A steel-mix combined hanging box bottom plate and steel casing interlayer sealing concrete thickening device
By installing a combination device consisting of a tray, a suspender, and a tensioning jack between the bottom plate of the steel-concrete composite caisson and the steel casing, the problem of insufficient concrete thickness in sealing was solved, the bonding force was improved, construction costs and equipment requirements were reduced, and the seismic performance of the bridge structure was enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ROAD & BRIDGE INT CO LTD
- Filing Date
- 2025-07-16
- Publication Date
- 2026-07-24
AI Technical Summary
In the construction of high-pile bridge piers in water using existing technology, the thickness of the sealing concrete between the bottom plate of the steel caisson and the steel casing is insufficient, resulting in high construction costs, large equipment investment, increased structural weight, and poor seismic resistance.
A combination of pallets, booms, and tension jacks is used. A pallet is placed between the bottom plate of the steel-concrete composite caisson and the steel casing. The side plates of the pallet are lifted by tension jacks to tighten against the bottom plate of the caisson, thereby increasing the thickness of the sealing concrete and improving the gripping force.
Without increasing the thickness of the caisson base plate, the bonding force between the sealing concrete and the steel casing was enhanced, reducing construction costs and equipment requirements, and improving the seismic performance of the structure.
Smart Images
Figure CN224549171U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of bridge construction technology, and relates to the construction of cofferdams using steel-concrete composite caissons, specifically to a device for thickening the concrete sealing between the bottom plate of the steel-concrete composite caisson and the steel casing. Background Technology
[0002] Steel caisson cofferdams are commonly used for the construction of high-pile bridge piers in water. Steel-concrete composite caissons are a frequently used type of steel caisson cofferdam, with a precast concrete base and steel side plates. During construction, the steel caisson is lowered to the design elevation along the steel casing used for pile foundation construction. Leaks are then plugged and water is removed from the caisson, and the water is pumped out to create a dry environment for pier construction. To ensure smooth lowering, holes larger than the diameter of the steel casing are usually pre-drilled in the base. After the caisson reaches the design elevation, sealing concrete is poured into the circumferential joint between the base and the steel casing. This sealing concrete not only blocks water and prevents seepage but also must be thick enough to ensure sufficient bond strength with the steel casing, resisting the buoyancy of the water after pumping out the caisson and the downward force exerted on the caisson by the weight of the pier during concrete pouring. To increase the thickness of the sealing concrete, a common method is to thicken the precast base slab. However, this method has the following drawbacks:
[0003] 1. Increased concrete usage in precast foundation slabs leads to higher construction costs;
[0004] 2. The increased weight of the precast base plate necessitates the use of heavy-duty lifting equipment, which increases the difficulty of caisson installation and equipment investment.
[0005] 3. The increase in the structural self-weight is not conducive to the seismic resistance of bridge structures. Summary of the Invention
[0006] The purpose of this utility model is to address the above-mentioned problems by providing a device for thickening the sealing concrete between the bottom plate of a steel-concrete composite caisson and the steel casing, thereby improving the bonding force between the sealing concrete and the steel casing without increasing the thickness of the bottom plate of the caisson.
[0007] The technical solution of this utility model is as follows:
[0008] A device for thickening concrete to seal the gap between the bottom plate and the steel casing of a steel-concrete composite caisson is characterized by comprising a steel casing, a pallet, a lifting rod, and tension jacks; multiple corbels are circumferentially spaced on the outer wall of the upper end of the steel casing; the pallet is a steel structure, comprising a circular pallet bottom plate, a through hole in the middle of the pallet bottom plate with a diameter not less than the outer diameter of the steel casing, and the outer diameter of the pallet bottom plate is not less than the diameter of a pre-reserved hole on the bottom plate of the steel-concrete composite caisson; a pallet side plate of a certain height is fixedly installed around the outer circumference of the pallet bottom plate; the pallet is fitted onto the steel casing through the through hole in the pallet bottom plate; a tension jack is installed on each corbel of the steel casing; a lifting rod is connected between each tension jack and the pallet bottom plate; and the lower end of each lifting rod is anchored to the bottom of the pallet bottom plate.
[0009] This invention increases the thickness of the sealing concrete by setting a tray of a certain height at the bottom of the circumferential joint between the bottom plate of the steel-concrete composite caisson and the steel casing, thereby ensuring sufficient bonding force between the sealing concrete and the steel casing. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the elevation structure of this utility model;
[0011] Figure 2 This is a schematic diagram of the structure of the tray of this utility model. Detailed Implementation
[0012] like Figure 1 , Figure 2 As shown, this utility model includes a steel casing 1, a pallet 2, a lifting rod 3, and a tensioning jack 4; multiple brackets 5 are equidistantly arranged circumferentially on the outer wall of the upper end of the steel casing 1; the pallet 2 is a steel structure, including a circular pallet bottom plate 21, with a through hole 23 in the middle of the pallet bottom plate 21 that is not smaller than the outer diameter of the steel casing, and the outer diameter of the pallet bottom plate 21 is not smaller than the diameter of the reserved hole on the bottom plate of the steel-concrete composite hoisting box; a pallet side plate 22 of a certain height is fixedly arranged around the outer circumference of the pallet bottom plate 21; the pallet is fitted onto the steel casing 1 through the through hole in the pallet bottom plate; a tensioning jack 4 is arranged on each bracket 5 on the steel casing 1; a lifting rod 3 is connected between each tensioning jack 4 and the pallet bottom plate; and the lower end of each lifting rod 3 is anchored to the bottom of the pallet bottom plate 21.
[0013] In a specific implementation of this utility model, in order to facilitate the sealing of the circumferential seam between the pallet bottom plate 21 and the steel casing 1, the top surface of the inner circumferential edge of the pallet bottom plate can be set as a bevel structure, and the circumferential seam between the bevel and the steel casing can be filled with sealing sandbags 6.
[0014] In a specific implementation of this utility model, in order to ensure the strength of the pallet, multiple stiffening ribs 24 can be welded at equal intervals on the top surface of the pallet bottom plate 21 and the inner wall of the pallet side plate 22.
[0015] like Figure 1 As shown, during the construction of the steel-concrete composite caisson cofferdam, the pallet 2 is first lowered to a position below the design elevation of the bottom surface of the caisson base plate. After the steel-concrete composite caisson is lowered to the design elevation, the pallet is then lifted using tensioning jacks 4, ensuring that the top surface of the pallet side plate is firmly pressed against the bottom surface of the caisson base plate 7. Then, sealing concrete 8 is poured, completely filling the circumferential joint between the pallet and the caisson base plate and the steel casing. Because the pallet side plate has a certain height, the thickness of the sealing concrete 8 is increased without increasing the thickness of the caisson base plate. In specific implementation, the height of the pallet side plate 22 can be set according to the required thickness of the sealing concrete to ensure that the bonding force between the sealing concrete 8 and the steel casing 1 fully meets the requirements of the caisson's buoyancy resistance and anti-slip force.
Claims
1. A device for thickening the concrete seal between the bottom plate of a steel-concrete composite caisson and the steel casing, characterized in that: The system includes a steel casing, a pallet, a lifting rod, and tensioning jacks. Multiple brackets are equidistantly arranged circumferentially on the outer wall of the upper end of the steel casing. The pallet is a steel structure, including a circular pallet base plate with a through hole in the center of the base plate, the outer diameter of which is not less than the diameter of a pre-drilled hole on the base plate of the steel-concrete composite hoisting box. Pallet side plates of a certain height are fixed around the outer edge of the base plate. The pallet is fitted onto the steel casing through the through hole in the base plate. Each bracket on the steel casing is equipped with one tensioning jack, and each tensioning jack is connected to the base plate with a lifting rod. The lower end of each lifting rod is anchored to the bottom of the base plate.
2. The concrete thickening device for sealing the gap between the bottom plate of the steel-concrete composite caisson and the steel casing as described in claim 1, characterized in that: The inner ring edge of the pallet bottom plate has a beveled structure, and a sealing sandbag is installed between the bevel and the circumferential seam of the steel casing.
3. The concrete thickening device for sealing the gap between the bottom plate of the steel-concrete composite caisson and the steel casing as described in claim 1, characterized in that: Multiple stiffening ribs are welded at equal intervals on the top surface of the pallet bottom plate and the inner wall of the pallet side plate.