JPS58189407A - Horizontal water draining method - Google Patents

Abstract

PURPOSE:To improve soft ground by a horizontal draining method without the use of sand in which recessions are provided on the sides of a horizontal long drain part connected with a vertical drain, water absorptive holes are drilled in the inside of the recessions, and they are fixed to each other while leaving the connecting ports of vertical drain. CONSTITUTION:In the improvement of the deep layers of soft ground by using vertical drains, e.g., back drain, etc., a long drain material 1 consisting of a flexible corrugated pipe with undulatory surface, made of polyethylene, etc., is used as a substitute for an expensive sand as a horizontal drain layer. Then, recessions 2 connecting in the longitudinal direction of one or two lines are formed on sides of the long drain materail 1, a large number of water absorptive holes 3 are provided in the inside faces of the recessions 2, and the portions other than the holes 12 receiving a connector 12 leading to the vertical drain are buried with an adhesive, etc. By this, horizontal water draining can be attained without good quality sand.

Description

Detailed Description of the Invention The present invention relates to a method for horizontally draining water discharged to the ground surface by a vertical drain when performing deep improvement of soft ground using a vertical drain such as a back drain, and a material used therefor. .

Conventionally, a sand mat made of high-quality sand with a thickness of about 5011 mm has been used to drain water discharged to the surface during deep layer improvement. However, these days it has become difficult and expensive to obtain materials with good water permeability.

There is a strong demand for the development of this alternative method.

The present invention aims to provide a horizontal drainage method that does not require sand in response to such social conditions. In general, vertical drains are installed at substantially the same intervals both vertically and horizontally, and the drain material is cut so as to protrude above the ground surface.

The present invention focuses on these points, and an embodiment thereof will be explained in detail below with reference to the drawings. As shown in Figure 1, a semi-hard plastic material such as polyethylene has a wavy surface and is therefore flexible. It consists of a corrugated vibrator with a sexual nature. A large number of water absorption holes (2) are provided on the inner surface of this recess. The recesses are for forming insertion holes (4) with a width of about 103 mm at approximately equal intervals.

Places other than the insertion hole (4) are filled with adhesive t51 or sealant. The installation interval of the insertion holes should be slightly longer than the installation distance fg4 (1-15 m) of the particulate drain. The cross-sectional shape of the elongated drainage material of this embodiment is generally circular with a concavity, but it may also be a flat cylindrical shape. Its size is normal.

The diameter is 3 to 20 cI11.

FIG. 2 shows another embodiment of the long drainage material. Thick threads of semi-hard plastic such as polyethylene or nylon are intertwined in a three-dimensional irregular manner, and the points of contact of the threads are fused to form a lock-like flat body.A flexible and durable strip of vinyl chloride etc. Place the lock-shaped flat body on top of the sheet +71, fold it in half with the sheet outside, and wrap both ends of the belt-shaped sheet between the flat bodies.If formed in this way, the flat body A recess (2) is formed in between, and at the back of the recess, the part without the sheet is left as a water absorption hole (5). Since the lock-like object is flexible, the long drainage material formed in this way is flexible as a whole.The size of the drainage material, the spacing of the insertion holes, etc. are determined according to the previous implementation. Same as the example.

The insertion hole in the embodiment described above is suitable for inserting a thin object, but is not suitable for inserting a cylindrical object such as a back drain. Therefore, as shown in FIG. 3, a connector (2) is prepared, which has an opening part (2) that is covered by a cylinder at one end and a thin insertion part (It) at the other end.

To implement the present invention, long drainage materials are laid along the protrusions and protrusions of the particulate drain materials arranged in a straight line, and then, as shown in Figure 4, the long drainage materials are laid along the protrusions and protrusions of the plate-shaped particulate drains. ) are all inserted one after another into the recess (2) through the insertion hole and connected. It is preferable to use adhesive/sealant around the bars in other rows to make them airtight.

As shown in FIG. 5, the protrusion $4) of the back drain is connected to the connector via ).

After forming a horizontal drainage channel, embankment is performed, and the loading of the embankment causes pore water in the soft ground to be drained upward from the particle drain, and the discharged water is passed through the water absorption holes of the long drainage material into a long length. It enters drainage materials and is discharged outside the ground.

Before embanking, 5 to 15 o
A thin sand mat having a thickness of 11 mm may be formed.

Since the present invention is configured in this way, the water sucked up by the particle drain is reliably transferred to the long drainage material and discharged. Therefore, the construction cost is low because the sand layer can be completely omitted (or even greatly reduced), and its social significance is extremely large.

In addition, since the horizontal drainage channel of the present invention connects the protruding part of the particle drain and the long drainage material while maintaining airtightness, one end of the long drainage material is closely inspected, and a vacuum pump or the like is used from the other end. By suctioning the ground, it is possible to promote the drainage of pore water in the ground. In this case, the loading of the embankment can also be reduced, so a significant rationalization of construction costs can be expected.

In addition, since the entire horizontal drainage channel has a flexible structure, it can follow irregularities in the ground and unevenness caused by ground subsidence8.

[Brief explanation of the drawing]

FIG. 11 and FIG. 2 are perspective views of a long drainage material. FIG. 3 is a perspective view of the connector, and FIGS. 4 and 5 are sectional views of the koji mold showing the construction status. l...long drainage material, 2...dent, 3...water absorption hole,
4... Insertion hole, 5... Adhesive, 6... Lock-shaped flat body. 7... Sheet, 8... Both hook ends of the sheet, 9... Outer edge. 10...Opening part, 11...Insertion part, 12...Connector, 13...Protrusion of plate-shaped particle drain! ,
14... Back drain protrusion.

Claims (1)

[Claims] ■ A long drainage material having flexibility, pressure resistance, and water permeability in the longitudinal direction, characterized by having a recess on the side surface and water absorption holes on the inner surface of the recess. ■ Inserting all the protrusions of the vertical drains scattered at approximately equal intervals on a substantially straight line on the soft ground into the recesses attached to the side surface of the long drainage material described in claim U). A method for forming horizontal drainage channels featuring: 6) A horizontal drainage method characterized by forming a horizontal drainage channel by the method described in claim 2, closing one end of a long drainage material, and promoting drainage by suctioning from the other end. .