, the elastic steel plate (4) is inserted into the clamping plate (231) of the first positioning frame (2) and the second positioning frame (3) and fixed. During this period, the positioning hole (41) of the elastic steel plate (4) should correspond to the positioning pin (233) for insertion and positioning. An infrared transmitter (5) is inserted into the multiple through holes (42) on one side of the elastic steel plate (4). The height of the first positioning frame (2) and the second positioning frame (3) is adjusted. According to the reading of the elastic steel plate (4) on the angle plate (23), the curvature of the elastic steel plate (4) is adjusted to be the same as the pre-camber of the beam bridge. Then, the height of the first positioning frame (2) and the second positioning frame (3) is fixed. S4: Use the clamp (64) of the diagonal brace assembly (6) to clamp and fix the elastic steel plate (4) between the first positioning frame (2) and the second positioning frame (3), then adjust the length of the support rod (63) in the sliding sleeve, and then adjust the curvature of the elastic steel plate (4) to adapt to the pre-camber of the beam bridge, and fix it with fixing bolts (65). S5: Turn on all infrared emitters (5) and observe whether the infrared rays emitted by the infrared emitters (5) are aligned with the through holes (42) of the elastic steel plate (4) on the other side of the beam bridge where no infrared emitters (5) are installed. Once the infrared rays emitted by the infrared emitters (5) are aligned with the through holes (42) of the elastic steel plate (4) on the other side of the beam bridge where no infrared emitters (5) are installed, the installation of the entire positioning device is completed. Finally, the elastic steel plate (4) and the infrared rays emitted by the infrared emitters (5) are used as positioning references to achieve accurate positioning of the pre-camber of the beam bridge. Subsequently, it is only necessary to lay the template along the elastic steel plate (4).

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