JP2004176438A - Steel pipe pile and reinforcing member for blade for steel pipe pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steel pipe pile and a reinforcing member for a blade for the steel pipe pile capable of increasing ground supporting force without increasing outside diameter of the blade. <P>SOLUTION: This steel pipe pile 11 is provided with a deformation suppressing structure for suppressing deformation (for example, upward warping back) of the blades 15a, 15b accompanying screwing-in of the steel pipe pile 11 into the ground. The whole peripheries of the blades 15a, 15b are together covered to fix the reinforcing member 21 to outer peripheral fringes of the blades 15a, 15b. To explain concretely, the cylindrical reinforcing member 21 whose both ends are opened is inserted into the steel pipe pile 11 on which the blades 15a, 15b are fixed, and the outer peripheral fringes of the blades 15a, 15b and an inner peripheral face of the reinforcing member 21 are fixed by welding in this condition to prevent deformation of the blades 15a, 15b accompanying screwing-in of the steel pipe pile 11 into the ground. Consequently, ground supporting force by the blades 15a, 15b is increased without increasing outside diameter of the blades 15a, 15b. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a screw-in type steel pipe pile and a reinforcing member for a blade for a steel pipe pile used as a foundation of a building, for example.
[0002]
[Prior art]
Conventionally, the following steel pipe piles are known. That is, as shown in FIG. 13A, the steel pipe pile 51 includes a steel pipe 52 and a pair of blades 53a and 53b fixed to the outer peripheral surface near the tip of the steel pipe 52 so as to be inclined at a predetermined angle. I have. When a rotational force and a pressing force in the screwing direction are applied to the steel pipe pile 51 by a construction device (not shown) installed on the ground, the steel pipe pile 51 is screwed into the ground by the screw action of the blades 53a and 53b (for example, And Patent Document 1.).
[0003]
[Patent Document 1]
JP-A-10-292370
[Problems to be solved by the invention]
However, the conventional steel pipe pile has the following problems. That is, as shown in FIG. 13B, the blades 53a and 53b receive a reaction force (ground reaction force) from the ground with the screwing of the steel pipe pile 51 into the ground, and the blades 53a and 53b Bending moment is applied. As a result, the blades 53a and 53b warp upward, and the ground supporting force of the steel pipe pile 51 is reduced. For this reason, the blades 53a and 53b have been designed in consideration of a decrease in the ground support force due to the warpage (deformation) of the blades 53a and 53b.
[0005]
That is, as shown in FIG. 14, the ground support force of the steel pipe pile 51 is calculated by setting the effective diameter de of the blades 53a and 53b to １ ／ of the outer diameter d of the blades 53a and 53b. When increasing the ground support force, it is common to increase the outer diameter of the blades 53a and 53b. Therefore, there is a problem that the outer diameter of the blades 53a and 53b increases as the ground support force is increased. there were.
[0006]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a steel pipe pile and a reinforcing member for a steel pipe pile blade capable of increasing the ground support force without increasing the outer diameter of the blade. Is to provide.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is a steel pipe pile that is screwed into the ground using one or more blades attached to a lower portion of a steel pipe, wherein the one or more blades are screwed into the ground. The gist is to provide a deformation suppressing structure for suppressing deformation of the blade due to a ground reaction force.
[0008]
According to a second aspect of the present invention, in the steel pipe pile according to the first aspect, the deformation suppressing structure is fixed to an outer peripheral edge of the blade so as to collectively cover an entire circumference of one or more blades. The gist is to be a member.
[0009]
According to a third aspect of the present invention, in the steel pipe pile according to the first aspect, a plurality of blades are respectively provided on a lower outer peripheral surface of the steel pipe at the same angle with respect to a plane orthogonal to a central axis of the steel pipe and to the ground. The invention is characterized in that the deformation suppressing structure is provided with one or more reinforcing members for interconnecting a part or all of the outer peripheral edge of each blade with each other so as to be inclined downward in the rotation direction of the steel pipe at the time of screwing. And
[0010]
The invention according to claim 4 is a reinforcing member for a steel pipe pile blade that is attached to one or more blades provided at a lower portion of the steel pipe pile and suppresses deformation of the blade due to screwing into the ground, The gist of the present invention is that the blade is formed so as to collectively cover the entire circumference of one or more blades.
[0011]
The invention according to claim 5 is a reinforcing member for a steel pipe pile blade, which is attached to a plurality of blades provided at a lower portion of the steel pipe pile and suppresses deformation caused by screwing the blade into the ground. The gist of the present invention is that a part or the whole of the outer peripheral edge of each of them is formed so as to be connected to each other.
[0012]
(Action)
According to the first aspect of the invention, deformation of one or more blades due to the ground reaction force is suppressed. Therefore, unlike the case where the deformation suppressing structure is not provided, the ground support force of the steel pipe pile increases without increasing the outer diameter of the blade.
[0013]
According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the reinforcing member is fixed to the outer peripheral edge of the blade so as to collectively cover the entire circumference of one or more blades. Is done. For this reason, one or more blades are less likely to deform.
[0014]
According to the third aspect of the invention, some or all of the outer peripheral edges of the plurality of blades are interconnected by one or more reinforcing members. For this reason, the deformation of each blade caused by the ground reaction force when the steel pipe pile is screwed is suppressed. Therefore, unlike the case where no reinforcing member is provided, the ground support force increases without increasing the outer diameter of the blade.
[0015]
According to the invention as set forth in claim 4, the reinforcing member of the steel pipe pile blade is arranged so as to collectively cover the entire circumference of one or more blades, and in this state, the reinforcing member is attached to the outer peripheral edge of the blade. By fixing, the deformation of the blade due to the screwing of the steel pipe pile into the ground is suppressed. Therefore, the ground support force increases without increasing the outer diameter of the blade.
[0016]
According to the invention described in claim 5, by connecting the outer peripheral edges of the plurality of blades provided at the lower part of the steel pipe pile to each other with the reinforcing member of the steel pipe pile blade, the steel pipe pile is screwed into the ground. The deformation of each blade is suppressed. Therefore, the ground support force increases without increasing the outer diameter of each blade.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, an embodiment in which the present invention is embodied in a screw-in type steel pipe pile used as a foundation of a building, for example, will be described with reference to FIGS.
[0018]
(Overall configuration)
As shown in FIGS. 1 and 2, a steel pipe pile 11 is a tubular steel pipe 12 having both ends opened, a plate-shaped closing member 13 for closing the lower end opening of the steel pipe 12, and a lower surface of the closing member 13, ie, a steel pipe. 12 is provided with a tip bit 14 provided on the tip face, and a pair of blades 15a and 15b also provided on the lower outer peripheral face of the steel pipe 12. Further, the steel pipe pile 11 includes a reinforcing member 21 fixed to the outer peripheral edges of the blades 15a, 15b so as to cover the entire circumference of the blades 15a, 15b.
[0019]
(Occlusion member)
The closing member 13 is fixed to the lower end opening of the steel pipe 12 by welding. When the steel pipe pile 11 is screwed into the ground, the closing member 13 pushes out the earth and sand or gravel on the lower end side of the steel pipe pile 11 to the outer peripheral side of the steel pipe pile 11, and after the screwing is completed, a reaction force from the ground (hereinafter, referred to as “the ground”). In response to "ground reaction force."
[0020]
(Tip bit)
The tip bit 14 (digging blade) is formed in a pentagonal shape by a plate material. The height of the tip bit 14 from the lower surface of the closing member 13 becomes higher toward the center of the lower surface of the closing member 13, and the height of the protrusion from the lower surface of the closing member 13 becomes lower toward the outer peripheral edge. It is fixed to be orthogonal to the lower surface of the closing member 13. When the steel pipe pile 11 is screwed into the ground, the tip bit 14 functions as an excavation guide that excavates and softens soil and gravel on the lower end side (tip side) of the steel pipe pile 11 and guides the screwing of the steel pipe pile 11 into the ground. .
[0021]
(Feather)
The blades 15a and 15b are formed in a fan shape by dividing a donut-shaped plate material having an outer diameter larger than the outer diameter of the steel pipe 12 and having an inner diameter substantially equal to the outer diameter of the steel pipe 12 at the center. The blades 15a and 15b are fixed to the outer peripheral surface of the distal end of the steel pipe 12 at the respective inner peripheral edges by welding. The blades 15a and 15b are at the same angle with respect to a plane S (see FIG. 1) orthogonal to the central axis of the steel pipe 12 and in the direction of rotation of the steel pipe 12 when screwed into the ground (arrows shown in FIGS. 1 and 2). (A direction) is attached to the outer peripheral surface of the steel pipe 12 so as to be inclined downward. The start ends 15ao, 15bo of the blades 15a, 15b are also located on the lower end side (downward in FIG. 1) of the steel pipe 12 with respect to the end parts 15ae, 15be.
[0022]
When the steel pipe pile 11 is screwed into the ground, the blades 15a and 15b bite into the unexcavated ground (soil and sand and gravel) on the outer peripheral side of the steel pipe pile 11 due to the rotation of the steel pipe pile 11, and the soil and sand are placed on the upper parts of the blades 15a and 15b. The strength of the gravel acts as a reaction force. Therefore, a driving force in the screwing direction acts on the steel pipe pile 11. After the screwing of the steel pipe pile 11 is completed, the steel pipe pile 11 receives the ground reaction force together with the closing member 13 to exhibit the ground supporting force.
[0023]
(Reinforcing member)
The reinforcing member 21 is formed so as to collectively cover the entire circumference of the blades 15a and 15b. In other words, the reinforcing member 21 is formed so as to connect all the outer peripheral edges of the blades 15a and 15b to each other. The reinforcing member 21 is fixed to the outer peripheral edges of the blades 15a and 15b by welding so as to collectively cover the entire circumference of the blades 15a and 15b.
[0024]
More specifically, the reinforcing member 21 is formed in a cylindrical shape with both ends opened, and the inner diameter of the reinforcing member 21 is substantially the same as the outer diameter (tip enlarged diameter) d of the blades 15a and 15b. . Then, with the reinforcing member 21 inserted into the steel pipe pile 11 to which the blades 15a and 15b are fixed, the outer peripheral edges of the blades 15a and 15b and the inner peripheral surface of the reinforcing member 21 are fixed by welding. The reinforcing members 21 are arranged so that the upper edges (end portions 15ae, 15be) and the lower edges (starting portions 15ao, 15bo) of the blades 15a, 15b do not protrude from the upper and lower edges of the reinforcing member 21, respectively.
[0025]
In the present embodiment, the reinforcing member 21 forms a deformation suppressing structure that suppresses deformation (for example, upward curling) of the blades 15a and 15b due to the screwing of the steel pipe pile 11 into the ground.
[0026]
(Operation of the embodiment)
Next, an operation at the time of construction of the steel pipe pile configured as described above will be described.
When the steel pipe pile 11 is buried in the ground, the steel pipe pile 11 is erected on the ground where the steel pipe pile 11 is to be buried by a construction device (not shown) installed on the ground, and in this state, the steel pipe pile 11 is turned in the rotational direction and the screwing direction. Of pressing force. Then, the steel pipe pile 11 is screwed into the ground (underground) by the screw action of the blades 15a and 15b while excavating and softening the ground with the tip bit 14. That is, the blades 15a and 15b bite into the ground on the outer peripheral side of the steel pipe pile 11, and the steel pipe pile 11 is rotationally propelled into the ground by using the resistance force of the earth and sand or gravel acting on the upper surfaces of the blades 15a and 15b as a reaction force. The earth and sand and gravel on the lower end side of the steel pipe pile 11 are pushed out to the outer peripheral side of the steel pipe pile 11 as the steel pipe pile 11 is screwed.
[0027]
As the steel pipe pile 11 is screwed into the ground, the blades 15a and 15b receive a reaction force (ground reaction force) from the ground below their respective lower surfaces, and a bending moment acts upward. However, since the outer peripheral edges of the blades 15a, 15b are fixed to the inner peripheral edge of the reinforcing member 21, the blades 15a, 15b (particularly, the starting ends 15ao, 15a, 15b of the blades 15a, 15b) are screwed into the ground of the steel pipe pile 11. 15bo; biting portion) does not warp upward. Therefore, unlike the case where the reinforcing member 21 is not provided, the ground supporting force by the blades 15a and 15b is secured.
[0028]
When the lower end (tip) of the steel pipe pile 11 reaches the predetermined support layer G (see FIG. 4), the screwing of the steel pipe pile 11 into the ground is completed. Since the ground supporting force by the blades 15a and 15b is increased as compared with the case where the blades 15a and 15b are deformed without providing the reinforcing member 21, the screwing depth D of the steel pipe pile 11 can be reduced (FIG. 4).
[0029]
(Effects of the embodiment)
Therefore, according to the present embodiment, the following effects can be obtained.
(1) The steel pipe pile 11 is provided with a deformation suppressing structure for suppressing the deformation (upward curling) of the blades 15a and 15b due to the screwing of the steel pipe pile 11 into the ground. That is, the reinforcing member 21 is fixed to the outer peripheral edges of the blades 15a and 15b so as to cover the entire circumference of the blades 15a and 15b at once. In other words, the entire outer peripheral edges of the blades 15a and 15b are connected to each other by the reinforcing member 21. For this reason, deformation of the blades 15a and 15b due to the screwing of the steel pipe pile 11 into the ground is suppressed. Therefore, unlike the case where the reinforcing member 21 is not provided, the ground supporting force by the blades 15a, 15b and, consequently, the ground supporting force of the entire steel pipe pile 11 are increased without increasing the outer diameter d of the blades 15a, 15b. be able to.
[0030]
(2) The ground support force of the blades 15a and 15b, and thus the ground support force of the steel pipe pile 11, are increased, so that the screw-in depth D of the steel pipe pile 11 can be reduced. Further, the steel pipe 12 can be shortened by the amount by which the screwing depth D of the steel pipe pile 11 is reduced.
[0031]
(3) The cylindrical reinforcing member 21 having both ends opened is inserted into the steel pipe pile 11 to which the blades 15a and 15b are fixed, and in this state, the outer peripheral edges of the blades 15a and 15b and the inner peripheral surface of the reinforcing member 21 are welded. To fix it. That is, since the reinforcing member 21 is simply fixed to the blades 15a and 15b, it can be easily retrofitted to an existing steel pipe pile in which a plate-like or spiral blade is provided at the tip of the steel pipe 12. Further, the configuration does not become complicated.
[0032]
(4) The reinforcing member 21 is fixed to the outer peripheral edges of the blades 15a and 15b so as to cover the entire circumferences of the blades 15a and 15b. For this reason, the behavior of the steel pipe pile 11 when screwed into the ground is stabilized. Further, the positioning accuracy of the steel pipe pile 11 when screwed into the ground is improved. That is, misalignment of the steel pipe pile 11 during screwing can be suppressed.
[0033]
(5) The deformation of the blades 15a and 15b when the steel pipe pile 11 is screwed is suppressed by the reinforcing member 21. Therefore, the thickness of the blades 15a and 15b can be reduced as compared with the case where the reinforcing member 21 is not provided.
[0034]
(6) Even if the outer diameter d of the blades 15a, 15b is increased to increase the ground support force, the deformation of the blades 15a, 15b is suppressed by the reinforcing member 21, so that the thickness of the blades 15a, 15b is reduced. The increase can be suppressed as much as possible.
[0035]
(7) The reinforcing member 21 is formed in a cylindrical shape with both ends opened. Therefore, manufacturing is simple. Further, the configuration is simple, and the mounting to the blades 15a and 15b is also simple. Furthermore, it can respond to mass production.
[0036]
(2nd Embodiment)
Next, a second embodiment of the present invention will be described. This embodiment is different from the first embodiment in the configuration of the reinforcing member 21. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.
[0037]
As shown in FIG. 5, the intermediate portion of the peripheral wall of the reinforcing member 21 (for example, between the starting end 15 ao of the blades 15 a and 15 b and the terminal end 15 be of the blade 15 b, and the starting end 15 bo of the blade 15 b and the terminal end 15 ae of the blade 15 a). Are formed with a plurality of outlets 22. In the process of screwing the steel pipe pile 11, earth and sand and gravel on the lower end side of the steel pipe pile 11 excavated and softened by the tip bit 14 are pushed out to the outer peripheral side of the steel pipe pile 11 with the screwing of the steel pipe pile 11, and the discharge port 22 is discharged. The steel is then discharged to the outer peripheral side of the steel pipe pile 11. Therefore, according to the present embodiment, in addition to the effects described in (1) to (7) of the first embodiment, the earth and sand and gravel on the lower end side of the steel pipe pile 11 may stay in the reinforcing member 21. Thus, the steel pipe pile 11 can be screwed into the ground more smoothly.
[0038]
(Third embodiment)
Next, a third embodiment of the present invention will be described.
As shown in FIG. 6, a plurality of blades 23a and 23b are further provided on the outer peripheral surface of the reinforcing member 21. The blades 23a and 23b are formed in a fan shape by being divided into two around a donut-shaped plate material having an outer diameter larger than the outer diameter of the reinforcing member 21 and an inner diameter substantially equal to the outer diameter of the reinforcing member 21. ing. The blades 23a and 23b are fixed to the outer peripheral surface of the reinforcing member 21 by welding at the respective inner peripheral edges. The blades 23a and 23b are attached at the same angle with respect to a plane perpendicular to the central axis of the steel pipe 12 and inclined downward in the rotation direction of the steel pipe pile 11 when screwed into the ground. The blades 23a and 23b are on the same virtual planes F1 and F2 together with the blades 15a and 15b.
[0039]
Therefore, according to this embodiment, in addition to the effects described in (1) to (7) of the first embodiment, the ground support force of the steel pipe pile 11 is increased by the area of the lower surfaces of the blades 23a and 23b. Can be done. Also, unlike the case where the blades 15a, 15b and the blades 23a, 23b are integrally formed, the bending moment acting on the blades 23a, 23b with the screwing of the steel pipe pile 11 is reduced. For this reason, the upward warpage of the blades 23a and 23b is also small, and the ground support force is effectively exerted. In FIG. 5, the blade 15a is indicated by a two-dot chain line (virtual line).
[0040]
(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described.
As shown in FIG. 7, the reinforcing member 21 is formed so as to cover half of the upper edges (end portions 15ae, 15be) of the blades 15a, 15b. The outer peripheral edge of a half on the upper edge side of the blades 15a and 15b and the inner peripheral surface of the reinforcing member 21 are fixed by welding. For this reason, according to the present embodiment, in addition to the effects described in (2) to (7) of the first embodiment, the deformation (warping) of at least a half of the upper ends of the blades 15a and 15b is suppressed. Can be.
[0041]
(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described.
As shown in FIG. 8, the reinforcing member 21 is formed so as to cover half of the lower edges (starting ends 15ao, 15bo) of the blades 15a, 15b. The outer peripheral edge of the lower end half of the blades 15a and 15b and the inner peripheral surface of the reinforcing member 21 are fixed by welding. For this reason, according to the present embodiment, in addition to the effects described in (2) to (7) of the first embodiment, it is possible to suppress deformation (warping) in at least the lower end halves of the blades 15a and 15b. Can be.
[0042]
(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described.
As shown in FIG. 9, the reinforcing member 21 is formed so as to cover an intermediate portion (between the start ends 15ao, 15bo and the end portions 15ae, 15be) of the blades 15a, 15b. The outer peripheral edge of the intermediate portion between the blades 15a and 15b and the inner peripheral surface of the reinforcing member 21 are fixed by welding. Therefore, according to the present embodiment, in addition to the effects described in (2) to (7) of the first embodiment, compared with the case where the reinforcing member 21 is not provided, the steel pipe pile 11 is screwed in. The accompanying deformation (warpage) of the blades 15a, 15b can be suppressed.
[0043]
(Seventh embodiment)
Next, a seventh embodiment of the present invention will be described.
As shown in FIGS. 10A and 10B, the reinforcing member 21 is formed so that a part of the outer peripheral edges of the blades 15a and 15b can be connected to each other. That is, the reinforcing member 21 includes a first reinforcing member 21a that connects the lower edge of the blade 15a and the upper edge of the blade 15b, and a second reinforcing member 21b that connects the upper edge of the blade 15a and the lower edge of the blade 15b. It has.
[0044]
A first reinforcing member 21a is fixed by welding between the outer peripheral edge on the lower edge (starting end 15ao) side of the blade 15a and the outer peripheral edge on the upper edge (end portion 15be) of the blade 15b. A second reinforcing member 21b is fixed by welding between an outer peripheral edge on the upper edge (end portion 15ae) side of the blade 15a and an outer peripheral edge on the lower edge (start end portion 15bo) side of the blade 15b. For this reason, according to the present embodiment, in addition to the effects described in (1) to (7) of the first embodiment, the reinforcing member 21 is formed so as to cover the entire circumference of the blades 15a and 15b. The material cost of the reinforcing member 21 can be reduced as compared with the case of the above.
[0045]
(Another example)
The above-described embodiment may be modified and implemented as follows.
In the first to seventh embodiments, only one set of the blades 15a and 15b is provided, but a plurality of sets may be provided. For example, two sets of blades 15a and 15b are arranged and fixed on the outer peripheral surface of the steel pipe 12 at predetermined intervals in a direction along the central axis of the steel pipe 12. Then, the reinforcing member 21 is fixed for each set. Alternatively, the blades 15a, 15b of each set are collectively covered with the reinforcing member 21, and the outer peripheral edges of the blades 15a, 15b of each pair and the inner peripheral surface of the reinforcing member 21 are fixed by welding. In this way, in the steel pipe pile in which the blades 15a and 15b are provided in multiple stages, the same effects as the effects described in (1) to (7) of the first embodiment can be obtained.
[0046]
In the first to seventh embodiments, the plurality of blades 15a and 15b are fixed to the outer peripheral surface of the steel pipe 12, but one continuous spiral blade or a plurality of discontinuous spiral blades is fixed. May be wound around the outer peripheral surface of the steel pipe pile 11 and fixed. Then, the entire periphery of the spiral blade is collectively covered by the reinforcing member 21, and the outer peripheral edge of the spiral blade and the inner peripheral surface of the reinforcing member 21 are fixed by welding. In this way, in the steel pipe pile having the spiral blades, the same effects as the effects (1) to (7) of the first embodiment can be obtained.
[0047]
In the first to seventh embodiments, the two blades 15a and 15b are fixed to the outer peripheral surface of the steel pipe 12, but three, four or more blades are fixed to the outer peripheral surface of the steel pipe 12. You may do so. Then, the outer periphery of each blade is collectively covered with the reinforcing member 21, and the outer peripheral edge of each blade and the inner peripheral surface of the reinforcing member 21 are fixed by welding. In this way, in a steel pipe pile having three abnormal blades, the same effects as the effects (1) to (7) of the first embodiment can be obtained.
[0048]
In the seventh embodiment, the reinforcing member 21 is constituted by the two members of the first reinforcing member 21a and the second reinforcing member 21b. However, the reinforcing member 21 may be constituted by three, four or more members. Then, for example, each member constituting the reinforcing member 21 is fixed to the outer peripheral edges of the blades 15a and 15b at predetermined intervals. Even in this case, the effects described in (1) to (7) of the first embodiment and the effects similar to those of the seventh embodiment can be obtained.
[0049]
As shown in FIG. 11A, a tapered surface 21ta may be formed on the inner peripheral side of the lower end edge of the reinforcing member 21. Further, as shown in FIG. 11B, a tapered surface 21tb may be formed on the outer peripheral side of the lower edge of the reinforcing member 21. Further, as shown in FIG. 11C, tapered surfaces 21tc may be formed on the inner peripheral side and the outer peripheral side of the lower end edge of the reinforcing member 21, respectively. In this way, when the steel pipe pile 11 is screwed into the ground, the resistance of the ground acting on the reinforcing member 21 is reduced, and the screwing can be performed more smoothly.
[0050]
In the first to sixth embodiments, the reinforcing member 21 is a single member. However, the reinforcing member 21 may be divided into a plurality in the circumferential direction of the center axis of the reinforcing member 21. For example, as shown in FIGS. 12A and 12B, the reinforcing member 21 is divided into two parts and four parts. In this way, the transportation of the reinforcing member 21 is simplified. Further, handling of the reinforcing member 21 is also simplified.
[0051]
(Note)
Next, technical ideas that can be grasped from the embodiment and other examples will be additionally described below.
(A) The steel pipe pile according to claim 3, wherein the reinforcing member includes a plurality of connecting members for connecting at least an outer peripheral edge on the starting end side and an outer peripheral edge on the terminal end side of adjacent blades.
[0052]
(B) The steel pipe pile according to claim 3, wherein the reinforcing member is fixed to an outer peripheral edge of each blade so as to surround the entire circumference of each blade.
(C) The steel pipe pile according to the above (A), wherein the reinforcing member connects the outer peripheral edge on the starting end side, the outer peripheral edge near the middle part, or the outer peripheral edge on the terminal end side of each blade.
[0053]
(D) The steel pipe pile according to claim 2 or 3, wherein a discharge port for earth and sand or gravel is formed in a peripheral wall of the reinforcing member. According to this configuration, since earth and sand and gravel are discharged through the discharge port, the screwing speed of the steel pipe pile is secured, and the screwing of the steel pipe pile can be performed smoothly.
[0054]
(E) The steel pipe pile according to claim 2, wherein one or more blades are further provided on an outer peripheral surface of the reinforcing member. According to this configuration, the ground support force of the steel pipe pile can be increased. Further, as compared with a case where the blades are formed so as to have the same outer diameter without the interposition of the reinforcing member and the blades are fixed to the outer peripheral surface of the steel pipe, the blade is fixed to the reinforcing member (inner peripheral edge). Since the distance to the outer peripheral edge is short, the bending moment due to the ground reaction force is reduced. As a result, deformation of the blade fixed to the outer periphery of the reinforcing member is suppressed.
[0055]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the deformation | transformation of the blade | wing accompanying the screwing of the steel pipe pile into the ground is suppressed, and the ground support force of a steel pipe pile can be increased, without enlarging the outer diameter of a blade.
[Brief description of the drawings]
FIG. 1 is a front view of a steel pipe pile according to a first embodiment.
FIG. 2 is a bottom view of the steel pipe pile according to the first embodiment.
FIG. 3 is a sectional view of a principal part taken along line 1-1 in FIG. 2;
FIG. 4 is a front view showing the screw-in depth of the steel pipe pile in the first embodiment.
FIG. 5 is a front sectional view of a main part of a steel pipe pile according to a second embodiment.
FIG. 6 is a partial cross-sectional view of a main part of a steel pipe pile according to a third embodiment.
FIG. 7 is a front view of a main part of a steel pipe pile according to a fourth embodiment.
FIG. 8 is a front view of a main part of a steel pipe pile according to a fifth embodiment.
FIG. 9 is a front view of a main part of a steel pipe pile according to a sixth embodiment.
FIG. 10A is a perspective view of a main part of a steel pipe pile according to a seventh embodiment,
(B) is a bottom view of the steel pipe pile in the seventh embodiment.
FIGS. 11A to 11C are front cross-sectional views of a main part of a reinforcing member according to another embodiment.
FIGS. 12A and 12B are plan views of a reinforcing member according to another embodiment.
FIG. 13A is a front view of a main part of a conventional steel pipe pile,
(B) is a principal part front view which shows the curvature of the blade | wing of the conventional steel pipe pile.
FIG. 14 is a bottom view of a conventional steel pipe pile.
[Explanation of symbols]
11 ... steel pipe pile, 12 ... steel pipe, 15a, 15b, 23a, 23b ... blade,
21 ... a reinforcing member constituting a deformation suppressing structure;
21a: a first reinforcing member constituting a reinforcing member;
21b: second reinforcing member constituting the reinforcing member, 22: outlet, S: flat surface.

Claims (5)

In a steel pipe pile that is screwed into the ground using one or more blades attached to the lower part of the steel pipe,
A steel pipe pile, wherein the one or more blades are provided with a deformation suppressing structure that suppresses deformation of the blades due to a ground reaction force when screwed into the ground. The steel pipe pile according to claim 1, wherein the deformation suppressing structure is a reinforcing member fixed to an outer peripheral edge of the blade so as to collectively cover an entire circumference of one or more blades. A plurality of blades are attached to the lower outer peripheral surface of the steel pipe at the same angle with respect to a plane perpendicular to the central axis of the steel pipe, and are inclined downward in the rotation direction of the steel pipe when screwed into the ground,
2. The steel pipe pile according to claim 1, wherein the deformation suppressing structure includes one or a plurality of reinforcing members interconnecting part or all of the outer peripheral edge of each blade. 3. A reinforcing member for a steel pipe pile blade, which is attached to one or more blades provided at a lower portion of the steel pipe pile and suppresses deformation due to screwing of the blade into the ground,
A steel pipe pile blade reinforcing member formed so as to collectively cover the entire circumference of one or more blades. A reinforcing member for a steel pipe pile blade that is attached to a plurality of blades provided at a lower portion of the steel pipe pile and suppresses deformation due to screwing of the blade into the ground,
A reinforcing member for a steel pipe pile blade formed so that part or all of the outer peripheral edge of each blade can be connected to each other.

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