Bottom die pedestal for prefabricating plain concrete section of box girder

Abstract

The bottom die pedestal for prefabricating the plain concrete section of the box girder comprises a pedestal body, a rotary bottom die structure, a supporting adjusting structure and a lifting structure, and the rotary bottom die structure is rotationally connected to the pedestal body; the support adjusting structure is arranged in the pedestal body; the lifting structure is arranged between the rotary bottom die structure and the supporting adjusting structure, one end of the lifting structure is connected with the supporting adjusting structure, and the other end is attached to the rotary bottom die structure. The supporting adjusting structure and the lifting structure are configured in the mode that the supporting adjusting structure drives the rotary bottom die structure to rotate relative to the pedestal body by controlling the lifting structure to ascend and descend. The rotary bottom die structure, the support adjusting structure and the lifting structure are arranged, the rotary bottom die structure is rotated to form a set included angle with the pedestal body, and the rotary bottom die is supported at a plain concrete section of a box girder, so that the shear span ratio m of a precast beam after the beam body is tensioned is reduced, and the shear span ratio of the beam body after the beam body is tensioned and arched is optimized.

Description

Technical Field

[0001] This application relates to the field of precast beam bases, and in particular to a bottom formwork platform for precast box girder concrete sections. Background Technology

[0002] Bridge construction involves the extensive production of precast beams. During production, it was found that the beam shape changes after prestressing is applied to precast beams that are initially simply supported and then made continuous, resulting in a certain degree of camber. During construction, it was also found that at the ends of box girders, especially in the non-continuous sections of the side span box girders, vertical and diagonal concentrated cracks extending along the height of the beam and penetrating the bottom slab are commonly found at a distance of 41-7cm from the beam end. The conventional treatment method is to seal the cracks with grout after they appear, but this method cannot effectively prevent this defect. Utility Model Content

[0003] This application provides a bottom formwork platform for precast box girder concrete sections, which can solve the problem of concentrated vertical and oblique cracks in the precast beam production process in related technologies.

[0004] This application provides a bottom formwork platform for a precast box girder concrete section, comprising: a platform body, a rotating bottom formwork structure, a support and adjustment structure, and a lifting structure. The rotating bottom formwork structure is rotatably connected to the platform body; the support and adjustment structure is disposed inside the platform body; the lifting structure is disposed between the rotating bottom formwork structure and the support and adjustment structure, with one end connected to the support and adjustment structure and the other end fitted to the rotating bottom formwork structure; the support and adjustment structure and the lifting structure are configured such that the support and adjustment structure drives the rotating bottom formwork structure to rotate relative to the platform body by controlling the lifting structure to move up and down.

[0005] In one embodiment, the rotating bottom formwork structure has a beam-body mixed-section design area;

[0006] The supporting and adjusting structure is located below the design area of ​​the beam's mixed-use section;

[0007] One end of the lifting structure is connected to the support and adjustment structure, and the other end is fitted to the design area of ​​the beam's plain concrete section.

[0008] In one embodiment, the rotating bottom formwork structure includes: a regular bottom formwork panel and a plain concrete section bottom formwork panel. The regular bottom formwork panel has a through groove, which is located at the corresponding position of the plain concrete section design area of ​​the beam. The plain concrete section bottom formwork panel is rotatably connected to the inside of the through groove through a rotating structure, and the bottom end of the plain concrete section bottom formwork panel is in contact with the lifting structure.

[0009] In one embodiment, the bottom mold platform further includes a limiting structure, which includes limiting beams fixed to both sides of the platform body in the lateral direction, and the limiting beams are arranged along the longitudinal direction of the platform body.

[0010] In one embodiment, when the support adjustment structure lowers by controlling the lifting structure to drive the rotating bottom mold structure to rotate relative to the pedestal body until it connects with the pedestal body, the bottom end of the rotating bottom mold structure is in contact with the top end of the limiting beam.

[0011] In one embodiment, the support adjustment structure includes an adjustment member and a support beam. The lifting structure is fixed to the support beam, and the support beam is disposed on the adjustment member. The adjustment member controls the lifting structure to rise and fall by adjusting the height of the support beam.

[0012] In one embodiment, the support beam has an adjustment hole; the adjustment component includes: a support, two nuts, and a support plate, one end of the support is threaded and passes through the adjustment hole; both nuts are threaded to one end of the support, and the support beam is disposed between the two nuts; the support plate is disposed between the nuts and the support beam; the diameter of the adjustment hole is larger than the diameter of one end of the support, and the adjustment hole is smaller than the outer diameter of the nuts.

[0013] In one embodiment, a pad is provided at the bottom end of the support.

[0014] In one embodiment, the adjusting member includes a hydraulic pump, one end of which is connected to a support beam.

[0015] In one embodiment, the bottom end of the rotating bottom mold structure is provided with a limiting groove, and the bottom end of the limiting groove is recessed towards the side close to the bottom end of the rotating bottom mold structure; the lifting structure includes: a support rod and a roller, the support rod is fixed to the support adjustment structure; the roller is fixed to the support rod and fits against the inside of the limiting groove.

[0016] The beneficial effects of the technical solutions provided in this application include:

[0017] This application provides a bottom formwork platform for a precast box girder concrete section. The platform includes a rotating bottom formwork structure, a support and adjustment structure, and a lifting structure. The rotating bottom formwork structure can be rotated to form a predetermined angle with the platform body, ensuring stable support of the rotating bottom formwork at the concrete section of the box girder. This creates an angle in the concrete bottom slab of the precast beam at the concrete section, thereby reducing the shear span ratio (m) of the precast beam after tensioning. Theoretical analysis optimizes the shear span ratio of the beam after tensioning and arching, optimizes the shear bearing capacity of the beam's inclined section, eliminates vertical cracks in the concrete section, and ensures that its appearance and physical quality meet acceptance requirements. During the production of the continuous precast beam, the support and adjustment structure, lifting structure, and rotating bottom formwork structure allow the rotating bottom formwork structure to be rotated to a smooth connection with the platform body, facilitating the pouring of the continuous precast beam. The rotating bottom formwork structure is supported on the lifting structure and support and adjustment structure, ensuring that bending deformation does not occur during the pouring of the precast beam. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A front view of the overall structure (lifted state) provided for an embodiment of this application;

[0020] Figure 2 A side view of the overall structure (lifted state) provided for an embodiment of this application;

[0021] Figure 3 A side view of the overall structure (descended state) provided for an embodiment of this application.

[0022] In the diagram: 1. Rotating bottom mold structure; 11. Plain mixed section bottom mold panel; 12. Ordinary bottom mold panel; 13. Rotating structure; 2. Limiting structure; 21. Limiting groove; 22. Limiting beam; 3. Support and adjustment structure; 33. Support beam; 32. Support; 34. Nut; 35. Support plate; 36. Pad; 4. Lifting structure; 41. Roller; 42. Support rod; 5. Platform body. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0024] This application provides a bottom formwork platform for precast box girder concrete sections, which can solve the problem of concentrated vertical and oblique cracks in the precast beam production process in related technologies.

[0025] See Figures 1 to 3This application provides a bottom formwork platform for precast box girder concrete sections, comprising: a platform body 5, a rotating bottom formwork structure 1, a support and adjustment structure 3, and a lifting structure 4. The rotating bottom formwork structure 1 is rotatably connected to the platform body 5; the support and adjustment structure 3 is disposed inside the platform body 5; the lifting structure 4 is disposed between the rotating bottom formwork structure 1 and the support and adjustment structure 3, with one end of the lifting structure 4 connected to the support and adjustment structure 3 and the other end fitting against the rotating bottom formwork structure 1; the support and adjustment structure 3 and the lifting structure 4 are configured such that the support and adjustment structure 3 controls the lifting structure 4 to move up and down, thereby driving the rotating bottom formwork structure 1 to rotate relative to the platform body 5.

[0026] In this application, the rotating bottom formwork structure 1, the support and adjustment structure 3, and the lifting structure 4 are configured to rotate the rotating bottom formwork structure 1 to form a set angle with the platform body 5, so that the rotating bottom formwork is stably supported at the plain concrete section of the box girder, and the concrete of the precast beam bottom slab at the plain concrete section forms an angle, thereby ensuring that the shear span ratio m of the precast beam after tensioning is reduced. Through theoretical analysis, the shear span ratio of the beam after tensioning and arching is optimized, the shear bearing capacity of the beam's inclined section is optimized, the occurrence of vertical cracks in the plain concrete section is eliminated, and the appearance quality and physical quality are ensured to meet the acceptance requirements. During the production of the precast beam at the continuous end, the rotating bottom formwork structure 1 can be rotated to smoothly connect with the platform body 5 through the support and adjustment structure 3, the lifting structure 4, and the rotating bottom formwork structure 1, so as to facilitate the pouring of the precast beam at the continuous end. The rotating bottom formwork structure 1 is supported on the lifting structure 4 and the support and adjustment structure 3, ensuring that no bending deformation occurs during the pouring of the precast beam.

[0027] The rotating bottom formwork structure 1 has a beam-body mixed section design area; the support and adjustment structure 3 is located below the beam-body mixed section design area; one end of the lifting structure 4 is connected to the support and adjustment structure 3, and the other end is attached to the beam-body mixed section design area.

[0028] Specifically, the rotating bottom formwork structure 1 includes: a regular bottom formwork panel 12 and a plain concrete section bottom formwork panel 11. The regular bottom formwork panel 12 has a through groove, which is located at the corresponding position of the plain concrete section design area of ​​the beam. The plain concrete section bottom formwork panel 11 is rotatably connected to the inside of the through groove through a rotating structure 13, and the bottom end of the plain concrete section bottom formwork panel 11 is in contact with the lifting structure 4.

[0029] A transverse rotating structure 13 is provided between the base mold panel 11 and the ordinary base mold panel 12 so that the base mold panel 11 can rotate relative to the ordinary base mold panel 12.

[0030] Based on the above embodiments, in this embodiment, the support adjustment structure 3 includes: an adjustment member and a support beam 33. The lifting structure 4 is fixed on the support beam 33. The support beam 33 is disposed on the adjustment member. The adjustment member controls the lifting structure 4 to rise and fall by adjusting the height of the support beam 33.

[0031] In some possible embodiments, an adjustment hole is provided on the support beam 33, and the support beam 33 has a groove-shaped cross-section; the adjustment component includes: a support 32, two nuts 34, and a support plate 35. One end of the support 32 is threaded and passes through the adjustment hole; both nuts 34 are threaded to one end of the support 32, and the support beam 33 is disposed between the two nuts 34; the support plate 35 is disposed between the nuts 34 and the support beam 33.

[0032] In other words, multiple supports 32 are vertically arranged inside the pedestal body 5. Threads are formed on the surface of each support 32 near the end of the rotating bottom mold structure 1, and two nuts 34 are threaded onto this end. Preferably, there are two supports 32, which are used to adjust the vertical movement of the support beam 33. Adjustment holes are formed on the support beam 33, matching the number of adjustment holes to the number of supports 32. When the supports 32 are assembled with the support beam 33, they pass through the adjustment holes. It should be noted that the support beam 33 is positioned between the two nuts 34. By adjusting the position of the two nuts 34 on a support 32, the height of the support beam 33 can be adjusted, allowing the support beam 33 to push or pull down the lifting structure 4, thereby changing the angle of the bottom mold panel 11 of the mixed concrete section. This ensures that the precast beam is cast at a set angle with the surrounding precast beam pedestal surface, i.e., the pedestal body 5 surface. In this embodiment, the set angle is 41°.

[0033] Furthermore, the diameter of the adjustment hole is larger than the diameter of one end of the support 32, and the adjustment hole is smaller than the outer diameter of the nut 34. This design ensures that the support 32 can easily pass through the adjustment hole while maintaining a certain degree of tightness. The size of the adjustment hole is smaller than the outer diameter of the nut 34, which effectively prevents the nut 34 from falling off during adjustment, ensuring the stability and safety of the entire structure.

[0034] In some other possible embodiments, the adjusting component includes a hydraulic pump, one end of which is connected to the support beam 33. When the support 32 is a hydraulic pump, only one end of the hydraulic pump needs to be connected to the support beam 33. When adjusting the angle of the mixed concrete section bottom mold panel 11, one end of the hydraulic pump supports the ground, while the other end lifts the support beam 33, thereby lifting the angle of the mixed concrete section bottom mold panel 11. At the same time, when it is necessary to restore the mixed concrete section bottom mold panel 11, the return stroke of the hydraulic pump ensures that the mixed concrete section bottom mold panel 11 is not subjected to the supporting force of the hydraulic pump, thus completing the rotation of the mixed concrete section bottom mold panel 11. The hydraulic pump is convenient to adjust and readily available.

[0035] The above embodiments are merely various possible implementations of the embodiments of this application, and the embodiments of this application are not limited thereto.

[0036] Furthermore, a pad 36 is provided at the bottom end of the support 32. The pad 36 increases the contact area between the support 32 and the ground, thereby preventing the ground from sinking at the support 32 due to the large force on the support 32, which could lead to the collapse of the adjustable rotating bottom mold structure 1, insufficient angle, or the adjustment of the rotating bottom mold structure 1 failing to meet the requirements.

[0037] Based on the above embodiments, in this embodiment, the bottom mold platform further includes a limiting structure 2. The limiting structure 2 includes limiting beams 22 fixed to both sides of the platform body 5 in the transverse direction, and the limiting beams 22 are arranged longitudinally along the platform body 5. Preferably, two limiting beams 22 are provided to limit the rotation of the bottom mold panel 11 of the mixed section. The limiting beams 22 are fully distributed longitudinally along both sides of the platform body 5.

[0038] When the support adjustment structure 3 lowers by controlling the lifting structure 4 to drive the rotating bottom mold structure 1 to rotate relative to the pedestal body 5 and connect with the pedestal body 5, the bottom end of the rotating bottom mold structure 1 is in contact with the top end of the limiting beam 22.

[0039] Specifically, the rotating bottom formwork structure 1, the support adjustment mechanism, and the lifting structure 4 are configured such that when the rotating bottom formwork structure 1 needs to be fixed at the plain concrete section, the limiting beam 22 is embedded on both sides of the platform body 5, and its projection connects with the platform surface of the platform body 5; the support adjustment structure 3 is set in the platform body 5 below the design area of ​​the plain concrete section of the beam, and the support adjustment structure 3 is adjusted to control the lifting structure 4 to raise and lower the plain concrete section bottom formwork panel 11 until the plain concrete section bottom formwork panel 11 forms a 41° angle with the platform body 5.

[0040] After the precast beam is poured, the adjustment support adjustment structure 3 controls the lifting structure 4 to lower the bottom formwork panel 11 of the mixed concrete section until it connects with the platform body 5 and falls on the limiting beam 22.

[0041] Furthermore, a limiting groove 21 is provided at the bottom end of the rotating bottom mold structure 1, and the bottom end of the limiting groove 21 is recessed towards the side close to the bottom end of the rotating bottom mold structure 1. The lifting structure 4 includes: a support rod 42 and a roller 41, the support rod 42 is fixed to the support adjustment structure 3; the roller 41 is fixed to the support rod 42 and fits inside the limiting groove 21.

[0042] Specifically, a limiting groove 21 is provided at the bottom end of the bottom mold panel 11 of the mixed section. The limiting groove 21 has a groove-shaped cross section, which ensures that the roller 41 can slide stably on the limiting groove 21 due to its own structural action when sliding, and is not prone to deviating from the limiting groove 21, thereby effectively improving the stability and reliability of the entire structure.

[0043] The bottom formwork panel 11 of the concrete section is supported on the lifting structure 4, the support and adjustment structure 3, and the limiting structure 2, ensuring that it will not bend or deform during the pouring of the precast beam. Excessive pouring force will prevent deformation or damage to the rotating bottom formwork structure 1, thus avoiding grout leakage and the absence of a shaped angle at the bottom of the precast beam during concrete pouring.

[0044] When using the above-mentioned bottom mold base:

[0045] First, the pedestal body 5 is prefabricated; then, the limiting beam 22 is embedded on both sides of the pedestal body 5, and its projection connects with the platform surface of the pedestal body 5; the support adjustment structure 3 is set in the pedestal body 5 below the design area of ​​the beam concrete section, and the support adjustment structure 3 is adjusted to control the lifting structure 4 to lift the concrete section bottom formwork panel 11 and rotate it until the concrete section bottom formwork panel 11 forms a 41° angle with the pedestal body 5.

[0046] After the precast beam is poured, the adjustment support adjustment structure 3 controls the lowering of the lifting structure 4, and the bottom formwork panel 11 of the plain concrete section rotates until it connects with the platform of the pedestal body 5 and falls on the limiting beam 22.

[0047] In summary, the bottom formwork platform of this application, equipped with a rotating bottom formwork structure 1, a support and adjustment structure 3, and a lifting structure 4, can rotate the bottom formwork panel 11 of the plain concrete section at a certain angle and stably support it at the plain concrete section of the box girder. This ensures that the bottom formwork panel 11 of the plain concrete section forms a 41° angle with the platform body 5, thereby reducing the shear span ratio m of the precast beam after tensioning, preventing vertical cracks, and ensuring that its appearance and physical quality meet acceptance requirements. During the production of the precast beam at the continuous end, the support and adjustment structure 3, the lifting structure 4, and the rotating structure 13 can quickly and easily rotate the bottom formwork panel 11 of the plain concrete section to smoothly connect with the platform body 5, facilitating the pouring of the precast beam at the continuous end. The rotating bottom formwork structure 1 is supported on the lifting structure 4, the support and adjustment structure 3, and the limiting structure 2, ensuring that no bending deformation occurs during the pouring of the precast beam. Through theoretical analysis, the shear span ratio of the beam after tensioning and arching was optimized, the shear bearing capacity of the beam's inclined section was optimized, and the occurrence of vertical cracks in the plain concrete section was eliminated.

[0048] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0049] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A bottom formwork platform for precast box girder concrete sections, characterized in that, It includes: Pedestal body(5); A rotating bottom mold structure (1) is rotatably connected to the base body (5); A support adjustment structure (3) is provided inside the pedestal body (5); The lifting structure (4) is located between the rotating bottom mold structure (1) and the support adjustment structure (3). One end of the lifting structure (4) is connected to the support adjustment structure (3), and the other end is attached to the rotating bottom mold structure (1). The support adjustment structure (3) and the lifting structure (4) are configured such that the support adjustment structure (3) controls the lifting structure (4) to lift and lower, thereby driving the rotating bottom mold structure (1) to rotate relative to the pedestal body (5).

2. The bottom formwork platform for precast box girder concrete sections as described in claim 1, characterized in that: The rotating bottom formwork structure (1) has a beam-body mixed section design area; The supporting adjustment structure (3) is located below the design area of ​​the beam body mixed section; The lifting structure (4) is connected to the support and adjustment structure (3) at one end and is attached to the design area of ​​the beam body mixed section at the other end.

3. The bottom formwork platform for precast box girder concrete sections as described in claim 2, characterized in that, The rotating bottom mold structure (1) includes: A common bottom formwork panel (12) is provided with a through groove, which is located at the corresponding position of the design area of ​​the beam body plain section; The bottom mold panel (11) of the mixed section is rotatably connected to the inside of the through groove through the rotating structure (13), and the bottom end of the bottom mold panel (11) is attached to the lifting structure (4).

4. The bottom formwork platform for precast box girder concrete sections as described in claim 1, characterized in that: The bottom mold platform also includes a limiting structure (2), which includes limiting beams (22) fixed on both sides of the platform body (5) in the transverse direction. The limiting beams (22) are arranged longitudinally along the platform body (5).

5. The bottom formwork platform for precast box girder concrete sections as described in claim 4, characterized in that: When the support adjustment structure (3) lowers by controlling the lifting structure (4) to drive the rotating bottom mold structure (1) to rotate relative to the pedestal body (5) to connect with the pedestal body (5), the bottom end of the rotating bottom mold structure (1) is in contact with the top end of the limiting beam (22).

6. The bottom formwork platform for precast box girder concrete sections as described in claim 1, characterized in that, The support adjustment structure (3) includes: Adjusting components; The support beam (33) is fixed to the lifting structure (4). The support beam (33) is set on the adjusting member. The adjusting member controls the lifting structure (4) to rise and fall by adjusting the height of the support beam (33).

7. The bottom formwork platform for precast box girder concrete sections as described in claim 6, characterized in that: The support beam (33) is provided with adjustment holes; The adjusting element includes: Support (32), one end of which is provided with a thread and through which the adjustment hole passes; Two nuts (34), both nuts (34) are threaded to one end of the support (32), and the support beam (33) is disposed between the two nuts (34); A support plate (35) is disposed between a nut (34) and a support beam (33); The diameter of the adjustment hole is larger than the diameter of one end of the support (32), and the adjustment hole is smaller than the outer diameter of the nut (34).

8. The bottom formwork platform for precast box girder concrete sections as described in claim 7, characterized in that: A pad (36) is provided at the bottom end of the support (32).

9. The bottom formwork platform for precast box girder concrete sections as described in claim 6, characterized in that: The adjusting component includes a hydraulic pump, one end of which is connected to the support beam (33).

10. The bottom formwork platform for precast box girder concrete sections as described in claim 1, characterized in that: The bottom end of the rotating bottom mold structure (1) is provided with a limiting groove (21), and the bottom end of the limiting groove (21) is recessed towards the side closer to the bottom end of the rotating bottom mold structure (1); The lifting structure (4) includes: Support rod (42), which is fixed to the support adjustment structure (3); Roller (41) is fixed to support rod (42) and fits inside limiting groove (21).

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