JPH01315513A - Mooring method and mooring device for floating body offshore structure - Google Patents

Abstract

PURPOSE:To reduce the influence of waves on a floating body offshore structure by installing a mooring device consisting of both an outer shell having penetrating holes on its side surface and a mooring pillar, on the water bottom, so that the floating body offshore structure can be turnably connected to the pillar via a connector. CONSTITUTION:A mooring device 1 consisting of both an outer shell 2 in which a large number of penetrating holes 4 are opened on the side surface of a bottomed cylindrical body and a mooring pillar 3 which is integrally formed with the outer shell 2, is installed so as to be located on the water bottom. And the supporting shaft 11 of a connector 9 is turnably inserted, from above, into an inserting hole 6 having been bored on the top of the mooring pillar 3, and a floating body offshore structure 8 is turnably connected to the mooring pillar 3. Thus, the floating body offshore structure can be always turned and moved in a position where the influence of wind and waves is least.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of mooring a floating marine structure and a mooring device thereof.

BACKGROUND ART As a means for holding floating marine structures such as floating islands and offshore platforms in fixed positions on the ocean, it is generally known to moor them to anchors installed on the seabed using rope chains.

<Problems to be Solved by the Present Invention> The conventional mooring techniques for floating marine structures described above have the following problems.

<B> The installation position of the anchor shall be based on observational statistical data such as wind direction and wave direction in the sea area where the floating offshore structure is moored, with the condition that the floating offshore structure is oriented in a direction that minimizes the influence of waves and winds. determined.

However, marine weather conditions do not always match statistical data, so taking into account the risk factors, it is necessary to over-design anchors, even ignoring the increased construction costs and longer construction period.

<Mouth> When a floating marine structure is moored for a long period of time under severe marine weather conditions, there are concerns that the cable chain may break or the anchor may move laterally.

<C> Floating marine structures are moored toward a position where they are least affected by wind direction, wave direction, etc., but since they are directly exposed to waves, the influence cannot be ignored.

Against this background, there is a desire to propose a technology that can minimize the effects of waves on floating marine structures.

<Object of the Invention> The present invention has been made in view of the above points, and an object of the present invention is to provide the following mooring technology for floating marine structures.

<B> A mooring technique for floating marine structures, iji, that allows floating marine structures to be always moved in the direction where the influence of waves and winds is least, even if the direction of waves and winds changes.

(Mouth) A mooring technology for floating marine structures that can alleviate the effects of waves.

<Configuration of the present invention> An embodiment of the present invention will be described below.

First, a mooring device for a floating marine structure will be explained based on FIG.

<A> Mooring device The mooring device 1 is a gravity-type structure consisting of an outer shell 2 and a mooring strut 3 integrated with the outer shell 2.

The outer shell 2 is a cylindrical body with a bottom, and has a wave-dissipating function by opening a large number of four groups of through holes on its side surface.

A mooring post 3 is vertically installed in the center of the bottom plate 5 of the outer shell 2.

In order to allow the mooring device 1 to land on the seabed, the heights of the outer shell 2 and the mooring struts 3 need only be long enough for their upper ends to reach the water surface.

<Exit> Mooring device and mooring means of floating marine structure Mooring strut 3
A cylindrical cushioning material 7 is inserted into the insertion hole 6 formed in the upper part of the housing.

In the mooring device 1 according to the present invention, the rigid connector 9
The floating marine structure 8 is moored so as to be able to turn.

The connector 9 consists of a bifurcated connector main body 10 connected to the floating marine structure 8, and a support shaft 11 formed downward at the free end of the connector main body 10.

The support shaft 11 of the connector 9 is rotatably inserted from above into the insertion hole 6 of the mooring strut 3, thereby pivotally connecting the floating marine structure 8 to the mooring strut 3.

In short, it is sufficient if the floating marine structure 8 can be connected to the mooring strut 3 so as to be rotatable.

<Function>Kui> Adaptability to marine weather conditions As shown in Figure 2, the floating marine structure 8 moored to the mooring device 1
When waves and winds act from the direction of arrow A, the floating marine structure 8 in the figure receives an external force B from above and an external force C from below.
The turning force is applied by the difference between

Since the floating marine structure 8 is moored to the mooring device 1 via the connector 9 so as to be able to rotate freely, it receives the turning force generated by the difference between the external forces B and C, and moves as shown by the arrow A in FIG. Turn to the extension line of .

When the floating marine structure 8 turns and moves to the extension line of arrow A, the external forces acting on both sides of the floating marine structure 8 are balanced and it comes to rest.

Therefore, the floating marine structure 8 always moves to a position on the extension line of the arrow A on the rear side of the mooring device 1 where it is least affected by waves and wind.

<Exposure> Regarding the influence of waves As shown in FIG. 1, when a large wave is incident on the mooring device 1, this wave force is attenuated as it passes through the group of 4 through holes in the outer shell 2.

Therefore, the floating marine structure 8 located on the back side of the mooring device 1 receives the force of the attenuated (dissipated) waves.

<Other Embodiments> In the above embodiments, the case where the floating marine structure 8 is moored at one point of the mooring device 1 so as to be able to freely rotate has been described. It is also possible to restrain and moor.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be obtained.

(A) Even if the direction of the waves and winds changes, the floating marine structure can always be rotated and moved around the mooring device to a position where it is least affected by the waves and winds.

<Exposure> The mooring device has a wave-absorbing function, and since its cross-sectional shape is circular and has no directionality, it can attenuate the wave force of waves coming from any direction.

Therefore, the wave force acting on the floating marine structure moored to the back of the mooring device can be reduced.

<C> Since the direction of wave force acting on the floating marine structure can be specified, the external force acting on the floating marine structure can be accurately calculated, and mooring devices can be rationally designed.

(2) Since the mooring device is a gravity type, the danger of movement caused by dragging an anchor, etc. in the conventional method can be eliminated, and the floating marine structure can be moored safely and reliably.

4. Brief explanation of the drawings.

Figure 1: Longitudinal cross-sectional view of a mooring device for a floating offshore structure Figure 2:
An explanatory diagram of external forces acting on a floating marine structure before turning Figure 3: An explanatory diagram of external forces acting on a floating marine structure after turning

Claims (2)

[Claims] (1) A gravity-type cylinder with a group of through holes on its circumference is installed on the bottom of the water, a support is provided inside the cylinder and integrated with the cylinder, and a connecting device is used at the top of the support to create a floating marine vessel. A mooring method for floating marine structures that moor the structure so that it can rotate freely. (2) It consists of a bottomed outer shell and a mooring strut that stands integrally in the center of the bottom slab of the outer shell, with a large number of through holes on the side of the outer shell, and a floating marine anchorage installed on the top of the mooring strut. A mooring device for floating marine structures that forms a connecting part that allows the structures to rotate.