JP2002089164A - Pit forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pit forming method which can reduce the excavated depth of a pit relative to the depth in a conventional method, and can cut off water in spite of smaller usage of a harder such as concrete. SOLUTION: According to the pit forming method, after excavating the ground in the vertical direction, the hardener is injected from an injecting means (4) to the vicinity of a lower end of a longitudinal pipe (5) having an auger (1) arranged therein. The tip of the auger is protruded downward from a lower end of the longitudinal pipe (5). Then, the hardener is agitated by rotating the auger (1) by means of a spiral blade (3) attached to the periphery of the auger, and the hardener is cured with the auger (1) remaining in the longitudinal pipe (5). Then, the lower end of the longitudinal pipe (5) is blocked with a cut-off mass (7) which is the cured hardener, and thereafter the auger (1) is pulled out of the longitudinal pipe (5).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a vertical hole by stopping water at a lower end of a vertical pipe embedded in a vertical direction. Specifically, in plumbing works such as water supply and sewage, communication, gas, etc., it is used for a construction method for forming a vertical hole in a place where a digging work requiring a large space cannot be performed due to circumstances such as the surrounding environment and traffic. Also, the vertical hole,
It is sometimes used as a tank for storing rainwater.

[0002]

2. Description of the Related Art As a conventional method of forming a vertical hole in a ground requiring water stoppage, a method is known in which a vertical hole is dug, an auger in a vertical pipe is pulled out, and underwater concrete is poured into the vertical pipe.

However, in this method, earth and sand flows into the vertical pipe due to a negative pressure or the like generated when the auger is pulled out, and it is impossible to grasp the amount of earth and sand flowing in. Therefore, a vertical hole having a desired depth is obtained. This required digging much deeper than desired, which was uneconomical. In addition, since the water block is filled in the vertical pipe, the water pressure that is going to enter the vertical pipe must be received by the frictional force between the water block and the vertical pipe, and the dead weight of the water block. No.
Therefore, it is necessary to throw in a large amount of concrete to enlarge the water stopping mass, which is uneconomical.

[0004]

SUMMARY OF THE INVENTION The inventions according to claims 1 to 4 of the present invention have been developed in consideration of the above-mentioned circumstances, and a common object thereof is that the digging depth is smaller than in the prior art. Moreover, it is an object of the present invention to provide a vertical hole forming method capable of stopping water while reducing the amount of a solidifying material such as concrete.

Another object of the present invention is to provide a vertical hole forming method capable of easily performing construction work.

[0006]

According to the first aspect of the present invention,
After excavation in the vertical direction, the solidified material is injected from the injection means near the lower end of the vertical pipe having the auger inside, and the solidified material is rotated by the spiral blade whose tip end of the auger protrudes downward from the lower end of the vertical pipe. The solidification material is hardened while the auger is in the vertical pipe, and the lower end of the vertical pipe is closed with a water-block that has hardened the solidified material, and then the auger is pulled out of the vertical pipe.

[0007] The "vertical direction" here does not have a strict meaning. The “solidifying material” includes a cement type, a chemical type (urethane type, water-absorbing fiber type, etc.), a water glass type, and the like for the purpose of filling, and is required to be cured in a relatively short time. In addition, the reason for setting the injection point of the solidified material as `` near the lower end of the vertical pipe '' is that even if it is slightly above the lower end, the lower side of the lower end of the vertical pipe is stirred with a spiral blade, so that the vertical pipe is This is because the solidified material is stirred directly below.

The direction of rotation of the auger when stirring the solidified material is not particularly limited. When the solidified material rotates in the same direction as the excavation direction, the solidified material tends to rise on the spiral blade against the gravity. Therefore, the rotation speed is set to such an extent that the solidified material does not rise. In addition, if rotated in the direction opposite to the excavation direction, the solidified material will tend to move in the direction pressed against the bottom of the vertical hole, so the amount of solidified material that hardens while remaining on the spiral blade decreases, and the solidified material hardens This makes it easy to separate the portion that becomes the water-blocking mass from the portion where the solidified material placed on the spiral blade hardens, thereby shortening the stirring time. At the same time as the solidified material is injected, the solidified material and the soil are mixed and stirred by the spiral blade. At that time, it is preferable to gradually rotate the auger while pouring, and stop the raising after the pouring.
The auger may be raised after injecting a predetermined amount, but depending on the soil properties, there is a risk that the solidified material may diffuse into the surroundings or the ground may collapse when the auger is raised.

When the solidified material is hardened, it is desirable that the auger is raised at a position slightly higher than that at the time of injection or at the same height as the lower end of the vertical pipe or slightly above. To close the lower end of the vertical pipe with a block of water, the tip of the auger must be at least as high as the lower end of the vertical pipe, and if it is pulled too high, a large amount of solidified material will be used. Because it is uneconomical. If the raising position of the auger is below the lower end of the vertical pipe, there is a risk that earth and sand without solidified material may flow into the vertical pipe. In this case, incomplete water stoppage occurs.

When the auger is pulled out from the vertical pipe, the water block may not be completely cured, and the degree of the curing is
It suffices that the water stop lump does not enter the vertical pipe with the withdrawal. During the hardening of the solidified material, the auger may be stopped or may continue to rotate. If the auger has not been pulled out before the solidified material has completely cured, the auger will be integrated with the still water mass, so it is necessary to determine the timing of the withdrawal, but if it continues to rotate Work is easier because it is not necessary.

The term "injecting means" means all means capable of injecting the solidifying agent near the lower end of the vertical pipe with the auger inside the vertical pipe. Specifically, the injection means may be an injection pipe inserted along the outer circumference of the vertical pipe as in the invention of claim 2, or may be vertically penetrated as in the invention of claim 3. The rotation shaft of the auger having the inflow path described above may be used.

[0012] The auger may be one in which spiral blades are merely continuous outside the rotation shaft. In order to facilitate the insertion of the injection pipe, it is desirable that the ground around the buried vertical pipe is loose, and the auger has a spiral blade outside the rotation shaft as in the invention according to claim 4. In addition, a crushed material that rotates at a high speed about the central axis may be provided at the tip of the rotating shaft, and the ground may be hit at the tip of the crushed material. This is because the impact when the ground is hit with the crushed body rotating at high speed is transmitted to the vicinity of the hit location, and the ground is loosened.

The crushed material may be any one having a strength that does not break even when the ground is hit, and as an abstract example, a crushed body, a body having flexibility, or a continuous body in a chain shape And specific examples include a metal rod, a wire rope, and a chain.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a first embodiment of a vertical hole forming method according to the present invention is a general one for an auger 1.
That is, a spiral blade 3 continuous outside the rotary shaft 2 is used, and an injection pipe is used as the solidifying material injection means 4. In addition,
As an example of the solidifying material, there is a rapid setting mortar cement that sets in about 10 minutes to 1 hour.

As a specific procedure of the first embodiment, first, the vertical pipe 5 and the auger 1 are both hung down while rotating the auger 1 whose tip protrudes from the lower end of the vertical pipe 5 to a desired depth. Excavate. Since the soil is soft enough to stop water, below the vertical pipe 5, the ground collapses and the diameter of the vertical hole 6 becomes wider than the vertical pipe 5 to form a cavity, or due to the influence of auger drilling , It becomes more loose (not hard) than the ground. Next, the injection pipe 4 is press-fitted along the outer periphery of the vertical pipe 5, and the tip of the injection pipe 4 is inserted slightly below the lower end of the vertical pipe 5. FIG.
As shown in (a), the auger 1 is rotated in the direction opposite to the excavation direction while the solidified material is injected from the injection pipe 4, and the solidified material is stirred at the tip of the spiral blade 3. Since the injected material flows toward the center of the auger 1 having a small resistance, it hardly diffuses into the surrounding ground. After the stirring, the auger 1 is slowly pulled up while rotating in the reverse direction, and the tip of the auger 1 is set at the same height as or slightly higher than the lower end of the vertical pipe 5 as shown in FIG. The reverse rotation is continued at the same height until the curing, and the cured water-block 7 and the auger 1 are prevented from being integrated. After the water blocking mass 7 is formed, the auger 1 is pulled out from the vertical pipe 5, and the vertical hole 6 is completed. The injection pipe 4 is withdrawn before the solidified material is completely cured.

The water block 7 formed by the above-described procedure has a diameter slightly larger than that of the vertical pipe 5 and closes the lower end of the vertical pipe 5. In the drawings, a part of the still water mass 7 enters the vertical pipe 5.

In the second embodiment of the vertical hole forming method of the present invention, the auger 1 has a special structure, that is, not only a continuous spiral blade 3 outside the rotary shaft 2 but also a rotary A source 8 having a chain-shaped crushed body 10 swingably connected to a central axis 9 of the rotation source 8 and rotating the crushed body 10 at a high speed to strike the ground at the tip thereof is used. The ground impact range is wider than the diameter of the vertical pipe 5 in the drawing, but may be slightly smaller than the diameter of the vertical pipe 5.

As a concrete representative example of the swingable connection, there is a method of connecting the crushed body 10 to the center shaft 9 with a pin. As another example, the crushed body 10 is formed in a chain shape. In other words, the concept includes a wire rope such as a wire rope that is fixed to the central axis as it is. In other words, if there is flexibility, it is possible to perform a movement similar to a rocking movement around a fixed portion.

In the third embodiment of the vertical hole forming method of the present invention, the injection means 4 uses the rotating shaft 2 having the inflow path 11 penetrating vertically.

The specific procedure of the third embodiment is basically the same as that of the first embodiment, and the solidified material is directly injected from the inflow passage 11 in the rotary shaft 2 without press-fitting the injection pipe 4. The only difference is the injection.

[0021]

According to the first aspect of the present invention, since a block of water is formed with the auger in the vertical pipe, the inflow of sediment into the vertical hole can be prevented. You only have to dig as deep as you can. Also, a vertical hole having a depth corresponding to the height of the tip of the auger during hardening of the solidifying material is accurately formed. Furthermore, since the water pressure which is going to enter the vertical pipe is received by the shearing force of the water-block, the volume of the water-block can be reduced as compared with the conventional case, and the amount of the solidified material is reduced. Therefore, it becomes more economical than before.

According to the second aspect of the present invention, since the injection pipe is inserted along the outer periphery of the vertical pipe, the vertical pipe plays a role of a guide, and the operation of inserting the injection pipe is facilitated.

According to the third aspect of the present invention, since the solidifying material is injected from the rotating shaft of the auger, the labor for inserting the injection pipe as in the second aspect of the present invention can be omitted, so that the injection operation is facilitated and the operation time is reduced. Is shortened. Further, even under conditions that are not suitable for inserting the injection pipe, that is, when the vertical hole is deep or the ground is relatively hard, construction can be performed.

According to the fourth aspect of the present invention, the impact caused by the impact of the crushed body rotating at high speed is transmitted, and the ground outside the vertical pipe is loosened, so that the work of inserting the injection pipe is further facilitated.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing showing a construction procedure of a first embodiment of a vertical hole forming method of the present invention, wherein FIG. The time when the solidified material is hardened while holding the auger in the vertical pipe is shown. (C) The figure shows the completed vertical hole.

FIGS. 2A and 2B are drawings showing a second embodiment of the vertical hole forming method of the present invention.
(A) is a cross-sectional view in the front direction when the solidification material is injected, (B)
The figure is a cross-sectional view in the side direction.

FIG. 3 is a drawing showing a third embodiment of the vertical hole forming method of the present invention, and is a cross-sectional view in the front direction when a solidifying material is injected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Auger 2 Rotary shaft 3 Spiral blade 4 Injection pipe (injection means) 5 Vertical pipe 7 Waterproof block 9 Central axis 10 Crushed body 11 Inflow path

Claims (4)

[Claims] After drilling in the vertical direction, the auger (1)
The solidification material is injected from the injection means (4) into the vicinity of the lower end of the vertical pipe (5) having the inside thereof, and the solidification material is formed by the spiral blade (3) whose auger tip projects downward from the lower end of the vertical pipe (5). Is stirred by the rotation of the auger (1) and the vertical pipe (5)
After hardening of the solidified material while having the auger (1) inside, and closing the lower end of the vertical pipe (5) with the water blocking mass (7) in which the solidified material is hardened, the auger (1) is connected to the vertical pipe (5). A vertical hole forming method characterized in that it is pulled out from a hole. 2. The vertical hole forming method according to claim 1, wherein the injection means is an injection pipe inserted along an outer periphery of the vertical pipe. 3. The vertical hole forming method according to claim 1, wherein the injection means (4) is a rotating shaft (2) of an auger (1) having an inflow passage (11) penetrating vertically. 4. The auger (1) has a spiral blade (3) outside a rotating shaft (2) and a crusher (10) that rotates at a high speed about a central axis (9). 4.) The vertical hole forming method according to claim 2 or 3, wherein the ground is hit at the tip of the crushed material (10).