JPS63151717A - Cloth cylinder and formation of pile therewith - Google Patents

Abstract

PURPOSE:To form a simple and high-quality pile of cloth cylinder. CONSTITUTION:A cloth cylinder 1 coated with a rubbery paint, having a closed tip, is penetrated into the ground, and a hydraulic slurry 4 containing a water-soluble high molecular compound is charged under pressure into the cylinder 1 from above to expand the cylinder 1 in order to form a hardened round column 6. The pile can thus be constructed without noise and vibration while unnecessitating the needs for treatment of waste sludge and waste water.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention provides a fabric cylindrical body suitable for constructing piles used in constructing the foundations of civil engineering buildings, and a method for constructing piles using the same. It is related to.

(Conventional technology and problems) Conventionally, when constructing structures on soft ground, the method of improving the ground is to directly inject solidifying or coagulating materials such as cement glue or water glass into the ground. , Cement injection method or chemical injection method in which the mixture is mixed and hardened, concrete is placed under pressure in a rubber bag, etc., and foundation piles are driven without direct contact with the ground to construct piles in soft ground (special methods). 1982-156620) and recently, a method of improving soft ground by pumping coal ash slurry as an injection material into a cylindrical cloth bag made of synthetic fibers (Kensetsu Gijutsu Shimbun January 16, 1988) ) have also been developed.

However, the method of directly injecting a hardening agent or aggregating agent into soft ground and hardening it uses the soft ground itself, which is a natural material, so its constituent elements, water content, etc. vary widely, and the hardening material A high degree of technical judgment is required in selecting the ground, and it is extremely difficult to uniformly improve soft ground over a wide area three-dimensionally.

In addition, in the method of driving piles using rubber bags, etc.,
A steel injection pipe with a length equal to or greater than the pile length is required, and when pouring material is being poured, the injection pipe must be pulled up while pouring.
The process is complicated and impractical, and since the concrete is pumped, it has poor fluidity or material separation resistance, so the cement paste and aggregate separate during pumping, and the separated aggregates form what is called a bridge. This caused a phenomenon called blocking, which caused the steel injection pipe to become clogged.

Furthermore, the method of pumping coal ash slurry as an injection material into a cloth bag, like the above method, requires an injection pipe as long as the tube length or longer, and the slurry is gradually forced into the cloth bag from the bottom while maintaining a predetermined pressure. The injection pipe must be pulled up while the process is being carried out, which is still a complicated process, and the hardened material formed is mainly composed of coal ash slurry, so it cannot be said to be of sufficiently high quality in terms of strength characteristics. Ta.

(Means for Solving the Problems) The present invention has been made to solve the drawbacks of the prior art, and its purpose is to provide a cylindrical fabric that can easily and reliably form a high-quality cured product. The present invention provides a simple and high-quality method for constructing piles.

That is, the present invention provides a fabric cylindrical body made of a flexible cylindrical body coated with a rubber paint on at least one of the front and back surfaces of the fabric, and having a closed tip, and at least one of the front and back surfaces of the fabric. After inserting a fabric cylindrical body made of a flexible cylindrical body coated with a rubber-based paint and having a closed end into the ground to a predetermined depth, water-soluble By adding a polymer compound and press-fitting Kubon hard slurry, the cylindrical body is expanded and expanded, and excess water from the hydraulic slurry is dehydrated through the fabric that makes up the cylindrical shape, forming a substantially cylindrical hardened body. This is a method for constructing a pile using a cylindrical fabric body.

The fabric cylindrical body of the present invention is coated with a rubber paint on at least one of its front and back surfaces to increase water permeation start pressure, and has a closed tip.

The fabric coated with rubber paint is made of commonly used fiber materials, such as natural fibers such as cotton and hemp, and synthetic fibers such as nylon, polyester, polypropylene, and polyethylene. High internal pressure (5-1
Sufficient tensile strength (s
o-1000Kff/-) is preferable.

The rubber-based paint to be coated on the fabric is polyurethane, polysulfide-based synthetic amorphous rubber, etc. After coating, when drying and curing, the fabric is completely coated with a predetermined pressure (1 = 10 Kp
A coating film (with a thickness of 2 to 311 cm
Any material that can form a surface of about J) is sufficient.

It is another aspect of the present invention to construct a pile as described below using the fabric tube described above. That is, the pile construction method of the present invention consists of a flexible cylindrical body coated on at least one surface of the front and back with a rubber paint, and a fabric cylindrical body with a closed end that is coated on at least one surface of the front and back surfaces, and is deposited to a predetermined depth in the ground. After insertion, a water-soluble polymer compound is added from the upper open end of the cylindrical body, and Kubon hard slurry is press-fitted to expand and expand the cylindrical body. This is a method for constructing nine piles using a cylindrical fabric body characterized by dehydrating surplus water and forming a substantially cylindrical hardened body.

The method for inserting the fabric tube of the present invention into the ground includes, for example,
As shown in Figure 1, an excavation hole with a predetermined diameter or less is prepared in advance,
The cylindrical body can be inserted into this, but if the ground is soft, it is also possible to grasp the tip of the cylindrical body with the tip of the shaft and push it directly into the ground. When an excavation hole is prepared in advance and the fabric cylindrical body is inserted, the diameter of the excavation hole is sufficient as long as the fabric cylindrical body can easily fit therein, and usually the outside diameter of the cylindrical body (10
An~40 cm) is sufficient. By inserting the fabric cylindrical body in this way, the surrounding ground is forcibly consolidated by the expansion pressure of the cylindrical body when it expands, and the ground can be improved.

In addition, the hydraulic slurry containing a water-soluble polymer compound to be injected into the fabric cylinder from the ground surface may be any slurry that can be press-fitted with a pump, and the hydraulic cement may be cement-based, gypsum-based, pozzolan-based, or slag-based slurry. The system and other materials can be used alone or in combination, and when a water-soluble polymer compound is added, water retention, fluidity,
Cement-based mortar and concrete are preferred from the viewpoint of strength characteristics.

Further, examples of the water-soluble polymer compound to be added to the hydraulic slurry include methylcellulose, droxyethylcellulose, polyvinyl alcohol, and methylcellulose is particularly desirable. For example, in the case of cement-based mortar, the amount added to the hydraulic slurry is preferably about 0.1 to 0.3 of the weight of cement.

Next, as shown in Fig. 1 (B), the method of injecting the hydraulic slurry containing the water-soluble polymer compound into the inside of the fabric cylindrical body is to press the pump into the cylindrical body from the upper open end. However, this method is the simplest, quickest, and most economical.

In this way, by press-fitting the hydraulic slurry, the cylindrical body expands and pressure is applied to the cylindrical body, allowing excess water in the hydraulic slurry to be dehydrated through the fabric that constitutes the cylindrical body. , it is possible to form a substantially cylindrical shape (which may have some unevenness) as shown in FIG. 1(C).

Note that the injection pressure at this time depends on the ground conditions and the strength of the fabric, but is preferably about 5 to 15 to 9/-.

(Effect of the invention) The present invention has the following advantages.

■ Since a fabric tube that can be expanded by the injection pressure of hydraulic slurry is used, the drilling hole for inserting the fabric tube only needs to be less than half the outer diameter of the tube, and can be constructed using a small construction machine. is possible and economical.

■ Piles can be created through the following process by injecting a hydraulic slurry containing a water-soluble polymer compound into a fabric cylinder coated with a rubber paint.

1) Due to the clogging effect of the rubber coating film during the injection process (the coating seals the eyes of the fabric), and the synergistic effect of the water retention properties of the water-soluble polymer compound, dehydration of the hydraulic slurry is suppressed. In addition, material separation is eliminated due to the thickening effect of the water-soluble polymer compound, so that the cylindrical body can expand and expand almost uniformly over its entire length without being blocked midway.

II) Dehydration process In the final process of expansion and expansion, after the pressure is sufficiently transmitted to the tip, the high pressure acting on the inside of the uniformly expanded fabric causes the eyes of the rubber coating film to open due to the stretching of the fabric.゛The hydraulic slurry is quickly dehydrated, and as a result, high quality piles can be created〇■ The hydraulic slurry containing a water-soluble polymer compound is injected into the inside of the fabric cylinder. Therefore, a high quality hardened body can be obtained without the hydraulic slurry coming into direct contact with the ground.

■ Kubon hard slurry is made by adding a water-soluble polymer compound.
The construction is simple, quick, and economical because it is carried out by press-fitting the fabric tube from the upper open end of the fabric tube on the ground surface.

■ During construction, there is no noise or vibration, and there is no need to treat sludge or drainage, and the construction can be carried out without any pollution.

(Example) Hereinafter, the present invention will be explained in detail with reference to Examples.

Examples and Comparative Examples 1 to 3 As shown in Figure 1 (4), inner diameter 80IIJ + 1 length s
,oo.

A dragon drill hole is created in the ground, and an outer diameter of 150 mm is placed inside this drill hole.
wm5 Fabric with a length of 5,300 m (tensile strength 200
A cylindrical body coated with a rubber paint (polysulfide sealing material manufactured by Yokohama Rubber ■, product name: Hamatite dissolved in toluene at a ratio of 1:1) was made of a cylindrical body with a length of 5,000 mx. It was inserted using a steel rod. Next, as shown in Figure 50), tie the injection hose connected to the mortar injection pump to the open end of the upper part of the fabric cylinder, and set the cement/sand weight ratio to 0.5 and the water/cement weight ratio to 0. Methylcell P-su [Metrose 90SH-aoooo (manufactured by Shin-Etsu Chemical hereinafter MC) was added to the usual mortar.
)] was added in an amount of 0.2% by weight of the cement, stirred for about 2 minutes, and then injected into the cylindrical body using a pump.

In order to measure the pressure distribution inside the fabric tube during injection, a total of five pressure sensors were installed on the steel rod used to insert the tube. The pressure sensor is located at 50 m from the ground surface.
It was placed near the central axis of the cylindrical body at a position of 0.15G0.2500.3500.4500U.

Furthermore, a pressure sensor was placed in the middle of the injection hose to measure the pressure at the source of injection by the mortar pump.

After the injection started, the injection source pressure hardly increased until the inside of the cylinder was filled with mortar, but after it was filled,
As the cylindrical body expands and expands and its diameter increases, the injection source pressure of the pump begins to rise, and when this pressure reaches 1 OKff/cd, the pump can be stopped to complete the injection. (1st (
C) See figure) For comparison, a mortar coated with hamatite and without MCt added (Comparative Example 1)
) Same as in the example, using mortar without coating with hamartite and adding MC (Comparative Example 2) and mortar without coating with hamartite and without adding MC (Comparative Example 3) The pile was created using a method.

The pressure distribution inside the cylindrical body when the pump was stopped was measured, and the results are shown in FIG.

As a result of excavating and inspecting the piles manufactured in the example and comparative example at a later date, it was found that the piles according to the example had an almost completely hardened cylindrical body, and the outer diameter was approximately 1651J over the entire length.
It was before and after. On the other hand, in the case of Comparative Example 3, the upper end expanded and expanded to an outer diameter of 165 wt, but the outer diameter gradually became smaller at deeper depths. 2000m from the ground surface due to poor construction.
At depths greater than 5, the outer diameter was about 80u, which is about the same as the diameter of the hole excavation. Figure 3 shows the external appearance of these four excavated and quantified bodies.

[Brief explanation of the drawing]

Fig. 1 shows each step of the present invention; firstly, Fig.
(B) Figure 1 is a partially cutaway cross-sectional view of hydraulic slurry being injected from the open end of the ground surface of the fabric tube using an injection hose. Figure 1 (C) is a partially cutaway view of the fabric tube being expanded and expanded in the ground. and dehydration,
It is a partially cutaway sectional view of a cylindrical hardened body (pile) that has been solidified and completed. Figure 2 is a graph showing the pressure distribution state when the pump is stopped (pump pressure 1o Kgf/d) in the examples and comparative examples, and Figure 3 is a schematic diagram of the appearance of the cured bodies in the examples and comparative examples. The third figure shows the hardened body (pile) of Example, the third figure shows the hardened body of Comparative Example 1, and the third (C) figure shows the hardened body of Comparative Example 1.
The figure shows the appearance of the cured product of Comparative Example 2, and the third CD) figure shows the appearance of the cured product of Comparative Example 3. 1 is a cylindrical body made of fabric 2 is a drilling hole, and the upper open end 4 of the cylindrical body made of fabric is a material into which a water-soluble polymer compound is added, 9 hard slurry & is an injection hose, and a hardened body of hydraulic slurry ( Pile) Patent applicant Asahi Kasei Industries, Ltd. Figure 1 Figure 2 r

Claims (2)

[Claims] (1) A cylindrical fabric body that is made of a flexible cylindrical body coated with rubber paint on at least one of the front and back sides of the fabric, and whose tip is closed. (2) After inserting a fabric cylindrical body, which is made of a flexible cylindrical body coated with rubber paint on at least one of the front and back sides of the fabric and whose tip is closed, to a predetermined depth in the ground, By press-fitting the hydraulic slurry containing a water-soluble polymer compound into the upper open end of the cylindrical body, the cylindrical body is expanded and expanded, and excess water from the hydraulic slurry is dehydrated through the fabric that makes up the cylindrical body. A method for constructing a pile using a cylindrical fabric body characterized by forming a substantially cylindrical hardened body.