JPS6132455B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an underwater foundation construction method using a diaphragm type buoyant structure.

Most of the construction of breakwaters, sea walls, and reclamation work is carried out using the submerged box method.In reclamation work, the area around the reclamation site is enclosed using the submerged box method, the water inside is removed, and earth and sand are brought in for reclamation. However, in the past, the submarine box was first towed to its destination, and for this purpose a steel lid G was applied to the top surface of the box A' to seal the contact surface with the box, as shown in the explanatory diagram in Figure 1. ,
Furthermore, an air supply device P is installed on the top surface to send air into the interior to generate buoyancy and enable towing, but the airtightness between the top cover G and the box A′ is insufficient, and sometimes air pressure needs to be replenished. Air supply device P is essential;
In addition, setting up this air supply system is expensive, and in order to install the box on the seabed or the bottom of the water, the part H where the bottom of the box comes into contact with the seabed M must be constructed by diving to level the ground. This requires a large amount of cost. (L is the sea level) Usually, in coastal reclamation work, etc., the present invention also uses a combination box C as shown in the explanatory diagram of Fig. 2.
For example, by connecting boxes A and B, an appropriate number of boxes are connected in a row, and the third box is called D.
As shown in the explanatory diagram of the figure, a large number of them are lined up and surrounded on the outer periphery of the target landfill F, adjacent to each other. E is the coastline.

By using a diaphragm-type buoyant structure as the structure of the submersible for such construction, it is possible to carry out construction much more easily and at lower cost than the conventional construction method described above.

Figure 4 is a plan view of a diaphragm type buoyant structure used in the construction method of the present invention.The outer periphery is made of iron or concrete and has a shape such as A in A or B in B, and Figure 5 A and B are respectively Boxes A and B
This shows an example of a combination of the following. Figure 6 is the 4th
In the cross-sectional view of Figure A or B, 1 is a steel or concrete box, 2 is a steel lattice partition provided in the hollow near the bottom, 3 is a synthetic rubber-coated cloth diaphragm, and 4 is a diaphragm made of synthetic rubber.
is a backing plate for fixing the diaphragm 3 to the case wall near the bottom of the inside surface of the case 1 by tightening bolts. 8 is a bolt tightening part. The space inside the lower surface of the lattice partition 2 of the box 1 is made airtight and watertight by a diaphragm 3, and the diaphragm 3 made of synthetic rubber-coated cloth that can withstand the required water pressure is connected to the shaped steel lattice partition 2.
Since the diaphragm 3 is supported by air inside the diaphragm 3, it is possible to prevent water from entering the spaces a, b, c, and d in FIG. Box 1 can be made to float by determining the positions b and c (positions of the shaped steel lattice partitions) so that the buoyant force generated when the space is submerged below the sea surface is equal to the weight of the box. and can be towed to a desired location (in the ocean area). This diaphragm type buoyancy structure typically has a shape as shown in Figure 4, and is made up of a combination of A and B in Figure 5 in close contact as shown in combination C (Figure 2), and a plurality of these. D
You can connect it like this, tow it, and set it as your destination. As shown in Fig. 3, the buoyant structures are set one after another as destinations, and the diaphragm 3 is placed by pouring fresh concrete 5 from above the structure through the partition grid 2 made of shaped steel as shown in the explanatory diagram of Fig. 7. The structure can be lowered downward and fixed in response to the unevenness of the seabed 6. That is, there is no need to set the foundation by diving as in the past, and there is no need for an air supply device for towing, making setting the structure sinking extremely simple and economical, and making it possible to progress the construction work in a short time.
Of course, as shown in Fig. 3, after the area around the landfill destination is divided by such a structure, the seawater inside the area is removed and the earth and sand are brought in to complete the landfill.

[Brief explanation of the drawing]

Figure 1 is an explanatory cross-sectional diagram of the structure of a submersible used in conventional embankments and land reclamation, Figure 2 is an explanatory diagram of the towing method of the box, and Figure 3 is the construction of a submersible in coastal reclamation. 4A and 4B are plan views of the diaphragm type buoyancy structure used in the method of the present invention,
Fig. 5 is an explanatory plan view showing a combination of structures of different shapes, Fig. 6 is an explanatory cross-sectional view of a diaphragm type buoyancy structure used in the present invention, and Fig. 7 is an illustration of a method for installing the structure on the seabed. It is an explanatory diagram. 1... Buoyancy structure, 2... Steel lattice partition, 3
...Diaphragm, 4...Bolt tightening plate, 5
... Ready-mixed concrete, 6 ... Seabed, 7 ... Filling sealant, 8 ... Bolt tightening section, 9 ... Sea surface, A,
B...Boxes with different cross-sectional shapes, C...Combination box in which boxes A and B are connected, D...Collection and connection of combined boxes C, a, b, c, d...Sea surface and The positioning point of the space formed by the partition inside the box,
E...Coastline, F...Reclaimed land.

Claims (1)

[Claims] 1. In foundation work on the seabed or under water, such as for breakwaters, a shaped steel lattice partition is installed near the bottom of the hollow part of an iron or concrete box, and a synthetic rubber-coated cloth partition is installed on the bottom surface of this partition and inscribed in the peripheral wall of the box. A diaphragm-type buoyancy structure for submarine foundation work, which is constructed by fixing a diaphragm to the inner circumferential wall of the bottom of the box, injects air into the space within the box below the diaphragm so that the buoyancy generated by submersion under the water surface becomes equal to the weight of the box. The positions of the shaped steel lattice partitions are determined in advance by calculation and installed, and multiple pieces of this structure are assembled closely together as appropriate, towed and fixed on water to the set destination point, and the structure is A diaphragm type buoyancy structure characterized in that concrete is introduced through the shaped steel partition grid to make the diaphragm correspond to the uneven shape of the water bottom, and the structure is fixed in the water by filling fresh concrete into the submersible structure. Underwater foundation construction method by body.