A foldable pile shoe foundation for a jack-up platform and an installation method thereof

Abstract

The present invention discloses a foldable pile plate boot foundation for a self-elevating platform and an installation method thereof, which belongs to the field of marine engineering technology, and includes a pile barrel, a pile plate boot assembly, a rack and a hydraulic cylinder. The rack is welded to the outer wall of the pile barrel, and the pile plate boot assembly is arranged below the pile barrel. The pile plate boot assembly includes two first pile plates and two second pile plates. The two first pile plates are arranged relative to each other in an inverted "V" shape, and the upper ends are connected by rotation through an upper connector. The two second pile plates are arranged relative to each other in a "V" shape, and the lower ends are connected by rotation through a lower connector. The lower end of the first pile plate is connected to the upper end of the second pile plate on the same side by rotation, and the four pile plates form a quadrilateral structure with a variable shape. The hydraulic cylinder is arranged inside the quadrilateral structure, and the lower end of its piston rod drives the pile plate boot assembly to expand or contract laterally. The present invention greatly reduces the resistance of the pile plate boot during the process of inserting and pulling piles. After entering a certain depth in the soft soil layer, the pile plate boot assembly expands, increases the support area, and significantly improves its stability.

Description

Technical Field

[0001] The invention belongs to the technical field of marine engineering, and in particular relates to a foldable pile shoe foundation for a self-elevating platform and an installation method thereof. Background Art

[0002] The self-elevating mining platform is a mobile platform with low cost, strong operational flexibility and high safety, and is widely used in marine engineering construction. The self-elevating platform inserts the pile shoe foundation into the seabed to a certain depth by preloading step by step to provide the required bearing capacity for the upper platform. However, during the pile shoe foundation insertion process, it is very likely to pass through the upper hard and lower soft soil layers, which will cause the pile shoe foundation bearing capacity to drop sharply and sink suddenly, causing the self-elevating platform to overturn, resulting in huge engineering accidents and casualties. In addition, after the self-elevating offshore platform is completed, the pile shoe needs to be pulled out of the seabed and recovered. In this process, due to the deadweight of the soil and the adsorption of the soil on the pile shoe, it is difficult to pull out the pile. In order to solve the problems of puncture damage and difficulty in pulling out the pile during the installation of the above-mentioned pile shoe foundation, relevant researchers need to improve the pile shoe.

[0003] The Chinese invention patent with the publication number CN117306509A discloses an active puncture and anti-skid device and method for the bottom of the pile shoe of a self-elevating drilling platform, including a hydraulic jacking puncture mechanism, a pressure detection mechanism and a data acquisition computer. The hydraulic jacking puncture mechanism is distributed on the circumference of the pile shoe. The hydraulic jacking puncture mechanism can actively puncture the formation, so that the bottom of the pile shoe can anchor the pile to prevent the pile shoe from sliding sideways. The hydraulic jacking puncture mechanism is provided with a pressure detection mechanism, which is used to detect the depth of the pile shoe and the stress condition. The pressure detection mechanism is electrically connected to the data acquisition computer, and the data acquisition computer is used to receive and display the information detected by the pressure detection mechanism to control the movement of the hydraulic jacking puncture mechanism based on the detected information. Through the hydraulic jacking puncture mechanism distributed on the circumference of the pile shoe, the formation is actively punctured, so that the bottom of the pile shoe can anchor the pile to prevent the pile shoe from sliding sideways. However, the structural form of the invention does not deviate from the traditional pile shoe foundation form, and cannot solve the problem of difficulty in pulling piles.

[0004] The Chinese invention patent with publication number CN111305200B provides a pile shoe for a self-elevating drilling platform, including a pile shoe, and a central cavity is opened in the middle of the pile shoe. The pile shoe of the self-elevating drilling platform has a central cavity and a side cavity respectively opened in the central part and both sides of the pile shoe, so that the overall mass of the pile shoe is lighter, and the difficulty of the pile shoe in pulling piles is reduced. By arranging a linkage mechanism inside the central cavity and the side cavity, the side rods on both sides of the pile shoe can be retracted or extended by stretching or pressing down the transmission long rod connected to the platform. When retracted, the resistance of the pile shoe when pulling piles can be reduced. This solution cannot solve the problem of continuing to prevent the pile shoe from sinking after the pile shoe enters the soft soil layer below, and the stability is not significantly improved.

[0005] The Chinese invention patent with the publication number CN105780771B proposes a coupled bionic pile shoe for a self-elevating platform, including an upper cone, a lower cone and pile legs, the upper cone is fixed with a plurality of pile legs, the upper cone is egg-shaped, the lower cone is connected with a plurality of spherical table-shaped first shells, the bottom of the upper first shell is the top of the next first shell, and the lowermost first shell is connected with a conical second shell. However, although this scheme can obtain better stability, after the snail bionic shape enters the soil, the resistance of passing through the hard soil layer is relatively large, and the resistance is also relatively large during the pile pulling process.

[0006] The Chinese invention patent with publication number CN114182728B discloses a pile shoe foundation that can consolidate soil and its installation method. By pumping out the water in the pile shoe and reducing the pressure in the bin, the pore water in the surrounding soil flows into the internal water storage bin through the drainage hole under the pressure difference between the inside and outside of the pile shoe, so that the surrounding soil is quickly drained and consolidated, greatly improving the bearing capacity and stability of the pile shoe foundation; when the pile shoe is recovered, high-pressure water can be injected into the water storage bin to form a water film between the pile shoe and the soil, which acts as a lubricant and reduces the resistance when the pile shoe is pulled up. However, it cannot effectively solve the risk of puncture during installation.

[0007] It can be seen that the above-mentioned prior art mainly reduces the installation risk, increases the bearing capacity and anti-overturning ability of the pile shoe by adding other mechanisms or providing additional power sources, or reduces the penetration resistance based on bionics to achieve the purpose of improving the bearing capacity of the pile shoe. In addition, the main treatment method of the prior art for pile pulling is still to use a pile punching nozzle to spray high-pressure gas, water or a mixture of the two when pulling out the pile. This method is complicated and increases the difficulty of manufacturing the pile shoe. There is also an increase in ventilation at the bottom of the pile shoe to reduce the negative pore water pressure in the soil to reduce the adsorption force of the pile shoe, but the adhesion effect between the soil and the pile shoe still exists. The existing pile shoe has a large resistance when inserted or pulled out of the hard soil layer, and the support force and stability are insufficient after entering the soft soil layer, resulting in the problem of sinking. Therefore, it is particularly important to develop a folding pile shoe foundation and its installation method. Summary of the invention

[0008] In view of the deficiencies of the above-mentioned prior art, one purpose of the present invention is to propose a foldable pile shoe foundation for a self-elevating platform, so as to solve the problem that the main treatment method of the prior art for pile pulling is to use a pile punching nozzle to spray high-pressure gas, water or a mixture of the two when pulling out the pile. This method has complex process and is difficult to manufacture the pile shoe. There is also a method of increasing ventilation at the bottom of the pile shoe to reduce the adsorption force of the negative pore water pressure in the soil on the pile shoe, but the adhesion effect between the soil and the pile shoe still exists, the pile shoe has great resistance when inserted into or pulled out of the hard soil layer, and the support and stability are insufficient after entering the soft soil layer, resulting in sinking.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0010] A foldable pile shoe foundation for a self-elevating platform comprises a pile barrel, a pile shoe assembly, a rack and a hydraulic cylinder. The pile barrel is a steel straight cylinder and is arranged vertically. The rack is vertically fixed and welded to the outer wall of the pile barrel, and its toothed surface is located on the side away from the pile barrel.

[0011] The pile shoe assembly is arranged below the pile barrel and is detachably fixedly connected to the lower end of the pile barrel.

[0012] The pile plate shoe assembly includes an upper connector, a lower connector, a first pile plate and a second pile plate. There are two first pile plates, which are arranged opposite to each other in an inverted "V" shape. The upper ends are rotatably connected by two first fixed shafts arranged on the front and rear sides of the upper connector.

[0013] There are also two second pile plates, which are arranged opposite to each other in a "V" shape, and the lower ends are rotatably connected through a second fixed shaft fixedly penetrated in the lower connecting body.

[0014] The lower end of each first pile plate is rotatably connected to the upper end of the second pile plate on the same side through a rotating shaft, and the four pile plates form a quadrilateral structure with a changeable shape.

[0015] The hydraulic cylinder is vertically arranged inside the quadrilateral structure, and the upper connector has a cavity that passes through from top to bottom. The cylinder body of the hydraulic cylinder is fixedly connected to the upper connector in an embedded manner, and the lower end of its piston rod is fixedly connected to the top of the lower connector.

[0016] When in use, the hydraulic cylinder drives the left and right sides of the quadrilateral structure to expand outward or contract inward.

[0017] Furthermore, the first pile plate and the second pile plate are both square metal flat plates, with two left-right symmetrical first shaft sleeves fixed to one end thereof and two left-right symmetrical second shaft sleeves fixed to the other end thereof.

[0018] Furthermore, the first sleeve and the second sleeve are both located on the same side of the pile plate and are fixedly welded to the corresponding ends of the pile plate, and the circumferential outer walls of the first sleeve and the second sleeve are tangent to the outer wall of the pile plate.

[0019] The two first shaft sleeves located at the same end of the pile plate are staggered with the two second shaft sleeves located at the other end of the pile plate.

[0020] Furthermore, the upper connector includes an upper sleeve, a sleeve flange and a flange seat. The upper sleeve is arranged vertically, and the flange seat and the sleeve flange are respectively arranged at the upper and lower ends of the upper sleeve and are fixedly welded to the upper sleeve as a whole.

[0021] Two shaft sleeve seats are symmetrically arranged on the front and rear sides of the middle part of the upper sleeve. The two shaft sleeve seats have longitudinal horizontal blind holes on the side facing away from the upper sleeve. The two blind holes are coaxially arranged. One end of the first fixed shaft is passed through the blind hole of the shaft sleeve seat on the same side and is fixedly connected to the shaft sleeve seat on the same side.

[0022] The flange seat is fixedly connected with the lower end bolts of the pile cylinder, a cylinder flange is fixed on the lower outer wall of the cylinder body, the cylinder body is located inside the upper sleeve, and the cylinder flange is fixedly connected with the sleeve flange bolts.

[0023] Furthermore, the lower connecting body includes a lower sleeve and a piston rod support, the lower sleeve is arranged longitudinally and horizontally, the piston rod support is fixedly welded to the top of the lower sleeve, and the lower end of the piston rod is fixedly connected to the piston rod support.

[0024] The second fixed shaft is passed through the interior of the lower sleeve and is key-connected with the lower sleeve. Both ends of the second fixed shaft pass through the lower sleeve and are rotatably connected with the first sleeve and the second sleeve at the lower end of the second pile plate.

[0025] Furthermore, the piston rod is externally sleeved with a conical bellows, the upper end of the conical bellows is fixedly and sealingly sleeved with the lower end of the cylinder body of the hydraulic cylinder, and the lower end of the conical bellows is fixedly and sealingly sleeved with the piston rod support.

[0026] Furthermore, the length of the first pile plate is the same as the length of the second pile plate, and the four pile plates are connected end to end in sequence to form a diamond structure.

[0027] Furthermore, the length of the first pile plate is greater than that of the second pile plate, and the hydraulic cylinder drives the pile plate shoe assembly to expand outward to form an isosceles triangle structure, and the two second pile plates are in the same horizontal plane.

[0028] Another object of the present invention is to provide an installation method for a foldable pile shoe foundation for a jack-up platform.

[0029] A method for installing a foldable pile shoe foundation for a jack-up platform, using the foldable pile shoe foundation, the installation method comprises the following steps:

[0030] Step 1: Assemble the foldable pile shoe foundation on land and fix and weld the rack to the outer wall of the pile barrel.

[0031] The upper connector is assembled with the two first pile plates using the first fixed shaft, the upper end of the hydraulic cylinder is connected to the lower end of the upper connector, and the upper end of the upper connector is fixedly connected to the lower end of the pile barrel by bolts.

[0032] The lower connector is assembled with the two second pile plates using the second fixed shaft, and the two second pile plates are respectively connected to the two first pile plates through the rotating shafts, and then the piston rod end of the hydraulic cylinder is connected to the upper end of the lower connector.

[0033] Step 2: After the foldable pile sheet boot foundation is assembled, it is transported to the installation waters using a transport ship with lifting equipment, and the hydraulic cylinder is connected to the hydraulic station pipeline on the transport ship. The hydraulic station supplies oil to and returns oil to the hydraulic cylinder.

[0034] Afterwards, the hoisting equipment lifts the foldable pile sheet shoe foundation, puts it vertically into the sea water and lowers it to the seabed surface.

[0035] Step 3: A gear drive device is installed at the end of the mechanical arm on the transport ship. The mechanical arm drives the gear drive device into the sea water and is sleeved on the lower part of the pile barrel. The gear of the gear drive device is meshed with the rack, and the gear is driven to rotate by a hydraulic motor.

[0036] Step 4: The hydraulic cylinder drives the pile shoe assembly to retract inward and maintain this posture. The gear drives the pile barrel downward through the rack. The pile shoe assembly passes through the hard soil layer, enters the soft soil layer and continues to move downward. The lower end of the pile barrel stops moving after penetrating the set depth.

[0037] Afterwards, the pressure cylinder drives the pile sheet shoe assembly to expand outward and maintain the expanded state, and the installation of the foldable pile sheet shoe foundation is completed.

[0038] When the foldable pile sheet shoe foundation needs to be dismantled, the hydraulic cylinder first drives the pile sheet shoe assembly to retract inward, and the pile sheet shoe assembly remains in the retracted state. Thereafter, the lifting equipment of the transport ship pulls the foldable pile sheet shoe foundation upward.

[0039] By adopting the above technical solution, the beneficial technical effect of the present invention is as follows: the pile-sheet shoe assembly of the present invention is a quadrilateral structure with adjustable width, and the pile-sheet shoe assembly shrinks to achieve the purpose of reducing the resistance of inserting and pulling piles. After the pile-sheet shoe assembly expands to the soft soil layer below, the support area increases, so that the pile barrel obtains better support stability in the soft soil layer. When pulling piles, the pile-sheet shoe assembly shrinks to reduce the adhesion and pressure of the overlying soil on the pile shoe, and reduces the resistance of the platform when pulling piles. It is simple to make, low in cost, and reusable. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the principle of a foldable pile shoe foundation for a self-elevating platform according to the present invention.

[0041] Figure 2 Figure 1 A schematic diagram of a portion of the drawing shows a first pile plate.

[0042] Figure 3 It is a schematic diagram of the expansion state of the first implementation mode of the present invention.

[0043] Figure 4 It is a schematic diagram of the contracted state of the first implementation mode of the present invention.

[0044] Figure 5 Figure 1 The schematic diagram of another part shows the combined structure of the upper connector and the pile barrel.

[0045] Figure 6 It is a schematic diagram of the combination of the upper connector, the pile barrel and the first fixed shaft of the present invention.

[0046] Figure 7 The schematic diagram of the structure of the lower connector of the present invention.

[0047] Figure 8 It is a schematic diagram of the contracted state of the second implementation of the present invention.

[0048] Fig. 9 It is a schematic diagram of the expansion state of the second implementation method of the present invention. DETAILED DESCRIPTION

[0049] In order to make the advantages and technical solutions of the present invention more clear and explicit, the present invention is described in detail below in conjunction with specific embodiments.

[0050] Embodiment 1, combination Figures 1 to 7A foldable pile shoe foundation for a jack-up platform comprises a pile barrel 1, a pile shoe assembly 2, a rack 3 and a hydraulic cylinder 4. The pile barrel 1 is a steel straight cylinder and is arranged vertically. The rack 3 is vertically fixed and welded on the outer wall of the pile barrel 1, and its toothed surface is located on the side away from the pile barrel 1. The foldable pile shoe foundation is mainly used for jack-up platforms. Multiple foldable pile shoe foundations are inserted into the seabed to provide support for the jack-up platform.

[0051] The pile plate shoe assembly 2 is arranged below the pile barrel 1 and is detachably fixedly connected to the lower end of the pile barrel 1. Specifically, the pile plate shoe assembly includes an upper connector 5, a lower connector 6, a first pile plate 21 and a second pile plate 22, wherein the first pile plate 21 and the second pile plate 22 are both square metal flat plates, and two left-right symmetrical first shaft sleeves 23 are fixed at one end thereof, and two left-right symmetrical second shaft sleeves 24 are fixed at the other end thereof.

[0052] The first sleeve 23 and the second sleeve 24 are both located on the same side of the pile plate, and are fixedly welded to the corresponding end of the pile plate, and the circumferential outer wall of the first sleeve 23 and the second sleeve 24 is tangent to the outer wall of the pile plate. The two first sleeves 23 at one end of the pile plate and the two second sleeves 24 at the other end of the pile plate are staggered.

[0053] There are two first pile plates 21, which are arranged opposite to each other in an inverted "V" shape, and the upper ends of the two first pile plates 21 are rotatably connected by two first fixed shafts 25 arranged on the front and rear sides of the upper connector. There are also two second pile plates 22, which are arranged opposite to each other in a "V" shape, and the lower ends are rotatably connected by a second fixed shaft 26 fixedly penetrated in the lower connector 6.

[0054] A combination of two first pile plates 21 connected by a first fixed shaft 25 and another combination of two second pile plates 22 connected by a second fixed shaft 26 correspond to each other in the upper and lower directions. The lower end of each first pile plate 21 is rotatably connected to the upper end of the second pile plate 22 on the same side through a rotating shaft 27. The two first pile plates 21 and the two second pile plates 22 are connected to form a quadrilateral structure with a changeable shape.

[0055] The outer wall of the pile shoe assembly 2 of the quadrilateral structure is smooth, and an arc outer wall transition is adopted at the hinge. The lower part of the quadrilateral structure is in the shape of a blade with variable angle, which can effectively reduce the resistance of penetration or extraction during the insertion and extraction process.

[0056] The hydraulic cylinder 4 is vertically arranged on the inner side of the quadrilateral structure. The interior of the upper connector 5 has a cavity that passes through from top to bottom and is communicated with the interior of the pile barrel 1. The cylinder body of the hydraulic cylinder 4 is fixedly connected to the lower end of the upper connector 5 in an embedded manner, and the lower end of its piston rod is fixedly connected to the top of the lower connector 6. The hydraulic cylinder 4 can drive the lower connector 6 to rise or fall relative to the upper connector 5, change the distance between the upper connector 5 and the lower connector 6, and realize the outward expansion or inward contraction of the left and right sides of the pile shoe assembly 2 of the quadrilateral structure.

[0057] Preferably, the length of the first pile plate 21 is the same as that of the second pile plate 22, and the four pile plates are connected end to end in sequence to form a diamond structure. The pile plate shoe assembly 2 maintains a diamond state in a contracted state or an expanded state. The pile plate shoe assembly in the contracted state can easily penetrate the hard soil layer above like a blade, and after reaching a certain depth in the soft soil layer below, the pile plate shoe assembly is horizontally unfolded to present a wide expanded state, thereby increasing the force-bearing area and preventing the pile barrel from sinking.

[0058] Specifically, the upper connector 5 includes an upper sleeve 51, a sleeve flange 52 and a flange seat 53. The upper sleeve 51 is arranged vertically. The flange seat 53 and the sleeve flange 52 are respectively arranged at the upper and lower ends of the upper sleeve, and are fixedly welded to the upper sleeve 51 as a whole. The flange seat 53 is fixedly connected with the lower end bolt of the pile barrel 1. The cylinder flange 41 is fixedly provided on the outer wall of the lower part of the cylinder body of the hydraulic cylinder 4. The cylinder flange 41 is sleeved on the lower part of the cylinder body, and its inner side is fixedly welded to the outer wall of the cylinder body of the cylinder flange 41 as a whole. The cylinder flange is fixedly connected with the sleeve flange bolts. The oil inlet and oil return of the cylinder body are located at the lower side of the cylinder flange 41. Most of the cylinder body is located inside the upper sleeve 51, and the part of the lower end extending out of the upper sleeve 51 is relatively short, which can maximize the expansion or contraction of the pile shoe assembly 2 of the quadrilateral structure.

[0059] In addition, two shaft sleeve seats 54 are symmetrically arranged on the front and rear sides of the middle of the upper sleeve 51. The two shaft sleeve seats 54 are arranged at the same height and are fixedly welded to the outer wall of the upper sleeve 51. The two shaft sleeve seats 54 have a longitudinal horizontal blind hole 541 on the side away from the upper sleeve. The two blind holes 541 are coaxially arranged, and the two first fixed shafts 25 are longitudinally horizontally arranged coaxially. One end of each first fixed shaft 25 is inserted into the blind hole 541 of the shaft sleeve seat 54 on the same side and is fixedly connected to the shaft sleeve seat 54 on the same side.

[0060] During assembly, the shaft sleeves at the upper ends of the two first pile plates 21 are placed correspondingly, and the two first fixed shafts 25 are respectively passed through the shaft sleeves from the front and rear sides and inserted into the blind holes 541 of the shaft sleeve seat 54 on the same side, and then each first fixed shaft 25 is fixedly welded to the shaft sleeve seat 54 on the same side. An end of the first fixed shaft 25 away from the shaft sleeve seat 54 is provided with an axle pin that serves as a limit, and the ends of the second fixed shaft 26 and the rotating shaft 27 are also provided with the same axle pin.

[0061] Specifically, the lower connector 6 includes a lower sleeve 61 and a piston rod support 62 . The lower sleeve 61 is arranged longitudinally and horizontally. The piston rod support 62 is fixedly welded to the top of the lower sleeve 61 . The lower end of the piston rod of the hydraulic cylinder 4 is fixedly connected to the piston rod support 61 .

[0062] The second fixed shaft 26 is inserted into the lower sleeve 61, and its two ends are inserted into the corresponding ends of the lower sleeve 61 respectively. The middle part of the second fixed shaft 25 is key-connected with the lower sleeve 61. The first sleeve 23 and the second sleeve 24 at the lower end of the second pile plate 22 are both rotatably connected with the part of the second fixed shaft 25 located outside the lower sleeve 61. The lower connector 6 and the upper connector 5 are always kept vertically facing each other. The hydraulic cylinder 4 is vertically arranged between the lower connector 6 and the upper connector 5. The top of the cylinder body of the hydraulic cylinder 4 is fixedly welded to the bottom of the cylinder flange 52 as a whole.

[0063] The piston rod of the hydraulic cylinder 4 is sleeved with a conical bellows, the upper end of which is fixedly and sealedly sleeved with the lower end of the cylinder body of the hydraulic cylinder 4, and the lower end of which is fixedly and sealedly sleeved with the piston rod support 62. The conical bellows seals the piston rod of the hydraulic cylinder 4 inside to prevent seawater from corroding the piston rod, and also prevents mud and sand from entering the sealing ring between the cylinder body and the piston rod, causing damage to the sealing ring.

[0064] When in use, the lifting equipment on the transport ship vertically places the foldable pile shoe foundation on the seabed, the piston rod of the hydraulic cylinder 4 extends, causing the pile shoe assembly 2 to retract inward and maintain the retracted state, and the mechanical arm on the transport ship engages with the rack 3 through the gear to drive the pile barrel 1 to move vertically downward, and the pile shoe assembly 2 in the retracted state passes through the hard soil layer on the upper layer and enters the soft soil layer on the lower layer and stops moving after reaching the set depth. The hydraulic cylinder 4 drives the lower connector 6 to move upward, and the pile shoe assembly 2 expands laterally and maintains the expanded state. The bottom area of ​​the pile shoe assembly 2 is increased, and the contact area with the soil is increased, which effectively prevents the pile shoe foundation from sinking in the soft soil, and the supporting effect and stability are significantly improved.

[0065] Embodiment 2, combined Figure 8 and Fig. 9 As shown, a foldable pile shoe foundation for a self-elevating platform has a substantially similar structure to the foldable pile shoe foundation disclosed in Example 1, except that the length of the first pile plate 21 is greater than the length of the second pile plate 22, the hydraulic cylinder 4 drives the pile shoe assembly 2 to expand outward until the two second pile plates 22 are in the same horizontal plane, the piston rod of the hydraulic cylinder 4 stops moving, the pile shoe assembly 2 is an isosceles triangle structure as a whole, and this state is maintained to fix the pile shoe foundation to the seabed.

[0066] Specifically, the pile-sheet shoe assembly in the contracted state passes through the hard soil layer and enters the soft soil layer to a set depth and then stops moving. After that, the hydraulic cylinder 4 drives the lower connector 6 to move upward, driving the pile-sheet shoe assembly to expand horizontally to the left and right. The two second pile plates 22 are in a horizontal state, and the pile-sheet shoe assembly 2 as a whole presents a stable triangular structure, which effectively prevents the pile-sheet shoe foundation from sinking in the soft soil layer. In addition, the pile-sheet shoe assembly 2 has high rigidity and stability, providing stable support for the self-elevating platform.

[0067] Embodiment 3, combined Figures 1 to 9 A method for installing a foldable pile shoe foundation for a jack-up platform, using the foldable pile shoe foundation, the installation method comprises the following steps:

[0068] Step 1: Assemble the foldable pile shoe foundation on land and fix and weld the rack 3 to the outer wall of the pile tube 1.

[0069] The upper connector 5 is assembled with the two first pile plates 21 using the first fixed shaft 25 , and then the upper end of the cylinder body of the hydraulic cylinder 4 is connected to the lower end of the upper connector 5 , and the upper end of the upper connector 5 is fixedly connected with the lower end of the pile barrel 1 by bolts.

[0070] The lower connector 6 is assembled with the two second pile plates 22 using the second fixed shaft 26 . The two second pile plates 22 are connected to the two first pile plates 21 via the rotating shaft 27 . Then, the piston rod end of the hydraulic cylinder 4 is connected to the upper end of the lower connector 6 .

[0071] Step 2: After the foldable pile sheet shoe foundation is assembled, it is transported to the installation waters using a transport ship with lifting equipment, and the hydraulic cylinder 4 is connected to the hydraulic station pipeline on the transport ship, and the hydraulic station supplies oil to and returns oil to the hydraulic cylinder 4.

[0072] Afterwards, the hoisting equipment lifts the foldable pile sheet shoe foundation, puts it vertically into the sea water and lowers it to the seabed surface.

[0073] Step 3: A gear drive device is installed at the end of the mechanical arm on the transport ship. The mechanical arm drives the gear drive device into the sea water and is sleeved on the lower part of the pile tube 1. The gear of the gear drive device is meshed with the rack 3, and the gear is driven to rotate by the hydraulic motor.

[0074] Step 4: The piston rod of the hydraulic cylinder 4 extends downward, driving the pile shoe assembly 2 to retract inward and maintain this posture. The gear drives the pile barrel 1 to move downward through the rack 3. The pile shoe assembly 2 passes through the hard soil layer, enters the soft soil layer and continues to move downward. The lower end of the pile barrel 1 stops moving after penetrating the set depth.

[0075] Afterwards, the piston rod of the hydraulic cylinder 4 contracts upward, driving the pile sheet shoe assembly 2 to expand outward laterally and maintain the expanded state, and the installation of the foldable pile sheet shoe foundation is completed.

[0076] When the foldable pile sheet shoe foundation needs to be dismantled, the hydraulic cylinder 4 first drives the pile sheet shoe assembly 2 to retract inward, and the pile sheet shoe assembly maintains the retracted state. After that, the lifting equipment of the transport ship pulls the foldable pile sheet shoe foundation upward.

[0077] Parts not described in the present invention can be implemented by adopting or drawing on existing technologies.

[0078] Furthermore, the terms “first” and “second” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0079] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0080] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A foldable pile shoe foundation for a jack-up platform, characterized in that: It includes a pile barrel, a pile plate shoe assembly, a rack and a hydraulic cylinder. The pile barrel is a steel straight cylinder and is arranged vertically. The rack is vertically fixed and welded on the outer wall of the pile barrel, and its toothed surface is located on the side away from the pile barrel. The pile shoe assembly is arranged below the pile barrel and is detachably fixedly connected to the lower end of the pile barrel; The pile plate shoe assembly comprises an upper connector, a lower connector, a first pile plate and a second pile plate. There are two first pile plates, which are arranged opposite to each other in an inverted "V" shape, and the upper ends are rotatably connected by two first fixed shafts arranged on the front and rear sides of the upper connector. There are also two second pile plates, which are arranged opposite to each other in a "V" shape, and the lower ends are rotatably connected by a second fixed shaft fixedly provided in the lower connecting body; The lower end of each first pile plate is rotatably connected to the upper end of the second pile plate on the same side through a rotating shaft, and the four pile plates form a quadrilateral structure with a changeable shape; The hydraulic cylinder is vertically arranged inside the quadrilateral structure, and the upper connecting body has a cavity that passes through from top to bottom. The cylinder body of the hydraulic cylinder is fixedly connected to the upper connecting body in an embedded manner, and the lower end of the piston rod is fixedly connected to the top of the lower connecting body. When in use, the hydraulic cylinder drives the left and right sides of the quadrilateral structure to expand outward or contract inward; The first pile plate and the second pile plate are both square metal plates, one end of which is fixed with two left-right symmetrical first shaft sleeves, and the other end of which is fixed with two left-right symmetrical second shaft sleeves; The first sleeve and the second sleeve are both located on the same side of the pile plate where they are located, and are fixedly welded to the corresponding ends of the pile plate where they are located, and the circumferential outer walls of the first sleeve and the second sleeve are tangent to the outer wall of the pile plate; Two first bushings located at the same end of the pile plate are staggered with two second bushings located at the other end of the pile plate; The upper connector includes an upper sleeve, a sleeve flange and a flange seat. The upper sleeve is arranged vertically. The flange seat and the sleeve flange are respectively arranged at the upper and lower ends of the upper sleeve and are fixedly welded with the upper sleeve to form an integral body. Two shaft sleeve seats are symmetrically arranged on the front and rear sides of the middle of the upper sleeve, and the two shaft sleeve seats have a longitudinal horizontal blind hole on one side away from the upper sleeve. The two blind holes are coaxially arranged, and one end of the first fixed shaft is inserted into the blind hole of the shaft sleeve seat on the same side and is fixedly connected to the shaft sleeve seat on the same side; The flange seat is fixedly connected with the lower end bolts of the pile cylinder, and a cylinder flange is fixedly connected with the lower outer wall of the cylinder body, the cylinder body is located inside the upper sleeve, and the cylinder flange is fixedly connected with the sleeve flange bolts; The lower connecting body comprises a lower sleeve and a piston rod support, wherein the lower sleeve is arranged longitudinally and horizontally, the piston rod support is fixedly welded to the top of the lower sleeve, and the lower end of the piston rod is fixedly connected to the piston rod support; The second fixed shaft is inserted into the lower sleeve and connected with the lower sleeve key, and both ends of the second fixed shaft pass through the lower sleeve and are rotatably connected with the first sleeve and the second sleeve at the lower end of the second pile plate; The piston rod is externally sleeved with a conical bellows, the upper end of which is fixedly and sealingly sleeved with the lower end of the cylinder body of the hydraulic cylinder, and the lower end of which is fixedly and sealingly sleeved with the piston rod support; The length of the first pile plate is the same as the length of the second pile plate, and the four pile plates are connected end to end in sequence to form a diamond structure; Or the length of the first pile plate is greater than that of the second pile plate, and the hydraulic cylinder drives the pile plate shoe assembly to expand outward to form an isosceles triangle structure, and the two second pile plates are in the same horizontal plane.

2. A method for installing a foldable pile shoe foundation for a jack-up platform, characterized in that: Using the foldable pile shoe foundation as claimed in claim 1, the installation method comprises the following steps: Step 1: assemble the foldable pile shoe foundation on land and fix and weld the rack to the outer wall of the pile barrel; The upper connecting body and the two first pile plates are assembled together using the first fixed shaft, and then the upper end of the cylinder body of the hydraulic cylinder is connected to the lower end of the upper connecting body, and the upper end of the upper connecting body is fixedly connected with the lower end of the pile barrel by bolts; The lower connector is assembled with the two second pile plates by using the second fixed shaft, and the two second pile plates are respectively connected with the two first pile plates by the rotating shaft, and then the piston rod end of the hydraulic cylinder is connected with the upper end of the lower connector; Step 2: After the foldable pile sheet shoe foundation is assembled, it is transported to the installation waters using a transport ship with lifting equipment, and the hydraulic cylinder is connected to the hydraulic station pipeline on the transport ship, and the hydraulic station supplies oil to and returns oil to the hydraulic cylinder; Afterwards, the hoisting equipment lifts the foldable pile sheet shoe foundation, places it vertically into the seawater and lowers it to the seabed surface; Step 3: A gear drive device is installed at the end of the mechanical arm on the transport ship. The mechanical arm drives the gear drive device into the seawater and is sleeved on the lower part of the pile. The gear of the gear drive device is meshed with the rack, and the gear is driven to rotate by a hydraulic motor; Step 4: The hydraulic cylinder drives the pile shoe assembly to retract inward and maintain this posture. The gear drives the pile barrel to move downward through the rack. The pile shoe assembly passes through the hard soil layer, enters the soft soil layer and continues to move downward. The lower end of the pile barrel stops moving after penetrating the set depth. Afterwards, the hydraulic cylinder drives the pile sheet shoe assembly to expand outward and maintain the expanded state, and the installation of the foldable pile sheet shoe foundation is completed; When the foldable pile sheet shoe foundation needs to be dismantled, the hydraulic cylinder first drives the pile sheet shoe assembly to retract inward, and the pile sheet shoe assembly remains in the retracted state. Thereafter, the lifting equipment of the transport ship pulls the foldable pile sheet shoe foundation upward.

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