A method for constructing end beams

Abstract

The present invention relates to an end cross beam construction method, belonging to the technical field of bridge construction, comprising S1 steel bar construction; S101 straightening the prestressed steel bars of the front beam and the rear beam; S102 respectively laying a first steel mesh and a second steel mesh on the adjacent end faces of the front beam and the rear beam, the first steel mesh and the second steel mesh being connected to the first prestressed steel bar and the second prestressed steel bar respectively; S103 installing a main steel bar system in the middle of the first steel mesh and the second steel mesh, the main steel bar system being located at the upper part of the first prestressed steel bar and the lower part of the second prestressed steel bar, and welding the first prestressed steel bar and the second prestressed steel bar to the main steel bar system; the cross steel bar arrangement and connection performed by the present invention in the bending section are adapted to the complexity and stress characteristics of the bridge structure, so that the stability and durability of the structure can be ensured in the bending section of the bridge.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and in particular relates to a method for constructing an end cross beam. Background Art

[0002] The end beam is located on the platform above the piers and is a transverse member connecting the piers. Its location enables it to effectively share the bridge deck load and transfer it to the piers while ensuring the coordination between the piers.

[0003] The construction method of simply supported first and then continuous mainly follows the following principles: Phased construction: The bridge construction is divided into two stages. The first stage is the installation and erection of prefabricated simply supported components (simple supported stage), and the second stage is the cast-in-place wet joints in the inner support area, wet joint concrete, and the later tensioning of prestressed steel bars to form a complete continuous structure (continuous stage). System conversion: Through the processes of pouring wet joints and tensioning prestressed tendons, the simply supported structure is transformed into a continuous structure.

[0004] During the construction of prefabricated end beams, especially in rivers, lakes and seas, the direction and height of the bridge are affected by geology and ship navigation, so bridges built in rivers, lakes and seas are usually curved and the bridge decks are not at the same level, with undulating lines. However, after the prefabricated beams are hoisted, the height and axial direction between spans will not be completely repeated, which will result in special attention to the connection between spans, that is, the end beams, when constructing the ends of the spans to connect the bridge into a whole.

[0005] For example, a Chinese patent with publication number CN109680604B and titled "A Prefabricated T-Beam Expansion Joint End Structure and Construction Method" discloses the structure of the end beam and its construction method. When the beam is prefabricated, pre-embedded reinforcement is placed at the end of the T-beam on the expansion joint side. After the T-beam is erected in place, the cast-in-place steel bars of the pre-embedded anchor bars of the expansion joint are tied and the pre-embedded anchor bars of the expansion joint are welded to form a whole. The cast-in-place concrete of the pre-embedded anchor bars of the expansion joint is poured. After the concrete design strength reaches more than 80%, the expansion joint assembly is hoisted in place, the pre-embedded anchor bars of the expansion joint and the anchor bars of the expansion joint assembly are welded to form a whole, the reinforcement is tied, and then C50 steel fiber waterproof concrete is poured at the cast-in-place section of the expansion joint assembly. The method solves the problems that the pre-embedded anchor bars at the end of the T-beam are difficult to match with the anchor bars of the expansion joint anchor assembly in terms of lateral position and height, effective welding cannot be formed, and the amount of subsequent renovation work is large.

[0006] Based on the above, during the construction of prestressed concrete beam bridges, the precise matching of the transverse position and height of the embedded anchor bars at the ends of the front beam and the anchor bars at the ends of the rear beam is the key to ensuring structural stability and welding quality. It is difficult to accurately connect the two, which will affect the welding effect and the safety of the overall structure. How to enhance the connection strength between spans and further improve the safety of the bridge is a problem that needs to be solved at present. Summary of the invention

[0007] In order to solve the above problems existing in the prior art, the present invention provides an end crossbeam construction method to solve the problem that it is difficult to accurately connect the steel bars during the construction of wet joints in the curved sections of existing prefabricated bridges, resulting in poor stability of the bridge structure.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] A method for constructing an end cross beam, applicable to the end cross beam, wherein the end cross beam comprises a first prestressed steel bar of a front beam, a second prestressed steel bar of a rear beam, a first steel mesh and a second steel mesh; the axes of the first prestressed steel bar and the second prestressed steel bar intersect in a horizontal plane, and the first steel mesh and the second steel mesh are both arranged at adjacent ends of the front beam and the rear beam; and further comprising the following steps:

[0010] S1, reinforcement construction;

[0011] S101, straightening the prestressed steel bars of the front beam and the rear beam;

[0012] S102, laying the first steel mesh and the second steel mesh on adjacent end surfaces of the front beam and the rear beam, respectively, wherein the first steel mesh and the second steel mesh are connected to the first prestressed steel bars and the second prestressed steel bars, respectively;

[0013] S103, installing a main reinforcement system in the middle of the first reinforcement mesh and the second reinforcement mesh, the main reinforcement system being located above the first prestressed reinforcement and below the second prestressed reinforcement, and welding the first prestressed reinforcement and the second prestressed reinforcement to the main reinforcement system;

[0014] S2, formwork construction; S3, concrete construction; S4, maintenance; S5, wet joint construction.

[0015] Preferably, the construction of the main reinforcement system includes the following steps:

[0016] S1031, erect the quadrilateral frame of the main reinforcement system;

[0017] S1032, installing a steel bar positioning assembly in the quadrilateral frame and adjusting the height and spacing of the steel bar positioning assembly;

[0018] S1033, welding the first prestressed steel bars and the second prestressed steel bars.

[0019] Preferably, the steel bar positioning assembly includes two supporting bars, a hinge block and an adjusting rod; the two supporting bars are cross-hinged at the midpoint, and the hinge block is installed at the hinge point of the two supporting bars; the adjusting rod is rotatably installed on the hinge block, and a connecting rod is also connected to the top of any one of the supporting bars, and both of the connecting rods are hinged to a movable block provided on the adjusting rod, and the adjusting rod is used to adjust the spacing between the supporting bars.

[0020] Preferably, an arc foot support is provided at the end of any of the support ribs, and the arc foot support is used to clamp the support rib to the quadrilateral frame.

[0021] Preferably, S2 includes the following steps:

[0022] S201, construction of transverse partitions, the transverse partitions are made of 15mm thick bamboo plywood;

[0023] S202, construction of bottom formwork, side formwork, web and end formwork.

[0024] Preferably, the template is installed by setting the bottom plate template, the inner and outer side templates of the web, and the end template in a certain order.

[0025] Preferably, in step S3, the wet joint and the wet joints on both sides of the wet joint within the same length range as the negative bending moment beam of the top plate are cast when the daily temperature is lowest.

[0026] Preferably, the S5 further comprises the following steps:

[0027] S501, wet joint connection treatment, the surface concrete of the beam top plate at the connection between the new and old concrete of the wet joint is chiseled off by 5 to 10 mm, and the surface is wetted when pouring concrete;

[0028] S502, wet-joined steel bar construction, the upper layer of the top plate and the lower layer of the bottom plate of the precast beam are connected by single-sided welding; other structural steel bars extending from the precast beam can be tied with wire;

[0029] S503, wet joint formwork construction, wet joint formwork uses 50cm wide bamboo plywood;

[0030] S504, concrete construction.

[0031] Preferably, in step S504, the concrete is poured in two times, the first time for pouring the negative bending moment tensioning section, and the second time for pouring the remaining part.

[0032] The beneficial effects of the present invention are:

[0033] This construction method reduces the requirements for the accuracy of steel bar connection through the combination of prestressed steel bars and steel mesh, thereby simplifying the construction process. The cross steel bar arrangement and connection in the curved section are adapted to the complexity and stress characteristics of the bridge structure, so that the stability and durability of the structure can be ensured in the curved section of the bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0035] Figure 1 A top view of the construction of an end cross beam provided in one embodiment of the present invention;

[0036] Figure 2 A side view of the construction of an end cross beam provided in one embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of a steel bar positioning assembly provided in one embodiment of the present invention;

[0038] Legend: 11. Front beam; 111. First prestressed steel bar; 12. Rear beam; 121. Second prestressed steel bar; 3. First steel mesh; 4. Second steel mesh; 5. Main steel bar system; 6. Steel bar positioning assembly; 61. Support bar; 62. Articulated block; 63. Adjustment rod; 64. Connecting rod; 65. Movable block; 66. Arc foot support. DETAILED DESCRIPTION

[0039] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0040] like Figure 1-Figure 3 As shown, a method for constructing an end cross beam is applicable to the end cross beam, wherein the end cross beam comprises a first prestressed steel bar 111 of a front beam 11, a second prestressed steel bar 121 of a rear beam 12, a first steel mesh 3 and a second steel mesh 4; the axes of the first prestressed steel bar 111 and the second prestressed steel bar 121 intersect in a horizontal plane, and the first steel mesh and the second steel mesh 4 are both arranged at adjacent ends of the front beam 11 and the rear beam 12; and the following steps are also included:

[0041] S1 steel bar construction;

[0042] S101 straightens the prestressed steel bars of the front beam 11 and the rear beam 12;

[0043] S102: The first steel mesh 3 and the second steel mesh 4 are laid on the adjacent end surfaces of the front beam 11 and the rear beam 12, respectively, and the first steel mesh 3 and the second steel mesh 4 are connected to the first prestressed steel bar 111 and the second prestressed steel bar 121 respectively; the first steel mesh 3 and the second steel mesh 4 are laid on the adjacent end surfaces of the front beam 11 and the rear beam 12, respectively, and connected to the prestressed steel bars. This connection method not only enhances the local rigidity of the end cross beam, but also ensures the synergy between the prestressed steel bars and the beam body, thereby improving the integrity of the structure;

[0044] S103 A main reinforcement system 5 is installed in the middle of the first reinforcement mesh 3 and the second reinforcement mesh 4. The main reinforcement system 5 is located at the upper part of the first prestressed reinforcement 111 and the lower part of the second prestressed reinforcement 121, and the first prestressed reinforcement 111 and the second prestressed reinforcement 121 are welded to the main reinforcement system 5. The main reinforcement system 5 is installed in the middle of the reinforcement mesh and welded to the prestressed reinforcement, which further enhances the overall stability and bearing capacity of the structure. The main reinforcement system 5 is located between the prestressed reinforcements, which plays a connecting role, so that the structure can better distribute stress when subjected to external force.

[0045] S2 formwork construction; S3 concrete construction; S4 maintenance; S5, wet joint construction;

[0046] In the curved section of the bridge, due to the complexity of the structural shape and force, the traditional steel bar connection method is often difficult to ensure the precise positioning and effective connection of the steel bars. Due to the up and down staggered connection method of the prestressed steel bars and the steel mesh, even if the steel bars in the curved section cannot be completely aligned and connected, the prestressed force of the prestressed steel bars and the synergistic effect of the steel mesh can ensure the overall stability and bearing capacity of the structure, thereby improving the safety of the bridge.

[0047] Traditional steel bar connection methods are often difficult to construct in curved sections and require precise measurement and positioning. This construction method reduces the requirements for steel bar connection accuracy through the combination of prestressed steel bars and steel mesh. The steel bar arrangement and connection in the curved section are adapted to the complexity and stress characteristics of the bridge structure, ensuring the stability and durability of the structure in the curved section of the bridge.

[0048] In one embodiment, the construction of the main reinforcement system 5 includes the following steps:

[0049] S1031, erecting a quadrilateral frame of the main reinforcement system 5; the quadrilateral frame has good stability and bearing capacity, and can effectively disperse and bear the load from the prestressed reinforcement and other structural members. At the same time, the structure of the quadrilateral frame is simple and clear, and it is convenient for construction personnel to erect and adjust. Erecting the quadrilateral frame is the basis for the construction of the main reinforcement system 5. The quadrilateral frame, as the skeleton of the main reinforcement system 5, provides a stable support platform for subsequent reinforcement positioning, welding and other work. By erecting the frame, the overall stability and positioning accuracy of the main reinforcement system 5 during the construction process can be ensured;

[0050] S1032, install the steel bar positioning assembly 6 in the quadrilateral frame and adjust the height and spacing of the steel bar positioning assembly 6; the steel bar positioning assembly 6 can achieve three-dimensional positioning of the prestressed steel bars by adjusting its height and spacing. The height adjustment ensures the accurate position of the prestressed steel bars in the vertical direction, and the spacing adjustment ensures the reasonable distribution and mutual spacing between the prestressed steel bars, thereby meeting the force requirements of the structure. Adjusting the height and spacing of the steel bar positioning assembly 6 is a key step to ensure the accurate installation of the prestressed steel bars. By accurately adjusting the positioning assembly, the prestressed steel bars can be arranged according to the position and spacing required by the design, thereby ensuring the force performance and durability of the structure. Accurate positioning of the prestressed steel bars helps to reduce stress concentration and the generation of cracks, thereby extending the service life of the structure.

[0051] S1033, welding the first prestressed steel bar 111 and the second prestressed steel bar 121; welding the prestressed steel bars is a key step to firmly connect the prestressed steel bars with the main steel bar system 5. Through welding, it can be ensured that the prestressed steel bars and the main steel bar system 5 form a stable overall structure, jointly bear the external load, and ensure the safety and stability of the bridge; welding uses high temperature to melt the welding rod and the welded metal to form a metallurgical bond, realize the firm connection of two or more metal components, and ensure that the quality and strength of the weld meet the design requirements.

[0052] In one embodiment, the steel bar positioning assembly 6 includes two support bars 61, a hinge block 62 and an adjustment rod 63; the two support bars 61 are cross-hinged at the midpoint, and the hinge block 62 is installed at the hinge point of the two support bars 61; the adjustment rod 63 is rotatably installed on the hinge block 62, and a connecting rod 64 is also connected to the top of any support bar 61, and the two connecting rods 64 are both hinged to the movable block 65 of the adjustment rod 63, and the movable block 65 is threadedly connected to the adjustment rod 63. The adjustment rod 63 rotates to adjust the height of the movable block 65, and the adjustment rod 63 is used to adjust the spacing of the support bars 61; the two support bars 61 are cross-connected by the hinge block 62 at the midpoint, and the hinge design enables the support bars 61 to rotate around the hinge point while maintaining a certain stability. This flexibility is the basis for spacing adjustment; the adjustment rod 63 is rotatably installed on the hinge block 62, and its movable block 65 is hinged to the connecting rod 64 at the top of the support bar 61; it is important that the movable block 65 and the adjustment rod 63 are threadedly connected, which means that when the adjustment rod 63 rotates, due to the interaction of the threads, The movable block 65 will move axially along the adjusting rod 63. When the adjusting rod 63 rotates clockwise or counterclockwise, the movable block 65 will rise or fall according to the guiding effect of the thread. Since the movable block 65 is hinged to the connecting rod 64 of the support rib 61, the height change of the movable block 65 will drive the top of the support rib 61 to move together. Since the support rib 61 is cross-hinged in the middle, the movement of the top will cause the angle between the support ribs 61 to change, thereby realizing the adjustment of the spacing; through the precision of the threaded connection, the precise adjustment of the spacing of the support ribs 61 can be realized, and the problem of difficult position adjustment of the prestressed steel bars with two intersecting axes in the curved section is avoided, thereby avoiding the problem of insufficient structural strength caused by inaccurate steel bar positioning and reducing safety hazards in construction; at the same time, the structure of the steel bar positioning assembly 6 is simple and can adapt to the requirements of working in a narrow space. After the steel bars at the support are tied, the worker takes out the steel bar positioning assembly 6 from the front and moves it to the next support point to ensure that the connection spacing of the prestressed steel bars is consistent at various locations and avoid uneven stress distribution.

[0053] In summary, the rotation of the adjustment rod 63 realizes the spacing adjustment of the support ribs 61 through the threaded connection and the axial movement of the movable block 65. This process is both accurate and efficient, and is of great significance for ensuring construction quality and safety.

[0054] In one embodiment, an arc foot support 66 is provided at the end of each support rib 61. The arc foot support 66 is used to clamp the support rib 61 to the quadrilateral frame, so that the spacing between the support ribs 61 can be adjusted while also adjusting the height and width of the quadrilateral frame, so that it can fit the prestressed steel bars crossing at both ends. Due to the arc shape of the foot support, it can better fit the quadrilateral frame composed of steel bars, reducing shaking and sliding. This stable support ensures that the steel bar positioning assembly 6 can maintain its predetermined position and shape during use, is not easily disturbed by external forces, and also improves the versatility of the steel bar positioning assembly 6.

[0055] In one embodiment, step S2 includes the following steps:

[0056] S201, diaphragm construction, 15mm thick bamboo plywood is used for cast-in-place diaphragms; as an important load-bearing and connecting component, the construction quality of the diaphragm is directly related to the stability and safety of the overall structure. The diaphragm is constructed by cast-in-place method, and 15mm thick bamboo plywood is used as the formwork material. Bamboo plywood has good strength, flatness and processability, making it the preferred material for formwork engineering. During the construction process, the position and size of the diaphragm are first accurately set out according to the design drawings, and then the support system (such as scaffolding or steel support) is set up, followed by laying the bamboo plywood formwork, fixing and leveling to ensure the accuracy and stability of the formwork. After that, hidden works such as steel bar binding and prestressed pipe installation are carried out, and finally concrete is poured and cured to the design strength.

[0057] S202, construction of bottom formwork, side formwork, web formwork and end formwork; the bottom formwork is mainly used to support and fix the concrete bottom, the side formwork and web formwork are used to form the sides and internal space of the structure, and the end formwork is used to close the two ends of the structure. After the formwork is erected, concealed works such as steel bar binding and prestressed pipe installation are also required.

[0058] In one embodiment, the formwork is installed by setting the bottom plate formwork, the inner and outer side formwork of the web, and the end formwork in a sequential order; the bottom plate formwork serves as the basic supporting surface, and its accuracy and flatness directly affect the quality of the entire structure. Installing and accurately adjusting the bottom plate formwork first can ensure the accuracy of subsequent formwork installation and improve the overall quality of the concrete structure. The design of the bottom formwork enclosing the side formwork can enhance the integrity and stability of the formwork system and reduce concrete leakage and appearance defects caused by loose formwork joints; installing in the order of the bottom plate first, the web, and then the end formwork can arrange the formwork support system more reasonably, and the support system of the bottom plate formwork can provide support for the web formwork at the same time, reducing additional support structures and simplifying the construction process; the design of the bottom formwork enclosing the side formwork also facilitates the connection and fixation between the formworks, ensuring that the formwork system will not be displaced or deformed during the concrete pouring process.

[0059] In one embodiment, in step S3, the wet joint and the wet joints on both sides of the wet joints within the same length as the negative bending moment beam of the top plate are cast when the daily temperature is the lowest; the wet joint and the wet joints on both sides of the wet joints within the same length as the negative bending moment beam of the top plate are the key parts of the structural continuity and integrity, and the casting quality of these areas directly affects the bearing capacity, deformation performance and service life of the bridge; the concrete will undergo hydration heat reaction after casting, resulting in an increase in internal temperature. Casting when the daily temperature is the lowest can reduce the internal and external temperature difference, reduce the temperature stress of the concrete caused by excessive temperature difference, and thus reduce the generation of cracks; under low temperature conditions, the hydration reaction rate of the concrete is relatively slow, which is conducive to the full formation and crystallization of the hydration products, thereby improving the strength and durability of the concrete. Low-temperature casting can also reduce the shrinkage deformation of the concrete, because the water inside the concrete evaporates slowly at low temperatures, and the shrinkage and self-shrinkage phenomena are suppressed to a certain extent.

[0060] In one embodiment, step S5 further includes the following steps:

[0061] S501, wet joint connection treatment, chisel off 5 to 10 mm of the surface concrete of the beam top plate at the connection between the new and old concrete of the wet joint, and wet the surface when pouring concrete; First, by chiseling off 5 to 10 mm of the surface concrete of the beam top plate at the connection between the new and old concrete, the purpose is to remove the surface slurry, impurities and loose layers to expose the fresh concrete base with strong bonding strength. Subsequently, wetting the surface before pouring new concrete will help the new concrete to better bond with the old concrete, reduce shrinkage cracks, and improve the strength and durability of the joint;

[0062] S502, wet joint steel bar construction, the upper layer of the top plate and the lower layer of the bottom plate of the precast beam are connected by single-sided welding; other structural steel bars extending from the precast beam can be tied with wire; ensure that the steel bars extending from the precast beam can form an effective mechanical connection with the newly poured wet joint concrete. The main force-bearing reinforcement of the upper layer of the top plate and the lower layer of the bottom plate is connected by single-sided welding to ensure sufficient strength and stiffness transmission; other non-main force-bearing structural steel bars are fixed by wire tying, simplifying the construction process while meeting the connection requirements;

[0063] S503, wet joint formwork construction, wet joint formwork uses 50cm wide bamboo plywood; 50cm wide bamboo plywood is selected as the formwork material because it has good rigidity, stability and reusability, and can effectively control the dimensional accuracy and appearance quality of the wet joint. The installation of the formwork must ensure that the joints are tight and the support is stable to prevent leakage or deformation during concrete pouring;

[0064] S504, concrete construction, after the formwork is installed and accepted, the concrete pouring of the wet joints is carried out. This process requires strict control of concrete mix ratio, slump and other performance indicators to ensure the quality of concrete. During the pouring process, the method of layered pouring and vibration compaction should be adopted to eliminate internal bubbles and voids and improve the density and strength of the concrete.

[0065] In one embodiment, in step S504, concrete is poured twice, the first time for the negative moment tensioning section, and the second time for the remaining part; after the wet joint formwork is installed and accepted, the concrete pouring of the negative moment tensioning section is first carried out. The negative moment area is the part where the bridge bears relatively concentrated tension during operation, so the pouring quality of its concrete is crucial to the stability and durability of the overall structure; during pouring, it should be ensured that the concrete is poured into the formwork evenly and continuously, and an appropriate vibration method, such as an inserted vibrator, is used to ensure that there are no bubbles or voids inside the concrete and the density required by the design is achieved. After the pouring is completed, the concrete surface is smoothed and maintained in time to prevent the moisture from evaporating too quickly and causing cracking. After the concrete of the negative moment tensioning section reaches a certain strength and its internal shrinkage and temperature changes tend to be stable, the remaining part of the concrete is poured; during the second pouring, special attention should be paid to the treatment of the joints between the new and old concrete to ensure that the two can be closely combined to avoid cold joints or stratification. The same uniform pouring method and sufficient vibration are used to ensure the overall quality of the concrete.

[0066] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for constructing an end cross beam, applicable to the end cross beam, the end cross beam comprising a first prestressed steel bar of a front beam, a second prestressed steel bar of a rear beam, a first steel mesh and a second steel mesh; the axes of the first prestressed steel bar and the second prestressed steel bar intersect in a horizontal plane, the first steel mesh and the second steel mesh are both arranged at adjacent ends of the front beam and the rear beam; characterized in that: The following steps are also included: S1, reinforcement construction; S101, straightening the prestressed steel bars of the front beam and the rear beam; S102, laying the first steel mesh and the second steel mesh on adjacent end surfaces of the front beam and the rear beam, respectively, wherein the first steel mesh and the second steel mesh are connected to the first prestressed steel bars and the second prestressed steel bars, respectively; S103, installing a main reinforcement system in the middle of the first reinforcement mesh and the second reinforcement mesh, the main reinforcement system being located above the first prestressed reinforcement and below the second prestressed reinforcement, and welding the first prestressed reinforcement and the second prestressed reinforcement to the main reinforcement system; The construction of the main reinforcement system includes the following steps: S1031, erect the quadrilateral frame of the main reinforcement system; S1032, installing a steel bar positioning assembly in the quadrilateral frame and adjusting the height and spacing of the steel bar positioning assembly; S1033, welding the first prestressed steel bar and the second prestressed steel bar; The steel bar positioning assembly includes two supporting bars, a hinge block and an adjusting rod; the two supporting bars are cross-hinged at the midpoint, and the hinge block is installed at the hinge point of the two supporting bars; the adjusting rod is rotatably installed on the hinge block, and a connecting rod is also connected to the top of any supporting bar, and both connecting rods are hinged to the movable block provided on the adjusting rod, and the adjusting rod is used to adjust the spacing of the supporting bars; The combination of prestressed steel bars and steel mesh reduces the requirements for the accuracy of steel bar connection, thereby simplifying the construction process. The cross steel bar arrangement and connection in the curved section are adapted to the complexity and stress characteristics of the bridge structure, ensuring the stability and durability of the structure in the curved section of the bridge. S2, formwork construction; S3, concrete construction; S4, maintenance; S5, wet joint construction.

2. A method for constructing an end cross beam according to claim 1, characterized in that: The end of any of the supporting ribs is provided with an arc foot support, and the arc foot support is used to clamp the supporting rib to the quadrilateral frame.

3. The end cross beam construction method according to claim 1, characterized in that: S2 includes the following steps: S201, construction of transverse partitions, the transverse partitions are made of 15mm thick bamboo plywood; S202, construction of bottom formwork, side formwork, web and end formwork.

4. A method for constructing an end cross beam according to claim 3, characterized in that: The template installation includes setting the bottom plate template, the inner and outer side templates of the web, and the end template in the order of precedence.

5. The end cross beam construction method according to claim 1, characterized in that: In step S3, the wet joint and the wet joints on both sides of the wet joint within the same length range as the negative bending moment beam of the top plate are cast when the daily temperature is the lowest.

6. The end cross beam construction method according to claim 1, characterized in that: The S5 further comprises the following steps: S501, wet joint connection treatment, the surface concrete of the beam top plate at the connection between the new and old concrete of the wet joint is chiseled off by 5~10mm, and the surface is wetted when pouring concrete; S502, wet-joined steel bar construction, the upper layer of the top plate and the lower layer of the bottom plate of the precast beam are connected by single-sided welding; other structural steel bars extending from the precast beam can be tied with wire; S503, wet joint formwork construction, wet joint formwork uses 50cm wide bamboo plywood; S504, concrete construction.

7. A method for constructing an end cross beam according to claim 6, characterized in that: In step S504, concrete is poured in two steps, the first step is to pour the negative moment tensioning section, and the second step is to pour the remaining part.

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