Box girder construction method

Abstract

The invention provides a box girder construction method, which relates to the technical field of box girder construction, and comprises the following steps: synchronously prefabricating a plurality of first reinforcing steel bar units, a plurality of second reinforcing steel bar units and a plurality of third reinforcing steel bar units in a factory; penetrating a first connecting steel bar into the intersection of the plurality of first steel bar units; the inner supporting frame is installed into the bottom steel bar assembly; second reinforcing steel bar units are arranged, and second connecting reinforcing steel bars penetrate into the intersections of the bottom reinforcing steel bar assembly and part of the second reinforcing steel bar units; a third steel bar unit is arranged, and the first steel bar unit, the second steel bar unit and the third steel bar unit jointly form a steel bar module; a plurality of steel bar modules are placed in the outer formwork; and concrete is poured in the outer formwork. The precision and the assembling efficiency of the steel bar module are improved, the labor intensity of manual steel bar binding is reduced, meanwhile, the first connecting steel bars and the second connecting steel bars penetrate and are firmly connected, smooth stress transmission between the steel bars is ensured, and the structural integrity and stability of the steel bar module are enhanced.

Description

Technical Field

[0001] This invention relates to the field of box girder construction technology, and more specifically, to a box girder construction method. Background Technology

[0002] Box girders are widely used in railway, highway and municipal bridges. Existing traditional concrete box girders have a wide variety of steel reinforcements, are tightly intersecting and have a complex structure. They are still mainly made up of high-density manual binding operations, which have many problems such as low production efficiency, high labor intensity and poor quality stability. Summary of the Invention

[0003] The purpose of this invention is to provide a method for constructing box girders to improve the aforementioned problems. To achieve this objective, the technical solution adopted by this invention is as follows:

[0004] This application provides a box girder construction method, comprising: simultaneously prefabricating multiple first reinforcing bar units, multiple second reinforcing bar units, and multiple third reinforcing bar units in a factory; placing the multiple first reinforcing bar units on a jig in the factory, inserting first connecting reinforcing bars at the intersection of the multiple first reinforcing bar units, and connecting the first connecting reinforcing bars to the multiple first reinforcing bar units to form a bottom reinforcing bar assembly with an open top; installing an inner support frame into the bottom reinforcing bar assembly; setting second reinforcing bar units connected to the bottom reinforcing bar assembly on both sides and the top of the inner support frame, inserting second connecting reinforcing bars at the intersection of the bottom reinforcing bar assembly and some of the second reinforcing bar units, and connecting the second connecting reinforcing bars to the bottom reinforcing bar assembly and the second reinforcing bar units; setting third reinforcing bar units connected to the second reinforcing bar units on the upper part of the second reinforcing bar units, wherein the first reinforcing bar units, second reinforcing bar units, and third reinforcing bar units together constitute a reinforcing bar module; placing the multiple reinforcing bar modules sequentially along the longitudinal direction of the box girder into the outer formwork at the construction site; and pouring concrete into the outer formwork.

[0005] According to some embodiments of the present invention, the plurality of first reinforcing bar units respectively include a bottom plate reinforcing bar cage and a web reinforcing bar cage. The process of forming a bottom reinforcing bar assembly with an open top includes: placing the bottom plate reinforcing bar cage on a jig; installing two web reinforcing bar cages to both ends of the bottom plate reinforcing bar cage respectively, and inserting the ends of the two web reinforcing bar cages into first receiving spaces at both ends of the bottom plate reinforcing bar cage; inserting first connecting reinforcing bars into the first receiving spaces; and connecting the first connecting reinforcing bars, the bottom plate reinforcing bar cage, and the web reinforcing bar cage.

[0006] According to some embodiments of the present invention, a plurality of second reinforcing steel units respectively include a top plate bottom reinforcing steel mesh and a flange plate bottom reinforcing steel mesh. The arrangement of the plurality of second reinforcing steel units includes: placing the flange plate bottom reinforcing steel mesh on both sides of the inner support frame, with two flange plate bottom reinforcing steel meshes respectively supported on the jig and connected to two web plate reinforcing steel cages; placing the top plate bottom reinforcing steel mesh on the top of the inner support frame, and inserting the free ends of the two web plate reinforcing steel cages into the second receiving spaces at both ends of the top plate bottom reinforcing steel mesh; inserting second connecting steel bars into the second receiving spaces; and connecting the second connecting steel bars, the top plate bottom reinforcing steel mesh, and the web plate reinforcing steel cages.

[0007] According to some embodiments of the present invention, before installing the second reinforcing bar unit, the method further includes: installing two bottom plate top chamfered reinforcing bar meshes into the bottom reinforcing bar assembly; connecting one end of the two bottom plate top chamfered reinforcing bar meshes on the same side to the bottom plate reinforcing bar cage respectively, and connecting the other end of the two bottom plate top chamfered reinforcing bar meshes on the same side to the two web reinforcing bar cages respectively.

[0008] According to some embodiments of the present invention, the method further includes: before setting the top plate bottom steel reinforcement mesh on the top of the inner support frame, installing two top plate bottom chamfered steel reinforcement meshes to both sides of the inner mesh assembly; connecting one end of the two top plate bottom chamfered steel reinforcement meshes on the same side to two web steel reinforcement cages respectively; and after setting the top plate bottom steel reinforcement mesh on the top of the inner support frame, connecting the other end of the two top plate bottom chamfered steel reinforcement meshes on the same side to the top plate bottom steel reinforcement mesh respectively.

[0009] According to some embodiments of the present invention, the third reinforcing bar unit includes a top plate top reinforcing bar mesh, and the provision of the third reinforcing bar unit connected to the second reinforcing bar unit at the top of the inner support frame includes: installing the top plate top reinforcing bar mesh to the top of the inner support frame; and connecting the top plate top reinforcing bar mesh to two web reinforcing bar cages.

[0010] According to some embodiments of the present invention, the third reinforcing bar unit includes a top reinforcing bar mesh of the flange plate. The third reinforcing bar unit, which is provided at the top of the inner support frame and connected to the second reinforcing bar unit, further includes: installing two top reinforcing bar meshes of the flange plate to both sides of the top reinforcing bar mesh of the top plate; and connecting the two top reinforcing bar meshes of the flange plate to the bottom reinforcing bar mesh of the flange plate and the top reinforcing bar mesh of the top plate, respectively.

[0011] According to some embodiments of the present invention, the end faces of a plurality of steel reinforcement modules are arranged parallel to each other, and the plurality of steel reinforcement modules respectively include a first module, a second module and a third module; wherein, the number of the first module, the second module or the third module is set as needed, the two ends of the first module are selectively connected to the second module or the third module respectively, and the end of the second module opposite to the first module is selectively connected to the third module.

[0012] According to some embodiments of the present invention, before pouring concrete inside the outer formwork, the method further includes: inserting pull rods or corrugated pipes inside the first module, the second module, and the third module.

[0013] According to some embodiments of the present invention, the prestressed steel strands are tensioned after the concrete inside the outer formwork has solidified.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention enables precise control of the size, shape, and spacing of the reinforcing steel units by prefabricating the first, second, and third reinforcing steel units in the factory. This reduces assembly errors and improves the precision of the reinforcing steel modules, thereby ensuring that the structural dimensions and stress performance of the box girder meet design requirements. Furthermore, the above-mentioned setup reduces the labor intensity of manually tying the reinforcing steel in the box girder's reinforcing steel skeleton structure. At the same time, by inserting the first and second connecting reinforcing steel and firmly connecting them, it ensures smooth stress transfer between the reinforcing steel, enhancing the structural integrity and stability of the reinforcing steel modules.

[0016] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the box girder construction method of the present invention;

[0019] Figure 2 This is a schematic diagram of the steel reinforcement module of the present invention;

[0020] Figure 3 This is an exploded view of the steel reinforcement module of the present invention;

[0021] Figure 4 This is a schematic diagram of the connection between the first module, the second module, and the third module of the steel reinforcement module of the present invention;

[0022] Figure 5 This is a cross-sectional view of the third module of the present invention;

[0023] Figure 6 This is a cross-sectional view of the second module of the present invention;

[0024] Figure 7 This is a cross-sectional view of the first module of the present invention;

[0025] Figure 8 This is a schematic diagram showing the connection between the frame, the bottom plate reinforcement cage, and the web plate reinforcement cage of the present invention.

[0026] Figure 9 This is a schematic diagram showing the connection of the bottom reinforcing bar assembly, the bottom reinforcing bar mesh of the flange plate, and the bottom reinforcing bar mesh of the top plate according to the present invention;

[0027] Figure 10 This is a schematic diagram showing the connection of the bottom reinforcing bar assembly, the bottom reinforcing bar mesh of the flange plate, the bottom reinforcing bar mesh of the top plate, and the top reinforcing bar mesh of the top plate according to the present invention.

[0028] Marked in the diagram: 1. Tire frame;

[0029] 11. First connecting reinforcement; 12. Second connecting reinforcement; 13. Bottom slab reinforcement cage; 14. Web reinforcement cage; 15. Bottom reinforcement mesh of top slab; 16. Bottom reinforcement mesh of flange plate; 17. Top chamfered reinforcement mesh of bottom slab; 18. Bottom chamfered reinforcement mesh of top slab; 19. Top reinforcement mesh of top slab; 20. Top reinforcement mesh of flange plate;

[0030] 31. Module 1; 32. Module 2; 33. Module 3. Detailed Implementation

[0031] 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, not all, of the embodiments of the present invention. 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. Therefore, the following detailed description of the embodiments of the present 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 present invention without inventive effort are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] like Figure 1 As shown, this embodiment provides a box girder construction method, including:

[0034] Multiple first steel reinforcement units, multiple second steel reinforcement units, and multiple third steel reinforcement units are prefabricated simultaneously in the factory.

[0035] In some embodiments, multiple first steel reinforcement units, multiple second steel reinforcement units, and multiple third steel reinforcement units are prefabricated simultaneously in a factory. By prefabricating multiple first steel reinforcement units, multiple second steel reinforcement units, and multiple third steel reinforcement units simultaneously, the production efficiency of the box girder steel reinforcement skeleton structure can be improved.

[0036] Multiple first steel bar units are placed on a jig 1 in the factory. A first connecting steel bar 11 is inserted at the intersection of the multiple first steel bar units and connected to the multiple first steel bar units to form a bottom steel bar assembly with an open top.

[0037] In some embodiments, a plurality of first reinforcing bar units are placed on a jig 1 in the factory, a first connecting reinforcing bar 11 is inserted at the intersection of the plurality of first reinforcing bar units, and the first connecting reinforcing bar 11 is connected to the intersection of the plurality of first reinforcing bar units to form a stable bottom reinforcing bar assembly with the top of the bottom reinforcing bar assembly open.

[0038] The jig 1 is a tooling fixture in the factory. This jig 1 is used to support and position the first rebar units, so that multiple first rebar units can be stably pre-fixed, and the structural shape and size of the bottom rebar units can be guaranteed, thereby achieving the production consistency of the bottom rebar assembly. The first connecting rebar 11 is used to connect with the intersecting first rebar units, making the connection between the intersecting first rebar units more stable and improving the structural stability of the bottom rebar assembly.

[0039] Install the internal support frame into the bottom steel reinforcement assembly.

[0040] In some embodiments, an inner support frame is installed inside the bottom rebar assembly. The inner support frame can form a pre-fixed and supported second rebar unit, and the inner support frame can stabilize the shape of the bottom rebar assembly inside the bottom rebar assembly. When installing the second and third rebar units, the inner support frame and the jig 1 can jointly fix the shape of the bottom rebar assembly, preventing the second and third rebar units from crushing the bottom rebar assembly during assembly.

[0041] Second steel reinforcement units connected to the bottom steel reinforcement assembly are respectively set on both sides and the top of the inner support frame. Second connecting steel bars 12 are inserted at the intersection of the bottom steel reinforcement assembly and part of the second steel reinforcement units, and the second connecting steel bars 12 are connected to the bottom steel reinforcement assembly and the second steel reinforcement units.

[0042] In some embodiments, second steel reinforcement units connected to the bottom steel reinforcement assembly are respectively provided on both sides of the inner support frame, and the second steel reinforcement units are connected to the bottom steel reinforcement assembly. At the same time, a second steel reinforcement unit is provided on the top of the inner support frame, and a second connecting steel reinforcement 12 is inserted at the intersection of the second steel reinforcement unit and the bottom steel reinforcement assembly on the top of the inner support frame, and the second connecting steel reinforcement 12 is connected to the second steel reinforcement unit and the bottom steel reinforcement assembly on the top of the inner support frame. This can improve the connection stability between the second steel reinforcement unit and the bottom steel reinforcement assembly on the top of the inner support frame.

[0043] Alternatively, a second connecting steel bar 12 can be inserted at the intersection of the second steel bar unit and the bottom steel bar assembly on both sides of the inner support frame, and the second connecting steel bar 12 can be connected to the second steel bar unit and the bottom steel bar assembly on both sides of the inner support frame to further improve the structural stability of the box girder steel bar skeleton structure.

[0044] A third reinforcing bar unit is provided above the second reinforcing bar unit and connected to the second reinforcing bar unit. The first reinforcing bar unit, the second reinforcing bar unit and the third reinforcing bar unit together constitute a reinforcing bar module.

[0045] In some embodiments, multiple third reinforcing bar units are respectively installed above the second reinforcing bar units, and the multiple third reinforcing bar units are connected to each other, and the multiple third reinforcing bar units are respectively connected to adjacent second reinforcing bar units, thereby forming a complete box girder reinforcing bar skeleton structure, which is the aforementioned reinforcing bar module.

[0046] Multiple steel reinforcement modules are placed sequentially along the longitudinal direction of the box girder inside the outer formwork at the construction site.

[0047] In some embodiments, after the steel reinforcement modules are assembled in the factory, they are transported to the construction site using transportation vehicles such as trucks, cranes, and gantry cranes, and placed inside the outer formwork. Multiple steel reinforcement modules are arranged in sequence and fixed together by means of fasteners, welding, or binding.

[0048] It is worth mentioning that after the rebar modules are assembled in the factory, the inner support frame can be removed to allow for the recycling of the inner support frame and to reduce the weight of the rebar modules, thus facilitating their transportation. Multiple rebar modules are placed on the outer formwork on site before the inner formwork is installed.

[0049] Concrete is poured inside the outer formwork.

[0050] In some embodiments, concrete is poured inside the outer formwork, with the concrete located between the outer and inner formwork. The solidified concrete, together with multiple steel reinforcement modules, forms a box girder.

[0051] It should be noted that the installation and setup mentioned in this application can be achieved using intelligent construction methods such as hoisting, in order to improve the production convenience and efficiency of steel reinforcement modules.

[0052] Understandably, prefabricating steel reinforcement units in a factory, utilizing the relatively stable environment and advanced intelligent equipment, allows for more precise control over the size, shape, and quality of the steel reinforcement, improving the accuracy and efficiency of steel reinforcement unit production. This enhances the consistency of steel reinforcement module production, making it easier to combine multiple steel reinforcement modules on the construction site, thus increasing the difficulty of on-site construction of box girders.

[0053] Meanwhile, by inserting the first connecting steel bar 11 and the second connecting steel bar 12 and connecting them to the corresponding steel bar units, the mechanical interlocking force and friction between the steel bars are used to firmly connect the various steel bar units together to form an integral box girder steel bar skeleton structure, so as to effectively transfer the stress between the steel bars and enhance the integrity and deformation resistance of the box girder steel bar skeleton structure.

[0054] It is worth mentioning that each of the first, second, and third steel reinforcement units is a modular structure. Its simple structure allows for assembly line manufacturing in the factory, while robotic arms and other means are used to achieve automated production.

[0055] After the first, second, and third reinforcing bar units are produced, they can be installed using fully or semi-automatic production equipment in the factory, along with the internal support frame. Manual binding and fixing are then performed after the first, second, and / or third reinforcing bar units are in place. Compared to the traditional method of manually stacking and binding reinforcing bars one by one to form the final box girder reinforcing bar skeleton, this application only requires manual binding between the reinforcing bar units, reducing the labor intensity of manual binding, minimizing errors caused by manual binding, and improving the consistency and quality of the reinforcing bar modules.

[0056] According to the box girder construction method of the present invention, the factory prefabrication of the first, second, and third reinforcing steel units can precisely control the size, shape, and spacing of the reinforcing steel units, reduce the error in assembling the reinforcing steel modules, and improve the accuracy of the reinforcing steel modules, thereby ensuring that the structural dimensions and stress performance of the box girder meet the design requirements. In addition, the above-mentioned arrangement also reduces the labor intensity of manual binding of reinforcing steel in the box girder reinforcing steel skeleton structure. At the same time, by inserting the first connecting reinforcing steel 11 and the second connecting reinforcing steel 12 and firmly connecting them, the stress transfer between the reinforcing steel can be ensured smoothly, enhancing the structural integrity and stability of the reinforcing steel modules.

[0057] Please refer to some embodiments of the present invention. Figure 2 , Figure 3 and Figure 8 The process of forming a bottom reinforcement assembly with an open top, comprising multiple first reinforcement units, each including a bottom slab reinforcement cage 13 and a web reinforcement cage 14, includes:

[0058] Place the bottom plate steel reinforcement cage 13 on the frame 1.

[0059] In some embodiments, the bottom plate reinforcement cage 13 and the web reinforcement cage 14 are produced simultaneously in the factory. The prefabricated bottom plate reinforcement cage 13 is placed on the jig 1 in the factory. The jig 1 serves to support and position the bottom plate reinforcement cage 13, ensuring that the bottom plate reinforcement cage 13 is accurately and stably positioned during subsequent assembly.

[0060] Two web reinforcement cages 14 are installed at both ends of the bottom plate reinforcement cage 13, and the ends of the two web reinforcement cages 14 are inserted into the first receiving space at both ends of the bottom plate reinforcement cage 13.

[0061] In some embodiments, two web reinforcement cages 14 are installed at both ends of the bottom plate reinforcement cage 13, and the ends of the two web reinforcement cages 14 are inserted into the first receiving space at both ends of the bottom plate reinforcement cage 13. The first receiving space is a pre-designed structure at both ends of the bottom plate reinforcement cage 13 for accommodating the ends of the web reinforcement cages 14. The first receiving space can make the web reinforcement cages 14 and the bottom plate reinforcement cage 13 tightly connected.

[0062] The first connecting steel bar 11 is inserted into the first containment space.

[0063] In some embodiments, a first connecting steel bar 11 is inserted into the first receiving space. The function of the first connecting steel bar 11 is to strengthen the connection between the web steel cage 14 and the bottom plate steel cage 13. By inserting the first connecting steel bar 11 into the first receiving space, the connection stability between the web steel cage 14 and the bottom plate steel cage 13 can be improved.

[0064] Connect the first connecting steel bar 11, the bottom plate steel cage 13, and the web steel cage 14.

[0065] Specifically, the first connecting steel bar 11, the bottom plate steel cage 13, and the web steel cage 14 are connected together. The connection method can be common steel bar connection methods such as welding and binding, so that the three form a whole and together constitute the bottom steel bar assembly with an open top.

[0066] Understandably, the prefabricated bottom slab reinforcement cage 13 and web reinforcement cage 14 can be manufactured in a factory using specialized molds and equipment, enabling more precise control over the size, shape, and spacing of the reinforcement bars and reducing the impact of human factors and the on-site environment on the precision of reinforcement bar fabrication. Furthermore, through the positioning of the jig 1 and the design of the first receiving space, the relative position of the web reinforcement cage 14 and the bottom slab reinforcement cage 13 can be accurately controlled during assembly, ensuring that the structural dimensions of the assembled bottom reinforcement assembly meet design requirements and improving the overall precision of the box girder structure.

[0067] It is worth mentioning that the first connecting steel bar 11 is inserted into the first receiving space and connected to the bottom plate steel cage 13 and the web steel cage 14, forming multiple connection defense lines, which enhances the strength and rigidity of the connection parts, so as to effectively transfer the stress between the web steel cage 14 and the bottom plate steel cage 13, enabling the web steel cage 14 and the bottom plate steel cage 13 to work together to jointly bear the external load and improve the overall stability of the bottom steel reinforcement assembly.

[0068] Please refer to some embodiments of the present invention. Figure 2 , Figure 3 and Figure 9 Multiple second reinforcement units include a top slab bottom reinforcement mesh 15 and a flange slab bottom reinforcement mesh 16, respectively. When multiple second reinforcement units are provided, they include:

[0069] The bottom steel mesh 16 of the flange plate is set on both sides of the inner support frame. The two bottom steel meshes 16 of the flange plate are respectively supported on the frame 1 and connected to the two web steel cages 14 respectively.

[0070] The bottom steel mesh 15 of the top slab is placed on the top of the inner support frame, and the free ends of the two web steel cages 14 are inserted into the second receiving space at both ends of the bottom steel mesh 15 of the top slab.

[0071] The second connecting steel bar 12 is inserted into the second containment space.

[0072] Connect the second connecting steel bar 12, the bottom steel mesh of the top slab 15, and the web steel cage 14.

[0073] In some embodiments, the flange bottom steel mesh 16 is placed on both sides of the inner support frame, and the two flange bottom steel meshes 16 are respectively supported on the jig 1. Then, the two flange bottom steel meshes 16 are respectively connected to the two web steel cages 14. Next, the top plate bottom steel mesh 15 is placed on the top of the inner support frame. Then, the free ends of the two web steel cages 14 are inserted into the second receiving spaces at both ends of the top plate bottom steel mesh 15 (the second receiving space is a pre-designed structure at both ends of the top plate bottom steel mesh 15 to accommodate the free ends of the web steel cages 14, so as to realize the spatial docking of the top plate bottom steel mesh 15 and the web steel cages 14). Then, the second connecting steel bar 12 is inserted into the second receiving space, and the second connecting steel bar 12, the top plate bottom steel mesh 15 and the web steel cage 14 are connected.

[0074] It is worth mentioning that the jig 1 provides support for the bottom steel mesh 16 of the flange plate, ensuring the stability of the position of the bottom steel mesh 16 of the flange plate; the connection between the bottom steel mesh 16 of the flange plate and the web steel cage 14 forms a preliminary connection between the bottom steel mesh 16 of the flange plate and the web steel cage 14. The second connecting steel bar 12 is used to strengthen the connection between the bottom steel mesh 15 of the top plate and the web steel cage 14. The second connecting steel bar 12 is inserted into the second receiving space to achieve the pre-fixation of the bottom steel mesh 15 of the top plate and the web steel cage 14.

[0075] The second connecting steel bar 12, the top slab bottom steel mesh 15, and the web steel cage 14 are connected. Common connection methods such as welding and binding can be used to make the three form a whole and jointly participate in the stress of the box girder structure.

[0076] Understandably, the precast top slab bottom steel mesh 15 and flange slab bottom steel mesh 16 can be manufactured in the factory using professional molds and equipment, precisely controlling the size, shape and spacing of the steel bars, reducing the influence of human factors and on-site environmental factors, and ensuring the accuracy of steel mesh manufacturing.

[0077] Furthermore, with the help of the internal support frame, the positioning of the jig 1, and the design of the second receiving space, the relative positions of each part can be accurately controlled when setting the second steel reinforcement unit, so that the bottom steel reinforcement mesh 16 of the flange plate, the bottom steel reinforcement mesh 15 of the top plate and the web steel reinforcement cage 14 are precisely connected, improving the overall structural accuracy of the box girder and ensuring that the structural dimensions meet the design requirements. At the same time, the second connecting steel reinforcement 12 passes through the second receiving space and connects with the relevant steel reinforcement unit, enhancing the strength and rigidity of the connection part, effectively transferring stress, and improving the structural quality of the box girder.

[0078] According to some embodiments of the present invention, before installing the second reinforcing bar unit, the method further includes:

[0079] Install two bottom plate top chamfered steel mesh 17 into the bottom steel reinforcement assembly.

[0080] Connect one end of the two bottom plate top chamfered steel meshes 17 on the same side to the bottom plate steel cage 13 respectively, and connect the other end of the two bottom plate top chamfered steel meshes 17 on the same side to the two web steel cages 14 respectively.

[0081] In some embodiments, the holes inside the box girder can reduce the amount of concrete and steel bars used in the manufacture of the box girder without affecting the structural strength of the box girder. A chamfered structure is provided at the junction of the adjacent inner walls of the holes, and the chamfered steel mesh 17 at the top of the bottom plate corresponds to the chamfered structure at the bottom of the holes. Thus, the chamfered steel mesh 17 at the top of the bottom plate can improve the structural strength at the chamfered structure at the bottom of the holes.

[0082] Preferably, the bottom plate top chamfered steel mesh 17 is installed before the inner support frame is installed. The inner support frame is provided with a first mating surface that contacts the bottom plate top chamfered steel mesh 17. Thus, the bottom plate top chamfered steel mesh 17 can provide support for the inner support frame. At the same time, the inner support frame can check the positional accuracy of the bottom plate top chamfered steel mesh 17 and ensure the consistency of the steel reinforcement modules.

[0083] It should be noted that installing the bottom plate top chamfered steel mesh 17 before installing the inner support frame can avoid inserting the bottom plate top chamfered steel mesh 17 in the limited space between the inner support frame and the bottom plate steel cage 13, which facilitates the assembly of the bottom plate top chamfered steel mesh 17 and improves the production efficiency of the steel module.

[0084] According to some embodiments of the present invention, the box girder construction method further includes:

[0085] Before placing the bottom steel mesh 15 of the top slab on the top of the inner support frame, install two bottom chamfered steel meshes 18 of the top slab to both sides of the inner mesh assembly.

[0086] In some embodiments, the top of the inner mesh assembly is further provided with a second mating surface suitable for contacting the bottom chamfered steel mesh 18 of the top plate. The second mating surface can provide support and positioning for the bottom chamfered steel mesh 18 of the top plate. At the same time, installing the bottom chamfered steel mesh 18 of the top plate before installing the bottom chamfered steel mesh 15 of the top plate can avoid inserting the bottom chamfered steel mesh 18 of the top plate in the limited space between the bottom chamfered steel mesh 15 of the top plate and the inner mesh assembly, which facilitates the assembly of the bottom chamfered steel mesh 18 of the top plate and improves the production efficiency of the steel module.

[0087] Connect one end of the two top slab bottom chamfered steel meshes 18 on the same side to the two web steel cages 14 respectively.

[0088] After the bottom steel mesh 15 of the top slab is placed on the top of the inner support frame, the other ends of the two bottom chamfered steel meshes 18 of the top slab are connected to the bottom steel mesh 15 of the top slab respectively.

[0089] It is understandable that after installing the bottom chamfered steel mesh 18 of the top slab, the bottom chamfered steel mesh 18 of the top slab is first connected to the web steel cage 14, and then the bottom steel mesh 15 of the top slab is installed. After the bottom steel mesh 15 of the top slab is installed, the bottom chamfered steel mesh 18 of the top slab is connected to the bottom steel mesh 15 of the top slab.

[0090] Therefore, by adopting the above-mentioned bottom-up assembly method, the assembly steps of the steel bar module of this application can be made clearer, the sense of hierarchy in the production of steel bar modules can be improved, and the production efficiency of steel bar modules can be increased.

[0091] Please refer to some embodiments of the present invention. Figure 2 , Figure 3 and Figure 10 The third reinforcing steel unit includes a top slab reinforcing steel mesh 19. A third reinforcing steel unit connected to the second reinforcing steel unit is provided at the top of the inner support frame, including:

[0092] Install the top steel mesh 19 of the top slab to the top of the inner support frame.

[0093] Connect the top slab reinforcement mesh 19 to the two web reinforcement cages 14.

[0094] In some embodiments, after the bottom steel mesh 15 of the top slab is installed, the top steel mesh 19 of the top slab is installed on the top of the inner support frame, and then the top steel mesh 19 of the top slab is connected to the two web steel cages 14 to complete the assembly of the top steel mesh 19 of the top slab.

[0095] According to some embodiments of the present invention, the third reinforcing bar unit includes a top reinforcing bar mesh 20 of the flange plate, and a third reinforcing bar unit connected to the second reinforcing bar unit is provided at the top of the inner support frame, and further includes:

[0096] Install the two flange plate top steel mesh 20 to the two sides of the top plate top steel mesh 19 respectively.

[0097] Connect the top steel mesh 20 of the two flange plates to the bottom steel mesh 16 of the flange plates and the top steel mesh 19 of the top plate, respectively.

[0098] In some embodiments, after the top plate top steel mesh 19 is assembled, two flange plate top steel meshes 20 are installed on both sides of the top plate top steel mesh 19, then the top plate top steel mesh 19 and the two flange plate top steel meshes 20 are connected, and finally the two flange plate top steel meshes 20 are connected to the two flange plate bottom steel meshes 16, thereby completing the assembly of the flange plate top steel mesh 20.

[0099] It is worth mentioning that the bottom reinforcement mesh 16 and the top reinforcement mesh 20 of the flange plate correspond to the flange plate structure of the box girder.

[0100] Please refer to some embodiments of the present invention. Figures 4-7The end faces of multiple steel reinforcement modules are arranged parallel to each other. The multiple steel reinforcement modules include a first module 31, a second module 32 and a third module 33 respectively. The number of the first module 31, the second module 32 or the third module 33 can be set as needed. The two ends of the first module 31 can be selectively connected to the second module 32, and the end of the second module 32 facing away from the first module 31 can be selectively connected to the third module 33.

[0101] In some embodiments, the end faces of multiple steel reinforcement modules are arranged parallel to each other. Preferably, the longitudinal steel bars of each steel reinforcement module do not protrude from the end face of the steel reinforcement module, so that the end face of each steel reinforcement module is a flat section. This makes it easy to install multiple steel reinforcement modules into the outer formwork, avoids interference between the steel bars of the box girder steel reinforcement modules, improves the installation efficiency of the steel reinforcement modules, and thus improves the construction efficiency of the box girder.

[0102] In other embodiments, the multiple steel reinforcement modules include a first module 31, a second module 32, and a third module 33, respectively. The length of the first module 31 is greater than the lengths of the second module 32 and the third module 33. A box girder segment includes one first module 31, two second modules 32, and two third modules 33. The two ends of the first module 31 are respectively connected to the two second modules 32. The ends of the two second modules 32 that are away from the first module 31 are respectively connected to the third module 33. Two adjacent box girder segments are connected by the two third modules 33.

[0103] It is worth mentioning that the number of the first module 31, the second module 32, and / or the third module 33 can be increased or decreased according to the actual situation on site (such as the distance between bridge piers). When there are multiple first modules 31, one end of the first module 31 located at the end is connected to the second module 32 or the third module 33, and the other end is connected to the adjacent first module 31. The two ends of the first module 31 located in the middle are respectively adapted to be connected to two adjacent first modules 31.

[0104] According to some embodiments of the present invention, before pouring concrete inside the outer formwork, the method further includes: inserting pull rods or corrugated pipes inside the first module 31, the second module 32 and the third module 33.

[0105] Understandably, box girders, as large-span structures, need to withstand significant loads. Applying prestress can effectively improve the structure's load-bearing capacity and crack resistance. The use of pull rods or corrugated pipes within the steel reinforcement modules in this application serves as pre-reserved channels for prestressing tendons. These pre-reserved channels are the pathways for the arrangement and tensioning of prestressing tendons; only by pre-setting these channels can the prestressing construction process be successfully implemented.

[0106] It is worth mentioning that the pull rod has good rigidity and a certain degree of flexibility, which allows it to maintain its shape stability during concrete pouring, ensuring the accuracy of the size and position of the reserved channels. Once the concrete reaches a certain strength, the pull rod can be pulled out, forming a smooth channel. The corrugated pipe not only serves as a reserved channel but also provides some protection for the internal prestressing tendons, preventing them from directly contacting the concrete and being corroded.

[0107] According to some embodiments of the present invention, the prestressed steel strands are tensioned after the concrete inside the outer formwork has solidified.

[0108] After the concrete is poured and hardened, the prestressed steel strands are tensioned to generate a prestress on the surrounding concrete. This prestress can offset some of the tensile stress that the structure experiences during use, thereby delaying the appearance and development of concrete cracks and improving the crack resistance of the box girder.

[0109] Understandably, multiple prestressed steel strands are distributed circumferentially along the inner support frame. These multiple prestressed steel strands can distribute the prestress evenly or according to design requirements into the concrete. When the structure is subjected to load, the prestressed steel strands transfer the prestress to the concrete through bonding with it, putting the concrete in a state of compression. At the same time, this balances the tensile stress generated by the load, improving the stress distribution of the box girder structure and enhancing its overall load-bearing capacity.

[0110] The above description is merely a preferred embodiment of the present invention and is not intended to limit the 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.

[0111] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for constructing box girders, characterized in that, include: Multiple first steel reinforcement units, multiple second steel reinforcement units, and multiple third steel reinforcement units are prefabricated simultaneously in the factory. Multiple first steel bar units are placed on a jig (1) in the factory, and a first connecting steel bar (11) is inserted at the intersection of multiple first steel bar units. The first connecting steel bar (11) is connected to multiple first steel bar units to form a bottom steel bar assembly with an open top. Install the inner support frame into the bottom steel reinforcement assembly; Second steel reinforcement units connected to the bottom steel reinforcement assembly are respectively provided on both sides and the top of the inner support frame. Second connecting steel reinforcement (12) is inserted at the intersection of the bottom steel reinforcement assembly and part of the second steel reinforcement units, and the second connecting steel reinforcement (12) is connected to the bottom steel reinforcement assembly and the second steel reinforcement units. A third steel reinforcement unit connected to the second steel reinforcement unit is provided on the upper part of the second steel reinforcement unit. The first steel reinforcement unit, the second steel reinforcement unit and the third steel reinforcement unit together constitute a steel reinforcement module. Multiple steel reinforcement modules are placed sequentially along the longitudinal direction of the box girder inside the outer formwork at the construction site; Concrete is poured inside the outer formwork.

2. The box girder construction method according to claim 1, characterized in that, The plurality of first reinforcing bar units respectively include a bottom slab reinforcing cage (13) and a web reinforcing cage (14), and the process of forming a bottom reinforcing bar assembly with an open top includes: Place the bottom plate steel reinforcement cage (13) on the frame (1); Two web reinforcement cages (14) are installed at both ends of the bottom plate reinforcement cage (13), and the ends of the two web reinforcement cages (14) are inserted into the first receiving space at both ends of the bottom plate reinforcement cage (13). The first connecting steel bar (11) is inserted into the first containment space. Connect the first connecting steel bar (11), the bottom plate steel cage (13), and the web plate steel cage (14).

3. The box girder construction method according to claim 2, characterized in that, Multiple second reinforcement units respectively include a top slab bottom reinforcement mesh (15) and a flange slab bottom reinforcement mesh (16), and when multiple second reinforcement units are provided, they include: The bottom steel mesh (16) of the flange plate is set on both sides of the inner support frame. The two bottom steel meshes (16) of the flange plate are respectively supported on the frame (1) and respectively connected to the two web steel cages (14). The bottom steel mesh (15) of the top slab is placed on the top of the inner support frame, and the free ends of the two web steel cages (14) are inserted into the second receiving space at both ends of the bottom steel mesh (15). A second connecting steel bar (12) is inserted into the second containment space; Connect the second connecting steel bar (12), the top slab bottom steel mesh (15), and the web steel cage (14).

4. The box girder construction method according to claim 3, characterized in that, Before installing the second steel reinforcement unit, the following is also included: Install two bottom plate top chamfered steel meshes (17) into the bottom steel reinforcement assembly; Connect one end of the two bottom plate top chamfered steel meshes (17) on the same side to the bottom plate steel cage (13), and connect the other end of the two bottom plate top chamfered steel meshes (17) on the same side to the two web steel cages (14).

5. The box girder construction method according to claim 3, characterized in that, Also includes: Before setting the bottom steel mesh (15) of the top plate on the top of the inner support frame, install two bottom chamfered steel meshes (18) of the top plate to both sides of the inner mesh assembly; Connect one end of the two top slab bottom chamfered steel meshes (18) on the same side to the two web steel cages (14); After the bottom steel mesh (15) of the top slab is placed on the top of the inner support frame, the other ends of the two bottom chamfered steel meshes (18) of the top slab are connected to the bottom steel mesh (15) of the top slab respectively.

6. The box girder construction method according to claim 5, characterized in that, The third reinforcing steel unit includes a top slab reinforcing steel mesh (19), and the third reinforcing steel unit, which is connected to the second reinforcing steel unit and is located at the top of the inner support frame, includes: Install the top steel mesh (19) of the top slab to the top of the inner support frame; Connect the top slab reinforcement mesh (19) to the two web reinforcement cages (14).

7. The box girder construction method according to claim 6, characterized in that, The third reinforcing bar unit includes a top reinforcing bar mesh (20) of the flange plate. The third reinforcing bar unit, which is connected to the second reinforcing bar unit and is located at the top of the inner support frame, further includes: Install the two flange top steel meshes (20) to both sides of the top steel mesh (19) of the top plate; Connect the top reinforcement mesh (20) of the two flange plates to the bottom reinforcement mesh (16) of the flange plates and the top reinforcement mesh (19) of the top plate, respectively.

8. The box girder construction method according to claim 1, characterized in that, The end faces of the multiple steel reinforcement modules are arranged parallel to each other. The multiple steel reinforcement modules include a first module (31), a second module (32), and a third module (33). The number of the first module (31), the second module (32), or the third module (33) can be set as needed. The two ends of the first module (31) can be selectively connected to the second module (32) or the third module (33), and the end of the second module (32) facing away from the first module (31) can be selectively connected to the third module (33).

9. The box girder construction method according to claim 8, characterized in that, Before pouring concrete into the outer formwork, the method further includes inserting pull rods or corrugated pipes into the first module (31), the second module (32), and the third module (33).

10. The box girder construction method according to claim 1, characterized in that, After the concrete inside the outer formwork has solidified, the prestressed steel strands are tensioned.

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