JPH07269260A - Drilling method, method for settling pile, ground improving method, and excavating device therefor - Google Patents

Abstract

PURPOSE:To easily crush obstacles on drilling holes into the ground with effect of agitation for fixative liquid expected while preventing attachment of clay. CONSTITUTION:A hole is drilled to the ground with an excavating device 1 by rotary percussion excavation. In settling a pile, the pile 12 is settled into the drilled hole after the hole is drilled to the ground by rotary percussion excavation employing the excavating device 1. Improvement of the ground is made by ground improving method with a hole drilled to the ground with the excavating device 1, and the hole is drilled to the ground by rotary percussion excavation with the excavating device 1. Chemical liquid is desirable to be injected into the hole excavated by the rotary percussion excavation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sinking a pile and a method for improving the ground, and in particular, a drilling tool is used to drill a drilling hole, and various chemicals such as a fixing solution are injected therein to improve the ground. Or, it relates to a construction method for transmitting the load of a structure standing on the ground by sinking piles to the strong ground.

[0002]

2. Description of the Related Art Various types of ground improvement have been carried out in order to prevent subsidence and stability of the ground. Among them, the cement milk injection method is widely used because of its low noise and vibration. This cement milk injection method uses an earth auger (drilling tool) that is slightly larger than the pile diameter to make a hole while ejecting drilling fluid (bentonite, cement, water) from the tip of the auger, and after drilling to a specified depth. , The drilling liquid is switched to the root hardening liquid (cement milk) and a predetermined amount is injected into the hole bottom. After that, the auger is gradually pulled up while ejecting the pile circumference fixing liquid or the drilling liquid, and then the pile is set up in the drilling hole and gradually inserted to a predetermined depth.

In addition, RODEX (Rod avger excavatio
n) As for the construction method, a drilling rod with an enlarged bid and stirring blades is used, and pre-boring is performed while pouring the drilling fluid (mainly water) from the tip bid to provide a mud-drilled hole in the construction ground. Further, after expanding a predetermined supporting layer with an expanding bid, sand and gravel in the supporting layer are mixed and stirred while injecting a rooting solution to build an expanded bottom rooting bulb. After that, the piles are embedded in the excavation holes, the piles are fixed to the root-consolidating bulbs that are being built, and the piles and the support layer are integrated to develop the supporting force. This ROD
The EX method uses mud with rods or uses piles with open ends, so compared to the cement milk method,
It has the advantage of reducing the amount of soil discharged.

[0004]

However, the conventional construction methods such as the cement milk construction method and the RODEX construction method described above are
Since both are methods of drilling by rotating the excavation tool, it is preferable from the viewpoint of noise and vibration, but if there are hard boulders and concrete structures during excavation, it is impossible to excavate as it is , It was necessary to pull out the excavation tool from the drilling hole and insert another impact tool to fracture the obstacle. Such a work is not only extremely complicated, but also leads to a longer construction period.

Further, although the excavating tool is provided with an appropriate stirring blade, there are many cases where the mixing of various chemical solutions such as a fixing solution is insufficient only by stirring by rotating the stirring blade. Therefore, even if the pile is inserted, sufficient vertical supporting force cannot be obtained, and there is a problem that the effect of ground improvement becomes insufficient. In addition to this, when rotary drilling is performed, clay contained in soil adheres to drilling tools, rods, or stirring blades,
When excavating repeatedly, it was necessary to clean the excavation tool when it was pulled up.

The present invention has been made in view of the above problems of the prior art, and when drilling the ground,
Obstacles can be easily crushed, the effect of stirring fixed fluid, etc. can be expected, and further, the drilling method that can prevent clay from adhering, the pile digging method and the ground improvement method, and the excavation used for these methods. It is intended to provide a device.

[0007]

In order to achieve the above object, the boring method according to the present invention is characterized by boring the ground by rotary impact excavation using an excavating tool. The method of depositing a pile according to the present invention is characterized in that the ground is drilled by rotary impact drilling using a drilling tool, and then the pile is deposited in the drilled hole. The ground improvement method according to the present invention is characterized in that the ground is drilled by rotary impact drilling using the drilling tool in a method of drilling the ground using a drilling tool to improve the ground. It is preferable to inject a chemical solution into the hole drilled by the rotary impact drilling.

The excavating device according to the present invention comprises an excavating and stirring shaft that is rotatably provided, an excavating head that is provided at the tip of the excavating and stirring shaft, and a vibrator that vibrates the excavating and stirring shaft in the rotational and longitudinal directions. Have and. It is preferable that the excavation head has an ejection hole for ejecting the chemical liquid.

[0009]

In the boring method, the pile digging method, and the ground improvement method according to the present invention, since impact drilling is employed in addition to rotary drilling for drilling, there are obstacles such as boulders during the drilling. Even by hitting a drilling tool, this obstacle can be cut. Therefore, it is not necessary to replace the excavation tool each time, and the construction time can be shortened.

When various chemicals such as a fixing liquid are injected into the soil during or after drilling, the drilling tool itself vibrates in addition to the stirring effect of the stirring blades provided on the drilling tool. The stirring effect due to this vibration can be expected, and the mixing property between the chemical solution and the soil will be enhanced.

Further, a substance having high adhesiveness such as clay contained in soil easily adheres to the excavating tool at the time of boring, but in the method of the present invention, the excavating tool vibrates, so that it is applied to the tool or rod. The adhered clay or the like will be shaken off by the vibration, and it is not necessary to clean the drilling tool or the like when drilling next time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 (A) to 1 (H) are sectional views showing the steps of the ground improvement method of the present invention, and FIG. 2 is an enlarged sectional view of the essential parts showing the steps of FIG. 1 (B) (E).

First, as shown in FIG. 1 (A), an excavating tool 1 according to this embodiment is supported by a column 3 of a heavy-duty boring machine 2, and the excavating tool 1 is subjected to excavation or extraction. It is provided so as to move up and down with respect to the column 2. The excavation tool 1 has an excavation stirring shaft 4, an excavation head 5 attached to the tip thereof, and a drive unit 6 for rotating and vertically vibrating the shaft 4.

The excavation and agitation shaft 4 is provided with a spiral spiral car 7 at its tip portion, and agitates while excavating the earth and sand scraped by the excavation head 5 in a spiral shape. Further, a plurality of stirring blades 8 are provided at the base end portion of the shaft 4 and have a function of further stirring the earth and sand in the excavation hole drilled by the excavation head 5. However, in the present invention, the spiral car 7 is attached to the excavation stirring shaft 4.
1 and the stirring blade 8 need not be provided as shown in FIG.
Only one of them may be provided.

As shown in FIG. 2, the excavation head 5 attached to the tip of the excavation and agitation shaft 4 is provided with an ejection port 9 for ejecting various chemicals W such as a fixing liquid. Reference numeral 9 is formed so as to communicate with a chemical liquid supply source (not shown) via a flow path 10 formed in the shaft 4. Then, the excavating liquid is injected into the soil during excavation, or the fixing liquid is injected into the hole bottom when the hole is drilled to a predetermined depth.

By the way, the structure of the excavator described above is
It is an example for explaining the ground improvement method of the present invention and is not an essential requirement for the present invention. Therefore, the excavator used can be changed appropriately.

Next, the ground improvement method and the pile digging method of the present invention will be described. First, as shown in FIG. 1 (A), the excavation head 5 of the excavator is formed on the surface 11 of the ground to be perforated.
Is positioned and the driver 6 is operated to rotate the shaft 4 and vibrate up and down. In this state, as shown in FIG. 1B, the shaft 4 is gradually lowered and drilled. At this time, it is possible to excavate only by the rotating force and the striking force of the excavating head 5, but when the ground is relatively hard, the excavating liquid such as water may be discharged from the ejection port 9 of the excavating head 5. The excavation can be performed smoothly. As the drilling liquid, specifically, a liquid containing bentonite or the like as a main component is used.

As shown in FIG. 1 (C), when the hole is drilled to a certain depth, excavation is continued while discharging fixed fluid instead of excavation fluid. With this fixative, the pile 12 described later
The surrounding area will be solidified. As the fixing liquid, a liquid containing cement, bentonite, or the like as a main component is used.
When the excavation is continued in this way, the excavation head 5 reaches the target support layer 13 as shown in FIG. 1D, but when the excavation head 5 perforates to a predetermined depth, the surroundings of the piles that have been discharged until then are excavated. The fixing liquid for solidification is switched to the fixing liquid for root hardening, and the fixing liquid is discharged from the ejection port 9 of the excavation head 5. As a result, the rooting bulb portion 14 is built in the support layer 13 and its vicinity. As the fixing solution for root consolidation, a solution containing cement, bentonite or the like as a main component is used.

As described above, when boring to the target depth, the stirring effect by the stirring blades 8 and the spiral car 7 provided on the shaft 4 and the vertical vibration of the entire shaft including the excavation head 5 cause the vertical vibration of FIG. As shown in
The various chemicals W injected into the ground from the ejection port 9 of the excavation head 5 can be sufficiently agitated and mixed, and the fixing strength when the later-described pile 12 is inserted is increased.

Next, the shaft 4 is pulled out while rotating the shaft 4 in the same direction and vibrating vertically. That is, as shown in FIG. 1 (E), the shaft 4 is gradually pulled out from the perforated hole, and when it reaches the portion 15 around the pile where the fixing liquid for solidification is injected, it is discharged until then. The fixing solution for rooting is switched to the fixing solution for hardening around the pile, and the shaft 4 is continuously pulled out while discharging the fixing solution. Further, when reaching the vicinity of the surface 11 of the ground, the discharge of the fixing liquid is finished and the shaft 4 is pulled out as it is. As the solidifying fixing liquid around the pile, a liquid containing cement, bentonite or the like as a main component is used. In this way, various fixatives W are injected,
In addition, the drilled holes 16 that are sufficiently agitated and mixed can be formed (see FIG. 1F).

Particularly in this embodiment, as shown in FIG. 1 (E), even when the shaft 4 is pulled out, the shaft 4 is rotated and vertically vibrated, so that the stirring and mixing effect is further enhanced. . The drilling method according to the embodiment of the present invention ends at this stage. In the ground improvement method according to an embodiment of the present invention, by the above-mentioned construction method, at a predetermined interval in the ground, a plurality of holes are drilled, in the drilled holes, cement milk or the like is poured to form a pile. The ground is improved by molding.

In the pile digging method according to the embodiment of the present invention, after the hole is drilled as described above, the hollow pile 12 is finally inserted into the drilled hole 16 and the weight of the pile is reduced. Alternatively, the piles are laid down while giving a predetermined rotation, and the vertical supporting force of the pile 12 is secured by the fixing liquid 15 injected around the pile and the fixing liquid injected into the root consolidation bulb portion 14.

As described above, in the drilling method, ground improvement method and pile staking method of this embodiment, not only the excavating tool is rotated but also vertically vibrated when drilling, and so-called rotary impact excavation is used for excavation. Since the drilling is performed, the drilling speed is higher than that of the conventional rotary drilling, and even if there are boulders or concrete structures in the drilling process, the rocks can be easily cut by vertical vibration.

Further, since the excavating tool is accompanied by reciprocating motion by striking in addition to rotation, the effect of stirring with the soil when the fixing liquid is injected is increased, and clay or the like is less likely to adhere to the excavating tool. No need to clean with tools.

It should be noted that the embodiments described above are provided for facilitating the understanding of the present invention, and not for limiting the present invention. Therefore, each element disclosed in the above-described embodiments is intended to include all design changes and equivalents within the technical scope of the present invention.

For example, since the process shown in FIG. 1 shows one embodiment of the present invention, it is not necessary to make holes after drilling.
It is not necessary to stake the pile 12 as shown in FIGS. 1 (G) and (H). Further, the kind of the chemical liquid to be injected into the soil during the perforation and the timing of the injection are not limited to those of the embodiment shown in FIG. Furthermore, the ground improvement method of the present invention can be applied to, for example, tunnel construction as well as the case of perforating flat ground.

Furthermore, in the above embodiment, the chemical solution was injected into the drilled hole, but in the method of the present invention, it is not always necessary to inject the chemical solution. For example, the method of the present invention can be applied to a ground improvement method by applying a replacement method, a density increasing method, or the like, or a middle moat method in the pre-boring method. The replacement method is briefly described as a method of replacing a part or all of the soft soil with good quality soil. Briefly explaining the density increasing method, it is a method of applying a load to dehydrate water by the pressure or to perform compaction. The middle moat method of the pre-boring method will be briefly described as a method of pre-drilling a pile driving location.

[0028]

As described above, in the boring method, the pile digging method, and the ground improvement method according to the present invention, the ground is bored by the rotary impact excavation using the excavating tool. The drilling speed is faster than that of, and even if there are boulders or concrete structures in the middle of drilling, it is possible to easily cut.

Further, since the excavating tool is accompanied by reciprocating motion by striking in addition to rotation, the effect of stirring with the soil when the fixing liquid is injected is enhanced. Moreover, since clay or the like does not easily adhere to the excavating tool, it is not necessary to clean the excavating tool even if it is repeatedly used.

[Brief description of drawings]

1A to 1H are cross-sectional views showing the steps of the ground improvement method of the present invention.

FIG. 2 is an enlarged cross-sectional view of an essential part showing the step of FIGS.

[Explanation of symbols]

 1 ... Drilling tool 4 ... Shaft 5 ... Drilling head 6 ... Driving device

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[Procedure amendment]

[Submission date] April 7, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

FIG. 1 is a cross-sectional view showing a step of a ground improvement method of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Ishibashi 1528, Nakanishi, Yokoi, Kobe, Anpachi-gun, Gifu Prefecture Mitsubishi Materials Corporation Gifu Factory (72) Inventor Michio Tsuruta 25 Kamimizumoto-cho, Kumamoto-shi, Kumamoto −25 Inside Nishisu Co., Ltd.

Claims (7)

[Claims] 1. A drilling method for drilling a ground by rotary impact drilling using a drilling tool. 2. A method of drilling a pile, characterized in that the ground is drilled by rotary impact drilling using a drilling tool, and then the pile is submerged in the drilled hole. 3. A method for improving the ground, wherein the ground is drilled by using a drilling tool to improve the ground, and the ground is drilled by rotary impact drilling using the drilling tool. 4. The method of depositing a pile according to claim 2, wherein a chemical solution is injected into the hole drilled by the rotary impact excavation. 5. The ground improvement method according to claim 3, wherein a chemical solution is injected into the hole drilled by the rotary impact excavation. 6. An excavating device having a digging and stirring shaft rotatably provided, a digging head provided at a tip of the digging and stirring shaft, and a vibrator for rotating and oscillating the digging and stirring shaft in a longitudinal direction. 7. The excavating device according to claim 6, wherein the excavating head is provided with ejection holes for ejecting a chemical solution.