JPS61207725A - Installing method for caisson - Google Patents

Abstract

PURPOSE:To install a caisson on a shallow mound, by a method wherein the caisson is lifted up by means of buoyant bodies so that the draft is decreased over the water depth of the mound, and after the caisson is positioned on the mound, the buoyant bodies are sunk. CONSTITUTION:2 buoyant bodies 12 are moved alongside both sides of a caisson 10, the buoyant bodies are gradually floated through drainage of sea water ballast to engage each of rods 13 with each of hooks 11 of the caisson 10. Through further drainage of the ballast, the caisson 10 is supported from both sides for lifting up, and drainage is stopped when the draft of the caisson 10 is decreased over the water depth of the mound 17. After the caisson 10 and the buoyant bodies 12 are so moved as to position right above the mound 17, the ballast is poured in the buoyant bodies 12 to gradually sink them, the caisson 10 is seated on the mound 17, and at the same time the buoyant bodies 12 are separated from the caisson 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for installing a caisson, and more particularly to a method for installing a caisson floating on the surface of water to a submerged mound shallower than its stuttering water.

Conventional technology and its problems When installing a caisson floating on the sea surface on an underwater mound, if the water depth of the mound is shallower than the caisson's swamp, it is impossible to move the caisson above the mound while it is floating on the sea surface. It is possible. For this reason, in the past, a crane ship was usually used to lift the caisson slightly above the mound and move it above the mound. However,
With this method, it is impossible to install a large caisson that exceeds the capacity of a crane, especially on a mound in shallow water.

An object of the present invention is to solve the above-mentioned problems and provide a caisson installation method that allows a large caisson to be installed on a shallow underwater mound.

Means for Solving the Problems The caisson installation method according to the present invention is a method in which a caisson floating on the water surface is installed on a submerged mound shallower than its stuttering water, and a floating body with adjustable ballast is installed on the caisson. The caisson is supported from both sides by the buoyant body by being disposed on both sides, and the engaging members on both sides of the caisson are engaged with the engaging members on the side of the buoyant body, so that the caisson's water depth is smaller than the water depth of the mound. , lifting the caisson by the buoyant body, moving the caisson and the buoyant body so that the caisson is located directly above the mound, and lowering the buoyant body so that the caisson lands on the mound. It includes.

The number of floating bodies placed on both sides of the caisson is arbitrary.

EXAMPLE An example of a caisson installed by the method of the invention and a buoyant body used to carry out the method of the invention is shown in FIGS. 1 and 4-6.

The caisson (10) is made of concrete, for example, and has a long box shape from front to back. At the bottom of both sides of the caisson (10),
A plurality of downward hooks (engaging members (11)) are each fixed in an embedded manner.

The buoyancy body (12) is made of steel, for example, and has a box shape that is long from front to back. A caisson (10
A plurality of horizontal rods (engaging members) (13) that engage the hooks (11) of ) from below are fixed via brackets (14). A fender (15) is attached to the lower part of this side surface except for the rod (13) and the upper part.

Furthermore, the buoyancy body (12) is equipped with a seawater ballast filling and drainage device, and ballast adjustment is possible using this.

Next, referring to Figures 1 to 3, the above caisson (1
An example of the installation method of 0), that is, the method of the present invention will be explained.

First, the above caisson (10) and two buoyant bodies (12)
While floating on the sea surface (L), move it to the vicinity of the seabed mound by appropriate means.

Note that the stanchion of the caisson (10) is greater than the water depth of the mound. Then, connect the two buoyant bodies (12) to the caissons (1
These buoyant bodies (12
) with seawater ballast, and the rod (13) connects to the hook (1
1) Submerge these so that they are slightly lower than (see Figure 1).

Next, two buoyant bodies (12) are placed alongside the caisson (10) on both sides, the seawater ballast is drained, and they are gradually brought to the surface. As a result, first, the rods (13) of each buoyant body (12) engage the hooks (11) of the caisson (10) from below, so that they do not come off due to shaking.
The upper part of each buoyant body (12) and the upper part of the caisson (10) are connected to pull each buoyant body (12) upward (
(See Figure 2). Then, by draining the seawater ballast from the two buoyant bodies (12) and floating them, the caisson (10) is supported from both sides and gradually lifted.

When all or most of the seawater ballast of the buoyant body (12) is drained, the water depth of the caisson (10) becomes smaller than the water depth of the mound (11), so the drainage is stopped and the caisson (10)
) are positioned directly above the mound (17) (see Figure 3).

Next, seawater ballast is poured into the two buoyant bodies (12) to gradually sink them, thereby allowing the caisson (10) to land on the mound (17).

Once the caisson (10) has landed on the bottom, each buoyant body (12)
After separating the upper part of the buoyant body (12) from the caisson (10), the buoyant body (12) is further lowered slightly, the rod (13) is removed from the hook (11), and the buoyant body (12) is attached to the caisson (10).
) on both sides. This results in one caisson (10)
After completing the installation of the caisson, the next caisson will be installed in the same way.

Effects of the Invention In the method according to the present invention, ballast-adjustable buoyant bodies are arranged on both sides of a caisson, and engaging members on both sides of the caisson are engaged with engaging members on the sides of the buoyant body to transform the caisson into a buoyant body. lifting the caisson with a buoyant body so that the caisson's water depth is less than the water depth of the mound; moving the caisson and the buoyant body so that the caisson is located directly above the mound; In addition, since it involves sinking the buoyant body and bringing the caisson to the bottom on the mound, it is possible to safely and easily move the caisson floating on the water surface to the bottom mound, which is shallower than the stagnant water, without using a crane ship. Can be installed.

Therefore, according to the present invention, it becomes possible to install a large caisson that exceeds the capacity of a crane on a shallow underwater mound.

[Brief explanation of the drawing]

Figures 1 to 3 are partially cutaway front views showing an example of the caisson installation method according to the present invention in the order of steps, Figure 4 is a plan view of Figure 2, and Figure 5 is a partial view of Figure 4. The enlarged plan view and FIG. 6 are cross-sectional views taken along the line X--X in FIG. (10)... Caisson, (11)... Hook (retaining member), (12)... Buoyant body, (13)... Rod (engaging member), (17)... Mound . Figure 1, ill yo N-to-〇

Claims (1)

[Claims] A method for installing a caisson floating on the water surface on a mound at the bottom of the water that is shallower than its stuttering water, comprising: buoyant bodies with adjustable ballasts arranged on both sides of the caisson;
The caisson is supported from both sides by the buoyant body by engaging the engaging members on both sides of the caisson with the engaging members on the side of the buoyant body. A method of installing a caisson, including lifting the caisson, moving the caisson and buoyant body so that the caisson is located directly above the mound, and lowering the buoyant body so that the caisson bottoms on the mound. .