CN102906339B - Auxiliary equipment stake is arranged in sea bed, offshore foundation structure and set up the method for offshore foundation - Google Patents

Abstract

The invention provides a kind of offshore foundation (1) of setting up on sea bed on sea bed, particularly set up the method being used for the offshore foundation that wind turbine is installed.In this process, the offshore foundation structure (1) comprising at least one supporting leg (7) to be arranged on sea bed and to be anchored in described sea bed (3) by the stake (10,13) extended to from described supporting leg in described sea bed (3).Described grappling realizes by described stake (10) punching being dug in described sea bed (3).

Description

Device for assisting installation of piles in seabed, offshore foundation structure and method for establishing offshore foundations

technical field

The present invention relates to equipment to assist in the installation of piles in the seabed. Furthermore, the invention relates to offshore foundation structures and methods of establishing offshore foundations.

Background technique

It is known to build monopile, casing constructions or tripod constructions on the seabed as foundations, in particular for offshore wind turbine installations. For example the monopile construction described in WO2009/026933 Al. For example US Pat. No. 5,988,949 and EP2067914A2 describe bushing configurations, and eg DE102004042066A1 describes tripod configurations.

The typical method of building foundations, especially those based on casing construction or tripod construction, is to prepare the seabed prior to laying the foundation, including leveling the seabed at different heights in order to obtain a horizontal formation. Furthermore, the method includes establishing very precisely positioned piles in the seabed, for example by positioning formwork structures with prefabricated or pre-positioned piles on the seabed. The piles are used as anchors for offshore foundations.

The pile is established by using, for example, a hydraulic driving device which drives the pile down into the seabed. When erecting a pile, a casing or tripod construction is placed over a portion of the pile (or, in the case of a tripod or casing construction, multiple piles) and the space between the legs and the pile is grouted to establish a solid Connection.

Contents of the invention

In view of the above state of the art, it is an object of the present invention to provide an advantageous device for assisting the installation of piles in the seabed. A further object is to provide an advantageous offshore foundation structure and method of establishing an offshore foundation.

The first object is achieved by a device for assisting the installation of piles in the seabed, where the piles are to be used for anchoring offshore foundations. Further objects are achieved by an offshore foundation structure as claimed in claim 7 and by a method for building an offshore foundation as claimed in claim 11 . The dependent claims contain further developments of the invention.

The device of the invention for assisting the installation of piles for anchoring offshore foundations in the seabed comprises a nozzle and means for generating a water jet from said nozzle. The water jets swirl the seabed material and thus create a low resistance to the pile to be positioned. Said device is integrated into said piles for anchoring offshore foundations. In this case, the post may comprise a tip in which the nozzle of the device is located. Alternatively, the device may be a separate device that swirls the seabed material. The pile then follows closely behind the device penetrating the flushed material.

The equipment to assist in installing the pile in the seabed may include a dredge control connected to the nozzle by, for example, one or more flexible pipes. In particular, if the device is integrated into piles for anchoring offshore foundations in the seabed, the dredging control device may be integrated into the piles. Alternatively, the excavation control device may be external to the pile.

The device of the invention facilitates drifting of piles into the seabed. In particular, by using the device of the invention, the installation of the piles does not require special vessels or heavy machinery. Furthermore, two or more devices of the invention can be operated in parallel so that two or more piles can be driven into the seabed at the same time, which saves time and thus costs.

Furthermore, the device of the present invention provides the opportunity to install an entire configuration, such as a tripod or casing configuration, in one go, thereby minimizing the time spent on expensive dedicated vessels for installation.

The inventive offshore foundation structure to be installed on the seabed, in particular for wind turbines, comprises at least one foot and piles for anchoring said offshore foundation structure in said seabed. Said offshore foundation structure, such as piles of the offshore foundation structure, comprises the device of the invention for assisting the installation of piles in the seabed. With a foundation structure designed in this way, the advantages mentioned with reference to the device for assisting the installation of piles in the seabed are all realized in the offshore foundation structure.

In a first embodiment of the offshore foundation structure, the structure comprises at least one hollow leg having an inner hollow space. A stake is located within the hollow space. Such a foundation structure may be positioned such that the feet are on the seabed and then anchored by driving piles into the sea. The offshore foundation structure of the present invention therefore overcomes the need for pre-installation of piles in the seabed in which the structure is provided. The pre-installed piles need to be positioned very precisely so that typically three or more legs of a tripod or casing structure can be placed on the ends of the piles protruding from the seabed. Therefore, preinstalling these piles is complicated. With the inventive offshore foundation structure according to the described embodiments, the anchoring process can be simplified to the point that no precise pre-installation of piles for anchoring the structure is required.

In another embodiment, an offshore foundation structure includes at least one leg having a foot and a pile extending from the foot. In other words, the pile is fixed to the foot so as to protrude from said foot towards the seabed. The piles are then driven into the seabed together with the foundation structure connected to the piles by means of the device for assisting the installation of the piles in the seabed. This means that the entire offshore infrastructure can be placed on and anchored into the seabed in a single process step, which saves time and thus costs. Due to the low resistance of the scoured seabed material, it is even possible to place the foundation on the seabed, propelled by the weight of the structure.

In the method of the present invention for establishing an offshore foundation on the seabed, in particular an offshore foundation for a wind turbine on the seabed, an offshore foundation structure comprising at least one outrigger is placed on the seabed, and by extending from the outrigger The piles into the seabed are anchored in the seabed. In the method according to the invention, at least one leg is anchored in the seabed by driving piles into the seabed. For driving the piles into the seabed, the device for assisting the installation of piles in the seabed according to the invention is used. The device may be integrated into the pile, or it may be an external device which swirls the material of the seabed so that the pile can penetrate into the excavated material by immediately following the device And was driven into the seabed.

In a first embodiment of the method according to the invention, the piles are punched out of the inner hollow spaces of the legs of the offshore foundation structure into the seabed after the offshore foundation structure has been placed on the ground.

An offshore foundation structure having piles extending from the at least one foot is positioned on the seabed. In this embodiment, an offshore foundation structure with piles is placed on the seabed and the piles are driven into the seabed, whereby the offshore foundation structure rests on the seabed together with at least one foot. In this embodiment of the method, anchoring the foundation structure and placing the structure on the seabed are carried out in a single process step, saving time and saving costs. Due to the low resistance of the excavated seabed material, the placement process can even be carried out by the weight of the structure.

In any embodiment of the method of the present invention, the apparatus for assisting installation of piles in the seabed of the present invention may be used to drive piles into the seabed. The equipment may be integrated into the pile or it may be a stand-alone equipment that excavates seabed material. In the latter case, the pile penetrates the excavated material immediately after the separate device.

Description of drawings

Other characteristics, characteristics and advantages of the present invention will become apparent from the following description of the embodiments in conjunction with the accompanying drawings.

Figure 1 shows a highly schematic view of a casing or tripod structure of an offshore wind turbine foundation.

Figure 2 shows a highly schematic view of a monopile structure of an offshore wind turbine foundation.

Figure 3 shows a part of a first embodiment of the offshore infrastructure of the invention.

Figure 4 shows a part of a second embodiment of the offshore infrastructure of the invention.

Detailed ways

Figures 1 and 2 show in highly schematic views a typical offshore foundation for a wind turbine on which the invention can be implemented. Figure 1 shows le using a casing structure or a tripod structure as the foundation of the foundation structure, and Figure 2 shows the use of monopiles as the foundation of the foundation structure.

The bushing or tripod structure 1 shown in Figure 1 comprises three hollow legs 7 each forming a tubular hollow base. Each leg 7 is equipped with an open longitudinal end 5 located in the foot 4 on the seabed 3 , so that this open longitudinal end 5 appears towards the seabed 3 . The legs 7 are slightly inclined relative to the vertical. The piles 10 protrude into the seabed 3 through the open longitudinal ends 5 of the legs 7 to form anchors for the foundation structure 1 . The interior of the leg 7, especially the space between the pile 10 and the inner wall of the leg 7, may be grouted in order to increase the stability of the structure.

Figure 2 shows a monopile structure used as a foundation structure. This foundation structure comprises as one of the main elements a tubular hollow foundation 14 having a foot 4 placed on the seabed 3 and an open longitudinal end 5 in the foot 4 . From this tubular hollow foundation 14 a pile 10 extends into the seabed 3 through an open longitudinal end 5 in the foot 4 forming an anchor for the tubular hollow foundation 14 . The inner space of the tubular hollow foundation 14, especially the space between the part of the pile 10 inside the tubular hollow foundation 14 and the inner wall of the tubular hollow foundation 14, can be grouted to increase the stability of the foundation.

The invention will now be described by way of exemplary embodiments. These embodiments are shown in Figures 3 and 4 and generally relate to an advantageous offshore foundation structure for a wind turbine tower and advantageous establishment of an offshore wind turbine tower foundation (such as a tripod or casing structure on the seabed, for example) )Methods.

FIG. 3 schematically shows a first embodiment of the invention in which, as an illustrative example, a casing structure 1 is established on the seabed 3 . The structure 1 is held in a fixed position on the seabed 3 by one or more piles 10 mounted in the seabed 3 by the legs 7 of the structure.

For this embodiment of the invention, the pile 10 is excavated to penetrate and position it in the seabed 3 .

The pile 10 of this embodiment comprises a plurality of nozzles 8 in the tip 6 of the pile 10, which make it possible to form a water jet 9 which swirls the material of the seabed 3 and thereby creates a low resistance to the pile to be positioned .

For another embodiment of the present invention, the dredging to swirl the material of the seabed 3 is performed by a dredging device other than the pile, that is, a separate dredging device is used to swirl the material of the seabed, and the pile Followed closely to penetrate the scoured material.

For various embodiments of the invention, the blowing is controlled by a blowing control device 11 connected to the nozzle 8 via, for example, one or more flexible tubes 12 . The excavation control device 11 can be integrated in the pile 10 or can be external.

This embodiment of the invention is therefore characterized in that the foundation structure, such as a casing or a tripod, is secured to the seabed by means of one or more piles which have been installed in the seabed by dredging.

The advantage of this embodiment is that it is easy to set up. Furthermore, the installation does not require a special vessel or heavy equipment for installation. Even further, for one installation process, more than one pile can be operated at the same time, so the process saves time.

Fig. 4 schematically shows a second embodiment of the invention. In this embodiment, the casing structure 1 is established on the seabed 3 as an illustrative example. The structure 1 comprises one or more piles 13 connected to the structure 1 , in particular to the feet 4 at the lower ends of the legs 7 . The pile 13 also comprises one or more nozzles 8 having the functions already described with reference to the first embodiment.

According to a second embodiment of the invention, the pile 13 is connected to the structure 1 before being positioned on the seabed 3 . During installation, the piles 13 are driven into the seabed 3 by dredging while carrying the structure 1 . This means that the punching of each pile 13 must be adjusted in order to push the entire structure into the correct erection position.

Thus, this embodiment of the invention is characterized in that establishing the foundation structure (eg casing or tripod) on the seabed is accomplished by driving one or more connected piles into the seabed by dredging.

An advantage of this embodiment is that the entire structure can be installed at the same time, thereby minimizing the time spent on expensive dedicated vessels for installation.

Although driving one or more piles into the seabed by scouring has been described in the context of casing or tripod structures, it can also be done in the context of a monopile structure as shown in Figure 2 (for example by using the referenced The piles depicted in Figure 3) are accomplished by driving the piles into the seabed by excavation in order to anchor the monopile structure. Alternatively, as with casing or tripod structures, a separate dredging device may be used that swirls the seabed material as the pile is driven into the seabed.

Claims (10)

Claims 1. An offshore infrastructure (1) mounted on a seabed (3) and comprising at least a leg (7) and stake (10, 13) with a foot (4), It is characterized in that, said stake (13) extends from said foot (4) and is secured to said foot (4); and A device for assisting the installation of said pile (10, 13), wherein said device comprises a nozzle (8) and means for generating a water jet (9) from said nozzle (8). 2. Offshore infrastructure according to claim 1, characterized in that the offshore infrastructure is an offshore foundation for a wind turbine. 3. The offshore infrastructure structure according to claim 1, characterized in that, The device for assisting mounting of the pile (10, 13) is integrated into the pile (10). 4. The offshore infrastructure structure according to claim 1, characterized in that, The device comprises a dredging control device (11) connected to the nozzle (8). 5. Offshore infrastructure according to claim 4, characterized in that, The excavation control device (11) is connected to the nozzle through one or more flexible pipes (12). 6. Offshore infrastructure according to any one of claims 1 to 5, characterized in that The stake (10) comprises a tip (6) in which the nozzle (8) of the device is located. 7. Offshore infrastructure according to claim 4 or 5, characterized in that, The excavation control device (11) is integrated into the pile (10). 8. A method of establishing an offshore foundation (1) on the seabed, wherein an offshore foundation structure (1) comprising at least one outrigger (7) is placed on the seabed and extends from said outrigger to said seabed anchored in said seabed (3) by piles (10, 13) in said seabed (3), It is characterized in that, anchoring said at least one leg (7) in said seabed (3) by driving said piles (10, 13) into said seabed (3); using an offshore infrastructure (1) according to one of claims 1 to 6; and The offshore foundation structure (1) is placed on the seabed with piles (13) extending from the at least one foot, and the piles (13) are excavated into the seabed (3), whereby The offshore foundation structure (1) is placed with the at least one foot (4) on the seabed (3). 9. The method of claim 8, wherein the method is establishing an offshore foundation for wind turbine installation on the seabed. 10. The method of claim 8, wherein, The equipment for assisting the installation of piles (10, 13) is a separate device for excavating material from the seabed, and the piles (10, 13) penetrate the excavated material immediately after the independent equipment.