JPH04289319A - Method and apparatus for forming soil cement composite pile - Google Patents

Abstract

PURPOSE:To easily and exactly attain construction work by using an auger head provided to the tip of an auger rod, consisting of an excavation blade whose outside diameter is smaller than the inside diameter of a hollow tube, a jet port for a hardener, and a reversely turning excavation blade to be coupled with the lower end of the hollow tube. CONSTITUTION:An auger rod 2 is inserted into a hollow tube 1 under a condition that an auger head 20 is precedently set, and the upper ends of the rod 2 and the tube 1 are coupled to each operating machine. The rod 2 and the tube 1 are turned mutually to opposite directions, the reversely turning excavation blade 5 is opened and turned with the rotation of the tube 1, and a hardener is discharged from a jet port 10. The ground is excavated to a given depth while being stirred. The hardener is then switched to a hardener having a greater compressive strength to form the foot-protected portion 15a of the pit bottom. The tube 1 is fixed, and the rod 2 is pulled up. The blade 5 is closed to remove it to the ground's surface, and the tube 1 is penetrated into the portion 15a to make up a soil cement composite pile 17, The construction work can thus be easily attained by uniform mixing without co-rotation of these parts.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for constructing soil-cement composite piles that are applied to construction-related foundation work.

0002

2. Description of the Related Art Conventionally, as a method for constructing soil-cement composite piles, an auger for constructing soil-cement composite piles has been proposed as shown in Japanese Patent Application No. 2-7064. As shown in FIG. 11, this auger for soil cement synthetic pile construction has a movable blade support member 35 fixed to an auger support shaft 33 connected to the lower part of an auger rod 32 in a hollow tube 31. 35, the proximal end of the auger movable blade 34 is pivoted by a pivot 36, and the auger movable blade 34 is in an expanded state (horizontal position state) in which the distal end side of the auger movable blade 34 protrudes beyond the outer surface of the hollow tube 31, The shear pin 37 for fixing the auger movable blade, which is cut after the completion of excavation and agitation, is attached to the auger movable blade support member 35.
and the auger movable blade 34, forming an auger head 40. In the figure, 38 is a discharge port for solidifying material such as cement milk, and 39 is an auger support shaft 3.
This is a screw head provided at the tip of No. 3.

According to this auger for constructing soil cement synthetic piles, during excavation and agitation, the auger movable blade 34 is fixed to the movable blade support member 35 in the expanded state by the shear pin 37, and after the excavation and agitation is completed, the As shown in 12, by cutting the shear pin 37, the auger movable blade 34 is retracted and closed, and the auger head 40 can be recovered on the ground through the hollow tube 31. Not only can the soil cement pillar 41 of the outer diameter be reliably created, but also the hollow tube 31 can be buried in the soil cement pillar with high precision while creating the soil cement pillar.

[0004] However, in the auger for constructing soil-cement synthetic piles, all the movable blades 34 of the auger rotate in the same direction to excavate and stir, so if the ground is cohesive soil, they rotate together and create large clods. This has the disadvantage that the agitation and mixing condition deteriorates and the strength of the soil cement column becomes insufficient.

Therefore, in the same application, as shown in FIG. 13, a support member 35A is rotatably attached to the auger support shaft 33 at a position vertically adjacent to the movable blade support member 35. The proximal end portion of the co-rotation prevention wing 34A is pivotally attached by the pivot 36A, and the co-rotation prevention wing 34
With the tip of A protruding laterally beyond the tip of the auger movable blade 34, the syn-rotation prevention blade fixing shear pin 37A, which is cut after the completion of excavation and agitation, is attached to the support member 35A and the base of the syn-rotation prevention blade 34A. An auger for constructing soil-cement composite piles has been proposed that is inserted through the ends. According to this auger for constructing soil-cement synthetic piles, rotation of the anti-rotation blade 34A is restrained by the ground, so that the rotation of the soil can be prevented.

[0006]

[Problems to be Solved by the Invention] However, since the stirring auxiliary vanes 34A of the conventional soil cement construction auger have a diameter larger than the drilling diameter, they dig into the ground and become stationary, which only prevents co-rotation. Therefore, there are disadvantages in that the shredding and agitation of the clay soil are not sufficient, and since all the movable blades 34 have the same diameter, the excavation load is large, the excavation time is long, and the power consumption is high. there were. In view of these points, it is an object of the present invention to provide a method and apparatus for constructing a soil-cement composite pile that solves the above-mentioned drawbacks.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an auger head that is provided at the tip of an auger rod, and is capable of excavating an outer diameter smaller than the inner diameter of a hollow pipe such as a steel pipe pile or a concrete pile. It consists of a blade, a spout for solidifying material such as cement milk provided on an auger rod near the drilling blade, and a reverse drilling blade that is rotatably provided above the drilling blade and engages with the lower end of the hollow tube. , the reversing excavation blade has an outer diameter at least substantially the same as the outer diameter of the hollow tube in the expanded state, is pivoted to a support member that is rotatably loosely fitted to the auger rod, and is sheared after the excavation agitation is completed. A process of inserting the auger head into a hollow pipe, such as a steel pipe pile or concrete pile, which has a transmission member at its lower end, with the auger head leading the way. Then, the upper ends of the auger rod and the hollow tube are held by the working machine, and the auger rod and the hollow tube are rotated in opposite directions, and the reversing excavation blades are also expanded and rotated through the transmission member of the hollow tube. While transmitting the rotation of the hollow tube and rotating it, at the same time, the solidifying material is discharged from the spout of the auger head, excavated, stirred and fed, forming a soil cement column, and the hollow tube is inserted into the soil cement column. The process involves burying the material and feeding it to a predetermined depth in the ground, and when the predetermined depth is reached, the injection of solidification material is switched to a solidification material that has a higher compressive strength after solidification than the solidification material injected up to that point. The step of filling the foot hardening section with the solidifying material, and then pulling up the auger rod with the hollow tube fixed, shearing the shear pin of the reversing excavation blade, retracting and closing the reversing excavation blade, and removing the auger head. 2. The structure according to claim 1, comprising the steps of: inserting the auger into the foot hardening section; and then inserting the hollow tube into the foot protection section and lifting the auger; and the lower end of the hollow tube used in the step. The structure according to claim 2, characterized in that the part has a projection on the inner surface, and an auger head is provided at the lower part 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 supplied. As the soil cement is advanced and excavated, a solidifying material is ejected from the spout of the auger head and mixed with the excavated soil to form a soil cement column, and a hollow pipe is buried in the soil cement column to create a soil cement composite pile. In the synthetic pile building device, a transmission member is provided at the lower end periphery of the hollow tube, and the auger head includes a digging blade having an outer diameter smaller than the inner diameter of the hollow tube provided at the tip of the auger rod;
It consists of a solidified material spout provided on the auger rod near the excavation blade, and a reversing excavation blade rotatably provided above the excavation blade, and the reversing excavation blade is rotatably loosely fitted to the auger rod. It is held in the expanded state by a fixing shear pin that is pivotally attached to the support member and sheared after the completion of excavation and agitation, and the outer diameter in the expanded state is at least approximately the same as the outer diameter of the hollow tube, and the expanded state is The structure according to claim 3, in which the auger rod engages and rotates with the transmission member of the hollow tube in the open state, and the structure according to claim 4, wherein a leading excavation blade having a smaller diameter than the excavation blade is provided on the auger rod below the excavation blade. The structure of claim 5, wherein the lower end of the auger rod is made into a conical shape, and the conical part is provided with a spiral cutting blade whose outer diameter is approximately the same as the outer diameter of the auger rod, and the outer diameter is a hollow tube. The auger rod is provided with at least one stabilizer rotatably provided on the auger rod so as to be in sliding contact with the inside thereof.

[0008]

[Operation] An auger rod with an auger head at the bottom is inserted into a hollow pipe such as a steel pipe pile or concrete pile, and the hollow pipe and auger head are rotated and fed to excavate and solidify from the spout of the auger head. A soil-cement composite pile can be created by ejecting the material and stirring it with the excavated soil to form a soil-cement column, and then burying a hollow pipe in the soil-cement column.

[0009] In the soil-cement synthetic pile making apparatus, first, excavation is performed using excavation blades, and then excavation is performed to a predetermined diameter using reversing excavation blades, and the soil is mixed and stirred with the solidifying material ejected from the spout. The reversing excavation blade engages with the transmission member of the hollow tube in the expanded state, and rotates as the rotation of the hollow tube is transmitted. This rotation is opposite to the rotation of the auger rod and excavation blade, and functions to excavate, stir, and prevent co-rotation.

During excavation agitation, the reversing excavator blades are fixed to the supporting member in an expanded state by shear pins, and after the excavation agitation is completed, the reversing excavator blades are retracted by shearing the shear pins, and the reversible excavator blades are retracted through the hollow pipe. It can be collected on the ground.

[0011] Furthermore, the lower end of the auger rod is made conical,
If the conical part is provided with a spiral excavation blade whose outer diameter is similar to the outer diameter of the auger rod, even if there is a hard intermediate layer, it can be excavated and agitated to penetrate the soil cement column, and it can also provide support. By excavating and stirring the layer, it is possible to construct soil-cement composite piles that are rooted in the supporting layer.

[0012] When the auger rod is provided with a stabilizer whose outer diameter slides on the inside of the hollow tube, it is possible to prevent the hollow tube from being misaligned during excavation and to prevent the auger rod from bending. Further, if the stabilizer is rotatably loosely fitted to the auger rod, the auger rod can be easily moved in the vertical direction within the hollow tube.

[0013]

Embodiment 1 The present invention will be explained in detail below with reference to the illustrated embodiments. FIG. 1 is a front view showing an embodiment of the soil-cement composite pile construction apparatus according to the present invention. At the bottom of an auger rod 2 placed at the center of a hollow pipe 1 such as a vertical steel pipe pile or concrete pile, Advance drilling blades 3, drilling blades 4, reverse drilling blades 5, and stirring blades 9 are provided at predetermined intervals above the tip (lower end) side, and the auger rod 2 near the drilling blades 4 is filled with cement milk or the like. An auger head 20 is provided with a spout 10 for solidifying material. The solidifying material spout 10 may be provided in the auger rod 2 near the advance excavation blade 3. In this way, the solidifying material can be sprayed over the entire excavated area, forming a soil cement column that is uniform over the entire length. When two spouts are provided, it is also possible to make one blind and use only one spout.

A transmission member 11 is provided protruding from the outer peripheral edge of the lower end of the hollow tube 1, as shown in FIG. The transmission member 11 engages with the reversing excavation blade 5, transmits the rotation of the hollow tube 1 to the reversing excavation blade 5, and rotates the reversal excavation blade 5. Alternatively, the transmission member 11 may be fixed to the inner peripheral edge of the hollow tube 1 as shown in FIG. 3, a protrusion 11a may be formed on the lower end of the hollow tube 1 as shown in FIG. It is also possible to process the notch 11b.

The preceding excavation blade 3 is constructed so that its excavation diameter is smaller than that of the excavation blade 4. For example, drilling wing 4
For the excavation diameter of 1000 mm, the excavation diameter of the preceding excavation blade 3 is 5
It is like setting it to 00mm. The preceding excavation blade 3 may be attached in any direction as long as it is horizontal, and may be parallel to or perpendicular to the excavation blade 4. Further, the outer diameters of the excavating blades 4 and stirring blades 9 are smaller than the inner diameter of the hollow tube 1. The reason why the diameter is made smaller than the inner diameter of the hollow tube 1 is to allow the auger head 20 to pass through the hollow tube 1 when withdrawing upward.

The reversing excavation blade 5 is pivotally connected by a pivot shaft 7 to a support member 6 which is rotatably loosely fitted to the auger rod 2, and is held in an expanded state (horizontal position state) by a shear pin 8. The outer diameter of the hollow tube 1 is approximately the same as that of the hollow tube 1. The rotation of the hollow tube 1 is transmitted to the reversing excavation blade 5 by engaging with the transmission member 11 of the hollow tube 1, and the reversing excavation blade 5 rotates in the opposite direction to the preceding excavation blade 3, excavation blade 4, and stirring blade 9, and excavates. At the same time, it also functions to prevent synergism and stir. Further, the reason why the reversing excavation blade 5 is held in the expanded state (horizontal position state) by the shear pin 8 is that the reversing excavation blade 5 is held in the expanded state (horizontal position state).
After stirring and preventing co-rotation, after the excavation and stirring are completed, the shear pin 8 is sheared and rotated and retracted about the axis 7 as shown by the chain line in Fig. 1, passing through the hollow pipe 1 when withdrawing to the ground. This is to make it possible. When the auger head 20 is lifted up together with the auger rod 2, the shear pin 8 is sheared by the reversing cutting blades 5 being locked to the lower end of the hollow tube 1. Therefore, the shear pin 8 is provided with an annular V-groove (not shown) for shearing at the position to be sheared in order to make shearing relatively easy and reliable.

In addition, in order to reliably excavate and stir even the hard intermediate layer and the hard supporting layer, the lower end (tip) of the auger rod 2 is formed into a conical shape, and the outer diameter of the auger rod 12 is formed into a conical shape. A spiral cutting blade 13 having approximately the same outer diameter as the rod 2 may be provided. Furthermore, a stabilizer 14 is loosely fitted in the middle of the auger rod 2 so as to be freely rotatable. The stabilizer 14 is set so that its outer diameter comes into sliding contact with the inside of the hollow tube 1, and prevents the hollow tube 1 from being misaligned during excavation and also prevents the auger rod 2 from bending. In addition, the loose fit prevents the hollow tube 1 and the auger rod 2 from interlocking during construction, and facilitates lifting after the completion of excavation.

[0018]

[Example 2] Next, a method for constructing soil-cement composite piles using the soil-cement composite pile construction device is shown in Fig. 6.
This will be explained with reference to FIGS. 10 to 10, but the device that applies rotational force and feeding force to the hollow tube 1 and the auger rod 2 and rotates and feeds the hollow tube 1 and the auger head 20 is well known, so the explanation will be omitted. . First, as shown in FIG. 6, an auger rod 2 with an auger head 20 provided at the bottom is placed at a predetermined position on the ground.
The hollow tube 1 with the auger rod 2 inserted therethrough is placed vertically, and the upper ends of the hollow tube 1 and the auger rod 2 are gripped by a known working machine (not shown) that rotates and feeds the auger rod.

Next, as shown in FIG. 7, the hollow pipe 1 and the auger rod 2 are spouted out from the spout 10 of the auger rod 2 into the ground using a working machine (not shown) while solidifying material such as cement milk is being spouted into the ground from the spout 10 of the auger rod 2. When it is rotated and fed, the soil and solidification material at the ground are forcibly excavated and stirred by the rotating auger head 20, and soil cement with an outer diameter that is approximately the same as or slightly larger than the outer diameter of the hollow tube 1 is formed. While the pillars 15 are being constructed, the hollow pipes 1 are buried in the soil cement pillars 15. The hollow tube 1
The rotation of the auger rod 2 and the auger rod 2 are preferably in opposite directions. At this time, the ground is first excavated by the advance excavation blade 3 that is rotatably fed, excavated to a larger diameter by the next excavator blade 4 that is rotatably fed, and then excavated to a predetermined diameter by the next reversing excavator blade 5. The excavated soil is forcibly shredded between the rotating excavation blades 4 and stirring blades 9 and the reverse rotation excavation blades 5, and the rotation of the soil is also prevented by the reversal excavation blades 5. It is well stirred and mixed with the solidifying material spouted from 10,
Uniform soil cement pillars 15 are created. In particular, the reversing excavation blades 5 engage with the transmission member 11 of the rotating hollow tube 1 and rotate in the opposite direction to the excavation blades 4 and the stirring blades 9, so that the excavated soil is shredded better and the solidification material The soil cement column 1 is more uniform throughout its length because both are better stirred and mixed.
5 will be created.

When the feeding reaches a predetermined depth, the feeding of the hollow tube 1 and the auger rod 2 is stopped as shown in FIG. The bottom of the hole is filled with the hardening material and the hardening part 15 is formed.
form a. In this case, the auger should not be propelled, but should be rotated. Further, the formation of the foot hardening part 15a is such that when the hole is drilled to a depth shallower than the predetermined depth by the distance of the foot hardening part 15a at the bottom of the hole, the compressive strength after hardening is greater than that of the hardening material injected up to that point. It may be formed by switching to a solidifying material and drilling the hole to a predetermined depth while injecting the solidifying material by the distance of the foot hardening portion 15a. At this time, it is desirable that the hollow tube 1 is provided with protrusions on its inner surface in order to increase the adhesion force with the solidifying material having a high compressive strength after solidifying. The protrusion may be formed by welding a ring striation 1a as shown in FIG. 1, or by using a steel pipe with internal ribs or the like.

Next, when the hole is drilled to a predetermined depth and the hollow tube 1 reaches the predetermined depth, as shown in FIG. or grip it with a hydraulic chuck or the like to fix it, and then pull up the auger rod 2. Then, the reversing excavation blades 5 held in the expanded state by the shear pin 8 collide with the lower end of the hollow tube 1 and the shear pin 8 is sheared, so that it is folded downward and retracted, passing through the inside of the hollow tube 1. Salvage and withdraw to the ground. Then, as shown in FIG. 10, the hollow tube 1 is inserted into the foot hardening section 15a into which a hardening material having a large compressive strength after hardening is injected, and the soil cement composite pile 17 is completed. When constructing this soil cement composite pile 17, stabilizer 1
4 prevents the hollow tube 1 from misaligning and the auger rod 2 from bending, and the verticality is reliably maintained.

[0022]

[Effects of the Invention] As described above, according to the present invention, an auger rod having an auger head at the bottom is inserted into a hollow pipe such as a steel pipe pile or a concrete pile, and the hollow pipe and auger head are rotated and fed. While excavating, a solidification material is ejected from the spout of the auger head and mixed with the excavated soil to form a soil cement column, and a hollow pipe is buried in the soil cement column to create a soil cement composite pile. Moreover, the rotation of the hollow tube is transmitted by the reversing excavation blade that constitutes the auger head, which rotates in the opposite direction to the preceding excavation blade, excavation blade, and stirring blade by engaging with the transmission member of the hollow tube, and excavates. Since stirring and co-rotation prevention are also performed at the same time, the excavated soil is more finely pulverized, and the discharged solidification material is more uniformly stirred and mixed, making it possible to create a uniform soil-cement column. In addition, the reversing excavation blades are held in the expanded state (horizontal position) by shear pins during excavation agitation, and after the excavation agitation is completed, they can be folded and retracted by shearing the shear pins, so that the auger head can be placed inside the hollow tube. It can be withdrawn to the ground through the Therefore, highly reliable soil-cement composite piles with high bearing capacity can be constructed reliably and easily without noise or vibration.

[0023] Further, below the reversing excavating blade, there is provided an excavating blade with a smaller excavating diameter than that of the reversing excavating blade, and further below that there is provided a leading excavating blade with an excavating diameter smaller than that of the reversing excavating blade. Excavation is carried out with a small advance excavation blade, followed by excavation with an excavation impeller, and then excavation to a predetermined diameter with a reversing excavation impeller. For this reason, effects such as faster digging speed, lower current consumption of the auger motor, and lower current/speed ratio are achieved. Furthermore, the lower end (tip) of the auger rod is formed into a conical shape, and this conical part is provided with spiral cutting blades whose outer diameter is approximately the same as the auger rod, even if the outer diameter is large. It is possible to reliably excavate and stir even layers and hard supporting layers, and it is possible to reliably create soil-cement composite piles that are embedded in the supporting layers. Since a protrusion is provided on the inner surface of the tip of the hollow tube, the adhesion with the solidifying material is strong, and the vertical supporting force acting on the synthetic pile can be reliably transmitted to the supporting ground. Furthermore, since a stabilizer is provided in the middle of the auger rod, the core runout of the hollow tube and the bending of the auger rod are prevented, and verticality is reliably maintained to create a soil cement composite pile. Furthermore, according to the present invention, the gap between the outside of the pile and the ground is filled with soil cement, so the adhesion between the pile and the ground is reliably exerted, and the thickness of the soil cement layer between the pile and the ground is reduced. In the case of the present invention, since the diameter is smaller than that of the conventional method, the amount of excavation and cement required during construction is small, making it economical.

[Brief explanation of the drawing]

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

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

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

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

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

FIG. 6 is a one-step diagram showing the order of construction of the soil-cement composite pile of the present invention.

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

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

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

FIG. 10 is a next step diagram showing the order of construction 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 the state of use of the conventional example.

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

[Explanation of symbols]

1 Hollow tube 2 Ogarod 3 Advance drilling wing 4 Drilling wing 5　Reverse drilling blade 6 Support member 7 Axis 8 Sharpin 9 Stirring blade 10　Spout port 11 Transmission member 11a Transmission member 11b Transmission member 13 Spiral drilling blade 14 Stabilizer 15 Soil cement pillar 20 Ogre head

Claims (6)

[Claims] [Claim 1] A method for constructing a soil-cement composite pile comprising the following steps. (1) The auger head is installed at the tip of the auger rod, and has an excavation wing with an outer diameter smaller than the inner diameter of a hollow pipe such as a steel pipe pile or concrete pile, and a cement milk etc. It consists of a solidification material spout and a reversing excavator blade that is rotatably provided above the excavator blade and engages the lower end of the hollow tube, and the reversible excavator blade has an outer diameter at least hollow when expanded. The support member has approximately the same outer diameter as the tube and is rotatably loosely fitted to the auger rod, and is pivotally connected to the support member.
The auger head is held in an expanded state by fixing shear pins that are sheared after the completion of excavation and stirring, and the auger head is placed in front of a hollow pipe such as a steel pipe pile or concrete pile that has a transmission member at its lower end. The process of inserting it in the state. (2) The upper ends of the auger rod and the hollow tube are each held by a working machine, and the auger rod and the hollow tube are rotated in opposite directions, and the reversing excavation blades are also expanded through the transmission member of the hollow tube. While rotating the hollow tube by transmitting the rotation, at the same time, the solidified material is discharged from the spout of the auger head, excavating,
The process of stirring and feeding, forming a soil cement column, burying a hollow tube in the soil cement column, and feeding it to a predetermined depth in the ground. (3) When a predetermined depth is reached, the injection of solidification material is switched to a solidification material that has a higher compressive strength after solidification than the solidification material injected up to that point, and the foot hardening section at the bottom of the borehole is filled with the solidification material. (4) Next, the step of pulling up the auger rod with the hollow tube fixed, shearing the shear pin of the reversing excavation blade to retract and close the reversing excavation blade, and inserting the auger head into the hollow tube. (5) Next, a step of inserting a hollow tube into the foot hardening section and pulling up the auger. 2. The method for constructing a soil cement composite pile according to claim 1, wherein the hollow tube has a protrusion on the inner surface of the lower end. [Claim 3] An auger head is provided at the bottom of an auger rod inserted into a hollow pipe such as a steel pipe pile or a concrete pile,
The hollow tube and auger head are rotated and fed, and while excavating, the solidifying material is ejected from the spout of the auger head and mixed with the excavated soil to form a soil cement column, and the hollow tube is inserted into the soil cement column. In a soil-cement composite pile construction device for constructing buried soil-cement composite piles, a transmission member is provided at the lower end periphery of the hollow tube, and the auger head is connected to the inner diameter of the hollow tube provided at the tip of the auger rod. It consists of a drilling blade with a small outer diameter, a solidification material spout provided on an auger rod near the drilling blade, and a reverse drilling blade rotatably installed above the drilling blade. It is held in an expanded state by a fixing shear pin that is sheared after the completion of excavation and agitation, and the outer diameter of the expanded state is at least as large as the outer diameter of the hollow tube. A soil cement synthetic pile construction device characterized in that the diameter is substantially the same as that of the hollow tube, and that the hollow tube rotates by engaging with the transmission member of the hollow tube in an expanded state. 4. The soil cement composite pile construction apparatus according to claim 3, wherein the auger rod below the excavation blade is provided with a leading excavation blade having a smaller diameter than the excavation blade. 5. The lower end of the auger rod is formed into a conical shape, and the conical portion is provided with a spiral cutting blade whose outer diameter is approximately the same as the outer diameter of the auger rod. Item 4. Soil-cement composite pile construction device. 6. Claim 3, claim 4, or claim 5, characterized in that the auger rod is rotatably provided with at least one stabilizer whose outer diameter is in sliding contact with the inside of the hollow tube.
The soil-cement composite pile construction equipment described above.