JPS58138818A - Vertical draining material and driving method thereof - Google Patents

Abstract

PURPOSE:To prevent the loading of a vertical draining material by confining specific flocculant in a continuous bag having small water permeability. CONSTITUTION:A flocculant powder 1 composed mainly of aluminum sulfate is confined in a continuous bag 2 made of a water-resistant and hardly water-permeable sheet with a large number of needle holes. The bags 2 are attached to both sides of a water guide plate 4 having grooves 3 on its upper and lower sides, and the outside is covered with a long cylinder 5 made of a filter material to form a vertical draining material A. When the vertical draining material A is used, the flocculant powder 1 in contact with void water in the ground is gradually dissolved in the void water to cause fine soil particles to flock by static electricity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for placing a particulate drain material that does not easily clog and is used for deep improvement of soft ground.

Currently, the pack drain method developed by Chiyoda Corporation is widely used for deep ground improvement. Two synthetic resin threads are woven into a mesh to form a tubular bag, and this bag is driven into soft ground. .

This method involves placing high-quality sand in a bag and forming a sand pile protected by a mesh-like bag in soft ground. The construction technology for this method has been established and its effectiveness has been proven, but recently it has become difficult to obtain high-quality sand and it has become expensive. For this reason, chemical materials that are of stable quality and can be stably obtained at low prices are expected.

Various chemical products have been developed and used, but there are some defects common to these particulate drain materials.
7. It has been pointed out that in the laboratory, it has very good suction and drainage capacity, but when it is actually used on soft ground, its suction and drainage capacity is not demonstrated, especially in a short period of time. is to decrease. Particular drains, which are chemical products, are all wrapped in a non-woven fabric or surface material with micron-sized pores, and absorb water from this surface, but the pore water in soft ground contains a lot of silt, clay, and colloids. It is known that these fine soil particles adhere to the surface of the surface material and cause clogging.

Another reason is that when pouring particulate drain material, it is good to protect the surrounding area with a casing, but in many cases, the tip is pulled and the surface of the drain material rubs against the ground, causing fine soil particles. It is presumed that this is because it gets stuck in the eyes.

Even when sand piles are used, experiments have shown that their ability to absorb and drain water is poor in the case of water containing fine soil particles.

The present invention aims to solve such problems.

Embodiments of the invention will be described in detail below with reference to the drawings.

[Example 1] A flocculant powder (1) mainly composed of sulfuric acid, which is known as a flocculation, precipitation, and filtration accelerator, was applied to a water-resistant plastic sheet with many needle holes as shown in Figure 1. It is enclosed in a continuous bag (2) made of a flexible and water-permeable sheet.

As shown in Figure 2, this continuous bag (2) is placed on both sides of a water guiding plate (4) having vertically continuous grooves (3), and the outside is shaped into a long cylindrical shape made of filter material such as unlined cloth. Cover with body (5) to form particulate drain material.

Usually, the size of a continuous bag is 1 to 3 (1), and the bag is partitioned in the middle by a method such as heat sealing, but it is roughly calculated as follows.

That is, one particulate drain is installed per one particulate drain, and the particulate drain is driven 10 m long and settled by 2 m. Then, 2R per partical drain, and Q2n per drain rate 1t2+? is drained.

If 1 ooppm is added to 1 muddy water, the calculated amount is 202 per 1 m. The actual amount to be used is determined by taking into consideration the effectiveness rate, etc.1゜[Example 2] As shown in Figure 3, high-density polyethylene mixed with 3 to 40% by weight of a polyacrylamide-based synthetic polymer flocculant is used. A monofilament (6) of 600 to 2,000 deniers is formed using the monofilament, and such a monofilament is woven into a mesh-like long cylindrical bag (7) with a weave size of 0.5 to 3 mm and a diameter of 12 cIr1. form. This long cylindrical bag is used in the pack drain construction method.

[Example 3] As shown in Figure 4, the weight ratio of the polymer flocculant was 3 to 40.
A nonwoven fabric (8) made of fibers of 10 to 200 denier is formed using polypropylene mixed with 15% of polypropylene. This kind of non-woven fabric has a thickness of 5 to 20J01 and a width of 10
The particulate drain material has a belt-like long body of about CR11.

In addition, in order to prevent temporary clogging until the added flocculant dissolves and takes effect, immediately before placing the particulate drain material, soak it in an aqueous solution with a relatively high concentration of flocculant. For example, a better effect can be obtained by providing a tank containing an aqueous solution of a flocculant immediately after winding up the particulate drain material in a casting machine, and casting through the tank.

Since the particulate drain material of the present invention is configured as described above, when it is driven into soft ground and comes into contact with pore water, the flocculant attached to the particulate drain material or mixed in the constituent materials will remain for a long period of time. It gradually dissolves in water, and the force of static electricity turns the fine soil particles around the particulate drain material into flocs. Even if flocculated soil particles adhere to the surrounding particulate drain material, the water permeability of the surface is reduced so that a 6-degree film is formed. It is never lost.

Currently, particulate drains, which are required to be effective for about 100 days, had extremely low suction and drainage capacity in about a week, and the idea of installing particulate drains again was being considered, and by 1 p.m. the building was being built without sufficient ground improvement. If an accident such as uneven subsidence occurs after a building has been constructed, it is of great significance that this simple method can be used to solve the problem.

In particular, if the particulate drain material is soaked in an aqueous coagulant solution before pouring, the surface of the drain material is protected by the highly viscous coagulant, which prevents the drain material from rubbing against the soil and causing clogging. After pouring, the flocculant aqueous solution is diluted by the pore water in the ground, and the immediate electrostatic force turns the soil particles around the particulate drain material into flocs, which is extremely convenient. .

The flocculants used in the present invention are not limited to the sulfuric acid band and polyacrylamide-based synthetic polymers used in the examples, but include soil that is negatively charged and suspended in pore water when made into an aqueous solution. Any flocculant can be used as long as it neutralizes the surface charge of the particles to make the particles microscopic, or crosslinks two particles to form large flocs. Currently, this kind of flocculant is manufactured by Dai-Kogyo Seiyaku Co., Ltd. [Hisera L-J Gayo] (known and widely used).

Generally, the construction period for soil improvement using Birch/F-Caldrene material is about 100 days, so it is rare that the flocculant used remains effective during this construction period. For this reason, the flocculant is water' at once. Dissolve 'CI, l: Drunk 63 Example 1 Muu.

This allows the liquid to gradually ooze out through small water holes, or mixes with the plastic materials that make up the material, allowing the ingredients to be extracted. The material and method for kneading the flocculant are not limited to the examples, but may be added to low-density polyethylene to form a film, or mixed to vinyl chloride to form a sheet. Alternatively, a surface material may be formed by providing water absorption holes in these films or sheets. In addition, methods such as forming it into particles using a glue or attaching it to a nonwoven fabric using a binder may be used.

The amount of coagulant used depends on the type of coagulant, but it is common to use -5°V per 1 m length of the particulate drain.

Note that the present invention is not limited to deep improvement of soft ground, but can also be widely used in cases such as placing a lobe-shaped drain material in sludge for dewatering.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a continuous bag containing a flocculant, and FIGS. 2, 3, and 4 are perspective views showing examples of particulate drain material. A...Particle drain material 9-■...Flocculant powder, 2...Continuous bag, 3...Groove,
4... Introduction plate, 5... Long cylindrical body, 6... Monofilament, 7... Long cylindrical bag, 8... Nonwoven fabric, 4
...Usual name N Patent applicant Kiyoshi Yamamoto

Claims (1)

[Claims] <1) By electrostatic action when made into an aqueous solution. A method of gradually and over a long period of time making it effective by enclosing a flocculant that flocs fine soil particles into a continuous bag that has water permeability but low water permeability, or by kneading it into plastic material. A particulate drain material characterized by being added over almost the entire length. C) The particulate drain material according to item (1), characterized in that a polyacrylamide-based synthetic polymer compound is used as a flocculant. (3) The particulate drain material according to items (1) and (2), characterized in that 1 to 501 coagulants are added per meter of length. (4) The feature is that the particulate drain materials described in paragraphs (1), (2), and (3) are soaked in an aqueous coagulant solution immediately before pouring and then poured into the ground. A method of placing a particulate drain phase.