JP2920436B2 - Auger for mid-digging soil cement composite pile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, an auger for a soil cement composite pile is disclosed in Japanese Patent Application No. 2-7064. In this soil cement composite pile auger, as shown in FIG. 7, a movable blade support member 35 is fixed to an auger support shaft 33 connected to a lower portion of an auger rod in a hollow tube 31, and the movable blade support member 35 The base end of the auger movable blade 34 is the pivot 3
6 for fixing the auger movable blade 34 which is sheared after the end of the excavation and stirring in the auger movable blade expanded state (horizontal position state) in which the tip side of the auger movable blade 34 projects beyond the outer surface of the hollow tube 31. A shear pin 37 is inserted through the auger movable blade support member 35 and the auger movable blade 34 to constitute the auger head 40. In addition, in FIG.
Reference numeral 8 denotes a spout of a solidified material such as cement milk, and 39 denotes a screw head provided at the tip of the auger support shaft 33.

According to the soil cement composite pile auger, during excavation and stirring, the auger movable blade 34 is fixed to the movable blade support member 35 with the shear pin 37 in an expanded state,
After completion of the excavation and stirring, as shown in FIG.
The auger movable blade 34 is contracted by shearing, and the auger head 40 can be collected on the ground through the hollow tube 31. Therefore, the soil cement column 41 having a larger outer diameter and a constant outer diameter than the hollow tube 31 is formed. Not only can you create it reliably,
The hollow tube 31 can be accurately embedded in the soil cement column while forming the soil cement column.

However, in the above-mentioned auger for a soil cement composite pile, all the auger movable blades 34 rotate in the same direction to excavate and agitate. There is a disadvantage that the stirring and mixing state is deteriorated and the strength of the soil cement column is insufficient.

In this application, as shown in FIG. 9, a support member 35A is rotatably mounted on the auger support shaft 33 at a position adjacent to the movable blade support member 35 in the vertical direction, and the support member 35A is attached to the support member 35A. In a state in which the base end portion of the agitating auxiliary wing 34A is pivotally connected by the pivot 36, and the tip of the agitating auxiliary wing 34A protrudes laterally beyond the tip of the auger movable blade 34, the agitation assist is sheared after the end of the excavation and agitation. The blade fixing shear pin 36A includes the support member 35A and the stirring auxiliary blade 3
There has been proposed an auger for a soil cement composite pile inserted through the base end of 4A. According to the auger for a soil cement composite pile, the agitating auxiliary blade 34A serves as a co-rotation prevention blade, so that co-rotation of the soil can be prevented.

[0006]

However, the agitating auxiliary blades 34A of the conventional auger for soil cement composite piles described above.
Is larger than the diameter of the drilling hole, it bites into the ground and becomes stationary, and only prevents co-rotation.Therefore, there is a disadvantage that shredding of viscous soil and stirring and mixing are not sufficient, and the auger is movable. Since all the blades 34 have the same diameter, there are inconveniences such as a large digging load, a long digging time, and a high power consumption. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an auger for a middig soil cement composite pile that solves the above-mentioned disadvantages.

[0007]

In order to achieve the above object, the present invention provides an excavating wing at the lower part of an auger rod in a hollow pipe such as a steel pipe pile and a concrete pipe pile, and an injection port of a solidified material. In an auger having a stirring blade provided above a drilling wing, the auger rod is a double tube rod of an inner rod and an outer rod that can rotate with each other, and the drilling wing is pivotally mounted on a support member fixed to the inner rod. The agitating blade is pivotally attached to a supporting member fixed to the outer rod by a pivot, and is sheared after the excavation and stirring. The configuration of claim 1, wherein the outer diameter of the excavating blade and the stirring blade in the expanded state is held larger than the outer diameter of the hollow tube by the fixed shear pin. Inner rod below the excavation wing And a lower excavation wing having a smaller diameter than the excavation wing, wherein the lower end of the inner rod constituting the auger rod is formed in a conical shape, and the conical portion has a larger outer diameter than the inner rod. 4. The configuration according to claim 3, wherein a spiral excavation wing having substantially the same outer diameter is provided.
The auger rod according to claim 4, wherein at least one stabilizer whose outer diameter is in sliding contact with the inside of the hollow tube is rotatably provided.

[0008]

[Function] The auger head provided at the lower part of the auger rod inserted into a hollow pipe such as a steel pipe pile or a concrete pile is rotated and fed, and excavation is performed. While forming a soil cement column, a hollow pipe is fed and buried in the soil cement column to form a soil cement composite pile.

[0009] In constructing the soil cement composite pile, first, the pile is excavated to a predetermined diameter by a drilling wing, and then mixed and stirred with a solidified material ejected from an ejection port by a stirring wing. At this time, the excavating wing is provided on the inner rod and the stirring wing is provided on the outer rod, and rotates in opposite directions to perform digging, stirring and co-rotation.

During excavation and stirring, the excavator blades and the impeller blades are fixed to the support member in an expanded state (horizontal position) by a shear pin. Can be recovered on the ground through

In the case where the lower end of the inner rod constituting the auger rod is formed in a conical shape, and a spiral excavating wing having the same outer diameter as the inner rod is provided in this conical portion, the solid intermediate portion is formed. Even if there is a layer, excavation and agitation can be performed through the soil cement column, and a solid support layer can be excavated and agitated to form a soil cement composite pile embedded in the support layer.

When the auger rod is provided with a stabilizer having an outer diameter that is in sliding contact with the inside of the hollow tube, the runout of the hollow tube during excavation can be prevented and the auger rod can be prevented from bending.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows a front view of an embodiment of the present invention, in which a lower portion of an auger rod 2 arranged at the center of a hollow pipe 1 such as a vertical steel pipe pile or a concrete pipe pile has a predetermined distance above the tip side. , The pre-drilling blade 5, the drilling blade 6 and the stirring blade 7
Is provided, and an auger rod 20 near the excavating wing 6 is provided with an ejection port 12 of a solidified material such as cement milk to form an auger head 20.

The auger rod 2 is constituted by a double tube rod composed of an inner rod 3 and an outer rod 4 which are rotatable with respect to each other, and the preceding excavation wing 5 and the excavation wing 6 have an inner rod 3 projecting downward from the outer rod. In addition, the stirring blade 7 is provided on the outer rod 4. This is because the leading excavator 5 and the excavator 6 and the impeller 7
Are to be rotated in directions opposite to each other.

The preceding excavator blade 5 has a smaller excavation diameter than the excavation diameter of the excavator blade 6 and smaller than the inner diameter of the hollow tube 1. For example, if the inner diameter of the hollow pipe 1 is 1000 mm, the excavation diameter of the leading excavation blade 5 is set to 700 mm with respect to the excavation diameter of the excavation blade 6 of 1400 mm. Here, the reason for making the diameter smaller than the inner diameter of the hollow tube 1 is that the auger head 2
This is so as to be able to pass through when collecting 0 upward through the hollow tube 1. The installation of the preceding excavation wing 5 is arbitrary in a direction parallel or orthogonal to the excavation wing 6 as long as it is horizontal.

The excavating wing 6 is pivotally connected to a supporting member 8 fixed to the inner rod 3 of the double tube rod constituting the auger rod 2 by a pivot 10 so that the excavating wing 6 is in an expanded state (horizontal arrangement). In the expanded state), and is held in the expanded state by the shear pin 11, and in the expanded state, protrudes outside the outer surface of the hollow tube 1. The portion of the inner rod 3 a where the preceding excavation wing 5 and the excavation wing 6 are provided may be a support shaft connected to the inner rod 3.

The stirring blade 7 is pivotally connected to a support member 9 fixed to the outer rod 4 of the double tube rod constituting the auger rod 2 by a pivot 10 so that the stirring blade 7 is in an expanded state (horizontal position state). ), Is held in the expanded state by the shear pin 11, and in the expanded state, projects outside the outer surface of the hollow tube 1. The number of the stirring blades 7 may be not only one but also a plurality of stages. In FIG. 1, it is provided in two stages. The stirring blade 7 rotates in a direction opposite to that of the excavation blade 6 to perform stirring and prevent co-rotation.

The reason why the excavating blade 6 and the stirring blade 7 are held in the expanded state by the shear pin 11 is that excavation, stirring, and prevention of co-rotation are performed in the expanded state.
This is because the shear pin 11 is sheared to rotate and retract around the pivot 10 as shown by a chain line in FIG. 1 so that the shear pin 11 can pass through the hollow tube 1 when retracted to the ground. When the auger head 20 is pulled up together with the auger rod 2, the agitating blade 7 and the excavating blade 6 of the shear pin 11 are engaged with the lower end of the hollow tube 1 and sheared. Therefore, the shear pin 11 is provided with an annular V-shaped groove (not shown) for shearing at a position to be sheared in order to make shearing relatively easy and reliable.

The inner rod 3 of the double tube rod constituting the auger rod 2 projecting downward from the outer rod 4 so that the hard intermediate layer and the hard support layer can be reliably excavated and stirred. The lower end (tip) is formed in a conical shape,
The conical portion 13 may be provided with a spiral digging wing 14 having a substantially same outer diameter as the outer diameter of the inner rod 3 even if the outer diameter is large. Furthermore, a stabilizer 15 may be provided in the auger rod 2 at least one stage so as to be freely rotatable. The stabilizer 15 is set so that the outer diameter thereof is in sliding contact with the inside of the hollow tube 1, and prevents the core tube from deflecting during excavation and also prevents the auger rod 2 from bending.

Next, an example of construction of a soil cement composite pile using the auger for soil cement composite pile will be described with reference to FIGS. 2 to 6. Giving a turning force and a feeding force to the auger rod 2,
A device for rotating and feeding the hollow tube 1 and the auger head 20 is well known, and thus the description thereof is omitted. First, as shown in FIG. 2, the hollow tube 1 with the auger rod 2 provided with the auger head 20 at the lower part positioned at the center axis and inserted therethrough is vertically arranged at a predetermined position on the ground, and rotated and supplied. The upper ends of the hollow tube 1 and the auger rod 2 are gripped by a known working machine (not shown) to be advanced.

Next, as shown in FIG. 3, while the solidified material such as cement milk is spouted into the ground from the spout of the auger rod 2, the hollow tube 1 is fed and auged by a working machine (not shown). When the rod 2 is rotated and advanced, the soil of the ground and the solidified material are forcibly excavated and stirred by the rotating auger head 20, and the soil cement column 16 having an outer diameter larger than the outer diameter of the hollow pipe 1 is formed. The hollow tube 1 is buried in the soil cement column 16 while being formed. At this time, the ground is first excavated by the rotary excavating wing 5 and excavated to a predetermined diameter by the next rotary excavating wing 6, and the excavated soil is rotated by the rotating excavating wing 6 and the excavating wing 6. In the opposite direction, the shredder 7 is forcibly shredded with the rotating agitating blade 7, the soil is prevented from rotating around the agitating blade 7, and is thoroughly stirred and mixed with the solidified material spouted from the spout 12. Pillars 16 are created. In particular, the agitating blade 7 rotates in the opposite direction to the excavating blade 6, so that the excavated soil is more finely chopped, and the solidified material is also better agitated and mixed, so that a more uniform soil cement column 16 is formed. Is done.

When the feed is performed to a predetermined depth, the feed of the hollow tube 1 and the auger rod 2 is stopped as shown in FIG. 4, and the compressive strength after the solidification is switched to a solidified material larger than the solidified material injected up to that time to cut. The bottom of the hole is filled with the solidifying material and the
a is formed. In this case, the auger does not feed, but it is better to rotate it. Further, the formation of the root consolidation part 16a is such that when drilled to a depth shallower than the predetermined depth by the distance of the root consolidation part 16a at the bottom of the hole, the compressive strength after solidification is larger than that of the solidified material injected up to that point. It may be formed by switching to a solidified material and drilling a hole to a predetermined depth while injecting the solidified material for the distance of the root compaction portion 16a.

Next, when the hole is drilled to a predetermined depth and the hollow tube 1 reaches the predetermined depth, as shown in FIG. 5, means 17 for temporarily fixing the hollow tube 1, for example, pressing with a hydraulic jack, Hold it with a hydraulic chuck or the like and fix it.
Withdraw. Then, the stirring blade 7 and the excavating blade 6 held in the expanded state by the shear pin 11 sequentially abut against the lower end of the hollow tube 1 and the shear pin 11 is sheared. Retrieve through 1 and withdraw to the ground. Then, as shown in FIG. 6, the hollow pipe 1 is inserted into the solidified portion 16 a into which the solidified material having a high compressive strength after solidification is injected, and the soil cement composite pile 18 is completed. When the stabilizer 15 is provided in the construction of the soil cement composite pile 18, the core runout of the hollow pipe 1 and the bending of the auger rod 2 are prevented, and the verticality is reliably maintained. In burying the hollow tube 1,
The hollow tube 1 may use its own weight or press input, or may be rotated.

[0024]

As described above, according to the present invention, an auger rod provided with a drilling blade and a stirring blade at the bottom is inserted into a hollow pipe such as a steel pipe pile or a concrete pipe pile, and the hollow pipe is fed. Rotate and feed the rod, excavate, squirt solidified material from the auger rod spout, agitate the excavated soil, embed a hollow tube in this soil cement column and form a soil cement composite pile Can be created. Moreover, since the stirring blade is provided on the outer rod of the double tube rod constituting the auger rod, it rotates in the opposite direction to the rotation of the drilling blade to excavate and also performs stirring and rotation prevention,
The excavated soil is also pulverized more finely, and is more uniformly stirred and mixed with the ejected solidified material to form a uniform soil cement column. Further, the agitating blade and the excavating wing are held in an expanded state (horizontal position state) by the shear pin during the excavating and stirring, and can be folded and retracted by shearing the shear pin after the excavating and stirring. Can be withdrawn through the hollow tube to the ground.
Therefore, a soil cement composite pile having a diameter larger than that of the hollow pipe and having high reliability and high bearing capacity can be reliably and easily constructed without noise and vibration.

Further, since a leading excavator having a smaller excavation diameter than the excavator is provided below, the excavator is first excavated with a smaller excavator, and then excavated to a predetermined diameter with the excavator. For this reason, since the excavation load is not applied at once, the excavation speed is increased, the current consumption of the auger motor is small,
This has the effect that the current / speed ratio is small. Further, the lower end (tip) of the auger rod is formed in a conical shape, and a spiral excavation blade having a diameter substantially equal to the outer diameter of the auger rod is provided in the conical portion. Excavation and agitation can be reliably performed even on the layer and the hard support layer, and the soil cement composite pile embedded in the support layer can be reliably formed. Furthermore, since the stabilizer is provided in the middle of the auger rod, the core tube of the hollow tube and the bending of the auger rod are prevented,
The verticality is reliably maintained, and the soil cement composite pile is created.

[Brief description of the 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 a soil cement composite pile.

FIG. 3 is a next process diagram showing a forming order of the soil cement composite pile.

FIG. 4 is a next process diagram showing a construction order of the soil cement composite pile.

FIG. 5 is a next process diagram showing a construction order of the soil cement composite pile.

FIG. 6 is a next process diagram showing the construction order of the soil cement composite pile.

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

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

FIG. 9 is a front view showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow tube 2 Auger rod 3 Inner rod 4 Outer rod 5 Advance drilling blade 6 Cutting blade 7 Stirring blade 8 Support member 9 Support member 10 Axis 11 Sharpin 12 Spout port 13 Conical part 14 Spiral drilling blade 15 Stabilizer 20 Auger head

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) E02D 7/00 E02D 3/12 102 E02D 5/46 E21B 7/20 E21B 10/32

Claims (4)

(57) [Claims] 1. An auger comprising a drilling wing provided at a lower portion of an auger rod in a hollow pipe such as a steel pipe pile or a concrete pipe pile, a solid material injection port provided, and a stirring blade provided above the drilling wing. The auger rod is a double tube rod of an inner rod and an outer rod that are rotatable with each other, and the excavating wing is pivotally attached to a support member fixed to the inner rod by a pivot, and is sheared after excavation and stirring is completed. The stirring blade is pivotally attached to a support member fixed to an outer rod by a pivot, and is held in an expanded state by a fixing shear pin which is sheared after the end of the excavation and stirring. An auger for a soil-drilling soil cement composite pile, wherein the outer diameter of the blade and the stirring blade in the expanded state is larger than the outer diameter of the hollow tube. 2. A digging wing having a smaller diameter than the digging wing is provided on the inner rod below the digging wing.
The auger for the described medium-digging soil cement composite pile. 3. A lower end of an inner rod constituting an auger rod is formed in a conical shape, and a spiral excavation wing having an outer diameter which is substantially equal to the outer diameter of the inner rod is provided in the conical portion. The auger for a mid-soil soil cement composite pile according to claim 1 or 2. 4. The pile according to claim 1, wherein said auger rod is provided with at least one stabilizer rotatably slidably in contact with the inside of said hollow tube. For auger.