EP2686488B1

EP2686488B1 - Method and apparatus for driving a pile into a substrate

Info

Publication number: EP2686488B1
Application number: EP12713256.1A
Authority: EP
Inventors: David Howel Gunter
Original assignee: IHC Sea Steel Ltd
Current assignee: IHC IQIP UK Ltd
Priority date: 2011-03-18
Filing date: 2012-02-23
Publication date: 2015-06-17
Anticipated expiration: 2032-02-23
Also published as: WO2012127201A1; DK2686488T3; GB201211946D0; EP2686488A1; GB201104612D0; GB2499686A

Description

TECHNICAL FIELD

The present invention relates to a method and apparatus for driving a pile into a substrate, particularly but not exclusively an uneven or undulating underwater substrate with localised variations in level.

BACKGROUND ART

It is known to provide pile guides for underwater piling, see for example, IHC Sea Steel Limited's range of pile guides as described in WO99/11872 (Fast Frame pile guide), WO01/92645 (Finned Frame/follower pile guide) and WO03/074795 (Orientation Control pile guide) or GB 2 467 842 A . Another IHC Sea Steel Limited pile guide, as described in WO2009/024739 , was specifically devised to allow for pile driving into an inclined substrate, such as the inclined side of a seabed canyon. The pile guide comprises a pile guide member which is pivotally mounted on a base frame to enable the pile guide member to pivot around an axis of rotation relative to the base frame. With such an arrangement, the orientation of the pile guide member may be adjusted to guide piles in a vertical orientation when the base frame rests on an inclined substrate with the axis of rotation horizontal (i.e. aligned transversely to the incline direction). However, such pile guides are not ideally suited for driving a pile into an uneven or undulating underwater substrate with localised variations in level. This is because such an underwater substrate will have a tendency to support the pile guide at different angles to the horizontal in different locations, which would result in piles being driven into the substrate in different, non-vertical orientations.
Yet another IHC Sea Steel Limited pile guide, as described in PCT/GB2011/050004 , was devised to allow for pile driving into an uneven or undulating underwater substrate with localised variations in level. The pile guide comprises a pile guide member mounted on a base frame via a plurality of support actuators of variable length, with length adjustment of each of the plurality of support actuators determining the orientation of the pile guide member relative to the base frame. However, with such an arrangement, the variable-length support actuators must be strengthened or protected to withstand lateral loads experienced by the pile guide during use. The present invention has been devised with this issue in mind.

DISCLOSURE OF INVENTION

In accordance with a first aspect of the present invention, there is provided a pile guide for supporting a pile as it is driven into a substrate, comprising: a base frame having a substrate-engaging surface; a plurality of pile guide members coupled to a support frame, each pile guide member being configured to guide a pile in a respective predetermined direction therethrough as it is driven into the substrate, the support frame being mounted on the base frame via a support arrangement configured to permit pivotal movement of the support frame relative to the base frame about a first axis of rotation.
With such an arrangement, the spacings between the pile guide members and the orientation(s) of their respective predetermined directions is determined by the support frame. At the same time, the orientation(s) of the respective predetermined directions of the pile guide members relative to the base frame may be altered to accommodate an uneven or inclined substrate which causes the base frame to rest in a non-horizontal plane. Thus, by pivoting the support frame relative to the base frame, it may be possible to align vertically the predetermined direction of at least one pile guide member when the base frame is resting on an inclined substrate. Moreover, since the support frame is mounted on the base frame via a support arrangement, there is no need for strengthened or protected support actuators.
The support arrangement may be further configured to provide pivotal movement of the support frame relative to the base frame about a second axis of rotation, thereby enabling the orientation of the support frame to be varied relative to the planar substrate-engaging surface of the base frame with two degrees of rotational freedom. Such a support arrangement enables variations in orientation of the support frame to be resolved into components in two different planes, each perpendicular to the planar substrate-engaging surface of the base frame. The two different planes may be orthogonal.
The support arrangement may comprise a mechanical coupling, such as a universal joint, a resiliently flexible member or a ball and socket joint. Alternatively or additionally, the support arrangement may comprise a resiliently flexible member, such as a coil spring or a rod of rubber or plastics material. The support arrangement may be configured to resist demounting of the support frame from the base frame, at least when exposed to lateral loading during deployment and/or pile driving
The plurality of pile guide members may be arranged around the support arrangement. For example, the pile guide members may be radially and circumferentially spaced from the support arrangement and a third axis lying perpendicular to the first and second axes of rotation. The pile guide members may be radially and/or circumferentially spaced equally from the support member. For example, if there are three pile guide members, the pile guide members may be angularly spaced by 120° to give equal circumferential spacing.
The pile guide may further comprise a releasable locking device for in use preventing pivotal movement of the support frame relative to the base frame. When the locking device is released, the support frame may be moved into a particular orientation relative to the base frame. Once the support frame is in the particular orientation relative to the base frame, the locking device may be applied to maintain it.
The pile guide member may further comprise at least one actuator for pivoting the support frame relative to the base frame. The or each actuator may be mounted on the base frame, spaced from the support arrangement, and may be coupled to the support frame or one of the plurality of pile guide members. The or each actuator may comprise a variable length strut. In one embodiment, a plurality of actuators for pivoting the support frame relative to the base frame are provided, with the support arrangement disposed between the plurality of actuators. In such an arrangement, the plurality of actuators may be configured to operate in sympathy with one another when pivoting the support frame relative to the base frame. The at least one actuator for pivoting the support frame relative to the base frame may also be configured subsequently to retain the support frame in a chosen position relative to the base frame. For example, if the or each actuator comprises a hydraulic ram, hydraulic control may be varied to drive pivotal movement and then resist subsequent movement.
The or each actuator may be configured to prevent rotation of the support frame relative to the base frame about a third axis which is perpendicular to the first and second axes of rotation.
The support frame may be an open space frame. Such a support frame may be rigid and relatively lightweight, and may have a limited hydrodynamic drag effect as the pile guide is lowered through water.
At least one of the pile guide members may comprise a simple hollow cylinder, or may be as disclosed in: WO01/92645 for use with piles with stabilising fins; WO03/074795 for use with piles with orientation control tabs; or WO2007/066078 for use with piles with profiles which interact with corresponding profiles in the pile guide member to resist bursting pressures in the latter. The entire contents of WO01/92645 , WO03/074795 and WO2007/066078 are incorporated herein by reference. The respective predetermined directions of the pile guide members may be mutually parallel.
In accordance with a second aspect of the present invention, there is provided a method of driving a pile into a non-level substrate, comprising: providing a pile guide according to the first aspect of the present invention; positioning the pile guide with the substrate-engaging surface of the base frame resting on the non-level substrate; tilting the support frame relative to the base frame until the predetermined direction of at least one pile guide member is aligned in a predetermined orientation (e.g. vertical).
The pile guide may have any of the features of embodiments of the first aspect of the invention.
The support frame may be tilted when the pile guide is in situ (i.e. positioned with the planar substrate-engaging surface of the base frame resting on the non-level substrate), even when the non-level substrate is underwater. Tilting of the support frame may be controlled automatically (e.g. with the aid of a level detector and control circuitry for controlling the at least one mechanism for pivoting the support frame relative to the base frame in response to output from the level detector). Alternatively, tilting of the support frame may be carried out remotely, with external means such as an ROV (remotely operated vehicle) providing feed back on orientation of the support frame relative to the base frame.
The method may further comprise driving a first pile through one of the plurality of pile guide members and driving a second pile through another of the plurality of pile guide members. The second pile may be driven into the substrate with the pile guide in the same location and the support frame in the same position relative to the base frame as when the first pile was driven into the substrate.

BRIEF DESCRIPTION OF DRAWINGS

An embodiment of the invention will now be described, by way of example, and with reference to the accompanying figures, in which:

Figure 1 is a perspective view of a pile guide embodying the present invention;
Figure 2 is a plan view of the pile guide of Figure 1; and
Figure 3 is a side elevation of the pile guide of Figure 1, with one part tilted relative to another part.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENT

Figure 1 illustrates a pile guide 10 embodying the present invention. The pile guide 10 comprises a base frame 12 having a planar substrate-engaging surface 14, and a plurality of (i.e. three) pile guide members 16 coupled to a support frame 18. Each pile guide member 16 is configured to guide a pile (not shown) in a predetermined direction (arrow A) relative thereto as it is driven into a substrate 20. The support frame 18 is mounted on the base frame 12 via a support arrangement 22 (in the form of a ball joint, one part of which is fixed to the base frame 12 and other half of which is fixed to the support frame 18) configured to provide pivotal movement of the support frame 18 relative to the base frame 12 about a first axis of rotation (R₁) and a second axis (R₂) lying substantially parallel to the planar substrate engaging surface 14. The support frame 18 may thus move relative to the base frame 12 with two degrees of rotational freedom. The pile guide members 16 are radially and circumferentially spaced from the support arrangement 22 and a third axis R₃ lying perpendicular to the first and second axes of rotation R₁ and R₂.
Each pile guide member 16 comprises a cylindrical sleeve 30 with a flared opening 32 to guide a pile into the cylindrical sleeve 30. The support frame 18 is an open space frame comprising a plurality of elongate rods 34. Some of the rods 34' extend between the pile guide members 16 and a common hub 36, whilst other rods 34" extend from one pile guide member 16 to another pile guide member 16.
Each pile guide member 16 is supported by a pair of variable length hydraulic rams 40 which are also mounted on the base frame 12. Each ram 40 is pivotally coupled at one end to the base frame 12 and is pivotally coupled at the other end to a respective pile guide member 16. The hydraulic rams 40 in each pair are mutually inclined to help prevent rotation of the support frame 18 relative to the base frame about a third axis which is perpendicular to the first and second axes of rotation. By operating the hydraulic rams 40 on opposite sides of the support arrangement 22 in sympathy, the support frame 18 can be tilted relative to the base frame 12.
The pile guide 10 may be deployed at sea and come to rest on a seabed 50 inclined at least 5° to the horizontal. The hydraulic rams 40' on the side of the pile guide 10 at the bottom of the incline must be extended at the same time as the hydraulic rams 40" on the side of the pile guide 10 at the top of the incline are retracted. In this way, the support frame 18 tilts relative to the base frame 12 about the support arrangement 22. With the support frame 18 horizontal, a first pile (not shown) may be driven vertically through one of the pile guide members 16 into the seabed 50 and a second pile may be driven through another of the pile guide members 16 into the seabed 50 without moving the pile guide 10. As known per se, rams 40' can be releasably locked so as to prevent unwanted extension/retraction, thereby preventing unwanted pivotal movement of the support frame relative to the base frame.
In another form (not shown), the pile guide member may be configured in accordance with the teachings of WO 01/92645 (the entire contents of which are incorporated herein by reference). In other words, the pile guide member may comprise a pair of upright guide channels for receiving and guiding a pair of stabilizing fins associated with a finned pile during pile driving. In yet another form (not shown), the pile guide member may be configured in accordance with the teachings of WO 03/074795 (the entire contents of which are incorporated herein by reference). In other words, the pile guide member may comprise a pair of helical guide plates of opposite senses of rotation which define a tapering channel for correcting any angular misorientation of a pile with a corresponding profile which engages part of the helical guide plates when passing through the pile guide member. In still yet another form (not shown), the pile guide member may be configured in accordance with the teachings of WO 2007/066078 (the entire contents of which are incorporated herein by reference). In other words, the pile guide member may have in its periphery a slot which is configured to allow a laterally protruding coupling attached to a pile to pass along the slot as the pile passes through the pile guide member. The pile guide member has a pair of profiles which are engaged by corresponding profiles on the pile as the pile passes through the pile guide, with reaction forces between opposing profiles resisting gaping of the slot.

Claims

A pile guide (10) for supporting a pile as it is driven into a substrate, comprising:
a base frame (12) having a substrate-engaging surface (14);

a plurality of pile guide members (16) coupled to a support frame (18), each pile guide member (16) being configured to guide a pile in a respective predetermined direction therethrough as it is driven into the substrate, the support frame (18) being mounted on the base frame (12) via a support arrangement (22) configured to permit pivotal movement of the support frame (18) relative to the base frame (12) about a first axis of rotation.
A pile guide according to claim 1, in which the support arrangement (22) is further configured to provide pivotal movement of the support frame (18) relative to the base frame (12) about a second axis of rotation.
A pile guide (10) according to claim 1 or claim 2, in which the support arrangement (22) comprises a mechanical coupling.
A pile guide (10) according to claim 3, in which the mechanical coupling is one of a universal joint, a resiliently flexible member and a ball and socket joint.
A pile guide (10) according to any preceding claim, in which the plurality of pile guide members (16) are arranged around the support arrangement.
A pile guide (10) according to claim 5, in which the plurality of pile guide members (16) are radially spaced equally from the support arrangement.
A pile guide (10) according to claim 5 or claim 6, in which the plurality of pile guide members (16) are circumferentially spaced equally around the support arrangement.
A pile guide (10) according to any one of the preceding claims, further comprising at least one actuator (40) for pivoting the support frame (18) relative to the base frame (12).
A pile guide (10) according to claim 8, in which the or each actuator (40) is mounted on the base frame (12) and is coupled to the support frame (18) or one of the plurality of pile guide members (16).
A pile guide (10) according to claim 8 or claim 9, in which the or each actuator (40) comprises a variable length strut.
A pile guide (10) according to any one of claims 8 to 10, in which the support arrangement (22) is disposed between a plurality of actuators (40) for pivoting the support frame (18), with the plurality of actuators (40) being configured to operate in sympathy with one another.
A pile guide (10) according to any one of the preceding claims, further comprising a releasable locking device for in use preventing unwanted pivotal movement of the support frame (18) relative to the base frame (12).
A method of guiding a pile being driven into a non-level substrate, comprising:
providing a pile guide (10) according to any one of claims 1 to 12;

positioning the pile guide (10) with the substrate-engaging surface (14) of the base frame (12) resting on the non-level substrate; and

tilting the support frame (18) relative to the base frame (12) until the predetermined direction of at least one pile guide member (16) is aligned in a predetermined orientation.
A method according to claim 13, further comprising driving a first pile through one of the plurality of pile guide members (16) and driving a second pile through another of the plurality of pile guide members (16) without moving the pile guide (10).