JP2001032274A - Method and device for driving concrete pipe and expansion head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a method to easily excavate and penetrate an intermediate difficult excavation layer, and bore a load bearing layer such as a bedrock, which has been difficult to excavate. SOLUTION: In this driving method of a hollow concrete pile 1, the hollow concrete pile 1 is embedded in an excavated hole 3 while a ground 2 below the hollow concrete pile 1 is excavated by a rig A. A load bearing layer or an intermediate difficult excavation layer is excavated while the load bearing layer or the intermediate difficult excavation layer is pulverized by applying the striking force by a hammering mechanism of the rig A, the excavated sediment 17 is discharged with the compressed air 18, and the hollow concrete pile 1 is pressed toward the hole bottom with the earth discharged therefrom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of embedding an existing hollow concrete pile or a method of setting a pile in place using a reinforcing bar, a setting device used in the method, and a two-stage expansion of the setting device. It relates to improvement of the head.

[0002]

2. Description of the Related Art For the construction of a cast-in-place hollow concrete pile or a pile using a reinforced cage in place, a driving method is used instead of a driving method from the viewpoint of preventing pollution such as noise and vibration.
Various low-pollution embedding methods have been developed. However, in the conventional embedding method, it is very difficult to excavate and penetrate a layer that is difficult to excavate, such as a boulder layer or a concrete gala layer, or to drill a support layer such as bedrock.

[0003]

The problem to be solved by the present invention is as follows.
Excavation and penetration of intermediately difficult excavated layers such as boulder layers or concrete gala layers existing in the ground, which had been considered difficult in the construction of cast-in-place hollow concrete piles or cast-in-place piles using reinforced cages, or An object of the present invention is to develop a method for easily piercing a support layer, an apparatus for performing the method, and an enlarged head used in the apparatus.

[0004]

The method for placing a hollow concrete pile (1) according to the first aspect of the present invention is a method for excavating a drilling device (A) from the lower end of a hollow concrete pile (1) for burying underground. part
(a) protruding and the ground below the hollow concrete pile (1)
A method of placing a hollow concrete pile (1) in which a hollow concrete pile (1) is buried in a drill hole (3) while excavating (2),
At least a support layer (4) that is difficult to excavate or an intermediate difficult excavation layer (5)
When excavating, the hammer mechanism (B) installed on the excavator (A)
Excavation is performed by crushing the support layer (4) or the intermediate difficult excavation layer (5) by applying the impact force in the excavation direction, and the excavated earth (17) is injected from the tip of the excavator (A) to the bottom of the hole With the compressed air (18), the soil is removed from the gap (7) between the inner surface of the hollow concrete pile (1) and the outer surface of the drilling rig (A), and the hollow concrete pile (1 ). "

According to this, a striking force in the direction of excavation is applied by the hammer mechanism (B) to apply an intermediate difficult excavation layer (5) such as a boulder layer or a concrete gala layer, or a support layer (4) made of rock or hard earth and sand. ) Is excavated while crushing, so that the intermediate difficult-to-drill layer (5) and the support layer (4) can be drilled in a short time, and conventionally, the hollow concrete pile (1), which was considered impossible, Quick low-pollution casting was enabled. In addition, by applying a striking force in the direction of excavation to the ground, the ground is compacted and the surroundings are compacted, and the ready-made hollow concrete pile (1) and excavation hole (3)
The frictional force with the tire can be increased. This is all true when the impact force in the excavation direction is applied to the ground.

[0006] Claim 2 restricts the method of placing the hollow concrete pile (1) according to claim 1, and claims "support layer".
When excavating (4) or intermediate difficult excavation layer (5),
Increase the inner diameter (D2) of (3) from the inner diameter (d) of the soft layer (6). ''
It is characterized by things. In this way, the hollow concrete pile (1) is not fastened by the support layer (4) or the intermediate difficult excavation layer (5), so that the hollow concrete pile (1) can be inserted into the borehole (3).
Pressing in (1) becomes easier.

A third aspect of the present invention further restricts the method of placing the hollow concrete pile (1) according to the first or second aspect. Injecting a hardening material (8) that improves the adhesion to the concrete pile (1) '', and by doing so, the hardening material (8)
The gap created between the excavation hole (3) and the hollow concrete pile (1) can be filled, so that the load applied to the hollow concrete pile (1) is directly transmitted to the excavation hole (3), (1) The support force can be increased.

Claim 4 is a concrete example of the actual method of the present invention. The hollow concrete pile for burying underground (1)
The excavated part (a) of the excavator (A) is projected from the lower end of the excavator, and the hollow concrete pile (1) is buried in the excavation hole (3) while excavating the ground (2) below the hollow concrete pile (1) A method for placing a hollow concrete pile (1), comprising a soft layer (6) and a support layer
When excavating (4), the hammer mechanism installed on the excavator (A)
The drilling hole (3) is drilled while applying crushing force in the excavation direction by (B), and in the soft layer (6), the diameter (d) is approximately equal to the outer diameter of the hollow concrete pile (1). Excavation is performed, and in the intermediate difficult excavation layer (5) and the support layer (4), excavation is performed with a diameter (D2) larger than the outer diameter of the hollow concrete pile (1), and the excavated earth and sand (17) is excavated. The compressed air (18) injected from the tip of (A) to the bottom of the hole was discharged from the gap (7) between the inner surface of the hollow concrete pile (1) and the outer surface of the drilling rig (A), and was discharged. Push the hollow concrete pile (1) into the bottom of the hole and harden it into an enlarged excavation hole (3a) with a diameter (D2) larger than the outer diameter (d) of at least the hollow concrete pile (1) formed in the support layer (4) Lumber
(8) and the lower end of the hollow concrete pile (1) is buried in the hardening material (8). "

In this way, the hollow concrete pile (1) can be pressed into the intermediate hard excavation layer (5) without receiving much resistance, and the hollow concrete pile (1) can be pressed smoothly. I can do it. Then, the supporting strength of the hollow concrete pile (1) can be increased by embedding the lower end portion of the hollow concrete pile (1) in the hardened material (8) injected into the enlarged drilling hole (3a).

[0010] Claim 5 relates to the method for placing a concrete pile (1) according to any one of Claims 1 to 4,
When pushing the hollow concrete pile (1) into (3), push it while rotating it. " By rotating the hollow concrete pile (1) in this way, the ready-made hollow concrete pile can be more easily
(1) can be pushed into the borehole (3).

[0011] Claim 6 is a case of a cast-in-place pile using a "reinforcing cage (1b)". "A drilling hole (3) is drilled by a drilling device (A) to a predetermined depth. The gap (7) between the inner surface of the drilling hole (3) and the outer surface of the drilling device (A) is injected by the air (18) injected from the tip of the drilling device (A) into the excavated soil (17). Remove the earth, then insert a reinforced cage (1b) into the borehole (3),
A method for placing a concrete pile (1a) in which a hardening material (8) for forming a pile is filled into a drill hole (3) while pulling out a drilling device (A), wherein at least a support layer (4) or When excavating the intermediate difficult excavation layer (5), the striking force in the excavation direction is applied by the hammer mechanism (B) provided in the excavator (A), and the support layer (4) or the intermediate difficult excavation layer (5) is applied. It excavates while crushing. "

[0012] According to this, by the impact force in the excavation direction by the hammer mechanism (B), it is possible to easily pierce the support layer (4) or the intermediate difficult excavation layer (5) which is difficult to excavate even in the case of on-site construction, Efficiency is improved. In particular, an effect of consolidation of the ground due to the impact can be expected, and this method is effective in the case of casting on site. Also, if the ground is solid due to shallow excavation, the casing (K) inserted into the excavation hole (3) is unnecessary to prevent collapse of the inner wall of the excavation hole (3), and it will be directly excavated However, when the ground is weak or the excavation hole (3) is deep, the casing (K) is used.

[0013] Claim 7 is another construction method of a cast-in-place pile using a "reinforcing bar (1b)". Two-stage enlarged excavation for forming an enlarged borehole (3a) having a large inner diameter in a support layer (4). Regarding the construction method, `` The drilling rig (A) excavated the drilling hole (3) for pile formation to a predetermined depth from the soft layer (6) to the support layer (4),
(17) Air injected from the tip of the drilling rig (A) to the bottom of the hole (18)
The soil is removed from the gap between the inner surface of the drilling hole (3) and the outer surface of the drilling device (A), and after excavation is completed, a reinforced cage (1b) is inserted into the drilling hole (3), and the drilling hole (3 A method of placing a concrete pile (1a) in which a hardening material (8) for forming a pile is filled, wherein at least a support layer (4) which is difficult to excavate or an intermediate difficult excavation layer (5) is excavated. The hammer mechanism (B) provided in the excavator (A) applies a striking force in the direction of excavation, and the support layer (4) or the intermediate difficult excavation layer (5)
Excavation while crushing, and excavation in the support layer (4) with a diameter (D2) larger than the hole diameter (d) of the soft layer (6). ''
It is characterized by things.

Also in this case, the impact force in the excavation direction by the hammer mechanism (B) can easily pierce the support layer (4) or the intermediate difficult excavation layer (5) which is difficult to excavate even in the case of on-site construction, so that the efficiency of on-site work can be improved. And the effect of consolidation of the ground due to the impact can be expected. The casing (K) can be used as described above, and may not be necessary in some cases. Further, since the enlarged excavation hole (3a) is formed by the support layer (4), the support strength of the cast-in-place pile (1a) is dramatically improved.

According to an eighth aspect of the present invention, in the method for placing a concrete pile (1) according to any one of the first to seventh aspects, "the excavation is performed by rotating the excavator (A)". I do.

A ninth aspect of the present invention relates to an apparatus for setting a hollow concrete pile (1) used in the above-mentioned construction method, wherein the hollow concrete pile (1) for burying underground can pass through the inside of the hollow concrete pile (1). A drilling device (A) for projecting the excavated part (a) from the lower end of the hollow concrete pile (1) to excavate the ground (2) below the hollow concrete pile (1), and drilling the hollow concrete pile (1)
(3) is composed of a press-fitting part (C) for press-fitting, and a driving part (D) for rotating the drilling rig (A), and the drilling rig (A) protrudes from the lower end of the hollow concrete pile (1). Excavating enlarged blades (10) disposed so as to be able to protrude and immerse in the radial direction from the protruding portion (a),
A hammer mechanism (B) for applying a striking force in the excavation direction to the ground, a compressed air supply unit (E), and a hardening material injection device (F) are provided. "

In this case, the excavating enlarged blade (1) of the excavating device (A)
(0) is a single-stage enlargement in which the outer diameter of the hollow concrete pile (1) is substantially equal to the outer diameter of the hollow concrete pile (1); In some cases, the image is enlarged two steps (or multi-step) so as to enlarge to a size larger than that.

The tenth aspect of the present invention restricts the setting device of the hollow concrete pile (1) according to the ninth aspect. It has a multi-stage enlargement function of enlarging or reducing the outer diameter of the pile (1) to approximately the same diameter ”.

[0019] The present invention relates to the hollow concrete pile.
Regarding the two-stage enlarged head (H2) used in the setting device of (1), it is attached to the tip of the drill rod (11), and a storage recess (12) for the enlarged blade (10) is formed on the side surface. Drill body (2
0), and is slidably inserted into a bearing hole (13) formed in the storage recess (12) so as to protrude and retract into the storage recess (12) via a rotation shaft (14). A two-stage enlarged head (H2) constituted by an arranged expanding blade (10) and a rotating shaft (14);
When the rod moves to one side in the bearing hole (13), the drill rod (11)
During rotation of the expansion blade (10), the side of the expansion blade (10)
(0) to the drill body (20) half-open engagement part (1
5) and when the rotating shaft (14) moves inside the bearing hole (13) to the other,
When the drill rod (11) is rotated, the side of the enlarged blade (10) comes into contact with the fully opened engaging portion (16) for fully opening the enlarged blade (10) with respect to the drill body (20). Provided on the inner surface of the place (12). "

According to this, by selecting the half-open engagement portion (15) or the fully-open engagement portion (16), the diameter (d) of the drill hole (3) is adjusted according to the type of the ground (2) during excavation. ) (D2) can be changed freely.

The twelfth aspect relates to the first embodiment of the two-stage enlarged head (H2) according to the eighth aspect, wherein the half-open engaging portion (15) and the fully-open engaging portion (16) are provided in the storage recess (12). In this case, the diameters (d) and (D2) of the borehole (3) can be changed freely during rotation in the same direction. .

[Claim 13] relates to the second embodiment of the two-stage enlarged head (H2) according to claim 8, wherein the half-open engaging portion (15) and the fully-open engaging portion (16) are formed in the storage recess (12). It is provided on the inner side opposite to the side of `` .In this case, the diameter of the borehole (3) is freely changed to (d) (D2) during rotation in the opposite direction I can do things.

"Claim 14" is changed to "Claim 12 or 13"
The half-open engaging portion (15b) and the fully-open engaging portion (16b) are recessed in a stepped manner on the inner surface side. (15b) and the full-open engagement portion (16b), the enlarged blade (10) fitted into the half-open engagement portion (15b) and the full-open engagement portion (16b) is a half-open engagement portion (15b) or Fully open engagement part (16
It is held firmly in b), and the drill hole (3) is formed.

[Detailed Description of the Invention] The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a schematic cross-sectional view of the present apparatus. In general, a pile driver (Ku), a drilling device (A), a driving unit (D) for operating the drilling device (A), a drilling device (A) and a driving unit (D). ), A compressed air supply unit (E) that blows out compressed air (18) from the tip of the drilling device (A), and a hardened material (8) that blows out from the tip of the drilling device (A). And a hardening material supply device (F).

The pile driver (Ku) includes a crane truck (50) and a guide tower unit (5) attached to the crane truck (50) and installed upright at an excavation site.
1) and the guide tower (51)
(D) along the guide tower (51)
2).

The driving unit (D) includes a driving motor (53) for rotating the drilling rig (A) via the drill rod (11), a chuck unit (54) for chucking the tip of the hollow concrete pile (1), and a chuck. Hydraulic cylinder mechanism (55) for raising and lowering part (54), telescopic rod part (56) that expands and contracts in accordance with hydraulic cylinder mechanism (55)
It is composed of

The excavator (A) is composed of a magnifying head (H) and a hammer mechanism (B) which is disposed immediately above the magnifying head (H) and applies a shock to the magnifying head (H).

The hammer mechanism (B) is a cylindrical wear sleeve.
(60), cylinder (61) arranged in wear sleeve (60)
It consists of a piston (62) that moves up and down along with a mechanism that includes a valve (63) .The piston (62) is moved up and down by compressed air, and the piston (62) is hit against the enlarged head (H). To give the striking force to the enlarged head (H).

The enlarged head (H) according to the present invention includes a one-stage enlarged type (H1) as shown in FIGS. 6 to 9 and a two-stage enlarged type (H2) as shown in FIGS. There is a two-stage expansion head
In (H2), when it is possible to switch between the half-open state and the full-open state during the rotation in the same direction, there is a case where the state is changed to the fully-open state during the forward rotation and to the half-open state during the reverse rotation.

First, the one-stage enlargement type enlargement head (H1) will be described. The cross section is as shown in FIG.
Consists of an upper body (20a), a lower fixed drill (20b) and a bearing plate (20c).
The center axis (21) of (20b) is inserted into the center hole of the main body (20a),
It is detachably fixed by a lock member (19).

A discharge hole (22) for a hardening material (8) and compressed air (18) is formed in the center of the drill body (20). Open to the
The fixed side branch hole (22c) is used. The discharge hole (2
The branch branch hole (22a) drilled obliquely downward from 2) branches off and blows out compressed air toward the expanding blade (10). Further, a sub-branch branch hole (22b) is formed obliquely upward from the branch branch hole (22a), and compressed air (18) is blown out so as to push up the excavated earth and sand (17) as described later. ing.

As shown in FIGS. 7 and 8, the fixed drill portion (20b) is formed with a notch (23) so as to avoid the outlets of the holes (22a) (22c). Is a blade (24)
Are formed, and a large number of button bits (25) are implanted concentrated on the entire lower surface of the fixed drill portion (20b), particularly on the blade (24). The button bit (25) is made of a very hard material,
For example, it is made of industrial diamond, cemented carbide, or the like, and its spherical tip projects from the lower surface of the fixed drill portion (20b).

The upper portion of the main body portion (20a) is a mounting shaft portion (26) which is inserted and fixed to the lower end of the hammer mechanism (B). As can be seen from FIG. ) Are protruded, and a fixing member is attached to the lower mounting hole (64) of the wear sleeve (60).
(65).

On the side surface of the drill body (20), a recess (12) for storing the enlarged blade (10) is formed. As can be seen from FIG. 9, the shape of the storage recess (12) is such that when the enlarged blade (10) is folded and stored, the outer shape of the recess is substantially fit in the side surface of the drill body (20). It is formed according to the shape of (10). As shown in FIG. 3, the storage recess (12) is formed by mounting the fixed drill (20b) to the main body (20a) via the bearing plate (20c).

That is, the storage recess (12) is formed on the lower surface of the main body (20a) with the lower surface side open, and the storage recess (12) is formed by attaching the bearing plate (20c) to the lower surface of the main body (20a). ) Is closed at the lower surface opening and is opened only on the side surface side, and becomes a storage recess (12) that can store the enlarged blade (10). In addition, the storage recess (12)
At one end, a bearing hole (13) is bored at a position opposing the bearing plate (20c) and the main body (20a), and a rotating shaft (14) of the enlarged blade (10) is rotatably fitted therein. In.

A rotating shaft (14) fitted into the bearing hole (13) is formed at one end of the enlarged blade (10), and a blade (24) is formed at the other end.
Are formed. And on the lower surface, there is a fixed drill part
A button bit (25) is planted as in (20b). In this case, it is particularly concentrated on the blade part (24).

The hollow concrete pile used in the present invention
For (1), a so-called “pretension type centrifugal high strength prestressed concrete pile” which is already used is used. In this steel, a steel material to which tension has been applied is arranged inside and a compressive stress is applied to concrete to impart strength.

The compressed air supply unit (E) includes one or more compressors (30), a receiver tank (31), a line oiler
(32) and a high-pressure air hose (33), and the high-pressure air hose (33) is connected to the drill rod (11) via the drive unit (D).
The through hole (11a) is connected to the hardening material (8) or compressed air drilled at the center of the drill body (20).
It is connected to the discharge hole (22) for (18).

The hardening material supply device (F) comprises a mixing mixer (41) and a hardening material supply device (40). The hardening material supply device (F) is connected to the high-pressure air hose (33), and is connected to the high-pressure air (18). When the hardening (8) is required when no is supplied, it is activated.

The hardening material (8) is usually in the form of milk made by kneading cement and water, and is used by injecting it into the borehole (3) or when drilling the borehole (3). It also includes soil cement mixed with water and cement mixed with water and cement in the bottom or cavity. In addition, hardening material (8)
It goes without saying that anything other than cement can be used, and the best one is used according to the condition of the ground (2).

Next, the operation of the present invention will be described. First, the crane truck (50) is moved to the excavation site, and is erected on the guide tower (51) in accordance with the excavation site. A drive section (D) is attached to the movable base (52) of the guide tower section (51), and rises to the uppermost position and stops. In this state, a one-stage enlargement type drilling device (A) is attached to the lower end of the driving unit (D) via a drill rod (11). The upper end of the hollow concrete pile (1) is chucked to the chuck portion (54).

Since the concrete pile (1) is a hollow pile,
The drill rod (11) and the drive unit (D) are inserted into the inside, the lower end of the drilling rig (A) is looking through the lower end of the hollow concrete pile (1), and the expanded blade (10) is
(1) It can be enlarged and reduced without hanging on the lower end.
The outer periphery of the hollow concrete pile (1) is covered with a bellows-like elastic cover (34), and the upper end thereof is a chuck (54).
The lower end is installed so as to cover the periphery of the excavation site.

In this state, the drive motor (53) of the drive section (D)
Is rotated and compressed air is supplied to operate the hammer mechanism (B). Drilling rig (A) by rotation of drive motor (53)
Rotates, which causes the enlarged blades (10) to come out of the storage recesses (12).
Open to almost the same diameter as (d) and start excavation. Where the borehole
If the inner diameter (D1) of (3) is slightly larger than the outer diameter of the hollow concrete pile (1), fill the gap between them with cement milk, and if there is no gap, press-fit the hollow concrete pile (1). Go. At this time, if the hollow concrete pile (1) is rotated, press-fitting becomes easier.

The piston of the hammer mechanism (B) operating simultaneously
(62) gives a downward impact to the excavator (A), and continuously breaks the ground (2) with the button bit (25). The ground (2) is composed of a soft layer (6), a boulder layer in the middle of excavation, and an intermediate difficult-to-excavate layer (5) such as a concrete galley layer, and a support layer (4) made of rock or hard earth and sand at the deepest part. ) Is lying. The soft layer (6) is softer and easier to excavate than the intermediate difficult excavation layer (5) and the support layer (4), but the intermediate difficult excavation layer (5) and the support layer (4) are difficult to excavate. Since the soft layer (6) cannot support the weight of the building built on it by the ready-made hollow concrete pile (1), excavation will be performed to the upper layer of the support layer (4) .

During this time, the piston of the hammer mechanism (B)
The compressed air (18) that has actuated (62) escapes from the cylinder (61) simultaneously with the impact of the piston (62), and passes through the through hole (11a) of the drill rod (11) to the discharge hole (22) ) Through the branch holes (22a), (22b) and (22c).

The compressed air (18) is blown out from the branch hole (22c) of the fixed drill portion (20b) toward the hole bottom to push the crushed earth and sand (17) upward. On the other hand, the branch hole (22a) that opens downward from the main body (20a) injects compressed air (18) toward the expanding blade (10), and Prevent the adhesion of sediment (17) that is about to adhere,
Sediment between the bearing hole (13) and the rotating shaft (14) or in the storage recess (12)
(17) is prevented from entering.

Further, the branch hole (22b) opening upward from the main body portion (20a) is used to dig the earth and sand (17) pushed upward by the compressed air (18) from the branch hole (22c). (A) and the drill rod (11) and the gap (7) between the hollow concrete stake (1) to further push upward.
The soil (17) pushed up to the top of the hollow concrete pile (1) through the gap (7) overflows from the hollow concrete pile (1) through a space (not shown) of the chuck portion (54), It falls through between the cover (34) and the hollow concrete pile (1) and accumulates around the hollow concrete pile (1).

The excavation is performed in this manner, and simultaneously with the progress of the excavation, the press-fitting of the hollow concrete pile (1) into the excavation hole (3) simultaneously proceeds. That is, when the bottom of the excavation hole (3) is excavated, the hydraulic cylinder mechanism (55) operates to extend the cylinder rod. As a result, the chuck portion (54) is pushed down, and the hollow concrete pile (1) fixed to the chuck portion (54) is pressed into the excavation hole (3).

As described above, the hollow concrete pile (1) may be pushed only by the pushing operation by the hydraulic cylinder mechanism (55), but the hollow concrete pile (1) as shown in FIG. The rotation mechanism (R) can also be used to smoothly push it in. This mechanism
(R) will be briefly described.

The pile rotation mechanism (R) includes a pile rotation motor (57) attached to the telescopic side portion (56a) of the telescopic rod portion (56), and a drive gear provided on the drive shaft of the pile rotation motor (57). (58), and the drive gear (58) provided on the outer periphery of the chuck portion (54).
And a driven gear (59) meshed with. And
The chuck part (54) is configured to rotate while the hollow concrete pile (1) is chucked.

As described above, the press-fitting of the hollow concrete pile (1) into the excavation hole (3) proceeds simultaneously with the progress of excavation. However, when the pile rotating motor (57) is rotated during the press-fitting, the drive gear (58) is driven. ) Is rotated, and the chuck portion (54) rotates with the hollow concrete pile (1) chucked. When the hydraulic cylinder mechanism (55) is operated at that time, the cylinder rod extends and pushes down the chuck portion (54), and the hollow concrete pile (1) fixed to the chuck portion (54) is inserted into the borehole (3). Press in while rotating. As a result, the hollow concrete pile (1) can be more smoothly pressed into the excavation hole (3).

The function of the compressed air (18) is mainly to drive the piston (62) and to remove the earth and sand (17). In addition, the compressed air (18) is always supplied to the borehole (3). Drilling holes (3)
In some cases, the inside is maintained at a high pressure to prevent springs and collapse of the inner wall of the borehole (3). Further, if necessary, the hardening material (8) is appropriately injected, and the degree of adhesion between the outer surface of the hollow concrete pile (1) and the excavation hole (3) may be improved.

In this way, the ground (2) is excavated toward the hard earth and sand support layer (4). Even if there is an intermediate difficult excavation layer (5) such as a boulder layer in the middle of the excavation. It can be crushed by the action of the hammer mechanism (B) and can be dug to the upper layer of the support layer (4). In this case, the borehole (3)
Is slightly larger than the outer diameter (d) of the hollow concrete pile (1). If the length of the hollow concrete pile (1) or the length of the drill rod (11) is not enough to reach the support layer (4), a new hollow concrete pile (1) or drill rod (11) is required. Will be added on top of it.

As shown in FIG. 17 (b), when the excavation is dug up to the upper layer of the support layer (4), the embedding is completed, and the drive motor (53) is reversed. As a result, as shown in FIG. 17 (c), the enlarged blade (10) is closed and closed in the storage recess (12).

At the same time, the hardening material injection device (F) is operated, and the hardening material injection hole (22c) formed on the side surface of the one-stage enlarged head (H1) is cut into the excavation hole (3) formed in the support layer (4). ) To hardening material (8)
Inject. In the injection of this hardening material (8), drill holes (3)
From head to ready-made hollow concrete pile (1)
(H1) is moved up and down, and the hardening material (8) and the surrounding earth and sand are stirred while the hardening material (8) is filled in the excavation hole (3), and filling and densification of the stirring member into the excavated portion is performed. Plan.

Finally, the hollow concrete pile (1) is press-fitted to a predetermined depth, the expanded blade (10) is closed, and the one-stage enlarged head (H1) is pulled out from the hollow concrete pile (1).
Thereby, the embedding tip of the hollow concrete pile (1) is embedded and fixed in the block formed by hardening the hardening material (8) formed in the excavation hole (3). Thereby, the tip portion of the hollow concrete pile (1) is wrapped in the block, and the hollow concrete pile (1) can be firmly supported by the support layer (4).

Next, the two-stage enlarged head (H2) will be described. In this case, one-stage enlarged head (H1)
The description common to the above is deleted, and different points are mainly described.

First, an enlarged head (H2) of a two-stage enlargement type is shown in FIG.
As shown in FIGS. 10 to 16, when two-stage switching can be performed in the forward rotation (first embodiment = FIG. 11 or 12),
There are two cases: two-stage switching can be performed by changing the rotation direction in the forward and reverse directions (second embodiment = FIG. 15 or 16).

In any case, as shown in FIGS. 11 to 13, the width of the storage recess (12) is formed larger than the width of the enlarged blade (10), and the rotation shaft ( 14) is slidably inserted, and is constantly urged by a spring (37) disposed in the bearing hole (13) of the bearing plate (20c) in a direction in which the expanding blade (10) is pushed up. .

First, the first embodiment will be described. In this case, the half-open engagement that the side surface of the enlarged blade (10) comes into contact with the inner side surface of the storage recess (12) on the bearing hole (13) side during normal rotation to make the half-opening with the drill body (20) A part (15) and a fully open engaging part (16) that makes the enlarged blade (10) fully open with respect to the drill body (20) when the side surfaces of the enlarged blade (10) are in contact with each other are provided in two vertical stages. By sliding the rotating shaft (14) in the bearing hole (13), the half-open engagement part (15) or the full-open engagement part (15) is selected according to the type of the ground (2) during excavation. By selecting (16), the amount of expansion of the expansion blade (10) can be changed freely,
The diameters (D1) and (D2) of (3) can be changed freely.

A brief description will be given of a method of switching the full-width / half-opening of the enlarged blade (10) or storing the expanded blade (10). Expanding feather (1
When the excavator (A) is rotated with the (0) stored in the storage recess (12), the enlarged blade (10) comes out of the storage recess (12) and engages with the half-open engagement portion (15). Half open. As described above, in this state, the rotation trajectory of the tip of the enlarged blade (10) becomes almost the same diameter as the outer diameter (d) of the hollow concrete pile (1),
If there is a gap between (3) and the hollow concrete pile (1), the cement milk is filled, and if there is no gap, press-fitting is performed. At this time, it is effective to rotate the hollow concrete pile (1).

In order to change the state from this state to the fully opened state, in the first embodiment, when the hollow concrete pile (1) is pushed down with respect to the half-opened expanded blade (10), the expanded blade (10) is placed at the lower end of the hollow concrete pile (1). ) Is engaged, the expanding blade (10) is pushed down while pushing and bending the spring (37), and the expanding blade (10) is fully engaged.
(16). When the blade is rotated forward in this state, the enlarged blade (10) is engaged with the fully-open engaging portion (16) to be in a fully-open state.

In the case of the first embodiment, the fully open engagement portion (1
There is a step (15a) provided on the inner surface of the storage recess (12) between the (6) and the half-open engagement portion (15). It does not move to the half-open engagement portion (15) side.
When storing the expansion blade (10), the expansion blade (10) is closed by reversing the two-stage expansion head (H2) and enters the storage recess (12).

On the other hand, in the second embodiment, as shown in FIG. 14, the inside surface of the storage recess (12) on the bearing hole (13) side is contacted with the side surface of the enlarged blade (10) at the time of reverse rotation. The half-open engagement portion (15), which makes contact with the drill body (20) to be half-open, and the side surface of the enlarged blade (10) abuts during normal rotation, and the enlarged blade (10) is brought into contact with the drill body (20).
A fully open engagement portion (16) is provided in two stages up and down, so that the rotation shaft (14) slides and changes the rotation direction in the bearing hole (13) as described above. By doing so, it is possible to freely change the expansion amount of the enlarged blade (10) by selecting the half open engagement part (15) or the full open engagement part (16) according to the type of the ground (2) during excavation. The diameter of the borehole (3) (D1) (D2)
Can be changed freely.

That is, the fully-open engagement portion (16) and the half-open engagement portion (15) are on opposite sides, and the storage portion of the closed enlarged blade (10) is located in the lower half of the storage recess (12). I do. In this case, as described above, when the excavator (A) is rotated, the enlarged blade (10) protrudes from the storage recess (12), and the spring (10) separates from the ceiling (12a) of the storage portion where the expanded blade (10) is detached. It is lifted by the force of 13) and the reaction force when pressed against the ground, and moves to a position where it can be engaged with the fully open engagement portion (16) or the half open engagement portion (15).

When the excavator (A) is reversed in this state,
The enlarged blade (10) engages with the half-open engagement portion (15), and excavates in the half-open state described above. If you want to excavate with the expansion blade (10) fully open, you only need to rotate the drilling rig (A) forward.When the drilling rig (A) rotates forward, the expansion blade (10) turns over and is fully opened. Engage with the engaging portion (16).

It should be noted that, as shown in FIGS.
And the half-open engagement portion (15) with the full-open engagement surface (16a) and the half-open engagement surface.
(15a) can also be formed in a stepped shape, and in this way, the enlarged blade (10) is firmly held by the fully open engagement portion (16) and the half-open engagement portion (15) and is swung. Excavation becomes easier.

Next, an excavation example using the two-stage enlarged head (H2) will be described. The excavation method is almost the same as in the case of the one-stage enlarged head (H1). However, when approaching an intermediate difficult excavation layer (5) such as a boulder layer and a concrete gala layer in the middle of excavation,
Fully open the expanded blades (10) and excavate a large area with respect to the outer diameter of the hollow concrete pile (1). By doing so, tightening of the hollow concrete pile (1) by the intermediate difficult excavation layer (5) is avoided, and press-fitting is facilitated. However, intermediate difficult excavation layer (5)
Since a gap is formed between the concrete and the hollow concrete pile (1), the adhesiveness is deteriorated, so that the hardening material (8) is injected as necessary. Of course, the hardening material (8) may be injected into the soft layer (6).

When the excavation reaches the support layer (4), the enlarged blades (10) are fully opened to form an enlarged excavation hole (3a), and thereafter, the hardened material (8) is removed from the enlarged excavation hole (3a). ). And
The hollow concrete pile (1) is press-fitted to a predetermined depth, and the two-stage enlarged head (H2) is pulled out from the hollow concrete pile (1) with the expansion blade (10) closed. As a result, the lower end of the hollow concrete pile (1) is embedded and fixed in the bulb block formed by hardening the hardening material (8) formed in the enlarged hole (3a) of the excavation hole (3). become. As a result, the tip of the hollow concrete pile (1) is wrapped in the bulb block, and the hollow concrete pile (1) can be firmly supported by the support layer (4).

Next, the case of on-site construction using the reinforcing bar (1b) will be described. In the case of FIG. 18, one-stage enlarged head
One excavation hole (3) is excavated to the support layer (4) using (H1), and when the excavation is completed, the excavator (A) is pulled out. Then, the drilling hole (3) is filled with hardening material (8) and the reinforcing bar (1b)
Is embedded in the hardening material (8). As a result, a solid cast-in-place pile (1a) is formed.

In the case of FIG. 20, one excavation hole (3) is excavated to the vicinity of the support layer (4) using the two-stage enlarged head (H2), and the excavation blade (10) is fully opened. Then, an enlarged hole (3a) is formed in the support layer (4). Expanded blades fully opened when drilling is completed
Close (10) and then pull out the drilling rig (A). Then, the hardening material (8) is filled in the excavation hole (3), and the reinforcing bar (1b) is embedded in the hardening material (8). Thereby, a cast-in-place pile (1a) having a solid and enlarged bulb portion is formed.

In the case of the on-site construction, the hardening material (8)
Either the filling of the reinforcing bar and the embedding of the reinforcing bar (1b) may be performed first. Also, when excavating the excavation hole (3), if the ground is strong or the excavation depth is shallow and the inner surface of the excavation hole (3) is not likely to collapse, excavation is performed without the casing (K). Is weak or the drilling depth is too deep
When there is a possibility that the inner surface of (3) may be broken on the way, a casing (K) is used. After completion of the excavation, the casing (K) is pulled out of the excavation hole (3). FIGS. 18 and 20 show the construction procedure when the casing (K) is used.

[0073]

According to the present invention, since a hammer mechanism provided in an excavator applies a striking force in the direction of excavation to at least excavate a support layer or an intermediate difficult excavation layer which is difficult to excavate while crushing the support layer. It was possible to pierce difficult layers in a short period of time, and it was possible to quickly cast low-polluting cast-in-place piles as well as hollow concrete piles, which were considered impossible in the past.

At this time, when excavating the support layer and the intermediate difficult excavation layer, the inner diameter of the excavation hole is made larger than the inner diameter of the soft layer,
Tightening of the hollow concrete pile by the support layer and the intermediate difficult excavation layer can be avoided, and the press-fitting of the hollow concrete pile into the excavation hole becomes easier. Further, when the hollow concrete pile is pressed in, the hollow concrete pile can be pressed into the excavation hole with less resistance by rotating the hollow concrete pile.

The injection of the hardening material between the excavation hole and the hollow concrete pile works to enhance the adhesion between the excavation hole and the hollow concrete pile, and enhances the supporting force of the hollow concrete pile.

When the excavating blade of the excavator is expanded in two stages (or in multiple stages), it is possible to excavate with an optimum diameter according to the ground, and the speed of excavation and embedding is realized. Yes, and by forming an enlarged excavation hole in the support layer, the support capacity of the pile can be increased.

[Brief description of the drawings]

FIG. 1 is a sectional front view of a part of a casting device according to the present invention.

FIG. 2 is a schematic enlarged front view of a driving portion of FIG. 2;

FIG. 3 is an enlarged sectional view of the excavator of FIG. 2;

FIG. 4 is a front view when the enlarged blade in FIG. 3 is closed.

FIG. 5 is a front view when the enlarged blade in FIG. 3 is opened.

FIG. 6 is a half sectional view of the one-stage enlarged head of the present invention when the enlarged blade is opened.

7 is a bottom view of the one-stage enlarged head of FIG. 6 when an enlarged blade is opened.

8 is a bottom view of the one-stage enlarged head of FIG. 6 when an enlarged blade is closed.

9 is a cross-sectional view of the one-stage enlarged head of FIG. 6 when the enlarged blade is opened.

FIG. 10 is a bottom view of the two-stage enlarged head of the present invention in a state where an enlarged blade is opened.

FIG. 11 is a perspective view of a main body of the first embodiment of the two-stage enlarged head of the present invention.

FIG. 12 is a perspective view of a main body of a modified example of the first embodiment of the two-stage enlarged head of the present invention.

FIG. 13 is a partial cross-sectional view showing the position of a rotating shaft of a two-stage enlarged head according to the present invention in a fully opened state of an enlarged blade.

FIG. 14 is a partial cross-sectional view showing the position of a rotating shaft of the two-stage enlarged head according to the present invention in which the enlarged blade is in a half-open state;

FIG. 15 is a perspective view of a main body of a second embodiment of the two-stage enlarged head of the present invention.

FIG. 16 is a perspective view of a main body of a modification of the second embodiment of the two-stage enlarged head of the present invention.

FIG. 17 is a sectional view showing a procedure for constructing a hollow concrete pile by the one-stage enlarged head of the present invention.

FIG. 18 is a process cross-sectional view showing a construction procedure of a cast-in-place pile using the one-stage enlarged head of the present invention.

FIG. 19 is a process cross-sectional view showing a construction procedure of a hollow concrete pile using the two-stage enlarged head of the present invention.

FIG. 20 is a process cross-sectional view showing a construction procedure of an in-situ driving pile using the two-stage enlarged head of the present invention.

[Explanation of symbols]

 (A) Drilling rig (a) Drilling part (B) Hammer mechanism (1) Hollow concrete pile (2) Ground (3) Drilling hole (4) Support layer (5) Intermediate difficult excavation layer (6) Soft layer (7) Gap (8) Hardening material

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 000006264 Mitsubishi Materials Corporation 1-5-1, Otemachi, Chiyoda-ku, Tokyo (72) Inventor Tomihiko Oishi 3-2-2, Nakanoshima, Kita-ku, Osaka Kansai Electric Power (72) Inventor Hideo Takenaka 3-3-22 Nakanoshima, Kita-ku, Osaka-shi Kansai Electric Power Co., Inc. (72) Inventor Kazumi Ogura 3-2-2, Nakanoshima, Kita-ku, Osaka Kansai Electric Power Co., Ltd. (72) Inventor Eiji Nakamaru 3-2-22 Nakanoshima, Kita-ku, Osaka-shi Inside Kansai Electric Power Co., Inc. (72) Inventor Kunobu Okada 5--14-10 Nishitenma, Kita-ku, Osaka Kinki Concrete Industry Co. (72) Inventor Ichiro Kobayashi 5-14-10 Nishitenma, Kita-ku, Osaka City Inside Kinki Concrete Industry Co., Ltd. (72) Inventor Wako Soneda Nishiten, Kita-ku, Osaka-shi 5-14-10 Kanki Kinki Concrete Industry Co., Ltd. 501 Machiyamawaki Inside Yokoyama Foundation Co., Ltd. 1528 Naka-Nitta, Yokoi, Kobe-cho

Claims (14)

[Claims] An excavating portion of an excavator is projected from a lower end of an underground hollow concrete pile, and a concrete pile is buried in an excavation hole while excavating the ground below the hollow concrete pile. A method of digging at least a support layer or an intermediate difficult-to-excavate layer, which is difficult to excavate, by crushing the support layer or the intermediate difficult-to-excavate layer by applying a striking force in an excavation direction by a hammer mechanism provided in the excavator Excavation was performed, and the excavated earth and sand was discharged from the gap between the inner surface of the hollow concrete pile and the outer surface of the drilling rig with air injected from the tip of the drilling rig into the bottom of the drilling rig. A method of placing concrete piles, characterized by pushing hollow concrete piles. 2. The method for placing a concrete pile according to claim 1, wherein when digging the support layer or the intermediate difficult digging layer, the inside diameter of the digging hole is made larger than the inside diameter of the soft layer which is easy to dig. A method for placing a concrete pile. 3. The concrete pile driving method according to claim 1, wherein a hardening material for improving the adhesion between the drilling hole and the hollow concrete pile is injected from a tip of the drilling device. How to cast. 4. A concrete pile for digging a hollow concrete pile into an excavation hole while excavating the ground below the hollow concrete pile by projecting an excavated portion of the drilling device from a lower end of the hollow concrete pile for burying underground. A method in which a drilling hole is drilled by applying a striking force in the direction of excavation by a hammer mechanism provided in the excavator and crushing, and in the soft layer, excavation is performed with a diameter substantially equal to the outer diameter of the hollow concrete pile. In the intermediate difficult-to-drill layer and the support layer, the inner surface of the hollow concrete pile and the excavator are excavated with a diameter larger than the outer diameter of the hollow concrete pile, and the excavated earth and sand is injected from the tip of the excavator into the hole bottom. From the gap between the pile and the outer surface of the pile, and push the lower end of the hollow concrete pile into the bottom of the excavated hole. Striking 設方 method of concrete piles, characterized in that for implantation a lower end portion of the hollow concrete pile in the setting material with injecting a hardening material into expansion borehole larger diameter. 5. The method of driving a concrete pile according to claim 1, wherein when the hollow concrete pile is pushed into the excavation hole, the hollow concrete pile is pushed while being rotated. Installation method. 6. A digging device for digging a pit for forming a pile to a predetermined depth, and excavating earth and sand from an end of the digging device to an inner surface of the digging hole and an outer surface of the digging device. This is a method of placing concrete piles by inserting a reinforcing cage into the drilling hole and filling the drilling hole with hardening material for pile formation, after excavation is completed. When excavating the support layer or the intermediate difficult-to-excavate layer, concrete is characterized by excavating while crushing the support layer or the intermediate difficult-to-excavate layer by applying a striking force in the excavation direction by a hammer mechanism provided in the excavator. How to drive a pile. 7. An excavator digs an excavation hole for forming a pile to a predetermined depth from a soft layer to a support layer, and excavates the excavated earth and sand from the tip of the excavator to the bottom of the hole. A concrete pile is poured by removing the soil from the gap between the inner surface and the outer surface of the drilling rig, inserting a reinforced cage into the drilling hole after completion of excavation, and filling the drilling hole with hardening material for pile formation. Therefore, when excavating at least a difficult-to-excavate support layer or an intermediately difficult excavation layer, the excavation is performed while crushing the support layer or the intermediately difficult excavation layer by applying an impact force in the excavation direction by a hammer mechanism provided in the excavator. A method for placing a concrete pile, wherein the excavation is performed at a diameter larger than the hole diameter of the soft layer in the support layer. 8. The method for placing a concrete pile according to claim 1, wherein the excavation is performed by rotating an excavator. 9. A hollow concrete pile for underground burial, a drilling device capable of passing through the inside of a hollow concrete pile, excavating a lower part of the hollow concrete pile to excavate the ground below the hollow concrete pile, and a hollow concrete pile. A press-fitting part for press-fitting the pile into the drilling hole, and a drive part for rotating the drilling rig, wherein the drilling rig is disposed so as to be freely immersed in a radial direction from a protruding part protruding from a lower end of the hollow concrete pile. An installation device for a hollow concrete pile, comprising: an enlarged blade for excavation; a hammer mechanism for applying a striking force in an excavation direction to a ground; a compressed air supply unit; and a hardening material injection unit. 10. The hollow concrete according to claim 9, wherein a rotation locus of a tip of the enlarged blade for excavation has a multistage expanding / contracting function for enlarging or reducing the outer diameter of the hollow concrete pile to substantially the same diameter. Pile driving device. 11. A drill rod attached to the tip of the drill rod,
A drill body having an enlarged blade storage recess formed on a side surface thereof, and a projecting / projecting projection formed in the storage recess via a rotating shaft slidably inserted into a bearing hole formed in the storage recess. 2 composed of wings that can be freely immersed
A step-expanding head, a half-open engaging portion that, when the rotating shaft moves to one side in the bearing hole, rotates the drill rod, and a side surface of the expanding blade abuts to make the expanding blade half-open with respect to the drill body; When the rotation shaft moves to the other side in the bearing hole, and when the drill rod rotates, the side of the enlarged blade comes into contact with the fully opened engaging portion to fully open the enlarged blade with respect to the drill body. A two-stage enlarged head characterized in that it is provided on the inner surface of the head. 12. A two-stage enlarged head according to claim 11, wherein the half-open engagement portion and the full-open engagement portion are provided on the same inner side of the storage recess. 13. The two-stage enlarged head according to claim 11, wherein the half-open engagement portion and the full-open engagement portion according to claim 11 are provided on the inner side opposite to the storage recess. 14. A two-stage enlarged head according to claim 12, wherein the half-opening engagement portion and the fully-opening engagement portion according to claim 12 or 13 are recessed stepwise on the inner surface side.