JPH0813473A - Boring rod for soil improvement and soil improvement method - Google Patents

Abstract

PURPOSE:To construct a reliable and stable underground preparation pile in which the excavated soil is solidified uniformly, by evenly and securely mixing the excavated soil with a curing material of soil. CONSTITUTION:Excavation blades 2 are horizontally protruded at the front end of a hollow shaft and a rotary brade shaft 6 provided with vertical agitating blades 3 at the outer periphery of the upper front end is horizontally protruded so as to be rotatable around the axial line. And further, horizontal agitation blades 4 are horizontally protruded at the outer periphery of the front end and a delivery outlet 5 of a ground solidifying agent is opened near the front end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement boring rod and ground for drilling the ground to mix excavated soil and ground hardened material and solidify the excavated soil to construct an underground pile. It concerns an improved construction method.

[0002]

2. Description of the Related Art Conventionally, a leader is attached to a crawler, and a boring rod is attached to the crawler so that the boring rod can be freely moved up and down along the leader by rotating the boring rod. After drilling the ground, the ground hardening material pumped into the boring rod is jetted from the discharge port into the drilling earth and sand, and the rod is pulled up while rotating and the stirring blades provided on the outer circumference of the drilling earth and sand A ground improvement method is being implemented in which the ground hardening material is agitated to form a solidified soil column in the ground to improve the ground.

[0003]

SUMMARY OF THE INVENTION In the above conventional method,
While rotating the boring rod and pulling it up, the stirring blades provided on the outer periphery are simply swung horizontally to stir the soil laterally.Therefore, the sand and the ground hardening material are not agitated closely and partially Agitation or a part with insufficient agitation occurs,
As a result, there was a problem that the solidification of the soil was non-uniform due to the non-uniform agitation and an unsolidified portion was generated, so that the stable strength of the aggregated soil column could not be obtained and the durability was poor.

[0004]

In order to solve the above-mentioned conventional problems, the present invention provides a hollow shaft with a digging blade 2 projecting laterally at the tip thereof, and a vertical stirring blade 3 around the periphery of the tip portion above the digging blade 2. A rotary impeller shaft 6 which is provided so as to be rotationally driven around its axis, and laterally agitating blades 4 are laterally projected at the outer periphery of the tip end portion, and a ground hardening material discharge port 5 is provided near the tip end portion. This is to propose a ground improvement boring rod provided with.

Further, according to the present invention, the excavation blade 2 is provided at the tip of the hollow shaft.
Is horizontally projected, and a rotor blade shaft 6 provided with a vertical stirring blade 3 on the outer periphery of the tip portion above it is horizontally projected so as to be rotatable about its axis, and further laterally stirred on the outer periphery of the tip portion. The blades 4 are projected laterally, a ground hardening material discharge port 5 is provided near the tip, and the vertical stirring blades 3 are respectively attached to a plurality of horizontal rotary blade shafts 6, and each rotary blade shaft 6 is boring. Rod 1
A cylindrical shaft 7 having a small diameter provided in the vicinity of the tip end of the rotary shaft 6 rotatably mounted on the outer periphery of an annular body 8 rotatably mounted about this shaft. A bevel gear 9 is attached to the base end, and a bevel gear 9 for ground improvement is proposed in which a bevel gear 10 attached to a cylinder shaft 7 meshes with the bevel gear 9.

Further, according to the present invention, the excavating blade 2 is attached to the tip of the outer pipe 13 which is a hollow double pipe in which the inner and outer pipes 12 and 13 are independently rotatable.
A laterally protruding portion, and a rotor blade shaft 6 provided with a vertical stirring blade 3 around the outer periphery of the outer pipe 13 above the outer tubular portion 13 so as to be rotationally driven around its axial center. A horizontal stirring blade 4 is laterally projected on the outer periphery of the tip portion of 13, a ground hardening material discharge port 5 is provided in the vicinity of the tip portion, and a bevel gear 10 is attached to the tip portion of the inner pipe 12, and the outer pipe 13 is attached to this. A boring rod for ground improvement is proposed in which a bevel gear 9 of a rotary blade shaft 6 protruding from the meshes with each other.

Further, according to the present invention, the excavation blade 2 is provided at the tip of the hollow shaft.
Is horizontally projected, and a rotor blade shaft 6 provided with a vertical stirring blade 3 on the outer periphery of the tip portion above it is horizontally projected so as to be rotatable about its axis, and further laterally stirred on the outer periphery of the tip portion. While rotating the boring rod 1 having the blade 4 projecting laterally and providing the ground hardening material discharge port 5 in the vicinity of the tip, while rotating the vertical stirring blade 3 around the axis together with the rotary blade shaft 6. By excavating by press-fitting into the ground and pumping the ground hardening material into the boring rod 1 at the time of its rotary excavation and injecting it into the excavated soil from the discharge port 5, the excavating blade 2, the vertical stirring blade 3, and the horizontal stirring blade 4 mixes the excavated soil and the ground hardening material vertically and horizontally, and after excavating to the design depth, the boring rod 1 is rotated, and the vertical stirring blade 3 is rotated around the shaft center together with the rotating blade shaft 6, and the drilling is performed. Ground to solidify soil and construct underground piles It is intended to propose an improved method.

Further, according to the present invention, the excavating blade 2 is laterally projected at the tip of the hollow shaft, and the rotary blade shaft 6 provided with the vertical stirring blade 3 on the periphery of the upper tip is rotated about its axis. Driven laterally, and a horizontal stirring blade 4 on the outer periphery of the tip.
Is projected laterally, and the discharge port 5 for the ground hardening material is provided near the tip.
While rotating the boring rod 1 provided with, the vertical stirring blade 3 is rotated together with the rotary blade shaft 6 around its axis, the boring rod 1 is rotated after press-fitting into the ground and excavating to the design depth. Together with the rotary blade shaft 6, the vertical stirring blade 3 is pulled up while rotating around its axis, and at the same time, the ground hardening material is pressure-fed into the boring rod 1 and injected into the excavated soil from the discharge port 5 to excavate. This is to propose a ground improvement method in which excavated soil and ground hardening material are mixed vertically and horizontally by the blades 2, the vertical stirring blades 3, and the horizontal stirring blades 4, and the excavated soil is solidified to construct an underground pile.

[0009]

[Operation] As the boring rod 1 rotates, the rotary blade shaft 6
The earth excavated by the excavating blade 2 is rotationally stirred in the vertical direction by the rotation of the vertical rotating blade 3 by rotating the vertical rotating blade 3 about its axis and rotating the vertical stirring blade 3 around this axis. As a result, the soil is uniformly and reliably stirred in the vertical and horizontal directions together with the horizontal stirring blades 4 that swirl in the horizontal plane to stir.

Therefore, when the boring rod 1 is rotationally excavated or when the boring rod 1 is pulled up while rotating after being dug to the designed depth, the ground hardening material such as cement milk is pressure-fed into the boring rod 1 to discharge it. By injecting into the excavated soil from 5,
The excavating blade 2, the vertical stirring blade 3, and the horizontal stirring blade 4 uniformly and reliably stir and mix the excavated soil and the ground hardening material in the vertical and horizontal directions.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a boring rod 1 made of a hollow shaft is provided with a bit-bearing excavation blade 2 which is laterally projected and fixed around the tip end portion thereof, and is provided above it so as to be rotatable around a horizontal axis. A vertical stirring blade 3 and a horizontal stirring blade 4 projecting and fixed laterally on the outer circumference of the rod are provided, and a ground hardening material discharge port 5 is provided at a required position near the rod tip, such as around the rod tip or around the excavation blade. ing.

The vertical stirring blades 3 are attached to a plurality of horizontal rotary blade shafts 6, respectively, and each rotary blade shaft 6 is centered on a hollow hollow cylindrical shaft 7 provided near the tip of the boring rod 1. Is rotatably mounted on the outer periphery of an annular body 8 which is rotatably projected, and a bevel gear 9 is attached to the base end of a rotary blade shaft 6 which is projected inside the annular body 8. A bevel gear 10 attached to the cylinder shaft 7 meshes with the bevel gear 10.

As shown in FIG. 5, it is desirable that the stirring blade shaft 6 is provided so as to project as close to the excavation blade 2 as possible so that the soil excavated by the excavation blade 2 is immediately stirred.

When carrying out ground improvement construction using the boring rod 1 constructed as described above, the head of the boring rod 1 is chucked on the rod chuck of the elevator and set on the leader. While being rotated by a motor, it is pressed by an elevating table and lowered along the leader, and the excavation blade 2 at the tip excavates as shown in FIG.

At this time, the bevel gear 10 rotates together with the cylindrical shaft 7 integrated with the boring rod 1 as the boring rod 1 rotates, but the rotary blade shaft 6 projecting from the annular body 8 receives the resistance of the earth and sand to cause the boring rod 1 to rotate. The rotation or rotation of the rotor blade 6 is delayed without following the rotation of the rotor blade, and therefore the rotor blade shaft 6 is rotated about its axis via the bevel gear 9 meshing with the bevel gear 10, and accordingly, the rotor blade shaft 6 is vertically rotated about this shaft. The stirring blade 3 will rotate.

Since there is soil resistance to the rotation of the vertical stirring blade 3, the rotating force of the bevel gear 10 slowly rotates the rotary blade shaft 6 together with the annular body 8 around the rod 1 to vertically rotate the periphery of the rod 1. The stirring blade 3 stirs vertically.

As a result, the soil excavated by the excavation blade 2 is rotated and stirred in the vertical direction by the rotation of the vertical rotating blade 3 in the drilled hole, and the soil is vertically and horizontally stirred together with the horizontal stirring blade 4 which stirs in the horizontal plane. Stir evenly and surely.

Therefore, when the boring rod 1 is rotationally excavated as shown in FIG. 2 or when the boring rod 1 is rotated and pulled up after being excavated to the designed depth as shown in FIG. 3, the cement is put in the boring rod 1. By pumping the ground hardening material such as milk and injecting it into the excavating soil from the discharge port 5, the excavating blade 2, the vertical stirring blade 3 and the horizontal stirring blade 4 make the excavating soil and the ground hardening material uniform in the vertical and horizontal directions. Be sure to stir and mix.

After pulling up the boring rod 1 while stirring the excavated soil and the ground hardening material in this way, as shown in FIG. 4, the excavated soil in the drilled hole is homogeneously solidified with the ground hardening material to form an underground formation. The pile 11 is constructed.

By performing the above-mentioned construction successively at required intervals to construct a large number of underground piles 11 adjacent to each other, the soft ground or the like having insufficient bearing capacity is improved to a stable ground.

As shown in FIG. 5, the boring rod 1 is composed of a double pipe in which the inner and outer pipes 12 and 13 rotate independently, and a bevel gear 10 is attached to the inner pipe 12 near the tip thereof. The bevel gear 9 of the rotary blade shaft 6 protruding from the outer pipe 13 is meshed with the outer pipe 13 to rotate the inner pipe 12 to make the inner pipe 12 stand still, or the inner pipe 12 is reversed with respect to the outer pipe 13. Alternatively, by rotating the rotary blade shaft 6 around the rod 1 by rotating the rotary blade shaft 6 while rotating the rotary blade shaft 6, the rotary blade shaft 6 is rotated around its axis through the bevel gear 9 that meshes with the bevel gear 10. The vertical stirring blade 3 may be rotated around the lever axis.

In this case, the ground hardening material is fed under pressure into the inner pipe 12 to be ejected from the discharge port 5 provided at the tip thereof, or is fed between the outer pipe 13 and the inner pipe 12 so that the outer pipe 13 can be discharged. You may make it eject from the discharge port 5 provided near the tip.

[0023]

As described above, according to the present invention, the excavated soil and the ground hardening material are uniformly and vertically and horizontally provided by the excavating blade that swirls in the horizontal plane, the horizontal stirring blade, and the vertical stirring blade that rotates in the vertical direction. It is possible to stir and mix with each other, which makes it possible to construct a highly reliable and stable underground formation pile in which the excavated soil is uniformly solidified.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a ground improvement device according to the present invention.

FIG. 2 is a vertical cross-sectional side view showing an example of a construction state by the ground improvement device according to the present invention.

FIG. 3 is a vertical cross-sectional side view showing an example of a construction state by the ground improvement device according to the present invention.

FIG. 4 is a vertical cross-sectional side view showing an underground construction pile constructed by the ground improvement device according to the present invention.

FIG. 5 is a vertical cross-sectional side view showing another aspect of the ground improvement device according to the present invention.

[Explanation of symbols]

 1 Boring Rod 2 Excavation Blade 3 Vertical Stirring Blade 4 Horizontal Stirring Blade 5 Discharge Port 6 Rotor Blade Axis 7 Cylindrical Axis 8 Annular Body 9 Bevel Gear 10 Bevel Gear 11 Underground Construction Pile 12 Inner Tube 13 Outer Tube

Claims (5)

[Claims] 1. A rotary blade shaft having a hollow shaft provided with an excavation blade projecting laterally at the tip thereof, and a vertical stirring blade provided on the outer circumference of the tip end portion above the hollow shaft so as to be rotationally driven about its axis. A boring rod for ground improvement, characterized in that a horizontal stirring blade is laterally projected on the outer periphery of the tip end portion, and a discharge port for the ground hardening material is provided near the tip end portion. 2. A rotary blade shaft having a hollow shaft provided with an excavation blade projecting laterally at the tip thereof, and a vertical stirring blade provided on the outer periphery of the tip end portion above the hollow shaft so as to be rotationally driven around the axis thereof. The horizontal stirrer is projected laterally on the outer periphery of the tip, and a discharge port for the ground hardening material is provided near the tip.The vertical stirrer is attached to each of a plurality of horizontal rotary blade shafts. The rotary blade shaft is rotatably projected on the outer periphery of an annular body that is rotatably mounted about this axis on a small diameter cylindrical shaft provided near the tip of the boring rod. A ground improvement boring rod, wherein a bevel gear is attached to a base end of the shaft, and the bevel gear attached to the cylinder shaft 7 is meshed with the bevel gear. 3. A hollow double tube having an inner tube and an outer tube which can rotate independently of each other. An excavating blade is laterally projected at the tip of the outer tube, and a vertical stirring blade is provided around the outer periphery of the tip of the outer tube above the outer tube. A rotary impeller shaft is laterally projected so that it can be driven to rotate around its axis, and a horizontal stirring blade is laterally projected on the outer periphery of the tip of the outer tube, and a ground hardening material discharge port is provided near the tip. A boring gear for ground improvement, wherein a bevel gear is attached near the tip of the inner pipe, and a bevel gear of a rotary blade shaft protruding from the outer pipe is meshed with the bevel gear. 4. An excavating blade is horizontally projected at the tip of a hollow shaft, and a rotary blade shaft provided with a vertical stirring blade around the outer periphery of the upper tip is projected laterally so as to be rotatable about its axis. The horizontal stirrer is projected laterally on the outer periphery of the tip, and the boring rod is provided with a discharge port for the ground hardening material near the tip. While rotating the stirring blade, press fit into the ground and excavate,
By pumping the ground hardening material into the boring rod at the time of the rotary excavation and injecting it into the excavated soil from the discharge port, the excavated soil, the vertical stirring blade, and the horizontal stirring blade form the excavated soil and the ground hardening material vertically and horizontally. Mixing and rotating the boring rod after excavating to the design depth, pulling up while rotating the vertical stirring blade around its axis together with the rotary blade axis, solidify the excavated soil and construct an underground pile. A characteristic ground improvement method. 5. A rotary blade shaft provided with an excavation blade projecting laterally at the tip of a hollow shaft, and a vertical stirring blade provided around the outer periphery of the tip end portion above the hollow shaft so as to be rotationally driven around its axis so as to project laterally. The horizontal stirrer is projected laterally on the outer periphery of the tip, and the boring rod is provided with a discharge port for the ground hardening material near the tip. While rotating the stirring blade, press fit into the ground and excavate,
After excavating to the design depth, the boring rod is rotated, and the vertical stirring blade is rotated around the axis together with the rotary blade axis while being pulled up, and at the same time, the ground hardening material is pressure-fed into the boring rod to excavate in the excavated soil from the outlet. By injecting into the ground, the excavating soil, the vertical agitating blade, and the horizontal agitating blade mix the excavated soil and the ground-hardening material vertically and horizontally, and solidify the excavated soil to construct an underground pile. Ground improvement method.