JPH05141168A - Auger for soil cement composite pile - Google Patents

Abstract

PURPOSE:To promote improvement in kneadability, reduction in power consumption and shortening in drilling time by forming a soil cement composite pile in the lower part of a drilling blade with an auger provided with a small diametral precedence drilling blade. CONSTITUTION:A hollow pipe 1, inserted with an auger rod through, is vertically set up in a specified position on the ground, and each of blades 5, 7, 9 is made into a state of being opened wide with each shear pin 13, connecting the upper end of an auger fulcrum shaft 3. Next, an auger head 20 is rotated forward as spraying a solidifier such as cement milk or the like into the ground from a nozzle 11 of the auger fulcrum shaft 3 or another nozzle 11a of a shaft 3a, and thereby the hollow pipe 1 is going to be installed in a soil cement pole being created after drilling and stirring the ground and going down. When the ground is drilled up to the specified depth, the solidifier is selected, forming a foot protection part. Finally the hollow pipe 1 is locked, and when the auger rod 2 is pulled out, stirring blade 9 in a widened state, the drag preventing blade 7 and the drilling blade 5 are all folded downward by cutting of the shear pin 13 and pulled out and removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auger for soil cement composite pile applied to foundation work related to construction.

[0002]

2. Description of the Related Art Hitherto, as an auger for soil cement composite pile, one shown in Japanese Patent Application No. 2-7064 has been proposed. In the soil cement composite pile auger, as shown in FIG. 7, a movable blade supporting member 35 is fixed to an auger support shaft 33 connected to a lower portion of an auger rod 32 in a hollow tube 31, and the movable blade supporting member 35 is The base ends of the auger movable blades 34 and 34A are pivotally attached to the auger movable blades 34 and 3A by a pivot 36.
The auger movable blade fixing shear pin 37, which is cut after the end of excavation and stirring, has the auger movable blades 34, 34A in which the tip side of 4A projects beyond the outer surface of the hollow tube 31 and is in an expanded state.
Auger movable blade support member 35 and auger movable blades 34, 34A
It has been inserted through and.

According to this auger for soil cement composite pile, during excavation and agitation (in this case, the discharge port 3 at the tip of the auger spindle is used).
While rotating and feeding the auger rod 32 while discharging the cement milk from 9, the hollow pipe (pile) 31 is simultaneously sunk.
Is fixed to the movable blade support member 35 by the shear pin 37 in a state where the auger movable blades 34 and 34A are expanded, and after the excavation and stirring is completed, the shear pin 37 is cut as shown in FIG. Since 34, 34A can be degenerated and the auger head can be collected on the ground through the hollow tube 31, not only can the soil cement column 38 having a larger outer diameter and a constant outer diameter be reliably formed. The hollow pipe 31 can be accurately embedded in the soil cement column while forming the soil cement column. In the figure, the central auger movable blade 34A is a co-rotation preventing blade that protrudes laterally beyond the tip of the movable blade 34.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to further improve the above-mentioned conventional example, to improve the kneading property, reduce the power consumption, and shorten the excavation time.

[0005]

In order to achieve the above object, the present invention provides an excavation blade on the tip side of an auger shaft connected to the lower part of an auger rod in a hollow tube and an outlet for solidifying material, In the auger provided with a co-rotation preventing blade and a stirring blade above the excavation blade and the stirring blade, the excavation blade and the stirring blade are pivotally attached to a support member fixed to the auger support shaft by a pivot, and the co-rotation preventing blade is an auger. The excavation blade, the stirring blade, and the co-rotation prevention blade are pivotally attached by a pivot to a support member rotatably loosely fitted to the support shaft. A preceding excavation blade that is held in a state and has an excavation diameter smaller than the excavation diameter of the excavation blade and that is erected outward at a right angle to the axis is provided.

Further, in order to easily excavate the hard intermediate layer even if there is a hard intermediate layer and agitate it with the solidifying material, and also to easily excavate the hard supporting layer with the solidifying material,
The lower end of the auger support shaft is conical, and a spiral excavation blade whose outer diameter is approximately the same as the outer diameter of the auger support shaft is provided in the conical portion.

Further, the preceding excavation blade is detachable so that it can be replaced when it is worn or damaged.

Further, in order to form a uniform soil cement composite pile, a jet of solidifying material is also provided on the auger shaft near the preceding excavation blade.

[0009]

[Operation] The ground is first excavated and stirred by a preceding excavation blade with a small excavation diameter, then excavated to a predetermined diameter by the excavation blade, stirred, mixed and stirred with the solidifying material ejected from the ejection port, and further well mixed by the stirring blade. Be stirred. The earth mass excavated between the excavation blade and the co-rotation prevention blade is prevented from co-rotation and shredded.

During excavation and stirring, the excavation blade, the stirring blade, and the co-rotation preventing blade are fixed to the support member by a shear pin in an expanded state. After the excavation and stirring is completed, the shear pin is cut to cut the excavation blade, the stirring blade, and The co-rotation prevention wing can be degenerated and the auger can be collected on the ground through the middle space.

Further, when the lower end of the auger shaft is formed into a conical shape and the conical portion is provided with a spiral excavating blade whose outer diameter is approximately the same as the outer diameter of the auger shaft, even if there is a hard intermediate layer. It is possible to excavate and stir to penetrate through the soil cement column, and excavate and stir the support layer to construct a soil cement composite pile that is embedded in the support layer.

If the preceding excavation blade is detachable, it can be replaced.

When a jet of the solidifying material is provided on the auger shaft near the preceding excavation blade, the solidifying material can be jetted from the jetting port, and a uniform soil cement column can be formed.

[0014]

The present invention will be described in detail below with reference to the illustrated embodiments. FIG. 1 shows a front view of an embodiment of the present invention, in which the auger support shaft 3 fixed to the lower end of an auger rod 2 arranged at the center of a hollow pipe 1 such as a vertical steel pipe pile has a tip end side. Leading blade 4, blade 5
A co-rotation prevention blade 7 and a stirring blade 9 are provided, and an auger head 20 is configured by providing a jetting port 11 for solidifying material such as cement milk on the auger spindle 3 near the excavation blade 5.

The excavation blade 4 has a diameter smaller than the diameter of the excavation blade 5 and smaller than the inner diameter of the hollow tube 1. For example, the excavation diameter of the excavation blade 5 is 1400.
It seems that the excavation diameter of the preceding excavation blade 4 is set to 700 mm with respect to mm. The diameter of the hollow tube 1 is smaller than that of the hollow tube 1 so that the auger head 20 can pass through the hollow tube 1 when it is collected upward. The attachment of the preceding excavation blade 4 may be parallel to or orthogonal to the excavation blade 5. In FIG. 1, the case of the parallel direction is shown by a chain double-dashed line, but the orthogonal direction is preferable for the contraction and closing of the excavation blade.

The excavation blade 5 and the stirring blade 9 are pivotally attached to a support member 6 fixed to the auger support shaft 3 by a pivot 12.
In a state where the excavation blade 5 and the stirring blade 9 are expanded (horizontally arranged), they are held in an expanded state by the shear pin 13, and in the expanded state, they project outward from the outer surface of the hollow tube 1. ing.

The co-rotation preventing blade 7 is pivotally attached to a support member 8 rotatably fitted on the auger support shaft 3 by a pivot shaft 12, and is held in an expanded state by a shear pin 13. The co-rotation prevention blade 7 has a diameter longer than that of the excavation blade 5,
Prevents co-rotation of excavated soil by protruding from the diameter of the excavation hole, engaging with the ground that has not been excavated during excavation, and being in a stationary state even if the preceding excavation blade 4, the excavation blade 5 and the stirring blade 9 rotate Is.

The excavation blade 5, the co-rotation prevention blade 7 and the stirring blade 9 are held in the expanded state by the shear pin 13.
Excavation and stirring are performed in the expanded state (horizontal position), and after the completion of excavation and stirring, the shear pin 13 is cut, and the pivot 12 is rotated to the contracted position as shown by the chain line in FIG. This is because the diameter is made smaller than the inner diameter of the hollow tube 1 so that it can be collected on the ground through the hollow tube 1. When the auger head 2 is pulled up by the auger rod 2 via the auger support shaft 3, the shear pin 13 is provided with a stirring blade 9 and a co-rotation preventing blade 7.
Then, the excavation blade 5 is sequentially locked to the lower end of the hollow tube 1 and cut. Therefore, the shear pin 13 is provided with an annular V groove (not shown) for shearing at the sheared position in order to make cutting relatively easy and reliable.

Further, the lower end of the auger support shaft 3 may be formed in a conical shape, and the conical portion 14 may be provided with a spiral excavating blade 15 having an outer diameter substantially equal to the outer diameter of the auger support shaft 3. In this case, excavation and stirring can be reliably performed even in the hard intermediate layer and the hard support layer.

The spiral excavation blade 15 is provided on the shaft 3a which is separate from the auger support shaft 3 together with the preceding excavation blade 4, and the shaft 3a is detachably fixed to the lower end of the auger support shaft 3. May be. In this case, there is an advantage that it can be replaced when it is worn or damaged. When the auger support shaft 3 is wholly formed and provided on the auger support shaft 3, at least the preceding excavation blade 4 may be detachable. The shaft 3a is provided with a jet port 11a. When the auger shaft 3 is provided with the jet port 11 and the shaft 3a is also provided with the jet port 11a, one of the jet ports is blind. To use.

Next, a construction example of constructing a soil cement composite pile using the auger for soil cement composite pile of the present invention will be explained with reference to FIGS. A device for giving a force to rotate and feed the auger head 20 and to support and hollow the hollow tube 1 is
Since it is publicly known, its explanation is omitted. First, as shown in FIG. 2, at a predetermined position on the ground, a hollow tube 1 having an auger rod 2 inserted through an inner central axis thereof is vertically arranged and each blade 5,
The upper end portion of the auger support shaft 3 of the auger in which the shear pins 13 hold the members 7 and 9 in an expanded state is connected to the lower end portion of the auger rod 2.

Next, as shown in FIG. 3, while the solidifying material such as cement milk is jetted into the ground from the jet port 11 of the auger shaft 3 or the jet port 11a of the shaft 3a, the auger head 20 is passed through the auger rod 2. When the hollow tube 1, the auger rod 2 and the auger head 20 are descended by rotating and feeding the ground, the soil of the ground and the solidified material are forcibly stirred,
Soil cement column 16 having an outer diameter larger than that of the hollow tube 1
The hollow pipe 1 is embedded in the soil cement column 16 while being manufactured. At this time, the ground is first excavated by the preceding rotary excavation blade 4 and excavated to a predetermined diameter by the next rotational advance excavation blade 5, and the excavated earth mass is restrained by the rotating excavation blade 5. It is shredded between the co-rotation prevention blade 7 and the spout 11 or the spout 11a.
The soil is well mixed with the solidified material ejected from the soil, and the co-rotation preventing blade 7 prevents the soil from co-rotating, so that the soil is further mixed and stirred by the rotating stirring blade 9 to form a uniform soil cement column 16.

When the hole has been drilled to a predetermined depth, the feeding of the hollow tube 1 and the auger rod 2 is stopped, and the bottom of the hole is drilled by switching to a slurry-like solidified material having a higher compressive strength after solidification than the solidified material injected until then. It is filled with a solidifying material to form the root hardening portion 16a. In this case, the auger does not feed, but it is better to rotate it. In addition, when the root consolidation portion 16a is formed, when the hole is drilled to a depth shallower by a distance of the root consolidation portion 16a at the bottom of the hole than the predetermined depth, the compressive strength after solidification is larger than that of the solidified material injected until then. Switch to solidifying material, root hardening part 1
It may be formed by injecting the solidifying material for a distance of 6a and drilling to a predetermined depth.

Next, when the hollow pipe 1 is drilled to a predetermined depth and the hollow pipe 1 reaches the predetermined depth, as shown in FIG. 5, a means 17 for temporarily fixing the hollow pipe 1, such as a hydraulic jack, is pressed downward. Or hold it with a hydraulic chuck or the like and fix it, and then lift the auger rod 2. Then, the stirring blade 9, the co-rotation prevention blade 7 and the excavation blade 5 which are held in the expanded state by the shear pin 13 sequentially abut against the lower end portion of the intermediate space 1 and the shear pin 13 is cut, so that the shear pin 13 is folded downward and retracts. Then, it is pulled up through the hollow tube 1 and withdrawn. Fig. 4 shows the state when the auger rod 2 is started to be lifted, and the stirring blade 9
Is a state in which the shear pin 13 is cut by hitting the lower end of the hollow tube 1 and the stirring blade 9 begins to contract and close. Next, as shown in FIG. 6, the hollow tube 1 is inserted into the root-hardening portion 16a into which the solidifying material having a high compressive strength after solidification is injected, and the soil cement composite pile 18 is completed.

When burying the hollow tube 1, the weight of the hollow tube 1 or the force input may be used, or the hollow tube 1 may be rotated. Further, in the embodiment shown in FIG. 1, the stirring blade is provided above the co-rotation preventing blade 7, but the positions of the co-rotation preventing blade 7 and the stirring blade 9 may be exchanged. Further, the stirring blade 9 may have a plurality of stages instead of one stage.

Next, in order to show the effect of the present invention, the following effect test was conducted using the embodiment shown in FIG. 1 and the conventional example shown in FIG. 7 as a comparative example. The drilling depth, ground layer, and N value were as shown in FIGS. 9 and 10. The test results of the digging speed are as shown in FIG. FIG. 11 shows the excavation time per unit length, and it can be understood that the excavation speed in this example is high especially in the support layer having an N value of more than 50. Further, the test result of the current consumption of the auger motor is as shown in FIG. 12, and it can be understood that the current consumption of the present example is small in the hard ground with the N value exceeding 20 to 30. Furthermore, if arranged by current / digging speed which is an index of power consumption per unit excavation length, it is as shown in FIG. 13, and N value is 40.
It can be understood that the present embodiment is far smaller in power consumption and economical than the prior art in the hard ground exceeding the above range. 11 to 13, a solid line showing a curve of the graph shows the embodiment of the present invention, and a broken line shows the conventional example.
In FIGS. 14 and 15, reference numeral 100 is a cohesive soil mass, reference numeral 1
01 (indicated by dots) indicates a uniform soil cement.

[0027]

As described above, according to the present invention, during excavation and stirring, the excavation blade, the co-rotation prevention blade and the stirring blade are fixed by shear pins in the expanded state (horizontal position state), and after the excavation and stirring is completed, By cutting the shear pin, the excavation blade, the co-rotation prevention blade and the stirring blade are folded and retracted, and the auger head can be withdrawn through the hollow pipe. Therefore,
It is possible to simultaneously bury the hollow tube with high accuracy while constructing a soil cement column having a predetermined outer diameter larger than the outer diameter of the hollow tube. Moreover, a reliable and high-bearing soil cement pile can be constructed reliably and easily without noise and vibration. In addition, since the preceding excavation blade having a smaller excavation diameter than the excavation blade is provided below the excavation blade, first, the excavation blade having a smaller diameter is excavated, and then the excavation blade is excavated to a predetermined diameter. It will be. For this reason, since the digging speed is increased, the construction efficiency is improved and the construction period can be shortened. It is economical because the excavation of hard ground is easy and the power consumption of the auger motor is low. Moreover, since the power consumption is small, it is possible to perform construction with an auger motor having a small capacity.
Further, the leading excavation blade can be replaced when worn or damaged.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a process diagram showing a construction order of soil cement composite piles.

FIG. 3 is a next step diagram showing a construction order of soil cement composite piles.

FIG. 4 is a next step diagram showing the construction order of soil cement composite piles.

FIG. 5 is a next step diagram showing a construction order of soil cement composite piles.

FIG. 6 is a next step diagram showing a construction order of soil cement composite piles.

FIG. 7 is a front view showing a conventional example.

FIG. 8 is a front view showing a usage state of a conventional example.

FIG. 9 is a graph showing the N value with respect to the depth of the test formation,
Represents a depth of up to 20 m.

FIG. 10 is a graph showing the N value with respect to the depth of the test formation, showing the depth from 20 m to 40 m.

FIG. 11 is a graph showing the excavation time per unit length when constructing a soil cement composite pile using the auger of the example of the present invention and the conventional example.

FIG. 12 is a graph showing a current consumption value of an auger motor when a soil cement composite pile is constructed using the auger of the embodiment of the present invention and the conventional example.

FIG. 13 is a graph showing the current / digging speed of the auger motor when constructing a soil cement composite pile using the auger of the example of the present invention and the conventional example.

[Explanation of symbols]

 1 Hollow Tube 2 Auger Rod 3 Auger Shaft 3a Shaft 4 Leading Excavation Blade 5 Excavation Blade 6 Supporting Member 7 Co-rotation Preventing Blade 8 Supporting Member 9 Stirring Blade 11 Spout 11a Spout 12 Shaft 13 Sharp Pin 15 Spiral Excavation Blade 20 Auger head

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000001052 Kubota Co., Ltd. 1-247 Shikitsu East, Naniwa-ku, Osaka-shi, Osaka (71) Applicant 000133881 2-4-1 Akasaka, Minato-ku, Tokyo (72) Inventor Ryukichi Ishibashi 2683-3 Ishikawa-cho, Hachioji-shi, Tokyo Inside the Hachioji Proving Ground, housing and capital maintenance corporation (72) Inventor Shigeki Terasaki 2-3-6 Otemachi, Chiyoda-ku, Tokyo New Within Nippon Steel Co., Ltd. (72) Inventor Hajime Shimazaki 2-6-3 Otemachi, Chiyoda-ku, Tokyo Within Nippon Steel Co., Ltd. (72) Inventor Yuichi Imaeda Sanbonmatsu, Atsuta-ku, Nagoya-shi, Aichi Prefecture No. 1-1, Japan Vehicle Manufacturing Co., Ltd. (72) Masahiro Nakajima 1-1, Sanbonmatsucho, Atsuta-ku, Nagoya-shi, Aichi Prefecture Japan Vehicle Manufacturing Co., Ltd. (72) Inventor Anbu Takeshi Shun 4 Takaya Shinmachi, Ichikawa, Chiba Prefecture Kubota Ichikawa Plant, Inc. (72) Inventor Mitsugu Otsuki 4 Takaya Shinmachi, Ichikawa City, Chiba Prefecture Kubota Ichikawa, Ltd. (72) Inventor Hibino Shinichi Tokyo 2-4-1, Akasaka, Minato-ku, Tokyo Tenox Co., Ltd. (72) History of the inventor, 2-4-1, Akasaka, Minato-ku, Tokyo Tenox, Co., Ltd.

Claims (4)

[Claims] 1. An excavation blade is provided on the tip side of an auger spindle connected to the lower portion of an auger rod in a hollow tube, a jetting port for solidifying material is provided, and a co-rotation preventing blade and a stirring blade are provided above it. In the auger, the excavation blade and the stirring blade are
The co-rotation preventive blade is pivotally attached to a support member fixed to the auger support shaft by the pivot shaft, and the co-rotation preventing blade is pivotally attached to the support member freely rotatably fitted to the auger support shaft by the pivot shaft. The co-rotation preventive blade is held in an expanded state by inserting a fixing shear pin that is cut after the end of excavation across the respective support members, and is below the excavating blade at a right angle with an excavating diameter smaller than the excavating diameter of the excavating blade. An auger for soil cement composite piles, characterized in that it is provided with a preceding excavation blade standing upright on the outside. 2. The soil according to claim 1, wherein the lower end of the auger support shaft has a conical shape, and the conical portion is provided with a spiral excavating blade whose outer shape is approximately the same as the outer diameter of the auger support shaft. Auger for cement composite pile. 3. The auger for soil cement composite piles according to claim 1, wherein the preceding excavation blade is detachably attached to the auger shaft. 4. The auger for soil cement composite piles according to claim 1, wherein the auger shaft near the preceding excavation blade is provided with a jet of a solidifying material.