A beam bottom formwork for cast-in-place breast wall of caisson wharf

Abstract

A beam bottom formwork for a cast-in-place breast wall of a caisson wharf comprises a bottom formwork main beam arranged on one side of the caisson, a bottom formwork is laid on the bottom formwork main beam, the bottom formwork comprises a bottom steel plate fixed on the bottom formwork main beam, and a top steel plate located on the bottom steel plate, a plurality of gaskets are arranged between the top steel plate and the bottom steel plate to pad the top steel plate to form an arch with a pre-arch. The pre-arch is set to eliminate the deflection influence of the bottom formwork main beam with a large span, so that the entire beam bottom formwork is less affected by tide and has high durability and reliability.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, in particular to a beam-type bottom formwork for a cast-in-place breast wall of a caisson wharf. Background Art

[0002] In dock construction, gravity docks have been widely used and have a long history of use because they have the dual functions of dock structure and retaining structure. The mainstream of gravity dock structures is block structure or caisson structure, and the present invention is mainly aimed at caisson structure.

[0003] The breast wall is the upper structure of the caisson gravity wharf. The top of the caisson wall and the lower part of the breast wall are generally located within the water level fluctuation zone. The laying of the bottom formwork, steel bar binding, side formwork installation and concrete pouring of the cast-in-place breast wall often require tide-catching operations. The water-facing surface of the breast wall generally protrudes 30 to 50 cm outward from the water-facing wall of the caisson, and the bottom of the breast wall is about 30 cm lower than the top of the caisson. When the breast wall is cast in place, the protruding part needs to be laid with a cast-in-place bottom formwork. The traditional method of the bottom formwork is to embed a row of platform-shaped nut formwork bolts or reserve a row of reserved holes for installing formwork bolts at a certain elevation on the top of the outer side of the front wall of the caisson, with a bolt spacing of 1 to 2 meters. Then use the bolts to install the triangular steel bracket, and lay the bottom formwork distribution beam and bottom plate on the triangular steel bracket. Since the large-span beam will produce deflection under load, it will affect the laying of the bottom formwork.

[0004] Secondly, there will be deviations in the plane position and elevation of the caisson installation. The water-facing surfaces of each caisson are not on the same plane, and the water-facing walls of adjacent caissons will be misaligned, resulting in a gap between the caisson wall and the bottom template, which will change when the surge hits. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a beam-type bottom formwork for a cast-in-place breast wall of a caisson wharf which can eliminate the influence of deflection.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A beam-type bottom formwork for a cast-in-place breast wall of a caisson wharf comprises a bottom formwork main beam arranged on one side of the caisson, a bottom formwork is laid on the bottom formwork main beam, the bottom formwork comprises a bottom steel plate fixed on the bottom formwork main beam, and a top steel plate located on the bottom steel plate, a plurality of gaskets are arranged between the top steel plate and the bottom steel plate to padded the top steel plate to form an arch with a pre-arch degree.

[0008] Furthermore, the gaskets are arranged along the length direction of the bottom mold main beam and are symmetrically arranged relative to the center line of the bottom mold main beam.

[0009] Furthermore, two adjacent gaskets are arranged at equal intervals.

[0010] Furthermore, the length and width of the gasket are equal, and the thickness of the gasket gradually decreases from the middle of the bottom mold main beam in the length direction to both sides.

[0011] Furthermore, the calculated deflection value at the mid-span of the bottom form main beam is equal to the thickness of the gasket located in the middle of the bottom form main beam.

[0012] Furthermore, the thickness of the bottom steel plate and / or the top steel plate is 5 to 8 mm.

[0013] Furthermore, a working platform steel plate is laid on the bottom mold main beam, and the working platform steel plate is located between the bottom mold plate and the bottom mold main beam and extends outside the bottom mold plate.

[0014] Furthermore, the top steel plate is arranged in blocks and is fixed to the bottom steel plate by bolts.

[0015] Furthermore, the top steel plate moves in the length direction of the bottom form main beam before being fixed, and is closely attached to the caisson wall.

[0016] Furthermore, hangers are provided at both ends of the bottom form main beam, and the hangers are suspended by cantilever beams, and the cantilever beams are installed on the top of the adjacent caisson wall or the top of the cast breast wall.

[0017] Beneficial effects of the present invention:

[0018] The bottom formwork includes a bottom steel plate and a top steel plate. A plurality of gaskets are arranged between the top steel plate and the bottom steel plate to raise the top steel plate to form an arch with a pre-arch. The pre-arch is set to eliminate the influence of the deflection of the main beam of the large-span bottom formwork, so that the entire beam-type bottom formwork is less affected by moisture and has high durability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the beam bottom formwork of the cast-in-place breast wall of the caisson wharf of the present invention installed on the caisson;

[0020] Figure 2 for Figure 1 Front view of the center beam bottom formwork;

[0021] Figure 3 for Figure 2 Side view of the midsole template;

[0022] Figure 4 for Figure 3 A partial enlarged view of the

[0023] In the figure, 1 is the main beam of the bottom formwork, 2 is the bottom formwork, 3 is the steel plate of the working platform, 4 is the hanger, 5 is the cantilever beam, 6 is the anchor rod, 7 is the cushion beam, 8 is the front wall of the caisson, 9 is the inner partition wall of the caisson, 10 is the breast wall to be cast, 11 is the bottom steel plate, 12 is the gasket, and 13 is the top steel plate. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] like Figure 1 and Figure 2 The present invention provides a beam-type bottom formwork for a cast-in-place breast wall of a caisson wharf, which is used by manufacturers of cast-in-place breast walls of caisson structure wharfs. The cast-in-place breast wall of a caisson structure wharf is generally a breast wall section set on a caisson. The construction of the cast-in-place breast wall often adopts a skipping construction method of first odd sections and then even sections or first even sections and then odd sections. The cast-in-place bottom formwork adopts a beam-type bottom formwork of a single-span beam integral type, and the beam-type bottom formwork includes a bottom formwork main beam 1 arranged on one side of the caisson, and a bottom formwork 2 is laid on the bottom formwork main beam 1. Because a working platform is required for the operation, a working platform steel plate 3 is also laid on the bottom formwork main beam 1. The working platform steel plate 3 is located between the bottom formwork 2 and the bottom formwork main beam 1, and extends to the outside of the bottom formwork 2. The part extending outside the bottom formwork 2 serves as a working platform. Suspension rods 4 are provided at both ends of the bottom formwork main beam 1, and the suspension rods 4 are suspended by cantilever beams 5. The cantilever beams 5 are installed on the top of the adjacent caisson wall or the top of the cast breast wall.

[0028] like Figures 2 to 4The bottom formwork 2 includes a bottom steel plate 11 fixed on the bottom formwork main beam 1, and a top steel plate 13 located on the bottom steel plate 11. A plurality of gaskets 12 are provided between the top steel plate 13 and the bottom steel plate 11 to padded the top steel plate 13 to form an arch with a pre-arch. The load of the bottom formwork main beam 1 includes the deadweight of the newly poured concrete of the cantilever part of the breast wall, the deadweight of the breast wall front side formwork, the deadweight of the bottom formwork, the deadweight of the bottom formwork main beam and other construction loads. Therefore, the bottom formwork main beam 1 is mainly designed to perform strength and stiffness verification and calculate the deflection value. Since the large-span bottom formwork main beam 1 will deflect under load, the top steel plate 13 of the bottom formwork 2 is padded to form an arch with a pre-arch, which can eliminate the influence of the deflection.

[0029] The bottom formwork 2 is laid on the bottom form main beam 1, and the gaskets 12 are arranged along the length direction of the bottom form main beam 1 and are symmetrically arranged relative to the center line of the bottom form main beam 1. The adjacent gaskets 12 are arranged at equal intervals, and the length and width of the gaskets 12 are equal, and the thickness of the gaskets 12 gradually decreases from the middle of the length direction of the bottom form main beam 1 to both sides, that is, the thickness of the gasket 12 in the middle of the bottom form main beam 1 is the largest, and the thickness of the gaskets 12 on both sides of the bottom form main beam 1 is the smallest. The calculated deflection value at the mid-span (middle) of the bottom form main beam 1 is equal to the thickness of the gasket 12 located in the middle of the bottom form main beam 1, so the influence of the deflection can be offset by the pre-arch formed. In this embodiment, the thickness of the bottom steel plate 11 and / or the top steel plate 13 is 5 to 8 mm.

[0030] The length of the bottom form main beam 1 is the sum of the length of the corresponding caisson and the distance from the adjacent caisson side walls on both sides. In this embodiment, the length of the currently commonly used large caisson is about 19.5m, or even longer, so the bottom form main beam 1 has a larger span and adopts a "321" type reinforced Bailey beam, with a double-row single-layer arrangement and a row spacing of 45cm. Considering the width of the working platform, a three-row single-layer Bailey beam arrangement is adopted. A 1.35m wide stained glass window is used to connect to form a bottom form with a total width of 1.35m, which can meet the operating requirements. According to calculations, the mid-span deflection value of the bottom form main beam 1 is 20mm, so a steel plate with a thickness of 20mm, a length of 500mm, and a width of 100mm is used as a gasket 12 in the middle of the bottom form main beam 1. The gasket 12 is arranged along the width direction of the bottom form main beam 1, thereby raising the top steel plate 13 by 20mm. Then, along the length direction of the bottom form main beam 1, at intervals of 1000mm, steel plates with a length of 500mm, a width of 100mm, and thicknesses of 18mm, 16mm, 14mm, 12mm, 10mm, 8mm, 6mm, 4mm, and 2mm are used as gaskets 12 to raise the top steel plate 13 to form an arch, which meets the deflection values ​​at various locations of the bottom form main beam 1, thereby eliminating the influence of the deflection.

[0031] There will be deviations in the installation plane position and elevation of the caisson. The water-facing surfaces of the caissons are not on the same plane, and the water-facing walls of adjacent caissons will have front and back misalignments. In order to make the bottom template 2 adapt to various sizes of misalignment, always be able to close to the water-facing surface of the caisson, avoid gaps, and cause leakage when pouring concrete, the top steel plate 13 of the bottom template 2 is set in blocks and can move forward and backward along the length direction of the bottom template main beam 1. After the bottom template 2 is installed as a whole, the top movable steel plate 13 is placed against the front wall 8 of the caisson, close to the caisson wall, to prevent excessive gaps, and the top steel plate 13 is fixed to the bottom steel plate 11 by bolts to prevent changes caused by waves.

[0032] like Figure 1 In this embodiment, the suspension rods 4 at both ends of the bottom formwork main beam 1 are screw rods, and the screw rods have an adjustable length of 10 to 20 cm. The ends of the screw rods are fixed by nuts. By adjusting the nuts or screw rods, the elevation of the bottom formwork 2 can be adjusted to adapt to the height of the caisson. An anchor rod 6 is provided at one end of the cantilever beam 5 away from the suspension rod 4. The bottom of the anchor rod 6 is pre-buried in the top of the caisson wall when the caisson is prefabricated. The top of the anchor rod 6 is within the wrapping range of the breast wall 10 to be cast. Therefore, after the breast wall is cast, the top of the anchor rod 6 is wrapped by the cast breast wall. Therefore, no iron parts will be leaked after the breast wall is cast. The front fulcrum of the cantilever beam 5 is arranged on the top of the adjacent front wall 8 of the caisson, and the anchor rod behind the cantilever beam 5 is arranged at the node between the partition wall 9 and the side wall in the caisson. The pad beam 7 is used at the front fulcrum and the rear anchor point to raise the cantilever beam 5 by 10 to 20 cm, thereby dispersing the force on the fulcrum.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] (1) The beam-type bottom formwork adopts an integral type, including the bottom formwork main beam 1, the bottom formwork 2 and the working platform steel plate 3, which can realize the overall installation and removal, is less affected by tides, and is convenient and quick.

[0035] (2) By arranging a plurality of gaskets 12 between the top steel plate 13 and the bottom steel plate 11, the top steel plate 13 is padded to form an arch with a pre-arch, thereby eliminating the deflection effect of the large-span bottom form main beam 1, making the entire beam-type bottom form less affected by moisture and having high durability and reliability.

[0036] (3) The bottom formwork main beam 1 adopts a large-span Bailey beam, which has high strength and can be used in a turnover manner without loss; it has fast progress, saves labor, improves quality, has a high overall cost-effectiveness, and is easy to promote.

[0037] (4) The beam-type bottom mold 1 is suspended by a screw rod, and the bottom mold elevation can be adjusted quickly and accurately. The entire bottom mold system is assembled and disassembled with high efficiency and labor saving.

[0038] (5) Both ends of the bottom formwork main beam 1 are suspended on the cantilever beam 5 through the hanger rod 4. The cantilever beam 5 is installed on the top of the adjacent caisson wall or the top of the adjacent cast breast wall through the anchor rod 6. Therefore, when the caisson is prefabricated, it is not necessary to embed the formwork bolts or formwork holes on the caisson wall. There are no exposed formwork bolts or formwork bolt hole plugging and repairing quality risks in the water level change area on the side of the thin-walled wall of the caisson. The caisson has high durability and reliability, long service life, and long-term social and economic benefits.

[0039] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A beam bottom formwork for a cast-in-place breast wall of a caisson wharf, characterized in that: include: A bottom formwork main beam is arranged on one side of the caisson, a bottom formwork is laid on the bottom formwork main beam, the bottom formwork comprises a bottom steel plate fixed on the bottom formwork main beam, and a top steel plate located on the bottom steel plate, a plurality of gaskets are arranged between the top steel plate and the bottom steel plate to pad the top steel plate to form an arch with a pre-arch degree; The gaskets are arranged along the length direction of the bottom mold main beam and are symmetrically arranged relative to the center line of the bottom mold main beam; two adjacent gaskets are arranged at equal intervals; the length and width of the gaskets are equal, and the thickness of the gaskets gradually decreases from the middle of the length direction of the bottom mold main beam to both sides; the mid-span calculated deflection value of the bottom mold main beam is equal to the thickness of the gasket located in the middle of the bottom mold main beam; Both ends of the bottom formwork main beam are provided with suspension rods, the suspension rods are suspended by cantilever beams, and the cantilever beams are installed on the top of the adjacent caisson wall; An anchor rod is provided at one end of the cantilever beam away from the hanger rod. The bottom of the anchor rod is embedded in the top of the caisson wall when the caisson is prefabricated, and the top of the anchor rod is within the wrapping range of the breast wall to be cast. The front support point of the cantilever beam is arranged on the top of the front wall of the adjacent caisson, and the anchor rod behind the cantilever beam is arranged at the node between the partition wall and the side wall inside the caisson. Pad beams are used at the front support point and the rear anchor point to raise the cantilever beam by 10 to 20 cm.

2. The beam bottom formwork for the cast-in-place breast wall of the caisson wharf according to claim 1 is characterized by: The thickness of the bottom steel plate and / or the top steel plate is 5 to 8 mm.

3. The beam bottom formwork for the cast-in-place breast wall of the caisson wharf according to claim 1 is characterized by: A working platform steel plate is also laid on the bottom formwork main beam. The working platform steel plate is located between the bottom formwork and the bottom formwork main beam and extends outside the bottom formwork.

4. The beam bottom formwork for the cast-in-place breast wall of the caisson wharf according to claim 1 is characterized by: The top steel plate is arranged in blocks and is fixed to the bottom steel plate by bolts.

5. The beam bottom formwork for the cast-in-place breast wall of the caisson wharf according to claim 1 is characterized by: The top steel plate moves in the length direction of the bottom form main beam before being fixed, and is closely attached to the caisson wall.

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