JP2003119778A - Tip shoe for steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tip shoe for a steel pipe pile which can be used for quickly building a tip pile on the job site by assembling a tip pile by realizing an effective rotating excavating force by suppressing the resistance given to the tip edge surface even in a hard soil layer. SOLUTION: Straight two through slits 11 crossing at right angle at the center are provided; two excavating blades 2 as a pair are inserted to the through slits, coupled to the through slits, assembled to a cross-shaped shaft section, inserted to through slits and fixed on a bottom plate 1 by fitting the notched portion 10a provided at the outer peripheral edge 10 to the protruded edge portion 30a of the tip edge surface 30 of the steel pipe pile 3 and the blades are formed to converge at the tip intersecting portion 24. Also, at the time of conformity, the protruded edge portion of the steel pipe pile is extended from the bottom plate, and the outer peripheral portion of the blade body portion can be linked to the protruded edge portion if this is necessary. In addition, each of excavating blade can be inserted to each through slit from the opposite side of the bottom plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip shoe for a steel pipe pile mounted and fixed to the tip of the steel pipe pile.

[0002]

2. Description of the Related Art Conventionally, a tip shoe for a steel pipe pile used in a pile driving method in which a steel pipe pile is rotated to bite into a supporting ground, a blade fitting of various shapes is fixed to the tip of the steel pipe pile. There is. However, when the conventional tip shoe hits a hard soil layer with a high driving resistance, the resistance applied to the tip of the steel pipe pile is extremely increased, which causes the impossibility of driving and damage to the steel pipe pile. In addition, there are many things that disturb the ground around the pile during driving, and it was difficult to obtain the ground bearing capacity of the steel pipe pile due to frictional resistance after driving. Particularly, if the strength of the tip shoe of the steel pipe pile is low, the axis of the tip shoe may be inclined with respect to the axis of the steel pipe pile.

Further, the steel pipe piles for fixing the tip shoes have different specifications from the extension piles for intermediate use, and are generally manufactured separately as the piles for tip ends, so that they are matched to the specifications at the construction site. It was necessary to prepare in advance a number of piles for the tip and piles for the middle. However, in reality, one of them has an excess or deficiency or is damaged, and there is a complicated aspect such as replenishment or return.

[0004]

[Purpose] Therefore, the present invention has been made in view of the above problems, and even in a hard soil layer, the resistance received on the tip edge surface can be suppressed to a small extent to exhibit an effective rotary excavating force, and the tip shoe can be assembled. By providing a structure, a novel tip shoe for a steel pipe pile is provided which is capable of quickly constructing a pile for a tip on site and is excellent in transportability and handleability.

[0005]

The present invention which solves the above problems is configured as follows. That is, in claim 1, two linear through slits (1
1), the outer peripheral edge (10) of which is fitted and fixed to the tip edge surface (30) of the steel pipe pile (3), and the two through slits (1) in the bottom plate (1). 11) Inserted to a predetermined length, combined and fixed in a cross shape in the axial cross section, and composed of a pair of two excavating blades (2) formed so as to converge at the tip intersection (24). And

In the second aspect, the bottom plate (1) according to the first aspect.
When fitting the outer peripheral edge (10) of the steel pipe pile (3) with the tip edge surface (30) of the steel pipe pile (3), the protruding edge portion (30a) of the tip edge surface (30) of the steel pipe pile (3) is replaced with the bottom plate (1). It is characterized in that it is formed so as to fit with the notch (10a) provided on the outer peripheral edge (10).

In the third aspect, the bottom plate (1) according to the second aspect.
The protruding edge portion (30a) that fits with the cutout portion (10a) of the outer peripheral edge (10) of the blade is formed so as to extend beyond the bottom plate (1) when fitted, and the drilling is inserted into the bottom plate (1). Blade (2)
Of the blade body (20a, 22a) and the projecting edge (30
It is characterized in that it is configured to engage a).

According to a fourth aspect of the present invention, when inserting the pair of two excavating blades (2) into the orthogonal linear through slits (11) of the bottom plate (1) of the first aspect, the pair of two blades is inserted. Each of the digging blades (2) is inserted from the opposite side of the bottom plate (1) so as to sandwich the bottom plate (1) between the digging blades (2), and is combined.

[0009]

With the above structure, the present invention has the following effects. That is, according to the first aspect, the excavating blade that converges at the tip crossing portion is fixed to the bottom plate through the through slit. Further, according to the second aspect, since the excavating blade extends to the outer diameter of the steel pipe pile, the driving resistance of the steel pipe pile is small. Further, according to claim 3, since the excavating blade engages with the protruding edge portion of the tip edge surface of the steel pipe pile, the fixing strength of the excavating blade is improved, and the steel pipe pile falls into the impossibility of mounting, damage or damage. The occurrence of skidding is suppressed. In addition, according to the fourth aspect, since the bottom plate is sandwiched by the two excavating blades, the strength of the bottom plate is improved, and the ground supporting force after the steel pipe pile is placed is maintained for a long period of time.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, specific embodiments of a tip shoe for a steel pipe pile according to the present invention will be described in detail with reference to the drawings. 1 is an external perspective view of the tip shoe of the first embodiment example, FIG. 2 is an exploded perspective view showing an assembled state of the tip shoe of the first embodiment example, and FIG. 3 is a tip of the first embodiment example. It is a perspective view which shows the attachment state to the steel pipe pile of a shoe, and FIG. 4 is a partially cutaway perspective view which shows the attachment state to the steel pipe pile of the tip shoe of this Embodiment 1.
It should be noted that the drawings are drawn with the tip shoe facing downward in consideration of the actual usage form, and the directionality used in the following description is based on the drawings for convenience of explanation, but this does not limit the present invention. .

[0011]

[Embodiment 1] Tip shoe S for steel pipe pile of the present embodiment
(Hereinafter abbreviated as “tip shoe”) is attached and fixed to the tip of the steel pipe pile 3, and has a substantially disc-shaped bottom plate 1 and a flat plate-shaped 2 having a shape that converges at the tip intersection portion 24.
It is composed of one excavating blade 2 (2A, 2B).

The basic material and shape of the steel pipe pile 3 are the same as those of the conventional product, but the tip edge surface 30 (the lower end surface in the drawing) of the steel pipe pile 3 has a projecting edge slightly projected from the thickness of the bottom plate 1. The portion 30a is formed. This protruding edge portion 30a
Is formed by projecting two opposing portions in a range of a central angle of approximately 90 degrees from the axial center of the steel pipe pile 3 in a mountainous manner.

The bottom plate 1 is a steel disk having a diameter substantially the same as the outer diameter of the steel pipe pile 3, and the outer peripheral edge 10 thereof has the protruding edge portion 30a.
A notch portion 10a that fits with is formed. Further, the bottom plate 1 has a penetrating slit 11 which has two linear slits penetrating vertically and which are orthogonal to each other in the vicinity of the center so as to have a cross shape in a plan view.
Is formed. The through slit 11 has a length of about 2/3 to 3/4 of the diameter of the bottom plate 1, and the drilling blade 2
The notch portion 10a has a groove width of about A and 2B.
It is formed at a position along the notched end face 10b.

The two digging blades 2A and 2B are made of steel and formed into a substantially triangular plate shape, and are combined so that the tip end side thereof is aligned with the axial center line of the steel pipe pile 3 so that the axial cross section has a cross shape. Each of the excavating blades 2A and 2B is made up of constituent parts of blade bodies 20a and 21a and trunks 20b and 21b.

The blade body 20a of one of the excavating blades 2A has an isosceles triangular tip angle (90 degrees in this embodiment) on the tip side.
The length (maximum width of the excavating blade 2A) of the opposite side of the tip angle (the line segment connecting the bases of the isosceles sandwiching the tip angle) is made substantially equal to the diameter of the bottom plate 1, and the groove of the through slit 11 is formed. It has a thickness that matches the width. In addition, the digging blade 2A executive 2
0b is formed continuously from the opposite side, and has a rectangular shape having a width and a height that can fit and penetrate the through slit 11. Further, an orthogonal slit 20c having a predetermined length is formed from the center of the width at the upper end of the trunk portion 20b toward the blade body portion 20a so that it can be combined with the excavating blade 2B in an intersecting state.

The blade body portion 21a of the other excavating blade 2B has an isosceles triangular tip angle (90 degrees in this embodiment) on the tip side.
The length (maximum width of the excavating blade 2B) of the opposite side of the tip angle (the line segment connecting the bases of the isosceles sandwiching the tip angle) is made substantially equal to the length of the through slit 11, and the through slit is formed. It has a thickness adapted to the groove width of 11. Further, the orthogonal slit 21c having a predetermined length is formed from the tip of the blade body portion 21a toward the trunk portion 21b side so that it can be combined with the excavating blade 2A in an intersecting state. The trunk portion 21b of the excavating blade 2B is formed continuously with the blade body portion 21a, and is formed in a rectangular shape having a width substantially matching the inner diameter of the steel pipe pile 3 and a predetermined height.

[0017]

[Operation of Embodiment 1] With the above-mentioned structure, the bottom plates 1 and 2 are
As shown in FIG. 2, the combination of the two drilling blades 2A and 2B is performed by first inserting the trunk portion 20b of the drilling blade 2A into the through slit 11 from the lower surface side of the bottom plate 1 and placing the bottom side of the blade body portion 20a at the bottom plate 1. And the lower surface 12 of the bottom plate 1 is held by the excavating blade 2A. Then, the blade body portion 21b of the excavating blade 2B is inserted into the through slit 11 from the upper surface side of the bottom plate 1 to bring the stem portion 21b into contact with the bottom plate 1, and the orthogonal slit 21c of the blade body portion 21b and the blade of the excavating blade 2A. The orthogonal slit 20c of the body portion 20a is inserted so as to be opposed to each other and abutted, and the abutting portions thereof are welded and held. It should be noted that the two excavating blades 2A, 2B may be attached to the bottom plate 1 in any order.

[0018] And these, the tip edge surface 30 of the steel pipe pile 3
The steel pipe pile 3 for the tip is configured by adapting and welding the projecting edge portion 30a formed on the above and the notch portion 10a of the bottom plate 1 (FIGS. 3 and 4). In the tip shoe S thus configured, the two excavating blades 2A and 2B are combined from the upper and lower surfaces of the bottom plate 1, so that the tip side is reinforced and the strength is improved. Further, since both ends of the blade body portion 20a of the excavating blade 2A are welded in a state of being engaged with the projecting edge portion 30a, the strength of the excavating blade 2A is increased, and as a result, the strength of the tip shoe S is increased. .

On the other hand, since both ends of the trunk portion 21b of the excavating blade 2B are inscribed in the steel pipe pile 3, the strength of the steel pipe pile 3 is enhanced. Product accuracy can be improved by the combination of the digging blades 2A, 2B and the bottom plate 1 and the ease of positioning the tip shoe S and the tip edge surface 30 of the steel pipe pile 3. Also,
In the placement of the steel pipe pile 3 by the construction machine M with the axial rotation of the steel pipe pile 3, even the hard soil layer G has a sharp drilling blade 2
As a result, the resistance received on the tip edge surface 30 can be suppressed to a low level, the steel pipe pile 3 with the tip shoe S attached cannot fall into place, and there is no damage or skidding, which is excellent in workability, and the steel pipe pile 3 can be driven. Since the bottom plate 1 is flat after installation, the ground supporting force is maintained for a long time (FIG. 5).

[0020]

[Embodiment 2] This Embodiment 2 shows a modified example of a combination of excavating blades to be combined. Instead of the excavating blade 2B used in Embodiment 1, the orthogonal slit 22c in the excavating blade 2A is used. The digging blade 2C formed on the side of the blade body 22a and the digging blade 2A are cross-inserted and combined. After that, the trunk portions 20b and 22b are inserted into the through slit 11 of the bottom plate 1 from the lower surface side in a state of being orthogonal to each other and fixed to each other. In the configuration of the present second embodiment example, the blade body portions 20 of both the drilling blade 2A and the drilling blade 2C are provided.
Both ends of a and 22a have protruding edges 30 when rotating.
Since it comes into contact with a, it serves as a four-point support and can be reinforced during rotation (FIG. 6).

[0021]

[Embodiment 3] This Embodiment 3 shows a modified example of how to combine the excavating blades to be combined. Instead of the excavating blade 2A used in Embodiment 1, the orthogonal slit 23c in the excavating blade 2B is used. The digging blade 2D formed on the side of the trunk portion 23b and the digging blade 2B are cross-inserted and combined. After that, the trunks 21b and 23b are inserted into the through slit 11 of the bottom plate 1 from the upper surface side in a state of being orthogonal to each other, and the trunks 21b and 23b are fixed to each other. In the configuration of the third embodiment, the trunks 21b, 2b of both the digging blade 2B and the digging blade 2D are provided.
Since both ends of 3b are inscribed in the steel pipe pile 3 at four locations, reinforcement during rotation during driving is achieved (Fig. 7).

[0022]

[Effect] The tip shoe for a steel pipe pile according to the present invention having the above-described structure has the following effects. That is, even in a hard soil layer, it is possible to suppress the resistance received on the tip edge surface to a small amount, so that the steel pipe pile falls into a place where it cannot be placed, and it is less likely to cause damage or skid, which is excellent in workability,
Further, since the bottom plate is a flat surface after placing the steel pipe pile, it becomes possible to maintain a large ground supporting force for a long period of time.

Furthermore, since the tip shoe is made up of a combination of three plate materials, it has excellent transportability and handleability, and the tip shoe can be attached to the prepared steel pipe pile for intermediate connection on site. It also has a remarkable effect that can be quickly dealt with as a tip pile.

[Brief description of drawings]

FIG. 1 is an external perspective view of a tip shoe according to a first embodiment.

FIG. 2 is an exploded perspective view showing an assembled state of the tip shoe of the first embodiment.

FIG. 3 is a perspective view showing how the tip shoe of the first embodiment is attached to a steel pipe pile.

FIG. 4 is a partially cutaway perspective view showing a state where the tip shoe of the first embodiment is attached to a steel pipe pile.

FIG. 5 is a perspective view showing a driving operation using a steel pipe pile using the tip shoe of the first embodiment.

FIG. 6 is an exploded perspective view showing an assembled state of the tip shoe of the second embodiment.

FIG. 7 is an exploded perspective view showing an assembled state of the tip shoe of the third embodiment.

[Explanation of symbols]

S tip shoe 1 bottom plate 10 outer periphery 10a Notch 10b Notched end face 11 through slit 12 Lower surface 13 Upper surface 2 drilling blade 2A drilling blade 20a blade body 20b executive 20c Orthogonal slit 2B drilling blade 21a Blade part 21b Executive 21c Orthogonal slit 2C drilling blade (embodiment example 2) 22a Blade part 22b Executive 22c Orthogonal slit 2D drilling blade (Embodiment 3) 23a Blade part 23b Executive 23c Orthogonal slit 24 Tip intersection 3 steel pipe pile 30 Tip edge surface 30a protruding edge G soil layer M construction machine

Claims (4)

[Claims] 1. A bottom plate having two linear through slits (11) orthogonal to each other in the center, and an outer peripheral edge (10) of which is fitted and fixed to a tip edge surface (30) of a steel pipe pile (3). (1) and the two through slits (11) in the bottom plate (1)
It is characterized in that it comprises a pair of two excavating blades (2) formed so as to be converged at the tip crossing portion (24) while being inserted into a predetermined length to be combined and fixed in a cross shape in axial cross section. Tip shoe for steel pipe piles. 2. When fitting the outer peripheral edge (10) of the bottom plate (1) and the tip edge surface (30) of the steel pipe pile (3), the protruding edge portion of the tip edge surface (30) of the steel pipe pile (3). (30a)
Is provided on the outer peripheral edge (10) of the bottom plate (1).
0a) is formed so as to be compatible with 0a), and the tip shoe for a steel pipe pile according to claim 1. 3. A projecting edge portion (30a) which fits with a cutout portion (10a) of an outer peripheral edge (10) of the bottom plate (1) is formed so as to extend beyond the bottom plate (1) when fitted. Bottom plate (1)
Body part (20a, 22a) of the drilling blade (2) inserted in the
The tip shoe for a steel pipe pile according to claim 2, characterized in that the outer peripheral portion and the protruding edge portion (30a) are configured to engage with each other. 4. When inserting a pair of two digging blades (2) into each of the orthogonal linear through slits (11) of the bottom plate (1), a pair of digging blades (2) forms a bottom plate (2). The tip shoe for a steel pipe pile according to claim 1, wherein each of the excavating blades (2) is inserted from the opposite side of the bottom plate (1) so as to sandwich 1).