JPS60203729A - Ground improving method - Google Patents

Abstract

PURPOSE:To scrape off a muddy water gelled substance adhered to a wall surface, by means of the discharge pressure of a curing material, by a method wherein a cavity, being full of muddy water, is filled with the curing material from the lower part of the cavity as the curing material is discharged in the direction of a cavity wall surface. CONSTITUTION:A guide pipe 12, provided at its forward end with a nozzle 13, is lowered in a cavity 1 being full of muddy water 11, and a curing material 15, such as cement milk, is discharged through the nozzle 13 as the guide pipe 12 is rotated. When, with this process, the guide pipe 12 is lifted, a gelled substance 16, adhered to a wall surface 1a of the cavity 1, is scraped off, the gelled substance is mixed in the muddy water 11. This enables the injected curing material 15 to be coagulated through reaction of the curing material to the muddy water 11 without forming a not substituted layer between the wall surface 1a and the curing material.

Description

[Detailed Description of the Invention] fIl), Technical Field of the Invention The present invention is directed to the construction of artificial ground, water-stop walls, etc. by excavating a cavity underground and filling and solidifying a solidifying material such as cement into the cavity. This article relates to ground improvement methods suitable for use in construction.

(b), Background of the technology When constructing artificial ground, a cavity is excavated underground and the hollow part is replaced with a ground improvement agent such as cement, resulting in a plate-shaped solid artificial ground underground. Construction methods have been proposed (JP-A-57-133918, JP-A-58-24020, JP-A-58-26115, JP-A-58-20819, etc.).

In addition, as one construction method for constructing artificial ground underground, the muddy water inside the cavity and cement are reacted and solidified in a cavity that has been excavated and filled with muddy water, thereby easily constructing artificial ground. There are known ways to do this.

(C), Prior Art and Problems Figure 5 is a schematic diagram showing a conventional ground improvement method, and Figure 6'j is a front view showing an artificial ground constructed by the conventional method.

Conventionally, in this type of construction method, as shown in Fig. 5, muddy water 11 is pumped up from a cavity 1 by a pump 2 and put into a mixer 3, cement is thrown into the mixer 3 to mix the cement and muddy water, and then A construction method has been used in which the mixture is returned to the cavity 1 via a tank 5, a pump 6, a tremie pipe 7, etc., and the cement is sequentially solidified from the bottom of the cavity. However, gelled material 16 from the muddy water that filled the cavity when the cavity was excavated is attached to the wall surface 1a of the cavity, and this gelled material remains without reacting with the cement even if the cavity is filled with cement. However, as shown in FIG. 6, the cement remains as an unsubstituted layer 9. However, artificial ground, etc., which is usually constructed by filling with cement, cannot be used to fill these cavities.・Since the trenches are constructed in a continuous manner in the structural direction of the soil units I and 10 filled with There were drawbacks such as leakage.

(d) 0 Purpose of the Invention In order to eliminate the above-mentioned drawbacks, the present invention provides a method for injecting a solidifying agent such as cement without creating an unsubstituted layer of the solidifying agent. The purpose is to provide a ground improvement method.

(e) Configuration of the invention 0, that is, the present invention is to fill a cavity which is not filled with muddy water with a solidifying material from below the cavity while discharging it toward the wall surface of the cavity at a predetermined pressure. It is constructed so that gelled muddy water adhering to the cavity wall is scraped off into the muddy water by discharge pressure.

(f) 0 Examples of the invention Examples of the present invention will be described below based on the drawings. will be explained in detail.

Figure 1 is a schematic diagram showing an example of the soil improvement method according to the present invention, Figure 2 is a diagram showing the results of a demonstration experiment of the soil improvement method according to the present invention, and Figure 3 is an experiment using the conventional method in the demonstration experiment. An enlarged view showing the results. FIG. 4 is an enlarged view showing the experimental results of the construction method based on the present invention in a demonstration experiment.

A solidification material such as cement is filled in the cavity 1 which has been excavated.
In order to construct the artificial ground ground unit 10 in the cavity 1 by reacting with mud and solidifying it, first, as shown in FIG.
1 and lower it into the filled cavity 1. Next, Guy F tube 1
2 is rotated in the direction of arrow A in FIG. 1, solidifying material 15 such as cement milk is discharged horizontally from nozzle 13. Then, the gelled material 16 adhering to the wall surface la of the cavity 1 is scraped off from the wall surface 1a by the discharge pressure of the solidifying material, and the muddy water 11
get mixed in. The gelled material 16 is originally a gelled and adhered component in the muddy water 11, so even if the gelled material 16 is mixed into the muddy water 11, the differences between the cement and the muddy water 11 will be reduced! Amanjot
This vfchi's evil scolding momo t= will never be ignored. Further, the discharge pressure of the cement from the nozzle 13 is not strong enough to excavate the wall surface 1a, but is weak enough to scrape off the gelled material 16, so it may not damage the shape of the already excavated cavity 1. No (normally, the physical strength of the gelled material 16 is overwhelmingly weaker than the strength of the wall surface 1a).

When the guide tube 12 is rotated in the direction A while discharging the cement and pulled upward in FIG.
is gradually scraped off from the lower part of the cavity 1 into which the solidifying material 15 is injected, and therefore the injected solidifying material 15 reacts with the muddy water 11 without creating any unformed V1 exchange layer 9 between it and the wall surface 1a. Then, it solidifies.

2 to 4 show the results of a demonstration experiment of the present invention using the corrugated pipe 17 as the cavity 1. A corrugated pipe 17 with a diameter of 2 m is used as a cavity 1, and muddy water 11 is filled in it. First, muddy water 11 and solidifying material 15 are injected and solidified using the conventional construction method shown in FIG.
As shown in the left half of the figure and FIG. 3, an unsubstituted layer 9 made of gelled material 16 with a thickness of T1=jO~20 mm is formed on the side surface, and further has a thickness of T2. -30~
A 50 mm unsubstituted layer 9 resulted. Next, when the solidified material 15 is reacted with the muddy water 11 ejected from the nozzle 13 according to the present invention, the unsubstituted layer 9 is formed as shown in the left half of FIG. 2 and the left half of FIG. Only a few pieces of unsubstituted layer 9 remained on the bottom part 17b, but no unsubstituted layer 9 was observed on the side part 17a corresponding to the wall surface 1a where the ground units 10 are actually connected to each other.

(g) 0 Effects of the Invention As explained above, according to the present invention, the solidifying material 15 such as cement I is discharged into the cavity 1 filled with muddy water 11 in the direction of the cavity wall surface 1a at a predetermined pressure. The structure is such that the cavity 1 is filled from below while the solidification material 15 is discharged, and the gelled material 16 of the muddy water 11 adhering to the cavity wall surface 1a is scraped off into the muddy water 11 by the discharge pressure of the solidification material 15. Almost no unsubstituted layer 9 of the solidified material 15 remains in the solidified ground unit 10, and even when the ground unit 10 is made continuous in the horizontal direction,
An unreplaced layer 9 as shown in FIG. 6 is not formed between the ground units 10, and accidents such as water puddles through the unreplaced layer 9 can be prevented. This makes it possible to provide a highly reliable ground improvement method.

Further, by discharging the solidifying material 15, the muddy water 11 is stirred, so the muddy water 11 in the cavity 1
The concentration of the solidifying material 15 is made uniform, and a homogeneous and good ground unit 10 can be constructed.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing an example of the soil improvement method according to the present invention, Figure 2 is a diagram showing the results of a demonstration experiment of the soil improvement method according to the present invention, and Figure 3 is an experiment using the conventional method in the demonstration experiment. An enlarged view showing the results, Figure 4 is an enlarged view showing the experimental results of the construction method based on the present invention in the demonstration experiment, Figure 5 is a schematic diagram showing the conventional ground improvement method, and Figure 6 is the construction using the conventional method. FIG. 1...Cavity 1a...Wall surface 10...Artificial ground (ground unit) 11...Muddy water 15 - Assimilation material 16...Gelified material Applicant Mitsui Construction Co., Ltd. N.I. Patent Attorney Phase 1) Shinji Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 (16) Procedural amendment (method) % formula %) 1 Indication of case 1988 patent application No. 19021 No. 2 Name of the invention Ground improvement method 3, Relationship to the 71n positive case Ryoji Machida Resident Iy [1752 Zushicho, Machida City, Tokyo Name]
Nino Sun Freeze Co., Ltd. Representative Motohiro Goto Yuuki 5 111) σ 6 Full text of the specification subject to amendment 7 Contents of the amendment Purification of the specification (no change in content)

Claims (1)

[Claims] In a ground improvement method for constructing artificial ground, water-stop walls, etc. by forming a cavity in the ground and filling the cavity with a solidification material and solidifying it, use muddy water: l? A solidifying material is discharged from below the cavity into the cavity at a predetermined pressure in the direction of the cavity wall, and the discharge pressure of the assimilating material transforms the gelled muddy water adhering to the cavity wall into muddy water. A ground improvement method that consists of scraping the inside of the ground.