Double-walled steel caisson turnover and connection structure and construction method

Abstract

This invention discloses a reusable connection method and construction technique for a double-walled steel caisson. The connection method includes a top plate, a pair of rubber pads, a concrete layer, and several suspension rods. The top plate covers the top surface of the bottom section wall. The pair of rubber pads are placed on the top plate, located on the inner and outer sides of the steel caisson wall, respectively. The top section wall rests on the pair of rubber pads. Multiple steel brackets are fixedly installed circumferentially at intervals on both the inner and outer walls of the bottom section wall, closely attached to the top plate. Multiple steel brackets are also fixedly installed circumferentially at intervals on the inner and outer walls of the top section wall, corresponding one-to-one with the steel brackets on the bottom section wall. These corresponding steel brackets are connected as a single unit by suspension rods, thereby connecting the top and bottom sections of the wall. The space between the top plate, the pair of rubber pads, and the bottom of the top section wall is filled with a concrete layer. This invention offers advantages such as convenient, safe, and precise reusability, easy installation and dismantling.

Description

Technical Field

[0001] This invention relates to the field of foundation construction technology. More specifically, this invention relates to a reusable connection structure and construction method for a double-walled steel caisson. Background Technology

[0002] Steel cofferdams, used as water-retaining and formwork structures during pier construction, typically consist of walls, a base plate, and internal supports. In deep-water environments, steel cofferdams often employ a double-wall structure. Double-wall steel cofferdam walls are usually welded together, requiring underwater cutting and dismantling, making reuse difficult. If bolted connections are used, the sheer number of bolts results in extensive underwater dismantling work, and bolt deformation is common under stress, making dismantling difficult and compromising the required precision for subsequent installation. If precision-threaded steel bars are used, the large spacing between these bars increases the risk of leakage, making repairs difficult. To address the challenges of installation and dismantling difficulties and leakage risks associated with the reuse of double-wall steel cofferdams, this application proposes a new reusable connection structure and construction method. Summary of the Invention

[0003] One objective of this invention is to provide a reusable connection structure and construction method for a double-walled steel caisson, which has the advantages of convenient, safe, and precise reusability, installation, and dismantling.

[0004] To address the aforementioned technical problems, this invention provides a reusable connection structure for a double-walled steel gantry. The double-walled steel gantry is divided into upper and lower sections: a top section and a bottom section. The reusable connection structure includes a top plate on the top surface of the bottom section, a pair of rubber pads on the inner and outer sides of the top plate, a concrete layer connecting the top and bottom sections, and several suspension rods. The top plate covers the top surface of the bottom section and extends outwards to both sides. The shape of the rubber pads is identical to that of the steel gantry wall. The pair of rubber pads are located on the top plate. The top section of the wall is located on the inner and outer sides of the steel caisson wall, respectively. The top section rests on a pair of rubber pads. The bottom section has multiple steel brackets fixedly installed circumferentially on its inner and outer side walls, which are closely attached to the top plate. The top section also has multiple steel brackets fixedly installed circumferentially on its inner and outer side walls at the top, which correspond one-to-one with the multiple steel brackets on the bottom section. The corresponding steel brackets are connected as one unit by the hanger rods, thereby connecting the top section and the bottom section. The space between the top plate, the pair of rubber pads and the bottom of the top section is filled with a layer of concrete.

[0005] Preferably, the top plate is provided with a plurality of second baffles at intervals, which are inverted and formed into an inverted V-shaped structure on the top plate, and both ends of the second baffles are closed to prevent them from being filled by the concrete layer.

[0006] Preferably, the top plate and the plurality of second baffles are coated with a release agent layer to reduce the adhesion between the concrete layer and the top plate of the bottom section wall.

[0007] Preferably, the multiple second baffles are arranged at uniform intervals along the same circumference of the top plate or are evenly staggered along the inner and outer circumferences of the top plate.

[0008] Preferably, a plurality of first blocks are fixedly provided at uniform intervals along the circumference on the top plate of the bottom section wall, extending to be in close contact with the top section wall, for bearing horizontal loads.

[0009] Preferably, a steel mesh is provided on the bottom horizontal cross brace of the top section wall, which is located within the concrete layer.

[0010] Preferably, the bottom of the top section wall is provided with a connecting pipe, the height of which is higher than the concrete layer, and the top plate of the bottom section wall is provided with a connecting hole. The connecting pipe extends through the concrete layer to the connecting hole, and is used to connect the inner cavity of the top section wall and the bottom section wall.

[0011] This invention also provides a construction method for the reuse of double-walled steel caissons, comprising the following steps:

[0012] Step 1: The top and bottom wall sections are processed separately at the factory and then transported to the construction site;

[0013] Step 2: Install a top plate on the top surface of the bottom section wall and install rubber pads on the top plate, while welding multiple second stops; in addition, weld and fix multiple steel brackets on the inner and outer walls of the bottom section wall.

[0014] Step 3: Weld steel mesh to the bottom of the top section wall; and weld multiple steel brackets to the corresponding positions at the top of the top section wall.

[0015] Step 4: Hoist the top section wall to the bottom section wall, install the lifting rods between the corresponding steel brackets and apply preload;

[0016] Step 5: Before pouring concrete, apply a release agent to the surface of the top plate of the bottom section wall and multiple second blocks; then pour concrete in the space between the top plate, a pair of rubber pads and the bottom of the top section wall, with the filling height higher than the steel mesh.

[0017] Step 6: Weld the first stop block tightly against the inner side of the top section wall, which is only welded to the top plate of the bottom section wall;

[0018] Step 7: Steel cofferdam hoisting and lowering, pouring bottom sealing concrete, dewatering, foundation construction, and pier construction;

[0019] Step 8: Remove the hangers, lift the top section wall, and transfer the top section wall to the next bottom section wall for reuse;

[0020] Arrangement 9: The top section wall and the bottom section wall are connected by welding;

[0021] Step 10: Hoisting and lowering the steel cofferdam, proceeding with the standard construction process.

[0022] The present invention has at least the following beneficial effects:

[0023] 1. This application divides the wall of the double-walled steel caisson into upper and lower parts, and connects the upper and lower parts of the wall in a relatively convenient way through the connection method of this application, which also makes subsequent dismantling convenient; the dismantling and installation process does not require much underwater work, the workload of installation and dismantling is small, and the efficiency is high.

[0024] 2. The connection method and construction method of this application will not damage the structural form of the double-walled steel caisson cofferdam itself, thereby making the double-walled steel caisson cofferdam more accurate for reuse and meeting the requirements for reuse.

[0025] 3. The connection method and construction method of this application ensure the stability and firmness of the connection through the setting of rubber pads and concrete layers, eliminating the risk of water leakage and providing higher safety.

[0026] 4. The connection form and construction method of this application, through the setting of steel mesh and the application of release agent, facilitates subsequent dismantling and ensures the safety of the dismantling process; in addition, through the setting of multiple first blocks and multiple second blocks, the connection form of this application can withstand horizontal loads and resist horizontal forces, and combined with the setting of multiple hangers, it can withstand vertical loads, ensuring the safety and stability of the overall connection form.

[0027] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the elevation layout of the double-walled steel cofferdam splicing form in an embodiment of this application;

[0029] Figure 2 This is an enlarged view of the connection form of the double-walled steel cofferdam in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the plan layout of the double-walled steel cofferdam splicing form in an embodiment of this application.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Top section wall, 2. Bottom section wall, 3. Hanger rod, 4. Steel bracket, 5. First stop block, 6. Second stop block, 7. Rubber pad, 8. Top plate, 9. Release agent layer, 10. Steel mesh, 11. Concrete layer, 12. Connecting pipe, 13. Connecting hole. Detailed Implementation

[0033] To better understand the purpose, structure, and function of this invention, the invention will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0034] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0035] like Figures 1 to 3 As shown, the first objective technical solution of the present invention is: to provide a reusable connection method for a double-walled steel caisson, wherein the double-walled steel caisson wall is divided into upper and lower parts, namely a top section wall 1 and a bottom section wall 2. The top section wall is used for reuse. The reusable connection method for the double-walled steel caisson includes a top plate 8 set on the top surface of the bottom section wall, a pair of rubber pads 7 set on the inner and outer sides of the top plate, a concrete layer 11 connecting the top section wall 1 and the bottom section wall 2 as a whole, and several suspension rods 3. The top plate covers the top surface of the bottom section wall and extends outward to both sides, serving as the bottom mold for pouring the concrete sandwiched between the top section wall and the bottom section wall. The shape of the pair of rubber pads is... All sections are identical in shape to the steel caisson wall. A pair of rubber pads are placed on the top plate, located on the inner and outer sides of the steel caisson wall, respectively. The top section wall rests on the pair of rubber pads. The bottom section wall has multiple steel brackets 4 fixedly installed circumferentially on its inner and outer wall surfaces, which are closely attached to the top plate. The top section wall also has multiple steel brackets fixedly installed circumferentially on its inner and outer wall surfaces at the top, which correspond one-to-one with the multiple steel brackets on the bottom section wall. The corresponding steel brackets are connected as one unit by a hanger rod, thereby connecting the top section wall and the bottom section wall. The space between the top plate, the pair of rubber pads, and the bottom of the top section wall is filled with a layer of concrete.

[0036] The connection system mainly consists of a top plate 8, a hanger 3, a first stop block 5, a second stop block 6, a rubber pad 7, a release agent layer 9, a steel mesh 10, a concrete layer 11, a connecting pipe 12, and a connecting hole 13.

[0037] The suspension rods are made of precision-rolled threaded steel bars and are intermittently arranged on the inside and outside of the steel caisson wall to connect the top and bottom sections of the wall, and mainly bear vertical loads.

[0038] Multiple first blocks are fixedly installed at even intervals along the circumference of the top plate of the bottom section wall, extending to be in close contact with the top section wall, for bearing horizontal loads. The first blocks are made of structural steel and welded to the top of the bottom section wall of the steel caisson, close to the top section wall, but not welded to it; they primarily bear horizontal loads. The first blocks can also be welded to the inner and outer sides of the top of the bottom section wall, in close contact with the top section wall panel. The first blocks can be made of steel plates welded into a T-shaped structure, primarily for transmitting shear force, serving as the main component resisting horizontal forces; the first blocks are only welded to the top plate of the bottom section wall, not to the top section wall.

[0039] Multiple second baffles are spaced apart on the top plate, forming an inverted V-shape. Both ends of the second baffles are closed to prevent them from being filled with concrete. The second baffles are made of angle steel, are inverted and fastened to the top plate of the bottom section wall, and are firmly welded to the top plate of the bottom section wall. After the interlayer concrete is poured, the second baffles interact with the interlayer concrete to resist horizontal forces.

[0040] The rubber pad is made of expandable water-stopping rubber and is used at the contact point between the top section wall and the bottom section wall to stop water flow.

[0041] The top plate and multiple second baffles are coated with a release agent layer to reduce the adhesion between the concrete layer and the top plate of the bottom section wall. The release agent is located on the top plate of the bottom section wall and the second baffles to reduce the adhesion between the concrete and the top plate of the bottom section wall, facilitating the separation of the top and bottom sections of the wall. The multiple second baffles are evenly spaced along the same circumference of the top plate (as shown in the figure) or evenly staggered along the inner and outer circumferences of the top plate.

[0042] A steel mesh is installed on the bottom horizontal brace of the top section wall, located within the concrete layer. This steel mesh, situated on the bottom horizontal brace of the top section wall and within the concrete, serves to improve the overall integrity of the concrete and prevent localized concrete damage and falling during the lifting and rotation of the top section wall, thus mitigating the risk of falling objects from height.

[0043] The concrete is located at the top of the bottom section wall and the bottom of the top section wall. After the top and bottom sections of the wall are joined, the hangers are installed and pre-tensioned, and the release agent is applied, the concrete is poured to form a suitable amount of interlayer concrete. Its function is twofold: firstly, to increase the rigidity of the bottom of the top section wall at the joint, reducing local deformation of the steel caisson and facilitating secondary assembly and positioning; secondly, to act as a seal, preventing water from outside the cofferdam from entering the interlayer of the steel caisson, and preventing water from inside the interlayer from entering the steel caisson. The purpose of pouring concrete for the joint is to stop water, resist shear, and increase the local rigidity of the structure.

[0044] A connecting pipe is installed at the bottom of the top section wall, its height exceeding that of the concrete layer. A connecting hole is provided on the top plate of the bottom section wall. The connecting pipe extends through the concrete layer and into the connecting hole, connecting the inner cavities of the top and bottom sections of the wall. The connecting pipe is temporarily fixed to the bottom structure of the top section wall and is not welded to the bottom section wall, allowing it to be rotated with the top section wall. The connecting pipe is located at the bottom of the top section wall, installed before concrete pouring, its height exceeding the concrete thickness, and positioned above the connecting hole in the bottom section wall, connecting the inner cavities of the top and bottom sections of the wall.

[0045] The second objective of this invention is to provide a construction method for the reusable use of double-walled steel cofferdams, comprising the following steps:

[0046] Step 1: The top and bottom wall sections are processed separately at the factory and then transported to the construction site;

[0047] Step 2: Install a top plate on the top surface of the bottom section wall and install rubber pads on the top plate, while welding multiple second stops; in addition, weld and fix multiple steel brackets on the inner and outer walls of the bottom section wall.

[0048] Step 3: Weld steel mesh to the bottom of the top section wall; and weld multiple steel brackets to the corresponding positions at the top of the top section wall.

[0049] Step 4: Hoist the top section wall to the bottom section wall, install the hangers between the corresponding steel brackets and apply pre-tightening force; the main purpose of applying pre-tightening force is to ensure that there is always pressure at the joint of the sections at each stage of construction, so as to ensure that the joint of the sections is always in a compressed state and thus achieves the purpose of preventing water leakage.

[0050] Step 5: Before pouring concrete, apply a release agent to the surface of the top plate of the bottom section wall and multiple second blocks; then pour concrete in the space between the top plate, a pair of rubber pads and the bottom of the top section wall, with the filling height higher than the steel mesh.

[0051] Step 6: Weld the first stop block tightly against the inner side of the top section wall, which is only welded to the top plate of the bottom section wall;

[0052] Step 7: Steel cofferdam hoisting and lowering, pouring bottom sealing concrete, dewatering, foundation construction, and pier construction;

[0053] Step 8: After the construction of the foundation and pier body is completed, when dismantling the steel caisson, remove the lifting rods, lift the top section wall, and hoist the top section wall to the next bottom section wall for reuse;

[0054] Arrangement 9: The top section wall and the bottom section wall are connected by welding;

[0055] Step 10: Hoisting and lowering the steel cofferdam, proceeding with the standard construction process.

[0056] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention, and other modifications can be easily implemented by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A double-walled steel gantry for reusable connection structure, characterized in that, The double-walled steel caisson is divided into upper and lower sections: a top section and a bottom section. The reusable connection structure includes a top plate on the top surface of the bottom section, a pair of rubber pads on the inner and outer sides of the top plate, a concrete layer connecting the top and bottom sections, and several suspension rods. The top plate covers the top surface of the bottom section and extends outwards to both sides. The shape of the rubber pads is identical to that of the steel caisson wall. The rubber pads are located on the top plate, on the inner and outer sides of the steel caisson wall, respectively. The top section wall rests on a pair of rubber pads. The bottom section wall has multiple steel brackets fixedly installed circumferentially on its inner and outer side walls, which are closely attached to the top plate. The top section wall also has multiple steel brackets fixedly installed circumferentially on its inner and outer side walls at the top, which correspond one-to-one with the multiple steel brackets on the bottom section wall. The corresponding steel brackets are connected as a whole by hangers, thereby connecting the top section wall and the bottom section wall. The space between the top plate, the pair of rubber pads and the bottom of the top section wall is filled with a layer of concrete.

2. The double-walled steel caisson turnover connection structure as described in claim 1, characterized in that, Multiple second baffles are spaced apart on the top plate, which are inverted and formed into an inverted V-shaped structure. Both ends of the second baffles are closed to prevent them from being filled by the concrete layer.

3. The double-walled steel caisson reusable connection structure as described in claim 2, characterized in that, The top plate and multiple second baffles are coated with a release agent layer to reduce the adhesion between the concrete layer and the top plate of the bottom section wall.

4. The double-walled steel caisson reusable connection structure as described in claim 2, characterized in that, Multiple second baffles are arranged at uniform intervals along the same circumference of the top plate or are evenly staggered along the inner and outer circumferences of the top plate.

5. The double-walled steel caisson reusable connection structure as described in claim 1, characterized in that, Multiple first blocks are fixedly installed at even intervals along the circumference of the top plate of the bottom section wall, extending to be in close contact with the top section wall, for bearing horizontal loads.

6. The double-walled steel caisson reusable connection structure as described in claim 1, characterized in that, A steel mesh is installed on the bottom horizontal cross brace of the top section wall, which is located inside the concrete layer.

7. The double-walled steel caisson reusable connection structure as described in claim 1, characterized in that, The top section wall has a connecting pipe at its bottom, which is higher than the concrete layer. The bottom section wall has a connecting hole on its top plate. The connecting pipe extends through the concrete layer to the connecting hole, which is used to connect the top section wall with the inner cavity of the bottom section wall.

8. The construction method of the double-walled steel caisson reusable connection structure as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: The top and bottom wall sections are processed separately at the factory and then transported to the construction site; Step 2: Install a top plate on the top surface of the bottom section wall and install rubber pads on the top plate, while welding multiple second stops; in addition, weld and fix multiple steel brackets on the inner and outer walls of the bottom section wall. Step 3: Weld steel mesh to the bottom of the top section wall; and weld multiple steel brackets to the corresponding positions at the top of the top section wall. Step 4: Hoist the top section wall to the bottom section wall, install the lifting rods between the corresponding steel brackets and apply preload; Step 5: Before pouring concrete, apply a release agent to the surface of the top plate of the bottom section wall and multiple second blocks; then pour concrete in the space between the top plate, a pair of rubber pads and the bottom of the top section wall, with the filling height higher than the steel mesh. Step 6: Weld the first stop block tightly against the inner side of the top section wall, which is only welded to the top plate of the bottom section wall; Step 7: Steel cofferdam hoisting and lowering, pouring bottom sealing concrete, dewatering, foundation construction, and pier construction; Step 8: Remove the hangers, lift the top section wall, and transfer the top section wall to the next bottom section wall for reuse; Arrangement 9: The top section wall and the bottom section wall are connected by welding; Step 10: Hoisting and lowering the steel cofferdam, proceeding with the standard construction process.

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