JP2887702B2 - Method and apparatus for constructing 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 a method and an apparatus for forming a soil cement composite pile applied to construction-related foundation work.

[0002]

2. Description of the Related Art Conventionally, as a method for forming a soil cement composite pile, an auger for construction of a soil cement composite pile shown in Japanese Patent Application No. 2-7064 has been proposed. In this auger for construction of a soil cement composite pile, as shown in FIG. 11, a movable blade support 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 support member is provided. The base end of the movable auger blade 34 is pivotally connected to the base 35 by a pivot 36, and the distal end of the movable auger blade 34 protrudes beyond the outer surface of the hollow tube 31. The auger movable blade fixing shear pin 37, which is cut after the excavation and stirring is completed, is auger movable blade support member 35.
And the auger movable blade 34 to constitute the auger head 40. In the figure, 38 is a discharge port of a solidified material such as cement milk, and 39 is an auger support shaft 3.
3 is a screw head provided at the distal end.

According to this soil cement composite pile construction auger, during excavation and stirring, the auger movable blade 34 is fixed to the movable blade support member 35 in an expanded state by a shear pin 37, and after completion of excavation and stirring, By cutting the shear pin 37 as shown in FIG. 12, the auger movable blade 34 is contracted and closed, and the auger head 40 can be collected on the ground through the hollow tube 31. Not only can the soil cement column 41 having the outer diameter be reliably formed, but also the hollow tube 31 can be embedded accurately in the soil cement column while forming the soil cement column.

However, in the auger for soil cement composite pile construction, all the auger movable blades 34 rotate in the same direction to excavate and agitate. As a result, 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, 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 as shown in FIG. The base end of the anti-rotation wing 34A is pivotally connected by a pivot 36A.
In the state where the tip of A protrudes laterally beyond the tip of the auger movable blade 34, the co-rotation-prevention wing fixing shear pin 37A that is cut after the end of the excavation and stirring is formed by the support member 35A and the co-rotation prevention wing 34A. There has been proposed an auger for soil cement composite pile construction that is inserted through the end.
According to the auger for constructing the soil cement composite pile, the co-rotation preventing wing 34A is restricted from rotating by the ground, so that co-rotation of the soil can be prevented.

[0006]

However, the conventional augmenting blades 34A of the conventional auger for soil cement application.
Is larger than the drilling diameter, so that it bites into the ground and becomes stationary, and only prevents co-rotation.Therefore, there is an inconvenience that shredding of viscous soil and stirring and mixing are not sufficient. Since they all have the same diameter, there are inconveniences such as a large digging load, a long digging time, and a high power consumption. An object of the present invention is to provide a method and apparatus for constructing a soil cement composite pile that solves the above-mentioned disadvantages in view of the above points.

[0007]

According to the present invention, in order to achieve the above object, an auger head is provided at the tip of an auger rod and has an outer diameter smaller than the inner diameter of a hollow pipe such as a steel pipe pile or a concrete pile. A wing, a spout of solidified material such as cement milk provided on an auger rod near the digging wing, and a reversing digging wing rotatably provided above the digging wing and engaged with the lower end of the hollow pipe. The inverted drilling wing has an outer diameter in an expanded state that is at least substantially the same as the outer diameter of the hollow tube, and is pivotally attached to a support member rotatably and loosely fitted to an auger rod. Inserting the auger head into a hollow pipe such as a steel pipe pile or a concrete pile having a transmission member at the lower end thereof, with the auger head preceding the auger head. And the auger rod The work machine grips the upper ends of the hollow pipes, rotates the auger rod and the hollow pipe in opposite directions, and rotates the hollow pipe through the transmission member of the hollow pipe in the expanded state with the reversing excavation wing. While transmitting and rotating, at the same time, the solidified material is discharged from the spout of the auger head, excavated, agitated and fed, and a hollow pipe is buried in this soil cement column while forming the soil cement column, The process of feeding to the specified depth, and when the specified depth is reached, the solidified material is switched to solidified material that has a higher compressive strength after solidification than the solidified material that has been injected up to that time, and the root solidified part at the bottom of the drill hole is solidified. A filling step, and then pulling up the auger rod with the hollow tube fixed to shear the shear pin of the reversing excavating wing to close the reversing excavating wing and insert the auger head into the hollow tube. Process and then the hollow tube 3. The structure according to claim 1, further comprising a step of inserting the auger into the female part and pulling up the auger, and a structure according to claim 2, wherein the hollow tube used in the step has a projection on the inner surface at the lower end. An auger head is provided below the auger rod inserted into a hollow pipe such as a steel pipe pile or a concrete pile, and the hollow pipe and the auger head are rotated and advanced to excavate, and a solidified material is ejected from a spout of the auger head. In a soil cement composite pile forming apparatus for forming a soil cement column by stirring the excavated soil and forming a soil cement column, a hollow pipe is buried in the soil cement column to form a soil cement composite pile. Wherein the auger head comprises: an excavating wing having an outer diameter smaller than the inner diameter of the hollow pipe provided at the tip of the auger rod; and an ejection port for solidified material provided on the auger rod near the excavating wing. And a reversing excavation blade rotatably provided above the excavation wing. The reversing excavation wing is pivotally attached to a support member rotatably and loosely fitted on an auger rod by a pivot, and is sheared after completion of excavation and stirring. It is held in the expanded state by the fixing shear pin, and the outer diameter of the expanded state is at least substantially the same as the outer diameter of the hollow tube, and engages with the transmission member of the hollow tube in the expanded state to rotate. The structure according to claim 3, wherein the auger rod below the excavator wing is provided with a leading excavator wing smaller in diameter than the excavator wing, and the lower end of the auger rod is conical and the conical portion has an outer diameter. 6. The configuration according to claim 5, wherein a spiral excavation wing having a diameter substantially equal to the outer diameter of the auger rod is provided, and at least one stabilizer whose outer diameter is in sliding contact with the inside of the hollow tube is rotatably provided on the auger rod. According to a sixth aspect of the present invention,

[0008]

[Action] An auger rod provided with an auger head at the bottom is inserted into a hollow pipe such as a steel pipe pile, a concrete pile, etc., and the hollow pipe and the auger head are rotated and fed, excavated, and solidified from the spout of the auger head. A hollow pipe is buried in this soil-cement column while forming a soil-cement column by mixing the excavated soil with the excavated soil, and a soil-cement composite pile can be created.

[0009] In the soil cement composite pile forming apparatus, first, the excavator is excavated by a drilling wing, then excavated to a predetermined diameter by a reversing excavating wing, and mixed and stirred with a solidified material ejected from an ejection port. The reversing excavation wing engages with the transmission member of the hollow tube in the expanded state, and the rotation of the hollow tube is transmitted to rotate. This rotation is opposite to the rotation of the auger rod and the digging wing, and works for digging, agitation, and rotation prevention.

[0010] During the excavation and stirring, the reversing excavation wing is fixed to the support member in an expanded state by the shear pin. After the excavation and stirring is completed, the reversing excavation wing is contracted by shearing the shear pin and passes through the hollow pipe. Can be recovered on the ground.

Also, the lower end of the auger rod is made conical,
Even if the outer diameter of the auger rod is approximately the same as that of the auger rod in the conical part, even if there is a hard intermediate layer, excavation and agitation can be performed and soil cement columns can be penetrated and supported. By excavating and agitating the layer, a soil cement composite pile embedded in the supporting layer can be constructed.

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 center deviation of the hollow tube during excavation can be prevented and the auger rod can be prevented from bending. In addition, if the stabilizer is freely rotatably fitted to the auger rod, the vertical movement of the auger rod in the hollow tube becomes easy.

[0013]

Embodiment 1 The present invention will be described below in detail with reference to the illustrated embodiment. FIG. 1 is a front view showing an embodiment of a soil cement composite pile forming apparatus according to 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, a concrete pile, etc. At predetermined intervals above the tip (lower end) side, leading digging wings 3, digging wings 4, reverse digging wings 5 and agitating wings 9 are provided, and the auger rod 2 near the digging wings 4 is provided with cement milk or the like. An auger head 20 is provided by providing an ejection port 10 for the solidified material. The jet 10 of the solidified material may be provided on the auger rod 2 near the preceding excavation wing 3. Then, the solidified material can be ejected to the entire excavation area, and a uniform soil cement column can be formed over the entire length. When two jet ports are provided, it is also possible to make one blind and use only one jet port.

A transmission member 11 protrudes from the outer peripheral edge of the lower end of the hollow tube 1 as shown in FIG. This transmission member 11
Engages with the reverse drilling wing 5 to transmit the rotation of the hollow tube 1 to the reverse drilling wing 5 to rotate the reverse drilling wing 5. Further, the transmission member 11 is fixed to the inner peripheral edge of the hollow tube 1 as shown in FIG. 3, or the protrusion 11a is formed at the lower end of the hollow tube 1 as shown in FIG. Chip 11
b processing may be performed.

The preceding excavator blade 3 is configured such that its excavation diameter is smaller than the excavation diameter of the excavator blade 4. For example, drilling wing 4
The excavation diameter of the preceding excavation wing 3 is 50
It seems to be set to 0 mm. The preceding excavation wing 3 may be mounted in a horizontal direction, and may be arbitrarily set in a direction parallel to or perpendicular to the excavation wing 4. The outer diameter of the excavator blade 4 and the stirring blade 9 is smaller than the inner diameter of the hollow tube 1. Here, the reason why the diameter is smaller than the inner diameter of the hollow tube 1 is to allow the auger head 20 to pass when the auger head 20 is withdrawn upward through the hollow tube 1.

The reversing excavation wing 5 is pivotally mounted on a support member 6 rotatably and loosely fitted on the auger rod 2 by a pivot 7 and is held in an expanded state (horizontal position state) by a shear pin 8 to be in an expanded state. And has substantially the same outer diameter as the hollow tube 1. The reverse excavation wing 5 is provided with a transmission member 11 of the hollow pipe 1.
, The rotation of the hollow tube 1 is transmitted, and the preceding excavator blade 3, the excavator blade 4, and the agitating blade 9 rotate in the opposite direction, thereby excavating and also performing the co-rotation preventing and agitating functions. In addition, the reason why the reversing excavation wing 5 is held in the expanded state (horizontal position state) by the shear pin 8 is to perform excavation, agitation, and prevention of co-rotation in the expanded state.
This is because the shear pin 8 is sheared to rotate and retract about the pivot 7 as shown by a chain line in FIG. 1 so that the shear pin 8 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 reverse excavation blade 5 of the shear pin 8 is engaged with the lower end of the hollow tube 1 and sheared. Accordingly, the shear pin 8 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 lower end (tip) of the auger rod 2 is formed in a conical shape so that the hard intermediate layer and the hard support layer can be reliably excavated and stirred. A spiral drilling wing 13 having substantially the same outer diameter as the rod 2 may be provided. Further, a stabilizer 14 is freely rotatably fitted in the middle of the auger rod 2. The stabilizer 14 is set so that the outer diameter thereof is in sliding contact with the inside of the hollow pipe 1, and prevents the core of the hollow pipe 1 from being misaligned during excavation and the bending of the auger rod 2. Further, the loose fitting prevents the hollow tube 1 and the auger rod 2 from engaging with each other at the time of construction, and facilitates lifting after excavation.

[0018]

Embodiment 2 Next, a method of forming a soil cement composite pile using the above-described soil cement composite pile forming apparatus is shown in FIG.
10 to FIG. 10, a device that applies a rotational force and a feeding force to the hollow tube 1 and the auger rod 2 to rotate and feed the hollow tube 1 and the auger head 20 is known, and thus the description is omitted. . First, as shown in FIG. 6, an auger rod 2 provided with an auger head 20 at a predetermined position on the ground.
A well-known working machine (not shown) for vertically positioning the hollow tube 1 inserted and having the hollow tube 1 inserted therein and rotating and feeding the hollow tube 1
Then, the upper ends of the hollow tube 1 and the auger rod 2 are gripped.

Next, as shown in FIG. 7, while the solidified material such as cement milk is jetted into the ground from the jet port 10 of the auger rod 2, the hollow pipe 1 and the auger rod 2 are blown by a working machine (not shown). As the soil of the ground and the solidified material are forcibly excavated and agitated by the rotating auger head 20, the soil cement having an outer diameter substantially equal to or slightly larger than the outer diameter of the hollow pipe 1 is rotated. The hollow tube 1 is buried in the soil cement column 15 while the column 15 is being formed. The hollow tube 1
The rotation of the auger rod 2 and the rotation of the auger rod 2 are preferably opposite to each other. At this time, the ground is firstly excavated by the rotary excavation leading wing 3, excavated to a larger diameter by the next rotationally advanced excavation wing 4, and further excavated to the predetermined diameter by the next reverse excavation wing 5. The excavated soil is forcibly shredded between the rotating excavating wing 4 and the stirring wing 9 and the counter-rotating reversing excavating wing 5, and co-rotation of the soil is also prevented by the reversing excavating wing 5, and the spout The solidified material spouted from 10 is thoroughly mixed with stirring to form a uniform soil cement column 15. In particular,
The reversing excavation blade 5 engages with the transmission member 11 of the rotating hollow tube 1 and rotates in the reverse direction with the excavation blade 4 and the stirring blade 9, so that the excavated soil is more finely shredded, and the solidified material is further reduced. Because of good stirring and mixing, a more uniform soil cement column 15 is created over the entire length.

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. 8, and the compressive strength after solidification is switched to a solidified material larger than the solidified material injected up to that time to cut. Fill the bottom of the hole with the solidifying material and fix the root
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 15a is such that when drilling to a depth shallower than the predetermined depth by the distance of the root consolidation part 15a at the bottom of the hole, the compressive strength after solidification is greater 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 15a. At this time, it is desirable to provide a projection on the inner surface of the hollow tube 1 in order to increase the adhesive force with the solidified material having high compressive strength after solidification. The protrusion may be welded to the ring streak 1a as shown in FIG. 1, or a steel pipe with an inner rib may be used.

Next, when the hole is drilled to a predetermined depth and the hollow tube 1 reaches the predetermined depth, as shown in FIG. 9, a means 16 for temporarily fixing the hollow tube 1 is pressed downward by a hydraulic jack, for example. And auger rod 2 is pulled up and fixed with a hydraulic chuck or the like, and auger rod 2 is pulled up. Then, the inverted excavation wing 5 held in the expanded state by the shear pin 8 collides with the lower end portion of the hollow tube 1 and is sheared down, so that it is folded downward and contracts, and passes through the hollow tube 1. Withdraw and retreat to the ground. Then, as shown in FIG. 10, the hollow pipe 1 is inserted into the solidified portion 15 a into which the solidifying material having a high compressive strength after solidification is injected, and the soil cement composite pile 17 is completed. In constructing the soil cement composite pile 17, a stabilizer 1 is used.
When the tube 4 is provided, misalignment of the core of the hollow tube 1 and bending of the auger rod 2 are prevented, and the vertical tube is reliably maintained and formed.

[0022]

As described above, according to the present invention, an auger rod provided with an auger head at a lower portion is inserted into a hollow pipe such as a steel pipe pile or a concrete pile to rotate and advance the hollow pipe and the auger head. In addition, excavation and solidification material are spouted from the spout of the auger head, and the excavated soil is stirred with the excavated soil to form a soil cement column, and a hollow pipe is buried in the soil cement column to form a soil cement composite pile. In addition, the rotation of the hollow tube is transmitted by engaging the reverse rotating excavator blade constituting the auger head with the transmission member of the hollow tube, and the reverse excavator blade rotates in the reverse direction to the preceding excavator blade, the excavator blade and the stirring blade, and excavates. In addition, the excavated soil is finely crushed, and the extruded solidified material is further uniformly agitated and mixed, so that a uniform soil cement column can be formed. In addition, the inverted excavation wing is held in an expanded state (horizontal position state) by the shear pin during the excavation and agitation, and after the excavation and agitation, the auger head can be folded and retracted by shearing the shear pin. Can be withdrawn through the ground. Therefore, a highly reliable soil cement composite pile having a high bearing capacity can be reliably and easily constructed without noise and vibration.

In addition, below the reversing excavation wing, there is provided a digging wing having an excavation diameter smaller than that of the reversing excavation wing, and further below the preceding excavation wing having an excavation diameter smaller than the excavation wing. Excavation is performed with a small leading excavator, followed by excavation with the excavator, and subsequently excavation to a predetermined diameter with the reverse excavator. For this reason, the excavating speed is increased, the current consumption of the auger motor is small, and 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. Since the projections are provided on the inner side surface of the hollow tube tip, the adhesion with the solidified material is strengthened, and the vertical supporting force acting on the composite pile can be reliably transmitted to the supporting ground. Furthermore, since the stabilizer is provided in the middle of the auger rod, the runout of the hollow tube and the bending of the auger rod are prevented, and the verticality is reliably maintained, so that the soil cement composite pile is formed. Furthermore, according to the present invention, since the gap between the outside of the pile and the ground is filled with soil cement, the adhesive force between the pile and the ground is reliably exerted, and the thickness of the soil cement layer between the pile and the ground is ensured. In the case of the present invention, the amount of excavation and the amount of cement during construction are small and economical.

[Brief description of the drawings]

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

FIG. 2 is a partial perspective view of a hollow tube showing a transmission member of the present invention.

FIG. 3 is a partial perspective view of a hollow tube showing a transmission member of the present invention.

FIG. 4 is a partial perspective view of a hollow tube showing a transmission member of the present invention.

FIG. 5 is a partial perspective view of a hollow tube showing a transmission member of the present invention.

FIG. 6 is a process diagram showing the order of forming the soil cement composite pile of the present invention.

FIG. 7 is a next process diagram showing the construction order of the soil cement composite pile of the present invention.

FIG. 8 is a next process diagram showing the construction order of the soil cement composite pile of the present invention.

FIG. 9 is a next process diagram showing the construction order of the soil cement composite pile of the present invention.

FIG. 10 is a next process diagram showing the construction order of the soil cement composite pile of the present invention.

FIG. 11 is a front view showing a conventional example.

FIG. 12 is a front view showing a use state of a conventional example.

FIG. 13 is a front view showing another conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 hollow tube 2 auger rod 3 leading drilling wing 4 drilling wing 5 reverse drilling wing 6 support member 7 pivot 8 sharpening 9 stirring blade 10 jetting port 11 transmission member 11a transmission member 11b transmission member 13 spiral drilling blade 14 stabilizer 15 soil cement Pillar 20 Auger Head

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Claims (6)

(57) [Claims] 1. A method for forming a soil cement composite pile comprising the following steps. (1) The auger head is provided at the tip of the auger rod,
A drilling wing having an outer diameter smaller than the inner diameter of a hollow pipe such as a steel pipe pile or a concrete pile, an injection port of solidified material such as cement milk provided on an auger rod near the drilling wing, and a rotatable upper part of the drilling wing. A reverse drilling wing that is provided and engages the lower end of the hollow pipe. The reverse drilling wing has an outer diameter in an expanded state at least substantially the same as the outer diameter of the hollow pipe, and is rotatable on an auger rod. A steel pipe pile, a concrete pile, which is pivotally attached to the loosely fitted support member by a pivot and is held in an expanded state by a fixing shear pin which is sheared after the end of excavation and stirring, and has the auger head having a transmission member at a lower end thereof; And a step of inserting the auger head ahead of the hollow tube. (2) The upper end of the auger rod and the hollow tube are gripped by the working machine, respectively, and the auger rod and the hollow tube are rotated in opposite directions to each other, and the reversing excavation wing is also expanded through the transmission member of the hollow tube. While transmitting and rotating the rotation of the hollow tube, at the same time, the solidified material is discharged from the spout of the auger head, excavated, agitated, and fed to form a soil cement column. A process of burying pipes and feeding them to a predetermined depth in the ground. (3) a step of, when a predetermined depth is reached, switching the injection of the solidified material to a solidified material having a higher compressive strength after solidification than the solidified material that has been injected so far, and filling the solidified material at the bottom of the drill hole with the solidified material. (4) Next, a step of pulling up the auger rod with the hollow pipe fixed, shearing the shear pin of the reverse drilling wing to close and close the reverse drilling wing, and inserting the auger head into the hollow pipe. (5) Next, a step of inserting a hollow tube into the root consolidation portion and lifting the auger. 2. The method for forming a soil cement composite pile according to claim 1, wherein the hollow pipe has a projection on the inner surface at the lower end. 3. An auger head is provided at a lower portion of an auger rod inserted into a hollow pipe such as a steel pipe pile or a concrete pile, and the hollow pipe and the auger head are rotated and fed to excavate and solidify from the spout of the auger head. In a soil-cement composite pile forming apparatus for forming a soil-cement column by agitating the excavated soil and forming a soil-cement column, a hollow pipe is buried in the soil-cement column to form a soil-cement composite pile. A transmission member is provided on a peripheral edge, and the auger head includes an excavating wing having an outer diameter smaller than the inner diameter of a hollow pipe provided at the tip of the auger rod, and a spout of a solidified material provided on the auger rod near the excavating wing. And an inverted excavation wing rotatably provided above the excavation wing, and the inverted excavation wing is pivotally attached to a support member rotatably and loosely fitted to the auger rod by a pivot to complete excavation and stirring. It is held in an expanded state by a fixing shear pin which is later sheared, and the outer diameter of the expanded state is at least substantially the same as the outer diameter of the hollow tube, and is engaged with the transmission member of the hollow tube in the expanded state. A soil cement composite pile forming device characterized in that it rotates together. 4. The soil cement composite pile forming apparatus according to claim 3, wherein a leading excavator blade smaller in diameter than the excavator blade is provided on the auger rod below the excavator blade. 5. The auger rod according to claim 3, wherein a lower end of the auger rod is formed in a conical shape, and a spiral excavation wing having a diameter substantially equal to the outer diameter of the auger rod is provided in the conical portion.
Or the soil cement composite pile creation device according to claim 4. 6. The soil cement composition according to claim 3, wherein at least one stabilizer whose outer diameter is in sliding contact with the inside of the hollow tube is rotatably provided on the auger rod. Pile creation device.