JP3182586B2 - Construction method of soil cement composite pile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a soil cement composite pile applied to construction-related foundation work.

[0002]

2. Description of the Related Art Hitherto, Japanese Patent Application No. 2-316532 has been applied for a method for forming a soil cement composite pile. 8 to 13 are cross-sectional views showing the construction order of the method for forming a soil cement composite pile. First, as shown in FIG. 8, a hole 10 is drilled while a solidifying material such as cement milk is injected from the vicinity of the tip of the excavating / stirring rod 1. Excavation
The stirring rod 1 performs excavation and stirring. The rod 1a is hollow, and the hollow is a flow path for a solidified material. At the tip, a bit 3 and a stirring blade 4 are provided. In the upper part, a counter-rotation prevention device 5 having a diameter larger than the diameter of the excavation hole is provided.
It is provided rotatably via a boss 6. A discharge hole (not shown) for the solidified material is provided in the vicinity of the tip of the rod 1a, for example, at an appropriate position of the bit 3, so that the solidified material can be ejected by being connected to the flow path in the rod 1a. . Therefore, when a rotation and a pressing force (feeding force) are given to the excavating / stirring rod 1, the excavating / stirring rod 1 is excavated by the bit 3 and is agitated by the stirring blade 4 and the co-rotation prevention device 5, so that the inside of the drilling hole is not ground soil The solidified material is agitated and mixed to form the soil cement 2a, and the holes 10 are drilled.

[0003] Next, when drilling 10 to a predetermined depth, the drilling is stopped, and as shown in FIG. 9, injection of the solidified material is performed by setting the compression strength after solidification to be relatively larger than that of the solidified material injected up to that time. The material is switched to a material and the drilling bottom is filled with the solidified material 2b. However, the drilling may be performed by injecting a solidified material having relatively large strength for a distance necessary for solidifying the drilling bottom. After that, the excavating / stirring rod 1 is pulled up while rotating.

[0004] Then, as shown in FIG.
The drilling holes 10 are filled with the solidified material 2b having a relatively high compressive strength after solidification, and are formed into soil cement 2a in the other areas. Thereafter, as shown in FIG. 11, the hollow tube 11 having a spiral blade 121 on the outer peripheral surface at the lower end thereof is buried in the borehole 10 by applying a downward pressure as necessary while rotating. The spiral wing 121 of the hollow tube 11 has a predetermined width and is attached so as to be substantially one or more rounds. The number of the spiral wings 121 may be one or plural, and one of the spiral wings 121 may have a predetermined length of not more than one turn but not more than one turn.

Further, the piles may be mounted in multiple stages with respect to the entire length. The hollow tube 11 is buried so as to reach a portion of the solidified material 2b having a relatively large compressive strength after solidification at the bottom of the drilled hole 10. When the length is insufficient (in most cases), the hollow tube 12 is connected and buried as shown in FIG. In this connection, the lower hollow tube 11 is supported by a clamp device 13 and the like, and the hollow tube 12 is concentrically connected to the upper portion by screwing or welding. Thus, as shown in FIG. 13, the hollow pipes 11 and 12 are buried in the soil cement columns 2a and 2b in the borehole 10, and the formation of the soil cement composite pile is completed.

[0006]

However, the cement composite pile constructed by the above-mentioned conventional method is implemented by a method called pre-boring. That is, since the hollow pipe (pile) 11 is later set in the soil cement column,
The vertical accuracy of the hollow tube 11 was poor, causing misalignment.

Further, when an earthquake occurs, a bending moment is generated at the head of a pile of a building or a structure by a horizontal force, so that a hollow pipe (pile) 12 shown in FIGS.
S with concrete liner added inside hollow tube
Conventionally, a C pile was used. However, since the inner diameter of this SC pile is smaller than the outer diameter, an auger rod is inserted into the hollow part of the pile to feed the pile and the auger rod simultaneously. The digging method could not be performed because the auger rod could not be inserted.

The present invention has been made in view of the above-mentioned circumstances, and a cement which can arrange an SC pile at the top of a pile by using a middle boring method and a pre-boring method with good vertical accuracy. It is intended to provide a method for forming a composite pile.

[0009]

According to the method for forming a soil cement pile of the present invention, at least one stabilizer is rotatably fitted in the auger rod in the middle of the auger rod, and a drilling wing is provided at the tip of the auger rod. An agitating blade and an anti-corotating blade are disposed on the upper stage, and the excavating blade and the agitating blade are each pivotally connected to a support member fixed to an auger rod by a pivot. The anti-corotating blade is supported via a supporting member. Along with being freely rotatably fitted to the auger rod, and pivotally attached to the support member by a pivot, the excavating wing, the stirring blade and the co-rotation prevention wing are held in an expanded state by the support member with the pivot and the shear pin, respectively. The auger is prepared on the ground, and has at least one spiral blade having a predetermined width, which is separately prepared, at least at an outer periphery of a lower end portion, and the spiral blade is wound over a predetermined length. Inserting the auger rod into the steel pipe pile with the excavating wing, the stirring blade, and the co-rotating wing preceding the lower end of the steel pipe pile from the lower end of the steel pipe pile, and setting the auger rod and the upper end of the steel pipe pile respectively. While holding the work machine, rotating the auger and the steel pipe pile respectively,
At the same time, a process of feeding a predetermined number of steel pipe piles to the ground while feeding the slurry-like solidified material from the auger tip to the predetermined depth of the ground, and then stopping the rotation and feeding of the steel pipe piles, and removing only the auger While rotating, simultaneously eject the slurry-like solidifying material from the auger tip,
A step of feeding the SC pile for a predetermined distance in anticipation of the length of the SC pile to be added to the upper end of the steel pipe pile, and then discharging the solidified material into a slurry-like solidified material having a higher compressive strength than the solidified material discharged until then. And then filling the solidified material at the bottom of the drilled hole with the solidified material, and then fixing the upper end of the steel pipe pile at the ground, pulling up the auger, cutting the shear pin, co-rotating wings, stirring A step of closing and closing the wings and the excavation wings in the steel pipe pile and lifting the auger to the ground, and then adding a SC pile to the steel pipe pile whose upper end is fixed on the ground,
Next, the fixing of the steel pipe pile on the ground is released, and the upper end of the SC pile is gripped by the work machine, and the tip is inserted into the above-mentioned root consolidation section while rotating and feeding.
And inserting the spiral wings .

Further, in the method of forming a soil cement composite pile according to the present invention, at least one stabilizer is rotatably loosely fitted in the auger rod in the middle of the auger rod, and a drilling wing is provided at the tip of the auger rod, and an upper tier is provided thereon. A stirring blade and a counter-rotating blade are provided, and the excavating blade and the stirring blade are each pivotally connected to a support member fixed to an auger rod by a pivot, and the counter-rotating blade is attached to the auger rod via the support member. It is rotatably loosely fitted and pivotally attached to a support member by a pivot, and the excavating wing, the stirring wing, and the co-rotation prevention wing are held in an expanded state by a pivot and a shear pin on the support member, respectively. Prepare on the ground,
A separately prepared, at least one spiral blade having a predetermined width is provided at least on the outer periphery of a lower end portion , and the excavating blade, the stirring blade, and the co-rotating blade are rotated from a lower end of a steel pipe pile around which the spiral blade is wound over a predetermined length. A step of inserting the auger rod into the steel pipe pile with the prevention wing ahead of the lower end of the steel pipe pile, holding the auger rod and the upper end of the steel pipe pile by the working machine, and simultaneously rotating the auger and the steel pipe pile, simultaneously. A step of feeding a predetermined number of steel pipe piles to the ground while adding a predetermined number of steel pipe piles while discharging the slurry-like solidified material from the auger tip, and then stopping the feeding of the steel pipe piles and rotating only the auger. , while ejecting slurry-like solidified material from the auger tip simultaneously auger only pipe pile
Consider the length of the SC pile to be added to the upper end of the
One the step of KyuSusumu only by shallow predetermined distance distance roots consolidated portion of the drilled bottom, then, the discharge of the solidified material, switching of the compressive strength than the solidifying material is large slurry solidified material discharged so far , While discharging the solidified material from the auger tip,
A process of rotating and feeding only the auger by the distance of the root consolidation part at the bottom of the drilling hole, and then fixing the upper end of the steel pipe pile at the ground part, pulling up the auger, cutting the shear pin, co-rotating wings, stirring The process of closing and closing the wing and the excavation wing in the steel pipe pile and lifting the auger to the ground, and then adding the SC pile to the steel pipe pile whose upper end is fixed on the ground,
Unscrew the steel pipe pile from the ground, hold the upper end of the SC pile with a work machine, rotate and feed it, and insert the tip of the spa
And inserting a wail wing .

[0011]

When the auger is pulled out of the pile, the auger can be pulled out because the SC pile is not added to the top.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 7 are half sectional views showing the construction sequence of an embodiment of the present invention. In the figure, reference numeral 20 denotes an auger. The auger 20 is an auger shaft 21, a stabilizer 22 loosely fitted in the middle of the auger, a digging blade 23 mounted on the shaft tip, and a stirring blade 24 fixed to the upper stage.
And an anti-corotating wing 25 rotatably loosely fitted on the upper stage.

A bit 23a is fixed to the excavating wing 23,
The outer diameter of the stirring blade 24 is substantially the same as the outer diameter of the excavating blade 23 and is slightly larger than the outer diameter of the steel pipe pile. The outer diameter of the anti-corotation wing 25 is formed to be larger than the diameter of the excavation wing 23, and during excavation,
As the drilling blades 23 and the stirring blades 24 rotate, the co-rotation preventing blades 25 do not rotate since the holes penetrate into the outer original ground from the drilled wall excavated in the above.

In the figure, the co-rotation preventing blade 2 is provided above the stirring blade 24.
5 are provided, and the stirring blade 24 and the co-rotation prevention blade 25 are provided.
May be interchanged. The co-rotation prevention wing 25 includes:
A large soil mass generated by the excavation wing 23 is crushed, and the large soil mass rotating together with the excavation wing 23 and the stirring wing 24 hits the non-rotating anti-rotation wing. Between the solidified material and the ground to enable uniform kneading of the solidified material and the ground. 23b, 24b,
Reference numerals 25b denote bolts that pivotally support the excavating blade 23, the stirring blade 24, and the co-rotation preventing blade 25, respectively, and are pivotally attached to the support member.

The excavating blade 23, the stirring blade 24 and the co-rotation preventing blade 25 are pivotally supported by the bolts 23b, 24b and 25b so as to be rotatable downward, and are not rotated downward by a shear pin (not shown). Is regulated. 2
Reference numeral 2 denotes a stabilizer, a plurality of sets of which are loosely fitted in the middle of the auger rod 21, and the steel pipe piles to be inserted (reference numerals 31 and 3 in the figure).
It comes into sliding contact with the inside of 2). The stabilizer 22 prevents the deflection of the core of the steel pipe pile during excavation and also prevents the auger rod 21 from bending.

At least one spiral blade 31a having a predetermined width is provided on the outer periphery of the lower end portion of the steel pipe pile 31, and the spiral blade 31a is wound over a predetermined length. A plurality of the spiral blades may be provided on the steel pipe pile 31 or may be provided on a steel pipe pile connected to an upper portion thereof.

Hereinafter, the construction order will be described. First, the auger 20 in the expanded state is set on the steel pipe pile 31 on the ground. Excavating blade 23, stirring blade 24 and co-rotation preventing blade 25
The auger rod 21 is inserted into the steel pipe pile 31 in a state in which is advanced from the lower end of the steel pipe pile 31.

Next, an upper end of each of the auger rod 21 and the steel pipe pile 31 is gripped by a working machine (not shown).
As shown in FIG. 2, the auger 20 and the steel pipe pile 31 are respectively rotated in opposite directions or in the same direction, and simultaneously, a solidified material in the form of slurry is discharged from a discharge port (not shown) at the tip of the auger rod 21 so that the ground is removed. Is drilled with the excavating wing 23. The earth mass excavated by the excavation wings 23 is crushed by the co-rotation prevention wings 25 and mixed with the solidified material discharged from the discharge port while being stirred by the stirring wings 24.

When one steel pipe pile 31 is fed as shown in FIG. 2, one steel pipe pile 32 and one auger rod 21 are then added together as shown in FIG. Next, as shown in FIG. 4, holes are drilled while the solidified material is injected into one piece of the added material, and although not shown, steel pipe piles are successively added and the holes are drilled while the solidified material is injected to a predetermined depth. When the tip of the excavation wing 23 reaches the predetermined depth, the feeding of the steel pipe pile 32 is stopped, and the auger 20 is supplied while rotating the auger 20 and simultaneously discharging the slurry-like solidified material from the auger tip, while supplying the auger for a predetermined distance. Proceed. Next, the discharge of the solidified material is switched to a solidified slurry material having a compressive strength after solidification greater than that of the solidified material injected up to that time, and the bottom of the drill hole is filled with the solidified material to form the root compaction portion 40. In this case, the auger 20 does not feed, but is preferably rotated. This step is called a consolidation step.

Instead of the above-mentioned solidification step, a hole is drilled to a depth of the ground shallower than the predetermined depth shown in FIG. It is also possible to switch to a solidified material having a large compressive strength after solidification, and to drill a hole to a predetermined depth while injecting the solidified material only for the distance of the root fixing portion 40 at the bottom of the hole.

In this case, a solidified material having a compressive strength greater than that of the solidified material that has been drilled to a depth of the ground shallower than the predetermined depth by a distance of the root consolidation portion 40 at the bottom of the drilled hole, and then injected. Then, the auger 20 is rotated and fed while injecting the solidifying material for the distance 40 (hereinafter referred to as the solidifying distance) of the solidified portion at the bottom of the drill hole to reach a predetermined depth, and then the solidified material is injected. Alternatively, the auger rod 21 may be moved up and down by the root compaction distance while rotating the auger rod 21 to perform re-stirring.

Next, as shown in FIG. 5, the upper end of the steel pipe pile 32 is fixed by a clamp device 50 on the ground, and the auger 20 is pulled up to the ground. In this case, the anti-corotating blade 25, the stirring blade 24, and the excavating blade 23 sequentially hit the lower end of the steel pipe pile 31 and shear pins (not shown) are sequentially sheared. It is folded downward around the bolts 23b, 24b, 25b pivotally supporting them and ascends inside the steel pipe piles 31, 32.

Next, as shown in FIG. 6, an SC pile 33 is added above the steel pipe pile 32 whose upper end is fixed on the ground.

Next, as shown in FIG. 7, the fixing of the steel pipe pile 32 on the ground is released, the upper end of the SC pile 33 is gripped by a working machine (not shown), and the tip is sunk in the root fixing portion 40 while rotating and feeding. I do.

[0025]

According to the present invention, as described in detail above, the following effects can be obtained. (1) Except for one SC pile, the steel-pipe pile below the soil-cement composite pile according to the construction method of the present invention is constructed by the middle digging method , and is further inserted in the steel pipe pile.
While discharging slurry-like solidified material from the tip of the
Expect the length of SC pile to add only gar to the top of steel pipe pile
Since the vehicle is fed only a predetermined distance , the vertical accuracy is good and there is no misalignment .

(2) Since the SC pile is used at the top,
Strong against bending moment due to horizontal force at the time of earthquake. ( 3) Spiral wing attached to the tip of steel pipe pile
Pulling the soil cement during construction into the outer periphery of the steel pipe pile
Can be. Therefore, earth removal is discharged to the ground through the pile periphery.
Pile generated by passing through the hollow part of a steel pipe pile
There is no scattering due to earth removal from the head, and the construction site is soiled
There is no. (4) By the spiral wing at the tip of the pile, the tip of the pile is substantially
Steel pipe piles provide greater bearing capacity due to increased area
You.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a construction order according to an embodiment of the present invention.

FIG. 2 is a half sectional view showing a construction order of one embodiment of the present invention.

FIG. 3 is a half sectional view showing a construction order of one embodiment of the present invention.

FIG. 4 is a half sectional view showing a construction order of an embodiment of the present invention.

FIG. 5 is a half sectional view showing a construction order of one embodiment of the present invention.

FIG. 6 is a half sectional view showing a construction order of an embodiment of the present invention.

FIG. 7 is a half sectional view showing a construction order of one embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a construction order of a conventional method for forming a soil cement composite pile.

FIG. 9 is a cross-sectional view showing a construction order of a conventional method for forming a soil cement composite pile.

FIG. 10 is a cross-sectional view showing a construction order of a conventional method for forming a soil cement composite pile.

FIG. 11 is a cross-sectional view showing a construction order of a conventional method for forming a soil cement composite pile.

FIG. 12 is a cross-sectional view showing a construction order of a conventional method for forming a soil cement composite pile.

FIG. 13 is a cross-sectional view showing a construction order of a conventional method for forming a soil cement composite pile.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Auger 21 Auger rod 22 Stabilizer 23 Excavation wing 24 Stirring wing 25 Anti-corotating wing 23b, 24b, 25b Bolt 31, 32 Steel pipe pile 31a Spiral wing 33 SC pile 40 Rooting part 50 Clamping device

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E02D 7/00 E02D 3/12 102 E02D 5/62

Claims (2)

(57) [Claims] 1. A method for forming a soil cement composite pile comprising the following steps. (A) At least one auger in the middle of the auger rod
The stabilizers are rotatably loosely fitted, an excavating wing is provided at the tip of the auger rod, and a stirring wing and an anti-corotating wing are disposed above the auger rod.The excavating wing and the stirring wing are fixed to the auger rod, respectively. The anti-corotating wing is rotatably and loosely fitted to the auger rod via the supporting member, and is pivotally connected to the supporting member by a pivot. The anti-rotation wings are each held by a support member in an expanded state by a pivot and a shear pin. The auger is prepared on the ground, and at least one spiral wing of a predetermined width separately prepared is provided at least on the outer periphery of the lower end. Then, the auger rod is placed in a state in which the excavation wing, the stirring blade, and the co-rotation prevention wing precede the lower end of the steel pipe pile from the lower end of the steel pipe pile around which the spiral wing is wound over a predetermined length. Serial steel pipe is gripped steps of inserting into the pile (B) auger rod and steel pipe pile upper end to a respective work machine, while rotating each auger and steel pipe piles and
Step of feeding a predetermined number of steel pipe piles to the ground while adding a predetermined number of steel pipe piles while simultaneously discharging slurry-like solidified material from the auger tip. (C) Next, stop rotation and feeding of the steel pipe piles, and While simultaneously discharging the solidified material in slurry form from the auger tip, only the auger is placed on the upper end of the steel pipe pile.
Step of feeding a predetermined distance in anticipation of the length of the SC pile to be added (D) Next, the discharge of the solidified material is switched to a slurry-like solidified material having a higher compressive strength than the solidified material discharged so far, Step of filling the solidified material at the bottom of the drilled hole with the solidified material (E) Next, fix the upper end of the steel pipe pile at the ground part, pull up the auger, cut the shear pin, and prevent the co-rotating wing, stirring blade and excavation. Step of closing and closing the wing in the steel pipe pile and lifting the auger to the ground (F) Next, adding the SC pile to the steel pipe pile whose upper end is fixed on the ground. (G) Next, the step of releasing the fixing of the steel pipe pile on the ground, inserting the spiral wing at the tip into the above-mentioned consolidation section while rotating and feeding the upper end of the SC pile with a working machine. 2. A method for forming a soil cement composite pile comprising the following steps. (A) At least one auger in the middle of the auger rod
The stabilizers are rotatably loosely fitted, an excavating wing is provided at the tip of the auger rod, and a stirring wing and a co-rotation preventing wing are disposed at an upper stage thereof, and the excavating wing and the stirring wing are fixed to the auger rod, respectively. The anti-corotating wing is pivotally attached to the auger rod via the supporting member so as to be freely rotatable, and is pivotally mounted to the supporting member by a pivot. Each wing is held in an expanded state by a pivot and a shear pin on a support member, and the auger is prepared on the ground, separately prepared,
At least one spiral blade having a predetermined width is provided at least at the outer periphery of a lower end portion , and the excavating blade, the stirring blade, and the co-rotation preventing blade are wound from the lower end of the steel pipe pile around which the spiral blade is wound over a predetermined length. A step of inserting an auger rod into the steel pipe pile in a state in which the auger rod and the steel pipe pile are moved forward while the work machine grips the auger rod and the upper end of the steel pipe pile, respectively,
Step of feeding a predetermined number of steel pipe piles to the ground while adding a predetermined number of steel pipe piles while simultaneously discharging slurry-like solidified material from the auger tip. (C) Next, stop rotation and feeding of the steel pipe piles, and While simultaneously discharging the solidified material in slurry form from the auger tip, only the auger is placed on the upper end of the steel pipe pile.
A step of feeding a predetermined distance at a predetermined distance in consideration of the length of the SC pile to be added and shallower by a distance equal to the depth of the root fixing portion at the bottom of the drilling hole. (D) Next, the discharge of the solidified material is the solidification that has been discharged so far. (E) Next, a step of switching the solidified material in the form of slurry having a compressive strength greater than that of the material, rotating and feeding only the auger by the distance of the solidified portion at the bottom of the hole while discharging the solidified material from the auger tip. Fixing the upper end of the steel pipe pile on the ground, pulling up the auger, cutting the shear pin, closing the anti-rotating wing, stirring blade and excavating wing in the steel pipe and lifting the auger to the ground (F). Step of adding the SC pile to the steel pipe pile whose upper end is fixed on the ground (G) Next, the fixing of the steel pipe pile on the ground is released, and the upper end of the SC pile is gripped by the working machine while rotating and feeding. Insert the spiral wing at the tip into the consolidation part Process