Suction barrel sinking method and structure

Abstract

The invention discloses a suction cylinder sinking structure which comprises a suction cylinder, a top plate arranged at one end of the suction cylinder, a vibration device in lap joint with the top plate, a lifting appliance and a measuring instrument, the suction cylinder and the vibration device are lifted to the water bottom through the lifting appliance, the vibration device vibrates, and the suction cylinder penetrates into a soil body through the top plate; the measuring instrument is used for checking the levelness of the suction barrel until the suction barrel penetrates into the soil body by a preset depth. The invention further discloses a suction barrel sinking method. According to the suction barrel sinking method and structure, high-frequency vibration energy emitted by the vibration device is transmitted to the bottom and the soil body in contact with the side face through the supporting ring and the side wall of the suction barrel, the strength of the soil body on the side face and the bottom of the suction barrel can be greatly reduced after the soil body is vibrated, and the suction barrel can conveniently and rapidly penetrate into the soil; therefore, the construction efficiency is greatly improved, and the construction risk is effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of ocean suction cylinder sinking, and in particular relates to a suction cylinder sinking method and structure. Background Art

[0002] With the accelerated development of offshore oil and gas resource exploitation, suction tube foundation, as a new type of offshore foundation structure, is increasingly being used in various fields of offshore facilities due to its advantages such as convenient construction, fast construction speed, reusability and cost-effectiveness.

[0003] The suction cylinder foundation is similar in appearance to a short steel pipe pile with a top cover. The suction cylinder most commonly used in actual projects is a cylindrical structure with a closed upper end and an open lower end. The side walls and top cover are made of steel, and a pumping device and other supporting devices are installed on the top cover. The construction process of the suction cylinder foundation is: component prefabrication, component transportation, positioning and lifting, self-weight sinking, negative pressure sinking, elevation measurement and equipment recovery.

[0004] The process of suction cylinder penetrating the seabed: the suction cylinder sinks freely to the seabed, and the edge of the cylinder is inserted into the seabed soil by its own gravity, forming a sealed space between the suction cylinder and the soil, and then the water in the cylinder is pumped out by an underwater submersible pump, forming an internal and external pressure difference. When the force of the pressure difference on the cylinder is greater than the resistance between the soil and the cylinder, the steel cylinder slowly penetrates the soil. When the top of the cylinder is completely in contact with the seabed soil, the penetration stops, and then the submersible pump is turned off and removed, and the suction cylinder is installed. After the suction cylinder is installed, the negative pressure disappears. At this time, the suction cylinder is actually like a conventional buried short pile, and the bearing capacity mainly depends on the friction between the inner and outer walls of the cylinder and the soil.

[0005] At present, there are many ways to install suction cylinders. Some use the traditional method of sinking the suction cylinder into the seabed, and some install high-pressure water jets and sediment suction ports at the bottom of the suction cylinder, using high-pressure water flow to cut or wash away the soil at the bottom of the cylinder, and penetrate the suction cylinder into the seabed to the designed depth. However, these installation methods are prone to soil plugging and scouring pits, making penetration difficult and costly.

[0006] Therefore, it is urgent to design a suction cylinder sinking method and structure to solve the above-mentioned existing method of installing the suction cylinder, which is prone to soil plugging, scour pit formation, difficulty in penetration, and high cost. Summary of the invention

[0007] In order to solve the technical problems mentioned in the background technology that the existing method of installing suction cylinders is prone to soil plugging, scour pits, difficulty in penetration and high cost, a suction cylinder sinking method and structure are provided to solve the above problems.

[0008] To achieve the above purpose, the specific technical solutions of the suction cylinder sinking method and structure of the present invention are as follows: A suction cylinder sinking structure comprises a suction cylinder, a top plate is arranged at one end of the suction cylinder, a vibration device is overlapped on the top plate, and also comprises a hoist and a measuring instrument. The hoist hoists the suction cylinder and the vibration device to the bottom of the water, and the vibration device vibrates to penetrate the suction cylinder into the soil through the top plate. The measuring instrument is used to check the horizontality of the suction cylinder until the suction cylinder penetrates into the soil to a preset depth.

[0009] Furthermore, a support ring is provided on one end of the suction cylinder, and a fixing clip is provided on the vibration device. The fixing clip is clamped on the support ring to connect the vibration device with the suction cylinder.

[0010] Furthermore, a notch is provided on the fixing clamp, and the notch is plugged into the support ring so that the vibration device fixing clamp is arranged on the support ring.

[0011] Furthermore, a drainage pipe is arranged on the top of the suction cylinder, and when the suction cylinder penetrates into the soil, the seawater in the suction cylinder is discharged from the drainage pipe.

[0012] Furthermore, a lifting lug is provided on the wall of the suction cylinder, and the lifting device lifts the suction cylinder through the lifting lug.

[0013] A suction cylinder sinking method comprises the following steps: S1. A top plate is set at one end of the suction cylinder, and the vibration device is overlapped on the top plate; S2, hoist the suction cylinder and the vibrating device to the bottom of the water; S3. The vibration device vibrates, and the suction cylinder penetrates smoothly into the soil. The measuring instrument on the vibration device observes the horizontality of the suction cylinder until the depth of the suction cylinder penetrating into the soil reaches a preset depth. S4, turn off the vibration device, and separate the vibration device from the suction cylinder; S5. Use a hoist to lift the vibration device onto the construction vessel.

[0014] Furthermore, in S1, a top plate is provided at one end of the suction cylinder, and the vibration device is overlapped on the top plate. A support ring is also provided outside the suction cylinder, and a fixing clip on the vibration device is plugged into the support ring to connect the suction cylinder with the vibration device.

[0015] Furthermore, before the lifting device lifts the suction cylinder and the vibration device to the bottom of the water in S2, the drainage pipe on the top of the suction cylinder is opened in advance, and when the suction cylinder penetrates into the soil, the seawater in the suction cylinder is discharged from the drainage pipe.

[0016] Further, in S3, when the measuring instrument observes that the levelness of the suction cylinder is abnormal, the suction cylinder stops being lowered, and the levelness of the suction cylinder is adjusted until the levelness of the suction cylinder is observed to be normal.

[0017] Furthermore, when the vibration device vibrates in S3, grouting is performed on the top plate of the suction cylinder to increase the overall weight of the suction cylinder.

[0018] The suction cylinder sinking method and structure of the present invention have the following advantages: A top plate is arranged at one end of the suction cylinder, on which a vibration device is overlapped, and also includes a hoist and a measuring instrument. The hoist hoists the suction cylinder and the vibration device to the bottom of the water, and transmits the high-frequency vibration energy emitted by the vibration device to the soil in contact with the bottom and the sides through the support ring and the side wall of the suction cylinder. The strength of the soil on the sides and bottom of the suction cylinder can be greatly reduced after being vibrated, which facilitates the rapid penetration of the suction cylinder into the soil, thereby greatly improving the construction efficiency and effectively reducing the construction risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the suction cylinder sinking structure of the present invention; Figure 2 It is a top view of the suction cylinder sinking structure of the present invention.

[0020] Description of the markings in the figure: 1. Vibration device; 2. Fixing clamp; 3. Support ring; 4. Top plate; 5. Lifting ear; 6. Suction cylinder; 7. Drainage pipe; 8. Soil. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0022] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0023] Please refer to the attached Figure 1 To Attachment Figure 2 The suction cylinder sinking method and structure of the present invention are described.

[0024] At present, the suction cylinder 6 has been successfully applied to many offshore projects. Compared with other offshore foundation forms, it has the following advantages: 1) It has been prefabricated and assembled as a whole on the shore, which is convenient for transportation; 2) During the construction process, it can be quickly installed in place, which speeds up the construction progress, shortens the construction time, saves construction costs, and thus reduces construction risks; 3) It greatly reduces the amount of steel used and significantly reduces costs; 4) It is applicable to most marine structures and different soil types. However, its disadvantages are also obvious: the suction cylinder 6 has weak lateral and vertical stiffness, insufficient self-pullout resistance, and poor self-stability.

[0025] In actual projects, the suction cylinder 6 foundation sinks into place, and the interaction with the surrounding soil 8 is complex, resulting in a large resistance to the suction cylinder 6 sinking. It may not be able to sink to the specified depth relying on the suction cylinder 6 foundation deadweight and negative pressure. Domestic and foreign projects and tests have shown that the reason for most suction cylinder 6 foundation failures is that the foundation tilts during sinking or the sinking depth is insufficient, resulting in insufficient bearing capacity.

[0026] There are many ways to install the suction cylinder 6 at sea. Some use the traditional method to sink the suction cylinder 6 into the seabed. This method has high requirements on the soil quality of the seabed, which can not only ensure the formation of a sealed environment with the cylinder body and no air leakage when the suction cylinder 6 is penetrated, but also ensure that sufficient resistance is provided after the suction cylinder 6 is installed; some install high-pressure water jet ports and sediment suction ports at the bottom of the suction cylinder 6, use high-pressure water flow to cut or wash away the soil 8 at the bottom of the cylinder, and penetrate the suction cylinder 6 into the seabed to the designed depth.

[0027] However, these design solutions have major drawbacks for stable pile platforms, mainly including the following points: 1. Soil plugging is prone to occur. Under the action of the internal and external pressure difference, when the bottom end of the suction cylinder 6 is inserted into the seabed soil 8, the soil 8 inside the suction cylinder 6 bulges upward as the penetration depth of the cylinder increases, which will cause the suction cylinder 6 to fail to penetrate to the designed elevation.

[0028] 2. Scour pits are easily formed. Due to the different degrees of upward bulging of the soil 8 inside the suction cylinder 6, the naturally deposited soil 8 structure is destroyed, resulting in the increase of pores in the soil 8, changing the path of seawater seepage in the soil 8, and thus making it easy for part of the soil 8 around the suction cylinder 6 to be washed away, forming scour pits. The existence of scour pits will greatly reduce the bearing capacity of the suction cylinder 6 and various indicators of the surrounding soil 8, which will affect the use conditions of the suction cylinder 6 and limit its scope of application.

[0029] 3. Difficulty in penetration, easy to fail in installation. When the seabed soil is medium-dense or dense silt or sand (i.e., relatively hard soil 8), if the traditional suction tube 6 basic penetration method is relied upon, a portion of the soil 8 will be penetrated at the beginning, but as the penetration depth increases, the penetration resistance will become very large, resulting in difficulty in penetration; if the seabed soil 8 is uneven and the thickness of the soil layer of the same nature varies greatly, the suction tube 6 will usually tilt, which may seriously lead to failure in the installation of the suction tube 6.

[0030] 4. Increased costs and poor economic efficiency. Using high-pressure water to cut or flush away the soil 8 at the bottom of the cylinder will reduce the bearing capacity of the soil 8 and the frictional resistance to the cylinder, thereby affecting the normal use of the suction cylinder 6. Even the physical and mechanical indicators of the soil 8 cannot be restored or the indicators after restoration are low and cannot meet the design requirements. The cylinder needs to be lengthened to compensate, resulting in an increase in material costs, construction costs, installation costs and other costs.

[0031] Therefore, it is urgent to design a method and structure for sinking the suction cylinder 6 to solve the above-mentioned problems.

[0032] like Figure 1 As shown, the suction cylinder sinking structure in the present invention includes a suction cylinder 6, a top plate 4 is arranged at one end of the suction cylinder 6, a vibration device 1 is overlapped on the top plate 4, and also includes a lifting device and a measuring instrument. The lifting device lifts the suction cylinder 6 and the vibration device 1 to the bottom of the water, and the vibration device 1 vibrates to penetrate the suction cylinder 6 into the soil 8 through the top plate 4. The measuring instrument is used to check the horizontality of the suction cylinder 6 until the suction cylinder 6 penetrates into the soil 8 to a preset depth. In this embodiment, a lifting ear 5 is also arranged on the wall of the suction cylinder 6, and the lifting device lifts the suction cylinder 6 through the lifting ear 5.

[0033] A top plate 4 is arranged at one end of the suction cylinder 6, on which a vibration device 1 is overlapped, and also includes a hoist and a measuring instrument. The hoist hoists the suction cylinder 6 and the vibration device 1 to the bottom of the water, and transmits the high-frequency vibration energy emitted by the vibration device 1 to the soil 8 in contact with the bottom and the sides through the support ring 3 and the side wall of the suction cylinder 6, which can quickly reduce the strength of the soil 8 on the sides and bottom of the suction cylinder 6 after being vibrated, making it convenient for the suction cylinder 6 to quickly penetrate into the soil 8, thereby greatly improving the construction efficiency and effectively reducing the construction risk.

[0034] Further, if Figure 1 and Figure 2As shown, a support ring 3 is provided on one end of the suction cylinder 6, and a fixing clip 2 is provided on the vibration device 1, and the fixing clip 2 is clamped on the support ring 3 to connect the vibration device 1 with the suction cylinder 6. Specifically, a notch is provided on the fixing clip 2, and the notch is plugged with the support ring 3, so that the fixing clip 2 of the vibration device 1 is arranged on the support ring 3, so that the force of the vibration device 1 during vibration is transmitted to the suction cylinder 6 through the support ring 3. In other embodiments, the fixing clip 2 and the support ring 3 can also be connected by bolts or other connection methods, as long as the vibration clip and the support ring 3 can be connected to facilitate the transmission of force.

[0035] The vibration device 1 is used to vibrate the suction cylinder 6 into the soil 8. No internal and external pressure difference is formed, the soil 8 will not bulge upward, and the pores and seepage paths in the soil 8 will not change, so there will be no soil plugging and no scouring pits. The vibration energy emitted by the vibration device 1 is transmitted to the soil 8 in contact with the bottom and sides through the support ring 3 and the side wall of the suction cylinder 6. The strength of the soil 8 on the sides and bottom of the suction cylinder 6 is greatly reduced after being vibrated, which facilitates the rapid penetration of the suction cylinder 6 into the soil 8. There will be no installation failure, and it can be ensured that the penetration depth of the suction cylinder 6 meets the design requirements.

[0036] The huge energy generated by the vibration of the vibration device 1 causes the sand to liquefy or some soft clay to partially collapse, making it easier for the suction cylinder 6 to quickly penetrate the soil 8. The level of the entire device is constantly observed by the measuring instrument installed on the vibration device 1. When a trend of exceeding the standard is found, the lowering should be stopped immediately. After eliminating the abnormal situation, the construction can be continued to ensure that the level of the suction cylinder 6 meets the design requirements until the suction cylinder 6 penetrates the soil 8 to a preset depth.

[0037] Further, if Figure 1 and Figure 2 As shown, a drainage pipe 7 is provided on the top of the suction cylinder 6. When the suction cylinder 6 penetrates into the soil 8, the seawater in the suction cylinder 6 is discharged from the drainage pipe 7. The energy emitted by the vibration device 1 is transmitted to the soil 8 through the suction cylinder 6, causing the sand to liquefy or causing partial subsidence of some soft clay soil. After the suction cylinder 6 penetrates into the soil 8 to a preset depth, the vibration is stopped. When the soil 8 gradually recovers its strength, its density increases and its porosity decreases compared to the situation without vibration. The physical and mechanical indicators of the soil 8 are improved, and the bearing capacity of the soil 8 and the frictional resistance to the suction cylinder 6 are increased. Grouting can be performed in the space between the top plate 4 of the suction cylinder 6 and the drainage pipe 7 to increase the overall weight, play a role of counterpressure, and improve the pull-out resistance of the suction cylinder 6.

[0038] The present invention also discloses a suction cylinder sinking method, comprising the following steps: S1, a top plate 4 is provided at one end of the suction cylinder 6, and the vibration device 1 is overlapped on the top plate 4; S2, hoisting the suction cylinder 6 and the vibration device 1 to the bottom of the water; S3, the vibration device 1 vibrates, the suction cylinder 6 penetrates smoothly into the soil 8, and the measuring instrument on the vibration device 1 observes the horizontality of the suction cylinder 6 until the depth of the suction cylinder 6 penetrating into the soil 8 reaches a preset depth; S4, turning off the vibration device 1, and separating the vibration device 1 from the suction cylinder 6; S5. The hoisting device lifts the vibration device 1 onto the construction vessel.

[0039] By connecting the fixing clamp 2 on the vibration device 1 with the support ring 3, open the drainage channel on the top of the suction cylinder 6 in advance, and then the construction ship uses a sling to lift the entire device including the suction cylinder 6, and keep the entire device steadily lowered to the bottom of the water, turn on the vibration device 1 switch, keep the entire device slowly and steadily lowered, and keep the horizontality of the entire device until the suction cylinder 6 penetrates into the soil 8 to reach the designed depth, open the fixing clamp 2 of the vibration device 1, and separate the suction cylinder 6 from the upper device, and then the lifting ship uses a sling to lift the upper device to the sea surface, and then stably place it on the construction ship and fix it.

[0040] Further, if Figure 1 and Figure 2 As shown, in S1, a top plate 4 is arranged at one end of the suction cylinder 6, and the vibration device 1 is overlapped on the top plate 4. It also includes a support ring 3 arranged and installed on the outer surface of the suction cylinder 6, and the fixing clip 2 on the vibration device 1 is plugged into the support ring 3 to connect the suction cylinder 6 with the vibration device 1. The vibration device 1 is fixed to the support ring 3 by the fixing clip 2. The vibration device 1 can operate underwater and can be used in deep water areas. A suitable suction cylinder 6 can be selected according to specific geological conditions, such as different cylinder diameters, cylinder lengths, cylinder wall thicknesses, etc. of the suction cylinder 6 and the matching vibration device 1, so as to facilitate the suction cylinder 6 to penetrate into the soil 8 until the design elevation is reached to meet the design requirements.

[0041] Further, if Figure 1 and Figure 2 As shown, before the lifting device lifts the suction cylinder 6 and the vibration device 1 to the bottom of the water in S2, the drainage pipe 7 on the top of the suction cylinder 6 is opened in advance, and when the suction cylinder 6 penetrates into the soil 8, the seawater in the suction cylinder 6 is discharged from the drainage pipe 7. The drainage pipe 7 on the top of the suction cylinder 6 is opened in advance by connecting the fixing clamp 2 of the vibration device 1 with the support ring 3, and then the construction ship uses the lifting device to lift the entire device including the suction cylinder 6, and keep the entire device steadily lowered to the bottom of the water, turn on the switch of the vibration device 1, keep the entire device slowly and steadily lowered, and keep the horizontality of the entire device, and the seawater in the suction cylinder 6 is discharged from the drainage pipe 7 until the suction cylinder 6 penetrates into the soil 8 to a preset depth, open the fixing clamp 2 of the vibration device 1, and separate the suction cylinder 6 from the vibration device 1, and then the lifting ship uses the lifting device to lift the vibration device 1 to the sea surface, and then stably places it on the construction ship and fixes it.

[0042] Further, if Figure 1 and Figure 2 As shown, in S3, when the measuring instrument observes that the levelness of the suction cylinder 6 is abnormal, the suction cylinder 6 stops lowering and adjusts the levelness of the suction cylinder 6 until the levelness of the suction cylinder 6 is observed to be normal. In S3, when the vibration device 1 vibrates, grouting is performed at the top plate 4 of the suction cylinder 6 to increase the overall weight of the suction cylinder 6, play a counter-pressure role, and improve the pull-out resistance of the suction cylinder 6.

[0043] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A suction cylinder sinking structure, characterized in that: It includes a suction cylinder, a top plate is arranged at one end of the suction cylinder, a vibration device is overlapped on the top plate, and also includes a hoist and a measuring instrument. The hoist hoists the suction cylinder and the vibration device to the bottom of the water, and the vibration device vibrates to penetrate the suction cylinder into the soil through the top plate. The measuring instrument is used to check the horizontality of the suction cylinder until the suction cylinder penetrates into the soil to a preset depth.

2. The suction cylinder sinking structure according to claim 1, characterized in that: A supporting ring is provided on one end of the suction cylinder, and a fixing clip is provided on the vibration device. The fixing clip is clamped on the supporting ring to connect the vibration device with the suction cylinder.

3. The suction cylinder sinking structure according to claim 2, characterized in that: A notch is provided on the fixing clamp, and the notch is plugged into the supporting ring so that the fixing clamp of the vibration device is arranged on the supporting ring.

4. The suction cylinder sinking method according to claim 1, characterized in that: A drainage pipe is arranged on the top of the suction cylinder. When the suction cylinder penetrates into the soil, the seawater in the suction cylinder is discharged from the drainage pipe.

5. The suction cylinder sinking structure according to claim 1, characterized in that: Lifting ears are also provided on the wall of the suction cylinder, and the lifting device lifts the suction cylinder through the lifting ears.

6. A suction cylinder sinking method, characterized in that: The steps include: S1. A top plate is set at one end of the suction cylinder, and the vibration device is overlapped on the top plate; S2, hoist the suction cylinder and the vibrating device to the bottom of the water; S3. The vibration device vibrates, and the suction cylinder penetrates smoothly into the soil. The measuring instrument on the vibration device observes the horizontality of the suction cylinder until the depth of the suction cylinder penetrating into the soil reaches a preset depth. S4, turn off the vibration device, and separate the vibration device from the suction cylinder; S5. Use a hoist to lift the vibration device onto the construction vessel.

7. The suction cylinder sinking method according to claim 6, characterized in that: In S1, a top plate is arranged at one end of the suction cylinder, and a vibration device is overlapped on the top plate. A support ring is arranged outside the suction cylinder, and a fixing clip on the vibration device is plugged into the support ring to connect the suction cylinder with the vibration device.

8. The suction cylinder sinking method according to claim 6, characterized in that: Before the lifting device in S2 lifts the suction cylinder and the vibration device to the bottom of the water, the drainage pipe on the top of the suction cylinder is opened in advance. When the suction cylinder penetrates into the soil, the seawater in the suction cylinder is discharged from the drainage pipe.

9. The suction cylinder sinking method according to claim 6, characterized in that: In S3, when the measuring instrument observes that the levelness of the suction cylinder is abnormal, the suction cylinder stops being lowered, and the levelness of the suction cylinder is adjusted until the levelness of the suction cylinder is observed to be normal.

10. The suction cylinder sinking method according to claim 6, characterized in that: When the vibration device vibrates in S3, grouting is performed at the top plate of the suction cylinder to increase the overall weight of the suction cylinder.

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