RU2689471C1 - Method of fixation of tubular steel piles in support base of marine stationary hydraulic structures (platforms), and also device for its implementation - Google Patents

Abstract

FIELD: construction.SUBSTANCE: invention relates to construction of offshore structures, specifically to the technology of mounting pipe steel piles in a support base of offshore stationary structures (platforms). Disclosed is a method of mounting pipe piles in a support base of offshore stationary structures, wherein installing a support base of an offshore structure on the sea bottom, pipe piles are hammered through guides of support base sleeves to the sea bottom; device equipped with hydraulic jacks is lowered inside pile so that straps of hydraulic jacks are arranged in the middle of inner circular groove in guide sleeve; pressure is created in hydraulic system of jacks, at the same time rods pushing inner surface of pile till pressure reaches value at which voltage in body of pipe pile reaches yield point of pile material; thus performing deformation of pile body into inner circular groove of guide sleeve; at the end of deformation process pressure in hydraulic system of jacks is dropped, rods together with straps return into initial position, device lifting is performed, at that control over pile material expansion process is controlled by pressure change in hydraulic system of hydraulic jacks. Invention covers also the device for attachment of pipe piles in support base of offshore structures.EFFECT: improving reliability of piles fastening in guide shells of support base and reduction of labor costs.5 cl, 4 dwg

Description

The invention relates to the construction of offshore structures, in particular to the technology of fastening steel pipe piles in the support base of offshore fixed structures (platforms).

A known method of fastening the pile to the rack of the support block of the offshore stationary platform and device for its execution according to the author's certificate SU1231128 dated 05/15/1986, which, in order to increase reliability and reduce costs when mounting the pile to the rack of the support block by cementing, provides for the displacement of sea water from the air an annular gap between the pile and the support block, supplying it with the estimated amount of a mixture of fresh water with crushed heat-insulating material, cooling the water until an ice block is formed . After this, the gap is cemented. Water is cooled during the entire cementing process. The device includes a camera with a heat insulator mounted on its outer surface facing the rack. Inside the chamber around the pile is placed a coil connected by pipeline to the cold unit. The ice block closes the annular gap and serves as a formwork for its cementation.

The disadvantage of this method of fastening the pile to the rack of the supporting block of the offshore stationary platform, as well as all other methods of fastening the pile to the support base by pumping cement mortar into the annular space between the pile and the stand (guide sleeve), is the dynamic strength of the cement-steel contact zone and alternating loads, due to the separate work of the pile and stand, and, consequently, the deterioration of the reliability of the structure as a whole. In addition, cementing each pile requires a lot of labor and time for cement hardening, which is especially critical when installing an offshore platform in Arctic waters with a short navigation period.

The closest to the proposed solution is a method of fastening steel pipe piles in the guide sleeves of the support base by hydraulic opening of the section / pile sections into internal circular grooves in the guide sleeve under the pressure of water supplied to the inside of the isolated pile section (US patent 4501514 of 02.26.1985). Insulation (sealing) of the selected area, ensuring the supply of water and creating the necessary pressure is carried out by means of a device, which is lowered inside the pile, at the ends of which inflatable flexible sealing elements are installed.

The main disadvantage of this method is associated with a device for hydraulic release, which is difficult to manufacture, and is only suitable for one specific pile size and guide sleeve. In addition, the replacement of inflatable flexible sealing elements in field conditions is time consuming, which ultimately increases the cost of the entire process of attaching piles to the supporting base of offshore fixed structures (platforms).

The objective of the claimed invention is to create a device and method of fastening pipe piles in the support base of offshore stationary structures with the elimination of the above disadvantages.

The technical result of the claimed invention is to improve the reliability of mounting the piles in the guide sleeves of the support base through the use of a simple design and manufacture of a device equipped with hydraulic jacks, providing unclamping the pile only in the area of the internal circular grooves of the guide sleeves, as well as reducing labor costs and cheaper work.

The technical result is achieved due to the fact that the method of mounting pipe piles in the support base of offshore stationary structures, in which the support base of the marine structure is installed on the seabed, pipe tubes are driven through the guide sleeves of the support base into the bottom of the sea. , equipped with hydraulic jacks, to such a depth that the lining of the rods of hydraulic jacks located in the middle of the inner circular groove in the guide sleeve; create pressure in the hydraulic system of jacks, while the rods through the pads pressure on the inner surface of the pile until the pressure reaches the value at which the stress in the body of the pipe pile reaches the yield strength of the pile material; thus, the body of the pile is deformed into the internal circular groove of the guide sleeve; at the end of the deformation process, the pressure in the hydraulic system of the jacks is released, the rods together with the plates return to their original position, and the device is lifted.

In this case, the control over the process of unclamping the material of the pile is carried out by changing the pressure in the hydraulic system of the hydraulic jacks.

In this case, the inner surface of the guide sleeve has more than one internal circular groove.

Also, the technical result is achieved due to the fact that the device for fastening pipe piles in the supporting base of offshore stationary structures includes a housing and is characterized in that it contains at least three hydraulic jacks, the rods of which can move in radial directions relative to the pile axis, on stock pads are located.

In addition, the device is made in the form of at least a triangular prism or cylinder.

In this case, applied spring or hydraulic return rod to its original position.

In this case, the fastening of hydraulic jacks on the body is carried out in the landing slots or on the outer bearing flange.

In addition, the device case in the lower and / or upper part has a thread for attaching a spherical or conical shoe guide, or the case for the second device, or for attaching a pipe or cable for lowering the device inside the pile.

The device may also include a hydraulic station included in the hydraulic system of hydraulic jacks, equipped with a remote control.

The essence of the proposed method is illustrated by drawings:

FIG. 1 - Sequence of processes occurring during unclenching of the pile by the device in the guide sleeve;

FIG. 2 - Scheme of fastening the pile in the guide sleeve of the support base using hydraulic jacks;

FIG. 3 - Diagram of the device equipped with hydraulic jacks mounted on the body, made in the form of a hexagonal prism;

FIG. 4 is a diagram of a device equipped with hydraulic jacks connected in a ring structure,

Where:

1 - pile;

2 - guide sleeve;

3 - the case of the device for unclamping the pile;

4 - overlays of rods of hydraulic jacks;

5 - internal groove of the guide sleeve;

6 - hydraulic jack system;

7 - hydraulic jack;

8 - hydraulic jack rod;

9 - technological channels in the housing of the device for unclamping the pile;

10 - pipe;

11 - landing jacks for jacks;

12 - nipple thread of the device;

13 - device body coupling;

14 — spherical shoe of unclamping pile;

15, 16 — high pressure hoses for supplying hydraulic fluid to the hydraulic system of jacks for extending the rods;

17, 18 - high pressure hoses for supplying hydraulic fluid to the hydraulic system of jacks for returning the rods;

19 - connecting earrings;

20 - bolted connection for connecting hydraulic jacks in an annular structure on the device body;

21 - fitting for connecting the high pressure hose to the hydraulic system of the jack to return the rod;

22 - fitting for connecting a high pressure hose to the hydraulic system of the jack for the extension of the rod;

23 - covers.

The method of fastening steel pipe piles in the support base of marine fixed structures (platforms) using devices equipped with jacks, includes the following operations:

1. Installation of the support base of the offshore structure on the seabed.

2. Blockage of steel pipe piles (1) through the guide sleeves (2) of the support base to the bottom of the sea.

3. Descent inside the pile of the device (3), equipped with hydraulic jacks (7), to such a depth that the plates (4) of the rods (8) of hydraulic jacks (7) are located in the middle of the inner circumferential groove (5) in the guide sleeve (2).

4. Creating pressure in the hydraulic system (6) jacks (7). In this case (see Fig. 1), the rods (8) through the pads (4) press on the inner surface of the pile (1) and when the pressure reaches the value at which the stress in the pipe body reaches the yield strength of the pile material (1), plastic deformation begins (uncoupling) the pile body (1) into the internal circular groove (5) of the guide sleeve (2), while eliminating the need for isolation (sealing) of the internal pile section under consideration.

Control over the expansion process (plastic deformation) of the pile material (1) is carried out by changing the pressure in the hydraulic system (6) of the hydraulic jacks (7). The sharp increase in pressure in the hydraulic system of jacks suggests that the outer surface of the pile (1) came into contact with the inner surface of the inner circular groove (5) of the guide sleeve (2).

The process of unclamping the pile is over.

5. The pressure in the hydraulic system (6) of the jacks (7) is released, the rods (8) together with the linings are returned to the transport position by means of springs, or the hydraulic system in the case of using jacks with hydraulic stem return.

6. Lifting the device. The process of fastening the pile in the guide sleeve of the support base is completed.

When fastening tubular steel piles (1) in the guide sleeves (2) of the supporting base of marine fixed structures (platforms), a device is used that has a housing and is equipped with hydraulic jacks (7), the rods (8) of which can move in radial directions relative to the axis piles (1) and guide sleeve (2). When creating pressure in the hydraulic system (6) of the jacks (7), the rods (8) of the hydraulic cylinders press the inner surface of the pile (1) through the pads (4) and under pressure exceeding the yield strength of the pile material, plastic deformation (expansion) of the pile body begins (1 ) into the internal circular groove (5) of the guide sleeve (2).

For a better understanding of the present invention and demonstration of the possibility of using various mounting options for hydraulic jacks on the body of devices used for fastening piles in guide sleeves of the supporting base of marine fixed structures, FIG. 2, 3, 4.

According to the presented figures, the number of hydraulic jacks (7) in the device can be from three or more depending on the geometrical parameters (internal diameter, wall thickness) and the physicomechanical properties of the pile material (1), as well as the geometrical parameters (configuration, height, diameter of the housing and technical characteristics (force developed by the jack, the stroke, the method of returning the stem) of the hydraulic jack (7).

According to the presented fig., The steel case (3) of the device depending on the number and method of fastening the hydraulic jacks

(7) may have:

- a cylindrical shape (see Fig. 2) with both technological channels (9) for laying high-pressure hoses and their external arrangement (see Fig. 4);

- the shape of a polygonal (three-four-five-hexagonal or more) prism (see Fig. 3 - a body in the form of a hexagonal prism).

The device case in the upper and lower parts must be threaded (nipple or coupling) to connect the bottom of the guide spherical (14) or conical shoe, or the second case with installed hydraulic jacks, if necessary, unclean the pile in two depth places (if there are several circular grooves on the inner surface of the guide sleeve), for attaching the top of the pipe or cable for lowering the inside of the pile.

According to the presented Fig., Can be used various mounting options hydraulic jacks on the device, for example:

• in the landing slots 11 (see Fig. 2), securing the jacks with the help of covers 23;

• outside, connecting hydraulic jacks in a ring construction and placing them on the bearing flange (see Fig. 3-4).

Claims (5)

1. The method of mounting pipe piles in the support base of offshore fixed structures, in which the support base of the offshore structure is installed on the seabed, pipe piles are driven through the guide sleeves of the support base into the sea bottom, characterized in that a device equipped with hydraulic jacks is pushed into the pile such depth that the lining of the hydraulic jacks rods are located in the middle of the inner circular groove in the guide sleeve, create pressure in the hydraulic system of the jacks, while the rods through the pads, pressure is applied to the internal surface of the pile until the pressure reaches the value at which the stress in the body of the pipe pile reaches the yield strength of the pile material, thus the body of the pile is deformed into the internal circular groove of the guide sleeve, after the deformation process, the pressure in the hydraulic system of the jacks is released; with the lining returning to their original position, lifting the device, while monitoring the process of unclamping the pile material is carried out by changing the pressure in the hydraulic system of hydraulic jacks. 2. The method according to p. 1, characterized in that the inner surface of the guide sleeve has more than one inner circular groove. 3. Device for mounting pipe piles in the support base of marine fixed structures, comprising a housing, characterized in that it contains at least three hydraulic jacks, the rods of which can move in radial directions relative to the pile axis, while the pads are located on the rods This applies a spring or hydraulic return of the rod to its original position, the fastening of the hydraulic jacks on the body is carried out in the mounting slots or on the outer bearing flange, and the device body in the bottom minutes and / or upper part is threaded for the connection of a spherical or conical guide shoe or casing of the second device, or for connection to a pipe or a cable descent device inside the pile. 4. The device according to p. 3, characterized in that the casing of the device is made in the form of at least a triangular prism or cylinder. 5. The device according to p. 3, characterized in that it includes a hydraulic station included in the hydraulic system of hydraulic jacks, equipped with a remote control.

Images