JP2937745B2 - Ground improvement stirrer and ground improvement method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirrer for forming a solid body having a rectangular cross section in the ground by stirring and mixing excavated soil and a solidified material, and a ground improvement method using the same. .

[0002]

2. Description of the Related Art The ground is excavated with a drill rod to a target depth.
Alternatively, in the method of stirring and mixing the excavated soil and the solidified material discharged from the tip of the excavation rod at the same time as excavation and hardening as it is, a solidified body such as a formation pile is formed in the ground. Since the mixing is performed only with the wings, the completed consolidated body has a columnar shape or a shape that is continuous in the construction progress direction.

[0003] The upper structure supported by the compact is to be constructed on a compact of this shape, whereas the compact has a circular cross-section, whereas the bottom of the structure is usually rectangular. For this reason, in order to completely support the structure, it is necessary to form an unnecessarily large solid body over the bottom surface of the structure, which is inefficient and uneconomical. Based on this point, the applicant has proposed in Japanese Patent Application No. 4-66977 an apparatus for molding a compact into a rectangular cross-sectional shape.

In this method, a box-shaped casing is attached to a rod body,
It is supported in a state insulated from the rotation, and the mixture of excavated soil and solidified material is leveled by a casing into a rectangular shape. However, since the casing moves up and down together with the rod body, the bottom of the consolidated body is formed as shown in FIG. It is left in the shape of a column having a cross-sectional area smaller than the cross-sectional area of the rectangular portion, and there is concern about the bearing strength and shear strength.

[0005] The present invention is an extension of the earlier application, in which a stirrer that reduces the cylindrical portion of the bottom of the consolidated body having a relatively small cross-sectional area and increases the bearing strength and shear strength and the method of construction thereof are added. It is a suggestion.

[0006]

According to the first aspect, the lower end of the casing is positioned near or below the lower stirring blade located at the lowermost position. And the casing is lowered relative to the rod body when the drilling rod is lifted, so that the mixture by the casing is leveled from the bottom of the compacted body, and the compacted body is extended over the entire length. Mold into a rectangular cross section.

The stirring device includes a rod main body connected to the tip of the drilling rod, an upper stirring blade and a lower stirring blade projecting from the peripheral surface of the rod main body at a distance from each other in the axial direction.
A casing having a box-shaped cross section supported by the rod body in a state insulated from its rotation at a distance from the outer peripheral surface of the rod body, and each of an upper stirring blade and a lower stirring blade on the rod body peripheral surface. An upper discharge hole and a lower discharge hole for discharging the solidified material through the inside of the drilling rod are formed at the projecting position. The stirrer stirs and mixes the excavated soil and the solidified material at the time of excavation and withdrawal by the excavation rod, and forms this mixture into a rectangular cross-sectional shape by a casing.

When the casing is located between the upper stirring blade and the lower stirring blade, there is a distance between the lower end of the casing and the lower stirring blade, and the casing does not descend near the lower stirring blade. Is molded into a rectangular cross-sectional shape from a position above the distance from the bottom to the lower end of the casing, and the lower portion is left in a circular cross-sectional shape, but the lower end of the casing is located near the lower stirring blade located at the lowermost position, Alternatively, by lowering the casing or lowering the casing relative to the rod body when the drilling rod is lifted, the distance between the lower end of the casing and the lower stirring blade is eliminated, and the solidified body is cut into a rectangular section from the bottom. It becomes possible to mold into a shape. As a result, the consolidated body becomes a prism over the entire length, and the cross-sectional area of the bottom is increased, so that the supporting strength and the shear strength are improved.

In the latter case, the rod body and the casing are connected to each other so as to be relatively movable in the axial direction, and the casing rises relatively to the rod body when the drilling rod descends, and relatively descends when the drilling rod rises. I do.

In order to increase the cross-sectional area of the cylindrical portion formed only by the stirring blade to about the cross-sectional area of the prismatic portion equalized by the casing, the diameter of the arc drawn by the tip of the stirring blade is set to a diagonal line on the plane of the casing. If the distance is increased, the stirring area extends to the corner of the casing, so that the possibility of the casing rotating with the rotation of the rod body increases, and the smoothing effect of the casing is easily lost, but as described in claim 5, At the outer periphery of each corner of the casing, a resistance plate that extends outside the arc drawn by the tip of the upper stirring blade or lower stirring blade far from the rod body and penetrates into the soil is fixed in a vertical plane. Thereby, the stability of the casing in the soil during rotation of the rod body is enhanced, and the length of the stirring blade can be increased.

The resistance plate protrudes from the outer periphery of the casing from the arc drawn by the tip of the stirring blade to the outer periphery and penetrates into the soil, thereby resisting the rotation of the drilling rod regardless of the expansion of the stirring area by the stirring blade. , To hold the position on the plane of the casing. As a result, the distance between both ends of the stirring blade (diameter of the arc drawn by the tip of the stirring blade) can be extended to the diagonal distance on the plane of the casing, and the tip of the stirring blade draws an arc circumscribing the rectangle of the casing, thereby forming a cylindrical portion. Can be made equal to or larger than the cross-sectional area of the prismatic portion, and an expanded bottom can be formed at the bottom of the consolidated body.

Since the resistance plate is provided at the corner farthest from the center of the rod with respect to the casing, the stability of the casing can be effectively secured even if the length of the resistance plate protruding from the casing is small. In addition, by reducing the length of the protrusion from the casing, the resistance at the time of penetration can be suppressed.

[0013] The expansion of the cross-sectional area of the cylindrical portion may also be achieved by adding at least the lower stirring blade of the rod body to the distal end of the rod body farther from the rod body as described in claim 7 or 8.
This is also possible by rotatably connecting an expanding blade that opens when the rod body rotates forward during excavation rod excavation and increases the distance of the lower stirring blade from the rod body. The expanding wing is closed when the drilling rod is pulled out in the reverse rotation to reduce the distance of the lower stirring blade from the rod body.

According to a seventh aspect of the present invention, the upper stirring blade and the lower stirring blade are provided on the peripheral surface of the rod body so as to be inclined with respect to a horizontal plane, and the expanding blade is rotatable about an axis perpendicular to the surface of the lower stirring blade. Connected to. In claim 8, the expansion blade is rotatably connected around an axis parallel to the plane of the lower stirring blade.

According to the seventh aspect of the present invention, since the stirring blade is inclined with respect to the horizontal, the projected area of the stirring blade on the vertical plane is larger than that in the horizontal case, and the enlarged blade receives from the soil when the rod body rotates. Since the resistance is large, it is easy to open and close the expanding wing.

In the case of the seventh and eighth aspects, as in the case of attaching the resistance plate, the stirring area by the stirring blade is enlarged from the plane area of the casing, so that the expanded bottom is formed at the bottom of the compacted body, and the compacted body is supported. Strength and shear strength are improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, a stirrer 1 according to the present invention has a rod body 2 connected to the tip of a drilling rod (not shown) and Upper stirring blade 3 and lower stirring blade 4 projecting at a distance
And a box-shaped casing 5 supported by the rod body 2 at a distance from the outer peripheral surface of the rod body 2 and insulated from its rotation. And a solidified material are stirred and mixed by an upper stirring blade 3 and a lower stirring blade 4, and the mixture is formed into a rectangular cross-sectional shape by a casing 5. An upper discharge hole 21 and a lower discharge hole 22 for discharging the solidified material through the inside of the excavation rod are formed at projecting positions of the upper stirring blade 3 and the lower stirring blade 4 of the rod body 2.

The rod body 2 has a tubular shape, and the inside thereof serves as an injection pipe for sending the solidified material. The upper discharge hole 21 and the lower discharge hole 22 are located at the upper and lower end positions of the rod body 2 continuously with the injection pipe.
Is dawned.

The upper stirring blade 3 and the lower stirring blade 4 may be provided directly on the outer periphery of the rod body 2, but in the embodiment, the upper housing 6 and the lower housing 7 are put on the outer periphery of the rod body 2, An upper stirring blade 3 and a lower stirring blade 4 are protruded from the housing 6 and the lower housing 7, respectively, and are continuously connected to the upper housing 6 and the lower housing 7 at positions corresponding to the upper discharge holes 21 and the lower discharge holes 22, respectively. Thus, an upper discharge hole 61 and a lower discharge hole 71 are opened.

In the embodiments shown in FIGS. 13 and 18, the discharge of the solidified material from the upper discharge hole 21 and the lower discharge hole 22 is separated, and the extruded material is discharged from the lower discharge hole 22 when excavating, and when discharged.
In order to discharge from the upper and lower housings, the upper housing 6 and the lower housing 7 are circumscribed relative to the rod body 2 so as to be movable up and down relatively by a certain stroke. The distance between the upper discharge hole 61 and the lower discharge hole 71 is made larger than the distance of the upper discharge hole 21. The upper discharge hole 21 is closed by the upper housing 6 which rises due to the resistance of the upward soil when the drilling rod descends. The lower housing 7 which is lowered by resistance closes the lower discharge hole 22.

As described above, the stirrer 1 discharges the solidified material mainly from the lower discharge holes 22 and 71 when the drilling rod descends, and mainly discharges the solidified material from the upper discharge holes 21 and 61 when the drill rod rises.
The solidified material discharged from 2,71 is the lower stirring blade 4 at that position.
Is stirred by the upper stirring blade 3 passing through the position after the discharge. The solidified material discharged from the upper discharge holes 21 and 61 at the time of ascent is agitated by the upper stirring blade 3 at that position and the lower stirring blade 4 passing through the position after discharge. As a result, the solidified material is agitated simultaneously with the advance of the drilling rod, so that the solidified material is efficiently mixed with the excavated soil both when descending and when ascending.

The casing 5 is arranged on the outer periphery of the rod body 2 so as to be insulated from the rotation of the rod body 2 by a bearing 8 rotatably connected thereto.
Is supported by being welded or bolted to the erection member 9 projecting from the outer periphery of the rod body, and penetrates into the soil while the rod acts by the resistance of the surrounding soil acting in the opposite direction when the rod body 2 rotates. The position on the plane is maintained regardless of the rotation of the main body 2.

As shown in FIG. 1, the stirring device 1 of the first embodiment has a lower stirring blade 4 having the lower end 51 of the casing 5 at the lowest position.
By placing it near or below it, the consolidated body 10 is molded into a rectangular cross-sectional shape from the bottom 11 to the top as shown in FIG. FIG. 2 is a plan view of FIG.

In the construction, the excavating rod attached to the stirring device 1 is rotated, the solidified material is discharged from at least the lower discharge hole 22 of the rod body 2, and the excavated soil and the solidified material are stirred by the upper stirring blade 3 and the lower stirring blade 4. After the mixture of the excavated soil and the solidified material stirred by the lower stirring blade 4 is stirred, or excavated while being equalized to the cross-sectional shape of the casing 5 descending with the stirring, at least after the excavation rod reaches a predetermined depth, Discharge hole
The solidified material is discharged from 21 and the mixture of the excavated soil and the solidified material is again stirred by the upper stirring blades 3 and the lower stirring blades 4.
The drilling rod is pulled out while the mixture stirred in the above is stirred or after being formed into a box shape by the casing 5 which rises with the stirring.

In the present invention, since the lower end 51 of the casing 5 is located near or below the lower stirring blade 4, the mixture can be evenly formed in a rectangular cross section from the bottom 11;
The consolidated body 10 is formed in a prismatic shape as shown in FIG. FIG.
In the embodiment, the lower end 51 of the casing 5 is located at an intermediate height between the bit 23 at the tip of the rod body 2 and the lower stirring blade 4. In particular, the height of the casing 5 is increased, and
Is positioned in the vicinity of the bit 23 as shown by the chain line, the consolidated body 10 can be formed into a complete prism up to the bottom 11 as shown by the chain line in FIG.

In the present invention, the height of the casing 5 is increased, which causes a problem of frictional force due to the peripheral soil acting on the outer peripheral surface. The frictional force forms ribs on the outer peripheral surface of the casing 5 in the height direction. Alternatively, it can be reduced by reducing the contact area of the soil by partially drilling holes or the like.

As shown in FIGS. 5 and 6, the stirring device 1 of the third embodiment connects the casing 5 to the rod body 2 so as to be relatively movable in the axial direction. By lowering, the leveling near the bottom 11 of the consolidated body 10 is sufficiently performed.

The casing 5 has a bearing 8 as shown in FIG.
Between the upper housing 6 and the lower housing 7 so as to be movable up and down relative to the rod body 2 by a certain fixed stroke. On the other hand, when the rod body 2 rises, the rod body 2 descends due to the resistance of the downward soil as shown in FIG. When the casing 5 is raised with respect to the rod body 2, the bearing 8 is attached to the upper housing 6.
Stops at the lower end of the lower housing.
Stop at the upper end of the lock.

In the present invention, the lower end 51 of the casing 5 is connected to the lower stirring blade 4 when the rod body 2 is lowered and the casing 5 is raised as shown by a solid line in FIG. By locating near the lower end or below it, the lower end 51 of the casing 5 can be relatively lowered to the level of the bit 23 as shown by the chain line in FIG.
It is possible to form a rectangular cross-sectional shape near the bottom 11 of the consolidated body 10.

If the casing 5 is simply moved up and down with respect to the rod body 2, the absolute level of the casing 5 does not fluctuate from the end of the lowering of the rod body 2 to the start of the ascending. Therefore, as shown in FIG. To the bottom 11,
It is conceivable that the section from the lower end 51 of the casing 5 to the lowermost lower stirring blade 4 is left without being equalized in a rectangular shape. Therefore, in the embodiment shown in FIGS. 7 to 11, the casing 5 is separated from the bearing 8 and the casing 5 is temporarily mechanically moved before the rod body 2 starts to be lifted in order to eliminate the leveling shortage of the bottom 11. When the rod body 2 is raised, the lower stirring blade 4 at the time of the lowering is leveled into a rectangular shape.

On the bearing 8 side of the bridging member 9 fixed to the casing 5, a claw (cam) 91 that engages with the bearing 8 upward when the rod body 2 is lowered and engages downward when the rod body 2 rises around the horizontal axis. It is rotatably supported on The bearing 8 has a length corresponding to the elevation of the casing 5, and an upper flange 81 and a lower flange 82 with which the claws 91 are engaged project from the outer periphery of the upper end and the lower end.

FIG. 7 shows a state in which the rod body 2 is lowered. In this state, the casing 5 rises with respect to the rod body 2 due to the resistance of the soil, and the claws 91 abut against the upper flange 81 of the bearing 8 upward. , Comes into contact with the outer peripheral surface of the bearing 8 and stabilizes, and descends together with the rod body 2.

When the rod body 2 reaches the target depth, the rod body 2 is once pulled up without changing the absolute level of the casing 5 as shown in FIG. As shown in FIG. 11, an axially long groove 83 is formed near the lower flange 82 of the bearing 8 at a position corresponding to the claw 91 on the plane, and when the rod body 2 is pulled up, as shown in FIGS. As shown, the pawl 91 enters the groove 83 from the outer peripheral surface of the bearing 8 and engages upward in the groove 83. In this state, as shown in FIG. 9, the rod main body 2 descends, and the section from the lower end 51 of the casing 5 to the lowermost lower stirring blade 4 at the time of the rod main body 2 being left unmixed due to rotation. Is stirred and mixed.

Then, as shown in FIG. 10, the lower end of the bridge member 9 is
Of the rod body 2 in a state where the casing 5 is lowered relative to the rod body 2.
Is rotated while rising, and stirring is performed again.

FIG. 11 is a plan view of FIG. 7, and FIG. 12 shows the stirring device 1 connected to a biaxial drilling rod.

In the embodiment, the relative vertical movement of the casing 5 and the rod body 2 is mechanically performed by using the pawls (cams) 91. While a spiral track is formed on the inner surface of the bearing 8, a projection that moves along the track is formed on the inner peripheral surface of the bearing 8, and by using the rotation of the rod body 2 with respect to the casing 5, it is also possible to use a hydraulic cylinder. I can do it.

Also in the present invention, by combining with the first aspect, the casing 5
Can be relatively lowered to the level of the bit 23, and it is possible to form a completely rectangular cross-sectional shape from the bottom 11 of the consolidated body 10.

As shown in FIGS. 13 and 14, the stirrer 1 according to claim 5 is provided on the outer periphery of each corner of the casing 5 with the upper stirring blade 3 or the lower stirring blade 4 on the side remote from the rod body 2. The casing 5 is fixed to the casing 5 by projecting outward from the arc drawn by the tip and penetrating into the soil, and fixing the resistance plate 12 which holds the position on the plane of the casing 5 by the resistance of the soil when the excavating rod rotates, in a vertical plane. This enhances the stability in the soil and makes it possible to increase the length of the upper stirring blade 3 or the lower stirring blade 4 to the tip.

The resistance plate 12 is fixed to the casing 5 by a method such as a bolt or a pin which can be easily attached and detached, and is integrated as a part of the casing 5 and is protruded to the outer peripheral side by assembling the casing 5. . In FIG. 14, the resistance plates 12 are fixed in two directions at each corner of the casing 5, but the number and direction of the resistance plates 12 are fixed, such as fixing in a diagonal direction on the plane of the casing 5. It doesn't matter. The resistance plate 12 is removed when sufficient resistance is obtained only by the casing 5.

In the present invention, the stability of the casing 5 is ensured by the resistance plate 12, so that the length of the upper stirring blade 3 or the lower stirring blade 4 is set within the range where the stability is not lost.
14, the distance between the shaft of the rod body 2 and the corner of the casing 5 can be provided. Here, the purpose is particularly to enlarge the cross-sectional area of the bottom 11 of the consolidated body 10, that is, to enlarge the stirring area of the lower stirring blade 4. It is sufficient if the length to be put out is given, and as shown in FIGS. 15 to 17, the stirring area by the lower stirring blade 4 can be larger than the plane area of the casing 5 and the area of the bottom 11 of the consolidated body 10 can be increased. become.

FIG. 16 and FIG. 17 show the completion of the consolidated body 10 when the stirring apparatus 1 of FIG. 13 is continuously stirred or when the stirring apparatus 1 connected to a biaxial drilling rod is used. The state shows that the adjacent consolidated bodies 10, 10 have at least the bottom portions 11, 11
Therefore, it is not necessary to increase the overlapping area in the rectangular portion in order to obtain the unity between the consolidated bodies 10, and the construction can be performed efficiently.

According to the present invention, when the length of the lower stirring blade 4 is within a rectangular shape of the casing 5 on a plane, the lower stirring blade 4 has a prismatic shape over the entire length as shown in FIG. In the case where the lower stirring blade 4 has a length protruding from the casing 5, the lower stirring blade 4 forms the bottom portion 11 which is larger than the rectangular portion as described above. Therefore, the consolidated body 10 having high proof stress can be constructed by itself. The construction is performed in the same manner as in the case of using the stirring device 1 of the first aspect.

As shown in FIG. 18, the stirrer 1 of the seventh aspect opens the lower stirring blade 4 of the rod body 2 at the distal end farther from the rod body 2 when the rod body 2 rotates forward when excavating the rod. To enlarge the distance of the lower stirring blade 4 from the rod body 2 and to close the same when the excavating rod is pulled out in reverse rotation to shorten the distance of the lower stirring blade 4 from the rod body 2.
13 is connected rotatably about an axis perpendicular to the surface of the lower stirring blade 4. FIG. 18 shows the stirrer 1 connected to a biaxial drilling rod. In the case of a single-shaft type, the shape is the same as that of the stirrer 1 in FIG.

FIG. 19 shows a case where the expanding blade 13 is superimposed on the lower stirring blade 4 and is supported by a pin or the like in the out-of-plane direction, so that the expanding blade 13 is opened and closed by the resistance of the soil acting horizontally when rotating. . At the time of forward rotation of the rod body 2 (at the time of descent), as shown in FIG.
At the time of reverse rotation (at the time of ascending), as shown in FIG. 21, it is closed by a resistance indicated by a white arrow. In any case, while the rod body 2 is rotating, the expanding blade 13 is partially engaged with the lower stirring blade 4 to maintain the open state or the closed state.

As shown in FIG. 22, the stirring device 1 of the eighth aspect pivots the expanding blade 13 around an axis parallel to the surface of the lower stirring blade 4 by means of a hinge or the like, thereby removing soil when the rod body 2 is raised and lowered. This is the case where opening and closing are performed by resistance. When the rod body 2 descends (during normal rotation), the enlarged wing 13 opens as shown in FIG. 22 due to the resistance of upward soil indicated by a white arrow. Close with downward resistance as shown.

In claim 7 or claim 8, claim 5
Similarly, when the lower stirring blade 4 has a length that protrudes from the casing 5 in the open state of the expansion blade 13, the lower stirring blade 4 has the bottom portion 11 enlarged from the rectangular portion as shown in FIGS. Form.

In the seventh and eighth aspects, the length of the lower stirring blade 4 is increased when the rod body 2 is lowered, but is shortened when the rod body 2 is raised, so that collision with the casing 5 can be avoided. Combination with 3 is possible,
In order to obtain the stability of the casing 5, it may be combined with claim 5.

The construction is performed in the same manner as in the case where the stirring device 1 of the first or third aspect is used.

[0049]

According to the first aspect of the present invention, the lower end of the casing is positioned near or below the lower stirring blade located at the lowermost position. In the third aspect, the rod body and the casing are relatively movable in the axial direction relative to each other. When the drilling rod is connected, the casing is lowered relative to the rod body when the drilling rod is lifted, so that the mixture by the casing is leveled from the bottom position of the compacted body. The body can be formed into a rectangular cross-sectional shape over the entire length, and the supporting strength and shear strength of the consolidated body can be improved. In particular, by combining claim 1 and claim 3, the consolidated body can be formed into a complete prism up to the bottom.

According to a fifth aspect of the present invention, the outer periphery of each corner of the casing projects outwardly from the arc drawn by the tip of the upper stirring blade or the lower stirring blade on the side farther from the rod body and penetrates into the soil. Since the resistance plate that holds the position on the plane is fixed in a vertical plane, the stability of the casing in the soil during rotation of the rod body can be secured while the rod body is rotating, and the cylinder at the bottom It is possible to make the cross-sectional area of the part equal to the cross-sectional area of the prismatic part, or to form an expanded bottom part that is larger than the cross-sectional area of the prismatic part, further increasing the bearing strength and shear strength of the consolidated body be able to.

According to the fifth aspect of the present invention, the resistance plate is provided at the corner farthest from the center of the rod with respect to the casing, so that the resistance plate can be effectively stabilized even if the length of the resistance plate protruding from the casing is small. In addition, the resistance at the time of penetration can be suppressed by reducing the protruding length from the casing while ensuring the performance.

According to the seventh and eighth aspects, at least the lower stirring blade of the rod main body is opened at the distal end of the rod main body at the time of forward rotation of the rod main body when the excavating rod is excavated, and the distance of the lower stirring blade from the rod main body is increased. Since the expansion blades are connected to enlarge the stirring area by the stirring blades as in the case of attaching the resistance plate to the casing, the stirring area can be enlarged from the plane area of the casing, and the expansion bottom is formed at the bottom of the consolidated body, The support strength and shear strength of the consolidated body are improved.

In the seventh aspect, since the stirring blade is inclined with respect to the horizontal, the projected area of the stirring blade on the vertical plane is larger than that in the horizontal case, and the expanding blade receives from the earth and sand when the rod body rotates. Since the resistance is large, it is easy to open and close the expanding wing.

[Brief description of the drawings]

FIG. 1 is an elevational view showing a stirring device according to claim 1;

FIG. 2 is a plan view of FIG.

FIG. 3 is a schematic diagram showing a completed state of a conventional compact.

FIG. 4 is a schematic diagram showing a completed state of a consolidated body when the stirring device of claim 1 is used.

FIG. 5 is an elevational view showing a stirring device according to a third embodiment.

FIG. 6 is an elevational view showing a state where a casing of the stirring device of FIG. 5 is lowered.

FIG. 7 is an elevational view showing another stirring device according to claim 3;

FIG. 8 is an elevational view showing a state where the rod body of the stirring device of FIG. 7 is once raised.

FIG. 9 is an elevational view showing a state when the rod body of FIG. 7 once rises and then starts re-descent.

FIG. 10 is an elevational view showing a state when the rod body of FIG. 7 is re-raised.

FIG. 11 is a plan view of FIG. 7;

FIG. 12 is an elevational view showing a stirring device connected to a biaxial drilling rod.

FIG. 13 is an elevational view showing a stirring device according to claim 5;

FIG. 14 is a plan view of FIG.

FIG. 15 is a schematic diagram showing a completed state of a consolidated body when the stirring device of FIG. 13 is used.

FIG. 16 is a schematic diagram showing a completed state of a consolidated body when a stirrer connected to a biaxial drilling rod is used.

FIG. 17 is a plan view of FIG. 16;

FIG. 18 is an elevational view showing a stirring device according to claim 7;

FIG. 19 is a perspective view showing a connection example of enlarged blades of the stirring device of FIG. 18.

FIG. 20 is a plan view showing a state where an enlarged wing of the stirring device of FIG. 19 is opened.

FIG. 21 is a plan view showing a state where an enlarged wing of the stirring device of FIG. 19 is closed.

FIG. 22 is an elevational view showing another connection example of the enlarged wing and its open state.

FIG. 23 is an elevational view showing a state where the enlarged wing of FIG. 22 is closed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stirring device, 2 ... Rod body, 21 ... Upper discharge hole, 22 ... Lower discharge hole, 23 ... Bit, 3 ... Upper stirring blade, 4 ... Lower stirring blade, 5 ... Casing, 51 ... lower end, 6 ... upper housing, 61 ... upper discharge hole, 7 ...
Lower housing, 71: Lower discharge hole, 8: Bearing, 81
…… Upper flange, 82 …… Lower flange, 83 …… Groove, 9
…… Erecting member, 91 …… Claw, 10 …… Fixed body, 11 …… Bottom part,
12 ... resistance plate, 13 ... enlarged wings.

Claims (9)

(57) [Claims] 1. A rod body connected to a tip of a drilling rod, an upper stirring blade and a lower stirring blade projecting from a peripheral surface of the rod body at a distance from each other in an axial direction thereof, and an outer peripheral surface of the rod body. And a casing with a box-shaped cross section supported on the rod body in a state insulated from its rotation, and excavated at the protruding positions of the upper stirring blade and the lower stirring blade on the peripheral surface of the rod body. An upper discharge hole and a lower discharge hole for discharging the solidified material through the inside of the rod are drilled, and the excavated soil and the solidified material are stirred and mixed at the time of excavation and withdrawal by the drilling rod, and the mixture is formed into a rectangular cross-sectional shape. Wherein the lower end of the casing is located near or below the lower stirring blade located at the lowermost position. 2. The excavating rod attached with the stirring device according to claim 1 is rotated to discharge the solidified material from at least a lower discharge hole of the rod body, and the excavated soil and the solidified material are stirred by the upper stirring blade and the lower stirring blade. After the mixture of the excavated soil and the solidified material stirred by the lower stirring blade is agitated or excavated while leveling the cross-sectional shape of the casing descending with the agitation, after the excavation rod reaches a predetermined depth, at least the upper discharge hole The mixture of excavated soil and solidified material is again stirred by the upper stirring blade and the lower stirring blade, and the mixture stirred by the upper stirring blade is molded into a box shape after being stirred or by a casing which rises with stirring. A ground improvement method that pulls out a drilling rod while creating a solid body with a rectangular cross section. 3. A rod body connected to a tip of a drilling rod, an upper stirring blade and a lower stirring blade projecting from a peripheral surface of the rod body at a distance from each other in an axial direction thereof, and an outer peripheral surface of the rod body. And a casing with a box-shaped cross section supported on the rod body in a state insulated from its rotation, and excavated at the protruding positions of the upper stirring blade and the lower stirring blade on the peripheral surface of the rod body. An upper discharge hole and a lower discharge hole for discharging the solidified material through the inside of the rod are drilled, and the excavated soil and the solidified material are stirred and mixed at the time of excavation and withdrawal by the drilling rod, and the mixture is formed into a rectangular cross-sectional shape. The rod body and the casing are connected to each other so as to be relatively movable in the axial direction. The casing rises relatively to the rod body when the drilling rod descends, and moves relatively when the drilling rod rises. A stirrer for improving the ground, characterized by falling down to a height. 4. The excavating rod to which the stirring device according to claim 3 is attached is rotated with the casing raised with respect to the rod main body, and the solidified material is discharged from at least a lower discharge hole of the rod main body, and the upper stirring is performed. The excavated soil and solidified material are agitated by the wings and lower stirring blades, and the mixture of the excavated soil and the solidified material stirred by the lower stirring blades is stirred or excavated while being equalized to the cross-sectional shape of the casing that descends with stirring. After the rod has reached the predetermined depth, the solidified material is discharged from at least the upper discharge hole with the casing lowered with respect to the rod body, and the mixture of the excavated soil and the solidified material is again discharged with the upper stirring blade and the lower stirring blade. After stirring, the mixture stirred by the upper stirring blade is stirred, or the excavating rod is pulled out while forming into a box shape with a casing that rises with stirring to form a solid body with a rectangular cross section. Ground improvement method. 5. A rod body connected to a tip of a drilling rod, an upper stirring blade and a lower stirring blade projecting from a peripheral surface of the rod body at a distance from each other in an axial direction thereof, and an outer peripheral surface of the rod body. And a casing with a box-shaped cross section supported on the rod body in a state insulated from its rotation, and excavated at the protruding positions of the upper stirring blade and the lower stirring blade on the peripheral surface of the rod body. An upper discharge hole and a lower discharge hole for discharging the solidified material through the inside of the rod are drilled, and the excavated soil and the solidified material are stirred and mixed at the time of excavation and withdrawal by the drilling rod, and the mixture is formed into a rectangular cross-sectional shape. The outer periphery of each corner of the casing is provided with an upper stirring blade,
Alternatively, the lower agitating blade protrudes outside the arc drawn by the distal end far from the rod body, penetrates into the soil, resists the rotation of the drilling rod, and holds the vertical position of the casing in a vertical position. A stirrer for ground improvement characterized by being fixed in a plane. 6. The excavating rod attached with the stirring device according to claim 5 is rotated to discharge the solidified material from at least a lower discharge hole of the rod body, and the excavated soil and the solidified material are stirred by the upper stirring blade and the lower stirring blade. After the mixture of the excavated soil and the solidified material stirred by the lower stirring blade is agitated or excavated while leveling the cross-sectional shape of the casing descending with the agitation, after the excavation rod reaches a predetermined depth, at least the upper discharge hole The mixture of excavated soil and solidified material is again stirred by the upper stirring blade and the lower stirring blade, and the mixture stirred by the upper stirring blade is molded into a box shape after being stirred or by a casing which rises with stirring. A ground improvement method that pulls out a drilling rod while creating a solid body with a rectangular cross section. 7. A rod main body connected to a tip of a drilling rod, and upper and lower stirring blades projecting from a circumferential surface of the rod body at an axial distance from each other and inclined with respect to a horizontal plane. And a casing having a box-shaped cross section supported by the rod body in a state insulated from its rotation at a distance from the outer peripheral surface of the rod body, and an upper stirring blade and a lower stirring blade on the rod body peripheral surface. An upper discharge hole and a lower discharge hole for discharging the solidified material through the inside of the drilling rod are drilled at each projecting position of the excavated soil, and the excavated soil and the solidified material are stirred and mixed at the time of excavation and withdrawal by the drilling rod. A device for forming into a rectangular cross-sectional shape, at least at the lower end of the lower stirring blade of the rod main body, which is opened at the time of forward rotation of the rod main body during excavation rod excavation, to the lower stirring blade. An enlarged wing that expands the distance and closes during reverse rotation when the drilling rod is pulled out and reduces the distance of the lower stirring blade from the rod body is rotatably connected around an axis orthogonal to the plane of the lower stirring blade. A stirrer for improving the ground. 8. A rod body connected to a tip of a drilling rod, an upper stirring blade and a lower stirring blade projecting from a circumferential surface of the rod body at a distance from each other in an axial direction thereof, and an outer peripheral surface of the rod body. And a casing with a box-shaped cross section supported on the rod body in a state insulated from its rotation, and excavated at the protruding positions of the upper stirring blade and the lower stirring blade on the peripheral surface of the rod body. An upper discharge hole and a lower discharge hole for discharging the solidified material through the inside of the rod are drilled, and the excavated soil and the solidified material are stirred and mixed at the time of excavation and withdrawal by the drilling rod, and the mixture is formed into a rectangular cross-sectional shape. At least the lower stirring blade of the rod body is opened at the tip of the rod body farther from the rod body at the time of forward rotation of the rod body at the time of excavation rod excavation, thereby expanding the distance of the lower stirring blade from the rod body, and excavating. Ground, characterized in that an enlarged wing, which is closed at the time of reverse rotation when the rod is pulled out and reduces the distance of the lower stirring blade from the rod body, is rotatably connected around an axis parallel to the plane of the lower stirring blade. Stirrer for improvement. 9. A drilling rod provided with the stirring device according to claim 7 or 8 is rotated to discharge solidified material from at least a lower discharge hole of the rod body, and excavated soil is formed by the upper stirring blade and the lower stirring blade. After the mixture of the excavated soil and the solidified material stirred by the lower stirring blade is stirred, or the mixture is excavated while being equalized to the cross-sectional shape of the casing descending with the stirring, after the drilling rod reaches a predetermined depth. The casing which discharges the solidified material from at least the upper discharge hole, again stirs the mixture of the excavated soil and the solidified material with the upper stirring blade and the lower stirring blade, and stirs the mixture stirred by the upper stirring blade or rises with stirring. A ground improvement method in which a drilling rod is pulled out while forming into a box shape to create a solidified body with a rectangular cross section.