SCOUR PROTECTION SYSTEMS, METHODS, AND APPARATUS

Abstract

Systems, methods, and apparatus are disclosed involving scour protection of undersea monument foundations, such as monopile foundations. A preferred embodiment comprises an Advanced Ecological Scour Protection System (AESPS) that enhances offshore scour protection through an innovative combination of eco-friendly engineering units and natural materials. In a preferred embodiment, an AESPS includes two main features comprising a single-layer rock blanket deployed first at an intended site of the foundation, followed by installation of fronded eco-concrete mattress units to form a peripheral ring border around the rock blanket. The foundation then may be installed directly into and through the rock blanket, with a monument installed on the foundation, and an export cable extending from the monument, over the mattress units, and through the fronds. Such an AESPS may eliminate critical risks of secondary scour damage, cable lateral movement, and marine life deterioration.

Claims

1. An apparatus assembly adapted for use in protecting an undersea monument foundation against undersea scour, the apparatus comprising: a single-layer gravity-based protection of a central area centered around a center of the undersea monument foundation, and a fronded concrete mattress border covering and surrounding a periphery of the single-layer gravity-based protection.

2. The apparatus assembly of claim 1, the apparatus assembly further comprising: an export cable extending from the undersea monument foundation, extending over the single-layer gravity-based protection, and extending over the fronded concrete mattress border, wherein the export cable rests among and between fronds extending from fronded concrete mattress border.

3. The apparatus assembly of claim 1, wherein the single-layer gravity-based protection comprises: a rock blanket, wherein the rock blanket is adapted to be applied on an undersea ground surface, over and around the center of the undersea monument foundation.

4. The apparatus assembly of claim 1, wherein the fronded concrete mattress border comprises: a plurality of fronded concrete mattresses, wherein the plurality of fronded concrete mattresses is adapted to be positioned around the periphery of the single-layer gravity-based protection to form a peripheral ring on, over, and around an edge of the single-layer gravity-based protection at a border of the single-layer gravity-based protection and a ground surface of the undersea ground.

5. A system adapted for use in protecting an undersea monument foundation against undersea scour, the system comprising: an application of a single-layer gravity-based protection to a central area adapted to be centered around a center of the undersea monument foundation, and an installation of a fronded concrete mattress border covering and surrounding a periphery of the single-layer gravity-based protection; wherein the application of the single-layer gravity-based protection is adapted to be applied to an undersea ground surface at an intended site of the undersea monument foundation, with the central area central to the intended site; wherein the installation of the fronded concrete mattress border is adapted to be installed below and support any export cable exiting a monument positioned on a foundation installed at the intended site, and wherein a plurality of fronds of the fronded concrete mattress is adapted to engage and shelter the export cable supported on the installation.

6. The system of claim 5, the system further comprising: the export cable extending from the undersea monument foundation, extending over the single-layer gravity-based protection, and extending over the fronded concrete mattress border, wherein the export cable rests among and between fronds extending from fronded concrete mattress border.

7. The system of claim 5, wherein the single-layer gravity-based protection comprises: a rock blanket, wherein the rock blanket is adapted to be applied on an undersea ground surface, over and around the center of the undersea monument foundation.

8. The system of claim 5, wherein the fronded concrete mattress border comprises: a plurality of fronded concrete mattresses, wherein the plurality of fronded concrete mattresses is adapted to be positioned around the periphery of the single-layer gravity-based protection to form a peripheral ring on, over, and around an edge of the single-layer gravity-based protection at a border of the single-layer gravity-based protection and a ground surface of the undersea ground.

9. A method adapted for use in protecting an undersea monument foundation against undersea scour, the method comprising: preparing an undersea ground surface at an intended site of an undersea monument foundation; applying a single-layer gravity-based protection to a central area of the undersea ground surface at the intended site of the undersea monument foundation; and installing a fronded concrete mattress border covering and surrounding a periphery of the single-layer gravity-based protection; wherein installing the fronded concrete mattress border is adapted to position the fronded concrete mattress border below and to support any export cable exiting a monument positioned on a foundation installed at the intended site, and wherein a plurality of fronds of the fronded concrete mattress is adapted to engage and shelter the export cable supported on the installation.

10. The method of claim 9, the method further comprising: Installing the export cable extending from the undersea monument foundation, extending over the single-layer gravity-based protection, and extending over the fronded concrete mattress border, wherein the export cable rests among and between fronds extending from fronded concrete mattress border.

11. The method of claim 9, wherein the single-layer gravity-based protection comprises: a rock blanket, wherein the rock blanket is adapted to be applied on an undersea ground surface, over and around the center of the undersea monument foundation.

12. The method of claim 9, wherein the fronded concrete mattress border comprises: a plurality of fronded concrete mattresses, wherein the plurality of fronded concrete mattresses is adapted to be positioned around the periphery of the single-layer gravity-based protection to form a peripheral ring on, over, and around an edge of the single-layer gravity-based protection at a border of the single-layer gravity-based protection and a ground surface of the undersea ground.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] By reference to the appended drawings, which illustrate exemplary embodiments of this invention, the detailed description provided below explains in detail various features, advantages, and aspects of this invention. As such, features of this invention can be more clearly understood from the following detailed description considered in conjunction with the following drawings, in which the same reference numerals denote the same, similar, or comparable elements throughout. The exemplary embodiments illustrated in the drawings are not necessarily to scale or to shape and are not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments having differing combinations of features, as set forth in the accompanying claims.

[0022] FIG. 1 shows a side elevation cross-sectional view of a simplified depiction of an exemplary embodiment of a system, according to aspects of the invention, such as an offshore monopile foundation protected by an AESPS.

[0023] FIG. 2 shows a plan view of the simplified depiction of the exemplary embodiment of the system in FIG. 1, according to aspects of the invention.

[0024] FIG. 3 shows a side elevation cross-sectional view of the simplified depiction of the exemplary embodiment of the system in FIG. 1, with an exemplary in-place fronded eco-concrete mattress and an export cable buried by a subsequently-formed sediment protection layer, according to aspects of the invention.

[0025] FIG. 4 shows a side elevation cross-sectional view of the simplified depiction of the exemplary embodiment of the system in FIG. 1, with a fronded eco-concrete mattress before releasing fronds, according to aspects of the invention.

[0026] FIG. 5 shows a side elevation cross-sectional view of the simplified depiction of the exemplary embodiment of the system in FIG. 4, with the fronded eco-concrete mattress after releasing fronds, according to aspects of the invention.

[0027] FIG. 6 shows a block diagram of an exemplary embodiment of a method for use in protecting an undersea monument foundation against undersea scour, for use within a system and/or apparatus in accordance with exemplary embodiments of the present invention, according to aspects of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0028] The invention relates to systems, methods, and apparatus involving scour protection of undersea foundations, and an exemplary embodiment of the invention may be referred to as an Advanced Ecological Scour Protection System (AESPS).

[0029] The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures are identified with the same reference numerals. Reference will now be made in detail to each embodiment of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto.

[0030] It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Also, the exemplary embodiments presented below maybe combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.

Exemplary Embodiments of a System

[0031] A preferred exemplary embodiment of an Advanced Ecological Scour Protection System (AESPS) may comprise two main features to enhance the foundation stability and the nearby eco-productivity. The first feature may include a single application layer rock blanket, applied on an undersea ground surface, over and around an intended foundation site. The second feature may include a fronded concrete mattress border, formed as a peripheral ring on, over, and around an edge of the rock blanket at a border of the rock blanket and the undersea ground surface.

[0032] The single-layer rock blanket is an example of a gravity-based protection of a central area, and in the preferred embodiments, the central area uses rocks in a single layer applied in a single application to form the gravity-based rock blanket. However, in other embodiments, the central area gravity-based protection need not necessarily to be a rock blanket or have a blanket shape; rather, it can be loose rock materials, blankets, rigid covers, or any other preferred structural types decided by a project team. In such other embodiments, the choice of gravity-based protection of the central area preferably still allows the central area protection to be applied before the foundation is installed through the central area protection. In such other embodiments, a gravity-based cover may be selected that enhances the dynamic stability of the seabed, wherein any gravity-based cover that improves the (a) relative density of sediment; (b) bed roughness; (c) sediment diameter; and/or (d) sediment friction angle, will enhance the dynamic stability of the seabed. Therefore, alternative options such as riprap rock, rock bag, engineering cover, or artificial recycled materials can all serve the purpose. The decision regarding the choice of gravity-based protection preferably will be based on considerations of (a) material cost; (b) material accessibility within the region; and (c) constructability and installation complexity. Regarding complexity, it is worth noting that loose materials typically are less complex and can be deployed easily by barges, whereas engineering-tailored materials or structures typically are more complex and potentially could require advanced offshore installation equipment, such as a heavy-duty crane, ROV, subsea ultrasonic sensor, etc., that may limit, restrict, or prevent application of a more-complex solution within large water-depth zone.

[0033] As used herein, a single-application layer and a single layer are related terms that refer to a layer of material (e.g., rocks) applied to form a single layer, preferably applied uninterrupted in a single application process, in which the single layer may comprise a layer of rocks that may be several rocks deep, and may comprise rocks of various materials, shapes, and sizes applied to form the single layer. In some embodiments, a single layer could include applying a first layer of rocks of a first rock type, followed by applying a second layer of a second rock type, such as wherein the rocks of the second rock type may fill in gaps existing between rocks of the first rock type in the first layer.

[0034] Embodiments of the present invention offer various advantages over prior art systems. Application of a single-application layer rock blanket or other equivalent gravity-based materials lowers the requirement for transportation, installation, and construction monitoring. There is no specific requirement for the exact units/materials to be used for central area. The fronded mattress is introduced along the edge of the single layer zone, which significantly reduces various risks, such as have been observed in the North Sea, such as edge scouring, broken or missing cables, and material loss. The fronded mattress provides a suitable cable lateral support system, while not requiring any additional underwater support, remotely-operated vehicle (ROV), cable cover, or specific placement of the cable, thereby avoiding any long-term premature failure, and minimizing installation time and expense. Depending on the selection of central materials, the connection between the central zone units, of the single layer, and the circumference units, of the fronded eco-mattress, could vary between overlapping and soft linking or pre-assembling. The usage of an eco-friendly concrete materials and shapes for the fronded mattress encourages the development of underwater communities.

Drawings of Exemplary Embodiments of the Invention

[0035] Referring to the Figures, the Figures depict an exemplary undersea ground surface setting according to the present invention, in which a depicted scour protection system may employ an exemplary method to protect a monopile foundation against undersea scour. The depicted system may employ the depicted method to prepare an undersea ground surface at and around an intended site of a monopile foundation, such as clearing and/or cleaning the surface to receive a foundation; to use a single-application layer rock blanket to cover and reinforce the surface; and to install a fronded concrete mattress border on, at, and around a periphery of the rock blanket, before installing the monopile foundation and an export cable, such as from a wind-powered generator erected on the monopile foundation.

[0036] The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures are identified with the same reference numerals. Reference will now be made in detail to each embodiment of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto.

[0037] Referring to FIG. 1, FIG. 1 shows a side elevation cross-sectional view of a simplified depiction of an exemplary embodiment of a system 10000, according to aspects of the invention, such as an offshore monopile foundation protected by an AESPS, with the general arrangement of AESPS around a monopile foundation. A user 10001 may design, install, operate, and/or maintain the system 10000. As depicted in FIG. 1 and FIG. 2, the system includes a monopile 10011 at a center, surrounded by an application of a single layer rock blanket 10012, and encircled by an installation of fronded concrete mattress units 10013. Exiting and extending from the monopile 10011 is an export cable 10017 that rests on an upper surface of the fronded concrete mattress installation 10013. The lateral extension of the AESPS scour protection is a function of a diameter of the monopile 10011, the designed scour depth, and the friction angle of the seabed soil. The ratio between the width of single layer rock blanket 10012 and the width of fronded eco-mattress installation 10013 may allow some level of flexibility according to specific site conditions and project requirements, given that the former is a compromise of budget control. The external cable 10017, as depicted, lays across the fronded zone of the fronded mattress installation 10013, getting supported laterally and vertically with the growing sediment 10018 in the area.

[0038] Referring to FIG. 2, FIG. 2 shows a plan view of the simplified depiction of the exemplary embodiment of the system in FIG. 1, according to aspects of the invention. With the use of the fronded mattresses installation 10013, which extends from the fronded mattress inner boundary 10013 and overlaps the outer rock blanket boundary 10012, the system 10000 provides improved diversion of the current flow, such that the scour system 10000 may cover a smaller area than that of conventional scour systems currently used today. This decreased footprint will decrease the overall impact of the foundation systems for the offshore wind development. The smaller size will offset the anticipated higher cost of each fronded mattress 10007, having the overall scour system 10000 be cost-competitive with a typical scour system used today.

[0039] Referring to FIG. 3, FIG. 3 shows a side elevation cross-sectional view of the simplified depiction of the exemplary embodiment of the system 10000 in FIG. 1, with an exemplary in-place fronded eco-concrete mattress 10007 and an export cable 10017 buried by a subsequently-formed sediment protection layer 10018, according to aspects of the invention. The fronded mattress installation 10013 may include multiple fronded eco-concrete mattress units 10007 interconnected by connections 10010 to reduce movement and shifting of the units 10007 with respect to each other and to the monopile 10011. Fronds 10008 are depicted as floating upward from the fronded mattress units 10007, with the accumulated sediment layer 10018 having accumulated among and between the fronds 10008, and over the cable 10017 lying among and between the fronds 10008. Over time, after installation of the system 10000, sea life 10006 may attach to and accumulate on the fronded mattress units 10007, further promoting the natural environment and enhancing the biodiversity of the installation site.

[0040] FIG. 3 closely exhibits the in-place status of the edges of an AESPS 10000, where the fronded eco-mattress installation 10013 either links to or overlaps the boundary of single layer rock blankets 10012. The fronded design would be such that the export cable 10017 could be installed after the mattress installation 10013 was in place, and the cable 10017 would be able to rest between or within the fronds 10008. The fronded design would have fronds 10008 of sufficient lateral stiffness to hold the cable 10017 in place. The fronds 10008 would both divert localized current flow, decreasing the load on the cable 10017, as well as provide lateral support to prevent or limit lateral movement of the cable 10017.

[0041] Another key benefit of the fronded eco-mattresses 10007 is that they are to be designed and manufactured in such a way that a vessel capable of deploying the rock blanket 10012 could also deploy the fronded mattress units 10007. Even, if this dual use is not possible in a given installation and a second vessel is needed, the full scour projection system 10000 could be deployed in advance of the foundation installation with no follow up deployments required. Once installed, the scour projection system 10000 would therefore be removed from the monopile installation project's critical path timeline.

[0042] The eco-mattresses 10007 may comprise concrete that has been developed to be beneficial to marine life. In particular, a chemical composition of the cement and resulting concrete may use additives to improve the pH of the concrete and provide suitable substrates for sea life 10006, in particular such as for marine mollusks to adhere to. In addition, the individual concrete elements 10007 may be designed with surface features to maximize marine life use and habitat.

[0043] Referring to FIG. 4, FIG. 4 shows a side elevation cross-sectional view of the simplified depiction of the exemplary embodiment of the system 10000 in FIG. 1, with a fronded eco-concrete mattress 10007 before releasing fronds 10008, according to aspects of the invention. Also depicted in FIG. 4 are concrete segment joints 10003 that interconnect concrete segments of the mattress 10007 and preferably permit flexibility of the fronded mattress 10007. The mattress unit 10007 also is depicted as including an interconnection device 10004, such as a metal loop or hook, to interconnect and adjoin one mattress unit 10007 with an adjacent adjoining fronded mattress unit 10007, to be adjoined to another fronded mattress unit 10007 by a connection joint 10010. Prior to and during installation of the mattress unit 10007, the fronds 10008 preferably are covered by a fronds cover 10009, which preferably is a fast-release cover that may be removed easily and quickly once the system 10000 is installed and the monopile foundation 10011 is installed and ready.

[0044] Referring to FIG. 5, FIG. 5 shows a side elevation cross-sectional view of the simplified depiction of the exemplary embodiment of the system in FIG. 4, with the fronded eco-concrete mattress 10007 after releasing fronds 10008, and after removing any fronds cover 10009, according to aspects of the invention. Also depicted in FIG. 5 is an adjacent adjoining fronded mattress unit 10007, adjoined to another fronded mattress unit 10007 by a connection joint 10010, preferably fabricated and made of eco-friendly materials.

[0045] FIG. 4 and FIG. 5 present, respectively, the in-transit and in-place status of the fronded eco-concrete mattress 10007. During the transportation, the self-buoyant frond lines 10008 may be folded airtightly and may be covered by one or more top sheets 10009 to prevent potential damage. Once a frond mattress 10007 is lowered and placed on the seabed, a diver or ROV can remove the cover sheet 10009, such as by unlocking any locks along the sides, and can retrieve the cover sheet 10009 to the vessel. The fronded lines 10008, made of buoyant polyester, will then float and create a condense flow-barrier around the monopile foundation 10011, attracting and supporting marine habitats and marine life 10006 within the area.

[0046] Referring to FIG. 6, FIG. 6 shows a block diagram of an exemplary embodiment of a method 60000 for use in protecting an undersea monument foundation 10011 against undersea scour, for use within a system 10000 and/or apparatus in accordance with exemplary embodiments of the present invention, according to aspects of the invention. The method 60000 may begin with an optional step 61000 to prepare an undersea ground surface at and around an intended site of a monopile foundation 10011, such as clearing and/or cleaning the surface to receive a foundation 10011. The method 60000 may proceed to step 62000 to apply a single-layer rock blanket 10012, such as a single-application layer rock blanket 10012, to cover and reinforce the surface. The method 60000 may proceed to step 63000 to install a fronded concrete mattress border 10013 on, at, and around a periphery of the rock blanket 10012, before installing the monopile foundation 10011 and an export cable 10017, such as from a wind-powered generator erected on the monopile foundation 10011. The method 60000 optionally may proceed to optional step 64000 to install the monopile foundation 10011 and corresponding monopile, followed by optional step 65000 to install any export cables 10017.

[0047] The foregoing description discloses exemplary embodiments of the invention. While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims. Modifications of the above disclosed apparatus and methods that fall within the scope of the claimed invention will be readily apparent to those of ordinary skill in the art. Accordingly, other embodiments may fall within the spirit and scope of the claimed invention, as defined by the claims that follow hereafter.

[0048] In the description above, numerous specific details are set forth in order to provide a more thorough understanding of embodiments of the invention. It will be apparent, however, to an artisan of ordinary skill that the invention may be practiced without incorporating all aspects of the specific details described herein. Not all possible embodiments of the invention are set forth verbatim herein. A multitude of combinations of aspects of the invention may be formed to create varying embodiments that fall within the scope of the claims hereafter. In addition, specific details well known to those of ordinary skill in the art have not been described in detail so as not to obscure the invention. Readers should note that although examples of the invention are set forth herein, the claims, and the full scope of any equivalents, are what define the metes and bounds of the invention protection. The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others or ordinary skill in the art to understand the embodiments disclosed herein.

[0049] When introducing elements of the present disclosure or the embodiments thereof, the articles a, an, and the are intended to mean that there are one or more of the elements. Similarly, the adjective another, when used to introduce an element, is intended to mean one or more elements. The terms including and having are intended to be inclusive such that there may be additional elements other than the listed elements.

[0050] Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.