CN111236197A - Bottom-sitting self-elevating platform and pile inserting method - Google Patents

Bottom-sitting self-elevating platform and pile inserting method Download PDF

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Publication number
CN111236197A
CN111236197A CN202010173500.0A CN202010173500A CN111236197A CN 111236197 A CN111236197 A CN 111236197A CN 202010173500 A CN202010173500 A CN 202010173500A CN 111236197 A CN111236197 A CN 111236197A
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China
Prior art keywords
platform
pile
legs
floating body
lower floating
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CN202010173500.0A
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Chinese (zh)
Inventor
晁世方
汤晶
姜树卫
赖蕾
黄曌宇
于多
董美余
李加坤
刘小亮
施海滨
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Shanghai Zhenghua Heavy Industries Co Ltd
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Shanghai Zhenghua Heavy Industries Co Ltd
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Priority to CN202010173500.0A priority Critical patent/CN111236197A/en
Publication of CN111236197A publication Critical patent/CN111236197A/en
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    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B17/04Equipment specially adapted for raising, lowering, or immobilising the working platform relative to the supporting construction
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B17/04Equipment specially adapted for raising, lowering, or immobilising the working platform relative to the supporting construction
    • E02B17/08Equipment specially adapted for raising, lowering, or immobilising the working platform relative to the supporting construction for raising or lowering
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B2017/0056Platforms with supporting legs

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)

Abstract

The invention discloses a bottom-sitting self-elevating platform and a pile inserting method, wherein the pile inserting method of the bottom-sitting self-elevating platform comprises the following steps: step S10: the platform is shifted to a designated position; step S20: pre-extending pile legs; step S30: the floating body is put down to the seabed; step S40: lifting the upper hull away from the water; step S50: preloading the lower floating body to a target load; step S60: pre-loading the pile leg to a target load; step S70: the upper hull is raised to the working air gap. The method for inserting the pile into the bottom-sitting self-elevating platform does not need to inject a large amount of ballast water, solves the problem of poor stability of the platform caused by surge invasion, and is suitable for soft texture; in addition, the platform is more stable through a mode that the lower floating body and the pile legs bear together and the load is adjustable.

Description

Bottom-sitting self-elevating platform and pile inserting method
Technical Field
The invention relates to the field of ocean engineering platforms, in particular to a bottom-sitting self-elevating platform and a pile inserting method, which are mainly used for realizing ocean resource development.
Background
The ocean engineering platform is necessary equipment for realizing ocean resource development, such as a drilling platform for exploiting oil and gas, a construction platform for installing offshore wind power equipment and a special accommodation platform; before the platform starts formal operation, the foundation must be compacted through pile insertion or similar processes, so that the platform can resist the maximum support reaction force generated under the storm condition or the operation condition, and the dangers of sudden settlement of pile legs and the like are prevented.
The self-elevating platform and the bottom-sitting platform are two typical types of ocean engineering platforms, and the problems in pile inserting or bottom-sitting operation are as follows:
the traditional self-elevating platform is provided with a plurality of independent pile legs, the ship body is lifted to leave the water surface by inserting the pile legs into the seabed, the attack of waves and currents is avoided, the self-elevating platform is suitable for harder geology, but for soft geology, the pile legs are inserted deeply, in the process of inserting piles, namely the pile legs into the seabed, for certain 'hard-soft-hard' special geology, the puncture risk is easy to occur, the bottom ends of the pile legs are provided with pile shoes with larger areas, and the problem of difficult pile pulling exists because the pile pulling resistance is required to be overcome when the piles are pulled out.
The traditional bottom-sitting type platform is connected with the lower floating body and the main ship body through a plurality of stand columns, a large amount of ballast water is injected to seat the lower floating body on the seabed, and construction operation is started after the foundation is compacted. The mode has the following disadvantages: 1. the time for injecting ballast water is long, and the operation efficiency is influenced; 2. the plurality of upright columns can be subjected to great hydrodynamic force, particularly horizontal load caused by surge, so that the stability of the lower floating body on the seabed is poor; 3. when the lower floating body is deeply buried in mud in softer geology, the problem of difficult bottom removal exists.
For the problem that solves above-mentioned two kinds of platforms existence, the self-elevating platform of sitting at the bottom of a brand-new theory is created, like a sit at the bottom of the disclosed wind-powered electricity generation pile driving ship in application number 201721469034.0, include: an upper hull; the crane is arranged on the upper ship body; the pile legs are arranged on the upper ship body; the lower floating body is connected with the pile leg; the bottom-sitting self-elevating wind power pile driving ship floats, the upper ship body floats on the water surface, the pile legs are retracted, the lower floating body is retracted to the bottom of the upper ship body, and the lower floating body is positioned below the water surface; the bottom-sitting self-elevating wind power pile driving ship stands, pile legs extend out, the lower floating body sinks to the seabed, the lower floating body is fixed on the seabed, the upper ship body is jacked up by the pile legs, and the upper ship body is separated from the water surface. However, how to realize stable pile insertion during operation of the bottom-mounted self-elevating wind power pile driving vessel needs further research and solution. At present, only relevant data about pile inserting and pre-loading of the jack-up platform can be inquired, for example, a pile pressing standing method of the jack-up platform disclosed in application number 201811136175.X comprises the following steps: firstly, towing the platform to a preset operation position, and putting down pile legs to a mud surface; step two, adopting single pile leg action to adjust the posture of the platform, and ensuring the trim and transverse inclination angle of the platform; starting a lifting device, slowly lifting the platform, and stopping lifting the platform when the bottom surface of the platform is away from the water surface by a proper distance; and step four, observing each pile leg for a period of time, and determining that each pile leg starts preloading after being stabilized. And application No. 201020648786.5 discloses an offshore jack-up drilling platform pile inserting and pile pulling automatic control device, jack-up drilling platform pile leg system includes the spud leg and installs the pile shoe in the spud leg bottom, and this automatic control device includes displacement sensor, force transducer, computer monitoring control system, ballast pump switch, pile pulling operation control switch and pile punching valve, displacement sensor and force transducer install on the chord member of spud leg, ballast pump switch installs the ballast pump control system department at the ballast compartment, pile pulling operation control switch locates in the deck control room to the drainage switch of ballast compartment when controlling the pile pulling operation, this pile punching valve is installed on the spud shoe and is continuous with the pile punching pipeline, displacement sensor measures the pile body and goes into the mud degree of depth, force transducer measures spud leg bearing capacity and pile pulling force, displacement sensor and the measured data of force transducer in pile inserting and pile pulling process transmit computer monitoring control system, so as to control the ballast pump switch, the pile flushing valve and the pile pulling operation control switch. But the piles and ballast for a submersible jack-up platform are still empty.
In view of the above, there is a need to develop a novel bottom-supported self-elevating platform and a pile inserting method, which do not require a large amount of ballast water to be injected, and can solve the problem of poor platform stability caused by surge invasion and attack, and is also suitable for soft texture.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a bottom-sitting self-elevating platform and a pile inserting method, which do not need to inject a large amount of ballast water, can solve the problem of poor platform stability caused by surge invasion and are suitable for soft texture; in addition, the platform is more stable through a mode that the lower floating body and the pile legs bear together and the load is adjustable.
In order to achieve the purpose, the invention adopts the following technical scheme:
according to one aspect of the invention, there is provided a submersible self-elevating platform comprising an upper hull, legs, and a lower buoy,
the platform also comprises a lifting mechanism and a locking mechanism,
the pile legs penetrate through the upper hull and the lower floating body;
the lifting mechanism is arranged on the upper ship body to realize the relative motion of the pile legs and the upper ship body;
the locking mechanism is arranged on the lower floating body to realize that the pile leg and the lower floating body are relatively static;
the platform floats, the upper ship body floats on the water surface, the pile legs are retracted, the lower floating body is retracted to the bottom of the upper ship body, and the lower floating body is positioned below the water surface;
the platform stands, the pile legs extend out of the lower floating body, the lower floating body sinks to the seabed, and the pile legs are inserted into the seabed to fix the lower floating body; the upper hull is lifted by the spud legs and is separated from the water surface.
Preferably, the shift position of the lock mechanism is not higher than 6000 t.
Preferably, ballast water is filled or discharged into or from the lower float to adjust the center of gravity of the lower float.
Preferably, four pile legs are symmetrically arranged on the upper hull and the lower floating body.
Preferably, a monitoring mechanism is arranged on the platform.
According to another aspect of the present invention, there is provided a method of piling a submersible jack-up platform as described in the first aspect,
the method comprises the following steps:
step S10: the platform is shifted to a designated position;
step S20: pre-extending pile legs;
step S30: the floating body is put down to the seabed;
step S40: lifting the upper hull away from the water;
step S50: preloading the lower floating body to a target load;
step S60: pre-loading the pile leg to a target load;
step S70: the upper hull is raised to the working air gap.
Preferably, in step S10, the lower floating body is retracted to the bottom of the upper hull before the platform is displaced.
Preferably, in step S20, when the legs are pre-extended, the locking mechanisms of the two legs on one diagonal of the platform are in a working state, and the two legs on the other diagonal are subjected to a "leg lowering" operation, so that the two legs are pre-extended by a predetermined distance; and repeating the steps to complete the pre-stretching of the residual pile legs.
Preferably, ballast water is injected into the lower buoy prior to pre-extension of the legs to lower the platform center of gravity.
Preferably, the predetermined distance is 5m ± 0.5 m.
Preferably, in the step S30, the locking mechanism is adjusted to the working state; the operation of pile leg descending is adopted, and simultaneously the lower floating body is put down to the seabed.
Preferably, in step S40, the upper hull is subjected to a "platform up" operation to lift the upper hull off the water surface to a predetermined air gap height.
Preferably, the predetermined air gap height is 0.5m ± 0.1 m.
Preferably, in step S50, a diagonal preloading operation is performed, the locking mechanisms of two legs on one diagonal of the platform are adjusted to a working state, a "leg raising" operation is performed on two legs on the other diagonal until the floating body reaches a target load under the preloaded diagonal, and pressure is maintained for a period of time until the platform is stable; and repeating the steps to finish the pre-loading of the floating body under the rest diagonal.
Preferably, in step S50, the whole pre-loading operation is performed, and ballast water is injected into the upper hull to make the lower hull reach the target load, and the pressure is maintained for a period of time until the platform is stable.
Preferably, in step S60, a diagonal preloading operation is performed, the two leg locking mechanisms on one diagonal of the platform are adjusted to the highest gear, after the locking mechanisms on the two legs on the other diagonal are adjusted to a predetermined gear, a "leg descending" operation is performed until the bottom of the preloaded leg reaches a target load, and pressure is maintained for a period of time until the platform is stable; and repeating the steps to finish the pre-loading of the rest pile legs.
Preferably, in step S60, the load condition of the bottom of the pile leg is monitored in real time by a monitoring mechanism.
Preferably, in step S70, the upper hull is lifted to the working air gap by performing a "platform up" operation on the upper hull.
Preferably, in the steps S20, S30, and S40, the inclination angle of the platform is monitored in real time by a monitoring mechanism, and when the inclination angle is greater than a predetermined angle, the inclination angle is adjusted by adjusting ballast water in the upper hull.
Preferably, the predetermined angle is 0.3 °.
The invention has the beneficial effects that:
1. the invention relates to a bottom-sitting self-elevating platform, which is provided with an upper hull and a lower floating body which are connected through pile legs, and a lifting mechanism and a locking mechanism which are arranged on the upper hull and the lower floating body, so that the upper hull and the lower floating body can be opened and closed;
2. according to the bottom-sitting self-elevating platform, the pile legs extend out of the lower floating body and are inserted into the seabed, the upper ship body is lifted to leave the water surface, surging invasion can be avoided, the lower floating body provides huge buoyancy and bottom-sitting area, the lower floating body and the pile legs inserted into the seabed share the vertical load and bending moment brought by the upper ship body, and the bottom-sitting self-elevating platform is suitable for softer geology;
3. according to the bottom-sitting self-elevating platform, the lower floating body is fixedly connected with the pile legs under the set load, and the load bearing capacity of the bottom-sitting self-elevating platform can be adjusted in a grading manner, so that the load distribution between the lower floating body and the pile legs is realized;
4. according to the method for inserting the pile into the bottom-sitting self-elevating platform, the pile legs are pre-extended for a certain distance, so that when the lower floating body is located on the seabed, the quick pile inserting positioning is realized, and the platform is prevented from slipping;
5. according to the method for inserting the pile into the bottom-sitting self-elevating platform, the foundation is gradually compacted through preloading of the lower floating body and the pile legs, so that the platform is more stable;
6. the bottom-sitting self-elevating platform provided by the invention is always loaded by the lower floating body in the pile inserting process, so that the risk of platform inclination caused by sudden settlement of a certain pile leg can be avoided.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a schematic flow diagram of a method of inserting piles in a bottom-supported self-elevating platform according to the present invention;
FIG. 2 is a schematic view of a pedestal jack-up platform leg marker of the present invention;
fig. 3 is a schematic diagram of step S10 in the method for inserting piles in a submersible jack-up platform according to the present invention;
fig. 4 is a schematic diagram of step S20 in the method for inserting piles in a submersible jack-up platform according to the present invention;
fig. 5 is a schematic diagram of step S30 in the method for inserting piles in a submersible jack-up platform according to the present invention;
fig. 6 is a schematic diagram of step S40 in the method for inserting piles in a submersible jack-up platform according to the present invention;
fig. 7 is a schematic diagram of step S50 in the method for inserting piles in a submersible jack-up platform according to the present invention;
fig. 8 is a schematic diagram of step S60 in the method for inserting piles in a submersible jack-up platform according to the present invention;
fig. 9 is a schematic diagram of step S70 in the method for inserting piles in a submersible jack-up platform according to the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way.
According to one aspect of the present invention, a submersible jack-up platform is provided.
As shown in fig. 2, the submersible jack-up platform 10 provided in the present embodiment includes an upper hull 101, a lower hull 102, legs 103, a lifting mechanism 104, and a locking mechanism 105; the pile legs 103 penetrate through the upper ship body 101 and the lower floating body 102, are connected with the upper ship body 101 through the lifting mechanism 104 and are connected with the lower floating body 102 through the locking mechanism 105, and the number of the pile legs 103 is 4, and the pile legs are symmetrically arranged on the upper ship body 101 and the lower floating body 102; the pile leg 103 and the upper hull 101 move relatively by starting the lifting mechanism 104; the pile leg 103 and the lower floating body 102 are relatively static by enabling the locking mechanism 105 to be in a working state; the shift position of the lock mechanism 105 is not higher than 6000 t; the self-elevating platform 10 is also provided with a monitoring mechanism 106, which is convenient for monitoring the state and stress condition of each part on the self-elevating platform 10 during pile inserting.
The monitoring mechanism 106 comprises an inclination angle monitoring mechanism, a load monitoring mechanism and a depth monitoring mechanism, and the monitoring mechanism 106 is arranged on the bottom-seated self-elevating platform 10 (see fig. 3); the inclination angle monitoring mechanism is arranged on the bottom-sitting self-elevating platform 10 and is used for monitoring the inclination angles of the upper ship body 101 and the lower floating body 102; the load monitoring mechanism is arranged on the self-elevating platform 10 and is used for monitoring the load and stress conditions of the pile legs 103, the lower floating body 102, the lifting mechanism 104 and the locking mechanism 105; the depth monitoring mechanism is arranged on the bottom-sitting self-elevating platform 10 and used for monitoring the launching depth and the mud entering depth of the pile leg 103.
When the bottom-sitting self-elevating platform 10 floats (see fig. 3), the upper hull 101 floats on the water surface, the pile legs 103 are retracted, the lower float 102 is retracted to the bottom of the upper hull 101, and the lower float 102 is positioned below the water surface; when the submersible jack-up platform 10 is standing (see fig. 9), the spud legs 103 are extended, the lower floating body 102 is sunk onto the seabed, the lower floating body 102 is fixed on the seabed, the spud legs 103 are inserted into mud on the seabed, the upper hull 101 is lifted by the spud legs 103, and the upper hull 101 is separated from the water.
During the pile insertion of the submersible jack-up platform 10, the center of gravity of the lower hull 102 may be adjusted by injecting or discharging ballast water into or from the lower hull 102; the horizontal inclination angle of the submersible jack-up platform 10 is adjusted by adjusting the ballast water in the upper hull 101.
For the analysis of a single pile leg 103, when a lifting mechanism 104 on the pile leg 103 is started, the pile leg 103 is lifted or lowered relative to the upper hull 101; when the locking mechanism 105 on the spud leg 103 is in an operating state, the spud leg 103 is stationary relative to the upper hull 101; relative movement of the legs 103, the upper hull 101 and the lower float 102 is achieved by adjustment of the lifting mechanism 104 and the locking mechanism 105.
The floating state shown in fig. 3, the submersible jack-up platform 10 is floating on the water for maneuvering and towing; the standing state shown in fig. 9 is an operation state, the lower floating body 102 is sunk to the seabed by the lifting mechanism 104 and the locking mechanism 105, the pile leg 103 is inserted into the mud of the seabed, and the submersible self-elevating platform 10 is realized to resist horizontal load by virtue of the lower floating body 102 and horizontal shearing force between the pile leg 103 and the seabed; the bottom-mounted self-elevating platform 10 is suitable for seabed with different textures by means of huge buoyancy and bottom-mounted area provided by the lower floating body 102 and vertical load and bending moment brought by an upper hull borne by the pile legs 103 inserted into the seabed; meanwhile, the upper hull 101 is lifted away from the water surface, so that the surge invasion can be avoided.
According to another aspect of the present invention there is provided a method of piling a submersible jack-up platform as described in the first aspect.
As shown in fig. 1, a method for inserting piles into a submersible jack-up platform includes the following steps:
step S10: the platform is shifted to a designated position
The upper hull 101 and the lower hull 102 are combined into a whole, the pile legs 103 are retracted to a towing position, and the platform is shifted to a designated position. The state of the submersible jack-up platform 10 is shown in fig. 3.
Step S20: pre-extending leg 103
Before the pile legs 103 are pre-extended, ballast water is injected into the lower floating body 102 to lower the center of gravity of the platform; when the pile legs 103 are pre-extended, the locking mechanisms 105 of the two pile legs 103 on one diagonal of the platform are in a working state, and the two pile legs 103 on the other diagonal are subjected to the operation of 'pile leg descending', so that the two pile legs 103 are pre-extended to a preset distance; repeating the steps to complete the pre-extension of the rest pile legs 103; by pre-extending the pile leg 103, when the bottom of the lower floating body 102 is located on the seabed, rapid pile inserting positioning is realized, and the platform is prevented from sliding. The state of the submersible jack-up platform 10 is shown in fig. 4.
Step S30: lower float 102
Before the floating body 102 is put down, the horizontal inclination angle of the upper ship body 101 and the lower floating body 102 is monitored through an inclination angle monitoring mechanism, and if the horizontal inclination angle is larger than a preset angle of 0.3 degrees, ballast water in the upper ship body 101 can be adjusted to adjust the horizontal inclination angle of the upper ship body 101 and the lower floating body 102 to be within 0.3 degrees; adjusting the locking mechanism 105 to an operating state; the "leg down" operation is taken while lowering the lower buoy 102 to the seabed. The state of the submersible jack-up platform 10 is shown in fig. 5.
Step S40: raise the upper hull 101 off the water
Adjusting the inclination angle of the platform to be within 0.3 degrees; the upper hull 101 is taken a "platform up" operation to lift the upper hull 101 off the water to a predetermined air gap height. The state of the submersible jack-up platform 10 is shown in fig. 6.
Step S50: preloading the lower float 102 to a target load
Preloading the lower floating body 102 by adopting diagonal preloading operation, adjusting locking mechanisms 105 of two pile legs 103 on one diagonal of the platform to be in a working state, adopting 'pile leg lifting' operation on the two pile legs 103 on the other diagonal until the preloaded diagonal lower floating body 102 reaches a target load, and maintaining the pressure for a period of time until the platform is stable; and repeating the steps to finish the pre-loading of the residual diagonal lower floating body 102. The state of the submersible jack-up platform 10 is shown in fig. 7.
Or the integral pre-loading operation is adopted, the lower floating body 102 is enabled to reach the target load by injecting ballast water into the upper ship body 101, and the pressure is maintained for a period of time until the platform is stable.
Step S60: preloading legs 103 to target load
Pre-loading the pile legs 103 by adopting diagonal pre-loading operation, adjusting the locking mechanisms 105 of the two pile legs 103 on one diagonal of the platform to the highest gear, adjusting the locking mechanisms 105 of the two pile legs 103 on the other diagonal to a preset gear, then adopting 'pile leg descending' operation until the bottom of the pre-loaded pile leg 103 reaches a target load, and maintaining the pressure for a period of time until the platform is stable; repeating the steps to finish the pre-loading of the rest pile legs 103; in the process, the load condition of the bottom of the pile leg 103 is monitored in real time through a load monitoring mechanism. The state of the submersible jack-up platform 10 is shown in fig. 8.
Step S70: lifting the upper hull 101 to the working air gap
The upper hull 101 is lifted to the working air gap by a "platform up" operation. The state of the submersible jack-up platform 10 is shown in fig. 9.
The steps are as follows: the term "leg down" refers to the lowering of the legs 103 relative to the upper hull 101 by actuating the lifting mechanism 104.
The term "leg-up" means that the elevating mechanism 104 is actuated to raise the legs 103 relative to the upper hull 101.
The term "platform up" means that the lifting mechanism 104 is activated to raise the upper hull 101 relative to the legs 103.
Dwell pressure refers to maintaining the load transferred to the foundation for a period of time to facilitate compaction of the foundation.
Example 1
Taking a 2500t lifting capacity sitting-bottom self-elevating platform as an example, the pile inserting method is explained in detail and comprises the following specific steps:
step S10: the platform is shifted to a designated position.
Before the platform is shifted, exploration and sea sweeping work are carried out on geology in an operation area in advance, information such as geological conditions and submarine topography of each operation place is mastered, and the operation conditions of the bottom-sitting self-elevating platform 10 are met.
The platform is moved to a corresponding construction position through a tugboat or by self, the state at the moment is as shown in figure 3, the upper hull 101 and the lower float 102 are combined into a whole, the lower float 102 and the pile leg 103 are retracted to a towing position, the gear of a locking mechanism 105 which is responsible for connecting the lower float 102 and the pile leg 103 is set to be a highest gear 6000t, and the platform is ensured to be positioned at a designated position by adopting a dynamic positioning or anchoring positioning mode.
Step S20: pre-extending legs 103.
According to the geological conditions of the operation place, before the floating body 102 is put down, the four pile legs 103 need to be pre-extended for a distance of 5m in advance, when the bottom of the lower floating body 102 is located on the seabed, the pre-extended pile legs 103 can realize the function of rapid pile inserting and positioning, the platform is prevented from sliding under the influence of environmental loads such as stormy waves and currents, and the safety of the platform is ensured.
According to the needs of sinking and floating stability, before the pile legs 103 are pre-extended, a proper amount of ballast water needs to be injected into the lower floating body 102 so as to reduce the height of the center of gravity of the platform and prevent the platform from overturning in the sinking and floating process of the lower floating body 102.
The net buoyancy of the lower floating body 102 is upward, the obtained pressure load water amount of the lower floating body is monitored through the monitoring mechanism 106, the net buoyancy of the lower floating body is 8000t through integrating the water displacement of the lower floating body and the dead weight, the locking mechanism 105 which is responsible for connecting the lower floating body 102 and the pile leg 103 is fixedly arranged on the upper surface of the lower floating body 102 and always bears upward counter force 2000t, and the pile leg 103 can be pre-stretched in a diagonal processing mode.
For ease of description, the four legs 103 are labeled 103A, 103B, 103C, 103D differently, as shown in fig. 2. Before the pile legs 103 are pre-extended, the platform is adjusted to be basically horizontal, the horizontal inclination angle of the upper hull 101 is optimally ensured to be within 0.3 degrees, the locking mechanisms 105 at the pile legs 103A and 103D are opened, at the moment, the locking mechanisms 105 at the pile legs 103A and 103D are in a non-working state, the locking mechanisms 105 at the pile legs 103B and 103C are in a working state, then the lifting mechanisms 104 at the pile legs 103A and 103D of the upper hull 101 are started, and the pile legs 103A and 103D are operated to be in a 'pile leg descending' mode until the pile legs 103A and 103D are reduced by 5m +/-0.5 m compared with the initial height.
And repeating the steps, opening the locking mechanisms 105 at the pile legs 103B and 103C, enabling the locking mechanisms 105 at the pile legs 103B and 103C to be in a non-working state, enabling the locking mechanisms 105 at the pile legs 103A and 103D to be in a working state, starting the lifting mechanisms 104 at the pile legs 103B and 103C of the upper hull 101, and performing 'pile leg descending' operation on the pile legs 103B and 103C until the pile legs 103B and 103C are reduced by 5m +/-0.5 m from the initial height. At this point, the pre-extension leg 103 action is complete, as shown in fig. 4.
Step S30: the floating body 102 is lowered to the seabed.
Before the floating body 102 is put down, the horizontal inclination angles of the upper ship body 101 and the lower floating body 102 are monitored through an inclination angle monitoring mechanism, when the inclination angles of the upper ship body 101 and the lower floating body 102 are larger than a preset angle of 0.3 degrees, the inclination angles of the upper ship body 101 and the lower floating body 102 can be adjusted by adjusting ballast water in the upper ship body 101, and the same inclination angles of the upper ship body 101 and the lower floating body 102 and the preset angle of not larger than 0.3 degrees are ensured so as to ensure that a platform is stable; it is confirmed that the locking mechanisms 105 of all four legs 103 are at the highest 6000 tonne setting.
The lifting mechanisms 104 at the four pile legs 103 of the upper hull 101 are started simultaneously, and the 'pile leg descending' action is taken, so that the floating body 102 must be synchronously put down at the same time, and the phenomenon that the pile legs 103 and the lower floating body 102 are blocked due to the fact that the putting speeds are inconsistent is avoided.
Continuing to lower the floating body 102 until the pile legs 103 touch the bottom seabed, closely paying attention to the lowering height of the pile legs 103, prejudging the bottom touching state of the pile legs 103 according to water depth data monitored by the depth monitoring mechanism in real time, and judging the sequence of the mud entering of the pile legs 103 by observing draft display at four corners of the upper hull 101, such as that the draught of a left side of a bow part is reduced, the pile legs 103A touch the bottom, the draught of a right side of a stern part is reduced, the pile legs 103D are also touched, and the like until all four pile legs 103 are in mud and the lower floating body 102 is located on the seabed; in the process, the inclination angle of the platform is required to be always kept within 0.3 degrees. At this time, the state of the submersible jack-up platform 10 is as shown in fig. 5.
Step S40: the upper hull 101 is lifted out of the water.
After the lower float 102 is seated on the seabed, the gear of the locking mechanism 105 on the four legs 103 is still set to 6000 t. Confirming that the inclination angle of the upper hull 101 is within 0.3 degrees, the loading of each lifting mechanism 104 of the upper hull 101 is within a rated lifting range, and reserving enough internal circulation ballast water in a ballast tank of the upper hull 101 for the lifting process. And simultaneously starting the lifting mechanisms 104 at the four pile legs 103 of the upper hull 101 to lift the upper hull 101 away from the water surface, wherein in the process, the stress of the locking mechanism 105 at a single pile leg 103 is 5500t, and the loads of the upper hull 101 and the pile legs 103 are transmitted to the lower hull 102 through the locking mechanism 105, so that the mud entering depth of the lower hull 102 is continuously increased, and the mud entering depth can be monitored in real time through the depth monitoring mechanism.
After the upper hull 101 is lifted until the bottom plate of the vessel leaves the water surface, the air gap height is maintained at 0.5m +/-0.1 m, and the small air gap height is set to mainly prevent the risk of platform inclination caused by uncompacted foundation during pile insertion. The completed squat bottom jack-up platform 10 is shown in figure 6.
Step S50: the lower float 102 is pre-loaded to a target load. (Pre-loading with diagonal)
In order to ensure the working safety of the platform, the foundation at the bottom of the lower floating body 102 and the foundation at the bottom of the pile leg 103 need to be compacted, according to the calculation result of the support reaction force in this example, a single pile leg 103 needs to be preloaded to a support reaction value of 10000t, the bearing ratio of the locking mechanism 105 to the bottom end of the pile leg 103 is set to 6: 4, the locking mechanism 105 at each pile leg 103 and the lower floating body 102 connected with the locking mechanism need to be preloaded to 6000t, and the bottom of the pile leg 103 needs to be preloaded to 4000 t. The preloading of the whole platform is divided into two steps of preloading of the lower floating body 102 and preloading of the pile legs 103.
The stress of the locking mechanisms 105 at the four pile legs 103 is 5500t, and the stress of the lifting mechanism 104 of the upper hull 101 is 4500 t.
The diagonal preloading of the lower float 102 is achieved by operating the lifting mechanism 104 of the upper hull 101 with diagonal preloading, as follows:
confirming that the locking mechanisms 105 at the spud legs 103A and 103D are in a working state and at the highest gear 6000 t; then, the lifting mechanisms 104 at the pile legs 103B and 103C are started, and the pile legs 103B and 103C are subjected to a pile leg lifting action until the stress of the lifting mechanisms 104 reaches 4000 t; along with load transfer, the stress of the lifting mechanisms 104 at the pile legs 103A and 103D is 5000t, the stress of the locking mechanisms 105 at the pile legs 103A and 103D is 6000t, the pressure is maintained for a period of time, the height of the air gap and the mud penetration depth of the lower floating body 102 are observed until the height of the air gap and the mud penetration depth of the lower floating body 102 are not changed any more, the platform is stable, and the pre-loading of the lower floating body 102 at the pile legs 103A and 103D is judged to be finished.
Repeating the steps, and confirming that the locking mechanisms 105 at the pile legs 103B and 103C are in the working state and at the highest gear 6000 t; then, the lifting mechanisms 104 at the pile legs 103A and 103D are started, and the pile legs 103A and 103D are subjected to a pile leg lifting action until the stress of the lifting mechanisms 104 reaches 4000 t; along with load transfer, the stress of the lifting mechanisms 104 at the pile legs 103B and 103C is 5000t, the stress of the locking mechanisms 105 at the pile legs 103B and 103C reaches 6000t, the pressure is maintained for a period of time, the height of the air gap and the mud penetration depth of the lower floating body 102 are observed until the height of the air gap and the mud penetration depth of the lower floating body 102 are not changed any more, the platform is stable, and the fact that the preloading of the lower floating bodies 102 at the pile legs 103B and 103C is completed is judged.
After the pre-loading of the lower floating body 102 is completed, the height of the air gap of the upper hull 101 is continuously adjusted to 0.5m ± 0.1m, and the state of the bottom-mounted self-elevating platform 10 is shown in fig. 7.
Step S60: pre-loading the legs 103 to the target load.
Preloading is carried out on the pile legs 103 in a diagonal preloading mode, the load setting of the locking mechanisms 105 at the two diagonal pile legs 103 is adjusted, and the two pile legs 103 are operated in a 'pile leg descending' mode, so that redundant vertical load is transmitted to the bottoms of the pile legs 103.
Preloading pile legs 103A, 103D to bottom load 4000 t: confirming that the locking mechanisms 105 at the spud legs 103B and 103C are in the working state and at the highest gear 6000 t; the gears of the locking mechanisms 105 at the pile legs 103A and 103D are adjusted in a grading manner, the difference value between each grade can be set to be 500t better until the stress of the locking mechanisms 105 of the pile legs 103A and 103D is 1500 t; and then starting the lifting mechanisms 104 at the pile legs 103A and 103D of the upper hull 101, performing 'pile leg descending' operation on the pile legs 103A and 103D until the bottom loads of the pile legs 103A and 103D show that the stress reaches 4000t, maintaining the pressure for a period of time, observing the height of the pile leg 103 until the pile leg 103A and 103D are not changed any more and the platform is stable, and judging that the preloading of the pile legs 103A and 103D is finished.
The steps are repeated, and the pile legs 103B and 103C are pre-stressed to the bottom for bearing 4000 t. Confirming that the locking mechanisms 105 at the pile legs 103A and 103D are in a working state and are at the highest gear 6000t, adjusting the gears of the locking mechanisms 105 at the pile legs 103B and 103C in stages, wherein the difference value between the stages can be set to 500t preferentially until the stress of the locking mechanisms 105 of the pile legs 103B and 103C is 1500t, then starting the lifting mechanisms 104 at the pile legs 103B and 103C of the upper hull 101, taking the 'pile leg descending' action on the pile legs 103B and 103C until the bottom loads of the pile legs 103B and 103C show that the stress reaches 4000t, maintaining the pressure for a period of time, and judging that the preloading of the pile legs 103B and 103C is finished by observing the height of the pile legs 103 until the platform is stable and the platform is not changed any more.
After the preloading of the four legs 103 is completed, the locking mechanisms 105 of the four legs 103 of the lower floating body 102 are readjusted to be at the highest gear 6000t, and the state of the bottom-seated self-elevating platform 10 is as shown in fig. 8.
Step S70: the upper hull 101 is lifted to the working air gap.
When the inclination angle of the upper hull 101 is confirmed to be within 0.3 °, the "platform up" operation is performed on the upper hull 101 until the bottom of the upper hull 101 is separated from the water surface to the working air gap height, and the state of the submersible self-elevating platform 10 is as shown in fig. 9.
Example 2
Taking a 2500t lifting capacity sitting-bottom self-elevating platform as an example, the pile inserting method is explained in detail and comprises the following specific steps:
step S10: the platform is shifted to a designated position.
Before the platform is shifted, exploration and sea sweeping work are carried out on geology in an operation area in advance, information such as geological conditions and submarine topography of each operation place is mastered, and the operation conditions of the bottom-sitting self-elevating platform 10 are met.
The platform is moved to a corresponding construction position through a tugboat or by self, the state at the moment is as shown in figure 3, the upper hull 101 and the lower float 102 are combined into a whole, the lower float 102 and the pile leg 103 are retracted to a towing position, the gear of a locking mechanism 105 which is responsible for connecting the lower float 102 and the pile leg 103 is set to be a highest gear 6000t, and the platform is ensured to be positioned at a designated position by adopting a dynamic positioning or anchoring positioning mode.
Step S20: pre-extending legs 103.
According to the geological conditions of the operation place, before the floating body 102 is put down, the four pile legs 103 need to be pre-extended for a distance of 5m in advance, when the bottom of the lower floating body 102 is located on the seabed, the pre-extended pile legs 103 can realize the function of rapid pile inserting and positioning, the platform is prevented from sliding under the influence of environmental loads such as stormy waves and currents, and the safety of the platform is ensured.
According to the needs of sinking and floating stability, before the pile legs 103 are pre-extended, a proper amount of ballast water needs to be injected into the lower floating body 102 so as to reduce the height of the center of gravity of the platform and prevent the platform from overturning in the sinking and floating process of the lower floating body 102.
The net buoyancy of the lower floating body 102 is upward, the obtained pressure load water amount of the lower floating body is monitored through the monitoring mechanism 106, the net buoyancy of the lower floating body is 8000t through integrating the water displacement of the lower floating body and the dead weight, the locking mechanism 105 which is responsible for connecting the lower floating body 102 and the pile leg 103 is fixedly arranged on the upper surface of the lower floating body 102 and always bears upward counter force 2000t, and the pile leg 103 can be pre-stretched in a diagonal processing mode.
For ease of description, the four legs 103 are labeled 103A, 103B, 103C, 103D differently, as shown in fig. 2. Before the pile legs 103 are pre-extended, the platform is adjusted to be basically horizontal, the horizontal inclination angle of the upper hull 101 is optimally ensured to be within 0.3 degrees, the locking mechanisms 105 at the pile legs 103A and 103D are opened, at the moment, the locking mechanisms 105 at the pile legs 103A and 103D are in a non-working state, the locking mechanisms 105 at the pile legs 103B and 103C are in a working state, then the lifting mechanisms 104 at the pile legs 103A and 103D of the upper hull 101 are started, and the pile legs 103A and 103D are operated to be in a 'pile leg descending' mode until the pile legs 103A and 103D are reduced by 5m +/-0.5 m compared with the initial height.
And repeating the steps, opening the locking mechanisms 105 at the pile legs 103B and 103C, enabling the locking mechanisms 105 at the pile legs 103B and 103C to be in a non-working state, enabling the locking mechanisms 105 at the pile legs 103A and 103D to be in a working state, starting the lifting mechanisms 104 at the pile legs 103B and 103C of the upper hull 101, and performing 'pile leg descending' operation on the pile legs 103B and 103C until the pile legs 103B and 103C are reduced by 5m +/-0.5 m from the initial height. At this point, the pre-extension leg 103 action is complete, as shown in fig. 4.
Step S30: the floating body 102 is lowered to the seabed.
Before the floating body 102 is put down, the horizontal inclination angles of the upper ship body 101 and the lower floating body 102 are monitored through an inclination angle monitoring mechanism, when the inclination angles of the upper ship body 101 and the lower floating body 102 are larger than a preset angle of 0.3 degrees, the inclination angles of the upper ship body 101 and the lower floating body 102 can be adjusted by adjusting ballast water in the upper ship body 101, and the same inclination angles of the upper ship body 101 and the lower floating body 102 and the preset angle of not larger than 0.3 degrees are ensured so as to ensure that a platform is stable; it is confirmed that the locking mechanisms 105 of all four legs 103 are at the highest 6000 tonne setting.
The lifting mechanisms 104 at the four pile legs 103 of the upper hull 101 are started simultaneously, and the 'pile leg descending' action is taken, so that the floating body 102 must be synchronously put down at the same time, and the phenomenon that the pile legs 103 and the lower floating body 102 are blocked due to the fact that the putting speeds are inconsistent is avoided.
Continuing to lower the floating body 102 until the pile legs 103 touch the bottom seabed, closely paying attention to the lowering height of the pile legs 103, prejudging the bottom touching state of the pile legs 103 according to water depth data monitored by the depth monitoring mechanism in real time, and judging the sequence of the mud entering of the pile legs 103 by observing draft display at four corners of the upper hull 101, such as that the draught of a left side of a bow part is reduced, the pile legs 103A touch the bottom, the draught of a right side of a stern part is reduced, the pile legs 103D are also touched, and the like until all four pile legs 103 are in mud and the lower floating body 102 is located on the seabed; in the process, the inclination angle of the platform is required to be always kept within 0.3 degrees. At this time, the state of the submersible jack-up platform 10 is as shown in fig. 5.
Step S40: the upper hull 101 is lifted out of the water.
After the lower float 102 is seated on the seabed, the gear of the locking mechanism 105 on the four legs 103 is still set to 6000 t. Confirming that the inclination angle of the upper hull 101 is within 0.3 degrees, the loading of each lifting mechanism 104 of the upper hull 101 is within a rated lifting range, and reserving enough internal circulation ballast water in a ballast tank of the upper hull 101 for the lifting process. And simultaneously starting the lifting mechanisms 104 at the four pile legs 103 of the upper hull 101 to lift the upper hull 101 away from the water surface, wherein in the process, the stress of the locking mechanism 105 at a single pile leg 103 is 5500t, and the loads of the upper hull 101 and the pile legs 103 are transmitted to the lower hull 102 through the locking mechanism 105, so that the mud entering depth of the lower hull 102 is continuously increased, and the mud entering depth can be monitored in real time through the depth monitoring mechanism.
After the upper hull 101 is lifted until the bottom plate of the vessel leaves the water surface, the air gap height is maintained at 0.5m +/-0.1 m, and the small air gap height is set to mainly prevent the risk of platform inclination caused by uncompacted foundation during pile insertion. The completed squat bottom jack-up platform 10 is shown in figure 6.
Step S50: the lower float 102 is pre-loaded to a target load. (with integral preloading)
In order to ensure the working safety of the platform, the foundation at the bottom of the lower floating body 102 and the foundation at the bottom of the pile leg 103 need to be compacted, according to the calculation result of the support reaction force in this example, a single pile leg 103 needs to be preloaded to a support reaction value of 10000t, the bearing ratio of the locking mechanism 105 to the bottom end of the pile leg 103 is set to 6: 4, the locking mechanism 105 at each pile leg 103 and the lower floating body 102 connected with the locking mechanism need to be preloaded to 6000t, and the bottom of the pile leg 103 needs to be preloaded to 4000 t. The preloading of the whole platform is divided into two steps of preloading of the lower floating body 102 and preloading of the pile legs 103.
The stress of the locking mechanisms 105 at the four pile legs 103 is 5500t, and the stress of the lifting mechanism 104 of the upper hull 101 is 4500 t.
The preloading of the lower floating body 102 can be realized in an integral preloading mode, sufficient ballast water can be injected into the upper ship body 101, so that the locking mechanisms 105 at the pile legs 103A, 103B, 103C and 103D simultaneously reach a preloading target value of 6000t, after the pressure is maintained for a period of time, the preloading of the lower floating body 102 is judged to be finished by observing the mud penetration depth of the lower floating body 102 until the mud penetration depth of the lower floating body 102 is not changed any more.
After the pre-loading of the lower floating body 102 is completed, the height of the air gap of the upper hull 101 is continuously adjusted to 0.5m ± 0.1m, and the state of the bottom-mounted self-elevating platform 10 is shown in fig. 7.
Step S60: pre-loading the legs 103 to the target load.
Preloading is carried out on the pile legs 103 in a diagonal preloading mode, the load setting of the locking mechanisms 105 at the two diagonal pile legs 103 is adjusted, and the two pile legs 103 are operated in a 'pile leg descending' mode, so that redundant vertical load is transmitted to the bottoms of the pile legs 103.
Preloading pile legs 103A, 103D to bottom load 4000 t: confirming that the locking mechanisms 105 at the spud legs 103B and 103C are in the working state and at the highest gear 6000 t; the gears of the locking mechanisms 105 at the pile legs 103A and 103D are adjusted in a grading manner, the difference value between each grade can be set to be 500t better until the stress of the locking mechanisms 105 of the pile legs 103A and 103D is 1500 t; and then starting the lifting mechanisms 104 at the pile legs 103A and 103D of the upper hull 101, performing 'pile leg descending' operation on the pile legs 103A and 103D until the bottom loads of the pile legs 103A and 103D show that the stress reaches 4000t, maintaining the pressure for a period of time, observing the height of the pile leg 103 until the pile leg 103A and 103D are not changed any more and the platform is stable, and judging that the preloading of the pile legs 103A and 103D is finished.
The steps are repeated, and the pile legs 103B and 103C are pre-stressed to the bottom for bearing 4000 t. Confirming that the locking mechanisms 105 at the pile legs 103A and 103D are in a working state and are at the highest gear 6000t, adjusting the gears of the locking mechanisms 105 at the pile legs 103B and 103C in stages, wherein the difference value between the stages can be set to 500t preferentially until the stress of the locking mechanisms 105 of the pile legs 103B and 103C is 1500t, then starting the lifting mechanisms 104 at the pile legs 103B and 103C of the upper hull 101, taking the 'pile leg descending' action on the pile legs 103B and 103C until the bottom loads of the pile legs 103B and 103C show that the stress reaches 4000t, maintaining the pressure for a period of time, and judging that the preloading of the pile legs 103B and 103C is finished by observing the height of the pile legs 103 until the platform is stable and the platform is not changed any more.
After the preloading of the four legs 103 is completed, the locking mechanisms 105 of the four legs 103 of the lower floating body 102 are readjusted to be at the highest gear 6000t, and the state of the bottom-seated self-elevating platform 10 is as shown in fig. 8.
Step S70: the upper hull 101 is lifted to the working air gap.
When the inclination angle of the upper hull 101 is confirmed to be within 0.3 °, the "platform up" operation is performed on the upper hull 101 until the bottom of the upper hull 101 is separated from the water surface to the working air gap height, and the state of the submersible self-elevating platform 10 is as shown in fig. 9.
In the submersible jack-up platform 10 according to embodiments 1 and 2, the monitoring mechanism 106 can monitor the states of the upper hull 101, the lower hull 102, the legs 103, the lifting mechanism 104, and the locking mechanism 105 during the pile inserting process, and the submersible jack-up platform 10 controls the movement of the upper hull 101, the lower hull 102, and the legs 103 through the lifting mechanism 104 and the locking mechanism 105 according to the specific conditions of the components.
In the invention, the self-elevating platform with the bottom and the pile inserting method are provided, the self-elevating platform with the bottom is provided with an upper ship body and a lower floating body which are connected through pile legs, and the upper ship body and the lower floating body can be opened and closed through a lifting mechanism and a locking mechanism arranged on the self-elevating platform; during construction operation, the lower floating body with the pile legs extending out of the lower floating body is inserted into a seabed, the upper ship body is lifted to leave the water surface, surging invasion can be avoided, in addition, the lower floating body provides huge buoyancy and a bottom sitting area, the lower floating body and the pile legs inserted into the seabed share the vertical load and the bending moment brought by the upper ship body, and the device is suitable for softer geology; in the pile inserting process, the lower floating body bears most of load all the time, and the risk of platform inclination caused by sudden settlement of a certain pile leg can be avoided. In addition, the lower floating body and the pile legs are fixedly connected under the set load, the load bearing capacity of the lower floating body and the pile legs can be adjusted in a grading mode, so that the load distribution between the lower floating body and the pile legs is realized, when the vertical load is smaller than a set value, the load is borne by the lower floating body, when the vertical load exceeds the set value, the redundant load is borne by the bottoms of the pile legs, and the mode that the lower floating body and the pile legs bear the load together and the load is adjustable is the core idea of the invention.
Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (20)

1. A self-elevating platform with a bottom, which comprises an upper hull, pile legs and a lower floating body, and is characterized in that the platform also comprises a lifting mechanism and a locking mechanism,
the pile legs penetrate through the upper hull and the lower floating body;
the lifting mechanism is arranged on the upper ship body to realize the relative motion of the pile legs and the upper ship body;
the locking mechanism is arranged on the lower floating body to realize that the pile leg and the lower floating body are relatively static;
the platform floats, the upper ship body floats on the water surface, the pile legs are retracted, the lower floating body is retracted to the bottom of the upper ship body, and the lower floating body is positioned below the water surface;
the platform stands, the pile legs extend out of the lower floating body, the lower floating body sinks to the seabed, and the pile legs are inserted into the seabed to fix the lower floating body; the upper hull is lifted by the spud legs and is separated from the water surface.
2. The platform of claim 1, wherein the locking mechanism has a detent position no higher than 6000 t.
3. The platform of claim 1, wherein the lower hull is filled or drained of ballast water to adjust the lower hull center of gravity.
4. The platform of claim 1, wherein four of the legs are symmetrically disposed on the upper hull and the lower hull.
5. The platform of claim 1, wherein the platform is provided with a monitoring mechanism.
6. A method of piling a submersible jack-up platform using the platform of any one of claims 1 to 5, comprising the steps of:
step S10: the platform is shifted to a designated position;
step S20: pre-extending pile legs;
step S30: the floating body is put down to the seabed;
step S40: lifting the upper hull away from the water;
step S50: preloading the lower floating body to a target load;
step S60: pre-loading the pile leg to a target load;
step S70: the upper hull is raised to the working air gap.
7. The method of claim 6, wherein in step S10, the lower buoyant body is retracted to the bottom of the upper hull before the platform is displaced.
8. The method of claim 6, wherein in step S20, when the legs are pre-extended, the locking mechanisms of two legs on one diagonal of the platform are in operation, and a "leg-lowering" operation is performed on the two legs on the other diagonal to pre-extend the two legs by a predetermined distance; and repeating the steps to complete the pre-stretching of the residual pile legs.
9. A method of piling as claimed in claim 8 wherein ballast water is injected into the lower buoyant body to lower the platform centre of gravity before the legs are pre-extended.
10. The method of claim 8, wherein said predetermined distance is 5m ± 0.5 m.
11. The pile inserting method according to claim 6, wherein in the step S30, the locking mechanism is adjusted to the working state; the operation of pile leg descending is adopted, and simultaneously the lower floating body is put down to the seabed.
12. The method of claim 6, wherein said step S40 is performed by taking a "platform up" action on the upper hull to lift the upper hull off the water to a predetermined air gap height.
13. The method of claim 12, wherein said predetermined air gap height is 0.5m ± 0.1 m.
14. The pile inserting method according to claim 6, wherein in step S50, a diagonal preloading operation is adopted to adjust the locking mechanisms of two legs on one diagonal of the platform to an operating state, and a "leg raising" operation is adopted to two legs on the other diagonal until the floating body reaches a target load under the preloaded diagonal, and the pressure is maintained for a period of time until the platform is stable; and repeating the steps to finish the pre-loading of the floating body under the rest diagonal.
15. The pile inserting method according to claim 6, wherein in step S50, an integral preloading operation is performed to bring the lower hull to a target load by injecting ballast water into the upper hull, and the pressure is maintained for a period of time until the platform is stabilized.
16. The pile inserting method according to claim 6, wherein in step S60, a diagonal pre-load operation is performed to adjust the two leg locking mechanisms on one diagonal of the platform to the highest gear, and after adjusting the locking mechanisms on the two legs on the other diagonal to a predetermined gear, a "leg down" operation is performed until the bottom of the pre-loaded leg reaches a target load, and the pressure is maintained for a period of time until the platform is stable; and repeating the steps to finish the pre-loading of the rest pile legs.
17. The method of claim 6, wherein in step S60, the load condition at the bottom of the leg is monitored in real time by a monitoring mechanism.
18. The method of claim 6, wherein said step S70 is performed by taking a "platform up" action on the upper hull to lift the upper hull to the working air gap.
19. The pile inserting method according to claim 6, wherein in the steps S20, S30 and S40, an inclination angle of the platform is monitored in real time by a monitoring mechanism, and when the inclination angle is greater than a predetermined angle, the inclination angle is adjusted by adjusting ballast water in the upper hull.
20. The method of claim 19, wherein said predetermined angle is 0.3 °.
CN202010173500.0A 2020-03-13 2020-03-13 Bottom-sitting self-elevating platform and pile inserting method Pending CN111236197A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114802599A (en) * 2022-05-18 2022-07-29 华电重工股份有限公司 Fixing system and fixing method for bottom-sitting ship
CN115012379A (en) * 2022-06-16 2022-09-06 中国能源建设集团广东省电力设计研究院有限公司 Self-installation and reinforcement method for offshore converter station platform
CN115094890A (en) * 2022-07-18 2022-09-23 中交第一航务工程局有限公司 Construction method for semi-floating pile inserting of self-elevating platform type leveling ship

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114802599A (en) * 2022-05-18 2022-07-29 华电重工股份有限公司 Fixing system and fixing method for bottom-sitting ship
CN115012379A (en) * 2022-06-16 2022-09-06 中国能源建设集团广东省电力设计研究院有限公司 Self-installation and reinforcement method for offshore converter station platform
CN115012379B (en) * 2022-06-16 2024-04-19 中国能源建设集团广东省电力设计研究院有限公司 Self-installation and reinforcement method for offshore converter station platform
CN115094890A (en) * 2022-07-18 2022-09-23 中交第一航务工程局有限公司 Construction method for semi-floating pile inserting of self-elevating platform type leveling ship
CN115094890B (en) * 2022-07-18 2024-01-30 中交第一航务工程局有限公司 Semi-floating pile inserting construction method for self-elevating platform type leveling ship

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