HK40023314B - Harbour plant and method for mooring a floating body in a harbour plant - Google Patents

Description

Harbor equipment and method for mooring a buoy in a harbor equipment

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority from Norwegian patent application No. 20161699, filed on October 27, 2016, the entire contents of which are incorporated herein by reference for all purposes.

Technical Field

The invention relates to a method and a system for mooring a floating body in a harbour installation, the harbour installation comprising a piled base structure provided with two side walls projecting upwards through the sea level and terminating above the sea level, and a transversely arranged bottom structure rigidly connecting the side walls to each other, wherein a top surface of the bottom structure is arranged at a depth allowing the floating body to float between the two side walls, and wherein the floating body (or floating structure) is arranged to be rigidly but releasably supported by at least a portion of the side walls.

Background Art

A major problem for floating offshore structures in waters exposed to extreme sea conditions, such as storm surges, is that storm surges, such as those associated with tropical cyclones, occur primarily in shallow waters near land, where water levels near the coast can temporarily increase by as much as 8 to 9 meters. This imposes significant uplift forces on gravity-based structures (GBSs), which have a large horizontal area of liquid stored at sea level and are located near shore. The additional fixed ballast required to offset this temporary uplift force would necessitate a significant increase in the volume and weight of the GBS to ensure a consistently positive bottom pressure and to provide additional buoyancy during the GBS's floating, submersion, and installation on the seabed. This increase in volume would in turn lead to a further increase in uplift forces, necessitating additional ballast for both seawater ballast and fixed ballast – a negative design effect spiral that would make GBS solutions very expensive.

It is also known that GBS solutions may not be feasible or, at best, would be prohibitively expensive for use in soft, unconsolidated seabed soils such as those found in river deltas. For these reasons, GBS can be equipped with a suction skirt, but the extremely small size and vertical height of such skirt solutions may represent an excessively expensive foundation solution, with floating storage bodies being the only feasible solution to date in areas with such soil conditions.

In order to reduce the problems associated with the dynamics of the floating body during loading operations, it has been proposed to install large rectangular or square steel or concrete structures on the seabed to serve as artificial harbors, wherein continuous steel or concrete walls are intended to form a protection against incident waves. Typical water depths proposed are 8 to 30 meters. This type of large structure is intended to be built away from densely populated areas and at the same time serve as a breakwater for liquefied natural gas (LNG) ships during loading and unloading operations.

The wave problem could be reduced by moving ships onto the leeward side of the harbor structure. However, calculations and basin experiments have shown that if a harbor structure forming a continuous barrier is to achieve a significant shielding effect when waves and swells occur at particularly unfavorable angles during a period of time, then the harbor structure forming a continuous barrier must be built very large. This is due to the well-known effect that waves will diffract around the sides of such a structure and produce a focal point some distance behind the leeward side where the diffracted waves meet. At this focal point, the wave height can actually be higher than the incident wave.

Large harbor structures placed on the seabed are intended to serve as a wave shelter and are therefore very expensive. Various forms of this type of harbor site have been proposed for LNG, constructed from concrete to shield ships from the effects of waves during loading operations. One proposed shape is to build the structure in a horseshoe shape, for example, and have LNG ships load and unload inside the structure. This would significantly reduce dynamic problems, but the harbor site would be more expensive than a rectangular port site.

GB 1369915 describes a harbour station comprising a plurality of units that are floating or submerged and otherwise configured for placement on the seabed. Each unit comprises a base, a load-bearing structure and movable wave-breaking elements that can be moved if required.

US 3,958,426 describes a harbour site comprising a plurality of units arranged on the seabed in a spaced-apart manner so as to form at least one straight mooring position. The units are provided with protection means and wave damping means.

WO 2006/041312, the entire contents of which are incorporated herein by reference, discloses a port facility for storing, loading, and unloading hydrocarbons, such as LNG, at sea. The port comprises three units constructed of steel or concrete and placed on the seabed. These units are arranged in a linear configuration with a side-to-side relationship. The port is designed to dampen waves, with vessels intended to be positioned on the leeward side of the moorings.

WO 2013/002648 discloses a port facility for storing, loading, and unloading hydrocarbon products at sea, comprising a plurality of units arranged relative to one another on the seabed to form the port facility. The units are independently arranged at predetermined distances in a lateral direction and have front surfaces along which vessels are intended to be moored, thereby forming a channel for a portion of the waves, and the units are configured to suppress a portion of the incoming waves while allowing another portion of the waves and the current to pass through the port facility.

US 2005/139595 describes an LNG storage and loading facility comprising a seabed structure disposed on the seabed, the structure having a bottom plate disposed on the seabed and three upwardly extending walls. The seabed structure has openings to allow floating modules to be maneuvered into position within the seabed structure and ballasted to rest on the bottom plate.

FR 2894646 describes a gravity-based structure that rests on the seabed due to its own weight and is provided with a downwardly projecting, open skirt that presses downward into the seabed. The gravity-based structure has a U-shaped form, with vertical walls extending upward from a submerged floor, and is provided with buoyancy chambers that act as weights to provide the required gravity. One embodiment of the gravity-based structure may also be provided with piles extending downward through the vertical walls and into the supporting soil, terminating at the top of the walls above sea level.

However, these port facilities for storage may be large, complex and expensive. These port facilities require a long time to build and are limited in their variations relative to mobility and other applications. Due to the dependence of the deeper skirt, foundations may be problematic during installation, particularly in shallow waters with muddy or soft seabeds. In addition, the density, composition, compaction and topography of the seabed soil may vary greatly from one seabed location to another. For example, the soil in an estuary will typically be based on a soft muddy soil with a gelatinous texture, while other seabed areas may be affected by or overlaid with hard sandstone, limestone or ancient volcanic rocks. This will have a direct impact on the load-bearing capacity of the seabed soil and therefore may find a predictable and reliable foundation solution for seabed structures that should be placed on the seabed.

Therefore, there is a need for a cost-effective, versatile and flexible port equipment system that can be installed in shallow waters and is suitable for installation in areas where the seabed has poor load-bearing capacity. In addition, there is a need for offshore equipment that can be standardized as much as possible for manufacturing and cost reasons and can be easily deployed in offshore or nearshore locations with any type of seabed soil.

There also exists a need for a method for ensuring proper and sufficient piling of such harbour equipment, thereby avoiding relative movement between the equipment and the seabed during the piling operation.

Summary of the Invention

The principle used in accordance with the present invention is to use a piled base structure, wherein the weight of the floatable body moored in and supported by the base structure is transferred directly downwardly into the seabed by piles, which terminate above sea level and are carried and/or fixed by a structure above sea level. In addition, another principle used is to use gravity and/or ballast to safely moor or anchor the floatable body to the docking bay. The floatable body or float can be exposed to buoyancy forces by allowing a water-filled gap at least between the bottom of the floatable body and the corresponding upper surface of the base structure. The floatable body can optionally be moored to the docking bay (or base structure) in conjunction with a mooring force. In this regard, the base structure can be placed on the seabed by at least a portion of its footprint, or the base structure can be positioned at a distance above the seabed soil, that is, without actually contacting the seabed soil, with all loads, weights, and forces being carried and transferred to the seabed by the piles in any case.

The object of the present invention is to provide a foundation and support system and installation method for a base structure that transfers loads, forces and moments from a moored floating structure (or buoy) directly into deeper layers of the seabed soil without causing failure or instability of the support or mooring foundation due to environmental forces or other related forces acting on the base structure.

Another object of the present invention is to provide a multi-purpose shallow water seabed terminal having a moored floatable storage body and a method for establishing a fixing arrangement between the float and the base structure.

A further object of the present invention is to provide a seabed terminal designed to transfer substantial vertical loads caused by the large weight of liquid stored in the moored body (i.e., the moored floatable body) and/or the forces and loads acting on the seabed terminal to the seabed soil without allowing any relative movement between the floating body and the supporting structure and any relative movement between the seabed and the terminal.

Yet another object of the present invention is to provide a shallow water seabed terminal that is flexible to use, inexpensive, and easy to establish in most types of seabed soil conditions.

A further object of the invention is to provide an offshore storage system which, if necessary, can also be located in extremely soft and muddy soils, such as occur in river deltas and seabed areas with unconsolidated soils, where the installation of gravity-based structures is not possible or would be too expensive, and in which the floating body can be removed again upon completion of its mission without undue complexity.

Yet another object of the present invention is that it can be given the structural capacity to resist large buoyancy uplift forces during extreme storm surges without any major volumetric modification to its load bearing structure.

A further object of the present invention is to directly ensure the safe transfer and/or distribution of large vertical loads and forces resulting from the large amount of liquid stored in the buoy and/or from the loads and forces generated by sea conditions and weather, from the buoy to the base structure and from the base structure to the piles and from the piles to the seabed.

Yet another object of the present invention is to provide a seabed terminal comprising a seabed structure and a floatable modular body, the seabed structure and the floatable modular body being particularly designed to adapt to each other and to simplify the docking and mooring of the floatable body in a time-saving and cost-effective manner.

Yet another object of the present invention is to provide a fast, safe and releasable installation and mooring of a floating body with topside equipment.

Yet another object of the present invention is to avoid local failure of one or more piles due to local overload shocks caused by the assembled base structure and floating structure, the acting loads and forces being balanced and distributed also to adjacent piles.

Yet another object of the present invention is to provide a mooring system based on a piling system, wherein the acting loads and forces caused by environmental forces acting on the assembled structure or the loads and forces exerted by the floating structure on the base structure are distributed in a controlled manner through the interfaces between the floating structure and the base structure and between the base structure and the piling system, thereby avoiding excessive stresses and strains in the respective interfaces and avoiding ground failures in the interfaces between the piles and the surrounding seabed soil.

Another object of the present invention is to provide a solution wherein the position of the floating structure relative to the base structure can be vertically aligned and/or the vertical position of the floating structure can be locally adjusted in order to ensure a balanced load and/or force distribution of the acting loads and forces through the system.

Yet another object of the present invention is to provide a load and force transfer system wherein a balanced load and force distribution is established, thereby ensuring that loads and forces are transferred through the base structure into the pile in a manner that avoids excessive local stress and strain overloads.

Another object of the present invention is to provide a seabed terminal or port or harbour installation with shelter for vessels, which advantageously can be more cost effective than using potentially relatively expensive breaking wave structures.

The objects of the present invention are achieved by a seabed terminal and a method for establishing such a seabed terminal as further defined by the independent claims. Embodiments, alternatives and variants of the invention are defined by the dependent claims.

According to an embodiment, a method for mooring a buoy in a harbor facility is provided. The harbor facility may include a piled base structure having two side walls that protrude upward through and terminate above sea level, and a transversely arranged bottom structure rigidly interconnected with the side walls. The two side walls may be opposing side walls facing each other.

In other words, the base structure may be arranged to be supported by the seabed by means of a plurality of piles. For example, the piles may terminate at the top surface of the sidewalls above sea level. In the context of various embodiments, a buoy may refer to a floating structure or a floating member or a floating module.

The top surface of the base structure is arranged at a depth that allows the float to float between the two side walls. Furthermore, the float is arranged to be rigidly but releasably supported by at least a portion of the side walls. The float floats into position between the side walls and is rigidly secured to the vertical side walls of the base structure while being substantially fully exposed to buoyancy forces, thereby preventing relative vertical movement between the float and the base structure by allowing a water-filled gap to exist between at least the bottom of the float and the corresponding upper surface of the base structure.

The float can optionally be rigidly fixed to the base structure by arranging a plurality of tensioning devices between the float and the upper part (or upper end or top part or top end) of the side wall, one end of the tensioning device being rigidly fixed to a support portion on the float and the opposite end being rigidly fixed to the upper part of the side wall.

For example, tension rods apply additive forces that combine with gravity and ballast to increase holding capacity to accommodate changes in vertical loads.

According to the present invention, it is possible to allow the surface on the floating body to rest on the surface on the upper end surface (top surface) of the side wall in close association with the upper ends of the piles, which support the base structure on the seabed and extend vertically downward through the side wall and into the seabed.

When the floating body is allowed to float between the two side walls, the floating body can be provided with support portions on portions that protrude laterally from the sides of the floating body, and the support portions of the floating body can be positioned above (or on) the top (or top surface or top portion) of the side walls of the base structure. The top surfaces of the side walls can be provided with correspondingly arranged complementary support portions that are configured to bear at least a portion of the weight of the floating body.

The support on the sidewall can preferably be formed by the top end of the piles that serve as the foundation for the base structure, thereby allowing the weight from the supported floating body to be transferred directly to the seabed through the piles. The top end of the pile can refer to the end region (or end portion) of the pile, which is the side of the end region where the pile can terminate, for example, at the top surface of the sidewall. It should be understood and appreciated that the pile does not necessarily have to terminate at the top surface of the sidewall. In other words, the pile can terminate anywhere along the pile sleeve.

Part of the weight of the floating body can preferably be compensated by means of buoyancy, and the ballast water can be increased in the event of an increase in the sea level, and/or in this case the increase in the lifting force is taken up by the tensioning device.

Damping means may be arranged on the top surface of the side walls, the damping means being configured to act as shock absorbers during engagement of the floating body on the base structure, thereby ensuring a controlled transfer of loads and forces to the base structure, and also ensuring that the loads and forces are distributed in a manner that prevents overloading of a portion of the base structure and/or adjacent piles below.

According to another embodiment of the invention, jacks may be arranged between each support on the top of the side wall and the corresponding support on the floating body, thereby allowing the floating body to be lifted so as to achieve an optimal weight and/or buoyancy balance between the two structures and between the mated structure on the one hand and the piling interface to the seabed on the other hand.

The distal end of the tensioning device can be rigidly fixed to a support on the floating body and the opposite end can be rigidly fixed to a support at the upper end of the side wall. More specifically, the tension in the tensioning device can be adjusted to ensure sufficient support and fixing force, with one end of each tensioning device fixed to a support on the top surface of the side wall and the other end fixed to the floating body.

The invention also relates to a harbour installation for the mooring of a floating body as described above, wherein the vertical side walls are configured to bear the weight of the floating body by means of rigid but releasable fixing means while still allowing the floating body to be substantially exposed to buoyancy forces due to the presence of a water-filled gap between at least the bottom of the floating body and the corresponding upper surface of the base structure, and wherein relative vertical movement between the floating body and the base structure is prevented by arranging a plurality of tensioning devices between the floating body and the top of the side walls.

According to one embodiment, the support portions on the floating body can be arranged on vertical surfaces protruding laterally from the sides of the floating body, and these support portions on the floating body can be arranged/positioned above the top of the side walls of the base structure, and the top surfaces of the side walls are provided with correspondingly arranged complementary support portions, which are configured to bear at least part of the weight of the floating body.

The supports on the side walls may be formed by the top ends of piles used as foundations for the base structure, allowing the weight from the supported buoyancy to be transferred directly through the piles into the seabed.

Jacks may be arranged between the supports on the top of the side walls and below the bottoms of the supports protruding laterally from the floating body to adjust the tension in the tensioning device.

Furthermore, the tensioning device may be provided with means for adjusting the tension in order to ensure sufficient supporting and fixing force.

The supports on the top surface of the sidewalls correspond to or are closely associated with the upper ends of the piles which support the base structure and which extend through the sidewalls and into the seabed.

The wall structure may form an integral part of the base structure thereby forming a seabed substructure unit and may be provided with means for ballasting.At least a portion of the wall structure extends above the water surface.

According to the present invention, a shallow-water base structure is provided, for example for storing and loading or unloading hydrocarbons such as LNG, oil or natural gas, the base structure comprising a floatable seabed substructure intended to be supported by the seabed, the seabed substructure preferably comprising a base structure provided with an upwardly extending wall structure arranged along at least a portion of its perimeter, the base structure preferably also being provided with openings in the wall structure for allowing a floatable body to be berthed, moored and supported by the seabed substructure. The base structure is provided with support portions configured to receive corresponding support portions on a floating body and preferably also separating support portions for connection to the ends of pre-installed vertical piles, so as to at least temporarily support the base structure during a piling operation for permanently piling the base structure into the seabed.

The support may be arranged on top of the side wall above sea level.

The supports may be positioned at various locations along the exterior of the sidewalls. In other embodiments, the supports may be arranged at any location on the base structure such that the supports are configured to receive corresponding supports on the buoy and are preferably arranged to connect to the ends of pre-installed vertical piles to at least temporarily support the base structure during piling operations to permanently pile the base structure to the seabed.

It will be appreciated that the support on the floating body may be arranged at a position that allows it to be arranged/positioned above the support of the base structure.

According to an embodiment, the wall structure may form an integral part of the base structure and the support portion forms an integral part of the wall structure.

Alternatively, the supports may be located on a side wall or on a bottom surface of the base structure below sea level.Where the supports are located on a bottom surface of the base structure below sea level, the piles may form a permanent part of the piling system.

The base structure is piled to the seabed using a plurality of permanent piles driven into the seabed, the tops of the piles being rigidly fixed to the base structure along the height of the side walls.

The seabed substructure includes a base structure provided with buoyancy means and an upwardly extending wall structure also provided with buoyancy means. The wall structure is arranged along at least a portion of the perimeter of the base structure and includes at least one opening therein for introducing a floatable storage module. The floatable module is removably arranged within the wall structure on top of the base structure, thereby forming an offshore unit supported by the seabed at least by means of piling.

According to a preferred embodiment of the present invention, the wall structure of the base, which forms an integral part of the base structure, forms the seawater substructure unit. Furthermore, the cantilevers, beams, or plates arranged at the top of the side walls form an integral part of the wall structure and are designed and dimensioned to withstand all temporary load forces and bending moments occurring during the piling process. For this purpose, the cantilevers, beams, or plates may be provided with bearings to cooperate with the temporarily installed piles.

It will be appreciated that the buoyancy base may be provided with ballast tanks and a pumping system which uses water to adjust for weight and buoyancy as well as vertical forces and load exposure acting on the system during operation.

The wall structure of the seabed substructure ends above the sea level. As shown in the accompanying drawings, some of the advantages of having part of the seabed substructure above the water surface are:

a) The horizontal plane facilitates and reduces uncertainty regarding stability during installation of the seabed substructure.

b) Part of the seabed structure will facilitate and simplify the floating in and installation of the storage modules.

c) The pile driving machine can be placed on the base structure above the water level, which reduces cost and time, thereby not being affected by the sea conditions during pile driving.

d) Seabed substructures located above the water level will represent additional protection against ship collisions.

e) Some equipment such as cargo loading arms may in some cases be mounted to the seabed substructure and therefore located at a distance from the buoy.

By providing the quay side with outwardly projecting beams or plates, vessels can be moored at a distance from the vertical wall, thereby enhancing the maneuvering and mooring of vessels along the quay side.

Furthermore, this feature of the present invention is also very useful when installed in shallow cyclones and areas exposed to storm surges, where the water level may be as much as 8 to 9 meters above normal sea level in extreme 100-year scenarios. In such cases, the tension rods arranged between the base structure and the buoy can absorb a significant portion of the uplift forces, if not all of them, while the remainder of these extreme temporary uplift forces can be offset by the effective water ballast of the storage modules.

The seabed unit of the seabed terminal can be designed to carry very large vertical loads from the large volumes of liquid stored within the storage modules, typically up to but not limited to 150,000 tons of deadweight corresponding to the capacity of a large oil tanker, to the seabed without causing any movement of the seabed terminal. Some of this capacity can be achieved by increasing the height of the storage volume while maintaining a horizontal footprint of the seabed terminal.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference numerals generally refer to like parts throughout the different views. The drawings are not necessarily drawn to scale, with emphasis generally being placed upon illustrating the principles of the invention. The detailed description will be better understood in conjunction with the accompanying drawings, wherein the drawings and description relate only to preferred embodiments, which are as follows:

Figure 1 schematically shows a perspective view illustrating the driving of an intermediate pile set to support the base structure during installation and permanent piling operations.

FIG. 2 shows schematically and in perspective the base structure in a maneuvering phase in which it is maneuvered on an intermediate pile.

FIG3 schematically and in perspective shows a base structure installed and supported by an intermediate pile group.

FIG4 shows schematically and in perspective the maneuvering phase in which the work barge is moored along one side of the base structure and has piles attached.

FIG5 shows schematically and in perspective a view of the base structure during the driving phase of the permanent piles.

FIG6 schematically illustrates the demobilization phase, during which the driving of the permanent piles is completed.

FIG7 shows schematically and in perspective the base structure which is supported by the seabed by means of piles in its permanent piled position.

FIG8 shows schematically and in perspective the stage in which the float is floating in and supported by the base structure.

FIG9 schematically shows an end view of a base structure and a floating body docked in and supported by the base structure.

Figure 10 shows schematically and in perspective the base structure and the floating structure shown in Figure 9, also indicating the use of tension rods for securing the floating body to the base structure.

FIG. 11 schematically illustrates, on an enlarged scale, an exemplary initial stage for using guide pins for ensuring the correct positioning of the float in the dock.

FIG. 12 shows schematically and on an enlarged scale an exemplary guide pin in a final position with the float in a locked position supported by the dock.

FIG13 schematically shows a side view of a portion of the top surface of the side wall and a corresponding complementary portion of the bottom of the buoy on an enlarged scale.

FIG14 shows schematically and in perspective a view of another embodiment of a base structure according to the invention, wherein the base structure is opened so as to float the float at two opposite ends.

FIG15 shows schematically and in perspective a view of a further embodiment of a base structure according to the invention, wherein the base structure is provided with only one opening for floating the float.

Figure 16 shows schematically a side view of an alternative way of establishing a fixing arrangement between the float and the top of the base structure.

Fig. 17 schematically shows a side view of the fixing device disclosed in Fig. 16 showing details of the positioning of the float relative to the pile and relative to the top surface of the base structure.

18A shows a cross-sectional side view of a floating module and base structure having an upper frustoconical portion, according to various embodiments.

18B shows a perspective view of the floating module of FIG. 18A with a rounded top, according to an embodiment.

18C illustrates a perspective view of the floating module of FIG. 18A having a square top or a rectangular top, according to an embodiment.

19A shows a top view of a base structure having a U-shape, according to an embodiment.

19B shows a top view of a base structure having a partial hexagonal shape, according to an embodiment.

DETAILED DESCRIPTION

The following description of exemplary embodiments refers to the accompanying drawings. Identical reference numbers in different figures represent identical or similar elements. The following detailed description does not limit the present invention. Rather, the scope of the present invention is defined by the appended claims. For simplicity, the following embodiments are discussed with respect to a method for installing a base structure on a seabed, typically and preferably, but not necessarily, on a sloping seabed and/or a seabed with low load-bearing capacity.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosed subject matter. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment.

The key area for the present invention is to provide for the rapid and safe installation of storage modules with top-side equipment, wherein the base structure is stably and rigidly supported during the driving operation of the permanent piles. By forming a pre-installed base foundation—which is stabilized at least by means of piles and pre-leveled to the seabed—the storage modules can then be installed in a few hours.

Furthermore, the present invention offers the possibility of establishing seabed terminations in diverse soil conditions. The density, composition, compaction, and topography of seabed soil can vary significantly from one seabed location to another. This has a direct impact on the load-bearing capacity of the seabed soil, making it possible to develop predictable and reliable foundation solutions for seabed structures supported by the seabed. According to one embodiment, the base foundation can be piled to the seabed in the form of a semi-submersible buoy. In this case, the base substructure can be ballasted as a semi-submersible structure and piled to the seabed via the base structure and, potentially, but not necessarily, the seabed substructure's walls. In these situations, efficient transmission of vertical structural forces is crucial. Advantageously, the main structural beams of the base structure and the storage modules have mirror-image joints. This means that vertical forces from the bulkheads of the storage modules are preferably transmitted directly into the main structural beams of the base structure, and then into the pile structure and, ultimately, to the seabed. Calculations indicate that the piled seabed substructure must withstand and support weights of 100,000 to 120,000 tons.

FIG1 schematically illustrates the first stage of the installation process, wherein two spaced-apart rows of aligned piles 14 are arranged, with the last pile in row 14′ being forced into the seabed 30 by means of a piling barge 15 in conjunction with a crane 16 and a pile driving tool 17 suspended from the crane 16. During this stage, the flat-top barge 15 can be moored by means of conventional seabed anchors (not shown) and mooring lines 18 (two of which are shown). As indicated in the figure, the piles 14 terminate at a predetermined height above sea level 29.

FIG2 schematically illustrates a base structure 10 being towed into position between two aligned rows of piles 14 by a towing vessel 19 and a pair of towing ropes 20. The base structure 10 comprises two vertically arranged side walls 22 rigidly fixed to a bottom structure arranged in the middle, thereby forming a dock structure having a U-shape configured for mooring or docking with a floating body 11. At the top of the vertically extending side walls 22, each side wall 22 is provided with an outwardly projecting cantilever 21, 21′, which extends outwardly on each side of the base structure 10. The cantilever 21, 21′ extends completely transversely from the top of the base structure 10 along the two parallel side walls 22, and each cantilever 21, 21′ is configured to rest on top of a corresponding row of piles 14. For this purpose, the cantilevers 21, 21' are provided with bearing portions 24 (not shown in Figure 2) which are sized and configured to temporarily transfer the weight of the base structure 10 and also to carry temporarily occurring loads, forces and bending moments introduced at least during the installation phase of the base structure 10 until the base structure is safely piled to the seabed 30.

The base structure 10 is provided with a ballasting system (not shown) and is preferably made of steel, but other materials, such as concrete, may also be used. It should be understood that the base structure 10 according to the present invention may also be provided with auxiliary equipment and systems, such as loading systems, cranes, winches, etc., permanently or temporarily arranged on top of the base structure 10. When the float or module 11 arrives on site, it is maneuvered in a floating state between two upwardly extending side walls 22. During this mating operation, the float 11 is maneuvered through an opening 23 located at one end of the base structure 10 and between two parallel, upwardly extending side walls 22. The float 11 is guided so that the supports on the float 11 are in vertical alignment with corresponding supports arranged on the top surfaces of the side walls 22. These supports on the top surfaces of the two vertical walls 22 correspond to the top ends of the piles 25 and terminate substantially at the top surfaces of the vertical walls 22. The floating module is then ballasted so that it is stably placed on the upper end of the vertical wall 22 of the base structure 10. In locations where seawater level variations are significant (or in challenging locations), compensation may need to be performed (e.g., by using ballast water, or active ballast). However, in locations where seawater level variations are not significant, compensation, such as by ballast water, may not be required, and the floating module can still be stably placed on the upper end of the vertical wall 22 of the base structure 10. In any case, it should be understood that there should be a gap between the upper surface of the interconnected structure (the base structure) and the bottom surface of the floating body 11. In other words, the upper surface of the interconnected structure and the bottom surface of the floating body 11 are not in direct contact with each other.

FIG3 schematically and in perspective illustrates an embodiment of a base structure 10, which is installed atop and supported by a set of intermediate piles 14. As shown, the temporary piles 14 are aligned with supports 24 projecting laterally from the outer, upper portion of the side walls 22. The base structure 10 comprises two vertically arranged walls 22, interconnected at their lower ends by three horizontally arranged box beams 26 rigidly secured to the side walls 22. Furthermore, as indicated, the base structure 10 is intended to be driven into the seabed 30 using two rows of piles 14. For this purpose, the vertical walls 22 are provided with two rows of casings 27, serving as guides, enabling the piling operation to be performed above sea level 29 through the casings 27 in the vertical walls 22 and into the seabed soil. According to the installation stage shown in FIG3 , the permanent piling process has not yet begun. As further indicated, the box beams 26 may also be provided with sleeves 27 if necessary in order to obtain suitable fixing means of the base structure to the seabed 30 .

FIG4 schematically and in perspective shows the mobilization phase of the pile driving operation, wherein a work barge 15′ is moored alongside the outside of the vertical wall structure 22. A pile 31 to be driven is stored on the deck of the flat-top barge 15′. A hydraulic hammer 32 is also shown. At one end of the base structure, a temporary installation platform 33 is arranged, spanning the two vertical side walls 22, to store another pile 31′ to be driven.

FIG5 schematically and in perspective shows a view of the base structure during the mobilization phase of a pile driving operation for a permanent pile 25 at a gantry platform 34. Each end of the gantry platform 34 travels on tracks (not shown) arranged along each of the side walls 22, thereby enabling the gantry platform to travel along the length of the base structure 10. A crawler crane 35 is arranged on the gantry platform 34. The crawler crane 35 is configured to move back and forth on the gantry platform 34 to collect piles 25 from the pile piles 31, 31' and install the piles 25 through the casing 27 with the aid of a hydraulic hammer 32. As indicated, the hydraulic hammer 32 and the permanent pile 25 are suspended from the hook of the crawler crane 35, and the pile 25 is in the process of being driven through the corresponding casing 27 through the side wall 22.

Additionally, a rail welding station (not shown) travelling on a pair of rails (not shown) located on each of the top sides of the side walls 22 may also be used for welding work involving the securing of the completed pile formation.

The base structure 10 may also be provided with an anti-collision system (not shown) and a mooring and winch system (not shown) for mooring a vessel along at least one side of the base structure 10 .

Figure 6 schematically illustrates the demobilisation phase in which the driving of the permanent piles 25 is completed but before the demobilisation of the gantry platform 34 and crawler crane 35, flat top barge 15' and additional storage platform 33.

FIG7 schematically and in perspective illustrates base structure 10, supported by seabed 30 in its permanent piled position by piles 25. The piles 25 terminate at the top of the upper surface of sidewall 22. As indicated, upwardly projecting ribs or fins 12 are arranged on each side of each pile, serving as supports for supporting buoyant body 11 on base structure 10. Furthermore, a plurality of dampers 37 may be arranged in the spaces on the top surface of the upper wall. The fins or load transfer plates 12 are configured to bear the loads and forces from buoyant body 11 and transfer them downwardly into the piles 25 immediately below and possibly into adjacent piles 25. To this end, the sidewall structure is configured and constructed so that forces are transferred from sidewall 22 and into the piles in a controlled and predictable manner. Loads and forces may be transferred directly into the top end of the pile by a direct vertical transfer arrangement and/or directly into the pile wall along substantially the entire length of the interface between the sidewall 22 and corresponding portions of the pile 25 .

8 schematically and in perspective shows the stage in which the floating body 11 is maneuvered in a floating state between the vertical side walls 22 of the base structure 10 to a position in which the supports (not shown) on the bottom surface of the floating body are vertically aligned with the corresponding supports on the upper surfaces of the side walls 22, so that the floating body 11 descends downward until it rests on and is supported by the vertical walls 22. It should be understood that the floating body 11 is not limited to the shape or configuration shown, but may be modified without departing from the inventive concept.

For example, the buoy 11 may have a T-shaped cross-sectional side view, and a square or rectangular top view (as viewed in FIG8 ). Another example may include a buoy 1800 having an upper frustoconical portion 1802 when viewed from the cross-sectional side view, as shown in FIG18A . The upper frustoconical portion 1802 may be supported by the top edge of a base structure 1804 (which may be described in a similar context to base structure 10 ). This exemplary buoy 1800 may have a circular top view 1808 (as viewed in FIG18B ), or a square or rectangular top view 1810 (as viewed in FIG18C ). The buoy 1800 may include a lower portion 1806 configured to be disposed between two opposing sidewalls of the base structure 1804. The lower portion 1806 may be cylindrical. When viewed from the top, the lower portion 1806 may have, for example, a square or rectangular cross-sectional shape. It should be understood that the lower portion 1806 may have different cross-sectional shapes when viewed from the top.

In order to allow the floating body 11 to be supported in a suitable and sufficient manner, the floating body 11 can be provided with a portion protruding laterally from the lower portion of the floating body 11, said outwardly protruding portion having a lower surface provided with a support portion (not shown) that is intentionally vertically aligned with and in supporting contact with a corresponding support portion on the upper surface of the side wall 22. The embodiment of such supporting contact will be described in more detail below.

FIG9 schematically illustrates an end view of the base structure 10 and the buoy 11 docked in and supported by the vertical sidewalls 22 of the base structure 10. As indicated, the buoy 11 is supported only by the base structure 10 along the upper surface of the vertical sidewalls 22, leaving a gap 38 between the buoy 11 and the base structure 10 at the bottom and along the inner surface of the vertical sidewalls 22. Furthermore, according to the embodiment disclosed in FIG9 , the bottom surface of the base structure 10 is positioned above the seabed 30. However, it should be understood that the base structure can rest partially or completely on the seabed 30, if desired.

FIG10 schematically and in perspective shows the base structure 10 and the buoy 11 shown in FIG9 , and also indicates the use of tension rods 39 for securing and/or attaching the buoy 11 to the base structure 10. The purpose of the tension rods 39 is to attach the buoy 11 to the base structure 10 in a sufficient and safe bearing contact. Furthermore, as indicated in the figure, the buoy 11 and the base structure 10 may be provided with guides 40, preferably arranged at least at two diagonally opposite corners, in order to ensure proper alignment of the buoy 11 during engagement with the base structure 10. Details of the guides will be described in more detail below.

Figures 11 and 12 schematically illustrate, on an enlarged scale, exemplary initial and final stages of the use of the guide device 40. The guide device 40 comprises vertical pins 41 movably disposed within vertical sleeves 42, which are rigidly secured to the lower end of the floating body 11 by means of structural frame elements 43. Corresponding seats 44 are provided on the top surface of the sidewalls 22, configured and dimensioned to receive the lower ends of the vertically movable pins 41. The guide device 40 is used to ensure the correct position of the floating body 11 relative to the base structure 10. When the floating structure 11 is in the correct position floating above the upper surface of the sidewalls 22, and when the movable pins 41 or locating pins are aligned with their seats 44, the pins 41 or locating pins are lowered into the seats 44. With all pins 41 seated relative to their seats 44 on the upper surface of the sidewalls 22, the floating body is in the correct position and can be ballasted until bearing contact is established between the two. Final, precise maneuvering of the buoy 11 may be performed by a towing vessel and/or winch system (not shown).

FIG13 schematically illustrates, on an enlarged scale, a side view of a portion of the top surface of sidewall 22 and a corresponding complementary portion of the bottom of buoy 11. As indicated, a plurality of tension rods 39 are arranged along substantially the entire length of the side surface of float 11 and the upper end of the outer side of sidewall 22. It should be understood that other embodiments may include tension rods 39 (not shown in the figures) arranged differently while still providing for securing buoy 11 and sidewall 22 to one another. For example, one end of each tension rod 39 may be positioned anywhere along the length of the side surface of buoy 11 (or the top surface of buoy 11), and the opposite end of the tension rod 39 may be positioned anywhere along the outer side of the sidewall. However, distributing the tension rods 39 along substantially the entire length may provide a more rigid fixation. The number of tension rods 39 used may also vary.

At the upper end, the tensioning rod 39 is rigidly fixed to the buoy 11 by means of brackets 45 rigidly fixed to the side walls of the buoy 11. Correspondingly, at the lower end, the tensioning rod 39 is fixed to the outer surface of the side wall by corresponding brackets 45' rigidly fixed to said wall. At both ends, the tensioning rod 39 is provided with a socket 46, such as a standard open splice socket terminal, and a rod or wire 47 arranged in the middle, rigidly fixed to the socket 46.

The tensioning device may be in the form of a connecting device or connecting means.

In the context of various embodiments, other forms of connection means or connection devices may include tension rods 39, bolt connections, or welded connections, or clamped connections or any combination thereof.

As appropriate, a sleeve nut 48 may be incorporated into each tensioning rod 39 to allow adjustment of the length of each individual tensioning rod 39 used, to ensure approximately equal tension in the tensioning rods, and/or to control tension when de-ballasting or ballasting the float 11.

Figure 13 also discloses supports 12 arranged along the upper surface of the side wall 22. The supports 12 are in the form of upwardly extending fins or ribs and are arranged along both sides of the side wall 22 and are positioned between each upper end of a pile 25 (not shown in the drawings).

FIG14 schematically and in perspective shows another embodiment of a base structure 10 according to the present invention, in which the base structure 10 is opened to allow the float 11 to float at two opposing ends. As shown, the base structure 10 includes two parallel wall sections 22 arranged in a spaced relationship and interconnected by four transversely extending beams 26, thereby securing the lower ends of the walls 22 together and leaving an open space between them at the bottom surface of the base structure 10. According to the illustrated embodiment, only the vertical wall 22 extending upwardly above sea level during installation is provided with a pile sleeve for receiving a pile, thereby enabling dry piling above sea level 29. To transfer forces arising from the bottom section to the vertically extending side walls 22, the beams 26 may be provided at each end with a larger vertical cross-sectional area that increases toward the beam end and toward the corresponding inner side panels of the vertically extending side walls 22. At their upper ends facing outwards away from the side walls 22 , the side walls are provided with supports 24 to sit on pre-installed temporary piles (not shown). In principle, permanent piling is preferably performed only through the vertical walls 22 .

FIG15 schematically and in perspective shows a view of a further embodiment of a base structure 10 according to the invention, wherein the base structure 10 is provided with only one opening for floating a float 11 (not shown in FIG15 ). The disclosed embodiment is similar to the embodiment disclosed in FIG14 , except that the base structure is provided with only one opening for floating the float from only one side.

In Figure 15, base structure 10 has three adjacent side walls, and when viewed from the top, the three adjacent side walls form a roughly rectangular shape. It should be understood that when viewed from the top, adjacent side walls can form other different shapes. For example, in Figure 19A, when viewed from the top, the side walls of base structure 1900 (which can be described in a context similar to base structure 10) can form a U-shaped shape. In another example 1902 observed in Figure 19B, the shape formed can be a partial hexagon. It should be understood and appreciated that no matter how the shape formed by the side walls, there are openings or gaps to allow the floating structure to be moored between two opposing side walls within the base structure. A base structure having a single opening (i.e., having at least three adjacent side walls) may be beneficial to breaking waves. The side walls may not need to be solid structures. For example, the side walls may include holes or orifices or sleeves located above the waterline.

FIG16 schematically illustrates an end view of an alternative manner of establishing a securing arrangement between the float 11 and the top of the base structure 10 at the top surface of the vertically extending wall 22. As shown, the float 11 is provided with laterally projecting portions positioned above the side walls 22. The side walls 22 are provided with laterally extending cantilever portions 24 (not shown in FIG16 ) that serve as supports for the base structure during at least the installation phase, thereby allowing the base structure 10 to be placed on temporarily installed piles prior to completing the permanent piling operation for the base structure 10. Furthermore, the float 11 is provided with cantilever portions 50 that extend laterally from the main body of the float 11 above sea level 29 and are configured to be placed on and supported by the top surface of the vertical wall 22 located on each side of the base structure 10. To ensure controlled transfer of loads and forces and to securely and safely affix float 11 to the base structure, brackets 51 are secured to engaging surfaces on cantilevered portion 50 on float 11, and corresponding complementary brackets 52 are secured to bearing surfaces at the top of wall 22. The two sets of brackets 51, 52 are bolted, fixed, or welded together. It should be understood that cantilevered portion 50 can be a portion extending along the entire length of the side of the float, or can be positioned as separate cantilevered units in spaced-apart relation along each side of float 11. As shown, there is a certain spacing between the inner surface of side wall 22 of base structure 10 and the side wall of float 11.

FIG17 schematically shows a side view of the fixing device disclosed in FIG16 , showing details of the position of the float relative to the piles and relative to the top surface of the base structure. As shown, there is also a space between the upper surface of the beam 26 and the lower bottom surface of the float, allowing the buoyancy of the float to be changed by pumping ballast into or out of the float 11, which is still fixed to the base structure by means of bracket connections 51, 52.

As indicated in Figure 17, piles 25 driven from above sea level 29 terminate below sea level 29, allowing for a simple and efficient piling operation and also reducing weight and cost. The pile casings may be closed at the top by a plate structure, and bracket connectors 51, 52 may be located between two adjacent pile casings or on top of the pile casings.

According to the disclosed embodiment, one row of piles or two rows of piles are disclosed. However, it should be understood that the number of rows can be more than two.

In the disclosed embodiment, vertically oriented piles are shown. However, it will be appreciated that one or more of the piles may be angled downwardly and laterally from the base structure.

According to the embodiment shown, the piles terminate at the upper end surface of the side wall 22. However, it will be appreciated that the piles could terminate at a lower level within the side wall 22 than the upper surface, thereby saving on the length of pile used.

Claims (18)

1. A method for mooring a floating body (11) in a port facility, The port equipment includes: A piled foundation structure (10), the piled foundation structure (10) having two sidewalls (22) that project upward through the sea level (29) and terminate above the sea level (29); and A transversely arranged beam (26) is rigidly connected to the sidewalls (22), wherein the top surface of the beam (26) is arranged at a depth allowing the float (11) to float between the two sidewalls (22), and wherein the float (11) is shaped with lateral protrusions and arranged to be rigidly but releasably supported by at least a portion of the sidewalls (22). The method includes positioning the float (11) between the sidewalls (22), wherein at least a portion of the lateral protrusion is positioned above the sidewalls (22); and The float (11) is rigidly fixed to the sidewall (22) of the base structure (10) while allowing the float (11) to be substantially fully exposed to buoyancy, at least at the corresponding portions of the bottom of the float (11) and the top surface of the beam (26), thereby preventing relative vertical movement between the float (11) and the base structure (10). Rigidly fixing the float (11) to the sidewall (22) of the base structure (10) includes fixing a bracket (51) and a complementary bracket (52) to each other, the bracket (51) being fixed to the engagement surface of the lateral protrusion, and the complementary bracket (52) being fixed to a support surface at the top of the sidewall (22), wherein the engagement surface and the support surface are arranged to face each other, and the support surface is positioned on the top of a pile of the piling base structure (10) or between adjacent piles of the piling base structure (10). 2. The method according to claim 1, wherein rigidly fixing the float (11) to the sidewall (22) of the base structure (10) further comprises arranging a plurality of tensioning devices (39) between the float (11) and the upper portion of the sidewall (22), the tensioning devices (39) being arranged to rigidly fix one end to a support on the sidewall of the lateral protrusion of the float (11), and the opposite end being arranged to rigidly fix to the upper portion of the sidewall (22). 3. The method according to claim 2, wherein a portion of the weight of the float (11) is borne by buoyancy, and ballast water is added when the seawater level increases, and/or in this case, the increase in lifting force is borne by the tensioning device (39). 4. The method according to any one of claims 1 to 3, further comprising allowing a surface on the float (11) to be placed on the upper end surface of the sidewall (22) in a manner closely associated with the upper end of the pile (25), the pile (25) supporting the base structure (10) and extending through the sidewall (22) and into the seabed (30). 5. The method according to any one of claims 1 to 3, further comprising providing a support for the float (11) on the bottom surface of the lateral projection of the float (11) and above the top of the sidewall (22) of the base structure (10), wherein the top surface of the sidewall (22) is provided with a correspondingly arranged complementary support, the complementary support being configured to bear at least a portion of the weight of the float (11). 6. The method according to claim 5, wherein the support portion on the top surface of the sidewall (22) is formed by the top end of a pile (25) serving as a foundation for the base structure (10), thereby allowing the weight from the supported float (11) to be transferred directly to the seabed (30) through the pile (25). 7. The method according to claim 5, wherein a jack is arranged between the top surface of the sidewall (22) and at least a portion of the lateral protrusion positioned above the sidewall (22) to allow lifting of the float (11), the jack serving as an impact absorber. 8. The method according to any one of claims 1 to 3, wherein a damping device is arranged on the top surface of the sidewall (22), the damping device being configured to function as an impact absorber during the engagement of the float (11) with the base structure (10). 9. The method according to any one of claims 1 to 3, wherein the support (51) and the complementary support (52) are welded to each other. 10. A port facility for mooring a floating body (11), the port facility comprising a piled base structure (10) and a floating body (11), the base structure (10) having two sidewalls (22) projecting upward through the sea level (29), the two sidewalls (22) being interconnected by transversely arranged beams (26). The base structure (10) is arranged to be supported by the seabed by a plurality of piles (25), which terminate above the sea level (29) at the top surface of the sidewall (22) or below the sea level (29) within the sidewall (22). The float (11) is formed with lateral protrusions and is arranged to be rigidly but releasably supported by at least a portion of the top surface of the sidewall (22). The top surface of the beam (26) is arranged at a depth that allows the float (11) to float between the two sidewalls (22), wherein at least a portion of the lateral protrusion is positioned above the sidewalls (22). The sidewall (22) is configured to support the weight of the float (11) by a rigid but releasable fixing device, while still allowing a water-filled gap at least between the bottom of the float (11) and the corresponding portion of the top surface of the beam (26), wherein the fixing device includes a bracket (51) and a complementary bracket (52) configured to be fixed to each other, the bracket (51) being fixed to the engagement surface of the lateral protrusion, and the complementary bracket (52) being fixed to a support surface at the top of the sidewall (22), wherein the engagement surface and the support surface are arranged to face each other, and the support surface is positioned on the top of the piles of the piling base structure (10) or between adjacent piles of the piling base structure (10). 11. The port equipment according to claim 10, wherein the support portion on the float (11) is arranged on the bottom surface of the lateral protrusion of the float (11) and above the top of the side wall (22) of the base structure (10), the top surface of the side wall (22) being provided with a correspondingly arranged complementary support portion, the complementary support portion being configured to bear at least a portion of the weight of the float (11). 12. The port equipment according to claim 10, wherein a plurality of tensioning devices (39) are arranged between the float (11) and the upper portion of the sidewall (22) to prevent relative vertical movement between the float (11) and the base structure (10). 13. The port equipment according to claim 12, wherein one end of the tensioning device (39) is rigidly fixed to a support on the float (11) and the opposite end is rigidly fixed to a support at the upper portion of the sidewall (22). 14. The port equipment according to claim 13, wherein a jack is arranged between the top surface of the sidewall (22) and at least a portion of the lateral protrusion positioned above the sidewall (22) to adjust the tension in the tensioning device (39). 15. The port equipment according to any one of claims 10 to 14, wherein the support point on the sidewall (22) is formed by the top portion of the pile (25) serving as the foundation for the base structure (10), thereby allowing the weight from the supported float (11) to be transferred directly to the seabed (30) through the pile (25). 16. The port equipment according to any one of claims 10 to 14, wherein the support portion on the top surface of the sidewall (22) corresponds to or is closely associated with the upper end of the pile (25), the pile (25) supporting the base structure (10) and extending through the sidewall (22) and into the seabed (30). 17. The port equipment according to claim 15, wherein the pile (25) is arranged to terminate above the sea level (29) at the top surface of the sidewall (22). 18. The port equipment according to any one of claims 10 to 14, wherein the support (51) and the complementary support (52) are welded to each other.