JPH03151409A - Construction method for artificial island - Google Patents

Abstract

PURPOSE:To facilitate construction by towing a box, only the bottom of which is opened, sinking the box while the air or water in the box is discharged to be grounded, and then making the interior of the box negative pressure to press the box in the ground. CONSTITUTION:The lower portion of a box 1 comprising outer walls 2 and a ceiling plate 3 is opened, and the interior of the box is divided into a lot of air-tight chambers 5 by inner walls 4. Suction and exhaust pipes 7 and a suction and exhaust pump 11 are provided on the box 1, and connected to suction and exhaust ports 9 of the chambers through suction and exhaust valves 8. Further, filling cylinders 13 are provided on the ceiling plate 3, and water jet nozzles 6 are provided on the lower portions of the walls 2, 4. Subsequently, the box 1 is towed to a scheduled site for construction, and the air in the chambers 5 are discharged to sink the box. The chambers 5 are made negative pressure by the pump 11, the box 1 is pressed deep in the water bottom, and the water is jetted 6 to facilitate pressing-in. Accordingly, the construction can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of constructing an artificial island by providing a box in water such as the sea or a river.

<Prior Art> Conventional artificial islands include those using a bottom-mounted type or a seat-bottom type.

The bottom surfaces of these boxes are all flat.

In order to bring the box to the bottom of the water, a method is used in which water or soil is injected into the box and a load is applied.

There is also a skirt type method, which uses only the weight of the box to dig into the underwater ground.

Problems to be Solved by the Present Invention> The conventional construction methods described above have the following problems.

Let us consider the case where the bottom plate of the box is a flat plate type.

Since the bottom plate of the box is flat, the bottom surface must be flat in order for the box to land on the bottom of the water and remain stable.

Therefore, if the bottom of the water is uneven, the surface of the bottom of the water at the planned landing site must be leveled by excavating, using rubble, etc., to make it flat before the box lands on the bottom.

However, construction is difficult in ocean areas where the seabed surface is constantly changing due to waves and currents.

Moreover, in order to prevent sea level fluctuations caused by rocks and the like that would impede the construction work, it is time-consuming to construct temporary seawalls around the construction site.

〉When taking into consideration the impact caused by shear waves, earthquakes, etc. that occur after landing on the bottom, when using a conventional box, it is necessary to anchor the box after landing on the bottom of the water in order to maintain stability. be.

In this case, the box shall be fixed to the bottom of the water by the use of stakes or anchor chains.

Kuha> It is also necessary to take measures against scouring around the box caused by ocean currents (tidal currents) and waves.

In conventional boxes, immediately after installation, it is necessary to immediately throw in sand bags or rubble to prevent scouring.

Kuji〉Currently, stability, sustainability, and
It is desired to propose a box that has durability and is easy to construct.

Purpose of the Invention The present invention was made to solve the above problems, and provides a method for constructing an artificial island that is stable, sustainable, durable, and easy to construct. 11 (for the purpose of

Configuration of the Present Invention> An embodiment of the present invention will be described below with reference to the drawings.

Box Figure 1.2 shows an example of a box related to the present invention.

The box 1 is composed of an outer wall 2 surrounding the four sides and a ceiling plate 3 on the upper part of the outer wall 2, and is opened at the lower part, and the inside thereof is partitioned by an inner wall 4.

As a result, the chamber is divided into a number of airtight chambers 5 surrounded by the ceiling plate 3, the outer wall 2, and the inner wall 4, the openings of which are sealed by the water surface.

The box 1 is made of steel, reinforced concrete, or a combination thereof, and can be circular, square, or polygonal.

Exit〉Suction and exhaust device A suction and evacuation device is provided on top of the box l.

The suction/exhaust device includes a plurality of suction/exhaust pipes 7 and a suction/exhaust pump 1.
1 and more.

A suction/discharge hole 9 is provided in the upper part of each airtight chamber 5, and a suction/discharge pipe 7 is connected to the suction/discharge pipe 7 through a suction/discharge pipe valve 8.

A collection pipe 1 that collects and merges each suction and exhaust pipe 7.
Attach 0.

One suction/discharge pipe 7 that joins together at the collecting pipe 10 is connected to a suction/discharge pump 11 with a suction/discharge valve 8 in between.

Kuha〉Filling cylinder The filling cylinder 13 is provided on the ceiling plate 3 above the airtight chamber 5.

The filling cylinder 13 is configured such that the earth supply valve 12 is attached to the upper side and the lower side is open.

This filling cylinder 13 is for injecting earth and sand.

(2) Water Jet Nozzles Several water jet nozzles 6 are provided at the lower part of each outer wall 2 and inner wall 4.

This water jet nozzle is configured to spray when the outer wall 2 and inner wall 4 are press-fitted into the ground.

Effect〉 Next, the function of the box 1 will be explained.

Towing: Float the box 1 that has been constructed in advance on the sea, river, etc.

Next, the artificial island is towed by a ship or the like to the planned construction site, and the box 1 is lowered there.

Exit> Exhaust water is discharged through the suction/discharge hole 9 provided in the ceiling plate 3 of the settling box 1, and the box 1 with its lower part opened is set down.

The airtight chamber 5 is filled with air compressed at high pressure.

Therefore, when the suction and exhaust pipe valve 8 is opened, the air in the airtight chamber 5 is rapidly discharged upward.

As the air in the airtight chamber 5 is discharged, the box 1 begins to sink.

When discharging, the intake and exhaust pipe valves 8 are opened and closed for each airtight chamber 5 to balance the box 1.

The discharged air passes through a plurality of suction/exhaust vibes 7 and suction/exhaust pipe valves 8, and joins together at a collecting pipe 10.

The combined air at the collecting pipe 10 passes through the suction and exhaust pump 11 and is discharged as is.

<C> Load increase You may want to press fit the box deeper.

At that time, the suction/discharge pump 11 is operated.

With the operation of the suction pump 1, the pressure inside the airtight chamber 5 gradually becomes negative.

Then, the load increases due to the atmospheric pressure from above, and the outer wall 2 and inner wall 4 of the box 1 are press-fitted deeper into the water.

If the water jet 6 provided at the lower part of the outer wall 2 and inner wall 4 is injected during press-fitting, surrounding earth and sand can be diffused and press-fitting can be carried out smoothly.

Follow the steps above to ensure that the box is firmly planted on the bottom.

<2> After the press-fitting of the earth and sand filling box is completed, earth and sand may be injected from the filling tube 13.

Pressure-receiving resistance increases by injecting earth and sand.

As a result, uneven subsidence that may occur in the long term can be prevented.

Kune〉Water loading Additionally, higher live loads may be required.

In that case, an additional wall is installed above the ceiling plate 3 of the airtight room 5,
The wall forms a frame, and water is loaded within the frame.

This results in an even larger applied load.

Kuhe〉Expansion of the box With the operations described above, the bottoming of one box 1 is completed.

If you want to expand the area of this box, connect an additional box to the existing box 1.

This makes it possible to expand the area of the box.

<Effects of the Present Invention> As explained above, the present invention provides the following effects.

After the body weight has reached the bottom, there are cases where you want to make sure that it hits the bottom even deeper.

In this case, according to the present invention, by creating a negative pressure in the airtight chamber using a suction/exhaust device, the box can be press-fitted deeper into the water bottom.

<Exposure> Conventional boxes using the seat-bottom type and bottom-mounted type have flat bottom plates.

Therefore, large offshore machinery such as excavators and pile driving machines, as well as a fleet of ships, are required to flatten the planned landing site before the ship hits the bottom.

However, the bottom of the case of the present invention is open.

Therefore, there is no need to excavate or remove rubble before landing on the bottom.
Construction can be carried out using only small-scale construction machinery, mainly consisting of suction pumps.

In addition, since the above-mentioned work is not necessary, there is no need for temporary seawalls or the like to be constructed to prevent changes in the sea level due to waves, currents, etc. in the surrounding sea area.

Therefore, it is possible to achieve great economic efficiency in construction, and the construction period can be extremely shortened.

(c) The settling of the box is performed by exhausting the air in the airtight chamber by opening and closing the suction and exhaust pipe valves on each airtight chamber.

Therefore, the inclination of the entire box can be easily corrected by opening and closing each suction/exhaust pipe valve and adjusting the discharge of air in the airtight chamber.

(2) In the present invention, by creating a negative pressure inside the airtight chamber,
Press the box deeply into the bottom.

Therefore, the stability of the box can be maintained even if it is scoured.

Kuho〉The supporting capacity of only both walls may be insufficient.

In that case, inject earth and sand into the airtight chamber from a filling tube installed on the ceiling panel of the airtight room.

This allows the receiver to have supporting force over the entire area of the box.

Kube〉With conventional boxes, it was impossible to repurpose them.

However, the case of the present invention can be repurposed, and one possible method for this purpose is to pressurize water or air into the airtight chamber and re-float it.

<g> Even bigger i3! Sometimes a load is required.

In that case, an additional wall will be installed above the ceiling board of the airtight room.

This is made possible by forming a frame using the walls and placing water inside the frame.

Kuchi〉There is no need to excavate the bottom of the water, remove rubble, etc. to level it before landing on the bottom.

Therefore, there is no need to worry about destruction of the surrounding environment during the above treatment.

[Brief explanation of the drawing]

Claims (1)

[Claims] (1) Consisting of a box with only the bottom open and a discharge means for discharging the air or water inside the box, the box is towed, and the box settles while discharging the air or water inside the box and lands on the bottom. This method of constructing an artificial island involves creating negative pressure inside the box and press-fitting the box into the ground.