JPS5950805B2 - Method and device for laying sheet-like materials on the bottom of water - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for laying a sheet-like material such as a sheet or a net on the bottom of water, and an apparatus for carrying out the method.

In recent years, in order to improve the soft ground on the ocean floor during reclamation work, bank protection work, etc., it has become common to cover the soft ground with sand, or so-called sand matting.

In this case, it is effective to lay a sheet-like material on the seabed in order to prevent the sand from sinking in and to prevent sludge from flying up on the seabed and causing pollution.

However, this installation was a very troublesome work, as it had to be done without disturbing or blowing up the soft ground layers on the ocean floor, such as the sludge layer.

The conventional method of laying the material, for example, is to roll the sheet material to be laid, set it on the seabed, and have a diver push and roll it on the seabed to unroll it and lay it.

However, in the soft seabed ground, the roll is buried under its own weight, so it cannot be rolled. Even if it could be rolled, the diver would have to walk on the sheet that was unfolded to push the roll. There are dents left in the sheets that have been laid, making it impossible to lay them flat, and because they cannot be laid flat, extra allowance must be made for overlap with adjacent sheets, which also results in wasted material. It has the disadvantage that it increases in number.

Furthermore, if there is a sludge layer on the seabed, rolling the roll will disturb the harmful sludge layer and cause it to fly up, creating a very unfavorable situation.

Furthermore, the size of the sheet that a diver can push and roll is limited, which increases the number of seams, reducing work efficiency and requiring long hours of diving.
Not only does this worsen work efficiency, but it also poses health and safety problems.

Therefore, the method is to build a frame with bamboo or steel on the ground, stretch a large sheet over it, set weights if necessary, and then tow the frame suspended by a crane ship and sink it at the destination. was proposed.

However, this method has the disadvantage that a considerable amount of work space is required on the coast in order to assemble the frame.

In addition, the above-mentioned frame becomes an impediment to pile driving after the pile is sunk, and although it is fine if the sheet is made of net, if it is made of something with relatively low water permeability, such as cloth, it will take a very long time to sink the pile. In addition, it is susceptible to the effects of waves and tidal currents, so the accuracy of installation is poor.

Additionally, once the sheet tilts, the current will hit the sheet, causing it to sink rapidly and collide with the seabed.

This invention was made in order to eliminate the drawbacks of the conventional method as described above, and its purpose is to
With less diving work, large sheets can be produced with high efficiency and precision, without disturbing the shedding layer, and less susceptible to the effects of waves and currents, which can later become a hindrance to pile driving. An object of the present invention is to provide a method for laying a sheet-like material in water and a device for the same, which does not leave any residue behind.

Embodiments of the method and apparatus according to the present invention will be described below with reference to the drawings.

1 and 2 show the installed state of the device for implementing the method of this invention, the main parts of which are an anchor 1, a traction shaft 2, a traction device to be described later, and guide ropes 4, 4.
, buoyant bodies 5, 5, and towing means 6.

Here, the anchor 1 is attached to a belt-like sheet material 7 on the seabed.
This is for fixing one end 71 of the anchor 1.
consists of a pipe 11 having at least the width of the sheet-like material, and a weight 12 for mooring the pipe 11.

Since the pipe 11 is moored to the weight 12,
One end 71 of the sheet-like object 7 can be restrained in the horizontal direction over its entire width.

The traction shaft 2 is made of a pipe having a smaller diameter than the pipe 11.

The pipe is hollow and blinded at both ends to reduce its weight underwater.

The length of this traction shaft 2 is connected to the other end 72 of the sheet-like material 7.

Its length has at least the width of the sheet-like material 7.

The above-mentioned traction device is for moving the above-mentioned shaft 2 along the laying direction (arrow direction) of the above-mentioned sheet-like material 7, and although it will be illustrated later, side nets 31 are attached to both ends 21, 21 of the above-mentioned traction shaft 2, respectively. .31 are connected, and this side net 31.31 is towed by a winch installed on the shore.

The guide cables 4, 4 are for guiding the traction shaft 2 so as to maintain a posture perpendicular to the direction of movement thereof, and are arranged straightly at intervals corresponding to the width of the sheet-like material 7. They are laid in parallel.

Two buoyant bodies 5, 5 are provided, each floating on the water surface.

Cables 51, 51 are connected to each of the buoyant bodies 5, 5, respectively.

The elements 51, 51 are led to the transit 8 on the water, bypassing cable guide rings 52, 52 attached to both ends 21, 21 of the traction shaft 2, respectively.

This passage 8 is used as a towing means 6 for moving the buoyant bodies 5, 5 in synchronization with the movement of the towing shaft 2, as will be described later.

FIG. 3 shows the state of both ends 21, 21 of the traction shaft 2, and a metal fitting 9 as shown in the figure is attached to each end 21, 21, respectively.

In addition to the cable guide ring 52, the metal fitting 9 is provided with a guide ring 41 into which the guide cable 4 is loosely fitted, and a connecting ring 32 to which one end of the side net 31 is connected.

A shackle 33 is interposed between the side net 31 and the connecting ring 32, so that one end of the side net 31 is connected to the connecting ring 32.
It is detachable from 2.

FIG. 4 shows the state of the sheet-like material 7 before being laid, and the wide belt-like sheet-like material 7 is alternately folded back and folded.

The pipe 11 is connected to one end 71, and the traction shaft 2 is connected to the other end 72.

At both ends 71 and 72 of the sheet-like material 7, 30 cm
Eyelet holes are provided at the pitch of 1.

The pipe 11 and the traction shaft 2 are connected by being tied together at each eyelet hole.

Furthermore, a pullout line 13 for mooring to the weight 12 is attached to both ends of the pipe 11.

The sheet-like material 7 folded in this way and connected to the pipe 11 and the traction shaft 2 is assembled on the ground in advance and then transported to the installation destination.

Next, an example of a method for laying the sheet material 7 on the seabed using the apparatus described above will be described.

First, as shown in FIG. 5, the weights 12 are placed at a point where the sheet-like material 7 is to be laid, with the same spacing as the width of the sheet-like material 7.

Next, the guide cables 4, 4 are laid along the laying direction of the sheet-like material 7 from each weight.

Wire ropes are used for the guide ropes 4, 4, but this increases the overall weight considerably, and in a normal method, the wire ropes wind around the seabed and weaken, making it difficult to lay them straight.

Therefore, in this embodiment, as shown in FIG. 6, buoyancy buoys 4a, 4a...
Temporarily connect and install.

When laying this, one end of each guide cable 4 is attached to the weight 12.
However, the other end is extended and fixed at the coast 10.

Once the guide cables 4, 4 have been laid, as shown in FIG. 4, an auxiliary buoyancy body 53 is connected to the intermediate portion of the traction shaft 2, and the folded sheet-like material 7 is submerged.

Then, the pull rope 13 of the pipe 11 is connected to the previously sunk weight 12, and the guide ring 41 is connected to the guide rope 4.
Set each.

Furthermore, as shown in FIGS. 1 and 2, the cable 51 connected to the buoyancy body 5 is set in the cable guide ring 52.

Further, a side net 31 is connected to the connecting ring 32.

Next, the two cables 51, 51 connected to the buoyancy body 5 by bypassing the guide ring 52 are operated on the vessel 8 to ensure that the tow shaft 2 does not come off the seabed surface. Adjust so that it is horizontal while floating.

At this time, if necessary, both ends of the tow shaft 2 may be connected to the ship passage 8 using auxiliary ropes.

Once the preparations are completed as described above, the side net 31
is pulled by the winch 3 (see FIG. 5) as the traction device installed at the other end of the guide rope 4, and the traction shaft 2 is moved along the guide rope 4.

At the same time, the passage 8 moves the buoyant body 5 to the shaft 2.
Towed in the same direction in synchronization with the movement of the ship.

As a result, the sheet-like material 7 laid down in the above-mentioned folded state is sequentially unfolded and laid from the other end, as shown in FIG.

Then, as shown in FIG. 5, once the sheet-like material 7 is fully unfolded, a sand bag is thrown onto the sheet-like material 7 near the traction shaft 2 and the pipe 11 to fix it. The traction shaft 2 and pipe 11 are separated from the sheet material 7 and recovered.

By repeating the above method, the sheets 7 can be laid one after another as shown in FIG. 5. At this time, each sheet 7 is laid down as follows.
Since the diver does not have to push and roll the roll as in the past, the amount of diving work is greatly reduced, and therefore the work efficiency is significantly improved.

In addition, the traction shaft 2 is moved while pulling the other end of the sheet-like material 7, but since the buoyancy of the traction shaft 2 has been adjusted and the apparent weight has been lost, it may not sink into the soft ground of the seabed. The sheet-like material 7 is accurately unfolded by being pulled extremely smoothly without any friction.

This increases the laying accuracy of the sheet-like material 7, but
In the above-mentioned embodiment, two ends of the traction shaft 2 are laid in parallel with an interval corresponding to the width of the sheet-like material 7.
By guiding with a book guide rope, the above-mentioned laying accuracy is further improved.

Furthermore, since the sheet-like material 7 described above is folded by folding each other, by pulling the other end 72 with the traction shaft 2, it can be quietly unfolded without stirring up and disturbing the sludge layer on the seabed. I can do it.

Furthermore, since the sheet-like material 7 is spread out and laid on the seabed surface, it is hardly affected by waves or currents, and in this aspect as well, the accuracy of laying the sheet-like material is greatly improved.

In addition, since the weight of the towing shaft 2 is offset underwater, and because the diver does not rely on so-called human power to push and roll the roll of the sheet-like material, even large-sized sheet-like materials can be easily laid. Work efficiency can be further increased by reducing the number of joints.

Furthermore, since the sheet-like material laid on the seabed is a folded material that is unfolded on the seabed surface, nothing remains there that would impede pile driving.

As described above, in the present invention, after a belt-like sheet-like material in a state of being alternately folded and folded is lowered to the bottom of the water, one end of the sheet-like material is fixed, and the other end is fixed at least to the bottom of the sheet-like material. By horizontally towing the sheet-like material with a shaft that has a width and whose buoyancy is adjusted, the sheet-like material is deployed on the bottom of the water. With high efficiency and precision, without disturbing the sludge layer, without being significantly affected by waves or currents, and without leaving behind anything that would later become an obstacle for pile driving, it is possible to form a sheet on the bottom of the water without disturbing the sludge layer. You can lay things down.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an implementation state of the method and apparatus for laying a sheet-like material according to the present invention, Fig. 2 is a side view thereof, Fig. 3 is a side view showing an enlarged part of the same, and Fig. 4 5 is a side view showing the state of the sheet-like material before being deposited, FIG. 5 is a plan view showing the state of laying the sheet-like material, and FIG. 6 is a side view showing an example of the method of laying the guide cable. 1... Anchor device, 2... Traction shaft,
3... Winch as a traction device, 4... Guide cable, 5... Buoyant body, 6... Towing means, 7... Sheet-like material .

Claims (1)

[Scope of Claims] 1. After a belt-like sheet-like material that is folded up alternately is lowered to the bottom of the water, one end of the sheet-like material is fixed, and the other end is fixed at least as wide as the width of the sheet-like material. 1. A method for laying a sheet-like article on the bottom of water, characterized by spreading the sheet-like article on the bottom of the water by horizontally towing it with a shaft having a length and whose buoyancy is adjusted. 2. A patent claim characterized in that the fixed side end of the sheet-like object is attached to a shaft having at least the width of the sheet-like object, and both ends of this shaft are moored to a weight thrown to the bottom of the water. A method for laying a sheet-like material on the bottom of water according to item 1. 3. Laying of a sheet-like object on the water bottom according to claim 1 or 2, characterized in that the buoyancy of the shaft that pulls the sheet-like object is adjusted so that its weight in the water is offset. Method. 4. A traction rope is connected to both ends of a shaft that pulls the sheet-like object, and the traction rope is pulled from an extension direction of the sheet-like object in the unfolding direction. The method for laying a sheet material on the underwater bottom according to item 2 or 3. 5. Claim 1, characterized in that a buoyancy body is moored to a shaft that pulls the sheet-like object to adjust the buoyancy of the shaft, and the buoyancy body is towed in synchronization with the movement of the shaft. The method for laying a sheet-like material on the underwater bottom according to item 2, item 3, or item 4. 6. Claim 1, wherein the shaft that fixes one end of the sheet-like object and the shaft that pulls the other end of the sheet-like object are connected in advance before the sheet-like object is sunk to the bottom of the water.
The method for laying a sheet-like material on the underwater bottom according to item 1, 2, 3, 4, or 5. 7. Floating two buoyant bodies above the water, attaching cable guide rings to both ends of the towing shaft, and causing the ends of the cables individually connected to each buoyant body to bypass each of the guide rings. Claims 1, 2, 3, 4, 5 or 5, characterized in that the axis is kept horizontal by leading it out onto the water and manipulating the led out cable. The method for laying a sheet material on the bottom of water according to item 6. 8. An anchor for fixing one end of the sheet-like material at the bottom of the water, a traction shaft connected to the other end of the sheet-like material and having at least the width of the sheet-like material, a traction device for moving the shaft along the laying direction; two mutually parallel guide ropes for guiding the shaft so that the shaft maintains a posture perpendicular to the direction of movement; counterbalancing the weight of the shaft in the water; and a buoyant body that acts on the shaft so as to keep the shaft in a horizontal position, and a towing means that moves the buoyant body in synchronization with the movement of the shaft. Device. 9. The anchor is connected to one end of the sheet-like object,
9. The apparatus for laying a sheet-like article on the bottom of a water body according to claim 8, further comprising a pipe having a length at least as wide as the width of the sheet-like article, and a weight for mooring the pipe. 10. The apparatus for laying sheet-like materials on the water bottom according to claim 8, wherein the traction shaft is made of a pipe with both ends pre-processed, and both ends and the center of the sled are connected to a buoyant body.