JP3150484B2 - Drain material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drain material used for ground improvement.

[0002]

2. Description of the Related Art It is known that loose saturated sand liquefied by an earthquake or the like causes serious damage. To prevent the liquefaction of the ground, compaction of sand ground or crushed stone is required. The construction method of crushed stone columns, which creates columns in the ground, is effective. However, each of these methods requires a large machine, is expensive in construction, and cannot avoid the occurrence of large vibrations. Therefore, it cannot be adopted depending on the surrounding environment.

[0003] In view of the above, adoption of a grid drain method or a drain pipe method, which can be carried out with a relatively lightweight machine, is considered. The grid drain method is to install a large-section drain board that enlarges the inner section of the paper drain into the ground, and the drain pipe method is to open a large number of through holes in the wall surface and drive a water-permeable pipe into the ground, In each case, excess pore water generated during an earthquake is introduced into a pipe or a water passage formed on a board, and the excess pore water pressure is quickly dissipated to prevent liquefaction of the ground.

[0004] Comparing the grid drain method and the drain pipe method, the former has a smaller inner cross section than the latter, so that the number of castings per unit area increases. However, the drain board can be wound and transported.
(5) allows efficient driving into the ground.

[0005] The casting machine (5) is provided with a casing (5) on a machine base (51).
2) A driving device (53) for driving the casing (52) into the ground and a drain board winding drum (1a) are provided (FIG. 7A).

The drain board (1) drawn from the drum (1a)
0) is inserted into the casing (52) from the upper end thereof to project from the lower end, and the anchor (2) is attached to the projected end. In this state, the casing (52) is driven into the ground (FIG. 7B).

When the lower end of the casing (52) reaches a predetermined depth, the casing (52) is pulled up. Drain board (10)
Stays underground due to the pulling resistance of the anchor (2) at the lower end, and only the casing (52) is pulled up (FIG. 7C). The drain board (10) is cut from the ground surface so as to protrude from the ground surface by about 10 to 20 cm, and the drain board (10) is sequentially placed on the ground by the same procedure as described above.

On the other hand, the drain pipe is housed in a casing in the same manner as described above, but is cut into a predetermined length (4.5 m is a standard length for transportation) because it cannot be wound. And carry it to the construction site. In addition, in the drain pipe method for liquefaction countermeasures of the ground, it may be necessary to drive in a depth of about 20 m. In this case, a drain pipe having a unit length must be connected, and the work efficiency is extremely poor. was there. The present invention discloses a drain material that can be wound and continuously fed out, and yet can be driven in a pipe state.

[0009]

The drain material of the present invention is formed entirely or partially of a shape memory material, is a flat body at normal temperature, has a pipe shape when heated, and has a wall having water permeability. .

[0010]

[Operation and Effect] The drain material (1) is a flat body at room temperature, so it can be wound and transported, and the drain material (1) drawn from the winding drum is transferred from the upper end to the casing (52) of the casting machine. At this time, heat is applied to the drain material to return the shape memory material to the memorized shape, the drain material is expanded into a pipe shape, and the pipe-shaped drain material (1) can be driven into the ground. By driving the pipe-shaped drain material (1) into the ground, excess pore water generated during an earthquake can be made to penetrate into the pipe, and the excess pore water pressure can be quickly dissipated to prevent liquefaction of the ground.

The drain material (1) cast on the ground has a pipe shape, has a larger inner space section than the drain board, and requires less number of pieces per unit area than the drain board. Since the time required for placing the drain material of the present invention and the conventional drain board per one piece is the same, the construction method using the drain material of the present invention is more efficient because only a small number of pieces need to be placed. improves.

[0012]

FIG. 1 shows a drain material (1) constituted by covering a drain material body (4) entirely formed of a shape memory resin with a water-permeable sheet (3). The shape memory resin has a different composition depending on the maker, and polynorbornene rubber, styrene-butadiene copolymer, trans-1.4-polyisoprene, or the like is used. A large number of through holes (41) are formed in the drain body (4) in a uniform distribution.

The drain material main body (4) is formed into a pipe shape at a shape memory temperature according to the composition of the shape memory resin, and then formed into a flat body by pressing at a temperature lower than the shape memory temperature. The water permeable sheet (3) of the embodiment is formed in a long bag shape by a nonwoven fabric made of synthetic resin fibers, and accommodates the drain material main body (4).

In the driving machine for driving the drain material (1) of the present invention, a heating device (6) is attached to the upper part of the casing of the conventional driving machine shown in FIG. 7 as shown in FIG. The heating device (6) of the embodiment is a hot air generating device, and a through hole (54) for blowing hot air is opened in the wall surface of the casing (52).

However, the drain material (1) is a flat body at room temperature, so that it can be rolled and transported as it is long. Also, the drain material (1) drawn from the winding drum (1a) is inserted into the casing (52) of the driving machine (5) from the upper end, and at this time, the drain material (1)
Then, the pipe-shaped drain material is blown into the ground while the pipe-shaped drain material is housed in the casing (52), and then only the casing (52) is pulled up to cast the pipe-shaped drain material.

[0016] Since the wound drain material (1) can be continuously fed, it is not necessary to join the wound drain material even in the case of deep casting.
Construction efficiency can be greatly improved compared to the conventional drain pipe method. Excessive pore water generated at the time of the earthquake due to the injection of the pipe-shaped drain material is allowed to penetrate into the pipe through the permeable sheet (2) and the through-hole (41) of the drain material, and the excess pore water pressure is quickly dissipated to dissipate the ground. Liquefaction can be prevented.

The drain material (1) cast on the ground has a pipe shape, has a larger inner space section than the drain board, and requires less number of pieces per unit area than the drain board. Since the time required for placing the drain material of the present invention and the conventional drain board per one piece is the same, the construction method using the drain material of the present invention is more efficient because only a small number of pieces need to be placed. improves.

FIGS. 3 and 4 show a drain material (1) that expands into a square pipe shape when heated, and a bag-shaped water-permeable sheet (3) is placed on a drain material body (4) in the same manner as in FIG. Coated. The corner portion (42) of the drain material body (4) to be expanded into a square pipe shape is formed of shape memory resin over the entire length, and the other wall (43) is formed of a simple synthetic resin (12). And
A number of through holes (41) have been opened.

The above-mentioned drain material main body (4) is formed into a square pipe shape at a shape memory temperature according to the composition of the shape memory resin.
The corner portion (42) is pressed into a flat body below the shape memory temperature. Although the shape memory resin is expensive, the square pipe-shaped drain material (1) uses a shape memory resin partially, so that the cost can be reduced.

In practicing the present invention, the diameter of the through-hole (41) formed in the drain material is set to an extremely small diameter, for example, about 0.075 mm, which is the minimum particle size defined as sand particles, and a number of such small holes are opened. Then, the water-permeable sheet can be omitted. In addition, if the drain material itself is formed of an open-cell foam and water permeability is imparted to the entire wall surface of the drain material, it is possible to save the trouble of opening a special through hole in the wall surface of the drain material.

As long as the condition that the drain material can be wound at room temperature is satisfied, a shape memory alloy can be used instead of the shape memory resin. The present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a drain material of the present invention.

FIG. 2 is a perspective view showing a state where the drain material is inflated.

FIG. 3 is a perspective view showing a part of a drain material according to another embodiment.

FIG. 4 is a perspective view showing a state where the drain material is inflated.

FIG. 5 is a sectional view of an upper portion of a casing of the driving machine.

FIG. 6 is a sectional view taken along line AA of FIG.

FIG. 7 is an explanatory diagram of a driving procedure.

[Explanation of symbols]

 (1) Drain material (3) Permeable sheet (4) Drain material body (41) Through hole

Claims (1)

(57) [Claims] 1. A drain material formed entirely or partially of a shape memory material, which is flat at room temperature but expands in a pipe shape when heated, and has water-permeable walls.