A rigid frame arch bridge concrete formwork system and a construction method thereof

Abstract

The present application relates to the technical field of construction technology of outer concrete of rigid skeleton concrete arch bridge, and particularly relates to a rigid skeleton arch bridge outer concrete formwork system and a construction method thereof. The formwork system is designed with corresponding formwork components for the roof, web and roof respectively. A construction channel is formed through the bottom plate bottom die. The steel formwork matches the arch rib line type. The large block formwork structure improves the web formwork splicing quality, reduces the installation difficulty of the web outer side form, reduces the arch construction risk and difficulty, improves the arch construction efficiency, improves the formed concrete surface quality. Meanwhile, the connection between the formwork and the rigid skeleton is realized through the pull rod structure, so that the formwork installation stability is good, the installation precision is high, the force applied to the formwork during the concrete pouring process can be effectively transmitted to the rigid skeleton, the overall line type quality of the formed arch bridge is improved. The construction method realizes the turnover use of the formwork system by preparing multiple sets of formwork systems, reduces the preparation cost of the formwork system, and improves the construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of concrete encasing construction technology for rigid frame concrete arch bridges, and particularly to a formwork system for concrete encasing rigid frame arch bridges and its construction method. Background Technology

[0002] Since its invention in 1898, the span of rigid-frame concrete arch bridges has been increasing at an average rate of 1.5m per year. Due to its advantages such as high stiffness, insensitivity to daily temperature differences, good durability, and reasonable cost, building rigid-frame concrete arch bridges with larger spans has become the primary choice for shortening time and space distances.

[0003] For rigid-frame concrete arch bridges, after the steel pipe truss or concrete-filled steel pipe is constructed, the steel pipe truss or concrete-filled steel pipe is used as the main load-bearing component, and external formwork is used for the pouring of the outer concrete. However, the load-bearing capacity of the steel pipe truss or concrete-filled steel pipe arch structure is limited. For large-span rigid-frame arch bridges, the outer concrete has a large proportion of weight, and it is impossible to complete the concrete loading in one go. Generally, it is necessary to pour the concrete in three rings: bottom slab, web slab, and top slab. The concrete rings are constructed first, and together with the rigid frame, they form a new load-bearing structure to provide support for the subsequent construction stages.

[0004] Compared to the mature formwork systems and working platforms available for piers and box girders, the construction of the outer concrete cladding for rigid frame concrete arch bridges lacks a mature formwork system and cannot utilize scaffolding methods. The outer concrete cladding is constructed at high altitudes on near-45° slopes, resulting in a narrow working area and significant operational difficulties. As the span of the arch bridge increases, the design and installation of the formwork becomes increasingly complex, safety risks rise, and the stability and operability of the formwork deteriorate. Quality and safety issues such as formwork bulging and bursting frequently occur during construction, affecting the concrete appearance quality and alignment of the rigid frame concrete arch bridge and impacting construction efficiency.

[0005] Therefore, there is an urgent need for a technical solution to address the technical problems of the lack of a mature formwork system for the construction of the outer concrete cladding of existing rigid frame concrete arch bridges, the poor stability and operability of existing formwork systems, which increase the difficulty of construction and affect the quality and efficiency of construction. Summary of the Invention

[0006] The purpose of this invention is to address the technical problems of the lack of a mature formwork system for the construction of concrete cladding on rigid frame arch bridges, the poor stability and operability of existing formwork systems, which increase construction difficulty and affect construction quality and efficiency. This invention provides a formwork system for concrete cladding on rigid frame arch bridges and its construction method.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A reinforced concrete formwork system for a rigid arch bridge includes a bottom slab ring formwork, a web slab ring formwork, and a top slab ring formwork.

[0009] The base plate ring formwork includes a base plate bottom formwork, base plate side formwork, base plate inner formwork, a first end formwork, and a first pressing formwork; the base plate bottom formwork forms construction channels on both sides of the arch rib in the transverse direction; the base plate side formwork includes steel formwork that matches the shape of the space to be poured; the base plate inner formwork is connected to the base plate side formwork by tie rods; the base plate ring formwork is connected to the stiffening frame by tie rod structure; the web plate ring formwork includes a web plate outer formwork, a web plate inner formwork, a second end formwork, and a second pressing formwork; the web plate outer formwork includes several forms matching the height of the web plate to be poured in the arch cross-section. The outer template unit consists of several outer template units spliced ​​together along the longitudinal direction of the arch rib to match the arch rib line; the inner web template includes a loosely assembled template; the outer web template and the inner web template are connected by tie rods; the second pressing mold is reused with the first pressing mold; the top plate ring template includes a top plate inner template, a top plate pressing mold, a top plate side template, and a third end template; the top plate inner template is reused with the bottom plate inner template; the top plate side template is reused with the bottom plate side template; the third end template is reused with the first end template; the top plate ring template is connected to the stiffening frame through a tie rod structure.

[0010] This invention discloses a reinforced concrete formwork system for an arch bridge with a stiffened frame. Corresponding formwork components are designed for the top slab, web slab, and other sections. The bottom slab ring formwork forms a construction channel through the bottom formwork, facilitating other construction processes within the formwork system, reducing construction risks and difficulties on the arch, and improving construction efficiency. The bottom slab side formwork accurately matches the arch rib shape through its steel template, improving the quality of the formed arch rib shape. The outer formwork units of the web slab ring formwork are relatively high, forming a large-block formwork structure. This reduces the vertical splicing process of the web slab ring formwork on the arch, improves the splicing quality of individual formwork, enhances the surface quality of the formed concrete, reduces the installation difficulty of the outer web slab formwork, and improves the construction efficiency of the web slab ring formwork. The top slab ring formwork is reused with the bottom slab ring formwork, ensuring consistent forming quality for both the top and bottom slabs and reducing the overall manufacturing cost of the formwork system. Furthermore, the connection between each formwork and the stiffened frame is achieved through a tie rod structure, ensuring good installation stability and high installation accuracy. It also effectively transmits the force applied to the formwork during concrete pouring to the stiffened frame, improving the overall linear quality of the formed arch bridge.

[0011] In a preferred embodiment of the present invention, the bottom formwork of the base plate is fixed to the lower chord tube of the rigid frame by a plurality of U-shaped tie rods. A limiting block is provided between the bottom formwork of the base plate and the lower chord tube corresponding to the U-shaped tie rods. The limiting block is connected to the lower chord tube by steel bars passing through it along the axial direction of the lower chord tube. By limiting the distance between the bottom formwork of the base plate and the bottom surface of the rigid frame, the accuracy of the thickness of the outer concrete base plate is ensured. Simultaneously, the vertical alignment and arrangement of the steel bars, U-shaped tie rods, and limiting blocks achieves an effective and stable connection between the bottom formwork of the base plate and the rigid frame. This ensures the effective transfer of the stress on the formwork to the rigid frame during concrete pouring, guarantees the installation stability of the formwork system, and improves the quality and uniformity of the formed arch rib shape.

[0012] As a preferred embodiment of the present invention, the bottom formwork includes several bottom formwork units spliced ​​together along the longitudinal direction of the arch rib. A steel longitudinal beam is disposed at the center of the bottom longitudinal direction of each bottom formwork unit. The steel longitudinal beam is connected to the rigid frame horizontal connecting rod via a tie rod structure. Adjacent bottom formwork units are connected by embedded longitudinal connecting steel sections. This improves the installation stability of the bottom formwork and enables force transfer between adjacent bottom formwork units, achieving uniform distribution of stress on the formwork.

[0013] As a preferred embodiment of the present invention, the outer template unit includes a first type of template formed by cutting the top edge of a rectangular template unit according to the arch rib shape, and a second type of template formed by cutting the top edge of the rectangular template unit and the side edge of the arch top. Several of the first type and the second type of templates are alternately arranged along the longitudinal direction of the arch rib. By combining the first and second type of templates after cutting, an effective match between the web ring template and the arch rib shape is achieved, improving the smoothness and aesthetics of the formed concrete surface.

[0014] In a preferred embodiment of the present invention, the first end mold includes a steel end mold and a wooden end mold. The steel end mold is held in place by the main chord tube of the rigid frame, and the wooden end mold is flush with the steel end mold. The first end mold has steel back ribs attached to the top and bottom surfaces of the main chord tube, respectively. The steel end mold is connected to the outer wall of the main chord tube via a tie rod structure passing through the steel back ribs, and the wooden end mold is connected to the web members of the rigid frame via a tie rod structure. The steel end mold can closely fit the main chord tube. The combination of the steel and wooden end molds reduces the overall weight and manufacturing cost of the end molds, facilitates high-altitude installation on the arch, improves construction efficiency, reduces construction risks, and achieves a circumferential seal with the main chord tube through the steel end mold, preventing grout leakage and improving construction quality.

[0015] As a preferred embodiment of the present invention, the first mold includes a comb plate, a pressure plate component, a wedge block, and a limiting component. The comb plate holds the web reinforcement, the pressure plate component is fitted onto the top surface of the comb plate, the limiting component is welded to the web reinforcement fixedly connected to the stiffening frame, and the wedge block is wedged between the limiting component and the pressure plate component. A plurality of first mold segments are arranged to form discharge vibration holes between adjacent first molds. The comb plate can fit against the web reinforcement, achieving circumferential sealing of the web reinforcement and avoiding bulging and grout leakage at the web reinforcement protrusion positions. At the same time, the segmented first mold can quickly match the arch rib curve shape, improve the quality of the formed arch rib shape, and increase the flexibility of the first mold setting. It can effectively avoid the existing structure of the stiffening frame, improve the stability of the mold, and form discharge vibration holes, providing convenience for concrete vibration and ensuring the quality of concrete pouring.

[0016] As a preferred embodiment of the present invention, it further includes a horizontal connecting template, which comprises an outer horizontal connecting template and an inner horizontal connecting template. The outer horizontal connecting template includes a bottom horizontal connecting template, an arch crown side outer template, an arch foot side outer template, and a top horizontal connecting template. The arch crown side outer template includes a first outer template and a second outer template arranged sequentially from bottom to top along the height direction. The first outer template, the bottom horizontal connecting template, and the arch foot side outer template form an L-shaped template. The L-shaped template can be pre-assembled and connected to the stiffening frame segment to be hoisted. By forming the L-shaped template, the ground installation of the horizontal connecting template is facilitated, the installation difficulty of the horizontal connecting template is reduced, and the construction quality of the concrete covering of the stiffening frame horizontal connecting is improved.

[0017] A construction method for a rigid frame arch bridge external concrete formwork system is disclosed. The arch rib is longitudinally symmetrically divided into several pouring sections. The total pouring time of each pouring section is controlled within the initial setting time of the concrete. At least one set of the rigid frame arch bridge external concrete formwork system as described above is prepared for each pouring section and is symmetrically installed, poured, and rotated along both banks of the arch rib. Each formwork system is installed and poured in sequence according to the bottom plate, web plate, and top plate.

[0018] This invention discloses a construction method for a reinforced arch bridge external concrete formwork system. By preparing multiple sets of formwork systems, each set can be reused to meet the segmented construction requirements of the arch rib, thereby improving construction efficiency and ensuring the quality of the external concrete shape of each construction segment of the arch rib. At the same time, each set of formwork systems can be reused for the bottom slab ring formwork and the top slab ring formwork according to the actual situation, realizing the reuse of the formwork system by ring, segment, and working surface, reducing the formwork system preparation cost and improving construction efficiency.

[0019] As a preferred embodiment of the present invention, the bottom formwork and / or L-shaped formwork are pre-assembled and connected to the stiffening frame segments to be hoisted. These segments are then hoisted to their intended positions, and the formwork at the segment connections is then fitted in place. The outer formwork units are assembled on the ground and then hoisted onto the arch for installation, followed by the assembly and installation of the inner web formwork. The inner top formwork is suspended and assembled inside the arch box using lifting equipment erected above the top top formwork. A construction platform is set at the bottom of the inner top formwork, creating a passageway through the arch box below the platform. By rationally planning the installation sequence and method of each formwork, a reasonable coordination between ground assembly and arch installation is achieved, reducing the difficulty of construction on the arch and improving construction quality and efficiency.

[0020] As a preferred embodiment of the present invention, several first transverse channels are reserved during the pouring of the base slab; before the installation of the web ring formwork, first limiting rods are inserted into the first transverse channels to support the web ring formwork; during the pouring of the web, several second transverse channels are reserved; before the installation of the top ring formwork, second limiting rods are inserted into the second transverse channels to support the top ring formwork. By fully combining the principle of ring-by-ring pouring, the installation stability of the web ring formwork and the top ring formwork is ensured, thereby improving the overall construction quality of the formwork system.

[0021] In summary, due to the adoption of the above technical solutions, the beneficial effects of the rigid frame arch bridge external concrete formwork system of the present invention are:

[0022] 1. The bottom slab ring formwork forms a construction channel through the bottom formwork of the bottom slab, which facilitates other construction processes of the formwork system, reduces the risk and difficulty of construction on the arch, and improves the efficiency of construction on the arch;

[0023] 2. The bottom plate side mold accurately matches the shape of the arch rib through its steel template, thereby improving the quality of the formed arch rib shape;

[0024] 3. The outer formwork unit of the web ring formwork is relatively high, forming a large formwork structure. This can reduce the vertical splicing process on the arch of the web ring formwork, improve the splicing quality of individual formwork, improve the surface quality of the formed concrete, reduce the installation difficulty of the outer formwork of the web, and improve the construction efficiency of the web ring formwork.

[0025] 4. The top plate ring template can be reused with the bottom plate ring template to ensure that the top plate and bottom plate have the same forming quality, and it also helps to reduce the overall manufacturing cost of the template system.

[0026] 5. The connection between each template and the rigid frame is achieved through the tie rod structure, which not only makes the template installation stable and accurate, but also allows the force applied to the template during the concrete pouring process to be effectively transferred to the rigid frame, thereby improving the overall linear quality of the formed arch bridge.

[0027] The beneficial effects of the construction method of the rigid frame arch bridge external concrete formwork system of the present invention are:

[0028] 1. By preparing multiple sets of template systems, each set of template systems can be used to meet the segmented construction requirements of the arch rib, thereby improving construction efficiency and ensuring the quality of the outer concrete shape of each construction segment of the arch rib.

[0029] 2. When using each set of template systems, the bottom plate ring template and the top plate ring template can be reused according to the actual situation, thereby reducing the preparation cost of the template system. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the bottom plate ring template described in this invention;

[0031] Figure 2 This is a partial structural schematic diagram of the base plate ring template described in this invention;

[0032] Figure 3 This is a schematic diagram of the assembly structure of the bottom plate and bottom mold described in this invention;

[0033] Figure 4 This is a schematic diagram of the structure of the limiting block described in this invention;

[0034] Figure 5 This is a schematic diagram of the web ring template described in this invention;

[0035] Figure 6 This is a schematic diagram of the structure of the outer web mold described in this invention;

[0036] Figure 7 This is a schematic diagram of the cutting structure of a type of template described in this invention;

[0037] Figure 8 This is a schematic diagram of the cutting structure of the two types of templates described in this invention;

[0038] Figure 9 This is a schematic diagram of the top plate ring template described in this invention;

[0039] Figure 10 This is a schematic diagram of the installation process of the top plate inner mold described in this invention. Figure 1 ;

[0040] Figure 11 yes Figure 10 Enlarged structural diagram at point A;

[0041] Figure 12 This is a schematic diagram of the installation process of the top plate inner mold described in this invention. Figure 2 ;

[0042] Figure 13 This is a schematic diagram of the installation process of the top plate inner mold described in this invention. Figure 3 ;

[0043] Figure 14 This is a schematic diagram of the structure of the first end mold in this invention;

[0044] Figure 15 This is a schematic diagram of the combined structure of the steel end mold and the wooden end mold described in this invention;

[0045] Figure 16 This is a schematic diagram of the fixing structure of the steel end mold described in this invention;

[0046] Figure 17 This is a schematic diagram of the fixing structure of the first end mold in this invention;

[0047] Figure 18 This is a schematic diagram of the structure of the first compression mold in this invention;

[0048] Figure 19 This is a schematic diagram of the comb plate described in this invention;

[0049] Figure 20 This is a schematic diagram of the installation state structure of the first compression mold in this invention;

[0050] Figure 21 This is a schematic diagram of the structure of the cross-connecting template described in this invention;

[0051] Figure 22 This is a schematic diagram of the installation state structure of the L-shaped template described in this invention.

[0052] icon:

[0053] 10-Bottom plate ring formwork, 101-Bottom plate bottom formwork, 1011-Bottom formwork unit, 1012-Steel longitudinal beam, 1013-Longitudinal connecting steel, 102-Bottom plate side formwork, 103-Bottom plate inner formwork, 104-Construction passage, 105-U-shaped tie rod, 106-Limiting block, 1061-Reinforcing bar, 107-First limiting rod;

[0054] 20-Web ring template, 201-Outer web template, 202-Inner web template, 203-Outer template unit, 204-Class I template, 205-Class II template, 206-Second transverse channel, 207-Second limiting rod, 208-Cutting line;

[0055] 30-Top slab ring formwork, 301-Top slab inner formwork, 302-Top slab pressing formwork, 303-Top slab side formwork, 304-Lifting tools, 305-Construction platform, 306-Arch box passageway;

[0056] 40-First end mold, 401-Steel end mold, 402-Wooden end mold, 403-Steel back rib;

[0057] 50-First pressing mold, 501-Comb plate, 502-Pressure plate component, 5021-Pressure plate, 5022-Longitudinal square timber, 5023-Transverse square timber, 503-Wedge block, 504-Limiting component;

[0058] 60-Strengthened frame, 601-Lower chord tube, 602-Horizontal connecting rod, 603-Web plate reinforcement, 604-Web member, 605-Upper chord tube;

[0059] 70-Horizontal connecting formwork, 701-Horizontal connecting outer formwork, 7011-Horizontal connecting bottom formwork, 7012-Arch top side outer formwork, 70121-First outer formwork, 70122-Second outer formwork, 7013-Arch foot side outer formwork, 7014-Horizontal connecting top formwork, 702-L-shaped formwork, 703-Horizontal connecting inner formwork;

[0060] 80-Tie rod structure. Detailed Implementation

[0061] The present invention will now be described in detail with reference to the accompanying drawings.

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0063] It should be noted that in this invention, the longitudinal description refers to the chord length direction of the arch rib, and the transverse description refers to the width direction of the arch rib.

[0064] Example 1

[0065] like Figures 1-22As shown, a rigid frame arch bridge external concrete formwork system is applied to the external concrete construction of a steel-concrete composite rigid frame arch bridge. The bridge is an upper-bearing rigid frame concrete arch bridge. The arch ring consists of two parallel arch ribs and inter-rib cross bracing. The arch crown section is 8m high, the arch foot section is 12m high, the rib width is 6.5m, the transverse center distance is 16.5m, the arch rib bottom plate thickness is 0.65-1.3m, the web plate thickness is 0.45-0.95m, and the top plate thickness is 0.65m. There are 16 cross bracings and 20 X-braces between the ribs. The arch box has 13 box-shaped cross diaphragms and 32 ordinary cross diaphragms, dividing it into 60 large box chambers and 39 small box chambers. The rigid frame 60 is assembled segmentally using cable hoisting and inclined clamping technology. The arch ribs are constructed using catenary... The variable cross-section structure design follows the overall construction sequence of reinforcement binding, formwork installation, and concrete pouring, employing a three-ring pouring process for the bottom slab, web, and top slab. Since the structures of the bottom slab, web, and top slab are different, separate bottom slab ring formwork 10, web ring formwork 20, and top slab ring formwork 30 are designed for the bottom slab, web, and top slab respectively. Both bottom slab ring formwork 10 and top slab ring formwork 30 need to extend to include a certain range of the arch rib web structure, ensuring that they completely encompass the arch rib chamfer section during installation and use. This ensures that the ring boundary line is inside the web and outside the chamfer, avoiding the node plate, simplifying the structure of the web ring formwork 20, facilitating the installation of each ring formwork, and improving the quality control of each ring in the bottom slab, web, and top slab.

[0066] Preferred, such as Figures 1-4 , Figure 17 As shown, the bottom plate ring template 10 forms a bottom plate casting space by enclosing the bottom plate mold 101, the bottom plate side mold 102, the bottom plate inner mold 103, the first end mold 40 and the first pressing mold 50. The first end mold 40 is used to close the end face of the bottom plate casting space in the longitudinal direction of the arch rib, and the first pressing mold 50 is used to close the top opening of the bottom plate casting space.

[0067] In some embodiments, the bottom mold 101 of the base plate adopts a standardized combination wooden mold, including bamboo plywood, wooden I-beams, and steel transverse distribution beams arranged sequentially in the thickness direction. The wooden I-beams are arranged at equal intervals and connected to the steel transverse distribution beams by conventional connecting claws. The steel transverse distribution beams are arranged at equal intervals and are assembled into the required shape and specifications before use. The inner mold 103 of the base plate has the same structure as the bottom mold 101 of the base plate and adopts a standardized combination wooden mold or a loosely assembled template structure.

[0068] In some embodiments, the length of the transverse steel distribution beam satisfies the following condition: both ends can extend a certain distance beyond the stiffening frame by 60 segments. By laying a conventional platform panel structure, construction channels 104 are formed on both sides of the transverse arch rib. This facilitates other construction procedures on the arch and reduces the construction risks on the arch.

[0069] Preferably, the bottom plate side formwork 102 includes a steel formwork that matches the shape of the space to be poured.

[0070] In some embodiments, the steel formwork is set as a rectangle, and the bottom and top plate lines are matched by adjusting the assembly gap of the steel formwork.

[0071] In this embodiment, for the construction of the outer concrete enclosure of a steel-concrete composite rigid frame arch bridge, a steel formwork with a length of 1.5m and a height of 2.2m is prepared. Tie rod holes are uniformly opened during the preparation of the steel formwork. After the steel formwork is assembled, the maximum gap of the outer arc is only 6mm, and the assembly quality is extremely high. The gap can be stably filled and sealed by the triangular grout stop plate. During assembly, the bottom of the steel formwork is fixedly connected by the vertical tie rod structure 80 through the transverse steel distribution beam of the bottom formwork 101 of the bottom plate. The bottom sides of the steel formwork located upstream and downstream of the arch rib are connected by the horizontal tie rod structure 80 or connected to the transverse steel reinforcement of the arch rib by the horizontal tie rod structure 80. The top side is connected to the inner formwork 103 of the bottom plate by the horizontal tie rod structure 80, so as to realize the connection between the steel formwork and the adjacent formwork structure.

[0072] Preferably, the bottom plate ring template 10 is connected to the rigid frame 60 via a tie rod structure 80.

[0073] In some embodiments, such as Figure 1 As shown, specifically, it includes: the transverse steel distribution beams that make up the bottom formwork 101 of the base plate are respectively hung and welded to the lower chord tube 601 of the stiffening frame 60 through U-shaped tie rods 105; the steel formwork is welded to the upper surface of the lower chord tube 601 along the tangent direction of the lower chord tube 601 through the inclined tie rod structure 80 extending from the chamfered section of the arch rib into the bottom plate pouring space; the transverse steel distribution beams that make up the inner formwork 103 of the base plate are respectively welded downward to the horizontal connecting rod 602 of the stiffening frame 60 through multiple vertical tie rod structures 80, and in conjunction with the anti-pull fixed connection of the two side formworks 102 of the base plate, the anti-pull fixed connection of the inner formwork 103 of the base plate and the side formwork 102 of the base plate, forming a stable tie rod system in the bottom plate pouring space, which is conducive to the stable distribution of the force on the bottom plate ring formwork 10 during the bottom plate pouring process and effectively transfer it to the stiffening frame 60, realizing the stable installation of the bottom plate ring formwork 10 on the stiffening frame 60, ensuring the structural stability of the bottom plate pouring space, and thus ensuring the quality of the formed outer concrete.

[0074] like Figures 5-8 As shown, preferably, the web ring template 20 forms a web casting space by enclosing the web outer mold 201, the web inner mold 202, the second end mold, and the second pressure mold. The second end mold is used to close the end face of the web casting space in the longitudinal direction of the arch rib, and the second pressure mold is used to close the top opening of the web casting space.

[0075] Preferably, the outer web mold 201 includes several outer template units 203 that match the height of the web to be poured in the arch section, and the several outer template units 203 are spliced ​​along the longitudinal direction of the arch rib to match the arch rib line; the inner web mold 202 includes loosely assembled templates; the outer web mold 201 and the inner web mold 202 are connected by horizontal tie rod structure 80; since the opening structure of the space to be poured and closed is similar to that faced by the first mold 50 and the second mold, the second mold has the same structure as the first mold 50 and can be reused. When reused, the structure and size are adjusted according to the actual installation position.

[0076] In some embodiments, the outer template unit 203 and the second end mold are both made of prefabricated combined wooden molds, which are assembled into the required shape and specifications before use, including a panel, a vertical distribution beam and a horizontal back rib arranged in sequence in the thickness direction. The panel is made of bamboo plywood, the vertical distribution beam is made of wooden I-beams, and the horizontal back rib is made of steel back rib. The wooden I-beams are arranged at equal intervals and are connected to the steel back ribs arranged at equal intervals by conventional connecting claws.

[0077] In some embodiments, the outer template unit 203 is formed by splicing multiple building template matrices to form a panel that matches the height to be poured in the web of the arch section.

[0078] In some embodiments, such as Figure 6 As shown, several outer template units 203 are hoisted to the installation position and installed. The longitudinally adjacent outer template units 203 are connected and fixed by several transverse steel components, preferably steel plates, to improve the integrity of the web outer template 201.

[0079] In this embodiment, for the construction of the outer concrete casing of a steel-concrete composite rigid frame arch bridge, nine 1.22m×2.44m WISA panels are assembled to form the panel. I-beams are used as vertical distribution beams, and double-sided channel steel is used as transverse back ribs. The WISA panels and I-beams are connected by floor nails, and the I-beams are connected to the transverse back ribs by connecting claws. The outer template unit 203 is assembled in a conventional template connection method to form a rectangular template unit, which can meet the current arch bridge web pouring height. During use, adjustments and edge trimming are made according to the actual situation to match the arch rib line for web pouring to the greatest extent.

[0080] like Figures 9-13 As shown, preferably, the top plate ring template 30 is formed by the top plate inner mold 301, the top plate pressing mold 302, the top plate side mold 303 and the third end mold to form the top plate casting space.

[0081] In this embodiment, for the construction of the outer concrete casing of a steel-concrete reinforced arch bridge, the top slab and the bottom slab have the same arch rib cross-section structure. Therefore, the materials of the inner formwork 301 of the top slab and the inner formwork 103 of the bottom slab are reused; the materials of the side formwork 303 of the top slab and the side formwork 102 of the bottom slab are reused; and the materials of the third end formwork and the first end formwork 40 are reused. During the reuse process, the model, material and structure of each formwork material are adjusted according to the actual situation.

[0082] Preferably, the top plate ring template 30 is connected to the rigid frame 60 via a tie rod structure 80.

[0083] In some embodiments, such as Figure 9 As shown, specifically, it includes: each steel transverse distribution beam constituting the inner mold 301 of the top plate is welded upward to the horizontal connecting rod 602 of the stiffening frame 60 through multiple vertical tie rod structures 80, and welded to the lower surface of the upper chord tube 605 along the tangent direction of the upper chord tube 605 through oblique tie rods; the side mold 303 of the top plate is welded to the lower surface of the upper chord tube 605 along the tangent direction of the upper chord tube 605 through tie rod structures 80 extending from the chamfered section of the arch rib into the casting space of the top plate, and obliquely extended and welded to the horizontal connecting rod 602 of the stiffening frame 60, realizing an upper-supporting tie rod fixing system relative to the upper chord tube 605; each of the steel transverse distribution beams constituting the inner mold 302 of the top plate is welded upward to the horizontal connecting rod 602 of the upper chord tube 605 through multiple vertical tie rod structures 80, and welded obliquely to the horizontal connecting rod 602 of the stiffening frame 605. The transverse distribution beam of the steel section is welded downwards to the horizontal connecting rod 605 of the stiffening frame 60 through multiple vertical tie rod structures 80, and is also welded downwards to the outer surface of the tangent of the upper chord tube 605 through the vertical tie rod structure 80. With the tie-fixed connection of the two top plate side molds 303 and the tie-fixed connection of the top plate inner mold 301 and the top plate side molds 303, a stable tie rod system is formed in the top plate pouring space. This is conducive to the stable distribution of the stress on the template during the top plate pouring process through the template structure and the effective transfer to the stiffening frame 60, so as to realize the stable installation of the top plate ring template 30 on the stiffening frame 60 and ensure the structural stability of the top plate pouring space.

[0084] This embodiment presents a reinforced concrete formwork system for an arch bridge with a stiffened frame. Corresponding formwork is designed for the top slab, web slab, and other sections. Each ring formwork, through its specific structure and fixing method, enhances installation stability, improves operability, reduces construction difficulty, and increases construction quality and efficiency. Specifically, it includes: the bottom slab ring formwork 10 forms a construction channel 104 through the bottom slab formwork 101, facilitating other construction processes within the formwork system, reducing the risk and difficulty of construction on the arch, and improving construction efficiency; the bottom slab side formwork 102 accurately matches the shape of the arch ribs through its steel formwork, improving the quality of the formed arch rib shape; the outer formwork unit 203 of the web slab ring formwork 20 has a higher height, forming a large-block formwork structure. This reduces the vertical splicing process on the web ring formwork 20, improves the splicing quality of individual formwork, enhances the surface quality of the formed concrete, reduces the installation difficulty of the outer web formwork 201, and improves the construction efficiency of the web ring formwork 20. The top slab ring formwork 30, through material reuse with the bottom slab ring formwork 10, ensures that the top and bottom slabs have the same forming quality and helps reduce the overall preparation cost of the formwork system. At the same time, by forming a stable tie rod system, the connection between each formwork and the stiffening frame 60 is realized, which not only makes the formwork installation stable and accurate, but also allows the force applied to the formwork during the concrete pouring process to be effectively transferred to the stiffening frame 60, improving the overall linear quality of the formed arch bridge.

[0085] Example 2

[0086] like Figures 1-4 As shown in this embodiment, a rigid frame arch bridge external concrete formwork system, based on embodiment 1, includes a bottom formwork 101 comprising several bottom formwork units 1011 spliced ​​together along the longitudinal direction of the arch rib. Each bottom formwork unit 1011 is a standardized combined wooden formwork. Adjacent bottom formwork units 1011 are connected by embedded longitudinal connecting steel sections 1013. Each bottom formwork unit 1011 is hung and welded to the lower chord tube 601 of the rigid frame 60 after being hung by multiple U-shaped tie rods 105 arranged at equal intervals along the longitudinal direction of the arch rib. A limiting block 106 is provided between the bottom formwork 101 and the lower chord tube 601 corresponding to the U-shaped tie rods 105. The limiting block 106 is provided with a reinforcing bar 1061 passing through it along the axial direction of the lower chord tube 601 and welded to the lower chord tube 601.

[0087] In some embodiments, the U-shaped tie rod 105 is made of round steel or threaded steel, with a threaded section at the end, and equipped with an anchor plate and double nuts. The U-shaped tie rod 105 is hung on the lower chord tube 601 and then welded. Before welding, it is beneficial to accurately adjust the relative position of the bottom plate formwork 101 and the lower chord tube 601 to ensure that the bottom plate forming line is better. After welding, it can stably maintain the relative positional relationship between the bottom plate formwork 101 and the stiffening frame 60, and effectively transfer the pressure applied to the bottom plate formwork 101 by the concrete pouring process to the stiffening frame 60, so as to improve the structural stability of the bottom plate formwork 101 during the construction of the outer concrete of the arch bridge, thereby improving the quality of the formed arch rib.

[0088] In some embodiments, the limiting block 106 is prepared and molded using concrete of the same grade as the outer concrete of the arch rib. After the outer concrete of the rigid frame is constructed, it is retained inside the outer concrete, realizing the combination of prefabrication and cast-in-place concrete of the bottom slab of the outer concrete of the rigid frame. The limiting block 106 restricts the relative positional relationship between the bottom formwork 101 of the bottom slab and the rigid frame 60, ensuring that the bottom formwork 101 of the bottom slab matches the line shape of the arch rib.

[0089] In some embodiments, the limiting block 106 includes an arc-shaped top surface to match the outer surface of the lower chord tube 601. During the prefabrication process, grooves are formed on the top and bottom surfaces of the limiting block 106, and a through groove is formed on the limiting block 106 to form a concrete passage between the limiting block 106 and the bottom mold 101 of the base plate. This facilitates the fixed connection between the limiting block 106 and the lower chord tube 601 by inserting reinforcing bars 1061. This ensures that the limiting block 106 is stable in position and not easily overturned during the pouring of the base plate concrete, and has a good degree of integration with the base plate concrete. This effectively avoids the formation of quality defects such as cavities and air bubbles in the base plate due to the setting of the limiting block 106, thereby ensuring the overall concrete forming quality of the base plate concrete.

[0090] In some embodiments, the steel transverse distribution beams, U-shaped tie rods 105 and limiting blocks 106 that make up the bottom formwork 101 are arranged vertically in a corresponding manner, preferably at equal intervals of 1m. The specific intervals can be adjusted according to the actual situation to achieve an effective and stable connection between the bottom formwork 101 and the rigid frame 60. This ensures that the force on the formwork during the concrete pouring process can be effectively distributed and transmitted to the rigid frame 60 along the force transmission path, guaranteeing the installation stability of the formwork system and improving the quality and uniformity of the formed arch rib shape.

[0091] Preferably, a steel longitudinal beam 1012 is provided at the longitudinal center of the bottom of each bottom formwork unit 1011. The steel longitudinal beam 1012 is welded upward to the horizontal connecting rod 602 of the stiffening frame 60 through a vertical tie rod structure 80. This improves the installation stability of the bottom formwork 101 and realizes the force distribution and transmission between adjacent bottom formwork units 1011, achieving uniform force distribution on the bottom ring formwork 10.

[0092] In some embodiments, the longitudinal connecting steel 1013 is installed on the same layer as the I-beam longitudinal beam.

[0093] This embodiment of a rigid frame arch bridge external concrete formwork system uses multiple bottom formwork units 1011 spliced ​​together to match the bottom surface line of the arch rib by folding instead of bending, thereby improving the quality of the concrete line of the bottom surface of the arch rib. At the same time, each bottom formwork unit 1011 is effectively connected to the rigid frame 60 to achieve stable distribution and transmission of the force on the bottom plate ring formwork 10, thereby improving the structural stability of the bottom plate ring.

[0094] Example 3

[0095] like Figures 5-8 As shown, this embodiment of a rigid frame arch bridge external concrete formwork system, based on embodiment 1, the outer formwork unit 203 includes a first type of formwork 204 formed by cutting the top edge of the rectangular formwork unit according to the arch rib line, and a second type of formwork 205 formed by cutting the top edge of the rectangular formwork unit and the side edge of the arch top. Several of the first type of formwork 204 and the second type of formwork 205 are alternately arranged along the longitudinal direction of the arch rib.

[0096] In some embodiments, nine 1.22m×2.44m WISA plates are assembled to form the panel of the outer template unit 203, resulting in a rectangular template unit with a width of 3.66m and a height of 7.32m. The height can meet the maximum height of the web of the arch ring section of the stiffened arch bridge currently under construction.

[0097] In some embodiments, such as Figure 6 As shown, rectangular formwork units are assembled on the ground and reinforced by setting vertical steel structures at three equal vertical divisions to improve the overall strength of a single rectangular formwork unit.

[0098] In some embodiments, after the rectangular template unit is assembled on the ground, it is positioned according to the required height and top edge profile of the installation location, such as... Figure 7 As shown, the top edge is cut along the cutting line 208 to form a template 204, which has the characteristics of an inclined top edge and right angles on both sides of the bottom that conform to the arch rib line.

[0099] In some embodiments, after the rectangular template unit is assembled on the ground, it is positioned according to the required height and top edge profile of the installation location, such as... Figure 8As shown, the top edge and the side edge of the arch are cut along the cutting line to form a second type of template 205, so that the second type of template 205 has the characteristics of an inclined top edge, an oblique side edge of the arch, and a right angle located at the bottom arch foot, which conform to the arch rib line.

[0100] In some embodiments, when the first type of template 204 and the second type of template 205 are reused, they are cut parallel to the previous cutting line 208 according to the usage requirements of the next installation position, forming the first type of template 204 and the second type of template 205 that meet the usage requirements of the next installation position, so as to realize the reuse of the outer web template 201 along the longitudinal direction of the arch rib.

[0101] In some embodiments, each outer template unit 203 is structurally reinforced along the cutting line 208 after each cutting. Preferably, the reinforcement along the cutting line 208 is carried out by adding steel back ribs to improve the structural strength of a single outer template unit 203.

[0102] This embodiment presents a rigid frame arch bridge external concrete formwork system. Type I formwork 204 and Type II formwork 205 are alternately arranged along the longitudinal direction of the arch rib, allowing for continuous changes in the alignment of the outer web formwork 201, achieving a good match with the arch rib alignment. This results in effective matching between the web ring formwork 20 and the arch rib alignment, improving the smoothness and aesthetics of the formed concrete surface. Furthermore, the system can quickly determine the installation accuracy of each outer formwork unit 203 based on its right-angle position, ensuring the formwork installation alignment is controllable and thus improving installation precision. It also shortens the time required for construction personnel to match the formwork to the arch rib alignment on-site, improving construction convenience and efficiency.

[0103] Example 4

[0104] like Figures 14-17 As shown in this embodiment, a rigid frame arch bridge external concrete formwork system, based on embodiment 1, includes a first end mold 40 comprising a steel end mold 401 and a wooden end mold 402. The steel end mold 401 is held in place by the main chord tube of the rigid frame 60 and welded to the main chord tube. The wooden end mold 402 is flush with the steel end mold 401. The first end mold 40 is fitted with steel back ribs 403 on the top and bottom surfaces of the main chord tube, respectively. The steel end mold 401 is connected to the outer wall of the main chord tube by a tie rod structure 80 passing through the steel back ribs 403. The wooden end mold 402 is connected to the web members 604 of the rigid frame 60 by the tie rod structure 80.

[0105] In some embodiments, the first end mold 40 includes a fixed combination steel and wood template, and two steel end molds 401 are installed on the main chord tube by prefabricating two slotted steel plates. Bamboo plywood is provided between the two steel end molds 401 and on top, and the bamboo plywood is flush with the steel end molds 401 to form an end mold panel that matches the shape of the longitudinal end of the space to be poured in the bottom plate.

[0106] In some embodiments, a steel back rib 403 for fixing the steel end mold 401 is flush with the top and bottom surfaces of the main chord tube on the side of the end mold panel away from the space to be poured, and a steel back rib 403 for fixing the wooden end mold 402 is provided parallel to the top surface of the wooden end mold 402. The steel end mold 401 is welded to the outer wall of the main chord tube by a curved tie rod structure 80 passing through the corresponding steel back rib 403, and the wooden end mold 402 is welded to the web member 604 of the stiffening frame 60 by a horizontal tie rod structure 80 passing through the corresponding steel back rib 403.

[0107] In some embodiments, such as Figure 17 As shown, the stiffening frame 60 web members 604 used to fix the wooden end mold 402 are welded with vertical channel steel components to increase the connection stability of the tie rod structure 80.

[0108] This embodiment presents a reinforced frame arch bridge external concrete formwork system. The steel end mold 401 can be welded and closely fitted to the main chord tube to ensure that the force of the steel end mold 401 is effectively transferred to the reinforced frame. At the same time, the steel end mold 401 and the wooden end mold 402 work together to reduce the overall weight and preparation cost of the end molds, facilitate high-altitude installation on the arch, improve construction efficiency, reduce construction risks, and achieve a circumferential seal with the main chord tube through the steel end mold 401 to avoid grout leakage and improve construction quality.

[0109] Example 5

[0110] like Figures 18-20 As shown in this embodiment, a rigid frame arch bridge external concrete formwork system, based on embodiment 1, includes a first pressing mold 50 comprising a comb plate 501, a pressing plate component 502, a wedge block 503, and a limiting component 504. The comb plate 501 is held in place by the web reinforcement 603, the pressing plate component 502 is fitted onto the top surface of the comb plate 501, the limiting component 504 is welded to the web reinforcement 603 which is fixedly connected to the rigid frame 60, and the wedge block 503 is wedged between the limiting component 504 and the pressing plate component 502.

[0111] In some embodiments, the comb plate 501 includes a steel comb plate or a wooden comb plate. This embodiment uses a steel comb plate as an example for illustration. Figure 19 As shown, the comb plate 501 includes a plate-shaped structural member that is generally in the shape of a comb, including a comb tooth side and a comb back side. The comb tooth side includes a number of comb teeth arranged in parallel. The number of comb teeth are arranged in a manner that forms a clamping gap between adjacent comb teeth that is adapted to the outer diameter of the web reinforcement 603.

[0112] In some embodiments, such as Figure 18 As shown, the two comb-tooth plates 501 are arranged opposite each other to achieve separate clamping of the double-row web reinforcement 603.

[0113] In some embodiments, the pressure plate member 502 includes a pressure plate 5021, a longitudinal square timber 5022, and a transverse square timber 5023 arranged sequentially from bottom to top. The limiting member 504 includes a U-shaped steel bar, which is welded to the longitudinally adjacent or close web reinforcement 603. A gap is formed between the transverse square timber 5023 and the U-shaped steel bar for the wedge block 503 to be wedged in. The wedge block 503 is preferably a wooden block with a top inclined surface. The force of the wedge block 503 pushing against the U-shaped steel bar and the transverse square timber 5023 achieves the pressure and fixation of the comb plate 501 and the pressure plate 5021. By utilizing the light weight and good distribution effect of the square timber, the pressure applied by the concrete is effectively dispersed and transmitted to the web reinforcement.

[0114] In some embodiments, the web reinforcement 603 used to connect the U-shaped steel bars is fixedly connected to the stiffening frame 60. When the selected web reinforcement 603 is not welded and fixed to the stiffening frame 60 below, the web reinforcement 603 is fixed by welding the surrounding reinforcement around the main chord tube of the stiffening frame 60, so as to achieve a stable connection between the first mold 50 and the stiffening frame 60, ensure the stable setting of the first mold 50, and facilitate the stable distribution and transmission of force on the first mold 50 to the stiffening frame 60.

[0115] In some embodiments, such as Figure 20 As shown, several segments of the first pressing mold 50 are arranged to form unloading vibration holes between adjacent first pressing molds 50.

[0116] This embodiment of a rigid frame arch bridge external concrete formwork system includes a comb-tooth plate 501 that can fit against the web reinforcement 603. A pressure plate 5021 applies flat pressure to the comb-tooth side and comb-back side of the comb-tooth plate 501, closing the gaps between the comb teeth after the comb-tooth plate 501 holds the web reinforcement 603, thus achieving the integrity of the formwork structure and achieving circumferential sealing of the web reinforcement 603. This forms an external pressure flat-pressure formwork structure relative to the bottom plate inner formwork 103, bottom plate side formwork 102, web inner side formwork 202, and web outer side formwork 201. The formwork structure can stably withstand stress. The material is transferred to the stiffening frame 60 and pressed against the top surface of the space to be poured, achieving a stable and smooth seal of the space to be poured. This prevents bulging and leakage of grout at the point where the web reinforcement 603 protrudes. At the same time, the segmented setting of the first pressing mold 50 can quickly match the curve shape of the arch rib, improve the quality of the formed arch rib shape, and increase the flexibility of the setting of the first pressing mold 50. It can effectively avoid the existing structure of the stiffening frame 60, improve the stability of the pressing mold, and flexibly combine to form unloading vibration holes, providing convenience for concrete vibration and ensuring the quality of concrete pouring.

[0117] Example 6

[0118] like Figures 21-22As shown, this embodiment of a rigid frame arch bridge external concrete formwork system, based on embodiment 1, further includes a transverse formwork 70. The transverse formwork 70 includes a transverse outer formwork 701 and a transverse inner formwork 703. The transverse outer formwork 701 includes a transverse bottom formwork 7011, an arch top side outer formwork 7012, an arch foot side outer formwork 7013, and a transverse top formwork 7014. The arch top side outer formwork 7012 includes a first outer formwork 70121 and a second outer formwork 70122 arranged sequentially from bottom to top along the height direction. The first outer formwork 70121, the transverse bottom formwork 7011, and the arch foot side outer formwork 7013 form an L-shaped formwork 702. The L-shaped formwork 702 can be pre-assembled and connected to the rigid frame 60 segment to be hoisted.

[0119] In this embodiment, a rigid frame arch bridge external concrete formwork system is provided. The transverse connection is a rigid frame 60 structure that connects two adjacent arch ribs laterally. Due to the influence of the arch rib arc structure, the transverse connection is an inclined steel pipe truss structure, which leads to difficulties in controlling the installation accuracy of the inclined surface and high risks of high-altitude operation when installing the transverse connection formwork 70 on the arch.

[0120] In this embodiment, the outer transverse formwork 701 adopts a combined wooden formwork structure with the same structural materials as the bottom plate, top plate, and web plate. By forming the L-shaped template 702 of the outer transverse formwork 701, the L-shaped template 702 can close the outer side of the transverse frame within a certain range. Space is reserved outside the L-shaped template 702 for the subsequent template installation, so that the material of the inner transverse formwork 703 can be easily hoisted to the arch for installation, reducing the risk of high-altitude operations, improving the installation accuracy of the transverse formwork 70, and reducing its installation difficulty.

[0121] In some embodiments, the horizontal cross-bracing outer formwork 701 is partially assembled and connected on the ground to form an L-shaped formwork 702. The remaining horizontal cross-bracing formwork 70 materials are hoisted to the arch for installation. After the horizontal cross-bracing frame is hoisted and installed, the L-shaped formwork 702 partially encloses the horizontal cross-bracing frame, providing a relatively safe construction space for the installation of the beam formwork 70. It also facilitates the hoisting of other formwork materials from the gaps in the horizontal cross-bracing outer formwork 701 into the horizontal cross-bracing for use, reducing the installation difficulty of the horizontal cross-bracing formwork 70, improving its installation quality and efficiency, and thus improving the construction quality of the reinforced frame horizontal cross-bracing outer concrete enclosure.

[0122] Example 7

[0123] A construction method for a reinforced concrete formwork system for a steel-concrete composite arch bridge was disclosed. This method was applied to the construction of the reinforced concrete formwork for a steel-concrete composite arch bridge. The total weight of the reinforced concrete was approximately 69,978 tons, 8.5 times the weight of the rigid frame. The method employed a segmented, balanced loading approach. The first ring of concrete, along with the rigid frame, provided support for subsequent loading. Each ring required segmented pouring, with the arch rib longitudinally symmetrically divided into several pouring segments. In this embodiment, the bottom and top rings were each divided into 48 segments with an average chord length of 13.96 m, and the web ring was divided into 56 segments with an average chord length of 11.9 m. The 6m segment boundaries are appropriately adjusted to facilitate the installation of end molds. Each ring is divided into 8 working faces along the arch rib. The load is symmetrically and evenly applied on both sides of the longitudinal direction of the arch rib. The total pouring time of each working face is controlled within the initial setting time of the concrete. According to the number of working faces, 8 sets of precast bottom plate inner mold 103, bottom plate bottom mold 101, web ring mold 20, top plate inner mold 301, and top plate pressing mold 302 are used. When in use, the bottom plate, web plate, and top plate are used in turn through the corresponding template structure. They are installed and poured in sequence. The minimum number of templates is used to match the catenary variable cross-section characteristics of the arch rib.

[0124] This embodiment describes a construction method for a rigid frame arch bridge external concrete formwork system. By preparing multiple sets of formwork systems, each set of formwork systems has its constituent materials adjusted according to the size of the arch rib at the location to be used. This allows for use in accordance with the segmented construction requirements of the arch rib, improving construction efficiency and ensuring the quality of the formed external concrete shape of each construction segment of the arch rib. At the same time, when using each set of formwork systems, the materials of the bottom plate ring formwork 10 and the top plate ring formwork 30 can be reused according to the actual situation, realizing the reuse of the formwork system by ring, segment, and working surface, reducing the preparation cost of the formwork system and improving construction efficiency.

[0125] In this embodiment, for the construction of the base plate ring formwork 10: the base formwork unit 1011 of multiple pre-assembled wooden molds is pre-assembled on the ground and connected to the middle area of ​​the stiffening frame 60 segment to be hoisted. It is connected to the stiffening frame 60 through arch foot limiting components and tie rods, and is hoisted to the use position along with the stiffening frame 60 segment. This achieves coordination between the ground installation of the base plate bottom formwork 101 and the installation on the arch, reduces the number of steps in the arch formwork installation, improves the installation efficiency and quality of the base plate ring formwork 10, and closes the bottom surface of the stiffening frame 60 through the base plate bottom formwork 101, reducing the risk of working on the arch and the psychological burden on the workers, thereby improving the construction quality and efficiency, and providing a construction passage 104 for other construction processes on the arch, reducing the difficulty of high-altitude operations.

[0126] In some embodiments, after the rigid frame 60 is closed, a patching space will be formed at the bottom plate mold 101 position at the segment connection of the rigid frame 60. A custom-made, appropriately sized modular wooden mold is then hoisted to the bottom of the patching space by a cable crane hoisting platform, and then the patching is installed.

[0127] In this embodiment, for the construction of the web ring formwork 20, the outer web formwork 201, which is close to each other between the two arch ribs, is affected by the transverse bracing and X-bracing, while the inner web formwork 202 is affected by the upper chord horizontal bracing. The scattered assembled wooden formwork is adopted, which is assembled into unit parts by bamboo plywood and square timber. During construction, it is assembled layer by layer from bottom to top. Each layer is equipped with a steel back rib and is fixed to the outer web formwork 201 by horizontal tie rod structure 80. The chamfers and widening parts are cut on site.

[0128] In some embodiments, the outer template unit 203 on the arch foot side is hoisted to the arch top side for cutting and assembly, thereby enabling the turnover of the outer template unit 203.

[0129] In this embodiment, for the construction of the first molding 50: the first molding 50 is assembled before the concrete is poured, then disassembled and placed around the perimeter, and molding is carried out when the concrete is poured about 10cm away from the top surface.

[0130] In this embodiment, for the construction of the top plate ring formwork 30: the top plate inner formwork 301 is divided into 6m segments along the longitudinal direction of the bridge. During assembly, sleepers are set in the bottom plate of the box, and the formwork material in the middle of the top plate inner formwork 301 is laid from bottom to top. Compared with the bottom plate inner formwork 103, square timber is used instead of wooden I-beams. The steel wire rope connection area is formed at the top of both ends of the transverse distribution beam of the steel section without laying square timber and bamboo plywood. The lifting tool 304 erected above the top plate is used to connect the four corner points of the segment with steel wire rope. After being lifted to a certain distance from the ground, the distribution beams of the chamfered sections at both ends of the top plate inner formwork 301 are installed. After the installation is completed, it is lifted again, and the platform components are laid under the top plate inner formwork 301 through welding hangers to form the construction platform 305. Then it is lifted to the top plate elevation for fixing, and the formwork of the steel wire rope connection area is filled.

[0131] In some embodiments, the removal sequence of the top plate ring formwork 30 is the reverse of the installation sequence. After being removed inside the box, it is reused in the next pouring section.

[0132] In this embodiment, for the construction of the top plate ring formwork 30: the first outer formwork 70121, the bottom formwork 7011, and the arch foot side outer formwork 70 of the horizontal connecting formwork 70 are pre-assembled on the ground to the stiffening frame 60 segment to be hoisted, forming an L-shaped formwork 702, which is hoisted to the use position along with the stiffening frame 60 segment, reducing the difficulty of installing the horizontal connecting formwork 70.

[0133] In this embodiment, for concrete pouring construction: the grout inlet holes of the bottom plate ring formwork 10 and the web plate ring formwork 20 are set on the corresponding inner formwork, and the grout inlet hole of the top plate ring formwork 30 is set on the top plate pressing mold 302. The grout inlet hole avoids the rods and node plates. The preferred size of the grout inlet hole is 0.4*0.4㎡. The steel bars in the hole are cut off first and restored after the pouring is completed to facilitate the concrete pouring into the formwork.

[0134] In some embodiments, the concrete is vibrated with a high-frequency vibrator, vibrating one hole at a time along the reserved grout inlet holes. To address the vibration challenge at the large node plate in the middle of the web member 604, a small high-frequency vibrator is customized and lowered to the node plate area for vibration, ensuring the overall quality of the outer concrete.

[0135] In some embodiments, the grout inlet hole is sealed by a fixed combination wooden mold, and the grout inlet hole is sealed in time after the pouring is completed by adding a widened back plate and back rib.

[0136] Example 8

[0137] This embodiment of the construction method for a rigid frame arch bridge external concrete formwork system, based on embodiment 7, involves forming several first transverse channels at the bottom position of the corresponding web ring formwork 20 during the bottom slab pouring using pre-embedded pipes, etc. These channels are used to support the web ring formwork 20 during installation by first limiting rods 107 passing through them, thereby improving the installation stability of the web ring formwork 20 and enabling it to cover a certain distance of the bottom slab ring concrete. This enhances the fusion between the bottom slab ring concrete and the web ring concrete, improves the overall integrity of the external concrete, and enhances the overall appearance quality of the external concrete.

[0138] In some embodiments, such as Figure 5 As shown, during the casting of the web, several second transverse channels 206 are formed by pre-embedded pipes at the bottom position of the corresponding top ring formwork design and installation. When the top ring formwork 30 is installed, the second limiting rods 207 passing through the second transverse channels 206 support the top ring formwork 30, thereby improving the installation stability of the top ring formwork 30 and enabling the top ring formwork 30 to cover a certain distance of the web ring concrete, thereby improving the degree of fusion between the top ring concrete and the web ring concrete, improving the integrity of the outer concrete, and improving the overall appearance quality of the outer concrete.

[0139] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A reinforced concrete formwork system for a rigid frame arch bridge, characterized in that, Including bottom plate ring template (10), web plate ring template (20) and top plate ring template (30): The bottom plate ring formwork (10) includes a bottom plate bottom formwork (101), a bottom plate side formwork (102), a bottom plate inner formwork (103), a first end formwork (40), and a first pressing formwork (50); the bottom plate bottom formwork (101) forms a construction channel (104) on both sides of the arch rib; the bottom plate side formwork (102) includes a steel formwork that matches the shape of the space to be poured; the bottom plate inner formwork (103) is connected to the bottom plate side formwork (102) by tie rods; the bottom plate ring formwork (10) is connected by tie rods. The structure (80) is connected to the stiffening frame (60). The bottom of the steel formwork is fixedly connected through the vertical tie rod structure (80) through the transverse distribution beam of the bottom formwork (101) of the bottom plate. The bottom sides of the steel formwork located at the upper and lower reaches of the arch rib are connected by the horizontal tie rod structure (80). The steel formwork is welded to the upper surface of the lower chord pipe (601) along the tangent direction of the lower chord pipe (601) through the inclined tie rod structure (80) extending from the chamfer section of the arch rib into the bottom plate casting space. The web ring template (20) includes an outer web template (201), an inner web template (202), a second end template, and a second pressing template. The outer web template (201) includes several outer template units (203) that match the height of the web to be poured in the arch section. The several outer template units (203) are spliced ​​along the longitudinal direction of the arch rib to match the arch rib line. The inner web template (202) includes a loosely assembled template. The outer web template (201) and the inner web template (202) are connected by tie rods. The second pressing template is used interchangeably with the first pressing template (50). The outer template units (203) and the second end template are both made of fixed-shape combined wooden molds. The outer template unit (203) includes a first type of template (204) formed by cutting the top edge of the rectangular template unit according to the arch rib line, and a second type of template (205) formed by cutting the top edge of the rectangular template unit and the side edge of the arch top. The first type of template (204) and the second type of template (205) are alternately set along the longitudinal direction of the arch rib. The top plate ring template (30) includes a top plate inner mold (301), a top plate pressing mold (302), a top plate side mold (303), and a third end mold; the top plate inner mold (301) and the bottom plate inner mold (103) are used interchangeably; the top plate side mold (303) and the bottom plate side mold (102) are used interchangeably; the third end mold and the first end mold (40) are used interchangeably; the top plate ring template (30) is connected to the stiffening frame (60) through a tie rod structure (80).

2. The reinforced concrete formwork system for a rigid frame arch bridge as described in claim 1, characterized in that, The bottom mold (101) of the base plate is fixed to the lower chord tube (601) of the rigid frame (60) by a number of U-shaped tie rods (105). A limiting block (106) is provided between the bottom mold (101) and the lower chord tube (601) corresponding to the U-shaped tie rods (105). The limiting block (106) is provided with a steel bar (1061) through it along the axial direction of the lower chord tube (601) and welded to the lower chord tube (601).

3. The reinforced concrete formwork system for a rigid frame arch bridge as described in claim 1, characterized in that, The bottom formwork (101) includes several bottom formwork units (1011) spliced ​​together along the longitudinal direction of the arch rib. A steel longitudinal beam (1012) is set at the center of the bottom longitudinal direction of the bottom formwork unit (1011). The steel longitudinal beam (1012) is connected to the horizontal connecting rod (602) of the stiffening frame (60) through a tie rod structure (80). Adjacent bottom formwork units (1011) are connected by embedded longitudinal connecting steel (1013).

4. The reinforced concrete formwork system for a rigid frame arch bridge as described in claim 1, characterized in that, The first end mold (40) includes a steel end mold (401) and a wooden end mold (402). The steel end mold (401) is held in place by the main chord tube of the stiffening frame (60). The wooden end mold (402) is flush with the steel end mold (401). The first end mold (40) is fitted with steel back ribs (403) on the top and bottom surfaces of the main chord tube respectively. The steel end mold (401) is connected to the outer wall of the main chord tube by a tie rod structure (80) passing through the steel back rib (403). The wooden end mold (402) is connected to the web member (604) of the stiffening frame (60) by the tie rod structure (80).

5. The reinforced concrete formwork system for a rigid frame arch bridge as described in claim 1, characterized in that, The first mold (50) includes a comb plate (501), a pressure plate component (502), a wedge (503) and a limiting component (504). The comb plate (501) is held in place by the web reinforcement (603). The pressure plate component (502) is fitted to the top surface of the comb plate (501). The limiting component (504) is welded to the web reinforcement (603) which is fixedly connected to the stiffening frame (60). The wedge (503) is wedged between the limiting component (504) and the pressure plate component (502). A plurality of the first mold (50) segments are arranged to form unloading vibration holes between adjacent first molds (50).

6. The reinforced concrete formwork system for a rigid frame arch bridge as described in claim 1, characterized in that, It also includes a horizontal connecting template (70), which includes a horizontal connecting outer template (701) and a horizontal connecting inner template (703). The horizontal connecting outer template (701) includes a horizontal connecting bottom template (7011), an arch top side outer template (7012), an arch foot side outer template (7013), and a horizontal connecting top template (7014). The arch top side outer template (7012) includes a first outer template (70121) and a second outer template (70122) arranged sequentially from bottom to top along the height direction. The first outer template (70121), the horizontal connecting bottom template (7011), and the arch foot side outer template (7013) form an L-shaped template (702). The L-shaped template (702) can be pre-installed and connected to the stiffening frame (60) segment to be hoisted.

7. A construction method for a reinforced frame arch bridge external concrete formwork system, characterized in that, The arch rib is longitudinally symmetrically divided into several pouring sections. The total pouring time of each pouring section is controlled within the initial setting time of the concrete. At least one set of the rigid frame arch bridge external concrete formwork system as described in claim 6 is prepared for each pouring section and is symmetrically installed, poured and rotated along both banks of the longitudinal direction of the arch rib. Each set of formwork system is installed and poured in sequence according to the bottom plate, web plate and top plate.

8. A construction method for a reinforced frame arch bridge external concrete formwork system as described in claim 7, characterized in that, The bottom formwork (101) and / or L-shaped formwork (702) are pre-assembled and connected to the stiffening frame (60) segment to be hoisted. The stiffening frame (60) segment is hoisted to the use position, and then the formwork is inserted at the segment connection. The outer formwork unit (203) is assembled on the ground and then hoisted to the arch for installation. Then the inner formwork (202) of the web plate is assembled and installed. The inner formwork (301) of the top plate is suspended and assembled inside the arch box by the lifting tool (304) erected above the top plate. A construction platform (305) is set at the bottom of the inner formwork (301) of the top plate, and an arch box passage (306) is formed under the construction platform (305).

9. A construction method for a reinforced frame arch bridge external concrete formwork system as described in claim 7, characterized in that, During the pouring of the bottom slab, several first transverse channels are reserved; before the installation of the web ring template (20), a first limiting rod (107) is inserted into the first transverse channel to support the web ring template (20); during the pouring of the web, several second transverse channels (206) are reserved; before the installation of the top slab ring template (30), a second limiting rod (207) is inserted into the second transverse channel (206) to support the top slab ring template (30).

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