JP2022167394A - steel pipe pile - Google Patents

Abstract

To provide a steel pipe pile allowing efficient excavation and easy production to be carried out even in a gravel layer.SOLUTION: A steel pipe pile 1 is provided with: a pair of excavation blades 7, 7 symmetrically placed across an earth removal hole 5 formed in a center of an end plate 3; and a pair of notches 6, 6 symmetrically placed across a steel pipe pile body 2 around a peripheral edge part of the end plate 3, wherein excavation bits 9, 9 are supported on the edges of both of the notch 6, 6 in a circumferential direction so as to be directed downward in the same circumferential direction.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a steel pipe pile used in a so-called rotary penetration method.

Conventionally, there is known a steel pipe pile rotation penetration method in which a circular expanded disk is fixed to the lower end of a steel pipe pile by welding and the steel pipe pile is rotated to penetrate into the ground (see, for example, Patent Document 1).

This type of steel pipe pile is provided with cut-and-raised blades whose one end sides are raised respectively downward and upward along the peripheral edge of the diameter-expansion disk, and the diameter is expanded by cutting and raising the cut-and-raised blades. A notch is formed in the periphery of the disk.

In addition, this steel pipe pile has an excavation bit in the center of the lower surface of the expanding disk, and by pressing the steel pipe downward into the ground while rotating it, the upside-down sloping blades exert propulsive force. At the same time, the earth and sand excavated by the downward cut-and-raise blade and the excavation bit are moved upward from the notch and compacted, so that the steel pipe pile can be penetrated into the ground without discharging the earth.

JP 2010-281205 A

However, with the above-described conventional techniques, when gravel or other underground obstacles (hereinafter referred to as gravel or the like) exist in the ground, there is a problem that the gravel or the like gets entangled in the excavation opening, making excavation difficult. .

In addition, in the conventional technology, since the drilling bit is provided on one of the peripheral edges of the diameter-expanding disk, it is necessary to perform accurate centering, which causes the problem of requiring time for preparation.

Therefore, in view of such conventional problems, the present invention has been made for the purpose of providing a steel pipe pile that can be efficiently excavated even in a gravel layer or the like and that is easy to manufacture.

The feature of the invention described in claim 1 for solving the above-mentioned conventional problems is that the steel pipe pile body is provided with an end plate having a larger diameter than the steel pipe pile body that closes the lower end of the steel pipe pile body, and is installed in the ground by a rotary press-fitting method. WHEREIN: The said end plate is equipped with the earth-discharge mouth formed in the center, and a pair of notch parts arranged symmetrically on both sides of the said steel pipe pile main body in the peripheral part, and the circumference of both notch parts The drill bit is supported obliquely downward in the same circumferential direction on the directional edge.

A feature of the invention according to claim 2 is that, in addition to the configuration of claim 1, the end plate is provided with a pair of excavating blades supported in a symmetrical arrangement with the earth unloading port interposed therebetween.

The feature of the invention according to claim 3 resides in that, in addition to the configuration of claim 2, the end plate has a pair of earth-discharging tips arranged symmetrically with respect to the excavating blade with a gap therebetween.

A feature of the invention according to claim 4 is that, in addition to the configuration according to any one of claims 1 to 3, the base end of the drilling bit is welded to the circumferential edge of the notch. .

A feature of the invention according to claim 5 is that, in addition to the configuration of claim 4, the drilling bit is laterally supported by a reinforcing member fixed to the lower surface of the end plate.

ADVANTAGE OF THE INVENTION The steel pipe pile which concerns on this invention can excavate efficiently by few rotation speed, without impairing excavation efficiency also in the hard grounds, such as a gravel layer, by comprising the structure of Claim 1.

Moreover, in the present invention, by providing the configuration according to claim 2, the ground can be excavated efficiently.

In addition, in the present invention, by providing the configuration according to claim 3, excavated earth and sand can be pushed to the outside of the end plate, and the earth and sand can be efficiently moved upward through the notch.

Furthermore, by providing the configurations of claims 4 and 5, the excavation bit is firmly supported, and breakage of the excavation bit can be prevented even when dealing with hard ground such as a gravel layer.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows an example of the embodiment of the steel pipe pile which concerns on this invention. It is a partially enlarged front view showing the lower part of the steel pipe pile same as the above. It is a partial enlarged side view same as the above. It is a partial enlarged plan view same as the above. It is a partial enlarged bottom view same as the above. Fig. 3 is a partially enlarged perspective view showing the drilling bit portion of the same;

Next, embodiments of the steel pipe pile according to the present invention will be described based on the examples shown in FIGS. 1 to 6. FIG. In addition, the code|symbol 1 in a figure is a steel pipe pile.

As shown in FIG. 1, the steel pipe pile 1 includes a steel pipe pile body 2 made of a steel pipe and an end plate 3 closing the lower end of the steel pipe pile body 2. It has become.

The end plate 3 is formed in a disc shape having a larger diameter than the steel pipe pile body 2 having a certain thickness, and is fixed to the lower end of the steel pipe pile body 2 by welding or the like in a coaxial arrangement.

The end plate 3 has a soil discharge port 5 formed in the center and a pair of notches 6, 6 arranged symmetrically on the peripheral edge.

The end plate 3 also has a pair of excavating blades 7, 7 supported in a symmetrical arrangement across the unloading port 5, and a pair of unloading blades symmetrically arranged with an interval from the excavating blades 7, 7. It is provided with tips 8, 8 and drilling bits 9, 9 supported on the circumferential edges of both cutouts 6, 6 so as to face obliquely downward in the same circumferential direction.

The earth discharge port 5 is formed in a circular hole shape smaller than the inner diameter of the steel pipe pile main body 2 , penetrates the end plate 3 in the thickness direction, and communicates with the steel pipe pile main body 2 .

The cutouts 6, 6 are formed in a fan-shaped concave shape whose top, bottom, and outer peripheral sides are open along the peripheral edge of the end plate 3, and the drilling bit 9 is provided at the circumferential edge of the cutouts 6, 6 on the rear side in the rotation direction. , 9 are supported obliquely downward in the same circumferential direction.

The drilling bits 9, 9 are formed in an arc plate shape having a radius of curvature substantially the same as the radius of the end plate 3, and their base ends are fixed to the circumferential edges of the notches 6, 6 by welding 9a at a predetermined angle. , has a spiral shape, and the tip end protrudes obliquely downward spirally from the lower surface of the end plate 3 .

The drilling bits 9, 9 are formed separately from the end plate 3 in the shape of an arc plate having a certain thickness by casting or the like, and have high rigidity.

The excavation bits 9, 9 are integrally formed with a blade portion 9b at the tip portion in the circumferential direction. It has become.

The drilling bits 9 , 9 are supported at their sides by reinforcing members 10 fixed to the lower surface of the end plate 3 , and are firmly fixed to the end plate 3 via the reinforcing members 10 .

The reinforcing member 10 is formed in a block shape having an arc-shaped slope 10a, and is fixed to the lower surface of the end plate 3 along the inner edges of the notches 6, 6 by welding or the like. , 9 are fixed by welding or the like.

The reinforcing member 10 is fixed to the end plate 3 so that the inclined surface 10a faces the opposite side in the circumferential direction to the direction of the blade portions 9b of the digging bits 9,9.

The excavating blades 7, 7 have blades that are inclined from the tip edge 7a, and are fixed in a diametrically symmetrical arrangement with the edge 7a side facing outward.

The earth-discharging tips 8, 8 are formed in a flat plate shape having a slanted portion 8a on the lower surface thereof, and the slanted portion 8a is formed such that the outer side thereof is located at a lower distance from the lower surface of the end plate 3. As shown in FIG.

The earth-discharging tips 8, 8 are spaced apart from the excavating blades 7, 7 on the same side as the cutting edges 9b of the excavating bits 9, 9, that is, on the side opposite to the rotational direction of the steel pipe pile 1. are placed at

The form of the tip 8 for dumping soil is not limited to the embodiment described above, and the tip 8 for dumping soil may be formed in the shape of a square bar, for example.

The steel pipe pile 1 configured in this way forms a helical shape by rotating the steel pipe pile main body 2 and the end plate 3 in a predetermined direction, that is, with the cutting edges of the excavation bits 9, 9 facing forward in the rotation direction. The ground 4 is excavated by the excavation bits 9, 9 and the excavation blades 7, 7 with the propulsion force obtained by the excavation bits 9, 9, and is pressed downward into the ground 4 while forming the excavation hole 4a.

At that time, the earth and sand 11a excavated by the excavation blades 7, 7 and the excavation bits 9, 9 are introduced into the steel pipe pile main body 2 through the excavation opening 5, and the earth and sand around the excavation blades 7, 7 are introduced into the steel pipe pile main body 2. The earth and sand 11b of the part is pushed toward the excavation bits 9, 9 by the excavation tips 8, 8, guided to the upper surfaces of the spiral excavation bits 9, 9, and passed through the notches 6, 6 to the steel pipe pile main body. 2, i.e., into the excavation hole 4a forcibly discharging the steel pipe pile 1 into the ground 4 with no soil discharge, low vibration, and low noise.

In addition, even if there is an obstruction such as a gravel layer in the middle of the ground 4, the structure supports the strong excavation bits 9, 9 at the edges of the cutouts 6, 6. , and the excavation bits 9, 9 enable efficient excavation of a gravel layer or the like with a small number of revolutions.

Further, since the digging bit 9 is firmly supported by the reinforcing member 10, the cutting edge can be suitably penetrated into hard gravel or the like, and damage can be prevented.

Further, in the steel pipe pile 1 constructed in this way, the drilling bits 9, 9 are arranged symmetrically in the diametrical direction, so that centering is easy and the pile can be manufactured easily.

In the above-described embodiment, the earth-discharging tips 8, 8 are provided on the lower surface of the end plate 3, but the earth-discharging tips 8, 8 may be omitted if necessary.

Also, in the above-described embodiment, the case where the digging blades 7, 7 are provided on the lower surface of the end plate 3 has been described, but the digging blades 7, 7 may be omitted if necessary.

Moreover, although the above-mentioned Example demonstrated the case where the end plate 3 was directly fixed to the steel pipe pile main body 2, you may make an attachment an end plate.

REFERENCE SIGNS LIST 1 steel pipe pile 2 steel pipe pile body 3 end plate 4 ground 5 unloading port 6 notch 7 excavating blade 8 unloading tip 9 drilling bit 10 reinforcing member

TECHNICAL FIELD The present invention relates to a steel pipe pile used in a so-called rotary penetration method.

Conventionally, there is known a steel pipe pile rotation penetration method in which a circular expanded disk is fixed to the lower end of a steel pipe pile by welding and the steel pipe pile is rotated to penetrate into the ground (see, for example, Patent Document 1).

This type of steel pipe pile is provided with cut-and-raised blades whose one end sides are raised respectively downward and upward along the peripheral edge of the diameter-expansion disk, and the diameter is expanded by cutting and raising the cut-and-raised blades. A notch is formed in the periphery of the disk.

In addition, this steel pipe pile has an excavation bit in the center of the lower surface of the expanding disk, and by pressing the steel pipe downward into the ground while rotating it, the upside-down sloping blades exert propulsive force. At the same time, the earth and sand excavated by the downward cut-and-raise blade and the excavation bit are moved upward from the notch and compacted, so that the steel pipe pile can be penetrated into the ground without discharging the earth.

JP 2010-281205 A

However, with the above-described conventional techniques, when gravel or other underground obstacles (hereinafter referred to as gravel or the like) exist in the ground, there is a problem that the gravel or the like gets entangled in the excavation opening, making excavation difficult. .

In addition, in the conventional technology, since the drilling bit is provided on one of the peripheral edges of the diameter-expanding disk, it is necessary to perform accurate centering, which causes the problem of requiring time for preparation.

Therefore, in view of such conventional problems, the present invention has been made for the purpose of providing a steel pipe pile that can be efficiently excavated even in a gravel layer or the like and that is easy to manufacture.

The feature of the invention described in claim 1 for solving the above-mentioned conventional problems is that the steel pipe pile body is provided with an end plate having a larger diameter than the steel pipe pile body that closes the lower end of the steel pipe pile body, and is installed in the ground by a rotary press-fitting method. WHEREIN: The said end plate is equipped with the earth-discharge mouth formed in the center, and a pair of notch parts arranged symmetrically on both sides of the said steel pipe pile main body in the peripheral part, and the circumference of both notch parts A high-rigidity excavation bit, which is formed in a circular arc plate shape separately from the end plate, is supported diagonally downward in the same circumferential direction.

A feature of the invention according to claim 2 is that, in addition to the configuration of claim 1, the end plate is provided with a pair of excavating blades supported in a symmetrical arrangement with the earth unloading port interposed therebetween.

The feature of the invention according to claim 3 resides in that, in addition to the configuration of claim 2, the end plate has a pair of earth-discharging tips arranged symmetrically with respect to the excavating blade with a gap therebetween.

The feature of the invention according to claim 4 is that, in addition to the configuration according to any one of claims 1 to 3, the base end of the drilling bit is welded to the circumferential edge of the notch. be.

According to a fifth aspect of the invention, in addition to the configuration of the fourth aspect, the drilling bit is supported at its sides by reinforcing members fixed to the lower surface of the end plate.

ADVANTAGE OF THE INVENTION The steel pipe pile which concerns on this invention can excavate efficiently by few rotation speed, without impairing excavation efficiency also in the hard grounds, such as a gravel layer, by comprising the structure of Claim 1.

Moreover, in the present invention, by providing the configuration according to claim 2, the ground can be excavated efficiently.

In addition, in the present invention, by providing the configuration according to claim 3, excavated earth and sand can be pushed to the outside of the end plate, and the earth and sand can be efficiently moved upward through the notch.

Furthermore, by providing the configurations of claims 4 and 5, the excavation bit is firmly supported, and breakage of the excavation bit can be prevented even when dealing with hard ground such as a gravel layer.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows an example of the embodiment of the steel pipe pile which concerns on this invention. It is a partially enlarged front view showing the lower part of the steel pipe pile same as the above. It is a partial enlarged side view same as the above. It is a partial enlarged plan view same as the above. It is a partial enlarged bottom view same as the above. Fig. 3 is a partially enlarged perspective view showing the drilling bit portion of the same;

Next, embodiments of the steel pipe pile according to the present invention will be described based on the examples shown in FIGS. 1 to 6. FIG. In addition, the code|symbol 1 in a figure is a steel pipe pile.

As shown in FIG. 1, the steel pipe pile 1 includes a steel pipe pile body 2 made of a steel pipe and an end plate 3 closing the lower end of the steel pipe pile body 2. It has become.

The end plate 3 is formed in a disc shape having a larger diameter than the steel pipe pile body 2 having a certain thickness, and is fixed to the lower end of the steel pipe pile body 2 by welding or the like in a coaxial arrangement.

The end plate 3 has a soil discharge port 5 formed in the center and a pair of notches 6, 6 arranged symmetrically on the peripheral edge.

The end plate 3 also has a pair of excavating blades 7, 7 supported in a symmetrical arrangement across the unloading port 5, and a pair of unloading blades symmetrically arranged with an interval from the excavating blades 7, 7. It is provided with tips 8, 8 and drilling bits 9, 9 supported on the circumferential edges of both cutouts 6, 6 so as to face obliquely downward in the same circumferential direction.

The earth discharge port 5 is formed in a circular hole shape smaller than the inner diameter of the steel pipe pile main body 2 , penetrates the end plate 3 in the thickness direction, and communicates with the steel pipe pile main body 2 .

The cutouts 6, 6 are formed in a fan-shaped concave shape whose top, bottom, and outer peripheral sides are open along the peripheral edge of the end plate 3, and the drilling bit 9 is provided at the circumferential edge of the cutouts 6, 6 on the rear side in the rotation direction. , 9 are supported obliquely downward in the same circumferential direction.

The drilling bits 9, 9 are formed in an arc plate shape having a radius of curvature substantially the same as the radius of the end plate 3, and their base ends are fixed to the circumferential edges of the notches 6, 6 by welding 9a at a predetermined angle. , has a spiral shape, and the tip end protrudes obliquely downward spirally from the lower surface of the end plate 3 .

The drilling bits 9, 9 are formed separately from the end plate 3 in the shape of an arc plate having a certain thickness by casting or the like, and have high rigidity.

The excavation bits 9, 9 are integrally formed with a blade portion 9b at the tip portion in the circumferential direction. It has become.

The drilling bits 9 , 9 are supported at their sides by reinforcing members 10 fixed to the lower surface of the end plate 3 , and are firmly fixed to the end plate 3 via the reinforcing members 10 .

The reinforcing member 10 is formed in a block shape having an arc-shaped slope 10a, and is fixed to the lower surface of the end plate 3 along the inner edges of the notches 6, 6 by welding or the like. , 9 are fixed by welding or the like.

The reinforcing member 10 is fixed to the end plate 3 so that the inclined surface 10a faces the opposite side in the circumferential direction to the direction of the blade portions 9b of the digging bits 9,9.

The excavating blades 7, 7 have blades that are inclined from the tip edge 7a, and are fixed in a diametrically symmetrical arrangement with the edge 7a side facing outward.

The earth-discharging tips 8, 8 are formed in a flat plate shape having a slanted portion 8a on the lower surface thereof, and the slanted portion 8a is formed such that the outer side thereof is located at a lower distance from the lower surface of the end plate 3. As shown in FIG.

The earth-discharging tips 8, 8 are spaced apart from the excavating blades 7, 7 on the same side as the cutting edges 9b of the excavating bits 9, 9, that is, on the side opposite to the rotational direction of the steel pipe pile 1. are placed at

The form of the tip 8 for dumping soil is not limited to the embodiment described above, and the tip 8 for dumping soil may be formed in the shape of a square bar, for example.

The steel pipe pile 1 configured in this way forms a helical shape by rotating the steel pipe pile main body 2 and the end plate 3 in a predetermined direction, that is, with the cutting edges of the excavation bits 9, 9 facing forward in the rotation direction. The ground 4 is excavated by the excavation bits 9, 9 and the excavation blades 7, 7 with the propulsion force obtained by the excavation bits 9, 9, and is pressed downward into the ground 4 while forming the excavation hole 4a.

At that time, the earth and sand 11a excavated by the excavation blades 7, 7 and the excavation bits 9, 9 are introduced into the steel pipe pile main body 2 through the excavation opening 5, and the earth and sand around the excavation blades 7, 7 are introduced into the steel pipe pile main body 2. The earth and sand 11b of the part is pushed toward the excavation bits 9, 9 by the excavation tips 8, 8, guided to the upper surfaces of the spiral excavation bits 9, 9, and passed through the notches 6, 6 to the steel pipe pile main body. 2, i.e., into the excavation hole 4a forcibly discharging the steel pipe pile 1 into the ground 4 with no soil discharge, low vibration, and low noise.

In addition, even if there is an obstruction such as a gravel layer in the middle of the ground 4, the structure supports the strong excavation bits 9, 9 at the edges of the cutouts 6, 6. , and the excavation bits 9, 9 enable efficient excavation of a gravel layer or the like with a small number of revolutions.

Further, since the digging bit 9 is firmly supported by the reinforcing member 10, the cutting edge can be suitably penetrated into hard gravel or the like, and damage can be prevented.

Further, in the steel pipe pile 1 constructed in this way, the drilling bits 9, 9 are arranged symmetrically in the diametrical direction, so that centering is easy and the pile can be manufactured easily.

In the above-described embodiment, the earth-discharging tips 8, 8 are provided on the lower surface of the end plate 3, but the earth-discharging tips 8, 8 may be omitted if necessary.

Also, in the above-described embodiment, the case where the digging blades 7, 7 are provided on the lower surface of the end plate 3 has been described, but the digging blades 7, 7 may be omitted if necessary.

Moreover, although the above-mentioned Example demonstrated the case where the end plate 3 was directly fixed to the steel pipe pile main body 2, you may make an attachment an end plate.

REFERENCE SIGNS LIST 1 steel pipe pile 2 steel pipe pile body 3 end plate 4 ground 5 unloading port 6 notch 7 excavating blade 8 unloading tip 9 drilling bit 10 reinforcing member

Claims (5)

A steel pipe pile provided with an end plate having a diameter larger than that of the steel pipe pile body closing the lower end of the steel pipe pile body and installed in the ground by a rotary press-fitting method,
The end plate has a soil discharge port formed in the center and a pair of cutouts arranged symmetrically on the periphery with the steel pipe pile main body interposed therebetween. A steel pipe pile characterized in that bits are supported diagonally downward in the same circumferential direction. 2. The steel pipe pile according to claim 1, wherein said end plate includes a pair of excavating blades supported in a symmetrical arrangement with said unloading port interposed therebetween. 3. The steel pipe pile according to claim 2, wherein said end plate has a pair of earth-discharging tips arranged symmetrically with respect to said excavating edge in a circumferential direction. The steel pipe pile according to any one of claims 1 to 3, wherein the excavation bit has a base end welded to the circumferential edge of the notch. 5. The steel pipe pile according to claim 4, wherein the excavation bit is laterally supported by a reinforcing member fixed to the lower surface of the end plate.

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