JPH0522768B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for horizontally burying a plurality of drain materials in the ground at different positions vertically to improve ultra-soft ground. be.

(Prior Art) When a pump dredger is used to dredge soft viscous soil deposited on the bottom of a seabed or the like and dump it into a landfill, ultra-soft ground is formed. There is no conventional method to improve such ultra-soft ground, such as allowing natural consolidation and then adding the next dredged soil, or after natural consolidation has developed a certain degree of bearing capacity, drain material is placed and then sand, etc. It was necessary to use a forced consolidation method using heavy weights, which required a long period of time for natural consolidation, and it took a long time to reach a state where conventional ground improvement methods could be implemented. In consideration of this point, drain material was buried horizontally in the soft ground,
A ground improvement method that sucks out water in soft ground through the drain material is being considered.

(Problem to be Solved by the Invention) However, in order to implement such a ground improvement method, it is necessary to horizontally bury drain material at a desired depth in the soft ground, but this is currently not possible. At present, no suitable burial method has been proposed.

An object of the present invention is to provide a method for horizontally burying drain materials that can easily lay a plurality of drain materials in soft ground at different positions up and down.

(Means for Solving the Problems) In order to achieve the above object, the method for horizontally burying drain material of the present invention includes loading a reel wound with drain material on board a ship, and feeding out the drain material under the bottom of the ship. A drain material burying vessel with a drain material burying guide protruding thereon is floated on soft ground, and the tip of the drain material fed out into the soft ground by the drain material burying guide is fixed to a fixing member. The method is characterized in that horizontal burying is performed while moving the drain material burying ship and drawing out the drain material from the drain material burying guide.

(Function) By doing this, the plurality of drain materials installed on reels on the drain material burying vessel can be
Since the drain material can be fed out by a drain material burying guide that protrudes downward from the bottom of the ship, the drain material can be easily horizontally buried at a desired depth by simply fixing the ends of the drain material and moving the drain material burying ship.

(Example) Examples of the present invention will be described in detail below with reference to the drawings. 2 to 5 show an example of the drain material burying vessel 1 used in this embodiment. This drain material burying ship 1 has a twin-copper type hull 2, and a float 3 made of styrene foam or the like is attached to the hull 2. A plurality of reels 4 are rotatably mounted on the upper surface of the hull 2 via brackets 5.

Each reel 4 has a drain material 6 made of nonwoven fabric, etc.
are each wound up. The drain material 6 has a rectangular flat shape, and its distal end 6A is closed, and a vacuum hose 7 is connected to its proximal end 6B via a connector 8. Hull 2
A drain material embedding guide 10 is rotatably supported at the bottom of the drain material embedding guide 10 with its upper end pivotally supported by a pivot 9. This drain material embedding guide 10 has a guide main body 11 made of channel material or the like with one side open and supported by a pivot 9 with the opening facing backward.
Each drain material 6 guided through the guide body 11 is turned around and fed out horizontally by guide rolls 12 attached to the guide body 11 at different positions in the vertical direction. That is, depending on the position of the guide roll 12, the drain material 6
The burial position in the vertical direction can be determined. Wires 1 are installed at the front and rear of the hull 2 to set the direction of the drain material buried guide 10.
3, 14 are attached, and these wires 13, 1
By adjusting the length of 4 using manual winches 15 and 16 on board, the hanging angle can be set. In addition, drain material embedding guide 10
When not in use, by loosening the wire 13 and winding up the wire 14, the drain material buried guide 10 can be stored at the bottom of the twin copper hull 2.

Next, a method for horizontally burying drain material according to this embodiment using such a drain material burying vessel 1 will be described with reference to FIG. 1. A drain material burying ship 1 having the structure as described above is floated on the soft ground 17.
Note that 18 is the water surface. In this state, one end of the rope 20 is connected via the ring 19 to the tip 6A of the drain material 6, which has been let out by each guide roll 12 of the drain material embedding guide 10 at different burial positions up and down. The other end is fixed to a fixing member 21 made of a single tube or the like. Further, a weight is placed on the rear part of the hull 2. In this state, the drain material burying vessel 1 is moved by pulling it in the direction of the arrow with the wire 22. As a result, each drain material 6 is paid out from the drain material embedding guide 10 while changing its burying position up and down, and is buried horizontally in the soft ground 17. It goes without saying that each wire 20 may be fixed to the fixing member 21 by changing its position up and down to match the height of the guide roll 12.

After burying each drain material 6 as shown in FIG.
A vacuum hose 7 is connected to the base end 6B of the drain material 6 via a connector 8, and a vacuum pump (not shown) is operated to vacuum the inside of each drain material 6. As a result, the water in the soft ground 17 is absorbed by each drain material 6, and the ground can be improved in a short period of several months.

By improving the ground in this way, the following effects can be obtained.

(b) By significantly lowering the water content ratio of clayey soil, the volume of sedimentary soil is reduced. As a result,
It will be possible to blow dredged soil into the landfill twice.

(b) In areas where drain materials are buried horizontally, the strength of the clay soil is greatly increased, making it possible to directly sow sand using a bulldozer during soil covering work, making the traditional netting method unnecessary.

(Effects of the Invention) As explained above, in the method for horizontally burying drain material according to the present invention, the drain material mounted on a reel on a drain material burying ship is moved by a drain material burying guide that protrudes downward from the bottom of the ship. Since the drain material can be fed out, the drain material can be easily horizontally buried at a desired depth by simply fixing the tip of the drain material and moving the drain material burying vessel.

[Brief explanation of drawings]

FIG. 1 is a side view showing an example of the implementation state of the method of the present invention, FIGS. 2 to 4 are a plan view, side view, and front view showing an example of the drain material burying vessel used in this example, FIG. 5 is a perspective view showing an example of a drain material. 1... Drain material buried ship, 2... Hull, 4...
Reel, 6...Drain material, 6A...Tip, 6B
... Base end, 7 ... Vacuuming hose, 9 ... Pivotal part, 10 ... Drain material buried guide, 11 ... Guide body, 12 ... Guide roll, 20 ... Wire, 21 ... Fixing member.

Claims (1)

[Claims] 1. A drain material burying vessel, which has a reel wound up with drain material mounted on the ship and a drain material burying guide protruding below the bottom of the ship for feeding out the drain material, is floated on soft ground, and the drain material is placed in the soft ground. The tip of the drain material fed out by the drain material burying guide is fixed to a fixing member, and horizontal burying is performed while the drain material burying vessel is moved in this state and the drain material is fed out from the drain material burying guide. A method for horizontally burying drain material.