JPS59179920A - Underwater structure - Google Patents

Abstract

PURPOSE:To easily construct and remove an underwater structure by a method in which a float is attached to one end of a cylinder made of a flexible film, the other end of the cylinder is fixed to the bottom under water, and the intermediate part of the cylinder is attached with an annular reinforcement. CONSTITUTION:Annular reinforcements 5 are attached at given intervals to a cylinder 1 made of a flexible film, and the cylinder 1 is folded into a bellows form and delivered to a site. A float 2 is attached to one end of the cylinder 1 to float it on the water surface and coupled with an anchor 7 settled on the outside of the setting position of the cylinder 1 through a rope 8. The folded cylinder 1 is pulled down in water and an annular anchor 3 is attached to the lower end of the cylinder 1 to fix it to the bottom under water. In this case, the lower end of the cylinder 1 is bent inwards along the surface of the bottom ground 4 under water. Sand is further charged into the cylinder 1 and its top is finished with pavement 9 as needed to form an underwater structure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an underwater structure suitable for constructing foundations for structures such as built islands, work yards, cofferdams, and breakwaters.

(Prior Art) Conventionally, the following methods have generally been used to construct underwater structures.

■Building an island using embankment, ■Construction method using steel sheet piles and steel pipe sheet piles,■
Construction of offshore platforms with membranes.

However, method (2) requires a legal slope of about 1:2 to 1:5, requires a large amount of earth and sand, and is laborious to construct. (With this method, reinforcement can only be done at the top, so when the water gets deeper, the cross section of the sheet pile becomes too large, which increases material and construction costs.)
After filling the membrane with sand, the hope is that water will be expelled and the water pressure from the outside will resist earth pressure and compact the sand. For this reason, the bottom is also surrounded by a membrane, making it impossible for piles to penetrate into the ground even if the inside is excavated.

(Object of the invention) This invention was made focusing on the above problems,
The purpose is to propose an underwater structure that has an extremely simple structure, is easy to construct and dismantle, is not affected by conditions such as ground and water depth, and can be used for foundation work of structures such as cane sinking and pile driving. There is something to do.

(Structure of the invention) The following will explain the embodiments shown in the drawings.

This underwater structure is made of a bendable membrane material, and has a cylindrical body 1 with both ends open as an outer shell. A float 2 is attached to one end of the float so that it floats on the water, and the other end has a slightly enlarged skirt-like opening, and an annular anchor 3 is attached to fix it to the bottom of the water. It is bent inside the cylindrical body l.

A plurality of annular reinforcing members 5 are attached at predetermined intervals in the direction of the outer circumferential hoop of the cylindrical body 1 arranged in this manner, and the inside thereof is filled with sand 6 to form a cylindrical mound underwater structure. There is. This structure is designed to improve installation stability by anchoring anchors 7 sunk in the outer water bottom with lobes 8. A top annular reinforcing member 5' is attached to the upper edge of the structure to maintain its shape. The paved surface 9 was used to improve workability.

The membrane material used in this invention is one having high tensile strength and foldability, such as rubberized cloth, synthetic fiber fabric, nonwoven fabric, and synthetic resin sheet laminate. As the annular reinforcing material, a material having high tensile strength such as steel, a polymer composite material such as FRP, or a synthetic fiber composite material is used.

However, the top annular reinforcing member 5' and the annular anchor 3 for fixing the lower end must be made of steel or the like having high rigidity to maintain their shape.

The structure has a cylindrical shape, but the diameter at the bottom is typically 1.0 to 1.5 times the diameter at the top. The annular reinforcing members are arranged at vertical intervals of 115 to 1/10 of the top diameter to resist the spreading pressure of the introduced sand.

(Function) This underwater structure has the above configuration. Its interior is filled with sand, and pressure (earth pressure) is generated in the cylindrical body as it tries to expand due to the sand. This pressure acts as a very large tensile force when the diameter is large, but since the annular reinforcement is attached in the direction of the hoop, even a relatively thin membrane material can withstand this tensile force. Since the bottom of the structure is open and directly under water, foundation work for the structure such as caisson sinking and pile driving can be carried out. In addition, the structure is simple, the slope is small, and only a relatively small amount of sand needs to be input and discharged.
Easy and quick construction, as it is necessary to eliminate inland water.
It can be removed if necessary. Furthermore, it does not need to be rooted in the ground, is not affected by the hardness or softness of the ground, unevenness, etc., and is not affected by water depth.

To construct this structure, annular reinforcing members 5 are attached at predetermined intervals to a cylindrical body 1 made of membrane material, folded into a bellows shape, and transported to the site. Here, a float 2 is attached to one end to float it on the water surface, and after locking and fixing 7 to an anchor 7 sunk outside the installation position, the folded cylindrical body 1 is pulled down into the water, and a ring-shaped anchor is attached to the lower end. Take it out and fix it on the bottom 4 of the water. At that time, bend the lower edge inward along the ground surface of the bottom 4 to prevent sand from flowing out and
To strengthen against sliding failure. In this state, sand is poured inside and the top is paved if necessary.

Removal can be easily carried out by reversing the above steps.

At this time, the cylindrical body and other members forming the outer shell can be used repeatedly.

Furthermore, if this structure is used to build a caisson island, etc., a large lateral pressure will be applied when it is submerged5, which is difficult to deal with with other construction methods, but with this structure, reinforcing materials are not required. It can be easily dealt with by strengthening it.

(Effects of the Invention) This invention is as shown in tile +, and this underwater structure brings about the following effects. σ) It has an extremely simple structure, is easy to construct and remove, and can be constructed at low cost regardless of conditions such as ground and water depth. 6) Able to perform foundation work for ladle structures such as sinking caissons and driving piles.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of an underwater structure according to an example. 1. Cylindrical body, 2. Float, 3. Annular anchor,
4. Water bottom, 5. Annular reinforcement, 5'. Top annular reinforcement, 6. Sand, 7. Anchor, 8. Rope, 9. Paved surface.

Claims (1)

[Claims] (1) A cylindrical body made of a bendable membrane material. A float is attached to one end of a cylindrical body with open ends to float it on the water. The other end is fixed to the bottom of the water, and the outer circumference of the cylindrical body is An underwater structure characterized in that annular reinforcing members are arranged at predetermined intervals in the direction of the hoop, and the cylindrical body is filled with earth and sand.