JP2000108988A - Claw anchor installation method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high holding power by making claws easily penetrate even the sea bottom of hard soil. SOLUTION: A sea water jet pipe 9 is provided along the outer surface of each claw 3 of a claw anchor 1 formed by fitting the claws 3 to the lower face of an anchor body 2. A jet pump 6 is connected to the sea water jet pipe 9. When the claw anchor 1 is installed at the sea bottom 11, sea water jet 10 generated by driving the jet pump 6 is jetted toward the sea bottom 11 from the tip position of each claw 3 through the sea water jet pipe 9, and hard sea bottom soil is loosened to make the claw 3 penetrate it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for installing a claw anchor used for mooring a marine structure.

[0002]

2. Description of the Related Art An anchor used for mooring a marine structure such as a floating breakwater has a plurality of claws b directed downward on a lower surface of an anchor body a having a required weight, as schematically shown in FIG. When installed on the seabed, the claw b penetrates the seabed using only the own weight of the anchor body a and the claw b and the chain c attached to the anchor body a. Like that. Further, when the seabed soil in the area where the anchor is installed is hard, it is difficult to penetrate the seabed with the anchor's own weight alone. Therefore, a weight d is added as shown by a two-dot chain line.

[0003]

However, when the seabed soil is hard, it is not possible to make the claw b penetrate into the seabed by adding a small weight d depending on the soil quality, while the weight d is hardened. If it is too large, it may not be possible to add it technically.

[0004] Therefore, if an attempt is made to cope with an anchor without a claw, the holding force by the claw cannot be obtained, and it is necessary to increase the anchor's own weight in order to increase the holding force.
Since the anchor is huge, not only the production cost is increased, but also the production itself may be difficult. In addition, handling of the huge anchor may cause a problem at the time of installation.

[0005] Therefore, the present invention can easily penetrate the seabed even when the seabed soil is hard,
An object of the present invention is to provide a method and an apparatus for installing an anchor with a claw that can improve the holding force.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a jet pump for installing an anchor with a plurality of claws downward on the bottom of an anchor body on the seabed. Activate and inject a seawater jet stream from the tip position of the nail toward the sea bottom through the seawater injection pipe or the seawater injection flow path in the nail along the outer surface of the nail, so that the seabed soil at the tip of the nail is And a method and an apparatus for installing an anchor with a claw, in which the anchor body is lowered so that the claw penetrates into the seabed.

[0007] When the seawater jet stream is jetted from the tip of the nail to the seabed immediately before the nail comes into contact with the seabed at the time of installation of the anchor, even if the seabed is hard seabed soil, it is fluidized or blown off by the jet stream. Since it can be softened, the nail can be easily penetrated.

In addition, by making the jet pump detachable, it is possible to recover the anchor after installing it and use it for another purpose.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 (a), 1 (b) and 1 (c) show an embodiment of the present invention. For example, five nails 3 extending in a row are attached in a row, and an anchor ring 4 is provided on both front and rear (or left and right) side surfaces (or one side surface) of the anchor main body 2, and a plurality of anchor rings 4 are provided on both right and left (or front and rear) side surfaces In the anchor 1 with claws having the hooks 5 attached thereto, jet pumps 6 for jetting seawater are respectively arranged on both left and right side portions of the anchor body 2, and the jet pumps 6 are connected to connection flanges 7, respectively. And detachably connected to one end of the header tube 8 through the base, and guide the other end of each of the header tubes 8 to the lower surface of the anchor body 2 along the positions of the roots of the claws 3 in each row, Change The seawater injection pipe 9 branched from each header pipe 8 corresponding to the position of each claw 3 is guided downward along the outer surface of each claw 3 to a tip position which is the lower end of the claw 3, By driving the jet pump 6, seawater is sucked, and the jet stream 10 of seawater is jetted from the tip of the seawater jet pipe 9 toward the seabed 11 through the header pipe 8.

When the claw anchor 1 is installed on the seabed 11, the claw anchor 1 is entirely suspended. However, when the seabed 11 is made of hard soil, the tip of the claw 3 is attached to the seabed 11. Immediately before contacting the seawater, the jet pump 6 is driven to jet the seawater jet stream 10 from the tip of each seawater injection pipe 9. At this time, the seawater injection pipe 9 is
Is guided downward to the tip of the claw 3 along the outer surface of the claw 3.
0 will be injected.

As a result, the seabed soil near the position immediately below the claw 3 is fluidized by the action of the jet stream 10 of seawater,
Alternatively, the claws 3 can easily penetrate into the seabed because they are blown off. Therefore, even if the soil is hard on the seabed 11, it is possible to easily cope with the seabed 11, and it is possible to obtain the anchor 1 with claws that can obtain a high holding force even with a small size.

In the above, since the jet pump 6 can be cut off at the connection flange 7, the claw anchor 1 can be collected and reused after being installed on the seabed 11. Further, when the anchor 1 with claws is installed in a region where the jet stream 10 is not required to be jetted, the jet pump 6 may be separated in advance.

FIG. 2 shows another embodiment of the present invention. In a configuration similar to that shown in FIGS. 1 (a), 1 (b) and 1 (c), the claws 3 are made of steel pipe. Further, instead of having the seawater injection pipe 9 along the outer surface of the claw 3, the hollow portion inside the claw 3 is connected to the jet pump 6 via the header pipe 8 as a seawater injection flow path 9 '.

2, since the claw 3 can also have the function of the seawater injection pipe 9, the dedicated seawater injection pipe 9 can be omitted, and the structure can be simplified. Can be.

In the above embodiment, all the claws 3
Although the case where the seawater injection pipe 9 is guided and the seawater injection flow path 9 ′ is formed is shown, the invention is not limited to this, and only a part of the claws 3 may be used. The claw 3 shown in FIG. 1 can be made of any material such as a steel pipe or an H-section steel as long as it has a sliding resistance when penetrated into the seabed 11, and other ranges that do not depart from the gist of the present invention. It is needless to say that various changes can be made within.

[0017]

As described above, according to the method and the apparatus for installing a claw anchor of the present invention, when a claw anchor having a plurality of claws attached downward on the lower surface of the anchor body is installed on the seabed. , By operating a jet pump and injecting a seawater jet stream from the tip position of the nail toward the sea bottom through a seawater injection pipe or a seawater injection flow path in the nail along the outer surface of the nail. Because the anchor body is lowered and the claws are made to penetrate the seabed while unraveling the part of the seabed soil, even if it is hard soil, the claws can easily penetrate, with small size claws Even with the anchor, a high holding force can be reliably obtained, and by configuring the jet pump to be detachable, the clawed anchor can be recovered after installation and used for other work. It exhibits an excellent effect of.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows an embodiment of a seabed installation device for an anchor with a claw according to the present invention, wherein (a) is a schematic front view, (b) is a schematic side view, and (c) is a schematic bottom view.

FIG. 2 is a schematic side view showing another embodiment of the present invention.

FIG. 3 is a schematic view showing an example of a conventional anchor with a claw.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anchor with a claw 2 Anchor main body 3 Claw 6 Jet pump 9 Seawater injection pipe 9 'Seawater injection flow path 10 Jet flow 11 Sea bottom

Claims (4)

[Claims] 1. A seawater jet pipe along the outer surface of the nail or seawater in the nail when an anchor with a plurality of claws downwardly attached to the lower surface of the anchor body is installed on the seabed. By breaking the seabed soil at the tip of the claw by injecting a jet stream of seawater from the tip of the injection flow channel toward the seabed, the anchor body is lowered so that the claw penetrates the seabed while breaking the seabed soil at the tip of the claw. How to install an anchor with claw. 2. An anchor with a plurality of claws downwardly attached to a lower surface of the anchor body, a jet pump is mounted on the anchor body, and the anchor body is arranged along the outer surface of some or all of the claws. An installation device for an anchor with a claw, characterized in that a seawater injection pipe arranged up to the tip of the claw is connected to the jet pump. 3. An anchor with a plurality of steel pipe claws downwardly attached to the lower surface of the anchor main body, the anchor main body being equipped with a jet pump, and a part or all of the claws in a seawater jet flow path. An installation device for an anchor with a claw, characterized in that the seawater injection flow path is connected to the jet pump. 4. The installation device according to claim 2, wherein the jet pump is detachable.