JP2010270556A - Soil improving machine, and connected soil improving machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soil improving machine capable of loosening an earth clod small without requiring a turning mechanism to be added, and capable of promoting mixing stirring of the earth clod with cement milk. <P>SOLUTION: An auger head 14 for cutting a soil is attached to a lower end of a boring rod 12, and a discharge port 18 of the cement milk is provided in the distal end thereof. The auger head 14 is rotated along an arrow mark R1 while discharging the cement milk from the delivery port 18, and the soil is cut along an arrow mark DN. A lower moving blade 27 for moving the earth clod upwards is provided in an upper side of he auger 14, and a stirring blade 20 for loosening the earth clod is fixed to an upper side of the lower moving blade 27. The stirring blade 20 has a first stirring blade 22 and a second stirring blade 24, and the second stirring blade 24 is attached to an outer circumferential end of the first stirring blade 22 to direct a plane part to a peripheral wall 12F of the auger 14. An upper moving blade 28 for moving the earth clod upwards is provided in an upper side of the stirring blade 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a ground improvement machine that performs ground improvement and a continuous ground improvement machine.

  The soil cement column wall is constructed by the ground improvement machine. The ground is drilled by rotating a boring rod with an auger head at the tip and a flat stirring blade on the peripheral wall with an auger machine. Cement column wall is built.

  At this time, while injecting cement milk from the discharge port at the tip of the auger head, the ground is cut to a predetermined depth with the auger head, and the ground mass that has been cut is loosened with a stirring blade that rotates integrally with the boring rod. The loosened soil mass and cement milk are mixed and stirred with a stirring blade. After reaching the predetermined depth, the boring rod is pulled up while mixing and stirring.

  However, with the flat stirring blades used in conventional ground improvement machines, the loosening of the clot is partially insufficient, and the mixing and stirring of the clot and cement milk is inhomogeneous, resulting in an unsolidified part. As a result, there is a possibility that the quality (strength, water stoppage) of the soil cement column wall will vary, and an excessive amount of cement milk has been injected in order to avoid deterioration of the quality. This has led to an increase in raw material costs for cement milk and construction sludge treatment costs.

Therefore, a technology has been proposed in which a vertical stirring blade is newly added to a conventional flat stirring blade, the soil mass is loosened with both, and mixing stirring of the soil mass and cement milk is promoted (Patent Document 1).
That is, as shown in FIG. 25, the ground improvement boring rod 80 described in Patent Document 1 is provided with a discharge port 82 of a ground hardening material (cement milk) at the tip of a hollow shaft portion, and a lower end portion. Excavation blades (auger heads) 84 project radially from the peripheral wall 80F.

  Above the auger head 84, a rotary blade shaft 86 projects from the peripheral wall 80F in the radial direction. A vertical stirring blade 88 is fixed to the peripheral wall 86F of the rotary blade shaft 86 with the plane portion 88A facing the peripheral wall 80F. The rotary blade shaft 86 is provided on the peripheral wall 80F so as to be rotatable around the central axis, and rotates around the central axis while rotating integrally with the boring rod 80.

  Above the rotary blade shaft 86, a plurality of stirring blades 90 are fixed to the peripheral wall 80 </ b> F of the boring rod 80. The stirring blade 90 rotates integrally with the boring rod 80.

  Thus, the ground 94 is excavated to a predetermined depth by the auger head 84 while discharging the cement milk from the discharge port 82. The excavated soil mass is subjected to a horizontal and vertical shearing action by the vertical stirring blade 88 and the horizontal stirring blade 90 and is loosened to a small size. After reaching a predetermined depth, the soil cement column 96 is constructed by lifting the boring rod 80 while rotating it in the opposite direction.

  However, in Patent Document 1, since it is necessary to provide the rotating blade shaft 86 rotating around the central axis on the boring rod 80, the rotating mechanism 92 for the rotating blade shaft 86 and the rotating power are required, and the ground improvement machine Becomes complicated and impractical.

JP-A-8-13473

  In view of the above-described facts, an object of the present invention is to provide a ground improvement machine that does not require the addition of a rotation mechanism, loosens the earth lump, and promotes mixing and stirring of the earth lump and cement milk.

  A ground improvement machine according to the invention of claim 1 is provided with an auger head that cuts the ground at the lower end, a boring rod that is rotatable about an axis, and a peripheral wall of the boring rod, A flat plate-shaped first agitating blade provided to be inclined with respect to the shaft and rotating integrally with the boring rod; and a flat portion facing the peripheral wall of the boring rod, and being fixed to the first agitating blade, A flat plate-like second stirring blade that rotates integrally with the first stirring blade.

  According to the invention of claim 1, the ground improvement machine cuts the ground by rotating the auger head attached to the lower end. And the 1st stirring blade provided in the surrounding wall of the rotating boring rod and the 2nd stirring blade fixed to the 1st stirring blade have a certain width in the horizontal surface and the vertical surface of the earth block cut in the original position. At the same time, apply shear force and loosen it.

At this time, a 1st stirring blade and a 2nd stirring blade accelerate | stimulate mixing stirring of the earth lump and cement milk loosened small.
That is, by rotating not only the first stirring blade but also the second stirring blade together with the boring rod, it is possible to loosen the cut soil mass without adding a rotating mechanism. In addition, mixing and stirring of the soil mass and cement milk is promoted.

  As a result, a soil cement column wall with stable quality can be constructed. At this time, it is possible to sufficiently mix and agitate the soil mass and the cement milk with a small amount of cement milk injected, and the construction cost can be reduced. Furthermore, by stabilizing the quality and reducing the amount of cement milk injected, the amount of construction sludge is reduced, leading to an environmental impact reduction effect and cost reduction effect.

  According to a second aspect of the present invention, in the ground improvement machine according to the first aspect, the first agitating blade is inclined in a direction of cutting in the cutting direction, and the flat surface is a curved surface projecting upward or downward. It is characterized by being shaped.

According to the second aspect of the present invention, the first agitating blade that is curved upwardly or downwardly and that is inclined in the cutting direction in the cutting direction rotates integrally with the boring rod.
Thereby, the first agitation blade can loosen the clot with less resistance along the curved surface convex upward or downward during cutting.

  According to a third aspect of the invention, in the ground improvement machine according to the first or second aspect, the second stirring blade is fixed to an outer peripheral end of the first stirring blade.

According to invention of Claim 3, a 2nd stirring blade is fixed to the outer peripheral end of a 1st stirring blade, and rotates integrally with a 1st stirring blade.
Thereby, the earth lump around the outer peripheral end of the first stirring blade is loosened by the shearing action of the second stirring blade in addition to the shearing action of the first stirring blade. In addition, the mixing and stirring of the loosely crushed soil mass and cement milk is promoted.

  According to a fourth aspect of the present invention, in the ground improvement machine according to the first or second aspect, the second stirring blade is provided between an outer peripheral end of the first stirring blade and a peripheral wall of the boring rod. It is characterized by.

According to the fourth aspect of the present invention, the second stirring blade provided between the outer peripheral end of the first blade and the peripheral wall of the boring rod rotates integrally with the first stirring blade.
Thereby, the clot between the outer peripheral end of the first stirring blade and the peripheral wall of the boring rod is loosened by the shearing action of the second stirring blade in addition to the shearing action of the first stirring blade. In addition, the mixing and stirring of the loosely crushed soil mass and cement milk is promoted.

  A ground improvement machine according to the invention described in claim 5 is provided with an auger head that cuts the ground at the lower end, a boring rod that is rotatable around an axis, and a peripheral wall of the boring rod, A flat plate-shaped first agitating blade provided to be inclined with respect to the shaft and rotating integrally with the boring rod; and a flat portion facing the peripheral wall of the boring rod, and being fixed to the first agitating blade, A flat plate-like second stirring blade that rotates integrally with the first stirring blade, and a flat portion facing the peripheral wall of the boring rod is fixed to the first stirring blade, and the second stirring blade and the boring rod And a flat plate-like third stirring blade provided between the peripheral walls and rotating integrally with the first stirring blade.

  According to the invention described in claim 5, the ground improvement machine cuts the ground by rotating the auger head attached to the lower end. The cut in-situ soil block includes the first stirring blade provided on the peripheral wall of the rotating boring rod, and the second stirring blade and the third stirring blade fixed to the first stirring blade. A certain width is applied to the horizontal and vertical surfaces of the soil mass at the same time to apply a shearing force to loosen it.

At this time, a 1st stirring blade, a 2nd stirring blade, and a 3rd stirring blade accelerate | stimulate mixing stirring of the earth cake and cement milk loosened small.
That is, it is not necessary to add a rotating mechanism, the cut soil mass can be loosened, and sufficient mixing and stirring of the soil mass and cement milk becomes possible.

A sixth aspect of the present invention is the ground improvement machine according to the fifth aspect, wherein the second stirring blade is fixed to an outer peripheral end of the first stirring blade.
According to invention of Claim 6, a 2nd stirring blade is fixed to the outer peripheral end of a 1st stirring blade, a 3rd stirring blade is provided between the surrounding wall of a 2nd stirring blade and a boring rod, all are boring. Rotates integrally with the rod.

  Thus, in addition to the shearing action of the first stirring blade, the shearing action of the second stirring blade and the third stirring blade allows the periphery of the outer peripheral end of the first stirring blade and the outer peripheral end of the first stirring blade and the boring rod to The clot between the peripheral walls and around the third stirring blade is loosened. In addition, in a wide range, mixing and stirring of the loosely loosened soil mass and cement milk is promoted.

  A seventh aspect of the present invention is the ground improvement machine according to any one of the first to sixth aspects, wherein the second stirring blade is inclined with respect to a plane perpendicular to the radial direction of the boring rod. It is characterized by being.

  According to the seventh aspect of the present invention, the second stirring blade is fixed while being inclined with respect to a surface orthogonal to the radial direction of the boring rod, and in the inclined state, the second stirring blade is integrated with the boring rod. Rotate.

  Thereby, the horizontal force which a 2nd stirring blade exerts on a clot becomes large, and the horizontal movement of a clot and cement milk is promoted. As a result, the soil mass and the cement milk can be made uniform in the horizontal direction, and the planar deviation is reduced. It also leads to stabilization of soil cement quality (strength, waterstop).

  The invention described in claim 8 is the ground improvement machine according to any one of claims 5 to 7, wherein the third stirring blade is inclined with respect to a plane perpendicular to the radial direction of the boring rod. It is characterized by being.

  According to the eighth aspect of the invention, the third stirring blade is fixed to the surface that is inclined with respect to the surface perpendicular to the radial direction of the boring rod, and the third stirring blade is integrated with the first stirring blade in the inclined state. And rotate.

  Thereby, the horizontal force which a 3rd stirring blade exerts on a clot becomes large, and the horizontal movement of a clot and cement milk is promoted. As a result, the soil mass and the cement milk can be made uniform in the horizontal direction, and the planar deviation is reduced.

A ninth aspect of the present invention is the ground improvement machine according to the first to eighth aspects, characterized in that the flat surface portion of the second stirring blade has an outwardly convex curved shape.
According to the ninth aspect of the present invention, the second agitating blade whose planar portion has an outwardly convex curved shape rotates integrally with the first agitating blade. Thereby, the 2nd stirring blade can loosen a clot with little resistance along the curved surface shape convex outside.

  A tenth aspect of the present invention is the ground improvement machine according to the fifth to eighth aspects, characterized in that the flat surface portion of the third stirring blade has an outwardly convex curved shape.

  According to invention of Claim 10, the 3rd stirring blade in which the plane part was made into the curved surface shape convex outside is rotating integrally with the 1st stirring blade. Thereby, the 3rd stirring blade can loosen a clot with little resistance along the curved surface shape convex outside.

An eleventh aspect of the present invention is the ground improvement machine according to any one of the first to eighth aspects, wherein the second agitating blade is a hollow portion in which a central portion of a flat portion of the second agitating blade is removed. It is characterized by being a wing.
According to invention of Claim 11, the 2nd stirring blade from which the center part of the plane part was extracted is fixed to the 1st stirring blade, and is rotating integrally with the 1st stirring blade.

  Thereby, when the earth lump given centrifugal force by the first stirring blade rotating integrally with the boring rod moves through the hollow portion of the second stirring blade, the surrounding area of the hollow portion of the second stirring blade The soil block is rolled up and loosened around the hollow section.

  In addition, since the movement of the soil block around the first stirring blade is promoted by the soil block given centrifugal force by the first stirring blade, the supply of the soil block at the position sandwiched between the first stirring blade and the second stirring blade is provided. Rotation is prevented. At the same time, the movement of the small loosened clot is also promoted, and the mixing and stirring of the clot and cement milk is promoted.

  A twelfth aspect of the present invention is the ground improvement machine according to any one of the fifth to ninth aspects, wherein the third stirring blade has a hollow portion in which a central portion of a flat portion of the third stirring blade is removed. It is characterized by being a wing.

  According to invention of Claim 12, the 3rd stirring blade from which the center part of the plane part was extracted is fixed to the 1st stirring blade, and is rotating integrally with the 1st stirring blade.

  Thereby, when the earth lump given centrifugal force by the first stirring blade rotating integrally with the boring rod moves through the hollow portion of the third stirring blade, the periphery of the hollow portion of the third stirring blade The soil block is rolled up and loosened around the hollow section.

  Further, since the movement of the clot around the first agitating blade is promoted by the clot that has been given centrifugal force by the first agitating blade, the provision of the clot at the position sandwiched between the first agitating blade and the third agitating blade is provided. Rotation is prevented. At the same time, the movement of the small loosened clot is also promoted, and the mixing and stirring of the clot and cement milk is promoted.

  A continuous ground improvement machine according to the invention described in claim 13 is a plurality of the ground improvement machines according to any one of claims 1 to 12, arranged in a row in the lateral direction, the first stirring blade, The second stirring blades are arranged so as to enter each other.

  According to a thirteenth aspect of the present invention, a plurality of ground improvement machines according to any one of the first to twelfth aspects are arranged in a row in the horizontal direction, and are provided in the adjacent ground improvement machines. The stirring blade and the second stirring blade enter the rotation region of the first stirring blade and the second stirring blade provided in the adjacent boring rods in a plan view and rotate.

Thereby, construction of a plurality of soil cement column walls can be performed at the same time. At this time, the first stirring blade and the second stirring blade provided in the adjacent ground improvement machine enter the rotation region of the first stirring blade and the second stirring blade that are adjacent to each other, so that the respective first stirring blade and In the portion where the second agitating blades overlap, both the first agitating blades and the second agitating blades exert a shearing action, so that the soil mass is loosened.
At this time, mixing and stirring of the loosely loosened soil mass and cement milk is further promoted.

  In addition, in the inclined 2nd stirring blade described in any one of Claims 7-12, the horizontal force which a 2nd stirring blade exerts on a soil mass becomes large, and the horizontal motion of a soil mass and cement milk Is promoted. As a result, the soil mass and the cement milk can be made uniform in the horizontal direction, and the planar deviation is reduced.

  A continuous ground improvement machine according to a fourteenth aspect of the present invention is a plurality of the ground improvement machines according to any one of the fifth to twelfth aspects, arranged in a row in the lateral direction, the first stirring blade, The second stirring blade and the third stirring blade are arranged so as to enter each other.

  According to the invention described in claim 14, a plurality of the ground improvement machines according to any one of claims 5 to 12 are arranged in a row in the horizontal direction, and the adjacent ground improvement machines are arranged. The first stirring blade, the second stirring blade, and the third stirring blade of the machine enter the rotation region of the first stirring blade, the second stirring blade, and the third stirring blade that are adjacent to each other in a plan view and rotate. ing.

Thereby, construction of a plurality of soil cement column walls can be performed at the same time. At this time, the first stirring blade, the second stirring blade, and the third stirring blade provided in the adjacent ground improvement machine enter the rotation regions of the first stirring blade, the second stirring blade, and the third stirring blade that are adjacent to each other. Thus, in the portion where the first stirring blade, the second stirring blade and the third stirring blade overlap, both the first stirring blade, the second stirring blade and the third stirring blade exert a shearing action, respectively. The clot is loosened smaller.
At this time, mixing and stirring of the loosely loosened soil mass and cement milk is further promoted.

  In addition, in the inclined 3rd stirring blade described in any one of Claims 7-12, the horizontal force which a 3rd stirring blade exerts on a clot becomes large, and the horizontal movement of a clot and cement milk Is promoted. As a result, the soil mass and the cement milk can be made uniform in the horizontal direction, and the planar deviation is reduced.

  Since the present invention has the above-described configuration, it is possible to provide a ground improvement machine that does not require the addition of a rotating mechanism, loosens the clot, and promotes mixing and stirring of the clot and cement milk.

It is a figure which shows the basic composition of the ground improvement machine which concerns on the 1st Embodiment of this invention. It is a figure which shows the detail of the stirring blade of the ground improvement machine which concerns on the 1st Embodiment of this invention. It is a figure which shows the attachment angle to the boring rod of the stirring blade of the ground improvement machine which concerns on the 1st Embodiment of this invention. It is a figure which shows the construction procedure of the ground improvement machine which concerns on the 1st Embodiment of this invention. It is a figure which shows the other basic composition of the ground improvement machine which concerns on the 1st Embodiment of this invention. It is a figure which shows the basic composition of the ground improvement machine which concerns on the 2nd Embodiment of this invention. It is a figure which shows the other basic composition of the ground improvement machine which concerns on the 2nd Embodiment of this invention. It is a figure which shows the basic composition of the ground improvement machine which concerns on the 3rd Embodiment of this invention. It is a figure which shows the other basic composition of the ground improvement machine which concerns on the 3rd Embodiment of this invention. It is a figure which shows the basic composition of the ground improvement machine which concerns on the 4th Embodiment of this invention. It is a figure which shows the basic composition of the ground improvement machine which concerns on the 5th Embodiment of this invention. It is a figure which shows the effect | action of the ground improvement machine which concerns on the 5th Embodiment of this invention. It is a figure which shows the other basic composition of the ground improvement machine which concerns on the 5th Embodiment of this invention. It is a figure which shows the other basic composition of the ground improvement machine which concerns on the 5th Embodiment of this invention. It is a figure which shows the basic composition of the ground improvement machine which concerns on the 6th Embodiment of this invention. It is a figure which shows the other basic composition of the ground improvement machine which concerns on the 6th Embodiment of this invention. It is a figure which shows the basic composition of the continuous ground improvement machine which concerns on the 7th Embodiment of this invention. It is a figure which shows the construction example of the continuous ground improvement machine which concerns on the 7th Embodiment of this invention. It is a figure which shows the other basic composition of the continuous ground improvement machine which concerns on the 7th Embodiment of this invention. It is a figure explaining the effect experiment of the continuous ground improvement machine which concerns on the 7th Embodiment of this invention. It is a figure explaining the effect experiment of the continuous ground improvement machine which concerns on the 7th Embodiment of this invention. It is a figure explaining the result of the effect experiment of the continuous ground improvement machine which concerns on the 7th Embodiment of this invention. It is a figure explaining the result of the effect experiment of the continuous ground improvement machine which concerns on the 7th Embodiment of this invention. It is a figure which shows the basic composition of the continuous ground improvement machine which concerns on the 8th Embodiment of this invention. It is a figure which shows the basic composition of the ground improvement machine of a prior art example.

(First embodiment)
As shown in FIG. 1, the ground improvement machine 10 according to the first embodiment has a boring rod 12 that is rotatable about a central axis C <b> 1. An auger head 14 for cutting the ground is mounted.

  The boring rod 12 is formed of a hollow steel pipe, and is rotated by applying a rotational force by an auger machine (not shown) attached to the top of the pile driving machine.

  A cement milk discharge port 18 is provided at the tip of the auger head 14. While discharging cement milk from this discharge port 18, the auger head 14 is rotated in the direction of arrow R1, and the ground is cut in the direction of arrow DN.

  Above the auger head 14, a lower moving blade 27 for moving the cut soil mass upward is provided. The lower moving wing 27 is formed in a spiral shape and protrudes from the peripheral wall 12F of the boring rod 12 in the radial direction.

  Further, above the lower moving blade 27, a stirring blade 20 that loosens the earth lump moved upward is protruded from the peripheral wall of the boring rod 12 in the radial direction and fixed. The stirring blade 20 is composed of two stages, an upper stage and a lower stage, and a predetermined interval is provided between the upper stage and the lower stage.

  Above the stirring blade 20, an upper moving blade 28 that moves the cut soil mass upward is provided. The upper moving wing 28 is formed in a spiral shape and protrudes from the peripheral wall 12F of the boring rod 12 in the radial direction.

  As shown in FIG. 2, the stirring blade 20 includes a first stirring blade 22 fixed to the peripheral wall 12 </ b> F of the boring rod 12 and a second stirring blade stirring blade 24 fixed to the outer peripheral end 38 of the first stirring blade 22. Have.

  The second stirring blade 24 is made of steel and has a flat plate shape. The second stirring blade 24 is attached to the outer peripheral end 38 of the first stirring blade 22 with the plane portion facing the peripheral wall 12F of the boring rod 12. At this time, the direction of the second stirring blade stirring blade 24 is parallel to the plane P2 orthogonal to the radial direction of the boring rod 12.

  As shown in FIG. 3 (A), the first stirring blade 22 is also made of steel and has a flat plate shape, and is fixed to the peripheral wall 12F at an angle α1 with respect to the central axis C1 of the boring rod 12.

  Thus, when the first stirring blade 22 is integrated with the boring rod 12 and rotated in the direction of the arrow R1, the second stirring blade 24 is also rotated integrally with the first stirring blade, and the boring rod 12 is moved to the arrow. When proceeding in the DN direction, proceed in the direction of cutting into the ground.

As a result, when the rotating first stirring blade 22 and the second stirring blade 24 collide with the cut soil block, the width of the first stirring blade 22 and the second stirring blade 24 on the horizontal and vertical surfaces of the soil block is increased. At the same time, apply shear force to loosen the clot.
At the same time, due to the stirring action of the rotating first stirring blade 22 and the second stirring blade 24, mixing and stirring of the loosely loosened soil mass and cement milk is promoted.

  In this way, not only the first stirring blade 22 but also the second stirring blade 24 fixed to the first stirring blade 22 is rotated integrally with the boring rod 12 to add a new rotating mechanism. It is possible to loosen the cut soil block. In addition, mixing and stirring of the soil mass and cement milk is promoted.

  As shown in FIG. 4 (A), the soil cement column wall is first constructed by attaching the top of the ground improvement machine 10 to an auger machine of a pile driving machine (not shown) and discharging the cement milk from the discharge port 18 while boring rods. The ground 16 is gradually excavated while rotating 12 in the direction of arrow R1 and lowering in the direction of arrow DN. As a result, the excavation hole 26 is formed in the ground 16, and at the same time, the soil mass and the cement milk are mixed and stirred by the first stirring blade 22 and the second stirring blade 24 inside the excavation hole 26.

  Then, as shown in FIG. 4B, when the depth of the excavation hole 26 reaches a predetermined depth D1, the rotation of the boring rod 12 is stopped and the excavation is ended.

  Next, as shown in FIG. 4C, while discharging the cement milk from the discharge port 18, the boring rod 12 is rotated upward (in the direction of arrow R2) while being pulled up (in the direction of arrow UP). Also at this time, the soil block and the cement milk are mixed and stirred by the first stirring blade 22 and the second stirring blade 24.

  Finally, the H-shaped steel as the core material is inserted into the excavation hole 26 where the boring rod 12 is pulled up. If the above steps are repeated, a soil cement column wall with stable quality can be constructed.

  As a result, it is possible to sufficiently mix and agitate the soil mass and the cement milk with a small amount of cement milk injected, and the construction cost can be reduced. Furthermore, by stabilizing the quality and reducing the amount of cement milk injected, the amount of construction sludge is reduced, leading to an environmental impact reduction effect and cost reduction effect.

  As shown in FIG. 3B, the first stirring blade 22 inclined at an angle α1 with respect to the central axis C1 of the boring rod 12 may have a curved surface (curvature R) convex downward. Thereby, the 1st stirring blade 22 can loosen a clot with little resistance along the curved surface convex downward.

  Further, as shown in FIG. 3C, the first stirring blade 22 inclined at an angle α1 with respect to the central axis C1 of the boring rod 12 may have a curved surface (curvature R) convex upward. Thereby, the 1st stirring blade 22 can loosen a clot with little resistance along the curved surface convex upwards.

  Furthermore, as shown in FIG. 5, the mounting position of the second stirring blade 24 may be an arbitrary position between the outer peripheral end 38 and the peripheral wall 12F of the boring rod 12 instead of the outer peripheral end 38 of the first stirring blade 22. Good. Thereby, the same operation and effect as when the second stirring blade 24 is attached to the outer peripheral end 38 of the first stirring blade 22 can be obtained.

(Second Embodiment)
As shown in FIG. 6, the ground improvement machine 30 of the second embodiment is provided with a flat plate-like first stirring blade 22 on the peripheral wall 12 </ b> F of the boring rod 12. The first stirring blade 22 is provided to be inclined with respect to the central axis C <b> 1 of the boring rod 12 and rotates integrally with the boring rod 12.

A flat plate-like second agitating blade 24 is fixed to the first agitating blade 22 with the flat surface portion facing the peripheral wall 12F of the boring rod 12. A flat plate-like third stirring blade 32 is fixed between the second stirring blade 24 and the peripheral wall 12F of the boring rod 12. The second stirring blade 24 and the third stirring blade 32 are integrated with the first stirring blade 22 and rotate about the central axis C1 in the direction of the arrow R1.
Other configurations are the same as those of the first embodiment, and the description thereof is omitted.

  As a result, the in-situ clot cut by the auger head 14 is applied with shearing force by the rotating first stirring blade 22, second stirring blade 24, and third stirring blade 32 with a width in a horizontal plane and a vertical plane. And unpacked small.

  At the same time, the rotating first stirring blade 22, the second stirring blade 24, and the third stirring blade 32 promote the mixing and stirring of the small loosened earth lump and cement milk.

As shown in FIG. 7, the second stirring blade 24 may be positioned not only between the outer peripheral end 38 of the first stirring blade 22 and the third stirring blade 32 but also fixed to the outer peripheral end 38.
Thereby, the same operation and effect as when the second stirring blade 24 is disposed between the outer peripheral end 38 of the first stirring blade 22 and the third stirring blade 32 can be obtained.

(Third embodiment)
As shown in FIG. 8 (A), in the ground improvement machine 34 according to the third embodiment, a first stirring blade 22 made of a steel material and having a flat plate shape is attached to the peripheral wall 12F of the boring rod 12. A second stirring blade 36 made of a steel material and having a flat plate shape is attached to the outer peripheral end 38 of the first stirring blade 22.

At this time, as shown in FIG. 8B, the second stirring blade 36 is inclined at an angle α2 with respect to the plane P2 orthogonal to the radial direction of the boring rod 12. And the 2nd stirring blade 36 rotates in the direction of arrow R1 integrally with the boring rod 12, with the state inclined at the angle α2.
Other configurations are the same as those of the first embodiment, and the description thereof is omitted.

  Thereby, the horizontal force which the 2nd stirring blade 36 exerts on the soil mass and cement milk becomes large, and the horizontal motion of the soil mass and cement milk is promoted. As a result, the mixing of the soil mass and the cement milk is promoted and uniformed in the horizontal direction, and the planar deviation is reduced. As a result, the quality (strength, water stoppage) of the soil cement column wall is stabilized.

  As shown in FIG. 8C, the second stirring blade 37 is formed in an outwardly convex curved surface shape (curvature R), and is inclined at an angle α2 with respect to the surface P2, and the outer periphery of the first stirring blade 22 It may be provided at the end 38. Thereby, the 2nd stirring blade 37 can loosen a clot with little resistance.

  Further, as shown in FIG. 9, the second stirring blade 36 is inclined at an angle α2 with respect to the surface P2, and the outer peripheral end 38 and the peripheral wall of the boring rod 12 are not the outer peripheral end 38 of the first stirring blade 22. You may provide between 12F. Thereby, the same operation and effect as when the second stirring blade 36 is provided at the outer peripheral end 38 of the first stirring blade 22 can be obtained.

(Fourth embodiment)
As shown in FIG. 10, in the ground improvement machine 40 according to the fourth embodiment, the first stirring blade 22 is attached to the peripheral wall 12 </ b> F of the boring rod 12. A second stirring blade 36 is attached to the outer peripheral end of the first stirring blade 22, and a third stirring blade 42 is attached between the peripheral wall 12 </ b> F and the first stirring blade 22.

At this time, each of the second stirring blade 36 and the third stirring blade 42 is inclined at an angle α2 with respect to a plane P2 orthogonal to the radial direction of the boring rod 12. And the 2nd stirring blade 36 and the 3rd stirring blade 42 rotate in the direction of arrow R1 integrally with the boring rod 12 in the state inclined by the angle α2.
Other configurations are the same as those of the first embodiment, and the description thereof is omitted.

  Thereby, the horizontal force which the 2nd stirring blade 36 and the 3rd stirring blade 42 exert on a lump and cement milk becomes large, and the horizontal movement of a lump and cement milk is promoted. As a result, the soil mass and the cement milk can be made uniform in the horizontal direction, and the planar deviation is reduced.

  As shown in FIG. 10 (C), the second stirring blade 37 and the third stirring blade 42 are formed in an outwardly convex curved surface (curvature R) and inclined at an angle α2 with respect to the surface P2. The first stirring blade 22 may be fixed. Thereby, the 2nd stirring blade 37 and the 3rd stirring blade 42 can loosen a clot with little resistance.

(Fifth embodiment)
As shown in FIG. 11, in the ground improvement machine 44 according to the fifth embodiment, the first stirring blade 22 is attached to the peripheral wall 12 </ b> F of the boring rod 12, and the second stirring is performed on the outer peripheral end 38 of the first stirring blade 22. Wings 46 are attached.

The second stirring blade 46 is a hollow blade in which a central portion of a flat portion made of a steel material is removed and only a peripheral portion is left. The second stirring blade 46 is attached in parallel to a plane P2 orthogonal to the radial direction of the boring rod 12, and rotates around the central axis C1 in the direction of the arrow R1 together with the first stirring blade 22.
Others are the same as those in the first embodiment, and a description thereof will be omitted.

  As a result, as shown in FIG. 12, the earth lump provided with the centrifugal force by the first stirring blade 22 rotating integrally with the boring rod 12 moves in the direction of arrow F, and the second stirring blade 46 is hollowed out. When the part is moved, the earth lump around the hollow part of the second stirring blade 46 is rolled up, and the earth lump is loosened around the hollow part.

  Moreover, since the movement of the clot around the first stirring blade 22 in the direction of arrow F is promoted, the rotation of the clot at the position sandwiched between the first stirring blade 22 and the second stirring blade 46 is prevented.

  At the same time, the movement of the small loosened clot and the cement milk is also promoted, and the mixing and stirring of the clot and the cement milk is promoted.

As shown in FIG. 13, the second stirring blade 46 may be provided between the peripheral wall 12 </ b> F of the boring rod 12 and the outer peripheral end 38 of the first stirring blade 22. Thereby, the same effect | action and effect as the case where the 2nd stirring blade 46 is provided in the outer peripheral end 38 can be acquired.
Further, as shown in FIG. 14, the second stirring blade 46 can be inclined at an angle α2 with respect to a plane P2 orthogonal to the radial direction of the boring rod 12.

  Thereby, the horizontal direction force which the 2nd stirring blade 22 exerts on the soil mass becomes large, and the horizontal motion of the soil mass and cement milk is promoted. As a result, the soil mass and the cement milk can be made uniform in the horizontal direction, and the planar deviation is reduced. It also leads to stabilization of the quality (strength and water-stopping) of the soil cement column walls.

(Sixth embodiment)
As shown in FIG. 15, in the ground improvement machine 50 according to the sixth embodiment, the first stirring blade 22 is attached to the peripheral wall 12 </ b> F of the boring rod 12. The first stirring blade 22 is provided with a second stirring blade 46 and a third stirring blade 52, and rotates integrally with the first stirring blade 22.

Each of the second stirring blade 46 and the third stirring blade 52 is a hollow blade in which a central portion of a flat portion made of a steel material is removed and only a peripheral portion is left. The second stirring blade 46 and the third stirring blade 52 are both attached in parallel to the surface P2 perpendicular to the radial direction of the boring rod 12, and are integrated with the first stirring blade 22 around the central axis C1. , Rotate in the direction of arrow R1.
The rest is the same as in the fifth embodiment, and a description thereof will be omitted.

  In this way, by adding the third stirring blade 52, when the earth lump moves through the hollow portion of the third stirring blade 52 due to centrifugal force, the surrounding mass around the hollow portion of the third stirring blade 52 is involved. It is loosened around the hollow part.

  Further, the earth lump is prevented from being rotated around the position between the first stirring blade 22 and the third stirring blade 52. At the same time, the movement of the small loosened clot and the cement milk is also promoted, and the mixing and stirring of the clot and the cement milk is promoted.

  In addition, as shown in FIG. 16, the 2nd stirring blade 46 and the 3rd stirring blade 52 can also be made to incline by the surface (alpha) 2 orthogonal to the radial direction of the boring rod 12, and angle (alpha) 2.

  Thereby, the horizontal force which the 2nd stirring blade 46 and the 3rd stirring blade 52 exert on a lump and cement milk becomes larger, and the horizontal movement of a lump and cement milk is accelerated | stimulated. As a result, the soil mass and the cement milk can be made uniform in the horizontal direction, and the planar deviation is reduced. It also leads to stabilization of soil cement quality (strength, waterstop).

(Seventh embodiment)
As shown in FIG. 17, the continuous ground improvement machine 60 which concerns on 7th Embodiment arranges the three ground improvement machines 10 in a line in the horizontal direction. Thereby, the construction of three soil cement column walls can be performed simultaneously. The positions of the stirring blades 20 are varied in the height direction so that the stirring blades 20 do not collide with each other during rotation.

  In other words, the stirring blade 20 including the first stirring blade 22 and the second stirring blade 24 provided in the central ground improvement machine 10 is composed of the upper stirring blade 20 and the lower stirring blade provided in the ground improvement machine 10 on both sides. 20 is provided.

  As a result, as shown in FIG. 17B, in plan view, the rotation region S1 of the stirring blade 20 of the center ground improvement machine 10 is partly in the rotation region S1 of the stirring blade 20 of the ground improvement machine 10 on both sides. Even if it enters, any of the stirring blades 20 can rotate without collision.

  In the region S2 where the two rotating regions S1 partially overlap, both the stirring blades 20 exert a shearing action, so that the soil mass is loosened smaller. At the same time, the mixing and stirring of the small loosened clot and the cement milk is further promoted.

  In addition, the rotation direction of the stirring blade 20 of the center ground improvement machine 10 differs from the rotation direction of the stirring blade 20 of the ground improvement machine 10 on both sides. In connection with this, the inclination of the 1st stirring blade 22 of the center ground improvement machine 10 and the inclination of the 1st stirring blade 20 of the ground improvement machine 10 of both sides are different directions.

  As shown in FIG. 18, the construction procedure of the continuous ground improvement machine 60 is basically the same as the construction procedure of the ground improvement machine 10 described above, and the description thereof will be omitted. By constructing according to the construction procedure of the ground improvement machine 10 described above, it is possible to construct three soil cement column walls at the same time on the ground 16 at the depth D1.

  At this time, in the three ground improvement machines 10, the ground improvement machines 10 in the center part and the ground improvement machines 10 at both ends have different mounting positions in the vertical direction so that the respective stirring blades 20 do not overlap. . In addition, a continuous member 62 is provided between the lower moving blade 27 and the lower stirring blade 20 so that the three ground improvement machines 10 are not misaligned, and the three are connected in series.

  In addition, although the continuous ground improvement machine 60 was demonstrated using the three ground improvement machines 10, you may connect and use three ground improvement machines 34 and the ground improvement machines 44, respectively. Further, the number of units to be connected may be five instead of three, for example.

Further, as shown in FIG. 19, the second stirring blades 24 of the three ground improvement machines 10 may be inclined at an angle α2 with a plane P2 orthogonal to the radial direction of the boring rod 12. In this case, the horizontal force that the second stirring blade 24 exerts on the soil mass and the cement milk increases, and the horizontal motion of the soil mass and the cement milk is promoted. As a result, the soil mass and the cement milk can be made uniform in the horizontal direction, and the planar deviation between the three ground improvement machines 10 can be reduced. This tendency becomes more prominent in the range S2 where the two rotation ranges S1 overlap.
Next, the stirring effect will be described.

  The stirring effect was compared using the continuous ground improvement machine 60 to which the three types of stirring blades shown in FIG. 20 were attached. Here, the stirring blade A is a conventional stirring blade, and includes only the first stirring blade 22. The stirring blade B is the stirring blade described in the first embodiment, and the second stirring blade 24 is attached to the outer peripheral end of the first stirring blade 22. The stirring blade C is the stirring blade described in the third embodiment, and the second stirring blade 36 attached to the outer peripheral end of the first stirring blade 22 is inclined. The inclination angle was set to 30 degrees with respect to the plane P2 perpendicular to the radial direction of the boring rod 12 by the stirring blade 36.

  The stirring effect was judged by constructing three types of soil cement column walls using each stirring blade and measuring the strength of the soil cement column walls.

  FIG. 21 shows an example of an experimental soil cement column wall 54 constructed by the continuous ground improvement machine 60. The soil cement column wall 54 was taken out from the ground after solidifying. The soil cement column wall 54 is composed of three soil cement columns including a left column 64, a center column 66, and a right column 68, and is continuous with an overlapping portion S2.

The soil cement column wall 54 is cut at the upper end (first stage) and the lower end (fourth stage) at the position of the cutting line 56, and only the central part (second stage and third stage) is used for measurement. It was adopted as a sample.
For the measurement of strength, first, a needle penetration test was performed on the measurement sample, and the variation in strength at the cut surface in the horizontal direction was measured.

FIG. 22 shows the result of the needle penetration test. For each sample constructed with stirring blade A, stirring blade B, and stirring blade C, the result of the second stage of the sample is shown in the upper stage, and the result of the third stage is shown in the lower stage.
The vertical axis and the horizontal axis in each figure both indicate the distance (mm) from the origin. The points indicated by black circles arranged in a grid in the figure are the measurement positions of the needle penetration test.

  In the needle penetration test, the force required for needle penetration was measured at intervals of 15 mm for the second and third stage samples.

  FIG. 22 shows an isointensity diagram by connecting points having the same intensity based on the measurement results. The intensity level is made to correspond to the density of the dots, the high intensity part is indicated by a dark dot, and the low intensity part is indicated by a thin dot.

  From the results, in the stirring blade A, the dark portions of the dots are concentrated in the central portion, and the thin portions of the dodd appear on both sides. This feature has the same tendency in both the second stage and the third stage, and it can be said that the variation in strength is the largest compared to other stirring blades.

  In the stirring blade B, the level of the dark portion of the dot is generally decreased, and the thin portion of the dod is generally increased, and the tendency is slightly similar to that of the stirring blade A, but the degree of variation is small. It can be said that

  In the stirring blade C, the level of the dark portion of the dots is further lowered and is hardly seen. At the same time, almost no thin portion of the dod is seen, and the intensity distribution is small and uniform from the central part to the peripheral part.

  Next, the variation coefficient Vf was calculated using the measurement data. The variation coefficient Vf is a coefficient for grasping the degree of intensity variation. The smaller the variation coefficient Vf, the smaller the variation. Specifically, the coefficient of variation Vf was obtained by calculating the standard deviation value of the intensity from the measurement data at each measurement position for each specimen and dividing the standard deviation value by the average value.

  FIG. 22 also shows this variation coefficient Vf. As a result, in the stirring blade A, the second stage is Vf = 0.40, the third stage is Vf = 0.36, and in the stirring blade B, the second stage is Vf = 0.36, and the third stage is Vf = 0. In the stirring blade C, Vf = 0.32 in the second stage and Vf = 0.21 in the third stage. From the results, the stirring blade A had the largest value of the variation coefficient Vf, and the stirring blade C had the smallest value of the variation coefficient Vf. This is consistent with the evaluation of the intensity distribution described above.

  From this, it can be said that it is effective to attach not only the second stirring blade 22 but also the second stirring blade 24 to make the intensity distribution uniform. Further, in the case where the second stirring blade 24 is provided, if the second stirring blade 36 is inclined like the stirring blade C with the plane P2 orthogonal to the radial direction of the boring rod, the effect is further increased.

Next, the compression test will be described.
FIG. 23 shows the result of the compression test. In the compression test, the continuously provided test body 54 is divided into a left column body 64, a central column body 66, and a right column body 68, and each of the divided column bodies is processed to obtain a test body having the same cross-sectional area. And the compressive strength of the specimen was measured.

  The horizontal axis of FIG. 23 shows the position of the test body before processing, and the vertical axis shows the compressive strength. The characteristic P is the result of the second stage specimen, and the characteristic Q is the result of the third stage specimen.

  From the results, it can be said that the stirring blade A shown in FIG. 23A has a high compressive strength of the central column 66, a low compressive strength of the left column 64 and the right column 68, and a large horizontal variation. Regarding the vertical variation, the values of the characteristic P and the characteristic Q are greatly different in the left column 64, and the variation was observed.

  It can be said that the stirring blade B shown in FIG. 23 (B) has a high compressive strength at a part of the central column 66, and has a slightly large horizontal variation. As for the vertical variation, all of the central column body 66, the left column body 64, and the right column body 68 have large differences depending on their positions, and variation was observed.

  It can be said that the stirring blade C shown in FIG. 23C has little change depending on the positions of the central column 66, the left column 64, and the right column 68, and has little horizontal variation. Regarding the vertical variation, the characteristic P and the characteristic Q substantially coincide, and it can be said that the vertical variation is small.

  From the result of the compression test, it is effective to attach the second stirring blade 24 not only to the first stirring blade 22 but also to the first stirring blade 22 in order to make the strength uniform. It can be said that the effect is greater when tilted like this.

(Eighth embodiment)
As shown in FIG. 24, the continuous ground improvement machine 70 according to the eighth embodiment has three ground improvement machines 30 arranged in a row in the horizontal direction. Thereby, the construction of three soil cement column walls can be performed simultaneously. The positions of the stirring blades 21 are varied in the height direction so that the stirring blades 21 do not collide with each other during rotation.

  That is, the stirring blade 21 including the first stirring blade 22, the second stirring blade 24, and the third stirring blade 32 provided in the central ground improvement machine 30 is an upper stirring blade provided in the ground improvement machine 30 on both sides. 21 and the lower stirring blade 21.

Thereby, in plan view, even if the rotation region S1 of the stirring blade 21 of the center ground improvement machine 30 and the rotation region S1 of the stirring blade 21 of the ground improvement machine 30 on both sides partially overlap, the stirring blades 21 are It can rotate without colliding.
Other configurations are the same as those of the seventh embodiment, and a description thereof will be omitted.

  Thereby, the construction of three soil cement column walls can be performed simultaneously. At this time, the first stirring blade 22, the second stirring blade 24, and the third stirring blade 32 provided in the adjacent ground improvement machine 30 are adjacent to each other, the first stirring blade 22, the second stirring blade 24, and the third stirring blade. By entering the rotation region of the stirring blade 32, the lump is loosened in the overlapping portions.

At the same time, the mixing and stirring of the small loosened clot and the cement milk is further promoted.
In addition, although demonstrated with the ground improvement machine 30, it is not limited to the ground improvement machine 30, You may use the ground improvement machine 40 and the ground improvement machine 50.

DESCRIPTION OF SYMBOLS 10 Ground improvement machine 12 Boring rod 14 Auger head 16 Ground 18 Cement milk discharge port 20 Stirring blade 22 1st stirring blade 24 2nd stirring blade 32 3rd stirring blade 38 Outer peripheral end 46 2nd stirring blade (centering blade)
52 3rd stirring blade (centering blade)
60 Continuous ground improvement machine

Claims (14)

A boring rod equipped with an auger head that cuts the ground at the lower end and made rotatable around the axis;
A flat first stirring blade provided on the peripheral wall of the boring rod so as to be inclined with respect to the axis of the boring rod and rotating integrally with the boring rod;
A flat plate-like second stirring blade that is fixed to the first stirring blade with the plane portion facing the peripheral wall of the boring rod, and rotates integrally with the first stirring blade;
A ground improvement machine.   2. The ground improvement machine according to claim 1, wherein the first stirring blade is inclined in a cutting direction in the cutting direction, and the flat surface portion has a curved surface shape convex upward or downward.   The ground improvement machine according to claim 1 or 2, wherein the second stirring blade is fixed to an outer peripheral end of the first stirring blade.   The ground improvement machine according to claim 1 or 2, wherein the second stirring blade is provided between an outer peripheral end of the first stirring blade and a peripheral wall of the boring rod. A boring rod equipped with an auger head that cuts the ground at the lower end and made rotatable around the axis;
A flat first stirring blade provided on the peripheral wall of the boring rod so as to be inclined with respect to the axis of the boring rod and rotating integrally with the boring rod;
A flat plate-like second stirring blade that is fixed to the first stirring blade with the plane portion facing the peripheral wall of the boring rod, and rotates integrally with the first stirring blade;
A flat plate that is fixed to the first stirring blade with the plane portion facing the peripheral wall of the boring rod, is provided between the second stirring blade and the peripheral wall of the boring rod, and rotates integrally with the first stirring blade. A third stirring blade in the shape of
A ground improvement machine.   The ground improvement machine according to claim 5, wherein the second stirring blade is fixed to an outer peripheral end of the first stirring blade.   The ground improvement machine according to any one of claims 1 to 6, wherein the second stirring blade is inclined with respect to a plane orthogonal to a radial direction of the boring rod.   The ground improvement machine according to any one of claims 5 to 7, wherein the third stirring blade is inclined with respect to a plane orthogonal to a radial direction of the boring rod.   The ground improvement machine according to claim 1, wherein the flat portion of the second stirring blade has a curved surface protruding outward.   The ground improvement machine according to claim 5, wherein the flat surface portion of the third stirring blade has an outwardly convex curved shape.   The ground improvement machine according to any one of claims 1 to 8, wherein the second stirring blade is a hollow blade in which a central portion of a flat portion of the second stirring blade is removed.   The ground improvement machine according to any one of claims 5 to 9, wherein the third stirring blade is a hollow blade in which a central portion of a flat portion of the third stirring blade is removed.   A plurality of ground improvement machines according to any one of claims 1 to 12, wherein a plurality of ground improvement machines are arranged in a row in a horizontal direction, and the first stirring blade and the second stirring blade are arranged so as to enter each other. Machine.   A plurality of ground improvement machines according to any one of claims 5 to 12 are arranged in a row in a horizontal direction so that the first stirring blade, the second stirring blade, and the third stirring blade enter each other. Arranged continuous ground improvement machine.