Pile driving guide

Abstract

A pile guide is provided comprising a base frame and a superstructure comprising a pile guide member for guiding the pile as it is driven into a substrate when the base frame is resting thereon. At least part of the superstructure defines an arm that is rotational with respect to the base frame about a first and second points of rotation, to rotate the pile guide member with respect to the base frame. At least one of the first and second points of rotation is translatable with respect to the base frame in a first direction, thereby rotating the arm about the first and second points of rotation with respect to the base frame. At least one of the first and second points of rotation is translatable in a second direction substantially perpendicular to the first and second points of rotation with respect to the base frame direction. A method is also provided.

Claims

1. A pile guide comprising: a base frame, and a superstructure, the superstructure comprising a pile guide member configured to guide a pile in a predetermined direction as it is driven into a substrate when the base frame is resting thereon, wherein at least part of the superstructure defines an imaginary arm of fixed length that is rotational with respect to the base frame about a first axis of rotation extending through a first point of rotation separated from the pile guide member and about a second axis of rotation extending through a second point of rotation separated from the pile guide member, to rotate the pile guide member with respect to the base frame, a separation of the first point of rotation and the second point of rotation defining the fixed length of the imaginary arm, wherein at least one of the first and second points of rotation is translatable with respect to the base frame in a first direction substantially perpendicular to the base frame, thereby rotating the imaginary arm about the first and second points of rotation with respect to the base frame, and wherein at least one of the first and second points of rotation is translatable with respect to the base frame in a second direction substantially perpendicular to the first direction maintaining the separation of the first and second points of rotation along the direction of the length the imaginary arm constant, and wherein the first direction and the second direction are substantially perpendicular to the first axis of rotation and the second axis of rotation.

2. The pile guide of claim 1, wherein at least one of the first and second points of rotation is floatable in the second direction substantially perpendicular to the first direction.

3. The pile guide of claim 1, wherein at least part of the pile guide member defines the imaginary arm.

4. The pile guide of claim 1, wherein at least one of the first and second points of rotation is supported by an adjustable support member mounted on the base frame, such that by adjustment of the support member, the respective point of rotation is translatable in the first direction with respect to the base frame.

5. The pile guide of claim 1, wherein the superstructure comprises plural pile guide members.

6. The pile guide of claim 1, wherein at least one of the first and second points of rotation is defined by a joint, at least part of the joint being movable with respect to the base frame, wherein the pile guide member has a central axis from a first end proximate the substrate and a second end remote from the substrate, the central axis extending in the predetermined direction, the superstructure being movably supported on the frame to allow movement of the pile guide member in a direction having a component along the central axis.

7. The pile guide of claim 6, wherein the joint has a floatable bush or bearing.

8. The pile guide of claim 6, wherein the joint includes an elongate slot, and wherein the at least one of the first and second points of rotation is arranged to pass through a floating member that is translatable within the elongate slot.

9. The pile guide of claim 1, wherein the pile guide member comprises a plurality of guide parts each moveable between an operative position and an inoperative position, each guide part being pivotally mounted on the base frame about a respective pivoting axis, wherein at least one of the respective pivoting axes is rotatable about at least one of the first and second points of rotation.

10. The pile guide of claim 9, wherein each guide part is pivotally mounted on the base frame about a respective pivoting axis for opening of the pile guide member to its inoperative position under gravity.

11. The pile guide of claim 9, wherein one of the respective pivoting axes is rotatable about the first point of rotation and another one of the respective pivoting axes is rotatable about the second point of rotation.

12. The pile guide of claim 9, wherein the respective pivoting axes are substantially parallel on opposite sides of the pile guide member and the first and second points of rotation are on opposite sides of the pile guide member.

13. The pile guide of claim 9, wherein at least one of the respective pivoting axes extends in an axial direction and is slidable in the axial direction with respect to the respective first or second point of rotation.

14. The pile guide of claim 9, wherein the pile guide member comprises a first guide part and a second guide part each moveable between an operative position and an inoperative position, the first guide part being pivotally mounted on the base frame about a first pivoting axis positioned on a first side of the pile guide member, and the second guide part being pivotally mounted on the base frame about a second pivoting axis positioned on an opposite side of the pile guide member with respect to the first pivoting axis, the first and second pivoting axes being substantially parallel to each other and extending in an axial direction, wherein the first pivoting axis is rotatable about the first point of rotation and a third point of rotation, and the second pivoting axis is rotatable about the second point of rotation and a fourth point of rotation, wherein the first pivoting axis is slidable in the axial direction with respect to the first or third point of rotation, and the second pivoting axis is slidable in the axial direction with respect to the second or fourth point of rotation.

15. The pile guide of claim 14, wherein at least one of the third and fourth points of rotation is translatable with respect to the base frame in the first direction.

16. A method of operating a pile guide comprising: arranging a pile guide on a substrate, the pile guide comprising a base frame and a superstructure, the superstructure comprising a pile guide member for guiding a pile in a predetermined direction along a central axis as it is driven into a substrate when the base frame is resting thereon, the superstructure being movably supported on the frame to allow movement of the pile guide member in a direction having a component along the central axis, wherein at least part of the superstructure defines an imaginary arm of fixed length between a first point of rotation and a second point of rotation that is rotatable with respect to the base frame about the first point of rotation and the second point of rotation, to rotate the pile guide member with respect to the base frame, translating at least one of the first and second points of rotation with respect to the base frame in a first direction, thereby rotating the imaginary arm about the first and second points of rotation, wherein the first direction is substantially perpendicular to the base frame, and translating at least one of the first and second points of rotation with respect to the base frame in a second direction substantially perpendicular to the first direction due to rotation of the imaginary arm of fixed length which maintains a constant separation between the first point of rotation and the second point of rotation during rotation of the imaginary arm.

17. A pile guide comprising: a base frame, and a superstructure, the superstructure comprising a pile guide member configured to guide a pile in a predetermined direction as it is driven into a substrate when the base frame is resting thereon, the pile guide member having a central axis from a first end proximate the substrate and a second end remote from the substrate, the central axis extending in the predetermined direction; wherein at least part of the superstructure defines an imaginary arm of fixed length between a first point of rotation and a second point of rotation that is rotational with respect to the base frame about the first point of rotation and the second point of rotation, each point of rotation being where a portion of the superstructure is connected to and rotates with respect to the base frame, wherein the superstructure is movably supported on the frame to allow movement of the pile guide member in an axial direction along the central axis, wherein at least one of the first and second points of rotation is translatable with respect to the base frame in a first direction substantially perpendicular to the base frame, thereby rotating the imaginary arm of fixed length about the first and second points of rotation with respect to the base frame, and wherein at least one of the first and second points of rotation is translated in a second direction with respect to the base frame substantially perpendicular to the first direction when the imaginary arm of fixed length rotates.

18. The pile guide of claim 17 wherein each of the first point of rotation and the second point of rotation are separate from the pile guide member.

19. The pile guide of claim 18 wherein the imaginary arm is configured such that when at least one of the first and second points of rotation is translatable in the second direction a length of the imaginary arm maintained constant.

20. The pile guide of claim 17 wherein the imaginary arm is configured such that when at least one of the first and second points of rotation is translatable in the second direction a length of the imaginary arm maintained constant.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above-described aspects will hereafter be more explained with further details and benefits with reference to the drawings showing an embodiment of the invention by way of example.

(2) FIGS. 1 and 1A are side and perspective views of a known pile guide in generally perpendicular orientation of the pile guide relative to the base frame;

(3) FIG. 2 shows the pile guide of FIG. 1 being inclined with respect to the base frame;

(4) FIG. 3 schematically shows a detail of the pile guide of FIGS. 1-2;

(5) FIGS. 4-6 are views like FIGS. 1-3 of an improved pile guide;

(6) FIGS. 7-7A are side and perspective views like FIGS. 3, 6 and 1A, 4A, respectively, of an improved pile guide.

DETAILED DESCRIPTION OF EMBODIMENTS

(7) It is noted that the drawings are schematic, not necessarily to scale and that details that are not required for understanding the present invention may have been omitted. The terms upward, downward, below, above, and the like relate to the embodiments as oriented in the drawings, unless otherwise specified. Further, elements that are at least substantially identical or that perform an at least substantially identical function are denoted by the same numeral.

(8) FIGS. 1-3 show a pile guide 1, for supporting a pile as it is driven into a substrate, with FIG. 3 only showing a detail. The pile guide 1 comprises a base frame 3 and a superstructure 4, here mainly being a pile guide member 5 for guiding the pile (not shown) as it is driven into a substrate (not shown) when the base frame is resting thereon. Typically, the pile guide 1 is used for driving piles under water in a seabed, river bed or the like, and the base frame 3 may also be referred to as a mud mat.

(9) The pile guide member 5 extends along a central axis CA and comprises two guide parts 7, in turn comprising a generally concave main body portion 7A and a support frame 7B. Each guide part 7 is pivotally mounted on the base frame 3 for rotation about a respective pivot axis 8 and movable by rotation about the axes 8 between a closed operative position (shown) and an open inoperative position (not shown here, but detailed in the aforementioned WO publications). In the closed situation, the guide parts 7 are connected by a latch 13, usually a pair of latches 13 arranged at or near the top of the guide member 5. The pivot axes 8 extend generally parallel to each other and perpendicular to the central axis CA, and perpendicular to the plane of FIGS. 1, 2 and 3, FIG. 1A being a perspective view. Each guide part 7 may be coupled with an associated counterweight (not shown) for opening of the guide member 5 under gravity, and/or they may be coupled with another device for opening under action by the device.

(10) The superstructure 4 is generally rigid and is connected to the pivot axes 8. The superstructure 4 defines an (imaginary) arm extending through both joints 9. The separation between the joints 9 has a base length b. The length of the arm also equals b.

(11) The pivots axes 8 are rotatably mounted in joints 9 which are supported in adjustable support members 11 mounted on the base frame 3 and extending substantially perpendicular to it. E.g., the support member 11 may comprise a rail along which part of the joint 9 is movable e.g. by being supported by a hydraulic piston.

(12) In the configuration of FIGS. 1-1A, the joints 9 are at equal heights above the base frame 3 and the base frame 3 and (the axes 8 of) the superstructure 4 are generally parallel.

(13) As an example of adjustment of a support member 11, e.g. on the right-hand side of the pile guide 1, the respective joint 9, and with it the pivot axis 8, is translatable in a first direction (here: vertical) with respect to the base frame 3 (compare FIGS. 1-3). E.g., in the configuration of FIGS. 2 and 3, the positions of the joints 9 relative to the base frame 3 are adjusted by raising the right joint 9 with respect to the configuration of FIG. 1 over a distance c by adjustment of the respective support member 11. As a consequence, the superstructure 4 with the guide member 5 is inclined with respect to the base frame 3 (FIG. 2) over an angle , wherein the connections of the superstructure 4 with the base frame 3 provide points of rotation R with respect to the base frame, here coinciding with the pivot axes 8 which rotate in the joints 9.

(14) However, (FIGS. 2-3) the lateral separation a of the support members 11 is constant, whereas the separation b of the joints 9 along the direction of the arm increases according to: separation=a tan , the tangent having an approximately linear relation to the angle for small values of that angle. This results in stress in the pile guide 1 which may cause deformation of one or more portions of the pile guide 1. As a result of such stress, the guide parts 7 may separate at least partially and produce a gap G when held together by the latch 13, as indicated in FIG. 2. Thus, the latch 13 is subject to undesired loads and the guiding of the pile and/or reliability of the pile guide 1 may be compromised. Since the stresses scale with the arm length a, the problem gets worse with increasing size of the superstructure 4.

(15) The customary strategy of fortifying the pile guide 1 to combat such stresses causes significant increases in the mass of the apparatus. Therefore, sizes of existing pile guides tend to be limited in practice. It also amounts to combating symptoms without addressing their cause.

(16) FIGS. 4-6 show, in similar views as FIGS. 1-3, an improved pile guide 1. This embodiment is largely similar to the pile guide 1 of FIGS. 1-3. However, in this embodiment joints 9A are provided, wherein the pivot axes 8 are translatable parallel to the base frame 3, perpendicular to the vertical direction. Here, the pivot axes 8 are generally freely sideways floatable in the joints 9A in the support members 11. Thus, when inclining the superstructure as before (compare FIGS. 5-6 with FIGS. 2-3) the lateral separation a of the support members 11 is constant, but now the separation b of the joints 9 along the direction of the arm is maintained constant, and the lateral separation of the pivot axes 8 (parallel to the base substrate 3) is reduced with a cos (separation=b cos , in this case). Thus, stresses on the pile guide 1 are reduced, and deformation of the guide member 5, which may lead to the aforementioned gap G between the guide members 7, is prevented. Also, the latch 13 may be constructed lighter-weight and/or it may be arranged at a different position so that forces in the guide member 5 are distributed more evenly. The guide parts 7 may be supported off each other with optional contact pads 14 further evening forces within the guide member 5. Further, larger pile guides may be constructed robustly at more easily manageable weight.

(17) In the embodiment of FIG. 4A, two pivot axes 8 extend parallel in a Y-direction and are adjacent to each other in an X-direction, being supported in opposite adjustable supports 11 (as indicated in the reference-axes frame for directions X, Y and Z). By individual and/or pairwise adjustment of supports 11 in Z-direction, the positions of the joints 9A may be adjusted and thus the orientation of pivot axes 8 and that of (the central axis CA of) the pile guide member 5 as a whole may be adjusted relative to the base frame 3 in arbitrary directions, e.g. inclining the pile guide member 5 in X- and/or Y-direction(s). To prevent stresses in the pile guide 1, one or more joints 9A may (also) be constructed to allow motion of the respective pivot axis 8 in longitudinal direction of that axis, e.g. as in accordance with the concepts of WO 2011/083324. Both the presently provided concepts and those of WO 2011/083324 may be combined in a single joint assembly, e.g. by arranging a pivot longitudinally slidably in a bush- or ball shaped joint member, that, in turn, is laterally slidable in a counter part which is translatable perpendicular to the direction of lateral sliding, e.g. substantially perpendicular to the base frame 3 or the superstructure 4.

(18) The principles of operation and their benefits apply equally well when the left-hand joint 9 is translated vertically by its support member 11 with or without vertical translation of the right-hand joint 9 by its support member 11, and/or if both joints are configured for lateral motion of the respective point of rotation R (here: the respective pivot axis 8).

(19) FIG. 7 is a side view of another embodiment, comprising a superstructure 4A having plural pile guide members 5, one or more of which may have guide parts 7 that are moveable between an operative position and an inoperative position (not shown). FIG. 7A is a (very) schematic perspective view of this pile guide 1A. In this embodiment, four corners of the superstructure 4A are supported so as to be translatable perpendicular to the base frame 3, so that the superstructure 4A may be inclined to the base frame 3, like the superstructure 4 of FIGS. 4-6. The connections between the base frame 3 and the superstructure 4A provide points of rotation R of the parts (3, 4A) with respect to each other, between which points of rotation R the (imaginary) arm is spanned, having length b. Due to the lateral freedom of motion of the point of rotation R (right side in FIG. 7), both the arm length b and the separation a between supports 11 can be maintained substantially constant under adjustment of the angle of inclination a to reduce or prevent stresses and/or deformation. Here, again, the points of rotation R are moveable by a floatable joint 9A, however, the points of rotation R do not coincide with pivot axes 8. Otherwise, the embodiment and its operation are largely similar to that of FIGS. 4-6.

(20) The inclination of (a superstructure 4, 4A of) a pile guide 1, 1A as provided herewith may be adjustable in two substantially perpendicular directions, so that the central axis CA of the guide member 5 may be arranged in arbitrary desired orientations over an available solid angle e.g. defined by adjustable support members. In such case, more points of rotation R are present which may be translatable in a direction generally parallel to the base frame 3 or the superstructure 4, 4A, perpendicular to the respective direction of translation for adjustment of the inclination.

(21) It is noted that a translatable joint is suitable, e.g. having a floatable bush and/or bearing, but a pivot slidably resting on a support and/or suspended from a laterally deformable object such as a chain or cable could be envisioned.

(22) Summarising, operation and use of the pile guide (e.g. 1) may comprise the following steps:

(23) a) arranging an embodiment of a pile guide 1 as described herein on a substrate, e.g. underwater, on the seabed;

(24) b) translating at least one of the first and second points of rotation with respect to the base frame 3 in a first direction, thereby rotating the arm about the first and second points of rotation, and

(25) c) translating at least one of the first and second points of rotation in a second direction substantially perpendicular to the first direction.

(26) In an embodiment, the steps b and c are performed substantially concurrently, which prevents arm length variations and/or stresses during either translation.

(27) In view of the harsh conditions of pile driving, in particular offshore subsea pile driving, pile guides have traditionally been developed with continuously increased robustness and simplicity, reducing the number of parts and/or providing parts as unitary objects and/or substantially permanently fixed together objects (e.g. welded or riveted) wherever possible. It has now been found that such robustness may, in fact, not be needed and that, by increasing complexity of the pile guide against the traditional trend, by making parts movable with respect to each other, the pile guide's overall robustness may be increased and its weight may be significantly reduced.

(28) The invention is not restricted to the above described embodiments which can be varied in a number of ways within the scope of the claims. For instance it is possible that more or less and/or different translators are provided to translate the points of rotation than the shown and discussed support members 11. Lateral translation may be passively, e.g. floating, and/or under operation of one or more actuators, e.g. comprising one or more hydraulic cylinders. Further, more guide parts may be used in a superstructure, the guide member and/or guide part frame may differ, the base frame may be smaller, larger and/or differently formed, etc. Also, plural pile guides may be combined, possibly detachably, to a multi-pile guide template. Connections for hoisting arrangements and/or for connecting with an Remotely Operated Vehicle (ROV) e.g. for power requirements may be provided.

(29) Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise.