Abstract
The invention relates to a suction pile comprising a cylinder shaped body (1) with a closed end (3) and an open end (2), means (4) for attaching an arrangement to ejecting entrapped water, air and mud, but also provide a pressure difference within the suction pile during installation, and an attachment system (10) for attaching external equipment to the suction pile, the suction pile is formed with a skin portion (17) and at least one flange portion (6). At least one of the flange portions (6) comprises an element (11, 26) that form at least a part of the attachment system (10) for external equipment.
Claims
1. A suction pile comprising: a cylinder shaped body having a closed upper end and an open lower end, the body comprising at least one segment which includes a skin portion and at least one flange portion; and an attachment system for attaching external equipment to the suction pile; wherein at least one of the flange portions comprises an increased thickness in at least one direction compared to the skin portion; wherein at least one of the flange portions comprises an element that forms at least a part of the attachment system; wherein the flange portion comprising the element extends from the closed end and at least partly along the cylindrical shaped body; and wherein the body is formed of at least two segments.
2. A suction pile according to claim 1, wherein the flange portions extend into the interior of the cylinder shaped body and the closed end.
3. A suction pile according to claim 1, wherein each segment comprises a flange portion at each of its ends which faces a neighboring segment.
4. A suction pile according to claim 3, wherein the element forming at least a part of the attachment system is positioned in a flange portion facing a flange portion of a neighboring segment.
5. A suction pile according to claim 3, wherein the attachment system comprises: at least one recess formed in at least one flange portion of at least one of the segments; and at least one attachment piece which comprises a first section having complimentary form to the recess and a base section which is connected to the first section; where the attachment system is configured such that when one segment is connected to a neighboring segment, the attachment piece is positioned with the first section within the recess and with the base section extending a distance out of the suction pile.
6. A suction pile according to claim 5, wherein the attachment system comprises at least three recesses, within each of which one attachment piece is positioned, and wherein each recess is positioned between different neighboring segments.
7. A suction pile according to claim 5, wherein the flange portions facing each other are formed with mirrored recesses.
8. A suction pile according to claim 5, wherein the first section of the attachment piece has a width which is larger than a width of the base section.
9. A suction pile according to claim 5, wherein the attachment system comprises a base plate which is connected to at least one base section and is positioned on an outside of the suction pile.
10. A suction pile according to claim 1, wherein at least one segment is at least partially formed from a composite material.
11. A suction pile according to claim 1, wherein the cylinder shaped body comprises a cylindrical wall portion and the closed upper end comprises an end portion, and wherein a majority of the segments are substantially equal and each segment forms a part of the cylindrical wall portion and a part of the closed end portion.
12. A suction pile according to claim 1, where the attachment system is positioned in the closed end of the suction pile.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is a perspective view of a first embodiment of a suction pile according to the invention;
(2) FIG. 2 is a front view of the suction pile shown in FIG. 1 with one segment removed;
(3) FIG. 3 is an enlarged view of “Detail A” of FIG. 2;
(4) FIG. 4 is an enlarged perspective view of “Detail A” of FIG. 2;
(5) FIG. 5a to FIG. 5f are front and perspective views of different shaped attachment pieces of the invention;
(6) FIG. 6a to FIG. 6d are top and perspective views of different shaped base plates of the invention;
(7) FIG. 7a to FIG. 7c are views of an alternative embodiment of an attachment system of the invention, with FIGS. 7a and 7b being two different perspective views of the system and FIG. 7c being a detail of FIG. 7b;
(8) FIG. 8 is a perspective view of a second embodiment of a suction pile according to the invention; and
(9) FIG. 9 is a perspective view of a third embodiment of a suction pile according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
(10) FIG. 1 is a perspective view of one embodiment of the invention. The suction pile shown in FIG. 1 has a cylindrical shaped body 1 having an open end 2 and a closed end 3. The suction pile includes means 4 for attaching a ventilation system (not shown) for ejecting entrapped water, air and mud from the body 1. The suction pile also has means (not shown), or a part of the means 4, for attaching a pumping system for creating a suction pressure within the cylindrical shaped body 1 as the suction pile is positioned into the seabed. The suction pile is further made of a number of segments 5. In the embodiment shown in FIG. 1 the suction pile is made of six equal segments 5. In the embodiment shown in FIG. 9 the suction pile is made of one segment 5. It is of course also possible to envisage a suction pile according to the invention which is made of two, three, four, five, six, seven, eight, nine, ten, eleven, twelve or more segments. The number of segments will vary dependent on the size of the suction pile. It is also possible to envisage a suction pile with the majority of segments being equal in shape but with some segments differing in shape from the majority of segments.
(11) In the embodiment shown in FIG. 1, each of the segments 5 has an outer skin portion 17 that comprises a portion which forms part of the cylindrical wall 7 and a portion which forms part of the closed end 3, the latter portion including a transition portion 8 and a flat portion 9. The transition portion 8 has a curvature between two linear portions with about 90 degrees difference in orientation. The radius of the curvature of the transition portion 8 will depend on the size and use of the suction pile. It is also possible to envisage a suction pile with side walls 7 and a closed end 3 where the closed end is formed in a different manner than described above. The closed end 3 may be formed with an apex in the center or with another form other than flat in one central portion. These forms may also be considered to have a central portion and a transition portion. A transition portion may comprise both curved parts and linear parts.
(12) The suction pile also comprises an external attachment system 10 in the form of six attachment points in the embodiment shown in FIG. 1. The external attachment system is provided to connect with a subsea structure or other external structure (not shown) which needs the support of the suction pile. The attachment points of the attachment system 10 are positioned at the connections between the different segments 5 forming the suction pile.
(13) As best shown in FIG. 2, each of the segments 5 forming the suction pile is formed with flange portions 6 at the sides of the segments 5 facing a neighboring segment. It is possible to see four flange portions 6 in FIG. 2, two of which are facing the removed segment, namely, a flange portion of segment 5 and a flange portion of segment 5b, and two of which are positioned next to each other, namely, the flange portions of segments 5a and 5b when these two segments are connected together. The flange portions 6 extend inward into the interior of the suction pile. The flange portions are also extend along the closed end 3 and along the cylindrical wall 7 of the suction pile.
(14) The flange portions 6 in the shown embodiment are formed with a rounded lower portion 61 close to the open end 2 of the suction pile. This form will ease the movement of the suction pile into the soil of the seabed. The flange portion then continues with a straight portion 62 for a distance along the wall 7 of the suction pile. The flange portion then continues in a sort of triangular shaped portion 63 which extends from a point at the cylindrical wall 7 through the transitions portion 8 and up to the flat portion 9 of the closed end 3. The width of a flange portion is defined as the distance between the distal end of the flange portion and the skin 17 of the segment 5. The width of the flange portion varies for the triangular shaped portion 63 in the shown embodiment. The end of the triangular shaped portion 63 facing inward forms a mainly linear edge. In another embodiment this end may form a curved edge. The triangular shaped portion 63 is a portion of increased width of the flange portion compared with the other portions of the flange portion. The flange portion shown in the figure ends with an end portion 64 in the closed end 3 of the suction pile. The flange portion 6 also includes, in a surface facing a neighboring segment when connected, grooves or corrugations 65 extending along the flange portion. The grooves 65 may extend mainly parallel with the skin portion 17 of the segment. As seen in FIG. 2, the segments 5 are not provide with flange portions at sides not facing neighboring segments, which may be seen at the open end 2. The segments 5 are also not formed with flange portions at the open end 2.
(15) These flange portions 6 of the segments 5 face inward into the suction pile. However, it is possible to envisage them facing outwards or both inwards and outwards. It is also possible to envisage the segment 5 not extending into the center of the flat portion of the closed end 3, but instead having a circular segment forming at least a part of the flat portion of the closed end. This possible circular segment may form only a smaller part of the flat portion of the closed end.
(16) The external attachment system may be formed in different manners; one embodiment is shown in FIGS. 3 and 4. FIG. 3 shows Detail A of FIG. 2, and FIG. 4 shows the embodiment of FIG. 3 with part of the attachment system removed for clarity. The external attachment system comprises a recess 11 formed in the flange portion 6 or part of a segment 5, as best shown in FIG. 4. There may be a recess in the flange portion in only one of the segments or in both flange portions so that they together form a common recess 11 when connected to each other. The recess 11 is formed in the flange portion at a position which, when the segments are connected, will be at the relative outside of the grooves 65.
(17) Within this recess 11 is positioned an attachment piece 12. If the segments 5 are made of a composite material, the attachment piece 12 may be of another material (metal, for instance steel). The attachment piece 12 is formed with a first section 13 and a base section 14. The first section 13 has a first width 21 which is larger than a second width 22 of the base section 14. The recess in the flange portion has a corresponding shape. When connected, the base section extends to the outside of the suction pile and forms a basis for attaching external equipment. The first section 13 is positioned in the recess 11 between the flange portions of two neighboring segments 5 and is kept in this position by the connection of the segments 5 to each other. The recess 11 and the attachment piece 12 have complimentary forms. Thus, the recess 11 must be large enough to accommodate the attachment piece 12 and also present a smaller width close to the skin portion 17 to keep the attachment piece locked in the recess when segments 5 are joined together. The recess 11 may be larger than the attachment piece 12. However, as with the attachment piece 12, the recess 11 has an inner part with a larger width and an outer part with a smaller width, similar to the first and second widths 21 and 22 of the attachment piece 12. If the recess 11 is larger than the attachment piece 12, the recess 11 would normally be filled with an adhesive material, for instance epoxy or a similar material, when the attachment piece is positioned within the recess. This will fill any voids and prevent movement between the attachment piece and the segments 5. In the embodiment shown in FIG. 3, the attachment piece forms a upside down T-shape with the top of the T as the first section 13 and the bottom part or root of the T as the base section 14. The top part of the T facing the outer surface 16 of the suction pile is closer to the outer surface at the distal ends than at the middle. The base section 14 extends from the first section 13 out beyond the outer surface 16 of the suction pile. A base plate 15 is connected to the base section 14 at the outside of the suction pile. If the flange portions 6 of the segments 5 extend outwards instead of inwards as in the shown example, the base section 14 of the attachment piece would extend outside an outer end of the flange portions.
(18) As one may see from FIG. 4, the external attachment system is positioned in the flange portions 6 of the segments 5 and not in the skin portions 17 between the flange portions 6. The external attachment system is positioned in the flange portion 6 at an outer circumference of the flat portion 9 of the closed end 3, or close to where the transition portions 8 and the flat portions 9 of the closed end are connected, as indicate with the line L in FIG. 4. It is possible to envisage another point for positioning the recess and attachment piece which is in the transition portion 8 of the closed end. The closed end may as previous mentioned also be formed without the flat portions located centrally in the closed end.
(19) The attachment piece 12 and the recess 11 may have many different shapes, some of which are indicated in FIGS. 5a to 5f. The commonality between these attachment pieces is the existence of a first section 13 with a first width 21 and a base section 14 with a second width 22. The first width 21 is larger than the second width 22 and the recess has complimentary differences in the width to thereby keep the attachment piece 12 within the recess 11 when segments 5 are connected. This is the case with the upside down T-shape in FIG. 5a, the upside down lollipop shape with a through going opening in FIG. 5b, and the upside down lollipop shape without an opening in FIG. 5c. It is also the case with the upside down “tree” in FIG. 5d, which is also a sort of T with two top bars of the T located one above the other. In FIG. 5e the attachment piece 12 is given a U-shape, wherein the bottom of the U forms the first section 3 and the two legs of the U together form the base section 14. In FIG. 5f a bar forms the first section 13 and two legs extending up from positions along this bar form the base section 14.
(20) As shown in FIG. 5a the base section 14 may comprise a locking part 14a to prevent the base plate 15 from being involuntary released from the base section 14 opposite the first section 13, or possibly at a point along the base section 14 (not shown). In FIGS. 6a to 6d are shown some possible embodiments of base plates 15. In FIG. 6a is shown one rectangular base plate with a through going opening 23 for threading the base plate onto the base section 14 which extends out of the suction pile surface. The opening 23 also has a guide part 24 and a smaller centering part 25. The base plate may as shown in FIG. 6b also be made with an opening 23 in the shape of the cross section of the base section 14. The base plate may also be formed so that it can be connected to two base sections of different attachment pieces or two base sections of one attachment piece, thereby providing two openings 23 in the base plate as shown in FIG. 6c. In such an instance it is favorable to provide the openings with a guide part 24 and a centering part 25. As seen in FIG. 6d, the base plate may also be formed as one unit to be linked to all the different attachment pieces 12 in the attachment system. One possible embodiment is then to form the base plate as a ring shaped element with openings 23 for the different base sections 14. Another possibility is to provide a larger circular or other shaped plate (not shown) which is connected to all the different attachment pieces in the attachment system. The objective here is to provide a basis to position or attach external equipment on or to the suction pile while at the same time providing the necessary access for the pumping equipment which creates suction pressure within the suction pile and also enabling the loads from the external equipment to be transferred down into the suction pile.
(21) In FIG. 7 is shown a different embodiment of the attachment system according to the invention. In this embodiment the segments are formed with integral attachments pieces 26 in the flange portions 6 of the segments 5. Instead of a recess in the flange portion 6, an extension 26 from the surface of the segment forms part of the attachment system for external structures. These extensions 26 extend in the opposite direction of the main flange of the flange portion 6.
(22) FIG. 8 shows a second embodiment of a suction pile of the present invention. The suction pile is made up of three mainly equal segments 5, all forming a part of the closed end 3 and the cylinder wall 7 of the suction pile. In addition, an additional segment 5′ is provided in the center of the closed end of the suction pile. The segments 5 are formed with skin portions 17 and flange portions 6. The flange portions 6 are provided in the connection between the segments and extend inwards into the suction pile. The additional segment 5′ is also formed with a skin portion and a circular flange portion 6. The three other segments 5 are also formed with a curved flange portion 6 cooperating with the flange portions 6 of the addition segment 5′. The flange portions 6 between the three segments 5 are also formed with an element that forms at least a part of the attachment system for external equipment, in this case recesses in the connection between the flange portions 6 of neighboring segments 5 (not visible in the drawing). The configuration with a number of mainly equal shaped segments and one other formed segment in the closed end may be used with other numbers of mainly equally shaped segments.
(23) FIG. 9 shows another embodiment of a suction pile of the invention, in which the suction pile is formed with one segment 5. The segment is formed with skin portions 17 and flange portions 6. One flange portion 6 is formed as an outward extending flange portion 6 in the closed end of the suction pile. This flange portion 6 forms an element that defines at least a part of the attachment system for external equipment. The suction pile may also be formed with other flange portions extending inward in the suction pile, which are not shown in the drawing.
(24) The invention has now been explained and described with reference to the attached drawings. A skilled person would understand that alterations and amendments to the described embodiment may be made that are within the scope of the invention as defined in the attached claims. The flange portions may extend inwards or outwards or even in both directions. The suction pile may be formed of mainly equal segments or a majority of equal segments and some segments having another shape. Most or all of the segments may be made of a composite material.
