JPH09328744A - Water drain method and structure of water drain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To join both of a horizontal drain material and a vertical drain material securely so as to improve the water drainage effect by placing the vertical drain material in the shape of reverse U character on a top face of the horizontal drain material provided on a water bottom and bringing its horizontal part into contact with a face of the horizontal drain material. SOLUTION: A horizontal plastic drain material 30 is spread across a predetermined interval on a lower filter 20 which is spread on the whole face of a water bottom 10 to be improved according to a plan. On the other hand, various shoes are attached to one end of a vertical plastic drain material 40 which is pulled out from a roll, the vertical drain material 40 is placed to the predetermined depth on one side of the horizontal drain material 30 by using a casing for placing, and the vertical drain material 40 which is exposed from the water bottom 10 is cut to the length which is almost equal to the depth of placing. Next, a shoe is attached to the other end part of the vertical drain material 40 which is exposed from the water bottom 10, and the vertical drain material 40 is placed in the shape of reverse U character astride the horizontal drain material 30 to bring a horizontal part 43 of the vertical drain material 40 into pressure-contact with a top face of the horizontal drain material 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater drainage method and a structure of an underwater drainage for draining and improving soft bottom soil.

[0002]

2. Description of the Related Art It is known to use a horizontal drain material made of plastic as a substitute for a sand mat which is difficult to obtain. As for this type of drain construction method, a method of placing a vertical drain material in advance and a method of placing it vertically after laying a horizontal drain material have been proposed.

[0003]

In the above-mentioned drain technique, it is difficult to secure a sufficient contact area by merely contacting the upper portion of one vertical drain member with the horizontal drain member. . Moreover, when a weight is applied to the subseabed, the subseabed is deformed in an uneven shape (swelling), and the vertical drain material and the horizontal drain material are easily separated from each other. If both drain materials are separated, the drainage performance will be significantly reduced. It is technically difficult to reliably bond both drain materials in water, and it is also difficult to confirm the bonding status of both drain materials from the outside, and there remains concern about the reliability of the drainage effect.

The present invention has been made in view of the above points, and an object thereof is an underwater drainage method capable of reliably joining a vertical drain material and a horizontal drain material and having a high reliability for drainage effect. And to provide a structure for an underwater drain.

[0005]

The invention according to claim 1 is
In a drain method in which the exposed portion of the vertical drain material cast on the bottom of the water and the horizontal drain material laid on the bottom of the water are brought into contact with each other, a continuous vertical drain material is reversed U on the upper surface of the horizontal drain material laid first. It is a drain method, which is characterized in that it is cast in a letter shape and the horizontal portion of the vertical drain member is brought into contact with the upper surface of the horizontal drain member. The invention according to claim 2 is the drain method according to claim 1, characterized in that a continuous vertical drain material is laid in an inverted U-shape across the horizontal drain material laid in advance. . The invention according to claim 3 is the drain method according to claim 1, characterized in that a continuous vertical drain material is pierced through the horizontal drain material laid in advance and is driven in an inverted U-shape. According to a fourth aspect of the present invention, in a structure of an underwater drain in which a vertical drain material cast on the bottom of the water and a horizontal drain material laid on the bottom of the water are in contact with each other, the upper surface of the horizontal drain material laid first by the vertical drain material. The structure of the underwater drain is characterized in that the horizontal portion of the vertical drain material is laid across the ground and is in contact with the upper surface of the horizontal drain material.

[0006]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<B> Laying process of horizontal drain material (FIG. 2) After laying the lower filter 20 on the entire surface of the water bottom 10 to be improved, a known horizontal drain made of plastic is provided on the lower filter 20 at a predetermined interval. The material 30 is laid. As the lower filter 20, a flexible net-like material that blocks the permeation of the bottom of the water 10 can be used.

<B> One-side driving process of the vertical drain material (FIG. 2) Various known shoes 42 are attached to one end of the plastic vertical drain material 40 pulled out from the roll 41, and one side of the horizontal drain material 30 has a predetermined depth. Drive up to. When the vertical drain 40 is driven, rigid casings (not shown) are used for driving. Any casing can be used as long as it can be placed without damaging the vertical drain member 40, and various known casings for placing can be used.

<C> Cutting of the horizontal drain material After the vertical drain material 40 has been driven to one side of the horizontal drain material 30 to a predetermined depth, the vertical drain material 40 exposed from the water bottom 10 has a length substantially equal to the driving depth. Disconnect. As a result, half of the vertical drain material 40 is left on the water bottom 10.

<D> Step of Driving Vertical Drain Material on One Side (FIGS. 3 and 4) The aforementioned shoe 42 is attached to the other end of the vertical drain material 40 exposed from the water bottom 10. Then, the other side of the vertical drain member 40 is driven into the other side of the horizontal drain member 30. At this time, it is important that the vertical drain member 40 is strung over the horizontal drain member 30 and is driven in an inverted U shape.
It should be noted that the vertical drain member 40 may be driven by using a well-known casing or by using a steel material having a B-shaped cross section that can protect only one surface of the vertical drain member 40. good. As a result, as shown in FIG. 4, the horizontal portion 43 of the vertical drain member 40 has no slack, and the lower surface of the horizontal portion 43 is pressed against the upper surface of the horizontal drain member 30.
The vertical drain member 40 is laid on the horizontal drain member 30 by straddling the vertical drain member 40 with the horizontal drain member 3.
While fixing 0, the water permeation area between the vertical drain member 40 and the horizontal drain member 30 is ensured, and the horizontal portion 43 of the vertical drain member 40 follows the horizontal drain member 40 when the horizontal drain member 30 changes with the bottom 10. Let both drain materials 3
This is to maintain the contact surface state of 0, 40.

<E> Loading (FIG. 4) After the casing is recovered, the entire surface of the water bottom 10 is covered with the upper filter 21, and various known weights 50 are placed on the upper filter 21. As the weight 50, it is possible to employ a layered pile of earth and sand or a bag in which various aggregates are packed.
The weight 50 is compacted by loading, and the pore water in the water bottom 10 rises through the vertical drain member 40 and is drained through the horizontal drain member 30 that is in contact with the horizontal portion 43 of the vertical drain member 40. Further, even when the water bottom bulges due to the loading of the weight 50, the horizontal portion 43 of the vertical drain member 40 follows the deformation of the horizontal drain member 30 and the contact surface state between the drain members 30 and 40 is maintained.

[0012]

Second Embodiment Although the above embodiment has been described with respect to the case where the vertical drain member 40 is driven while straddling one horizontal drain member 30, a plurality of horizontal drain members 3 are used.
You may straddle 0 and type in. Further, as shown in FIG. 5, the vertical drain member 40 may be driven in an inverted U-shape without penetrating the horizontal drain member 30 and penetrating the horizontal drain member 30. The same parts as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

[0013]

[Third Embodiment of the Invention] The case where the lower filter 20, the horizontal drain member 30, and the upper filter 21 are individually laid has been described above, but as shown in FIG. 6, the lower filter 20, the horizontal drain member 30, and the horizontal drain member 30, Upper filter 21
Alternatively, the vertical drain member 40 may be placed after laying the sheet-like material 60 integrally formed in advance at once. In addition, as shown in FIG. 7, the weight bag 5 is provided on the upper surface of the sheet-like object 60.
You may use what integrated 1.

[0014]

Since the present invention is as described above, the following effects can be obtained. <B> Since the vertical drain material is cast in an inverted U-shape, the horizontal portion of the vertical drain material can be brought into contact with the horizontal drain material in a state of pressure contact. Therefore, even if the horizontal drain material is deformed together with the submarine ground, it is possible to maintain a good contact surface condition that serves as a drainage path for both drain materials, and the reliability of the drain effect is enhanced. <B> As a method of arranging the vertical drain material in an inverted U shape, a method of placing a single body of the vertical drain material on both sides of the horizontal drain material and then binding the upper portion of the vertical drain material is considered. However, this method has the drawbacks that the binding work must be performed in water, and that it is difficult to bind without loosening. On the other hand, according to the present invention, since a single vertical drain member is placed without being divided, the vertical drain member can be placed without any underwater work and without slack. <C> By using a sheet-like material in which the upper and lower surfaces of the horizontal drain material are covered with filter material and a weight bag integrated with this, the number of processes can be reduced and the construction period can be shortened.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a driving configuration of a vertical drain material according to the present invention.

[Fig. 2] An explanatory view of a draining method in which a vertical drain material is placed in advance on one side of a horizontal drain material.

[Fig. 3] An explanatory diagram of a draining method in which a vertical drain material is placed on the other side of the horizontal drain material afterwards.

[Figure 4] Enlarged view of the horizontal part of the vertical drain material

FIG. 5 is a conceptual diagram showing another placement form of the vertical drain material.

FIG. 6 is a conceptual diagram showing another embodiment using a sheet-like material.

FIG. 7 is a conceptual diagram showing another embodiment in which a sheet-like material in which a weight bag is integrated is used.

[Explanation of symbols]

 10 ... Water bottom 20 ... Bottom filter 21 ... Top filter 30 ... Horizontal drain material 40 ... Vertical drain material 41 ... Roll 42 ... Shoe 43 ... Vertical drain material horizontal part 50 ... Weight 51 ... Weight bag 60 ... Sheet-like material

Claims (4)

[Claims] 1. A drain method in which an exposed portion of a vertical drain material cast on a bottom of a water is brought into contact with a horizontal drain material laid on the bottom of a water. A drain method, wherein the drain material is cast in an inverted U shape, and the horizontal portion of the vertical drain material is brought into contact with the upper surface of the horizontal drain material. 2. The drain method according to claim 1, wherein a continuous vertical drain material is laid in an inverted U shape so as to straddle the horizontal drain material laid in advance. 3. The drain method according to claim 1, wherein a continuous vertical drain material is pierced through the horizontal drain material laid in advance and the continuous vertical drain material is placed in an inverted U-shape. 4. In a structure of an underwater drain in which a vertical drain material cast on the bottom of the water and a horizontal drain material laid on the bottom of the water are in contact with each other, the vertical drain material extends over the upper surface of the horizontal drain material. The structure of the underwater drain is characterized in that the horizontal part of the vertical drain material is in contact with the upper surface of the horizontal drain material.