Arch bridge outer concrete bottom plate formwork installation method and bottom plate formwork thereof

Abstract

The present application relates to arch bridge outer package concrete construction technical field, especially in a kind of arch bridge outer package concrete bottom plate formwork installation method and its bottom plate formwork, the installation method includes before stiff skeleton segment hoisting, preparation bottom mould standard unit and bottom mould inlay unit;Pad height setting stiff skeleton segment;Install bottom mould standard unit, form inlay space at the longitudinal both ends of the bottom of stiff skeleton segment, form operation platform at the lateral both sides of stiff skeleton segment;Hoist and transport stiff skeleton segment to construction position and arch base or the connection of previous installed stiff skeleton segment;After arch rib closure, hoist and transport installation bottom mould inlay unit, realize formwork installation linear control by ground installation and arch installation cooperation, speed up construction progress, ensure construction safety.The force that the bottom plate concrete pouring of the bottom mould formwork is applied to bottom mould is effectively transmitted to stiff skeleton, installation stability is good, installation precision is higher, improve the linear quality of the whole arch bridge of forming.

Description

Technical Field

[0001] This invention relates to the field of construction technology for the outer concrete cladding of arch bridges, and in particular to a method for installing the formwork of the outer concrete cladding base plate of an arch bridge and the formwork itself. 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 internal concrete construction is completed, the steel-concrete composite tube serves as the main load-bearing component, with external formwork used for pouring the outer concrete. However, the load-bearing capacity of steel-concrete composite arch structures is limited. For large-span rigid-frame arch bridges, the outer concrete has a high density, making it impossible to load the concrete all at once. Generally, the concrete is poured in three rings: the bottom slab, the web, and the top slab. The first ring of concrete is poured, forming a new load-bearing structure together with the rigid frame, providing support for subsequent construction stages.

[0004] Among them, the installation of the bottom slab formwork is the most difficult in the construction of the concrete enclosure of the rigid frame. When installing the bottom slab formwork, there is no usable installation platform on the steel pipe concrete arch structure. For large-span arches, the span and rise make the conventional formwork support method impractical. If a mobile suspended platform method is used, the suspended platform is hoisted by crane equipment so that the construction workers can install the formwork on the suspended platform. The suspended platform not only has a small working area and high risk of working at height, but also the formwork needs to change with the arch rib line as the arch bridge angle changes. It is difficult to control the line of installation in the air. Moreover, the construction at height is difficult and time-consuming, and the installation accuracy cannot be guaranteed.

[0005] Therefore, there is an urgent need for a technical solution to address the technical problems of the lack of a suitable installation platform for the formwork installation of the bottom slab of existing large-span rigid frame concrete arch bridges, the inability of conventional mobile suspended platform methods to achieve alignment control during the installation of the bottom slab formwork of large-span arch bridges, the high construction difficulty, long construction time, and the inability to guarantee installation accuracy. Summary of the Invention

[0006] The purpose of this invention is to address the technical problems of existing large-span rigid frame concrete arch bridge bottom slab formwork installation lacking a suitable installation platform, and the inability of conventional mobile suspended platform methods to achieve alignment control during installation, resulting in high construction difficulty, long construction time, and unreliable installation accuracy. This invention provides a method for installing the outer concrete bottom slab formwork of an arch bridge and its own bottom slab formwork.

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

[0008] A method for installing the formwork for the concrete base slab of an arch bridge includes: preparing standard formwork units and filler units before hoisting the stiffening frame segments; elevating the stiffening frame segments; installing the standard formwork units to form filler spaces at both longitudinal ends of the bottom of the stiffening frame segments and working platforms on both transverse sides of the stiffening frame segments; hoisting the stiffening frame segments to the construction position and connecting them to the arch seat or a previously installed stiffening frame segment; and hoisting and installing the filler units after the arch ribs are closed.

[0009] This invention discloses a method for installing the formwork of the outer concrete base slab of an arch bridge. For the formwork structure of the outer concrete base slab of a rigid frame, the bottom formwork is installed on the ground before other parts are installed, and then hoisted together with the rigid frame segments. The bottom formwork forms a working platform before the rigid frame segments are hoisted. Compared to existing base slab formwork installation processes, this method, through the coordination of ground installation and arch-mounted installation, results in faster installation speed, reduced risks of high-altitude work, significant time savings, and higher installation accuracy. It also makes it easier to ensure the bottom formwork matches the arch rib alignment, achieving formwork installation alignment control. Furthermore, after the arch rib segments are hoisted into place, the working platform facilitates other construction processes, reducing the overall difficulty of the outer concrete slab construction. Before and after the arch ribs are closed, the bottom formwork seals the bottom of the rigid frame segments, reducing psychological pressure on workers operating on the arch, thus accelerating construction progress and ensuring construction safety.

[0010] As a preferred embodiment of the present invention, the elevation includes: setting support mechanisms at both ends of the rigid frame segment on the ground, and hoisting the rigid frame segment, turning it over, and placing it on the support mechanisms. This provides bottom installation space for the rigid frame segment in the formwork installation on the ground, improves the installation accuracy of the bottom formwork, and facilitates the control of the formwork installation line.

[0011] As a preferred embodiment of the present invention, the installation bottom formwork standard unit includes: a vertical limiting measure set between the bottom formwork standard unit and the lower chord tube; several U-shaped tie rods sleeved on the lower chord tube; the lower ends of the U-shaped tie rods passing through the bottom formwork standard unit; and being anchored with bolts and then welded to the lower chord tube. The vertical limiting measure is used to restrict the relative position of the bottom formwork and the lower chord tube, ensuring that the arch rib lines of the template installation match. The U-shaped tie rods are anchored with bolts and welded together, allowing for precise adjustment of the relative position of the bottom formwork and the lower chord tube before welding, ensuring a better forming line of the bottom plate.

[0012] As a preferred embodiment of the present invention, it further includes: splicing several standard bottom formwork units at the bottom of the stiffening frame segments according to the arch rib profile, with adjacent standard bottom formwork units connected by longitudinally arranged connecting steel sections. This achieves modular preparation and installation of the bottom formwork template, reducing the difficulty of preparation and installation, and improving the efficiency of preparation and installation.

[0013] As a preferred embodiment of the present invention, it further includes: a steel longitudinal beam disposed along the longitudinal center of the bottom of the standard formwork unit, the steel longitudinal beam being connected to the stiffening frame horizontal connecting rod by a tie rod. This improves the installation stability of the standard formwork unit.

[0014] As a preferred embodiment of the present invention, the vertical limiting measure includes: setting a limiting block at the position corresponding to the U-shaped tie rod between the lower chord tube and the standard unit of the bottom formwork; inserting limiting steel bars through the limiting block and welding them to the lower chord tube; and preparing the limiting block using the concrete to be poured. After the bottom slab is formed, the limiting block is located inside the bottom slab concrete, realizing the combination of precast and cast-in-place bottom slab concrete, which has the effect of controlling the bottom slab line shape. The limiting block, through the welding of limiting steel bars, can ensure the stability of the limiting block position, avoiding uncontrollable overturning during the bottom slab concrete pouring process, making the construction structure of the arch bridge's outer concrete structure controllable, thereby improving quality. At the same time, the limiting block and the U-shaped tie rod correspond vertically, stably transmitting the pressure on the bottom slab formwork during the concrete pouring process to the stiffening frame, improving the stability of the bottom slab formwork during the pouring process, and helping to improve the appearance quality of the formed arch rib.

[0015] As a preferred embodiment of the present invention, the installation of the bottom mold patching unit includes: hoisting the bottom mold patching unit to the installation position, and splicing and connecting the bottom mold patching unit with the bottom mold standard unit. This facilitates a smooth transition installation between the bottom mold patching unit and the bottom mold standard unit.

[0016] As a preferred embodiment of the present invention, the bottom mold patching unit is set on the construction platform, the construction platform is lifted to below the installation position, and the alignment is adjusted and the installation is fixed in conjunction with the hoist tool.

[0017] As a preferred embodiment of the present invention, it further includes: before hoisting the rigid frame segment, a template limiting mechanism is provided, the limiting mechanism being used to restrict the sliding of the bottom formwork standard unit along the rigid frame, so as to ensure the stability of the bottom formwork position during hoisting and in the inclined state on the arch.

[0018] A formwork for the outer concrete base slab of an arch bridge includes a bottom mold, an outer mold, an inner mold, and an end mold. The outer mold includes a steel template that matches the shape of the space to be poured. The inner mold and the outer mold are fixed by tie rods. The bottom mold includes a standard bottom mold unit and a bottom mold patch unit.

[0019] This invention provides a concrete base slab formwork for an arch bridge. By using steel formwork to match the side profile of the arch ribs, the side profile is well-matched. Furthermore, the steel formwork is easy to install using a base formwork platform, which improves construction efficiency and reduces the risks of working at heights. At the same time, the base formwork can be installed using the aforementioned base slab formwork installation method, ensuring a high degree of matching between the bottom profile of the arch ribs and the design profile. The base formwork is effectively connected to the rigid frame, effectively transferring the force applied to the base slab concrete during pouring to the rigid frame. This results in good installation stability and high installation accuracy, which is beneficial for further improving the overall profile quality of the formed arch bridge.

[0020] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention regarding the installation method of the outer concrete base slab formwork for arch bridges are as follows:

[0021] 1. By combining ground installation and arch installation, the installation speed is fast, the danger of working at height is reduced, and a lot of construction time can be saved;

[0022] 2. The installation accuracy is high, which makes it easier to ensure that the bottom formwork matches the arch rib line and achieves control of the formwork installation line.

[0023] 3. After the arch rib segment is hoisted into place, the working platform can facilitate the construction of other processes and reduce the overall construction difficulty of the outer concrete.

[0024] 4. Before and after the arch rib is closed, the bottom formwork seals the bottom of the stiffening frame segment, which allows workers to work on the arch without psychological pressure, which helps to speed up the construction progress and ensure construction safety.

[0025] The beneficial effects of the arch bridge external concrete base slab formwork of the present invention are:

[0026] 1. By using steel formwork to match the side profile of the arch ribs, the side profile is well matched;

[0027] 2. Steel formwork is easy to install using the bottom formwork working platform, which can improve construction efficiency and reduce the risks of working at height;

[0028] 3. The bottom formwork is installed using the above-mentioned bottom plate template installation method to ensure a high degree of matching between the bottom surface line of the arch rib and the design line;

[0029] 4. The bottom formwork is effectively connected to the rigid frame, which effectively transfers the force applied to the bottom formwork by the pouring of the bottom slab concrete to the rigid frame. This results in good installation stability and high installation accuracy, further improving the overall linear quality of the formed arch bridge. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating a method for installing the formwork of the outer concrete base slab of an arch bridge according to the present invention.

[0031] Figure 2This is a schematic diagram of the installation process corresponding to step two in Example 1;

[0032] Figure 3 This is a schematic diagram of the installation of the standard bottom mold unit described in Example 1;

[0033] Figure 4 yes Figure 3 A magnified structural diagram of part A in the middle;

[0034] Figure 5 This is a schematic diagram of the structure of the standard unit of the bottom mold described in Example 1;

[0035] Figure 6 This is a schematic diagram of the limiting block in Embodiment 2;

[0036] Figure 7 This is a schematic diagram of the installation structure of the limiting block in Embodiment 2;

[0037] Figure 8 This is a top view structural diagram of the bottom mold template;

[0038] Figure 9 This is a schematic diagram of the hoisting process of the bottom mold patching unit in Example 3. Figure 1 ;

[0039] Figure 10 This is a schematic diagram of the hoisting process of the bottom mold patching unit in Example 3. Figure 2 ;

[0040] Figure 11 This is a schematic diagram of the hoisting process of the bottom mold patching unit in Example 3. Figure 3 ;

[0041] Figure 12 This is a schematic diagram of the structure of a concrete base plate template for an arch bridge according to the present invention.

[0042] icon:

[0043] 1-Strengthened frame segment, 11-Lower chord tube, 12-Horizontal connecting rod, 2-Bottom formwork, 21-Bottom formwork standard unit, 22-Bottom formwork patching unit, 23-Patching space, 24-Working platform, 25-U-shaped tie rod, 26-Connecting steel, 27-Steel longitudinal beam, 28-Steel transverse beam, 3-Supporting mechanism, 4-Limiting block, 41-Limiting reinforcement bar, 5-Construction platform, 6-Lifting hoist tool, 7-Limiting mechanism, 8-Outer formwork, 9-Inner formwork, 10-Space to be poured. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings.

[0045] 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.

[0046] Example 1

[0047] This embodiment uses a currently under-construction, world's largest span stiffened arch bridge as an example. The main bridge is a 600m span, upper-bearing stiffened concrete arch bridge. The arch ring consists of two parallel arch ribs and inter-rib cross bracing. The arch crown is 8m high, and the arch foot is 12m high, featuring a catenary variable cross-section design. The arch ring is constructed using the steel-concrete composite stiffened arch method, and the stiffened arch is assembled using a cable-stayed, inclined-stayed process. The outer concrete is poured using the stiffened arch as support. Compared to existing stiffened arch bridges, the increased span significantly increases the overall construction difficulty and quality control challenges. The alignment control during construction directly affects the overall construction quality and operational safety of the arch bridge. Therefore, quality control at each construction stage is of paramount importance.

[0048] This embodiment of a method for installing the formwork for the outer concrete base slab of an arch bridge specifically includes:

[0049] Step 1: Before the construction of the rigid frame, according to the arch rib line, the rigid frame segment 1 is prefabricated in the rigid frame prefabrication plant. During the prefabrication and transportation process, the rigid frame segment 1 is laid flat with its side as the bottom.

[0050] Step 2: When the bottom formwork 2 needs to be constructed, support mechanisms 3 are set at both ends of the longitudinal direction of the rigid frame segment 1 on the ground. The rigid frame segment 1 is hoisted, turned over, and placed on the support mechanism 3, forming the bottom installation space of the bottom formwork 2 below the rigid frame segment 1.

[0051] Step 3: Install the pre-prepared bottom mold standard unit 21 through the bottom installation space. After the bottom mold standard unit 21 is installed, the interlocking space 23 is formed at both ends of the bottom longitudinal direction of the stiffening frame segment 1, and the working platform 24 is formed on both sides of the transverse direction of the stiffening frame segment 1.

[0052] Step 4: Hoist the stiffened frame segment 1 with the bottom formwork standard unit 21 installed to the construction position and connect it with the arch seat or the previous stiffened frame segment that has been installed.

[0053] Step 5: Repeat the above process until the arch ribs are closed;

[0054] Step 6: Hoist and install the bottom formwork patching unit 22 to complete the construction of the concrete bottom formwork 2 for the rigid frame arch bridge;

[0055] Step 7: Install the outer mold 8, inner mold 9, and end mold to complete the installation of the base plate template.

[0056] Specifically, both the standard bottom formwork unit 21 and the bottom formwork patching unit 22 adopt a standardized combined wooden formwork structure. The standard bottom formwork unit 21 includes bamboo plywood, wooden I-beams, and steel beams 28 arranged sequentially from top to bottom. The steel beams 28 are arranged every 1m along the chord length and are connected by connecting steel beams 26 arranged longitudinally on the steel beams 28. The wooden I-beams are arranged at intervals and are connected to the steel beams 28 by conventional connecting claws. The bottom formwork patching unit 22 has a similar structure to the standard bottom formwork unit 21 and is customized according to the required length. The wooden I-beams of the bottom formwork patching unit 22 are staggered with those of the standard bottom formwork unit 21. After the construction platform 5 is hoisted to the installation position by a cable crane, the bottom formwork patching unit 22 and the standard bottom formwork unit 21 are spliced ​​and connected by the staggered arrangement of the wooden I-beams, relying on the construction platform 5 and the hoist tool 6.

[0057] Preferably, multiple bottom formwork standard units 21 are spliced ​​at the bottom of each stiffened frame segment 1. All the steel beams 28 of the current bottom formwork standard unit 21 and / or the steel beams 28 of two adjacent bottom formwork standard units 21 are connected by longitudinally arranged connecting steel 26. The connecting steel 26 and the wooden I-beam are arranged between the wooden I-beam and are arranged in the same layer as the wooden I-beam, so as to realize the modular preparation and installation of the bottom formwork template, reduce the difficulty of preparation and installation, and improve the preparation and installation efficiency.

[0058] Preferably, the adjacent bottom formwork standard unit 21 is folded instead of curved according to the arch rib line to achieve matching with the arch rib line. By combining the ground installation of the bottom plate formwork part with the arch installation, the bottom plate line control effect is improved.

[0059] Preferably, the length of each steel beam 28 is such that both ends can extend 70-100cm beyond the stiffened frame segment. A working platform 24 is formed by welding guardrail components to the ends of the steel beam 28 and laying panel components on the steel beam 28 extending beyond the stiffened frame segment 1. The panel components preferably include steel planks and anti-slip triangular wood.

[0060] Preferably, each steel beam 28 includes double-channel steel members arranged in opposite directions, which are connected into a whole by welding steel bars / plates, forming a gap between the double-channel steel members that allows the tie rod structure to pass through, providing space for fixing the template.

[0061] Preferably, the support mechanism 3 includes steel components and / or wooden components. In this embodiment, steel components formed by welding steel profiles are preferred as the support mechanism 3, which is supported at both ends below the stiffened frame segment 1, forming a space in the middle area below the stiffened frame segment 1 to meet the installation requirements of the bottom formwork standard unit 21.

[0062] This embodiment describes a method for installing the formwork for the outer concrete base slab of an arch bridge. For the rigid frame outer concrete base slab formwork structure, the bottom formwork is installed on the ground before other parts, and then hoisted together with the rigid frame segment 1. The bottom formwork 2 forms a working platform 24 before the rigid frame segment 1 is hoisted. Compared to existing base slab formwork installation processes, this combination of ground installation and arch-mounted installation results in faster installation speed, reduced risks associated with high-altitude work, and significant time savings. Furthermore, the ground-installed bottom formwork 2 is easier to control, has higher installation accuracy, and more easily ensures the proper alignment of the bottom formwork with the arch. The rib-line matching enables control of the template installation line. At the same time, after the arch rib segment is hoisted into place, the working platform 24 can provide convenience for other construction processes, reduce the overall construction difficulty of the outer concrete, and before and after the arch rib closure, as well as throughout the entire construction cycle of the outer concrete of the arch bridge, the bottom formwork 2 completely seals the bottom of the stiffening frame segment 1. Before the bottom slab is poured, it can make the workers on the arch without psychological pressure, which is conducive to speeding up the construction progress and ensuring construction safety. After the bottom slab is poured, it can continue to provide the working platform 24 for subsequent construction on the arch.

[0063] Example 2

[0064] This embodiment of the method for installing the concrete base plate formwork for an arch bridge further includes, based on embodiment 1, the method for installing the standard base plate unit 21. Specifically, it includes: setting vertical limiting measures on the standard base plate unit 21 corresponding to the lower chord tube 11; attaching several U-shaped tie rods 25 to the lower chord tube 11; the lower ends of the U-shaped tie rods 25 passing through the standard base plate unit 21; adjusting the relative position with the lower chord tube 11 according to the arch rib line; anchoring the tie rods with bolts and then welding them to the lower chord tube 11; and setting a steel longitudinal beam 27 along the longitudinal center of the bottom of the standard base plate unit 21. The steel longitudinal beam 27 is connected to the stiffening frame horizontal connecting rod 12 by vertical tie rods.

[0065] Preferably, the U-shaped tie rod 25 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 25 is set by a combination of bolt anchoring and welding. Before welding, it is beneficial to accurately adjust the relative position of the bottom formwork 2 and the lower chord tube 11 to ensure a better bottom plate forming line. After welding, it can stably maintain the relative positional relationship between the bottom formwork 2 and the stiffening frame, and effectively transfer the pressure applied to the bottom formwork by the concrete pouring to the stiffening frame during the concrete pouring process, so as to improve the structural stability of the bottom formwork during the construction of the outer concrete of the arch bridge, thereby improving the quality of the constructed arch rib.

[0066] Preferably, the setting of the steel longitudinal beam 27 can reduce the deflection deformation in the middle of the bottom formwork 2 and improve the installation stability of the standard unit 21 of the bottom formwork. The vertical tie rod preferably passes through the gap space formed by the double channel steel of the steel crossbeam 28, and is anchored to the steel crossbeam 28 at the bottom end by bolts, and welded to the stiffening frame horizontal connecting rod 12 at the top end, so that the bolt anchoring position applies force to the steel longitudinal beam 27. In the subsequent pouring process, the pressure of the concrete pouring applied to the bottom formwork can be distributed and transmitted to the steel crossbeam 28 through the steel longitudinal beam 27 and directly to the stiffening frame, which is conducive to further improving the structural stability of the bottom formwork 2 in the construction of the outer concrete of the arch bridge, thereby improving the quality of the constructed arch rib.

[0067] Preferably, the vertical limiting measures include: setting a limiting block 4 at the position corresponding to the U-shaped tie rod 25 between the lower chord tube 11 and the standard unit 21 of the bottom mold, the limiting block 4 is used to limit the relative position of the bottom mold 2 and the lower chord tube 11 to ensure that the arch rib line of the template installation matches.

[0068] Specifically, the limiting block 4 includes an arc-shaped top surface to match the outer surface of the lower chord tube 11. The top and bottom surfaces of the limiting block 4 are provided with grooves to form a concrete passage between the limiting block 4 and the bottom mold 2. This ensures that the limiting block 4 is well integrated with the bottom slab concrete during the pouring of the bottom slab concrete, avoiding the formation of cavities, air bubbles, and other quality defects in the bottom slab due to the setting of the limiting block 4, thereby ensuring the overall pouring quality of the bottom slab concrete.

[0069] Specifically, the limiting block 4 is made of concrete of the same grade as the outer concrete of the arch bridge. By combining the prefabrication and cast-in-place of the bottom slab concrete, the control effect of the bottom slab line shape is improved.

[0070] Specifically, when preparing the limiting block 4, a custom mold is used, and a vibrating table is used for compaction. A fixing hole is reserved in the middle, and a limiting steel bar 41 is inserted. The two ends of the limiting steel bar 41 are set in a bent shape. The limiting steel bar 41 is set along the longitudinal direction of the arch rib and welded to the lower chord tube 11 to achieve a fixed connection between the limiting block 4 and the stiffening frame segment 1. This ensures the stability of the position of the limiting block 4 and avoids uncontrollable displacement or tilting of the limiting block 4 during the pouring of the bottom slab concrete. This makes the construction structure of the outer concrete of the arch bridge controllable, thereby improving the quality.

[0071] Specifically, when the limiting block 4 is installed, the U-shaped tie rod 25 and the limiting block 4 are respectively aligned with the steel beam 28 vertically and arranged at intervals of 1m. This ensures that the force applied to the bottom formwork 2 during the pouring of the bottom slab concrete is effectively transferred to the stiffening frame, thereby ensuring the structural stability of the bottom formwork 2 during the construction of the outer concrete and thus ensuring the pouring quality.

[0072] This embodiment describes a method for installing the formwork for the outer concrete base slab of an arch bridge. Standard formwork units 21 are installed on the ground. Each standard formwork unit 21 has high installation accuracy and good stability. Adjacent standard formwork units 21 simulate the rigid frame outer concrete base slab profile by using a folding-bending method based on the arch rib profile, resulting in a high degree of matching between the overall profile of the formwork and the arch bridge design profile. This facilitates the control of the arch bridge profile. Furthermore, the installation and connection structure of the formwork provides an effective transmission path for the force applied to the base slab during concrete pouring, providing a structural foundation for improving the quality of the concrete pouring and profile control.

[0073] Example 3

[0074] This embodiment of the method for installing the concrete base plate formwork of an arch bridge further includes, based on embodiments 1 and 2: after the arch ribs are closed, the bottom formwork patching unit 22 is set on the construction platform 5, the construction platform 5 is lifted to the installation position, and the alignment is adjusted and the installation is fixed in conjunction with the hoist tool 6.

[0075] Preferably, two bottom formwork fitting units 22 are set on the construction platform 5 according to the width of the arch rib, so that the two bottom formwork fitting units 22 can be hoisted and installed at the same time, so that the formwork installation quality of the two parallel arch ribs of the rigid frame arch bridge is the same.

[0076] Specifically, it includes:

[0077] S1. Based on the on-site measurement of the patching space dimensions, prefabricate the bottom mold patching unit 22 according to the patching dimensions;

[0078] S2. Place the two bottom formwork patching units 22 of the arch rib upstream and downstream on the construction platform 5, support them with square timber, and limit them with steel wire rope.

[0079] S3 and construction platform 5 are transported to the bottom of the arch rib and lifted to the position to be installed by the cable crane located on the upstream and downstream sides of the arch rib through the lifting points on both sides.

[0080] S4. Use a 10t hoist tool 6 to connect the lower chord tube 11 of the arch rib to the lifting lug of the construction platform 5 to achieve the suspension of the construction platform 5 below the position to be installed.

[0081] S5. A soft rope ladder is erected between the construction platform 5 and the bottom formwork 2. Workers enter the construction platform 5 to release the cable lifting points, release the limiting steel wire rope of the bottom formwork patching unit 22, and bind the lifting steel wire rope. A 5t hoist tool 6 is used to connect the arch rib web members and the bottom formwork patching unit 22.

[0082] S6. Lift the bottom mold patching unit 22 to the installation position, use the electric hoist tool 6 to raise and lower it, set vertical limiting measures inside the bottom mold patching unit 22, and then splice it with the bottom mold standard unit 21.

[0083] This embodiment describes a method for installing the concrete base slab formwork for an arch bridge. The base slab formwork is installed using a construction platform 5, and the hoist tool 6 is used for raising and lowering to achieve synchronous and stable installation of two base slab formwork units 22. Depending on the actual situation, the base slab formwork can be removed by proceeding in reverse.

[0084] Example 4

[0085] The method for installing the formwork of the outer concrete base plate of an arch bridge in this embodiment is basically the same as that in embodiment 1, except that: the support mechanism 3 of the steel component works with the wooden component to adjust the placement posture of each stiffening frame segment 1, so that the support mechanism 3 supports the stiffening frame segment 1 in the usage posture for the installation of the base formwork.

[0086] This embodiment describes a method for installing the outer concrete base slab formwork of an arch bridge. On the ground, the formwork of the bottom formwork 2 of each stiffening frame segment 1 is matched according to the arch rib line, thereby improving the installation accuracy of the bottom formwork 2. By improving the line quality of the bottom formwork 2 of each stiffening frame segment 1, the overall line quality of the outer concrete base slab is improved, which is beneficial for the control of the arch bridge line.

[0087] Example 5

[0088] This embodiment of the method for installing the concrete base slab formwork of an arch bridge, based on embodiment 1, further includes the step of setting up a formwork limiting mechanism 7 before hoisting the rigid frame segment 1. The limiting mechanism 7 includes a longitudinal limiting mechanism 7 and a transverse limiting mechanism 7, so as to ensure the stability of the position of the base formwork 2 during hoisting and the inclined state on the arch, and to prevent the base slab formwork from sliding down longitudinally along the rigid frame segment 1.

[0089] Preferably, the longitudinal limiting mechanism 7 includes a thrust bracket disposed on the arch foot side of the stiffened skeleton segment 1, the thrust bracket being able to abut against the end of the arch foot side of the bottom mold standard unit 21.

[0090] Specifically, in this embodiment, the thrust bracket is set at the bottom of the arch foot side of the stiffened frame segment 1, and is formed by welding of structural steel. It can push against the channel steel of the structural steel beam on the arch foot side of the bottom formwork standard unit 21 to achieve longitudinal positioning of all bottom formwork standard units 21 on a single stiffened frame segment 1.

[0091] Preferably, the longitudinal limiting mechanism 7 includes a longitudinal oblique limiting rod welded between the bottom mold standard unit 21 and the lower chord tube 11.

[0092] Specifically, in this embodiment, one end of the longitudinal and oblique limiting rod is welded to the end of the steel beam 28 of the standard unit 21 of the bottom formwork, and the other end is welded to the outer surface of the lower chord tube 11. The longitudinal and oblique limiting rod is inclined along the longitudinal direction of the stiffened skeleton segment 1 toward the arch top side, applying a tensile force to the bottom plate formwork from the arch foot side to the arch top side, thereby dispersing the weight of the bottom plate formwork and effectively transferring the force, ensuring the stability of the bottom formwork 2 in the hoisting and arch-tilting state.

[0093] Preferably, the lateral limiting mechanism 7 includes a lateral and oblique limiting rod welded between the lateral end of the bottom mold standard unit 21 and the lower chord tube 11.

[0094] Specifically, in this embodiment, the horizontal and oblique limiting rod is set laterally along the stiffened frame segment 1, with one end welded to the outer surface of the lower chord tube 11 and the other end welded to the end of the steel beam 28 of the bottom formwork standard unit 21, further ensuring the stability of the bottom formwork 2 in the hoisting and arch-tilting state.

[0095] Preferably, both the longitudinal and transverse inclined limiting rods are made of threaded steel.

[0096] Example 6

[0097] An arch bridge external concrete base slab formwork includes a bottom mold 2, an outer mold 8, an inner mold 9, and end molds. The outer mold 8 includes a steel template that matches the shape of the space to be poured 10. The inner mold 9 and the outer mold 8 are fixed by tie rods. The bottom mold 2 includes a bottom mold standard unit 21 and a bottom mold patching unit 22, and is installed and fixed by an arch bridge external concrete base slab formwork installation method as described above.

[0098] This embodiment of an arch bridge external concrete base slab formwork uses steel formwork to match the side profile of the arch ribs, resulting in a good match in side profile. Furthermore, the steel formwork is easily installed using the bottom formwork 2 working platform 24, improving construction efficiency and reducing the risks of working at heights. Simultaneously, the bottom formwork 2 is installed using the aforementioned base slab formwork installation method, and is installed together with the stiffening frame segment 1, prior to other structures. This not only ensures a high degree of matching between the bottom profile of the arch ribs and the design profile, but also achieves an effective connection between the bottom formwork 2 and the stiffening frame. It effectively transfers the force applied to the bottom formwork 2 during the pouring of the base slab concrete to the stiffening frame, resulting in good installation stability and high installation accuracy, improving the overall profile quality of the formed arch bridge. Moreover, it provides a working platform for subsequent structural installations, improving overall construction efficiency.

[0099] The above description is only 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 method for installing formwork for the outer concrete base slab of an arch bridge, characterized in that, include: Before hoisting the rigid frame segment, prepare the bottom formwork standard unit (21) and the bottom formwork patch unit (22). The bottom formwork standard unit (21) includes bamboo plywood, wooden I-beams and steel beams (28) arranged from top to bottom. The steel beams (28) are arranged at intervals along the chord length direction and are connected by connecting steel (26) arranged longitudinally on the steel beams (28). Each steel beam (28) includes double-channel steel components arranged in opposite directions, which are connected into a whole by welding steel bars / plates, forming a gap between the double-channel steel that can pass through the tie rod structure. Elevate the stiffening frame segment (1) to form the bottom installation space of the bottom mold (2) below the stiffening frame segment (1); Install the bottom formwork standard unit (21). According to the arch rib line, splice several bottom formwork standard units (21) at the bottom of the stiffening frame segment (1). Adjacent bottom formwork standard units (21) are folded instead of bent according to the arch rib line to achieve matching with the arch rib line. All the steel beams (28) of the current bottom formwork standard unit (21) and / or the steel beams (28) of two adjacent bottom formwork standard units (21) are connected by longitudinal connecting steel (26). The connecting steel (26) is set between the wooden I-beams and is on the same layer as the wooden I-beams. A steel longitudinal beam (27) is set along the longitudinal center of the bottom of the standard unit (21) of the bottom formwork. The steel longitudinal beam (27) is connected to the stiffening frame horizontal connecting rod (12) by a vertical tie rod. The vertical tie rod passes through the gap space formed by the double channel steel of the steel crossbeam (28). The bottom end is anchored to the steel crossbeam (28) by bolts, and the top end is welded to the stiffening frame horizontal connecting rod (12). An interlocking space (23) is formed at both ends of the bottom longitudinal direction of the stiffening frame segment (1). A working platform (24) is formed on both sides of the transverse direction of the stiffening frame segment (1). Hoist the stiffened frame segment (1) to the construction position and connect it with the arch seat or the previously installed stiffened frame segment (1); After the arch ribs are closed, the bottom formwork patching unit is hoisted and installed (22).

2. The method for installing the formwork for the outer concrete base slab of an arch bridge as described in claim 1, characterized in that, The elevation includes: setting up support mechanisms (3) at both ends of the longitudinal direction of the rigid frame segment (1) on the ground, and hoisting the rigid frame segment (1) over and placing it on the support mechanism (3).

3. The method for installing the formwork for the outer concrete base slab of an arch bridge as described in claim 1, characterized in that, The installation of the bottom mold standard unit (21) includes: setting a vertical limiting measure between the bottom mold standard unit (21) and the lower chord tube (11), and attaching several U-shaped tie rods (25) to the lower chord tube (11). The lower end of the U-shaped tie rods (25) passes through the bottom mold standard unit (21) and is welded to the lower chord tube (11) after being anchored by bolts.

4. The method for installing the formwork for the outer concrete base slab of an arch bridge as described in claim 3, characterized in that, The vertical limiting measures include: setting a limiting block (4) at the position of the U-shaped tie rod (25) between the lower chord tube (11) and the standard unit of the bottom mold (21), inserting a limiting steel bar (41) through the limiting block (4) and welding it to the lower chord tube (11), and using concrete to be poured to prepare the mold for the limiting block (4).

5. A method for installing formwork for the outer concrete base slab of an arch bridge as described in any one of claims 1-4, characterized in that, The installation of the bottom mold patching unit (22) includes: hoisting the bottom mold patching unit (22) to the installation position, and splicing the bottom mold patching unit (22) with the bottom mold standard unit (21).

6. The method for installing the formwork for the outer concrete base slab of an arch bridge as described in claim 5, characterized in that, The bottom mold patching unit (22) is set on the construction platform (5), the construction platform (5) is lifted to the position to be installed, and the alignment is adjusted and the installation is fixed in conjunction with the hoist tool (6).

7. The method for installing the formwork for the outer concrete base slab of an arch bridge as described in claim 1, characterized in that, Also includes: Yu Before hoisting the rigid frame segment (1), a template limiting mechanism (7) is set up. The limiting mechanism (7) is used to restrict the sliding of the bottom mold standard unit (21) along the rigid frame.

8. A formwork for the outer concrete base slab of an arch bridge, characterized in that, The formwork includes a bottom mold (2), an outer mold (8), an inner mold (9), and an end mold. The outer mold (8) includes a steel template that matches the shape of the space to be poured. The inner mold (9) and the outer mold (8) are fixed by tie rods. The bottom mold (2) includes a bottom mold standard unit (21) and a bottom mold patching unit (22). The formwork is installed using the method described in claim 1 for installing an arch bridge outer concrete base plate formwork.

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