WO2008037963A1

WO2008037963A1 - Improvements in and relating to pile or column installation

Info

Publication number: WO2008037963A1
Application number: PCT/GB2007/003575
Authority: WO
Inventors: Neil Maxwell Williams
Original assignee: Fugro Seacore Limited
Priority date: 2006-09-26
Filing date: 2007-09-24
Publication date: 2008-04-03
Also published as: GB0718546D0; GB0618885D0; GB2442323A

Abstract

An installation for handling a pile or column (14) for its erection at a predetermined location from the bed (SB) of a volume of water, including means (3) for locating the pile or column at said predetermined location, gripper/support means/units (11, 12) for physically engaging with the pile or column (14) at a position offset from the region (17) of the centre of gravity of the pile or column whilst the pile or column is floating in the water, and means for enabling the pipe or column to tilt to a required orientation with respect to the said bed (SB).

Description

IMPROVEMENTS IN AND RELATING TO PILE OR COLUMN

INSTALLATION

This invention relates to the handling of foundation piles and similar columns.

In particular, the present invention is concerned with the handling of relatively large diameter and lengthy foundation piles and similar columns .

In particular the present invention is concerned with the installation of piles having lengths of, for example, fifty metres and diameters of several metres.

In further particular the present invention is concerned with the erection of such piles and columns in a marine, esturial, river,, lake, or other water environment.

In practice, the installation of piles in such water environments involves problems and difficulties stemming from the very nature of the locations into which the piles or columns are required to be placed.

For example, in a marine environment there are not only the problems arising from the actual handling of the pile or column, for example, when positioning a lengthy and large diameter pile or column in an upright position but additionally further difficulties arise as a result of tidal flows in terms of water velocity and tidal water level variations at the location at which it is required to position the pile or column..

It is an object of the present invention to provide methods of and means for erecting piles of the kind herein mentioned in the bed of the water in which it is located. Hereinafter whatever the form of the water the bed thereof will be referred to as the sea bed.. Broadly according to a first aspect of the invention there is provided a method of erecting a pile or column at a required inclination in the bed of a volume of water, including the steps of arranging the pile or column to be floatable in water, moving the pile or column when floating to a location at which it is required to be erected, holding the floating pile or column against displacement from the location, and tilting the pile or column from a horizontal floating position to the required angular positioning with respect to the vertical, and setting the pile or column in the bed of the water at said location.

According to a further aspect of the invention there is provided a method of erecting a a pile or column or other column in the sea bed , including the steps of, rendering the pile or column floatable in the water, displacing the pile or column whilst floating to the location at which it is desired to erect the pile or column, supporting/gripping the pile or column at a position offset from the region of the centre of gravity of the pile or column, exerting lift upon the pile or column at the offset position whilst enabling the pile or column to tilt under the action of gravity during said lifting to its required setting with respect to the seabed.

Conveniently, during said tilting of the pile or column, water is enabled to enter into the pile or column so as to enhance the rate of tilt.

In accordance with a further aspect of the invention there is provided an installation for handling a pile or column for its erection at a predetermined location from the bed of a volume of water, including means for locating the pile or column at said predetermined location, means for physically engaging with the pile or column whilst it is floating in the water at a position offset from the region of the centre of gravity of the pile or column, and means for enabling the pipe or column to tilt to a required orientation with respect to the said bed,. Preferably, the means for locating the pile or column includes support elements for mounting means for gripping/supporting the pile of column at a position offset from the centre of gravity thereof, and means for enabling the pile or column to tilt to its required orientation whilst being gripped by the gripping means.

In particular the support elements are elongate and are mounted from a support vessel or the like in such manner that the they may be displaced with respect to the support vessel such that the lower ends thereof may bear against the bed of the volume of water, and wherein means are provided to allow the gripping means to displace relative to the support elements to facilitate tilting of the pile or column upwardly to a required orientation with respect to the bed

In a preferred construction the means for gripping/supporting the pile or column includes a trough like formation into which a selected length of the pile or column is nestable whilst floating, and including closure means serving to co-operate with that part of the pile or column that is immediately opposite to the region thereof thereof engaged by the trough like formation in such manner that the pile or column is firmly gripped.

Preferably the installation includes a second means for gripping/supporting the pile or column when in its required orientation at a location spaced above or below the position of the first mentioned means for supporting/gripping the pile or column, the arrangement being such that when the pile or column has been set to its required orientation the second gripping/supporting means adapted to exert further grip on the pile or column to enable the pile or column to be displaced to such extent that its lower end can engage with the bed of the water, whilst being supported by the means/units at two spaced apart locations lengthways of the pile or col -A-

Preferably both said gripping/support means are mounted from the support elements, the latter being located at opposite sides of a moon pool formation in a vessel and of such length the their lower ends are contactable with the bed of the volume of water, there being means for enabling the simultaneous displacement of the gripping/supporting means lengthways of the members to lower the pile or column so that the lower end thereof is contactable with the bed of the volume of water.

Preferably, both said gripping/support means are mounted from upright members located at opposite sides of a moon pool formation in a vessel, the members being of such length the their lower ends are contactable with the seabed, there being means for enabling the simultaneous displacement of the gripping means/means/units lengthways of the members to lower the pile or column so that the lower end thereof is contactable with the seabed.

For a better understanding of the invention and to show how to carry the same into effect reference will now be made to the accompanying drawings in which:-

Figure 1 very schematically illustrates inter-alia; an installation for use in positioning a pile or column into an upstanding position in/from a sea or other water bed,

Figure 2 illustrates a first stage in the positioning of a pile or column for setting in an upright position in the sea or other water bed;

Figures 3 to 6 schematically illustrate successive further stages involved in positioning and erecting a pile or column into an upstanding setting,

Figure 7 schematically illustrates the installation from a direction transverse to that of the previous Figures, Figure 8, schematically illustrates the stage by stage tilting of the pile or column;

Figure 9 illustrates in more detail the construction of a gripper/support means/unit;

Figures 10 to 12, schematically illustrate successive stages of the engagement of a gripper/support means/unit with the pile or column only a schematic representation of supports for the means/nits being shown; and

Figure 13 is a side view of a pipe/column which gripped by a gripper/support means/unit.

Referring now to Figures 1 to 7 in which a working platform assembly 1 includes a working deck 2. As shown this marine working platform assembly 1 comprises a so called jack-up barge 3 that is floatable for transportation between locations of intended use in the manner of a barge that can be self propellable or otherwise manoeuvred .

The working deck 2 of the barge 3 includes a so-called moon pool 4 (Figure 7). This pool can be located internally of the barge 3 or at one end thereof so that it opens out directly to the water.. With this arrangement the deck 2 as very schematically illustrated in Figure 7 two spaced side by side sections 5 one to each of opposite sides of the pool 4..

The barge is provided with upright support legs 6 that are liftable relative to the barge 3 when the latter is required to travel from one location to another and are lowerable to a working positions in which these support legs 6 serve to raise the barge 3 above the sea level SL and to maintain the barge in the raised position as shown in the drawings . In the Figures the sea or other water bed is indicated at SB. The jack-up barge 3 is provided at one end region thereof in co-operation with the moon pool 4 and the side sections/decks 5 with a load lifting arrangement 7 (to be discussed in greater detail hereinafter) which is positionable as shown in Figures 1 to 8 in an upright position when required for the handling of loads, and which is retractable to a stowed horizontal position (not shown) whilst the barge is moving.

This load lifting arrangement 7 includes two side by side main support elements 8,9 respectively mounted one from each of said deck sections 5. and a support frame 10 that bridges the spaced deck sections 5 and thus the moon pool 4. As will be seen from Figures 1 to 7,. these support elements 8,9 when upright extend below the barge 3 to bear upon the seabed, and project upwards above the level of the raised barge 3. The construction of the support frame is such as to bridge the space between the deck sections 5 and incorporates arrangements whereby the load lifting arrangement can be moved to a generally horizontal stowed position (not shown) during displacement of the barge 3.

The support frame mounts upper and lower pipe gripper/support means/units 11,12 respectively that bridge the support elements 8 and 9 The means/units are lengthways displaceable of the support elements 8 and 9 by any convenient means such as by being under the control of hydraulic motor drives. In Figure 7 a rack and pinion system 13 is very schematically indicated..

Each gripper/support means/unit 1 1,12 is of such construction as to have an open setting in which the unit can be engaged with a pile or column 14, and a closed setting in which each gripper/support means/unit 11/12 can be caused firmly to grip with the pile or column 14 in such manner that once in the closed setting displacement of the gripper/support means/means/units lengthways of the support elements lifts or lowers the pile or column engaged thereby . The construction of these gripper/support means/means/units 11,12 will be considered in greater detail hereinafter

The handling of a pile or column 14 into the vertical setting at a required location will now be considered in relation to Figures 1 to 7.

Referring initially to Figure 1 this Figure illustrates the jack-up barge 3 when it is raised and is supported by its support legs 6. The pile or column 14 to be erected is initially pushed or towed,, for example, by a tug or other appropriate vessel 15 to the general location of the raised jack-up barge 3 and is then pushed into the space between the deck sections 5 into the moon pool 4 by the tug or other appropriate vessel 15. or is towed by means of a winch (not shown) provided on the the working deck 2/5 of the barge 3

It should be noted that where tidal flows expected the barge 3 is positioned so that the pile or column 14 is pushed into position from the down current end of the jack-up barge. This requirement is essentially for safety reasons since if by chance the tug loses control of the pile or column 14 the latter will not hit the support legs 6 of the working platform i.e., jack-up barge.

The pile or column is advanced into working platform space/moon pool until the pile or column comes into contact with the submerged lower gripper/support arm 12.

In practice the lower gripper/support means/unit 12 is so positioned lengthways of the associated support elements 8 and 9 that the pile or column 14 is able to float just above the pile or column receiving and locating part 6 i.e.,. float into engagement with the lower gripper/support unit 12 . The extent to which the pile or column is moved over the gripper/support unit is such that the centre of gravity 17 of the pile or column is located to the left hand side (as shown in Figure 2) of the lower gripper/support unit 12 . That is the centre of gravity 17 of the pile or column is offset relative to the gripping zone (a typical offset distance being two metres). Once this position has been reached the gripper/support unit 12 is actuated to its closed setting in which it firmly clamps the pile or column 14 against movement relative to the unit 12.

The unit 12 is displaceable lengthways of the supporting supports 8 and 9 and is also table to tilt relative to the supports 8 and 9.

Once the gripper/support unit has been caused firmly to grip the pile or column 14 the unit 12 is caused to move upwards relative to the supports 8 and 9 and in so doing starts to lift the pile or column .

By reason of the offsetting of the centre of gravity 17 of the pile or column 14 relative to its location of engagement with the lower gripper/support unit 12 will commence to tilt under its own weight towards a vertical position. This is schematically illustrated in Figures 3 to 5.. In these Figures the direction of tilt is shown to be anti-clockwise.

As will also be seen from these Figures the now upper end region 18 of the pile or column 14 moves closer and closer to the upper gripper/support unit 11, the latter having been set into its open pile or column receiving setting. It is convenient to note that by the time the pile or column has reached the inclined position generally depicted by Figure 4 a controlled flooding of the pile or column can take place, so as to increase its weight beneath the barge. This is conveniently facilitated by providing suitable valves in the closures to the ends of the pile or column 14 .

By the time the pile or column has pivoted to the position shown in Figure 5 the upper gripper/support unit 11 would have been set to a position in which it is ready to act as a buffer serving to prevent the pile or column 14 from pivoting anticlockwise too far and thus through the required vertical setting.

In a particular arrangement each end of the pile or column is closed by end stopper/bung (not shown) at The end stoppers/bungs are provided with valves (not shown) to allow the ingress of water at the bottom of the pile or column 14 and the egress of air at the top of the pile or column. The valves are selectively remotely controllable to allow controlled flooding of the pile or column 14 . The stoppers/bungs are conveniently fitted into the ends of the pile or column 14 by means of friction inflatable bladders which form a watertight seal. When the pile or column 14 is in its required vertical setting and is ready for its lowering to the seabed the bladders are deflated. The top stopper/bung is conveniently removed by means of an on board crane whilst the lower stopper/bung is allowed to drop to the seabed for later retrieval by the crane or other convenient means.

It is convenient to note that the downward forces created by the weight of the pile or column 14 are transferred directly to the seabed by means of the support elements 8 and 9 thereby not compromising the stability of the working platform 2 as could well be the situation if the pile or column was being handled by use of an on-board crane.

It will be noted that during the pivoting of the pile or column 14 to its vertical position the lower gripper/support unit 12 is progressively moved upwards lengthways of the supports 8 and 9 so that at all times the bottom regions 20 of the pile or column cannot foul the seabed. SB

In other words, by the time the pile or column 14 reaches the vertical position the upper gripper/support unit 1 1 is able to be closed to its pile or column gripping setting whereby the pile or column 14 can be totally supported by the upper and lower gripper/support means/units and thus the associated load supporting arrangement above the seabed The lower end 20 of the pile or column is lowered into contact with the seabed or other water bed by simultaneously lowering the upper and lower gripper/support means/ means/units 11, 12 relative to the supports 8 and 9 until the pile or column 14 is firmly set in to the sea bed.

Once this has been achieved the gripper/support means/unit 11 and 12 can be operated to free them from engagement with the pile or column 14 and the jack-up barge 3 lowered and moved from the erected pile or column 14 to another location of use.

It is convenient to note that whilst in relation to Figures 1 to 7, the second gripper/support unit 12 is positioned below that of the second gripper/support unit i.e., the unit 11, used to steady and grip the pile or column unit 1 1 it is possible to arrange matters so that the second unit is located beneath the first gripperr/support unit 12 . This arrangement is particularly suitable for the handing of piles or columns in relatively deep water.

Referring now to Figure 8, this Figure schematically illustrates successive stages in the tilting of the pile or column 14 whilst being gripped by the lower gripper/support unit 12.

Figures 9 to 13 illustrate the construction and mode of operation of the gripper/support means/units 11 and 12.

In Figure 9 a gripper/support unit 11/12 is shown therein as an end view when in its horizontal setting for receiving a pile or column As will be noted the unit includes a generally semicircular main section 21 and two curved side panels 22 that pivotally connected to the free edges 23 of the main section 21. The side panels are selectively displaceable between the position shown in Figure 7 to a closed position in which they form with the main section a closed cylindrical formation. When in the closed setting the side panels are lockable in their closed positions by locking arrangements 24 . The positioning of the side panels can conveniently be effected by hydraulic rams 25.

As has been mentioned the means/means/units 11, 12 are displaceable as required lengthways of the associated supports using the latter as guide means.

Referring now to Figures 10 to 12, Figure 10 illustrates a operational position in which the pile or column 14 is positioned immediately above a gripper/support unit so that the pile or column is located immediately above the trough like main section 21. Once this position has been reached and the required centre of gravity offsetting has been set the associated means/unit 11 is raised so that the pile or column nests into the main section. This part nesting position is illustrated in Figure 11.

Figure 13 illustrates the operational position when the pile or column has been fully nested and the side panels 22 have been moved to their closed and locked positions whereby the pile or column 14 is firmly gripped by the means/unit.

Claims

1. A method of erecting a pile or column at a required inclination in the bed of a volume of water, characterised by the the steps of arranging the pile or column (14) to be floatable in water, moving the pile or column when floating to a location at which it is required to be erected, holding the floating pile or (14) against displacement from the location, and tilting the pile or column from a horizontal floating position to the required angular positioning with respect to the vertical, and setting the pile or column in the bed (SB) of the water at said location.

2 . A method of erecting a a pile or column or other column in the bed of a volume of water characterised by the steps of, rendering the pile or column (14) floatable in the water, displacing the pile or column whilst floating to a location at which it is desired to erect the pile or column, supporting/gripping the pile or column at a position (17) offset from the region of the centre of gravity of the pile or column, causing the pile or column to tilt under the action of gravity to its required orientation with respect to the seabed and setting the pile or column in the bed (SB) of the water at said location.

3. A method as claimed in claim 1 or 2, and characterised by the step of exerting lift upon the pile or column (14) at the offset position during said tilting to maintain the lower end of the pile or column clear of said bed.

4. A method as claimed in claim 1, 2 or 3, and characterised by the step of enabling water to enter into the interior of the pile or (14) during the tilting operation.

5. . A method as claimed in claim 5, characterised by the the step of admitting wwaatteerr iinnttoo tthhee lloowweerr eenndd ooff tthhee ppiillee oorr ccoolluummnn i (14) , and allowing air to escape from the upper end of the tilting pile or column..

6.. A method as claimed in any one of the preceding claims, characterised by the step of preventing over tilting of the pile or column (14) from a required setting.

7. A method as claimed in any one of the preceding claims, and characterised by the steps of physically gripping the pile or (14) at a predetermined location (17) offset from the centre of gravity thereof, and preventing over tilting of the pile or column beyond a required orientation..

8. A method as claimed in claim 6 or 7, and characterised by the step of preventing the over-tilting by buffering the movement of the pile or column (14).

9 A method as claimed in 7 or 8, and characterised by the step of additionally gripping the pile or column at a location above the first location of gripping therewith so as augment the support of the pile or (14) during the tilting hereof to a desired orientation.

10. A method claimed in any one of the preceding claims , and characterised by the step of lowering the pile or column (14) when the pile or column is at a required orientation so that the lower end thereof engages with the bed (SB) and fixedly locating said lower end relative to the bed. (SB) of the water at said location

11. A method as claimed in claim 9, and characterised by the step of causing the lower end of the pile or column (14) to enter into the bed (SB) of the water at said location to a required depth.

12. An installation for handling a pile or (14) for its erection at a predetermined location from the bed (SB) of a volume of water characterised by including means for locating the pile or column at said predetermined location, means for physically engaging with the pile or column (14) whilst it is floating in the water at a position (17) offset from the region of the centre of gravity of the pile or column (14) , and means (12) for enabling the pipe or column to tilt to a required orientation with respect to the said bed (SB),.

13 An installation as claimed in claim 12, and characterised in that the means for locating the pile or column (14) includes support elements (8,9) for mounting means (11, 12) for gripping/supporting the pile of column at a position (17) offset from the centre of gravity thereof, and means (12) for enabling the pile or column (14) to tilt to its required orientation whilst being gripped by the gripping means (12).

14 An installation as claimed in claim 13, and characterised in that the support elements (8,9) are elongate and are mounted from a support vessel or the (3) in such manner that the they may be displaced with respect to the support vessel such that the lower ends thereof may bear against the (SB) of the volume of water, and in that means (13,25) are provided to allow the gripping means (12) to displace relative to the support elements (8,9) to facilitate tilting of the pile or column (14) upwardly to a required orientation relative to said bed.

15 An installation as claimed 14, and characterised in that means (13,25) provided for enabling displacement of the gripping means relative to the support elements is such as to enable the lower end of the pile or column (14) o avoid fouling said bed during the tilting of the pile or column.

16. An installation as claimed in any one of claims 12 to 15, and characterised in that arrangements are provided whereby the pile or column (14) is enabled to tilt relative to the support elements (8,9) under the action of gravitational force.

17 An installation as claimed in claim 16, when in said arrangements involve the admission of water into the interior of the pile or column (14) in such manner as to increase below the location (17) of said gripping the weight of the pile or column gripping means whereby the force of gravity causes the pile or column to tilt relative to the support elements (8,9).

18 An installation as claimed in any one of claims 13 to 17, and characterised in that the support elements are elongate and are mounted from a support vessel or the like in such manner that the they may be displaced with respect to the support vessel such that the lower ends bear against the bed of the volume of water, and wherein means are provided to allow the gripping means to be displaced relative to the support elements the so as to enable the pile or column to be raised or lowered relative the the bed of the water.

19. An installation as claimed in any one of claims 13 to 18, and characterised in that the means for gripping/supporting the pile or column (14) includes a trough like formation (21) into which a selected length of the pile or column (14) is nestable whilst floating, and including closure means (22) serving to co-operate with that part of the pile or column (14) that is immediately opposite to the region thereof thereof engaged by the trough like formation (21) in such manner that the pile or column is firmly gripped.

20 An installation as claimed in any on of claims 14 to 19, and characterised by a second means (11) for gripping/supporting the pile or column (14) when in its required orientation at a location spaced above or below the position of the first mentioned (12) for supporting/gripping the pile or column (14) , the arrangement being such that when the pile or column has been set to its required orientation the second gripping/supporting means (11) is adapted to exert further grip on the pile or column to enable the pile or column to be displaced to such extent that its lower end can engage with the bed (SB) of the water, whilst being supported by the means/units (12.12) at two spaced apart locations lengthways of the pile or column (14)

21. An installation as claimed in claim 20, and characterised in that both said grpping/support means (11,12) are mounted from the support elements (8,9) the latter being located at opposite sides of a moon pool (4) in a vessel (3) and of such length the their lower ends are contactable with the bed (SB) of the volume of water, there being means (13) for enabling the simultaneous displacement of the gripping/supporting means lengthways of the members to lower the pile or column (14) so that the lower end thereof is contactable with the bed (SB) of the volume of water