Anchoring floating structures to the water bottom

Abstract

In general terms, the anchor includes a tubular body made at least in part from a cementitious material and having an open end and a closed end. The anchor further includes a pad eye coupled to the tubular body and configured to couple to a mooring line. The tubular body has a bottom wall, a peripheral wall, and a shear key. The bottom wall defines the closed end of the tubular body, the bottom wall having first and second surfaces on opposite sides of the bottom wall. The peripheral wall extends from the first surface of the bottom wall to the open end of the tubular body, and the shear key extends from the second surface of the bottom wall. The shear key penetrates the water bottom and, once penetrated, resists lateral displacement of the anchor along the water bottom.

Description

[Technical Field]

[0001] The following description relates to anchoring a floating structure to the subsurface floor (bottom).

[0002] [Citation of Related Applications] This application claims priority from U.S. Provisional Patent Application No. 63 / 400,656, entitled "Anchoring Floating Structure to an Underwater Floor," filed August 24, 2022, which is incorporated by reference in its entirety. [Background technology]

[0003] Anchors may be used to secure or restrain the location of floating objects on water (sea). To do this, anchors may be deployed on the subsurface, i.e., bottom of the water (including the seabed, lakebed, riverbed, etc.), and connected to the floating object by a cable, rope, or chain. The anchor may use its mass to remain stationary on the bottom of the water, thereby creating tension in the connection that restrains the movement of the floating object. In certain cases, multiple anchors may be used to apply multiple restraining forces to the floating object. The presence of multiple anchors can help reduce the risk of one or more connections breaking. The presence of multiple anchors may also limit the floating object's drift around the desired installation location. Summary of the Invention

[0004] In general terms, the anchor includes a tubular body made at least in part from a cementitious material and having an open end and a closed end. The anchor further includes a pad eye coupled to the tubular body and configured to couple to a mooring line. The tubular body has a bottom wall, a peripheral wall, and a shear key. The bottom wall defines the closed end of the tubular body, the bottom wall having first and second surfaces on opposite sides of the bottom wall. The peripheral wall extends from the first surface of the bottom wall to the open end of the tubular body, and the shear key extends from the second surface of the bottom wall. The shear key penetrates the water bottom and, once penetrated, resists lateral displacement of the anchor along the water bottom. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a schematic perspective view of an exemplary floating photovoltaic system anchored to the bottom of the water by mooring lines. [Figure 2A] 1 is a schematic perspective view from above of an exemplary anchor for securing a floating structure to the bottom of a body of water; FIG. [Figure 2B] 2B is a schematic perspective view from below of the exemplary anchor of FIG. 2A, with portions thereof shown in partial perspective; FIG. [Figure 2C] 2B is a schematic perspective view from below of the exemplary anchor of FIG. 2A, showing the exemplary anchor having a shear key with a peripheral wall and four straight walls. FIG. [Figure 3] 10 is a schematic diagram illustrating another configuration of a shear key. [Figure 4] FIG. 1 is a schematic perspective view of an exemplary anchor manufactured at least in part using a 3D printing method. [Figure 5] 1 is a schematic elevation view of an exemplary anchor having a body with ribs and a patterned surface printed thereon. FIG. [Figure 6] FIG. 1 is a schematic elevation view of an exemplary tension leg platform supporting a wind turbine and secured to the water bottom using nine anchors. [Figure 7A] FIG. 1 is a schematic top perspective view of an exemplary anchor having a tubular body and a pad eye. [Figure 7B]7B is a schematic perspective view of the exemplary anchor shown in FIG. 7A, viewed from below. FIG. [Figure 7C] 7B is a schematic cross-sectional view of the exemplary anchor of FIG. 7A. [Figure 7D] 7D is a schematic top perspective view of the exemplary anchor of FIG. 7D, but showing the exemplary anchor with a lid covering the open end of the exemplary anchor. [Figure 8] FIG. 7B is a schematic side view of the exemplary anchor of FIG. 7A, showing the exemplary anchor with a dome-shaped lid. [Figure 9] FIG. 1 is a schematic top perspective view of an exemplary anchor having multiple stiffening walls. DETAILED DESCRIPTION OF THE INVENTION

[0006] In general terms, the anchor is described as for securing a floating structure to the waterbed. The floating structure may be, for example, a renewable energy structure, such as a floating solar energy system, a wave energy system, and a wind energy system in a freshwater or saltwater body (e.g., inland or offshore). In some embodiments, the anchor is used to secure floating solar energy systems, which may have mooring loads that are one or two orders of magnitude lower than floating wave energy and wind energy systems (e.g., 15 tons holding capacity versus 1500 tons).

[0007] Mooring and anchoring are key system and application challenges, for example, in the development of reliable, low-cost floating photovoltaic (FPV) panels and other types of systems. FPV systems can be mounted on floating pontoons (barges) that hold the photovoltaic (PV) panels in place with mooring lines connected to anchors. Figure 1 is a schematic perspective view of an exemplary FPV system, where the FPV system is anchored to the bottom of the body of water by mooring lines. Deploying photovoltaic panels over a body of water offers solar energy opportunities where ground-mounted or rooftop systems are limited or unavailable.

[0008] FPV systems may be anchored using concrete blocks (dead weight / gravity bodies), helical anchors, or driven piles. However, these anchors have their own deployment limitations. For example, helical anchors generally require a drive unit to place the helical anchor below the water surface, making such helical anchors useful only in narrow soil sections. Steel piles often require expensive heavy equipment to install. Concrete gravity anchors work in wide soil section conditions and are quick to install, but their crude shape makes such anchors heavy and requires a lot of material.

[0009] As an example, an FPV system may use 10 to 30 conventional block anchors per megawatt, each weighing 2 to 5 tons and costing $350 to $500 per ton. Thus, a typical 10 MWp plant may use 700 tons of concrete, costing approximately $300,000. This large amount of concrete can be difficult to handle, necessitating the fabrication of custom pontoons on-site for the installation of concrete block anchors. Furthermore, each block is significantly over-engineered due to its limited horizontal load capacity, which is approximately one-third of its vertical capacity. Such over-engineering is also required to mitigate the risk of improper mooring, as anchoring failure can result in catastrophic system failure and damage, sometimes resulting in total unavailability.

[0010] The anchors described herein may provide advantages over conventional anchors. For example, the anchors described herein may reduce cost, increase efficiency, simplify manufacturing and construction, and increase mechanical stability and functionality. Other advantages may be realized.

[0011] In some embodiments, the anchors described herein have a "stubby" (high aspect ratio) body that utilizes the mass of the anchor structure during deployment to secure the floating structure to the water bottom. In some variations, the anchor further includes a suction chamber that provides suction during deployment. The suction can help the anchor's mass secure the anchor to the water bottom. In these variations, the anchor may represent a hybrid anchor. In some embodiments, the anchor lacks a fluid port (e.g., for generating suction within the suction chamber), allowing the anchor body to have a simple structure. However, the anchor can still benefit from suction generation during short periods of high dynamic loads, such as during inclement weather. The anchor may be made of cementitious materials (e.g., concrete, reinforcing elements, aggregates, etc.). In some variations, the anchors have features that reduce the amount of cementitious material or reinforcement required for their fabrication. Such weight reduction can reduce the cost of the anchor and reduce greenhouse gas emissions during the manufacture of the cementitious material.

[0012] Additional features and advantages of the anchor may include one or more of the following: (1) the ability to use low-cost (and low-carbon intensity) ballast materials (e.g., local aggregates, recycled concrete, or other waste materials) in the body of the anchor; (2) corrugated or undulating walls to increase the stiffness and strength of the walls that make up the body of the anchor; (3) reinforcement for co-location locations of pad eyes, body floor (e.g., bottom wall), and shear key orientation to reduce the amount of reinforcement; (4) fillets or cavities incorporated into the anchor floor to reduce stress concentrations and reduce the amount of concrete and reinforcement; (5) closed shear keys to create suction; (6) shear key shapes positioned to support ballast weight on the body floor (e.g., bottom wall); and (7) shear key shapes with a profile that increases the torsional resistance of the anchor. Other features and advantages are also contemplated.

[0013] FIG. 2A provides a schematic diagram, from a top perspective view, of an exemplary anchor for securing a floating structure, such as an FPV system, to the bottom of a body of water. The exemplary anchor can include one or more of the features and advantages described above. As shown in FIG. 2A, the exemplary anchor includes a shear key, a bottom wall, one or more pad-eye connections, a body wall (e.g., a perimeter wall), and a lid. In many variations, the anchor components are manufactured using additive manufacturing techniques, such as 3D concrete printing. However, other manufacturing techniques are possible, including combinations of the above methods. Other possible manufacturing techniques include 3D casting (which can 3D print stayform walls into which concrete material is poured), concrete spraying, precasting, casting, and slip molding. The exemplary anchor can use gravity—and, in some configurations, suction—to resist vertical and roll forces. The example anchor may also use friction or bearing forces to withstand horizontal forces applied by the mooring line to one or more pad eyes of the example anchor. In some embodiments, the example anchor is connected to a single mooring line. In some embodiments, the example anchor is connected to multiple mooring lines, for example, in a shared anchor configuration, to reduce the number of anchors required.

[0014] During installation, one or more shear keys of the example anchor are partially or fully embedded below the water bottom to increase the load-bearing capacity of the example anchor. The shear keys can take a variety of shapes, including open or closed profiles. FIG. 2A shows an example of a shear key in which the shear key has a closed profile. The shear keys can increase the vertical load-bearing capacity and roll-over resistance of the example anchor. The shear keys can also increase the horizontal load-bearing capacity of the anchor. These increases can be caused by pressure differentials in the example anchor (e.g., pressure differentials between the inside and outside of the example anchor) that occur when the example anchor is lifted or rotated about a horizontal axis.

[0015] FIG. 3 is a schematic diagram illustrating alternative configurations 300a-300f for a shear key 300. (These configurations are shown in a reduced scale for illustrative purposes.) In this diagram, six example anchors are shown, each oriented "upside down" so that its shear key 300 is in a supine position. The shear key 300 of the example anchor may have one or more walls extending outward from a surface 304 of a bottom (or base) wall 306. For example, the shear key 300 may have a peripheral wall 302 extending outward from the surface 304 of the bottom wall 306. The peripheral wall 302 may be of various shapes, such as circular in the case of peripheral walls 302a-302d or star-shaped in the case of peripheral wall 302e. In some variations, shear key 300 has a second wall, such as concentric circular wall 308 of shear key 300d, fitted within peripheral wall 302. In some variations, bottom wall 306 defines a closed end for the tubular body of the example anchor (see, e.g., shear key 300f). In these variations, peripheral wall 302 may be configured to convert the closed end to an open end (see, e.g., shear keys 300a-300e). For example, peripheral wall 302 may extend outward from surface 302 sufficiently to define an opening into a cavity in the tubular body. The cavity may, in some cases, be configured to be a suction chamber of the example anchor. For example, peripheral wall 302c of shear key 300c may define a cavity deep enough to function as suction chamber 310. The suction chamber 310 may be fluidly coupled to the exterior of the exemplary anchor via a conduit, and an example of such a configuration is described with reference to Figures 7A-7D.

[0016] Multiple walls may be used to increase the support capacity of the shear key. The exemplary anchor may also have a stiffening wall located within the interior cavity to provide additional rigidity and strength to the bottom wall of the exemplary anchor, thereby enabling the use of a thinner, more efficient floor structure that reduces material used during construction. For example, the material used to construct the floor structure may be reduced by approximately 50% compared to a solid floor slab. In some variations, the shear key may be profiled with teeth to increase the torsional resistance of the exemplary anchor. The teeth may also stiffen the shear key, thereby reducing material and reinforcement to be used during construction. In some variations, the shear key may have a peripheral wall extending from the bottom wall and defining the open end of the exemplary anchor. The peripheral wall may be referred to as a "skirt" and may contribute to scouring the bottom of the water from below the exemplary anchor. In some cases, such as that shown in FIG. 2A, the peripheral wall defines a portion of the outer periphery of the exemplary anchor.

[0017] In some embodiments, the shear key can provide additional mass to resist mooring loads. The body of the exemplary anchor can have a bottom wall, as shown in the bottom perspective view of FIG. 2B, and pad eyes or hoisting connections can be added to the shear key and connected to the bottom wall. For clarity, the internal shear key is omitted from FIG. 2B to better view the reinforcing material (e.g., rebar). The body can be hollow or solid. In some variations, the body has a peripheral wall defining a tubular structure. The body can further include a hollow chamber to facilitate the addition of low-cost, locally sourced ballast material, such as sand, stone, or recycled concrete. The bottom wall can house a reinforcing cage that transfers mooring loads from the pad eyes to the body and shear key. In some configurations, bottom wall reinforcement can extend into the shear key and its walls to provide reinforcement to these portions of the exemplary anchor. Other reinforcing materials that can be used include random fibers, cables, tendons, or staples. The reinforcing material can be part of the cementitious material. Figure 2C shows an embodiment of the example anchor of Figure 2A, where the example anchor has a shear key that forms the anchor skirt. The shear key has four straight walls that intersect with the anchor floor to define the suction chambers (e.g., nine suction subchambers) of the example anchor.

[0018] The profile of the body can take on a variety of shapes, including cylindrical, triangular, rectangular, or some other type of shape (e.g., truncated). For example, the body can be cylindrical in shape, with a corrugated or sinusoidal circumferential wall increasing the stiffness of the body compared to a smooth wall. The corrugated or sinusoidal circumferential wall can also increase the strength of the circumferential wall, thereby reducing the amount of material required to manufacture the wall. As another example, the body can be triangular in shape and configured so that the mooring line can be connected to the midpoint of the base of the triangle. This shape and configuration can provide good rollover resistance by locating the pad eye connection point near the center of gravity of the body. In some cases, ribs can be printed into the body to form stiffening walls that increase the stiffness and strength of the body. FIG. 5 is a schematic elevation view of an example anchor having a body with ribs and a textured surface printed thereon.

[0019] In some embodiments, the example anchor may have a lid that forms an enclosure for the body and prevents loose ballast material (e.g., sand) from escaping from the body. In some embodiments, a lid may be used on the body to create a buoyancy chamber to aid in placement of the example anchor, especially for very large, high-capacity anchors. The buoyancy chamber, if unfilled, allows the example anchor to float when placed on water. However, in some constructions, the body is substantially entirely filled with material to maximize the mass of the example anchor.

[0020] In many variations, the lid may have a textured surface resembling shapes found in nature, such as starfish or cavities that provide a protective habitat for marine life. The textured surface may be formed, for example, by undulating walls on the lid. In this manner, the lid may encourage the growth of marine life, supporting the marine ecosystem and allowing additional organic matter to grow on the anchor. However, other lid shapes are possible, such as lids with smooth surfaces or lids that partially enclose the body. For example, the lid may be in the form of a net filled with large ballast material, such as large rocks. Alternatively, the thickness of the lid may be increased to allow additional objects to rest on top of the anchor. As another example, the lid may be in the form of a basket that can be filled with additional ballast to further increase the mass of the exemplary anchor. This additional mass may increase the downward force on the shear key, thereby aiding in the installation of the exemplary anchor on a hard seabed. In some variations, the lid may have a hoisting ring to aid in the installation and removal of the lid. Additionally, the lid may be designed to rest on top of the body or on a lip just below the surface of the body to facilitate positioning and placement of the lid on the anchor. The lid may also be fastened to the body using fasteners or other reinforcing materials. The lid may also be configured to accept an adhesive (e.g., grout, epoxy, etc.) for fastening.

[0021] In some embodiments, the exemplary anchor may have features (1) through (6). (1) The body may include a shear key combined with the use of ballast material. The shear key may have a closed profile that creates suction, thereby increasing the vertical load and rollover resistance of the exemplary anchor. (2) The body may also have a large aspect ratio (e.g., approximately 1:1 height to length) that maximizes the amount of ballast material in the body relative to the amount of cementitious structural material. The body's wide footprint may also provide significant rollover resistance. (3) One or more pad eyes are incorporated into the body's floor, e.g., the bottom wall or a portion of the perimeter wall located near the bottom wall. Other body placement locations are possible. This incorporation also allows for the incorporation of reinforcing material into the floor or body, which may help withstand mooring loads on the pad eyes and the load of ballast material on the bottom wall. (4) Reinforcement is provided in the body's floor, which may extend through the shear key, bottom wall, and perimeter wall. (5) The shape and location of the shear key walls may be designed to maximize the stiffness of the example anchor while reducing the amount of concrete material required to fabricate the bottom wall. (6) Anchor transportation and installation methods may be implemented that are easily scalable to larger anchor sizes. For example, for very large and heavy anchors, the body—which may be hollow—may be transported floating, without ballast, to the installation site and then lowered to the water bottom using a small crane (e.g., before ballast is added to the example anchor). Any combination of these features is possible for the example anchor.

[0022] The exemplary anchor may further include features that facilitate its manufacture. For example, the perimeter wall, bottom wall, and shear key may be fabricated using 3D printing, 3D casting, or 3D spraying techniques to aid in the incorporation of reinforcing materials. In particular, 3D casting techniques enable the use of recycled concrete in concrete mixes or large-diameter (e.g., up to ¾ inch (approximately 2 cm) diameter) aggregates, which are low-cost and have low carbon dioxide emissions and would otherwise be difficult to print or spray through small-diameter hoses or nozzles. As another example, the amount of cementitious material used to form the bottom wall may be reduced by using blockout material or stay forms to create the shear key and fillet surfaces of the body. Furthermore, fabricating the anchor shell at an off-site printing facility allows for the shipping of a lightweight anchor assembly that can be filled with locally sourced ballast material at the installation site. The anchor shell may be part of the body of the exemplary anchor.

[0023] Various methods can be used to manufacture the exemplary anchor. For example, additive manufacturing can be used to manufacture the exemplary anchor in multiple layers that can be cured and optionally repositioned, turned over, or receive a pourable material. Additive manufacturing can also be used to manufacture the exemplary anchor without first having to create a supporting frame structure. Furthermore, 3D printed material can be added to the body of the exemplary anchor after the exemplary anchor has cured for a period of time.

[0024] In some embodiments, a method for manufacturing an anchor, such as the exemplary anchor described with reference to FIGS. 2A-2C, includes 3D printing the contours of the shear key (or its walls) and the bottom wall. The contours may be referred to as stay forms. The method includes inserting shielding material (e.g., sand or foam), reinforcing material (e.g., non-corrosive rebar), and pad-eye connections (e.g., concrete or metal loops) into or around the stay forms. The shielding material can create voids in the concrete structure to reduce material usage if no concrete material is required. The method further includes pouring concrete material into or around the stay forms and allowing the assembly (or as-fabricated body) to cool. In many embodiments, the method includes printing the walls (e.g., perimeter walls, stiffening walls, etc.) of the anchor body onto the bottom wall. FIG. 4 is a schematic perspective view of an exemplary anchor manufactured at least in part using a 3D concrete printing method.

[0025] The anchors described herein may also provide advantages associated with their design and manufacture. These advantages may be associated with digital design-additive manufacturing methods, which may include parametric design software combined with additive manufacturing methods. The digital design process allows various configurations of the anchor to be rapidly and cost-effectively manufactured and installed without creating a new frame structure. These configurations may include different anchor sizes, various shapes of bodies, shear keys, and surface textures, and may include configurations installed in solar thermal plants or FPV systems. Furthermore, modeling software allows for rapid variation of the anchor design to accommodate various input assumptions, and the resulting designs can be rapidly printed. Digital design and additive manufacturing methods may provide the opportunity to optimize the design of each anchor for the required holding capacity, thereby improving the overall material efficiency of the anchor at the plant level. This improvement may reduce over-design of the anchor resulting from the typical use of a limited number of different molds.

[0026] The 3D printing process associated with pre-designed anchors is often extremely quick and cost-effective due to the lack of frame construction and labor savings in manufacturing. In some specific cases, anchors for FPV systems take approximately 20 minutes to print with one or two people operating the printer.

[0027] Lightweight anchor shells can be manufactured in various locations, for example, in off-site facilities within existing concrete manufacturing facilities using automated methods. The manufactured shells can then be cost-effectively shipped to the installation site and then filled with ballast. Implementation of off-site construction methods can result in high quality anchors due to a sheltered and more consistent manufacturing environment. If higher anchor quantities, larger sizes, or shorter shipping distances are required, anchors can also be manufactured locally (e.g., on-site).

[0028] Furthermore, as floating wind technology advances, anchor configurations can be scaled up and deployed for moored offshore wind turbines. In some configurations, a key advantage of suction anchors is that their mass can withstand vertical loads. For example, the mass of a suction anchor can withstand the average vertical load generated by a floating wind turbine substructure, such as a tension leg platform (TLP). Thus, suction anchors can withstand large vertical forces in some cases. Deployment in deep water (approximately 1000 m) may require a TLP design that includes short, relatively environmentally friendly mooring lines, as shown in FIG. 6. Additionally, TLP designs are arguably the most stable platform designs in large waves. The anchors described herein are particularly advantageous because, in many cases, they can provide both suction and gravity attachment to the water bottom. Furthermore, the anchors are scalable in size, allowing the anchors to be transported floating to their installation site. For example, while floating, the anchors can be oriented vertically in the same direction as the installation direction and then inexpensively sunk using small vessels. Anchors can provide advantages with respect to other floating wind turbine substructures, such as semi-submersible or pontoon platforms, which can use various mooring configurations, such as taut, semi-taut, or loose mooring configurations. Anchors can provide advantages with respect to other mooring configurations that share mooring lines between wind turbines or anchors between multiple mooring lines.

[0029] In some variations, for example in TLP designs, the pad eyes of the anchor can be connected directly to the bottom wall to directly withstand the ballast load and keep the concrete in the anchor out of tension. Alternatively, the pad eyes can be connected to the perimeter of the anchor near the perimeter of the body, the lid, or the bottom wall.

[0030] Referring now to Figure 7A, a schematic top perspective view of an exemplary anchor 700 is shown, including a tubular body 702 and a pad eye 704. The pad eye 704 is coupled to the tubular body 702 and configured to couple to a mooring line. Figures 7B and 7C are bottom perspective and cross-sectional views, respectively, of the exemplary anchor of Figure 7A. The cross-sectional view of Figure 7C is taken about a midplane 706 through the exemplary anchor 700.

[0031] The tubular body 702 is formed at least in part from a cementitious material, and has an open end 708 and a closed end 710. The cementitious material may include cement and aggregate (e.g., sand or gravel). In some cases, the cementitious material may further include reinforcing elements, such as fibers (e.g., steel fibers, polymer fibers, basalt fibers, fiberglass fibers, etc.), rebar (e.g., steel rebar, basalt rebar, etc.), mesh (e.g., steel mesh, fiber mesh, etc.), cables, tendons, staples, etc. The tubular body 702 has a bottom wall 712 that defines the closed end 710 of the tubular body 702, and first and second surfaces 712a, 712b on opposite sides of the bottom wall 712. In some variations, the bottom wall 712 has an exterior surface that forms a portion of the exterior surface of the tubular body 702. In some variations, the bottom wall 712 provides an internal support structure for the tubular body 702, for example, to support ballast material and to provide rigidity to the example anchor 700. In some variations, the pad eye 704 is coupled to a central portion of the first surface 712a of the bottom wall 712. In some variations, such as those shown in Figures 7A-7C, the pad eye 704 is coupled to an exterior side surface of the bottom wall 712, which may form a portion of the exterior surface of the tubular body 702 near the closed end 710.

[0032] The tubular body 702 further includes a peripheral wall 714 extending from a second surface 712a of the bottom wall 712 to an open end 708 of the tubular body 702. The peripheral wall 714 defines an opening at the open end 708 that leads into a cavity 716 in the tubular body 702. In some variations, the cavity 716 is configured to define a volume that, when unfilled, allows the example anchor 700 to float when placed on a body of water. In some variations, the pad eye 704 may be coupled to an edge surface of the peripheral wall near the open end 708. In some variations, the pad eye 704 is coupled to an outer surface of the peripheral wall 714 near the closed end 710 of the tubular body 702 (e.g., adjacent the bottom wall 712).

[0033] The peripheral wall 714, in some cases, may be configured at the open end 708 of the tubular body 702 to receive a lid (e.g., to enclose the cavity 716) that covers the open end 708. For example, the edge of the peripheral wall 714 at the open end 708 may define a lip or rim that the lid fits over to cover the open end 708. FIG. 7D is a schematic top perspective view of the example anchor 700 of FIG. 7A , except that the example anchor 700 includes a lid 717 that covers the open end 708 of the tubular body 702. The lid 717 may have a surface 717a that is configured to face the exterior of the example anchor 700 when it covers the open end 708. One or more features, such as a ripple, wall, bump, etc., may extend from or into the surface 717a. In some variations, such as those shown in FIG. 7D , the lid 717 has a contoured wall 717b that extends from the surface 717a. The undulating wall 717b may define a coral-like pattern on the surface 717a. However, other patterns are possible. In some variations, the lid 717 has one or more pad eyes 704 coupled thereto. While FIG. 7D depicts the lid 717 as having a flat shape, the lid 717 may have other shapes, such as a dome-like shape. The dome-like shape allows the example anchor 700 to hold more ballast material. The dome-like shape may also provide increased surface area, thereby providing space for marine animals to grasp themselves on the lid 717. FIG. 8 is a schematic side view of an example anchor 800 having a dome-like lid 802. The example anchor 800 has a configuration similar to the example anchor 700 of FIGS. 7A-7D, but lacks the conduit 728 and valve 730 of the example anchor 700.

[0034] The tubular body 702 further includes a shear key 718 extending from the second surface 712b of the bottom wall 712. The shear key 718 is configured to penetrate the bottom of the water and resist lateral displacement of the example anchor 700 along the bottom of the water when it penetrates into the submerged wall. In some configurations, the shear key 718 can also resist rotational displacement of the example anchor 700 about the axis 720 of the tubular body 702 when it penetrates into the bottom of the water. The shear key 718 may include one or more walls extending from the second surface 712b of the bottom wall 712.

[0035] For example, the shear key 718 may have a straight wall 722 extending from the second surface 712b of the bottom wall 712. As another example, the shear key 718 may have multiple radial walls (e.g., straight walls 722, curved walls, etc.) extending from the second surface 712b of the bottom wall 712, with each radial wall aligned along a different radial direction extending outward from the center of the bottom wall 712. In some cases, the shear key 718 may have first and second sets of chordal walls extending from the second surface 712b of the bottom wall 712. In these cases, each chordal wall has a chordal end that terminates at the second peripheral wall 712, and the chordal walls of the first set are perpendicular to the chordal walls of the second set. An example of one of these cases is shown in the bottom perspective views of FIGS. 2B and 2C. FIG. 3 illustrates other possible walls for the shear key 718.

[0036] In some variations, the shear key 718 has a second peripheral wall 724 configured to convert the closed end 710 of the tubular body to a second open-ended state, such as that described with respect to shear keys 300a-300e of FIG. 3. In another variation, such as that shown in FIGS. 7A-7D, the second peripheral wall 724 defines an opening into a second cavity 726 of the tubular body 702. The second cavity 726 is configured as a suction chamber of the example anchor 700, and the second anchor 700 has a conduit 728 configured to fluidly couple the suction chamber to an exterior of the example anchor 700. To do so, the conduit 728 may, in some cases, include a valve 730 for controlling the flow of fluid (e.g., water, air, etc.) between the suction chamber and the exterior of the example anchor 700. Other fluid control devices are possible. In some cases, the conduit 728 is defined by a conduit wall of the tubular body 702 that is at least partially made of a cementitious material. In other cases, the conduit 728 is comprised of a metal or plastic object (e.g., steel pipe, PVC pipe, etc.) disposed through the tubular body 702.

[0037] In some variations, the second circumferential wall 724 has a plurality of teeth 732, each tooth 732 protruding from the second circumferential wall 724 in a direction perpendicular to the axis 720 of the tubular body 702. The plurality of teeth 732 may be formed by undulations or undulations in the second circumferential wall 724, for example, as shown in FIGS. 7A-7D . However, other configurations are possible for the plurality of teeth 732. After installation of the example anchor 700, the plurality of teeth 732 can help the shear key 718 resist rotational displacement of the example anchor 700 about the axis 720 of the tubular body 702. The straight wall 722 can also help the shear key 718 resist rotational displacement of the example anchor 700.

[0038] In some embodiments, the example anchor 700 is configured to resist rollover when immersed in the water bottom. For example, the tubular body 702 can be configured to have a length and a maximum diameter, where the length is less than or equal to the maximum diameter. In this configuration, the tubular body 702 can provide a "stubby" body for the example anchor 700. As another example, the tubular body 702 can be truncated. Thus, the diameter of the peripheral wall 714 at the open end 708 of the tubular body 702 can be smaller than the diameter of the peripheral wall 714 at or near the bottom wall 712.

[0039] In some embodiments, the example anchor 700 has stiffening walls to increase the stiffness of the body. For example, the tubular body 702 can extend along an axis 720, and the tubular body can have stiffening walls disposed within a cavity 716 and oriented parallel to the axis 720. The stiffening walls can have first and second wall ends extending therebetween. The first and second wall ends can terminate in a peripheral wall 714. FIG. 9 is a schematic top perspective view of an example anchor 900 having multiple stiffening walls 902. Each stiffening wall 902 passes through the axis 904 of the tubular body 906 to define a common wall intersection 908. The tubular body 906 has a bottom wall (not shown), a peripheral wall 910, and a shear key 912. A pad eye 914 is coupled to a common wall intersection 908 near the open end 916 of the tubular body 906. The shear key 912 has a second peripheral wall 918 that transforms the now closed end of the tubular body 906 into a second open end 920. Four pad eyes 910 are also coupled to the exterior side of the bottom wall, which may form part of the exterior surface of the tubular body 906.

[0040] The anchors described herein may be manufactured by depositing layers of a flowable cementitious material. In an embodiment, a method of manufacturing an anchor includes depositing layers of the flowable cementitious material on top of one another to form at least a portion of a tubular body. The flowable cementitious material is capable of hardening to a solidified cementitious material. The tubular body may further include features such as those described in connection with FIGS. 2A-9. For example, the tubular body may have an open end and a closed end, and the tubular body may have a bottom wall defining the closed end of the tubular body, the bottom wall having first and second surfaces on opposite sides. The tubular body may further include a peripheral wall extending from the first surface of the bottom wall to the open end of the tubular body. The peripheral wall may define an opening at the open end that leads into a cavity of the tubular body. The tubular body may further include a shear key extending from the second surface of the bottom wall. The shear key is configured to penetrate the water bottom and resist lateral displacement of the anchor along the water bottom as it penetrates and penetrates into the water bottom. The method further includes securing a pad eye to the tubular body, the pad eye configured to couple to the mooring line, and in many embodiments, the method further includes allowing the layer of flowable cementitious material to harden into a layer of set cementitious material. In some variations, securing the pad eye to the tubular body includes coupling the pad eye to a reinforcing element of the tubular body and then allowing the layer of flowable cementitious material to harden.

[0041] Depositing the layers of flowable cementitious material may be part of a manufacturing process including 3D casting (which may 3D print stayform walls onto which concrete material is cast), concrete spraying, precasting, casting, slip molding, etc. In some embodiments, depositing the layers of flowable cementitious material includes spraying the layers of flowable cementitious material on top of one another. In some embodiments, depositing the layers of flowable cementitious material includes printing the layers of flowable cementitious material on top of one another.

[0042] In some embodiments, the shear key has a second peripheral wall configured to convert the closed end of the tubular body into a second open end. The second peripheral wall can define a second opening leading into a second cavity in the tubular body, which can be configured as a suction chamber of the anchor. Additionally, the anchor can include a conduit configured to fluidly couple the suction chamber to an exterior of the second anchor. In this case, the conduit can be defined by a conduit wall of the tubular body. Accordingly, in some variations, depositing the layer of flowable cementitious material can include depositing the layer of flowable cementitious material to at least partially form the conduit wall.

[0043] In some aspects of the described subject matter, the anchor can be described in terms of the following embodiments: The anchor can be used in some specific cases to secure a floating structure to the bottom of the body of water. [Embodiment 1] Anchor, a tubular body at least partially made of a cementitious material and having an open end and a closed end, said tubular body comprising: a bottom wall defining the closed end of the tubular body, the bottom wall having first and second surfaces on opposite sides thereof; a peripheral wall extending from the first surface of the bottom wall to the open end of the tubular body, the peripheral wall defining an opening at the open end into a cavity of the tubular body; a shear key extending from the second surface of the bottom wall, the shear key configured to penetrate the water bottom and resist lateral displacement of the anchor along the water bottom when penetrated into the water bottom; An anchor coupled to the tubular body and having a bad eye configured to couple to a mooring line. [Embodiment 2] The tubular body extends along an axis, and the tubular body comprises: The anchor of embodiment 1, further comprising a stiffening wall disposed within the cavity and oriented parallel to the axis, the stiffening wall having a first wall end and a second wall end, the stiffening wall extending between the first wall end and the second wall end, the first and second wall ends terminating at the peripheral wall. [Embodiment 3] the stiffening wall comprises a plurality of stiffening walls, each stiffening wall passing through the axis to define a common wall intersection; The anchor of embodiment 2, wherein the pad eye is coupled to the common wall intersection near the open end of the tubular body. [Embodiment 4] The anchor of any one of embodiments 2 and 3, wherein the pad eye is connected to an edge surface of the peripheral wall near the open end. [Embodiment 5] The anchor of any one of embodiments 2 or 3, wherein the pad eye is coupled to an exterior side surface of the bottom wall. [Embodiment 6] The anchor of embodiment 1, 2 or 3, wherein the pad eye is connected to a central portion of the bottom wall. [Embodiment 7] The anchor according to any one of embodiments 1 or 2-6, wherein the anchor has a ballast material disposed within the cavity. [Embodiment 8] The anchor of any one of embodiments 1 or 2-8, wherein the cavity is configured to define a volume that, when unfilled, enables the anchor to float when placed on a body of water. [Embodiment Item 9] The anchor according to any one of embodiments 1 or 2-7, wherein the peripheral wall is configured to receive a lid at the open end of the tubular body to cover the open end. [Embodiment 10] The anchor of embodiment 9, having the lid. [Embodiment 11] The above lid is a surface configured to face an exterior of the anchor when covering the open end; and 11. The anchor of embodiment 10, having a contoured wall extending from said surface. [Embodiment 12] The anchor of any one of embodiments 1 or 2-11, wherein the shear key is further configured to resist rotational displacement of the anchor about the axis of the tubular body when penetrated into the water bottom. [Embodiment 13] 13. The anchor of embodiment 12, wherein the shear key has a straight wall extending from the second surface of the bottom wall. [Embodiment 14] 14. The anchor of embodiment 12 or 13, wherein the shear key has a plurality of radial walls extending from the second surface of the bottom wall, each radial wall aligned along a different radial direction extending outward from a center of the bottom wall. [Embodiment 15] The anchor of any one of embodiments 1 or 2-14, wherein the shear key has a second peripheral wall configured to convert the closed end of the tubular body into a second open end. [Embodiment 16] 16. The anchor of embodiment 15, wherein the shear key has first and second sets of chordal walls extending from the second surface of the bottom wall, each chordal wall having a chordal end terminating in the second peripheral wall, and the first set of chordal walls being perpendicular to the second set of chordal walls. [Embodiment 17] the second peripheral wall defines an opening into a second cavity of the tubular body, the second cavity configured as a suction chamber of the anchor; 17. The anchor of embodiment 15 or 16, wherein the anchor comprises a conduit configured to fluidly couple the suction chamber to an exterior of the anchor. [Embodiment 18] 18. The anchor of embodiment 17, wherein the conduit is defined by a conduit wall of the tubular body made at least in part from a cement-based material. [Embodiment 19] The anchor according to any one of embodiments 15 or 16-18, wherein the second circumferential wall has a plurality of teeth, each tooth protruding from the second circumferential wall along a direction perpendicular to the axis of the tubular body. [Embodiment 20] 20. The anchor of embodiment 19, wherein each tooth is defined by an undulation of the second peripheral wall. [Embodiment 21] the tubular body is frustum-shaped; The anchor according to any one of embodiments 1 or 2-20, wherein the diameter of the peripheral wall at the open end of the tubular body is smaller than the diameter of the peripheral wall at the bottom wall. [Embodiment 22] The anchor according to any one of embodiments 1 or 2 to 21, wherein the length of the tubular body is equal to or less than the maximum diameter of the tubular body.

[0044] In some aspects of the described subject matter, the method can be described by the following embodiment section: In some particular cases, the method can be used to manufacture anchors, for example anchors for securing floating structures to the bottom of a body of water. [Embodiment 23] 1. A method of manufacturing an anchor, comprising: depositing layers of flowable cementitious material on top of one another to form at least a portion of a tubular body, the flowable cementitious material hardening to a set cementitious material, the tubular body having an open end and a closed end, the tubular body comprising: a bottom wall defining the closed end of the tubular body, the bottom wall having first and second surfaces on opposite sides thereof; a peripheral wall extending from the first surface of the bottom wall to the open end of the tubular body, the peripheral wall defining an opening at the open end into a cavity of the tubular body; a shear key extending from the second surface of the bottom wall, the shear key configured to penetrate the water bottom and resist lateral displacement of the anchor along the water bottom when penetrated into the water bottom; The method includes securing a pad eye to the tubular body, the pad eye configured to couple to a mooring line. [Embodiment 24] 24. The method of embodiment 23, comprising the step of hardening the layer of flowable cementitious material into a layer of set cementitious material. [Embodiment 25] 25. The method of embodiment 24, wherein the step of securing the pad eye to the tubular body includes the step of bonding the pad eye to a reinforcing element of the tubular body before the layer of flowable cementitious material hardens. [Embodiment 26] 26. The method of any one of claims 23 to 25, wherein the step of depositing the layers of flowable cementitious material comprises spraying the layers of flowable cementitious material in an overlapping state. [Embodiment 27] 27. The method of any one of claims 23 or 24-26, wherein the step of depositing the layers of flowable cementitious material comprises printing the layers of flowable cementitious material on top of each other. [Embodiment 28] 28. The method of any one of embodiments 23 or 24-27, comprising placing a reinforcing element in the flowable cementitious material prior to depositing the layer of flowable cementitious material. [Embodiment 29] The tubular body extends along an axis, and the tubular body comprises: 29. The method of any one of embodiments 23 or 24-28, further comprising a stiffening wall disposed within the cavity and oriented parallel to the axis, the stiffening wall having a first wall end and a second wall end, the stiffening wall extending between the first wall end and the second wall end, the first and second wall ends terminating at the peripheral wall. [Embodiment 30] 30. The method of any one of embodiments 23 or 24-29, wherein the cavity is configured to define a volume that, when unfilled, enables the anchor to float when placed on a body of water. [Embodiment 31] The method of any one of embodiments 23 or 24-30, wherein the peripheral wall is configured at the open end of the tubular body to receive a lid over the open end. [Embodiment 32] 32. The method of any one of embodiments 23 or 24-31, wherein the shear key is further configured to resist rotational displacement of the anchor about the axis of the tubular body when inserted into the submerged floor. [Embodiment 33] 33. The method of embodiment 32, wherein the shear key has a straight wall extending from the second surface of the bottom wall. [Embodiment 34] 34. The method of any one of embodiments 23 or 24-33, wherein the shear key has a second peripheral wall configured to transform the closed end of the tubular body into a second open end. [Embodiment 35] the second peripheral wall defines an opening into a second cavity of the tubular body, the second cavity configured as a suction chamber of the anchor; 35. The method of embodiment 34, wherein the anchor has a conduit configured to fluidly couple the suction chamber to an exterior of the anchor. [Embodiment 36] the conduit is defined by a conduit wall of the tubular body; 36. The method of embodiment 35, wherein said step of depositing a layer of flowable cementitious material comprises depositing a layer of flowable cementitious material to at least partially form the conduit wall. [Embodiment 37] The method of any one of embodiments 34 to 36, wherein the second peripheral wall has a plurality of teeth, each tooth protruding from the second peripheral wall along a direction perpendicular to the axis of the tubular body.

[0045] While this specification contains many details, these details should not be construed as limitations on the claimed subject matter, but rather as descriptions of features specific to particular embodiments. Certain features described herein or illustrated in the drawings in the context of separate embodiments are also possible in combination. Conversely, various features described or illustrated in the context of a single embodiment may also be embodied in multiple embodiments separately or in any suitable subcombination.

[0046] Similarly, although acts may be depicted in a particular order in the figures, this should not be understood as a requirement that such acts be performed in the particular order or sequential order depicted, or that all of the depicted acts be performed, to achieve desired results. In certain circumstances, parallel operation or processing may be advantageous. Furthermore, the separation of various system components in the above-described embodiments should not be understood as a requirement that such separation be present in all embodiments, nor should it be understood that the described program components or systems may generally be integrated together into a single product or packaged into multiple products.

[0047] Although a number of illustrative embodiments have been described, it will be understood that various modifications may be made and, accordingly, other embodiments are within the scope of the invention as defined by the following claims.

Claims

1. It is an anchor, It is made of at least part cement-based material and has a tubular body with an open end and a closed end, and the tubular body is, The tubular body has a bottom wall that constitutes the closed end, and the bottom wall has first and second surfaces on the opposite sides of the bottom wall. The bottom wall has a circumferential wall that extends from the first surface to the open end of the tubular body, and the circumferential wall defines an opening at the open end that leads to the cavity of the tubular body. The bottom wall has a shear key extending from the second surface, the shear key is configured to penetrate the seabed and resist lateral displacement of the anchor along the seabed when it is embedded in the seabed, An anchor having a pad eye connected to a portion of the tubular body and configured to be connected to a mooring rope, wherein the portion of the tubular body includes the outer side surface of the bottom wall or the surface of the peripheral wall.

2. The tubular body extends along the axis, and the tubular body is The anchor according to claim 1, comprising a stiffening wall provided within the cavity and directed parallel to the axis, wherein the stiffening wall has a first wall end and a second wall end, the stiffening wall extends between the first wall end and the second wall end, and the first and second wall ends terminate at the circumferential wall.

3. The anchor according to claim 1, wherein the portion of the tubular body includes the central portion of the first surface of the bottom wall.

4. The anchor according to claim 1, wherein the anchor has ballast material provided in the cavity.

5. The anchor according to any one of claims 1 to 4, wherein the cavity is configured to determine a volume that, if not filled, allows the anchor to float when placed on a body of water.

6. The anchor according to any one of claims 1 to 4, wherein the peripheral wall is configured to receive a lid that covers the open end of the tubular body.

7. The anchor according to any one of claims 1 to 4, wherein the shear key has a second peripheral wall configured to convert the closed end of the tubular body into a second open end.

8. The second peripheral wall defines an opening that leads to the second cavity of the tubular body, and the second cavity is configured as the suction chamber of the anchor. The anchor according to claim 7, wherein the anchor has a conduit configured to fluidly couple the suction chamber to the outside of the anchor.

9. The anchor according to any one of claims 1 to 4, wherein the length of the tubular body is less than or equal to the maximum diameter of the tubular body.

10. A method for manufacturing an anchor, The process includes the step of depositing layers of fluid cement-based material in an overlapping manner to form at least a portion of a tubular body, wherein the fluid cement-based material is capable of hardening and solidifying into a cement-based material, and the tubular body has an open end and a closed end, and the tubular body is The tubular body has a bottom wall that constitutes the closed end, and the bottom wall has first and second surfaces on the opposite sides of the bottom wall. The bottom wall has a circumferential wall that extends from the first surface to the open end of the tubular body, and the circumferential wall defines an opening at the open end that leads to the cavity of the tubular body. The bottom wall has a shear key extending from the second surface, the shear key is configured to penetrate the seabed and resist lateral displacement of the anchor along the seabed when it is embedded in the seabed, A method comprising the step of fixing a pad eye to a portion of the tubular body, wherein the pad eye is configured to be coupled to a mooring rope, and the portion of the tubular body includes the outer side surface of the bottom wall or the surface of the circumferential wall.

11. The method according to claim 10, further comprising the step of hardening the layer of fluid cement-based material into a solidified layer of cement-based material.

12. The method according to claim 10 or claim 11, further comprising the step of introducing reinforcing elements into the fluid cement-based material before the step of depositing the fluid cement-based material layer.

13. The tubular body extends along the axis, and the tubular body is The method according to claim 10 or claim 11, wherein a stiffening wall is provided within the cavity and directed parallel to the axis, the stiffening wall having a first wall end and a second wall end, the stiffening wall extending between the first wall end and the second wall end, and the first and second wall ends terminating at the circumferential wall.

14. The method according to claim 10 or 11, wherein the cavity is configured to determine a volume that, if not filled, would allow the anchor to float when placed over a body of water.

15. The method according to claim 10 or claim 11, wherein the peripheral wall is configured to receive a lid that covers the open end of the tubular body at the open end.

16. The second peripheral wall defines an opening that leads to the second cavity of the tubular body, and the second cavity is configured as the suction chamber of the anchor. The method according to claim 10 or 11, wherein the anchor has a conduit configured to fluidly couple the suction chamber to the outside of the anchor.

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