JPS5939570B2 - Improvement methods and equipment for soft ground - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for improving soft ground such as a sludge layer at the bottom of water, and an apparatus for implementing the construction method.

There is a well-known method of improving soft ground by injecting a chemical solution (ground improvement agent) while stirring the soft ground such as a sludge layer, and mixing the chemical solution into the sludge layer to harden the soft ground such as the sludge layer. .

By the way, in this type of ground improvement method, rotary stirring blades have traditionally been used to stir soft ground such as sludge layers.

If a rotary stirring blade is used, the device is complicated, there are many failures, and the stirring effect is not good enough considering the amount of power used.

In addition, a method for improving soft ground in which a pair of supporting members is cast using a work boat and the member for placing the soil improvement treatment agent is moved up and down using the supporting members as a guide is disclosed in, for example, Japanese Patent Application Laid-Open No. 52-12691.
It is described in Method 6.

However, in this construction method, the ground around the vertical plane is improved each time a pair of supporting members is cast, so in order to improve the ground over a wide area, the supporting members must be recast many times. It is sticky and troublesome.

Therefore, an object of the present invention is to provide a method for improving soft ground that can easily and efficiently improve soft ground over a relatively wide area, and an apparatus for directly implementing the method.

According to the method of the present invention, a floating body is towed to a work site, antibodies are lowered at the work site until it reaches the foundation under soft ground to prevent movement of the floating body, and a sieve suspended from the floating body by a guide pole is removed. It is inserted into soft ground and fixed to a floating body, and the floating body is moved up and down along the antibody, and the sieve suspended from the floating body is moved up and down to agitate the soft ground and spray the chemical solution from the chemical injection port provided on the sieve. The system is designed to improve soft ground by spraying it and mixing a chemical solution into the soft ground.

Further, according to the device of the present invention, a floating body that can float on the water surface, an antibody that hangs down from the floating body and can move relative to the floating body, and that reaches the foundation under the soft ground and prevents the floating body from moving;
A chemical liquid spout is suspended from a guide pole from a floating body, inserted into soft ground, and fixed to the floating body, and moves up and down by moving the floating body up and down along the antibody, stirring up soft ground such as a sludge layer. The sieve consists of an upper sieve part woven with a base mesh and a lower sieve part woven diagonally with respect to the upper sieve part. The outlet communicates with a chemical liquid pressure pump.

Therefore, the gravity of the floating body can be used to install and fix the antibody itself, and by moving the floating body up and down, the ground can be improved over a wide area where the sieve is located.

Next, by pulling up the antibody and moving the floating body, the area adjacent to the previously improved area can be improved one after another.

Therefore, it is possible to improve the ground over a wide area relatively easily.

In practicing the invention, the sieve may be moved up and down both by guide poles and by floating bodies.

As described above, since the stirring operation is performed by the vertical movement of the sieve, a considerable stirring effect can be obtained even with one vertical movement, and the combination with a floating body is effective in improving the sludge layer at the bottom of the water.

Hereinafter, examples in which the construction method of the present invention is implemented will be described with reference to the drawings.

Pile bodies 2.
... are hanging down, floating body 1 and pile body 2. ... are moved relative to each other in the vertical direction by, for example, a hydraulic mechanism and a rack and pinion mechanism, and when the floating body 1 is towed on the sea surface by a towboat, the pile body 2. ...
is pulled up, and during work, the pile bodies 2 are lowered until they penetrate the soft ground, for example, the sludge layer B, and reach the foundation, and the floating body 1 is fixed on the foundation to prevent its movement.

The floating body 1 has a large number of guide poles 3, nine in the illustrated example.
... are provided so as to hang down, and a sieve 4, the details of which will be described later, is attached to the bottom end of the sand.

During the work, the guide poles 3 are lowered, and the sieve 4 is lowered from the sea surface A shown in FIG. 1 to a suitable position in the sludge layer B shown in FIG. 2, and fixed at that position.

In order to raise and lower the sieve 4, for example, a tower (not shown) is built on the floating body 1 and the sieve 4 is raised and lowered using a winch.

Figures 3 and 4 show details of sieve 4;
is constructed by combining an upper sieve part 5 knitted in a basic pattern and a lower sieve part 6 knitted diagonally with respect to the upper sieve part 5.

In the illustrated example, the material constituting the sieve portion 5.6 is a hollow body with a diamond-shaped cross section, including a large number of blades T, . . . and a large number of chemical liquid jet ports 8. It is equipped with...

The chemical liquid passes through the guide poles 3 from a chemical liquid pressure pump (not shown) provided on the floating body 1, and then passes through the sieve parts 5 and 6.
It passes through the material constituting the chemical liquid and is injected from the chemical liquid jet port 8.

Next, the order of operations will be explained.

Pile body 2. ...and the sieve 4 is pulled up, and the floating body 1 is floated on the sea surface A and towed to the work site by a tugboat.

When you arrive at the work site, the first thing to do is to remove the pile body 2. ... to prevent the floating body 1 from moving by lowering it until it reaches the base under the sludge layer B,
In this state, the floating body 1 is pushed up above the sea surface A (FIG. 1), and then the sieve 4 is lowered to a suitable position in the sludge layer B and fixed to the floating body 1 at that position (FIG. 2).

In this state, the floating body 1 is moved to the pile body 2. ..., thereby moving the sieve 4 up and down and stirring the sludge layer B while opening the chemical solution spout 8 of the sieve 4. ...Spray more chemical liquid.

When the work is finished, the pile body 2. ...Then, the sieve 4 is pulled up, the floating body 1 is towed to the next area, and the same operation is performed.

As explained above, according to the construction method and device of the present invention,
Since a sieve is used to stir soft ground such as a sludge layer, it is possible to stir a wide range of soft ground at once, making it highly efficient and less likely to break down compared to using rotary stirring blades. The device can be provided at low cost.

Furthermore, in the present invention, the antibody is lowered until it reaches the base, and the floating body is fixed with the antibody while stirring the soft ground. Therefore, the ground improvement work can be carried out smoothly even in seas with high waves.

[Brief explanation of the drawing]

The drawings show the equipment used in the soft ground improvement method of the present invention. Figure 1 is a front view of the floating body being pushed up above the sea surface by lowering the antibody until it reaches the base, and Figure 2 is a front view of the floating body being pushed up above the sea surface using a sieve until it reaches the sludge layer. The front view in the lowered state, Figure 3 is the top view of the sieve,
Figure 4 is a detailed view of the sieve. 1...Floating body, 2...Pile body, 3...
...Guide pole, 4...Sieve, 5...
... Upper sieve part, 6... Lower sieve part, 7.
...Wing, 8...Medical liquid spout.

Claims (1)

[Claims] 1. In a method of improving soft ground by spraying a chemical solution while stirring the soft ground such as a sludge layer, a floating body is towed to a work site until it reaches the foundation under the soft ground at the work site. The antibody is lowered to prevent the floating body from moving, the sieve suspended from the floating body by a guide pole is inserted into the soft ground and fixed to the floating body, and the floating body is moved up and down along the antibody.
A sieve suspended from a floating body is moved up and down to agitate the soft ground, and a chemical solution is sprayed from a chemical injection port provided on the sieve.
A method for improving soft ground, which is characterized by improving soft ground by mixing a chemical solution into the soft ground. 2 In a device that improves soft ground by spraying a chemical solution while agitating the soft ground such as a sludge layer, the device is capable of moving relative to a floating body that can float on the water surface and is suspended from the floating body. An antibody that reaches the base under soft ground and prevents the floating body from moving, and an antibody that is suspended from the floating body by a guide pole, inserted into the soft ground, and fixed to the floating body, and allows the floating body to move up and down along the antibody. The sieve is equipped with a chemical liquid spout that moves up and down to stir soft ground such as a sludge layer. A device for improving soft ground, characterized in that the sieve is combined with a lower sieve portion, and a chemical liquid jet port provided in the sieve is connected to a chemical liquid pressure pump.