JPH11200363A - Cast-in-place pile, building method therefor, and steel pipe member with blade used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe member to eliminate a need for removal of earth and facilitate the execution of earth, and moreover to provide a cast-in- place pile having a high tip support force, a work executing method, and a steel pipe member with a blade used therein. SOLUTION: A steel pipe member 1 with a blade comprises a steel pipe pile 2 consisting of a short pipe 3 on which a blade 20 is mounted in an inclination state; and a casing 10 coupled to the steel pipe pile 2 through a coupling means transmissibly of torque axially removable. After the steel pipe member 1 with a blade is screwed in a ground and buried, a reinforcing bar or a concrete pile is erected in the steel pipe member 1 with a blade, concrete or a curing agent is placed or injected, and the casing 10 is pulled out for creating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast-in-place pile, a method of constructing the same, and a winged steel pipe member used for the method.

[0002]

2. Description of the Related Art In a conventional cast-in-place pile, a hole must be dug in the ground in some way in order to form a pile, a reinforcing bar is buried in the formed hole, and concrete is poured.
A pile was being created. As a method of digging such a hole, a method of protecting the entire digging surface with a casing, such as a deep foundation method or a Venoto method, or a method of digging a hole, such as an earth drill method, a reverse method, a BH method, or the like. There is one that protects only the upper part of the hole, and protects the hole wall by the hydraulic pressure of the bentonite muddy water or fresh water from the deeper part.

In the above-mentioned construction method, (1) the construction can be performed with low noise and low vibration. (2) A long pile can be constructed by penetrating the middle hard stratum. (3) The strength and length of the pile can be adjusted without waste. And the like. Further, in the case of the cast-in-place pile whose bottom end is expanded, the supporting force can be increased by the expanded diameter. In addition, these cast-in-place piles can be constructed with low noise and low vibration, unlike the driven piles, and are therefore suitable for construction in urban areas.

[0004]

The conventional cast-in-place pile method has the above advantages, but has the following problems. (1) Excavated earth and sand must be treated as industrial waste. (2) There are various problems with the quality of the pile, such as collapse of the hole wall during construction, slime treatment of the tip, and concrete strength. (3) In the case of expanded piles, it is made of concrete,
If bending occurs at the end of the expanded bottom, cracks etc. will occur,
There is a problem that the supporting force is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is a cast-in-place pile that has no soil removal, is easy to construct, and has a large supporting capacity at the tip, a method of constructing the pile, and a blade used therefor. It is intended to obtain a steel pipe member with a hole.

[0006]

(1) A cast-in-place pile according to the present invention comprises a steel pipe pile composed of a short pipe having wings inclined and mounted, and a shaft capable of transmitting torque to the steel pipe pile by connecting means. A winged steel pipe member consisting of a casing detachably connected in the direction, and screwing the winged steel pipe member into the ground to bury the steel pipe member, and then laying a reinforcing steel bar or a concrete pile in the winged steel pipe member to concrete. Or cast a solidifying agent,
Alternatively, it is formed by injecting and pulling out the casing. (2) A steel pipe was attached to a portion of the pile head that contributed to the horizontal resistance in (1).

(3) The method for constructing a cast-in-place pile according to the present invention is characterized in that a steel pipe pile consisting of a short pipe with wings inclined is attached, and torque can be transmitted to the steel pipe pile by connecting means and the pipe can be attached and detached in the axial direction. A step of screwing and embedding a winged steel pipe member composed of a casing connected as possible, embedding a reinforcing bar or a concrete column in the winged steel pipe member, and embedding the reinforcing bar or concrete pile. It comprises a step of casting or pouring concrete or a solidifying agent into the winged steel pipe member, and a step of pulling out the casing during or after the casting of the concrete or the like. (4) After the casing (3) was pulled out, a steel pipe was attached to a portion of the pile head that contributed to the horizontal resistance. (5) Further, at the time of pulling out the casing of the above (3), the lower end portion is held at a portion contributing to the horizontal resistance of the pile head, and the upper portion is cut off.

(6) The winged steel pipe member according to the present invention is characterized in that a steel pipe pile having a wing inclined at or near the tip end of a short pipe, the outer diameter of which is substantially equal to the outer diameter of the steel pipe pile, And a casing connected to the steel pipe pile so as to transmit torque and to be detachable in an axial direction. (7) The short pipe and the casing of the above (6) are made of a square steel pipe. (8) At least the casing of (6) is made of a steel pipe with ribs.

(9) One or a plurality of spiral wings or flat wings are attached to the tip of the short pipe of (6), (7) or (8) or to the tip and the outer peripheral surface to form one or more stages. The wings of the steps were constructed. (10) One or more spiral blades or flat blades are attached to the outer peripheral surface of the casing of (6), (7), (8) or (9) to form one or more stages of blades. . (11) The spiral wing or flat wing of (9) or (10) is formed in a polygonal shape.

[0010]

FIG. 1 is a perspective view of a winged steel pipe member used for a cast-in-place pile according to the present invention. In the drawing, reference numeral 1 denotes a steel pipe member with a wing, 2 denotes a steel pipe pile constituting the steel pipe member 1 with a wing, and a relatively short steel pipe (hereinafter referred to as a short pipe) 3 and a wing provided at a tip end of the short pipe 3. 2
It consists of 0. Reference numeral 10 denotes a steel pipe which also serves as a casing (hereinafter referred to as a casing) whose outer diameter is substantially equal to the outer diameter of the short pipe 3, and which transmits torque to the steel pipe pile 2 by connecting means described later, but is connected detachably in the axial direction. I have.

At the tip of the short tube 3, as shown in FIG.
A screw-shaped mounting portion 4 cut off in a spiral shape is provided, and the height h of the step portion 4a forming the mounting portion 4 is:
Although it depends on the condition of the ground where the winged steel pipe member 1 is buried (therefore, a cast-in-place pile is formed), the outer diameter D of the short pipe 3, and the like, generally h = 0.1 to 0.6D (D is the short pipe 3). Is preferable. When the height h of the stepped portion 4a is less than 0.1D, the penetration amount per rotation of the bladed steel pipe member 1 decreases, and when it exceeds 0.6D, the penetration amount per rotation becomes too large. Therefore, the torque for rotating the winged steel pipe member 1 becomes excessively large, and the depth of the ground excavated by the spiral plate 21 becomes large, so that the supporting force is slightly reduced.

The length L of the short pipe 3 varies depending on the condition of the ground on which the cast-in-place pile is formed, the outer diameter D of the short pipe 3, and the like, but it is generally about L = 0.5 to 4D. desirable. The height h of the step 4a and the length L of the short tube 3
Is the same in other embodiments. In addition, short pipe 3
Is made of steel pipe, but for example, the casing 1
One end of a steel plate having the same length as the circumferential length of 0 may be cut obliquely, bent and formed into the same outer diameter as the casing 10, and the butt portion may be welded to form the short pipe 3. .

As shown in FIG. 3, the wing 20 is provided with a hole 20b at the center of a circular steel plate 20a having an outer diameter D ₁ (for example, D ₁ = 2D) larger than the outer diameter D of the short tube 3 or an oval steel plate. Then, a portion between the hole 20b and the peripheral portion is cut at one place, and is bent into a shape corresponding to the shape of the mounting portion 4 of the short pipe 3 to form a spiral wing 21, and the spiral wing 21 is formed. The short pipe 3 is mounted on the mounting portion 4 by welding. The size of the spiral wing 21 varies depending on the condition of the ground in which the winged steel pipe member 1 is embedded, the outer diameter of the short pipe 3, and the like, but is generally about 1.5 to 3 times the outer diameter D of the short pipe 3. Is desirable (below,
The same applies to each embodiment.)

Next, referring to FIG.
The configuration of the connecting portion, which is a connecting means for connecting to zero, is described.
Reference numeral 5 denotes a plurality of locking shafts protruding radially above the inner wall of the short pipe 3 (two cases are shown in the figure). Reference numeral 11 denotes a fitting portion formed at the lower end of the casing 10 by reducing the outer diameter of the short pipe 3 to the inner diameter or less.
As shown in FIG. 4B, an engagement portion 12 that fits into the locking shaft 5 provided on the short tube 3 is provided.

In the connecting portion configured as described above,
The fitting part 11 provided on the casing 10 is connected to the short pipe 3 of the steel pipe pile 2.
And the engaging portion 12 is locked to the locking shaft 5. Thus, when the casing 10 is rotated, the torque is transmitted to the steel pipe pile 2 to rotate it. When the casing 10 is pulled up, the steel pipe pile 2 is left at that position, and only the casing 10 is pulled up.

Further, as shown in FIG. 4C, a T-shaped engaging portion 13 may be provided in the fitting portion 11 of the casing 10, and in this case, the engaging portion 13 is When the casing 10 is rotated after being fitted to the
And transmits the torque to the steel pipe pile 2. Although the engaging portion 13 cannot be disengaged from the locking shaft 5 even if the casing 10 is pulled up in this state, the casing 10 is detached from the steel pipe pile 2 by rotating the casing 10 slightly in the opposite direction and pulling up. can do. Although not shown, the fitting portion 11 may be provided with an inverted L-shaped engaging portion instead of the engaging portions 12 and 13.

FIG. 5 shows another example of the connecting portion, in which a female screw 6 is provided on the short pipe 3 of the steel pipe pile 2 and a screw 14 is provided on the fitting portion 11 of the casing 10. is there. Thus, when the casing 10 is rotated in one direction, the male screw 14 is screwed into the female screw 6 of the steel pipe pile 2 to connect them together, and by further rotating the casing 10 in the same direction, torque is applied to the steel pipe pile 2. Can be transmitted. The casing 10 can be detached from the steel pipe pile 2 by rotating the casing 10 in the other direction.

In the example shown in FIGS. 4 and 5, the short pipe 3 of the steel pipe pile 2 is provided with the locking shaft 5 or the female screw 6 and the fitting portion 11 of the casing 10 is provided with the locking portions 12 and 13 or the male screw 14. Is shown, but the locking shaft 5 or the female screw 6 is connected to the casing 1.
0, and the locking portions 12, 13 or the male screw 14 are connected to the steel pipe pile 2
May be provided on the short pipe.

FIGS. 6 to 8 show still another example of the connecting portion. In the example of FIG. 6, a plurality of ribs 7 are provided on the inner wall of the short pipe 3 of the steel pipe pile 2 and the inner wall of the casing 10 is provided. Locking piece 15 extending downward at the lower end of the
, Whereby the torque of the casing 10 is transmitted to the steel pipe pile 2 and is detachable in the axial direction.

In the example of FIG. 7, for example, a cross-shaped locking frame 8 is attached to the upper part of the short pipe 3 of the steel pipe pile 2, and a plurality of locking pieces 15 are provided on the casing 10 as in the example of FIG. This allows
The connecting portion is capable of transmitting torque and is detachable in the axial direction. In the example of FIG. 8, the plurality of pipes 9 are attached to the inner wall of the short pipe 3 of the steel pipe pile 2 and the casing 1
A rod 16 that fits into the pipe 9 is attached to the inner wall at the lower end of the cylinder 0 to form a connecting portion capable of transmitting torque and detachable in the axial direction.

In the example of FIGS. 6 to 8 described above, the short pipe 3 of the steel pipe pile 2 is provided with the rib 7, the locking frame 8 or the pipe 9, and the locking piece 15 or the locking piece 15 which is locked or fitted into the casing 10 is provided. Bar 1
6, the rib 7, the locking frame 8 or the pipe 9 is provided on the casing 10, and the locking piece 15 or the bar 16 is provided.
May be provided on the short pipe 3 of the steel pipe pile 2. In addition, although the case has been described in which the locking shaft 5 and the like of the connecting portion as these connecting means are provided on the inner wall of the short tube 3 and the casing 10, they may be provided on the outer wall. However, since the ground on the outer peripheral surface of the winged steel pipe member 1 may be disturbed at the time of screwing as compared with the case where it is provided on the inner wall, there is a possibility that the supporting force may be reduced. Although the configuration of the connecting portion as the connecting means has been described with reference to FIGS. 4 to 8, the present invention is not limited to this, and any other components that can transmit torque and can be attached and detached in the axial direction can be used. May be used.

Next, a method of constructing a cast-in-place pile using the cast-in-place pile member 1 will be described. (1) First, for example, the steel pipe pile 2 and the casing 10 are connected by the connecting means as described above to form the winged steel pipe member 1.

(2) Next, as shown in FIG. 9, an auger 51 mounted on a base machine 50 has a winged steel pipe member 1 attached thereto.
Connect the pile heads. When the auger 51 is rotated, the rotation is transmitted to the casing 10, the torque is transmitted to the steel pipe pile 2 via the connecting portion, and the winged steel pipe member 1 is screwed into the ground by the screw action of the wing 20. It is buried (step 1). At the time of screwing, since the gap on the lower surface of the wing 20 is small, soil and sand hardly penetrate into the winged steel pipe member 1. The state at this time is shown in FIG.

(3) Next, as shown in FIG. 10 (b), a reinforcing bar 18 is erected in the steel pipe member 1 with wings (step 2), and concrete 19 is cast therein (step 3). (4) And before the concrete 19 solidifies,
As shown in FIG. 0 (c), the casing 10 is pulled out (step 4). When pulling out the casing 10, the casing 10 may be pulled up while rotating the casing 10 in the reverse direction by the auger 51, or the casing 10 may be pulled up to some extent by a power jack or the like, and then pulled out with a crane. If the casing 10 is pulled out while the concrete 19 is cast, the casing 10 can be pulled out more easily because the resistance due to the concrete 19 is small. Also, the extracted casing 10 can be reused.

As a result, as shown in FIG.
The steel pipe pile 2 is left at that position, and a concrete pile P having the steel pipe pile 2 as a pile tip can be formed.

[Embodiment 2] FIG. 11 shows a method for constructing a cast-in-place pile according to Embodiment 2 of the present invention. Steps 1 to 3 of the present embodiment are the same as those of the first embodiment (FIGS. 10A and 10B), and a description thereof will be omitted. In the present embodiment, when the casing 10 is pulled out during or after the concrete 19 is poured, the casing 10 is not completely removed, and as shown in FIG. FIG. 11 shows a state in which the portion contributing to the horizontal resistance is pulled up and held at that position.
As shown in (d), the portion above the pile head is cut (step 5), and the casing 10 (steel pipe) is left in a portion that contributes to horizontal resistance, and is reinforced. After the casing 10 is completely pulled out, a steel pipe may be attached to a portion of the concrete pile P that contributes to the horizontal resistance of the pile head.

When the concrete pile P (cast-in-place pile) constructed according to the first and second embodiments is constructed, the winged steel pipe member 1 is put into the ground because the wing 20 protrudes greatly from the outer peripheral surface. When the blade is screwed, the wings 20 bite into the ground below and screw the winged steel pipe member 1 into the ground, and excavate earth and sand below the winged steel pipe member 1 at a staggered portion and extrude it around the winged steel pipe member 1. , And a function of compressing it. Therefore, the winged steel pipe member 1 can be screwed into a hard layer, and earth and sand are not discharged to the outside.

After the construction, since the steel pipe pile 2 having the wings 20 is left underground as a pile tip, when functioning as a pile for supporting a vertical load by an overlying building or the like, the wings 20 are It functions in the same way as the expanded bottom of a concrete pile, and can obtain a large ground support force. For example, if the size of the wings 20 is about twice the outer diameter of the short pipe 3, the area of the tip of the pile is about four times that without the wings 20, and a very large ground support force can be obtained.

Further, according to the present invention, it is not necessary to dig a hole in the ground in advance, so that there is no problem of earth removal processing or collapse of the hole wall, and the tip of the pile is made of steel wings. As a result, the supporting force does not decrease due to cracks or the like.

[Embodiment 3] FIG. 12 shows a method of constructing a cast-in-place pile according to Embodiment 3 of the present invention. Also in this embodiment, the work (step 1) until the winged steel pipe member 1 is buried in the ground is the same as in the case of the first embodiment, and a description thereof will be omitted. In the present embodiment, as shown in FIG. 12 (b), a ready-made concrete pile 18a is built in the winged steel pipe member 1 buried underground (step 2).
A solidifying agent 19a such as cement milk is injected into the surroundings (Step 3), and the casing 10 is withdrawn while the solidifying agent 19a is injected or before the injection is completed and solidified (Step 4). .

As a result, as shown in FIG.
The steel pipe pile 2 is left at that position, and a concrete pile P having the steel pipe pile 2 as a pile tip can be formed. The operation and effects of the present embodiment are almost the same as those of the first embodiment, but the labor of assembling the reinforcing bars and the like at the site can be omitted.
Labor saving and workability can be improved. In addition,
Also in the present embodiment, as in the case of the second embodiment, when the casing 10 is pulled out, a part thereof may be left on the pile head, or another steel pipe may be fitted.

Embodiment 4 Next, various embodiments of the cast-in-place pile according to the present invention and the winged steel pipe member 1 used in the method of constructing the pile will be described. Note that the connection between the steel pipe pile 2 and the casing 10 uses the connection device described with reference to FIGS. 4 to 8 as appropriate, and a description thereof will be omitted. FIG. 13 is a perspective view of the fourth embodiment, in which two stages of wings 20 and 30 are provided on the short pipe 3 constituting the steel pipe pile 2. As shown in FIG. 14, the wing 20 provided at the lower end of the short pipe 2 (hereinafter referred to as a lower wing) has an outer diameter D ₂ (for example, larger than the outer diameter D of the short pipe 3).
D ₂ = 2D) is attached to the mounting portion 4 of the short pipe 3 with the semicircular flat blades 21a and 21b formed by dividing a circular steel plate or an elliptical steel plate into two parts from the center, with their linear edges approaching each other. It is configured.

The wing 30 (hereinafter referred to as an upper wing) is shown in FIG.
The flat edges of the flat blades 21a, 21b are cut off (or a ring-shaped steel plate is cut off as shown by a broken line) in accordance with the outer diameter of the short pipe 3.
It is attached to the outer peripheral surface of the short pipe 3 by welding in accordance with the inclination angle of the lower blade 20 above the lower blade 20. The spiral blade 2 shown in the first embodiment may be attached to one or both of the lower blade 20 and the upper blade 30.
1 may be attached. When the spiral wing is attached to the upper stage wing 30, the outer diameter D of the short pipe 3 is placed at the center of the steel plate 20a in FIG.
A spiral wing may be formed by forming a hole having a size substantially equal to the above and bending the hole. Further, the upper wing 30 may be provided in two or more stages.

In this embodiment, substantially the same effects as those in the first and second embodiments can be obtained. However, since the steel pipe pile 2 is provided with two or more blades 20 and 30, the propulsion force at the time of screwing is reduced. This improves the workability and the ground support capacity. Further, when one or both of the lower wing 20 and the upper wing 30 are formed of flat wings, manufacturing and mounting are easy, so that the cost can be reduced.

[Embodiment 5] FIG. 15 is a perspective view of a winged steel pipe member 1 according to this embodiment. In the present embodiment, as shown in FIG. 16, the lower end of the short pipe 3 constituting the steel pipe pile 2 (in FIG.
Are turned upside down), and are provided with lenticular-shaped mounting portions 4b and 4c, each of which is spirally cut off. In this case, the height h ₁ of the step portion 4d is half the height h of the step portion 4a of the first embodiment shown in FIG. Note that three or more attachment portions 4b and 4c may be provided.

The wings 20 attached to the attachment portions 4b and 4c of the short pipe 3 are, for example, square steel plates 2 as shown in FIG.
Square plate blades 22a and 22b obtained by dividing the center 2 into two from the center
It has a very simple structure. The combined size of the flat blades 22a and 22b is
Although it depends on the state of the ground for forming the cast-in-place pile P, the outer diameter of the short pipe 3, and the like, generally, the outer diameter D of the short pipe 3 is 1.5 to 1.5 or more.
It is preferably about 3.0 times. Here, the flat blades 22a, 22
The size of b means the length L of the diagonal line of the steel plate 22 shown in FIG.

The function of the winged steel pipe member 1 according to the present embodiment is almost the same as that of each of the above-described embodiments, but in this embodiment, when the winged steel pipe member 1 penetrates into the ground, The side faces in the direction of excavation rotation are flat blades 22a, 2
Since it is formed by the corners (maximum size part) of 2b,
The rear side of the tip surface tends to move away from the excavated ground. That is, the flat blades 22a and 22b have a flank behind the excavated portion. For this reason, the friction resistance at the time of penetration can be reduced as compared with a steel pipe pile having an outer circumferential arc-shaped wing in which the side surface at the rear of the excavated portion constantly contacts the excavated ground wall surface.

FIG. 18 shows another example of the present embodiment. In this example, a triangular flat plate obtained by cutting a square steel plate by a diagonal line and dividing it into two parts instead of the square flat plate blades 22a and 22b. The blades 22 c and 22 d are attached to the tip of the short tube 3. The function of this example is almost the same as that of the example of FIG.

FIG. 19 shows still another example of this embodiment. In this example, the flat blades 22e and 22f are formed by dividing a hexagonal steel plate into two. The function of this example is also shown in FIG.
Is substantially the same as in the case of the above example, but by making the wing 20 closer to a circle, the penetration into the ground becomes smooth.

In the above description, the case where the plate blades 22a to 22f are formed by dividing a triangular, quadrangular or hexagonal steel plate into two parts is shown. For example, an eight-sided or more polygonal steel plate is divided into two parts. You may comprise a flat wing. Further, in the above description, the case where the flat plate blade is formed by dividing the polygonal steel plate into two is shown. However, the flat plate blade is formed by dividing it into three or more portions, and this is provided at the tip of the short pipe 3. May be sequentially mounted on the mounting portion. Further, although not shown, the spiral blade 21 described in the first embodiment may be formed in a polygonal shape.
Also in the present embodiment, the upper stage wing may be configured by attaching a substantially semicircular or polygonal flat wing or a spiral wing to the outer peripheral surface of the short tube 3 above the wing 20.

[Embodiment 6] FIG. 20 is a perspective view of this embodiment. In the present embodiment, a winged steel pipe member 1 is formed by using a square steel pipe for a short pipe 3a and a casing 10a of a steel pipe pile 2, and a square steel pipe is used instead of a normal steel pipe (round). This is the same as the winged steel pipe member 1 of the first embodiment. The size D of the short tube 3a in the present embodiment
(Corresponding to the outer diameter of the short pipe 3 in the first embodiment) refers to the length of the diagonal line of the rectangular steel pipe.

The function of the winged steel pipe member 1 according to the present embodiment is almost the same as that of the winged steel pipe member 1 of the first embodiment, except that the short pipe 3 and the casing 10 are ordinary steel pipes (round).
In the case of the winged steel pipe member 1 consisting of: when screwed in, as shown in FIG. 21A, the entire peripheral surface of the short pipe 3 and the casing 10 is in sliding contact with the ground, so that the peripheral surface friction is large,
Requires large torque. On the other hand, when these are made of square steel pipes, as shown in FIG.
When screwing, mainly the short pipe 3a and the casing 1
Since the corner of Oa is in contact with the ground on the peripheral surface, the peripheral friction is small, so that the screwing torque can be reduced.

[Seventh Embodiment] FIG. 22 is a perspective view of the present embodiment. In this embodiment, the casing 10b constituting the winged steel pipe member 1 is formed of a ribbed steel pipe. That is, a steel plate having a plurality of ribs provided on the surface is bent by rolling, for example, to form spiral ribs 17 on the outer peripheral surface. The pitch P of this rib 17
Is approximately the same as the height h of the step portion 3a of the mounting portion 3 provided on the short pipe 3 of the steel pipe pile 2 of the first embodiment. The steel pipe pile 2 has the same configuration as in the first to fifth embodiments. However, the mounting portion 4 provided at the tip of the short pipe 3 is formed at an angle substantially equal to the inclination angle of the rib 17. Further, the short pipe 3 may be formed of a ribbed steel pipe having a rib having substantially the same angle as the rib 17 of the casing 10b.

The function of the winged steel pipe member 1 according to the present embodiment is also substantially the same as the function of the winged steel pipe member 1 of the first embodiment, but the spiral rib 17 also contributes to propulsion when screwed into the ground. Therefore, the driving force can be improved. When the casing 10b is pulled out during or after the concrete 19 or the like is poured, the casing 10b can be pulled out extremely easily by rotating the casing 10b in a direction opposite to the screwing.

[Eighth Embodiment] FIG. 23 is a perspective view of the present embodiment. In this embodiment, a wing 40 (hereinafter, referred to as an auxiliary wing) is provided on a casing 10 constituting the winged steel pipe member 1. This auxiliary wing 40 is, for example, a second embodiment.
A flat blade 41 having the same structure as the flat blades 31a and 31b constituting the upper blade 30 provided on the short pipe 3 of the steel pipe pile 2 (FIG. 13).
a and 41b are attached to the outer periphery of the casing 10 at the same angle as the angle of the attachment portion 4 provided on the short pipe 3 of the steel pipe pile 2. The auxiliary wing 40 may be constituted by a spiral wing or a polygonal flat wing, or may be provided in the casing 10 in a plurality of stages.

Although the function of the present embodiment is almost the same as that of the first embodiment, in the present embodiment, the casing 1
Since the auxiliary wings 40 are provided at 0, the force for pushing down the winged steel pipe member 1 at the time of construction increases, so that it is possible to prevent or reduce the rotation from entering the hard stratum. After the concrete 19 or the like is cast, the casing 1
When the casing 10 is pulled out, the casing 10 can be easily pulled out by rotating the casing 10 in a direction opposite to that at the time of screwing, by the screw action of the auxiliary wing 40. This embodiment can be implemented in each of the above-described embodiments.

[Embodiment 9] The steel pipe pile 2 forming the tip of the cast-in-place pile P (hereinafter, the cast-in-place pile P of Embodiment 1) is formed by a spiral forming the wing 20. Since the wings 21 receive a large ground reaction force, high rigidity is required. For example, the outer diameter D of the short pipe 3 is 500
mm and the size of the spiral blade 21 is about 1000 mm, a large bending moment is generated in the spiral blade 21 due to the ground reaction force. For this reason, it is required in design to use the spiral blade 21 having a thickness of about 40 mm, and this bending moment is transmitted to the short pipe 3 of the steel pipe pile 2 to generate a large bending stress.

Depending on the relationship between the size of the short tube 3 and the size of the spiral wing 21 and the distribution of the ground reaction force, a large imbalance occurs in the bending moment applied to the inside and outside of the short tube 3. , As shown in FIG.
It is conceivable that a large bending moment is transmitted to the short pipe 3.

In this embodiment, as shown in FIG. 25, a short pipe 3 constituting a steel pipe pile 2 is made of a steel material or a steel pipe thicker than a normal steel pipe or a steel material or a steel having a strength larger than that of a normal steel pipe. The short tube 3 is made of a steel pipe, and the spiral wing 2
The bending stress generated in the short pipe 3 by attaching the flat blade 1 or the flat blade is kept within the allowable stress.

The wall thickness of the short pipe 3 as described above is determined by numerical analysis in consideration of the assumed ground reaction force. For example, when the outer diameter of the short pipe 3 is 500 mm, the size of the spiral blade 21 is 1000 mm, and a vertical load of 500 t is applied, in a normal steel pipe, 14 mm is applied to a portion where only axial force is applied.
When the thickness is within the yield stress (2400 kgf / cm ² ), a thickness of about 20 mm is required in order to keep the stress at the portion where the axial force and bending moment act within an allowable value. The present embodiment can sufficiently cope with a large ground reaction force by increasing the thickness of the short pipe 3 or using a steel material having a large strength. Note that this embodiment can be implemented in each of the above-described embodiments.

[Embodiment 10] As the outer diameters of the steel pipe pile 2 and the casing 10 increase, the outer diameter of the wing 20 also increases as described above, and accordingly, the thickness of the wing 20 also increases.
As a result, for example, as shown in FIG.
When the winged steel pipe member 1 is screwed into the ground, large resistance due to the ground is applied to the end of the flat wing or the spiral wing on the rotation direction side, and if the torque is weak, it becomes impossible to rotate and cannot penetrate the ground. There is. For this reason, there arises a problem that the base machine 50 must be enlarged. In the present embodiment, in order to solve such a problem, the cut-in portion (end in the rotation direction) of the flat blade or the spiral wing of each embodiment is cut at an acute angle to provide an inclined surface, whereby the end surface is provided. The resistance of the ground applied to the part is reduced, and it is easy to penetrate into the ground to reduce the torque. Note that, instead of the inclined surface, a digging blade for assisting digging may be attached to the biting portion of the flat blade or the spiral wing.

[Embodiment 11] In this embodiment, when the winged steel pipe member 1 is screwed into the ground and buried, the flat wing or the spiral wing is prevented from being deformed. The reinforcing member is attached to the biting portion of the wing.

[Example] Next, an example of the present invention will be described with reference to an example of a construction test in which a cast-in-place pile is formed using the winged steel pipe member 1 according to the first embodiment. Steel pipe member with wing 1
Has a total length of 45 m, and the short pipe 3 of the steel pipe pile 2 constituting the same has an outer diameter D: 500 mm, a length L: 1000 mm, and a wall thickness t20 m.
m, the step h of the mounting portion 4 of the wing 20 is 0.125D (62.
5 mm), the outer diameter D ₁ of the spiral wing 21: 1000 mm,
The plate thickness was 40 mm. The casing 10 has an outer diameter of 500 mm, a length of 40 m, and a thickness of 9 mm. The connection between the steel pipe pile 2 and the casing 10 is the same as that shown in FIGS. 4A and 4B in the first embodiment. Means were used.

For the construction, the base machine 5 shown in FIG.
The rotation force was transmitted to the pile head of the steel pipe member 1 with wings by the auger 51 mounted on the wing. The ground at the test site was a landfill soil up to 8 m from the surface of the ground, a soft clayey soil having an N value of about 2 from 8 m to 40 m, and a firm fine sand layer having an N value of 50 or more at a depth of 40 m or less. The cast-in-place pile member 1 to which the rotational force was applied was able to be buried to a predetermined depth smoothly in a short time.

Next, a reinforcing bar 18 was installed in the casing 10 and the steel pipe pile 2 from the upper end opening of the casing 10, and concrete 19 was poured into the casing 10 and the steel pipe pile 2. Then, before the concrete 19 is solidified, the casing 10 is slightly raised by the auger 51 to disengage the connecting means, and then the casing 10 is raised by the auger 51 while rotating the casing 10 in a direction opposite to the direction of screwing. , A cast-in-place pile P provided with the steel pipe pile 2 having the wings 10 at the tip of the pile could be formed.

[0056]

(1) The cast-in-place pile according to the present invention is configured such that torque can be transmitted to the steel pipe pile by connecting means and that it can be detachably mounted in the axial direction. It has a steel pipe member with a wing consisting of a connected casing, and after screwing this steel pipe member into the ground and burying it, a reinforcing bar or a concrete pile is built in the steel pipe member with a wing and a concrete or a solidifying agent is poured. Alternatively, since the casing is formed by injecting and pulling out the casing, there is no earth removal at the time of forming, so that the construction is easy and the cost can be reduced. Further, since the pile tip is constituted by a steel pipe pile having wings, a cast-in-place pile having a large tip supporting force can be obtained.

(2) Since a steel pipe is mounted on the pile head of the cast-in-place pile of the above (1) and strengthened, a cast-in-place pile having a large resistance to the horizontal force applied to the pile head is obtained. Can be.

(3) The method for constructing a cast-in-place pile according to the present invention is characterized in that a steel pipe pile consisting of a short pipe with its wings inclined is attached, and torque can be transmitted to the steel pipe pile by connecting means and detachable in the axial direction. Screwing and embedding a winged steel pipe member consisting of a casing connected to the ground, laying a reinforcing steel bar or a concrete column in the winged steel pipe member, and winged steel pipe having a reinforcing steel bar or concrete pile embedded therein Since it consisted of a step of casting or pouring concrete or a solidifying agent into the member, and a step of pulling out the casing during or after the placement of concrete, screw the winged steel pipe member to a hard layer and bury it. This makes it possible to create cast-in-place piles that reach a solid layer. In addition, since concrete and the like are cast into the casing made of steel pipe, problems such as collapse of the borehole wall do not occur, and the casing can be reused. Since there is no construction, construction is easy and cost can be reduced.

(4) After the casing is pulled out in (3), the pile head is reinforced by attaching a steel pipe to a portion contributing to the horizontal resistance, so that the pile head has a large resistance against the horizontal force applied to the pile head. You can get cast-in-place piles. (5) Further, when the casing is pulled out in the above (3), the lower end is held at a portion contributing to the horizontal resistance of the pile head, and the upper portion is cut off, so that the steel pipe can be easily attached to the pile head. Can be installed.

(6) The steel pipe member with wings according to the present invention comprises a steel pipe pile having a wing inclined at or near the tip of a short pipe, an outer diameter substantially equal to the outer diameter of the steel pipe pile, (1) or (3) because the stake is constituted by a casing capable of transmitting torque and being detachably connected in the axial direction.
Cast-in-place piles can be easily formed at low cost.

(7) Since the short pipe and the casing of the above (6) are made of a square steel pipe, the screwing torque of the steel pipe member with blades can be reduced. (8) Since at least the casing of (6) is made of a ribbed steel pipe and the rib contributes to screwing the winged steel pipe member into the ground, the propulsive force of the winged steel pipe member increases. Further, when the casing is pulled out, a pulling force by the ribs can be obtained, and the work becomes easy.

(9) One or more spiral wings or flat wings are attached to the tip of the short pipe of (6), (7) or (8) or to the tip and the outer peripheral surface to form one or more stages. Since the stepped blade is formed, the bladed steel pipe member can be screwed into a hard layer. Further, when the spiral wing is attached, the workability is improved, and when the flat wing is attached, the production and the attachment are easy, and the cost can be reduced. Further, when a plurality of stages of blades are provided, the propulsion force increases, so that even when the stratum is hard, the steel tube member with the blades can be prevented from turning around.

(10) One or more spiral blades or flat blades are attached to the outer peripheral surface of the casing of (6), (7), (8) or (9) to form one or more stages of blades. With this configuration, substantially the same effects as in the case of (9) can be obtained, and at the time of drawing, the pulling force by the wings can be obtained, so that the work becomes easy. (11) Since the spiral wing or flat wing of (9) or (10) is formed in a polygonal shape, the effect of (9) can be obtained, and the frictional resistance can be reduced when the winged steel pipe member is screwed. Can be.

[Brief description of the drawings]

FIG. 1 is a perspective view of a winged steel pipe member according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view of the short tube of FIG. 1;

FIG. 3 is an explanatory view of the spiral blade of FIG. 1;

FIG. 4 is an explanatory view of an example of a connecting portion for connecting the steel pipe pile and the casing of FIG. 1;

FIG. 5 is an explanatory view of another example of a connecting portion connecting the steel pipe pile and the casing of FIG. 1;

FIG. 6 is an explanatory view of another example of the connecting portion for connecting the steel pipe pile and the casing of FIG. 1;

FIG. 7 is an explanatory view of another example of the connecting portion for connecting the steel pipe pile and the casing in FIG. 1;

FIG. 8 is an explanatory diagram of another example of a connecting portion that connects the steel pipe pile and the casing of FIG. 1;

FIG. 9 is an explanatory diagram of construction according to the first embodiment.

FIG. 10 is an explanatory diagram illustrating a construction method according to the first embodiment.

FIG. 11 is an explanatory diagram illustrating a construction method according to a second embodiment of the present invention.

FIG. 12 is an explanatory diagram illustrating a construction method according to a third embodiment of the present invention.

FIG. 13 is a perspective view of a cast-in-place pile member according to Embodiment 4 of the present invention.

FIG. 14 is an explanatory view of the flat blade of FIG. 13;

FIG. 15 is a perspective view of a winged steel pipe member according to Embodiment 5 of the present invention.

FIG. 16 is a perspective view of the short tube of FIG. 15;

FIG. 17 is an explanatory view of the flat blade of FIG.

FIG. 18 is a perspective view of another example of the fifth embodiment.

FIG. 19 is a perspective view of another example of the fifth embodiment.

FIG. 20 is a perspective view of a winged steel pipe member according to Embodiment 6 of the present invention.

FIG. 21 is an operation explanatory view of FIG. 20;

FIG. 22 is a perspective view of a winged steel pipe member according to a seventh embodiment of the present invention.

FIG. 23 is a perspective view of a winged steel pipe member according to Embodiment 8 of the present invention.

FIG. 24 is an explanatory diagram of a stress distribution due to a ground reaction force applied to a wing.

FIG. 25 is a partial cross-sectional perspective view of a winged steel pipe member according to Embodiment 9 of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Steel pipe member with wings 2 Steel pipe pile 3 Short pipe 4, 4b, 4c Mounting part 4a Stepped part 10 Casing (steel pipe) 10a Casing (square steel pipe) 10b Casing (ribbed steel pipe) 20 Blade (lower wing) 21 Spiral wing 21a , 21b, 22a to 22f, 31a, 31b, 4
1a, 41b Flat wing 30 wing (upper wing) 40 wing (auxiliary wing) P Cast-in-place pile

Claims (11)

[Claims] 1. A winged steel pipe member comprising: a steel pipe pile formed of a short pipe having wings attached at an angle; and a casing connected to the steel pipe pile by a connecting means so as to transmit torque and to be detachable in an axial direction. The winged steel pipe member is screwed into the ground and buried, and then a reinforcing bar or a concrete pile is built in the winged steel pipe member, concrete or a solidifying agent is poured or poured, and the casing is pulled out and formed. Cast-in-place piles characterized by the following. 2. The cast-in-place pile according to claim 1, wherein a steel pipe is attached to a portion of the pile head that contributes to horizontal resistance. 3. A steel pipe pile comprising a short pipe having wings inclined and mounted on a steel pipe member having a wing and comprising a casing connected to the steel pipe pile by a connecting means so as to be capable of transmitting torque and detachably in an axial direction. Screwing and embedding in the ground; building a reinforcing bar or concrete column in the winged steel pipe member; and placing concrete or solidifying agent in the winged steel pipe member in which the reinforcing bar or concrete pile is built. Or a step of injecting, and a step of pulling out a casing during or after placing the concrete or the like. 4. The method for constructing a cast-in-place pile according to claim 3, wherein a steel pipe is attached to a portion of the pile head that contributes to horizontal resistance after the casing is pulled out. 5. The method for constructing a cast-in-place pile according to claim 3, wherein a lower end of the casing is held at a portion contributing to the horizontal resistance of the pile head when the casing is pulled out, and an upper part thereof is cut. 6. A steel pipe pile having wings inclined at or near the tip of a short pipe, an outer diameter of which is substantially equal to an outer diameter of the steel pipe pile, and torque can be transmitted to the steel pipe pile in an axial direction. A winged steel pipe member characterized by comprising a casing detachably connected to the casing. 7. The winged steel pipe member according to claim 6, wherein the short pipe and the casing are made of a square steel pipe. 8. The winged steel pipe member according to claim 6, wherein at least the casing is formed of a ribbed steel pipe. 9. A single-stage or plural-stage blade is formed by attaching one or a plurality of spiral blades or flat blades to a tip portion or a tip portion and an outer peripheral surface of a short tube. 9. A winged steel pipe member according to claim 7, 7 or 8. 10. A one-stage or plural-stage blade comprising one or more spiral blades or flat blades attached to an outer peripheral surface of a casing. Winged steel pipe member. 11. The winged steel pipe member according to claim 9, wherein the spiral wing or the flat wing is formed in a polygonal shape.