JPS6226371B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing an ultra-large diameter thin-walled shell and a floater for the installation method.

Diameter for construction of seawalls, breakwaters, artificial islands, etc.
The prefabricated steel sheet pile construction method is currently being used, which involves assembling cells approximately 20 meters long and 28 meters high using steel sheet piles, transporting them to a predetermined location, and then driving them. In addition, shells with a watertight membrane at the bottom and relatively thin walls exceeding 20 m in diameter and height are placed side by side in close contact with each other in seawater at a depth of 20 m or more, and each shell is filled with earth and sand. It can be installed in the form of a breakwater, or as a peripheral wall in the same way as above.
A new method of constructing an artificial island by pouring earth and sand inside the surrounding wall is also under development.

The prefabricated steel sheet pile construction method described above requires a large dedicated barge, and in the case of shell sinking, currently 1000~
Large crane ships that can lift 2,000 tons and huge barges with a payload of over 10,000 tons are used at sea, but the costs (losses, etc.) for this are extremely high, and such large, dedicated offshore structures are not suitable. There is a need for the development of a simple method for transporting and depositing shells that does not require the use of a machine.

The present invention solves the problems of the conventional shell transfer and sinking methods described above, and provides a simple method for installing an ultra-large diameter thin-walled shell that can be carried out without using a large crane ship or a large barge, and a floater for the installation method. The purpose is to

The installation method of the ultra-large-diameter thin-walled shell of the present invention is to install the ultra-large-diameter thin-walled shell at a position other than the installation position along a split-type annular floater formed by combining a plurality of divided unit parts that are detachable and capable of pouring water into a ring. Installed at a location means assembling it upside down, attaching a split annular floater to the lower part of the super large diameter thin shell, and floating the super large diameter thin shell using the buoyancy of the split annular floater in a state of shallow stagnant water. A towboat is used to inject water into a part of the split-type annular floater near the installation location, and the ultra-large-diameter thin-walled shell is tipped over so that it is in the normally installed state. This method is characterized by pouring water into the floater to sink an ultra-large diameter thin shell. However, the floater used in the above construction method is a split-type annular floater that can be detached and attached to the shell to be submerged and can be used to pour water into the shell. It consists of high-pressure-resistant sections made of floating bodies and a connecting member that connects these sections, and each section is equipped with equipment for pouring water, and its divided unit parts are divided into low-pressure-resistant floaters and high-pressure-resistant floaters. Each floater is equipped with a device for pouring and draining water.

In the present invention, an ultra-large-diameter thin-walled shell is installed at a location other than the installation position, with an ultra-large-diameter thin-walled shell along a split-type annular floater formed by combining a plurality of divided unit parts that are detachable and capable of being filled and drained into an annular shape. It is assembled in an overturned state, a split annular floater is attached to the lower part of the super large diameter thin shell, and the super large diameter thin shell is floated by the buoyancy of the split annular floater and towed in shallow and stagnant water.
There is no need for a large dedicated barge that has been conventionally used to transport ultra-large-diameter, thin-walled shells assembled at locations other than the installation location at sea.

In addition, the ultra-large-diameter thin-walled shell that had been towed to the vicinity of the installation position was injected with water into a part of the split-type annular floater to overturn it so that it was in the normal installation state, and then moved to the predetermined installation position while still in the installed state. Since the ultra-large-diameter thin-walled shell is sunk by injecting water into the annular floater, the large crane ship and large barge that were conventionally used to sink the ultra-large-diameter thin-walled shell are no longer necessary.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Figure 1 shows the shell in a floating state with a split annular floater attached to it. In the figure, a is a side view;
b and c are plan views, and S is a cylindrical or polygonal shell which can be made of steel plate, plastic, reinforced concrete, prestressed concrete, hybrid, etc. F ₁ is an annular inner floater that is detachable from the shell S and can be filled with water, and F ₂ is an annular outer floater that is also detachable and can be filled with water. Figures a and b show an example of a cylindrical shell, and figure c shows an example of a polygonal shell.

Inner floater which is a split annular floater
_F1 is made up of a combination of a plurality of divided unit parts, and has at least enough buoyancy to support the weight of the shell S and prevent it from sinking. It can also be used as a jig when assembling a floating barge, etc.). Therefore, the shell S is assembled along the outside of the inner floater F ₁ in an upside-down state compared to the installed state. and,
The inner floater F ₁ is attached to the lower part of the shell S assembled in this way.

The outer floater F ₂ is also a split annular floater, in which the height of the shell S is larger than the diameter.
If the inner floater F ₁ alone causes the shell S to become unstable in a floating state, it is attached to the lower position of the shell S in the same way as the inner floater F ₁ for stabilization purposes. This outer floater F ₂ does not necessarily have to be in a continuous annular shape as shown in FIG. 1, but may be arranged in an annular shape as shown in FIG. 2 but not continuous. In FIG. 2, S is a shell, _F2 is an outer floater, and tb is a tightening/release fitting such as a turnbuckle.

As mentioned above, the installed state is different from the installed state when the shell S is assembled upside down and supported by floaters _F1 and _F2 , and then floated and towed in the state shown in Figure 1a (in shallow water). and move it to a place with greater water depth near the installation location. Since the Ciel S is towed in shallow and tidal conditions, the Ciel S can be towed smoothly, and unlike the conventional prefabricated steel arrow method, a large dedicated barge required for cell transfer is not required. You won't have to use it. Therefore, the expense of a dedicated barge becomes unnecessary.

Next, use the procedure shown in Figure 3 a to b to
to be deposited.

That is, water is poured into a portion of the floaters F ₁ and F ₂ to make the shell S unstable and gradually overturn it. Figure 3a shows a state in which the shell S has begun to tilt due to water being poured into the floaters F ₁ and F ₂ , b shows a state in which it has fallen further, and Fig. 3 c shows a state in which it has completely fallen down. Water is injected into some of the inner and outer floaters F ₁ and F ₂ , but depending on the stability of Ciel S itself, water may be injected only into the outer floater F ₂ or the inner floater F _{1 .}
Water may be injected into only a portion of the area. At this time, the inner floater creates enough buoyancy to prevent Ciel S from sinking.
Leave it in _F1 .

When the shell S completely overturns as shown in Figure 3c, the shell S becomes properly installed, and also takes a big swish, and the center of gravity G of the shell S becomes below the center of buoyancy B, resulting in a very stable state. In this state, the outer floater
If F ₂ is used, remove it and collect it, adjust the stuttering by appropriately draining the inner floater F ₁ , and move Ciel S to the predetermined installation position. Figure 3 d is the outer floater
The figure shows the state in which F ₂ has been removed and Ciel S has been moved to the specified position.

Next, water is poured into the inner floater F ₁ to sink Ciel S and bring it to the bottom.

In order to sink Ciel S, Ciel S is towed near the installation position, water is poured into parts of the floaters F ₁ and F ₂ , the Ciel S is tipped over so that it is in the normal installed state, and the Ciel S is moved to the predetermined installation position in the installed state. By injecting more water into floaters F ₁ and F ₂ to sink Shell S, there was no need to use a large crane ship or a huge barge, which was required in the case of conventional shell sinking. Become. Therefore, there is no cost to use them.

After the shell hits the bottom, the inner floater F ₁ is removed and recovered, but this can be done immediately after it is sunk, or
It may be removed after pouring earth and sand into the shell to make the water shallower and easier to work with. After the shell is submerged, the floater _F1 is near the water surface, so it can be easily recovered and used repeatedly for the next shell assembly and transfer.

Next, the floater used in the construction method of the present invention will be described. The floater is of a split type, which can be combined into an annular shape and attached to the shell, and can be separated and removed, and is configured as a split annular floater that can be filled with water. As a result, the floaters F ₁ and F ₂ are drawn deep into the water when the shell S is overturned as shown in FIGS. 3a and 3b, and the portions that maintain residual buoyancy are subjected to high water pressure. If the entire floaters F ₁ and F ₂ were made to be able to withstand this external pressure, they would be heavy and expensive, and a large recovery device would be required. As a countermeasure against this, in the present invention, the divided unit parts of the floaters F ₁ and F ₂ are configured by combining two sections, a section that can withstand low pressure and a section that can withstand high pressure, or a floater that is resistant to high pressure and a section that is resistant to low pressure. The floater is arranged in a ring shape in combination with a floater. An example of the inner floater _F1 is shown in FIGS. 4 and 5.

In FIG. 4, figure a is a plan view of the divided unit portion of the inner floater _F1 , figure b is a front view, and figure c is a sectional view. In the figure, L is a floating body made of steel or synthetic resin that can withstand low pressure of about 1 atmosphere (low pressure resistant section)
In this case, T indicates a stiffener. H is a cylindrical or spherical floating body (high pressure resistant section) made of steel or synthetic resin that is lightweight and can withstand high pressure. C is a connecting member that connects the two sections. In FIG. 5, L is a low-pressure resistant floater, H is a high-pressure resistant floater (both form a division unit part), and J is a joint part. In Figure 4, one floater (unit part) consists of a low pressure resistant section and a high pressure resistant compartment, but in Figure 5, the low pressure resistant floater (unit part) and the high pressure resistant floater (unit part) are arranged as appropriate. These are arranged to form an annular floater.
In FIG. 5, L and H are arranged alternately, but the arrangement is not limited to this. The joint portion J is provided with a mechanism to facilitate attachment and detachment of the floater.

The total effective buoyancy of the high pressure resistant floater (or section) is planned to be greater than the total underwater weight of the submerged shell, the underwater weight of the flooded floater, the underwater weight of accessories, etc. Although not shown, the inner floater F ₁ has a water injection pipe for water injection and drainage,
It is equipped with compressed air pipes, vent pipes, valves, control equipment, etc. (not shown). However, with the above configuration, the buoyancy can be adjusted by pouring water,
To prevent Ciel from falling suddenly and to allow it to fall gradually and sink.

By the way, if part of the floaters F ₁ and F ₂ are injected and the shell S is overturned, the floater
Parts of F ₁ and F ₂ are drawn deep into the water, and the part that retains residual buoyancy is subjected to high water pressure. For example, the inner floater F ₁ has a divided unit part that is composed of a low-pressure resistant section and a high-pressure resistant section. Or, since it is configured in an annular arrangement by combining the divided unit parts of the high pressure resistant floater and the low pressure resistant floater, when Ciel S is overturned by injecting water into the low pressure resistant compartment or the low pressure resistant floater, the high pressure resistant compartment Alternatively, the high-pressure resistant floater can of course withstand high water pressure, and the low-pressure resistant section or low-pressure resistant floater can also withstand high water pressure because water is injected inside. Therefore,
The inner floater F ₁ can be constructed by configuring the divided unit parts of the inner floater F 1 into a low pressure resistant section and a high pressure resistant section, or by combining the divided unit parts of the high pressure resistant floater and the low pressure resistant floater to form an annular arrangement. Compared to a structure in which the entire structure of ₁ is constructed to withstand high pressure, it weighs less and can be produced at a lower cost.

Inner floater described above outer floater _F2
Of course, it can be constructed in the same way as _F1 and used in the same way.

As explained above, the present invention installs an ultra-large-diameter thin-walled shell at a location other than the installation location along a split-type annular floater formed by combining a plurality of split unit parts that are detachable and capable of filling water in an annular shape. is assembled upside down, a split annular floater is attached to the lower part of the super large diameter thin shell, the super large diameter thin shell is floated by the buoyancy of the split annular floater, and towed in shallow and stagnant water. Water is poured into a part of the split-type annular floater near the installation location, the ultra-large diameter thin-walled shell is tipped over so that it is in the normally installed state, moved to a predetermined position in the installed state, and water is poured into the split-type annular floater. Since the ultra-large-diameter thin-walled shells are sunk, the ultra-large-diameter thin-walled shells can be transported smoothly at sea without using the large specialized barges that were conventionally required. The project can now be carried out safely without the need for large crane ships or large offshore construction machines such as the large Birch.
This has the effect of reducing costs and improving work efficiency.

In addition, the floater used for transporting and sinking ultra-large diameter thin-walled shells is a split-type annular floater that can be attached and detached to the shell to be sunk and water can be poured into the shell, and the split unit portion is made of a floating body that can withstand low pressure. It consists of a high-pressure resistant compartment consisting of a low-pressure resistant compartment and a floating body that can withstand high pressure, and a connecting member that connects these two compartments. It consists of a low-pressure floater and a high-pressure resistant floater, and each floater is equipped with equipment for pouring and draining water, so when using the floater for transferring and sinking ultra-large diameter thin-walled shells, the entire floater can withstand high pressure. It has the advantage that it is lighter in weight and can be produced at a lower cost than those made using the same method.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a state in which the floater is attached to the shell, in which a is a side view and b and c are plan views. FIG. 2 is a plan view illustrating a discontinuous arrangement of floaters, and FIGS. 3 a to 3 d are explanatory views showing the procedure for sinking a cylindrical shell. Figure 4 is a diagram showing an example of the structure of a unit part of a floater, where a is a plan view and b
is a front view, and c is a cross-sectional view. FIG. 5 is a plan view showing an example of a combined arrangement of floaters. F ₁ : Inner floater, F ₂ : Outer floater,
S: shell, G: center of gravity, B: center of buoyancy, L: low pressure resistant floater (compartment), H: high pressure resistant floater (compartment), C: connecting member, T: stiffener, J: joint part, tb: tightening. Open fittings.

Claims (1)

[Claims] 1. What is the installation state of an ultra-large-diameter thin-walled shell at a location other than the installation position along a split-type annular floater formed by combining a plurality of divided unit parts that are detachable and capable of filling and draining water in an annular shape? Assemble it upside down,
A split-type annular floater is attached to the lower part of the ultra-large diameter thin-walled shell, and the ultra-large-diameter thin-walled shell is floated by the buoyancy of the split-type annular floater and towed in shallow water. Water is poured into a portion of the shell, the ultra-large-diameter thin-walled shell is tipped over so that it is in the normal installation state, and the ultra-large-diameter thin-walled shell is moved to the predetermined installation position in the installed state, and water is poured into the split type annular floater to sink the ultra-large-diameter thin-walled shell. This is an installation method for ultra-large-diameter thin-walled shells. 2. The method for installing an ultra-large-diameter thin-walled shell according to claim 1, in which an ultra-large-diameter thin-walled shell is assembled along the outside of a split-type annular floater so that the split-type annular floater becomes an inner floater of the ultra-large-diameter thin-walled shell. . 3. The split type annular floater comprises an inner floater attached to the inside of the ultra-large diameter thin shell and an outer floater attached to the outside of the ultra large diameter thin shell. Installation method for thin-diameter shells. 4. A split-type annular floater that can be attached and detached to the shell to be submerged and capable of pouring water into it, and its split unit parts include a low-pressure resistant section consisting of a floating body that can withstand low pressure, a high-pressure resistant section that consists of a floating body that can withstand high pressure, and a high-pressure resistant section consisting of a floating body that can withstand high pressure. A floater for an ultra-large-diameter thin-walled shell installation method, which is composed of a connecting member that connects both compartments, and each compartment is equipped with equipment for pouring and draining water. 5 A split-type annular floater that can be attached and detached to the shell to be submerged and capable of pouring water, the divided unit portion consisting of a low-pressure resistant floater and a high-pressure resistant floater, each floater being equipped with a device for pouring water. A floater for the installation method of ultra-large diameter thin-walled shells.