JPH0134833B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suction anchor, and particularly to a suction anchor used for mooring large marine structures in deep water areas.

Generally, in order to moor a large marine structure in the ocean, it is necessary to install an anchor with a rough parking force of several hundred tons in a deep water area of several hundred meters.

When a steel anchor for a ship is used as a method to achieve such a purpose, the anchor becomes huge. Driving piles into the seabed is also effective, but the attached equipment becomes large.

There is a suction anchor that eliminates these drawbacks. This suction anchor is made of a cylindrical body with a closed top, which uses its own weight to achieve initial penetration (sinking to the seabed), and then uses a pump to drain the water inside the cylindrical body to the outside. The anchor penetrates using the negative pressure generated inside the body.

However, this kind of anchor cannot be used at all in the ground where the initial penetration cannot be achieved under its own weight, and a high-head pump is required to obtain a large negative pressure, but a high-head pump is has the disadvantage of being weak at absorbing mud and sand in seawater. Furthermore, with conventional suction anchors, unlike air removal, a large amount of water cannot be removed at once, so negative pressure can only be applied little by little.

The suction anchor of the present invention is designed to eliminate the above-mentioned drawbacks, and includes a cylindrical suction anchor body with a closed top, a guide portion that guides the sinking of the suction anchor body, It is characterized by comprising a jet water nozzle opening at the inner bottom of the suction anchor body, a pressurizing air hose, and a water and air suction pipe inserted into the suction anchor body.

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

In the figure, 1 is a cylindrical suction anchor body with a closed top, 2 is a power unit that supports this suction anchor body 1 via a chuck 3, 4 is a support ship, and 5 is a support ship 4 that supports the power unit. In the present invention, in order to vertically guide the power unit 2 up and down, the guide legs 6 are suspended vertically to the seabed, and a jet opening at the inner bottom of the suction anchor body 1 is shown. A water nozzle 7 is provided, and one end of a pressurizing air hose 8 is inserted into the suction anchor body 1 from its top, the other end is connected to a compressor (not shown), and one end of a water and air suction pipe 9 is also inserted. The other end is connected to a water and air suction mechanism (not shown) via a check valve 10.
Connect to. Since the suction anchor of the present invention has the above-described configuration, the anchor can be installed in the following manner.

(1) As shown in Fig. 3, jet water is jetted out through the nozzle 7 and water is sucked from the pipe 9 at the same time as the guide leg 6 lands, and the dead weight of the suction anchor body 1 and the power unit 2 and the jet water are Initial rooting is achieved through the power of

(2) As shown in FIG. 4, the interior of the suction anchor body 1 is pressurized via the air hose 8 by a compressor on the ship, and the water inside is discharged via the pipe 9.

(3) Stop pressurizing with air as shown in Figure 5,
Air inside the suction anchor body 1 is transferred to the pipe 9
released into the atmosphere via.

Due to the resulting negative pressure, the suction anchor body 1 penetrates into the seabed as shown in FIG.

If penetration is insufficient, repeat the above steps.

If the suction anchor of the present invention is used as described above, there are various advantages as described below.

Suction anchor body 1 by guide leg 6
Since it is guided, it is prevented from overturning, and it is also able to sink vertically, allowing it to cope with irregularities on the seabed.

In cases other than bedrock, initial penetration into the seabed can be achieved by using the suction anchor body 1's own weight and jet water in combination.

Since the jet water is spouted inside the suction anchor body 1, the interior can be excavated without disturbing the ground around the anchor. Therefore, when negative pressure is generated within the suction anchor body 1, water can be prevented from entering from the outer periphery, and penetration efficiency can be increased.

Since it is possible to generate a negative pressure equivalent to the depth of water within the suction anchor body 1, it is more effective at greater depths of water.

Compared to the case where water is sucked from inside the suction anchor body 1 to generate negative pressure, the inside of the body 1 is pressurized by air at the same time when water is sucked from inside the suction anchor body 1, so the water inside can be discharged quickly. After that, air is sucked in to generate a negative pressure, so a larger negative pressure can be generated, and this negative pressure can be generated rapidly.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the suction anchor of the present invention;
FIG. 2 is a perspective view thereof, and FIGS. 3 to 6 are explanatory views thereof. 1...Suction anchor body, 2...Power unit, 3...Chuck, 4...Support vessel, 5...
...Rope, 6...Guide leg, 7...Nozzle, 8...
...Air hose, 9...Pipe, 10...Check valve.

Claims (1)

[Claims] 1. A cylindrical suction anchor body with its top closed, a guide portion that guides the sinking of the suction anchor body, a jet water nozzle that opens at the inner bottom of the suction anchor body, and the suction anchor body. A suction anchor comprising a pressurizing air hose and water and air suction pipes inserted into the suction anchor.