Utility pole foundation method, and steel pipe frame and attachment used for utility pole foundation method

Abstract

To provide an electric pole foundation method capable of reducing time and labor by simultaneously performing a process for burying a steel pipe frame in the ground and a process for excavating a space in the steel pipe frame.SOLUTION: An electric pole foundation method according to the present invention includes a step of fixing an attachment 50 to a connection rod 5 that rotates together with rotation of an auger motor, a step of fixing an excavation screw to the connection rod 5, a step of engaging a hooking pin 63 provided on the attachment 50 with a notch 110 provided on an upper end side of a steel pipe frame 100, and a step of embedding the steel pipe frame 100 in the ground together with the excavation screw by rotating the steel pipe frame 100 clockwise in a plan view by the auger motor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a utility pole foundation construction method used when installing a utility pole on the ground, and to a steel pipe frame and attachment used in the utility pole foundation construction method. [Background technology]

[0002] Conventionally, the foundation construction method used when erecting utility poles on the ground has been to bury a cylindrical steel pipe frame in the ground, install the utility pole inside the steel pipe frame, and then pour concrete between the steel pipe frame and the utility pole to secure the pole in place.

[0003] As an example of such a utility pole foundation construction method, Patent Document 1 (JP 2016-113800 A) proposes a construction method in which a pilot hole 13 having an inner diameter equal to or smaller than the outer diameter of a thin-walled steel pipe 2 is excavated into the ground G using a screw auger 7 of a pole erection vehicle 12, and then the steel pipe 5 for reinforcing the lower part of the foundation steel pipe 1 is inserted into the pilot hole 13 while facing downward. Special claws 8 attached to the tip of the screw auger 7 are engaged with fittings 9 attached to the inner surface of the steel pipe 5 for reinforcing the lower part. The foundation steel pipe 1 is then rotated and pushed into the pilot hole 13 in the ground. A circular bottom plate 14 is then inserted into the foundation steel pipe 1 and placed on the ground within the foundation steel pipe 1. A column 15 is then inserted into the foundation steel pipe 1 and erected. After the column 15 is maintained vertically, concrete 16 is poured between the foundation steel pipe 1 and the column 15 to secure it in place. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-113800 A Summary of the Invention [Problem to be solved by the invention]

[0005] The conventional technology described in Patent Document 1 has the following problems. (1) The problem is that a step of drilling a pilot hole 13 is required as a preliminary step before inserting the foundation steel pipe 1 into the ground, which requires time and effort. (2) The foundation steel pipe 1 must be a complex steel pipe with an upper reinforcing steel pipe 4 fixed to the upper end and a lower reinforcing steel pipe 5 connected to the lower end, which increases the cost of the foundation steel pipe 1. (3) In the prior art, in order to transmit the rotation of the screw auger 7 to the foundation steel pipe 1, the screw auger 7 is inserted into the foundation steel pipe 1, and the dedicated claws 8 of the attachment 10 connected to the screw auger 7 are engaged with the engagement grooves 9b of the engagement member 9. However, the work of engaging the dedicated claws 8 with the engagement member 9 must be performed inside the lower side of the foundation steel pipe 1, which is difficult for workers to reach, resulting in poor workability.

[0006] While it is expected that an increasing number of utility poles will need to be replaced due to aging, a future decline in the labor force is also predicted. To address this situation, there is a need for a cheaper, easier, mechanized utility pole foundation construction method, but conventional technology has had various issues as mentioned above. [Means for solving the problem]

[0007] In order to solve such problems, the utility pole foundation construction method of the present invention is characterized by comprising the steps of: fixing an attachment to a connecting rod that rotates with the rotation of an auger motor; fixing an excavation screw to the connecting rod; engaging a hook pin provided on the attachment with a notch provided on the upper end side of a steel pipe frame; and burying the steel pipe frame together with the excavation screw into the ground by rotating the steel pipe frame clockwise in a plan view using the auger motor.

[0008] Furthermore, the utility pole foundation construction method according to the present invention is characterized by further comprising a step of releasing the hook pin of the attachment from the cutout portion of the steel pipe frame, and a step of raising the excavation screw while rotating the excavation screw counterclockwise in a plan view by the auger motor.

[0009] The utility pole foundation construction method according to the present invention is characterized by further comprising a step of connecting the upper end side of the steel pipe frame and the lower end side of a second steel pipe frame.

[0010] The utility pole foundation construction method according to the present invention is characterized by further comprising the steps of: engaging a hook pin provided on the attachment with a notch provided on the upper end side of the second steel pipe frame; and rotating the steel pipe frame clockwise in a plan view using the auger motor, thereby burying the steel pipe frame and the second steel pipe frame together with the excavation screw into the ground.

[0011] The steel pipe frame according to the present invention is characterized in that a notch is provided on the upper end side and an excavation tooth portion is provided on the lower end side.

[0012] Moreover, the steel pipe frame according to the present invention is characterized in that the cutout portions are L-shaped and provided at three locations.

[0013] The steel pipe frame according to the present invention is characterized in that threaded holes having threaded portions on their inner peripheries are provided on both sides of the cutout portion.

[0014] The attachment according to the present invention is characterized in that it comprises a rod receiving portion having a rectangular through hole, an arm portion extending in multiple directions from the rod receiving portion, an arc-shaped end portion provided at the tip side of the arm portion, and a hook pin provided at the arc-shaped end portion.

[0015] The attachment according to the present invention is also characterized in that the arc-shaped end portion is provided with a through-hole used for fixing an extension member. [Effects of the Invention]

[0016] According to the utility pole foundation construction method of the present invention, the process of burying the steel pipe frame in the ground and the process of excavating the space inside the steel pipe frame and removing the soil can be carried out simultaneously, thereby reducing time and labor.

[0017] Furthermore, according to the utility pole foundation construction method of the present invention, the structure of the steel pipe frame is relatively simple, and the cost of the steel pipe frame can be reduced.

[0018] Furthermore, according to the utility pole foundation construction method of the present invention, the work of engaging the hook pin of the attachment with the cutout portion of the steel pipe frame in order to transmit the rotation of the auger motor to the steel pipe frame can be performed on the upper end side of the steel pipe frame, which is within reach of the worker and makes the work easier.

[0019] Furthermore, the steel pipe frame according to the present invention has a relatively simple structure, while being able to provide good workability in the utility pole foundation construction method.

[0020] Furthermore, the attachment according to the present invention can be easily attached to and detached from the connecting rod, providing good workability in the utility pole foundation construction method.

[0021] Furthermore, the attachment according to the present invention can accommodate construction using steel pipe frames of different diameters. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram schematically illustrating a pole erection vehicle 1 used in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 3] 1 is a perspective view of an attachment 50 used in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 4] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 5] 10 is a perspective view showing a state in which the hook pin 63 of the attachment 50 is engaged with the notch 110 of the steel pipe frame 100. FIG. [Figure 6] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 7] 10 is a diagram illustrating the rotation direction of the steel pipe frame 100. FIG. [Figure 8] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 9] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 10] FIG. 2 is a perspective view of a second steel pipe frame 200 used in the utility pole foundation construction method according to the embodiment of the present invention. [Figure 11] 10 is a perspective view showing a state in which an attachment 50 is engaged with a second steel pipe frame 200 connected to a steel pipe frame 100. FIG. [Figure 12] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 13] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 14] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 15] FIG. 1 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. [Figure 16] FIG. 10 is a perspective view of an attachment 50 used in a utility pole foundation construction method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be described below with reference to the embodiments and drawings. One of the major features of the utility pole foundation construction method according to the present invention is that, in the foundation work for erecting a utility pole on the ground, the process of burying a steel pipe frame 100 in the ground and the process of excavating the space inside the steel pipe frame 100 and removing soil can be carried out simultaneously. In the following embodiments, the erection of a utility pole for use in a railway will be described as an example, but the utility pole foundation construction method according to the present invention can also be widely used in fields other than the railway field.

[0024] In railway construction, it is preferable to use a pole erection vehicle 1 as shown in Figure 1 when carrying out the utility pole foundation construction method of the present invention. The pole erection vehicle 1 is mounted on track R and is used to construct utility pole foundations within the movable range of a boom 3. An auger motor 4 is provided at the tip of the boom 3, and rotational force is output from this auger motor 4. A connecting rod 5 is attached to the shaft to which the rotational force of the auger motor 4 is output. As a result, the connecting rod 5 rotates together with the rotation output from the auger motor 4. The connecting rod 5 may be attached directly to the auger motor 4, or may be attached via a connecting metal fitting or the like.

[0025] The connecting rod 5 is a rectangular rod with a square cross section cut perpendicular to the longitudinal direction (the vertical direction on the paper in FIG. 1), and has a plurality of through holes 6 formed at predetermined intervals along the longitudinal direction. The distance between adjacent through holes 6 can be, for example, 300 mm. By using the through holes 6, an attachment 50 or a drilling screw 7 can be attached to and detached from the connecting rod 5.

[0026] 2 is a diagram schematically illustrating one step in a utility pole foundation construction method according to an embodiment of the present invention. The steps of the utility pole foundation construction method according to the present invention will be described below in order. First, an attachment 50 according to the present invention is attached to the highest through hole 6 in the connecting rod 5. Note that the through hole 6 to which the attachment 50 is attached does not necessarily have to be the highest through hole 6, but it is preferable to use the highest through hole 6 in the early stages of construction of the utility pole foundation.

[0027] Here, the structure of attachment 50 according to the present invention will be described with reference to Figure 3. Attachment 50 has a rod receiving portion 53 and arm portions 60 extending from rod receiving portion 53 in three directions.

[0028] A rectangular through-hole 54 that penetrates in the vertical direction is provided in the rod receiving portion 53. Two opposing through-holes 55 (one of the through-holes is not shown in FIG. 3) are provided on the side surface of the rod receiving portion 53, and a cylindrical member such as a bolt can be inserted from one through-hole 55 to the other through-hole 55 via the rectangular through-hole 54.

[0029] An arc-shaped end portion 61 is provided on the tip side of the arm portion 60. This arc-shaped end portion 61 is provided with a hook pin 63 protruding from the arc-shaped end portion 61 and a through-hole 65 penetrating the arc-shaped end portion 61. The hook pin 63 and the through-hole 65 in the arc-shaped end portion 61 are sized to correspond to a structure provided on the upper side of the steel pipe frame 100.

[0030] When the hook pin 63 is engaged with the cutout portion 110 of the steel pipe frame 100, the through hole 65 can be used to screw a bolt (not shown) into the threaded hole 115 to more firmly secure the attachment 50 to the steel pipe frame 100, but the use of the through hole 65 is not essential.

[0031] Returning to Figure 2, the drilling screw 7 is attached by using a through hole below the through hole 6 to which the attachment 50 is attached (usually the through hole 6 one hole below the through hole 6 to which the attachment 50 is attached).

[0032] The process shown in Figure 4 shows the state in which the steel pipe frame 100 is attached to the attachment 50. In the diagrams of each process, including Figure 4, the steel pipe frame 100 is shown transparently to show the inside of the steel pipe frame 100. Also, the diagrams of each process are schematic diagrams and are not to scale. In reality, the outer periphery of the drilling screw 7 is sized to fit approximately within the inner periphery of the steel pipe frame 100.

[0033] Here, the structure of the steel pipe frame 100 according to the present invention will be described with reference to Fig. 5. Fig. 5 is a perspective view showing the state when the grappling pin 63 of the attachment 50 is engaged with the notched portion 110 of the steel pipe frame 100.

[0034] The steel pipe frame 100 is used by being buried in the ground. At this time, the soil inside the steel pipe frame 100 is removed, and a space is formed inside the steel pipe frame 100. The utility pole is set upright in the space inside the steel pipe frame 100, and concrete or the like is poured into the space to fix the utility pole in place.

[0035] By using the steel pipe frame 100 according to the present invention, in the utility pole foundation construction method of the present invention, the process of burying the steel pipe frame 100 in the ground and the process of excavating the space inside the steel pipe frame 100 and removing soil are carried out simultaneously. For this purpose, L-shaped cutout portions 110 are provided at three locations on the upper end circumference of the steel pipe frame 100, into which the grappling pins 63 provided on the attachment 50 can be engaged. Meanwhile, excavation teeth 130 are provided at the lower end of the steel pipe frame 100, which cut through the soil when the steel pipe frame 100 is advanced into the ground. In addition, threaded holes 115 having threaded portions on the inner circumference are provided on both sides of the three cutout portions 110. These threaded holes 115 are used when connecting the steel pipe frame 100 to a second steel pipe frame 200, which will be described later.

[0036] In the example of this embodiment, the shape of the notch 110 is L-shaped, but the shape of the notch 110 does not need to be limited to this.

[0037] In the present invention, three hook pins 63 are provided on the attachment 50, and three notched portions 110 are provided on the steel pipe frame 100, but the numbers of hook pins 63 and notched portions 110 are not limited to these. In the case of this embodiment, when the steel pipe frame 100 is buried in the ground while being rotated, the load applied to one hook pin 63 is 989.7 kgf. If it is necessary to further distribute this load, the number of hook pins 63 and notched portions 110 can be four or more, for example.

[0038] In the utility pole foundation construction method according to the present invention, in order to transmit the rotation of the auger motor 4 to the steel pipe frame 100, the hook pin 63 of the attachment 50 is engaged with the cutout portion 110 of the steel pipe frame 100, but this operation can be performed on the upper end side of the steel pipe frame 100, where workers can reach it and the work is easy to do.

[0039] Once the attachment 50 has been set on the steel pipe frame 100 as described above, in the subsequent process shown in Figure 6, the auger motor 4 is rotated clockwise in a plan view, while the excavation screw 7 excavates the soil inside the steel pipe frame 100, burying the steel pipe frame 100 in the ground.

[0040] The rotation direction of the steel pipe frame 100 in the utility pole foundation construction method according to the present invention will be described with reference to Fig. 7. Fig. 7(A) is a diagram schematically showing the steel pipe frame 100, and Fig. 7(B) is a diagram schematically showing the excavation tooth portion 130 of the steel pipe frame 100. On the lower end side of the steel pipe frame 100, the end portion from which the excavation tooth portion 130 extends is defined as an imaginary column edge 120.

[0041] For each of the excavation teeth 130, a first end 131 that is the greatest distance from the imaginary cylinder edge 120 and a second end 132 that is the smallest distance from the imaginary cylinder edge 120 are defined. Here, as shown in FIG. 7(B), when the steel pipe frame 100 is excavated into the ground, the steel pipe frame 100 is rotated so that the first end 131 is at the front. That is, as shown in FIG. 7(A), in the process of burying the steel pipe frame 100 into the ground together with the excavation screw 7, the steel pipe frame 100 is rotated clockwise in a plan view. By rotating the steel pipe frame 100 so that the first end 131 of the excavation teeth 130 is at the front, efficient excavation is possible.

[0042] 8 is a diagram illustrating the process of removing the soil after it has been excavated inside the steel pipe frame 100 by the excavation screw 7. First, the grappling pin 63 of the attachment 50 is removed from the cutout portion 110 of the steel pipe frame 100. This frees the steel pipe frame 100 from the rotational force of the auger motor 4.

[0043] Next, the excavation screw 7 is raised while being rotated counterclockwise in a plan view by the auger motor 4. This makes it possible to discharge the soil excavated within the steel pipe frame 100 while it remains attached to the excavation screw 7.

[0044] Next, as shown in Fig. 9, a step of connecting a second steel pipe frame 200 to the upper end side of the steel pipe frame 100 is carried out. Fig. 10 is a perspective view of the second steel pipe frame 200 used in the utility pole foundation construction method according to an embodiment of the present invention. Connecting pieces 220 are provided at three locations on the lower end side of the second steel pipe frame 200. The connecting pieces 220 are provided with threaded holes 225 having threaded portions on their inner peripheries so as to correspond to the threaded holes 115 of the steel pipe frame 100.

[0045] Furthermore, on the upper end side of the second steel pipe frame 200, L-shaped cutout portions 110 into which the hook pins 63 provided on the attachment 50 can be engaged are provided at three locations on the periphery of the upper end of the second steel pipe frame 200. The configuration of the cutout portions 110 is the same as that of the upper end side of the steel pipe frame 100.

[0046] 11 is a perspective view showing a state in which the second steel pipe frame 200 has been connected to the steel pipe frame 100. When connecting the second steel pipe frame 200 to the steel pipe frame 100, the positions of the threaded holes 115 of the steel pipe frame 100 and the threaded holes 225 of the connecting pieces 220 of the second steel pipe frame 200 are aligned, and the bolts (not shown) are screwed into both the threaded holes 225 and 115 with the heads of the bolts facing outward.

[0047] The steel pipe frame 100 and the second steel pipe frame 200 are connected only by the screwing force of the bolts and their respective threaded holes, without using nuts or the like. The bolts are long enough not to protrude from the inner peripheral surface of the steel pipe frame 100. This configuration is used because it is necessary to pass the drilling screws 7 inside the steel pipe frame 100, and nuts or the like or the bolt tips must not come into contact with the drilling screws 7.

[0048] Here, it was estimated that a load of 494.8 kgf would be applied to each bolt used to connect the steel pipe frame 100 and the second steel pipe frame 200. The allowable shear force of an M20 bolt is 2,480 kgf, and a safety factor of 2.5 or more can be ensured, so M20 bolts are used in this embodiment, but M16 bolts can also be used in terms of strength.

[0049] In the utility pole foundation construction method according to the present invention, the second steel pipe frame 200 is connected to the steel pipe frame 100 in an intermediate step. That is, in the utility pole foundation construction method according to the present invention, a steel pipe frame having a length equal to the sum of the steel pipe frame 100 and the second steel pipe frame 200 is not used. The reason why the second steel pipe frame 200 is connected to the steel pipe frame 100 in an intermediate step in this manner is to enable the use of an excavation screw 7 that is not relatively long.

[0050] In the process shown in Fig. 9, in addition to connecting the second steel pipe frame 200 to the steel pipe frame 100, the position at which the excavation screw 7 is attached to the connecting rod 5 is changed. More specifically, the excavation screw 7 is attached to the through hole 6 provided on the lower side of the connecting rod 5, so that the second steel pipe frame 200 corresponds to the length of the added steel pipe frame 100. Note that it is desirable to set the attachment position of the excavation screw 7 to the connecting rod 5 at a position where the excavation screw 7 does not excessively protrude below the steel pipe frame 100, thereby preventing unnecessary excavation and minimizing the need for backfilling work as much as possible.

[0051] In the process shown in Fig. 12, the hook pin 63 of the attachment 50 is engaged with the notch 210 of the second steel pipe frame 200 to transmit the rotation of the auger motor 4 to the second steel pipe frame 200. This work can be performed on the upper end side of the steel pipe frame 100, where workers can reach and work easily. Fig. 11 shows how the attachment 50 is engaged with the second steel pipe frame 200 connected to the steel pipe frame 100.

[0052] In the process shown in Figure 13, the auger motor 4 is rotated clockwise in a plan view, while the excavation screw 7 excavates the soil within the second steel pipe frame 200 and the steel pipe frame 100, and the second steel pipe frame 200 and the steel pipe frame 100 are buried in the soil.

[0053] After the step in Figure 13, the second steel pipe frame 200 and the steel pipe frame 100 are buried until they reach their designed positions, and along the way, the soil inside the second steel pipe frame 200 and the steel pipe frame 100 is removed as needed. In the soil removal step, the grappling pin 63 of the attachment 50 is released from the cutout portion 210 of the second steel pipe frame 200. Next, the excavation screw 7 is raised while being rotated counterclockwise in a plan view by the auger motor 4. The soil excavated inside the second steel pipe frame 200 and the steel pipe frame 100 is removed while remaining attached to the excavation screw 7.

[0054] The second steel pipe frame 200 and the steel pipe frame 100 are buried until they reach their designed position by appropriately repeating the steps of excavating the soil inside the second steel pipe frame 200 and the steel pipe frame 100 while burying them, and separating the second steel pipe frame 200 from the attachment 50, raising the excavation screw 7, and removing the excavated soil.

[0055] Figure 14 shows the state in which the second steel pipe frame 200 and the steel pipe frame 100 have been buried to their designed positions, the soil has been removed from inside the second steel pipe frame 200 and the steel pipe frame 100, and then a bottom plate 8 has been installed below the steel pipe frame 100. In the subsequent step in Figure 15, the utility pole 10 is placed upright on the bottom plate 8, and concrete 11 is poured into the space between the utility pole 10 and the second steel pipe frame 200 / steel pipe frame 100 to fix the utility pole 10 in place.

[0056] As described above, according to the utility pole foundation construction method of the present invention, the process of burying the steel pipe frame 100 in the ground and the process of excavating the space inside the steel pipe frame 100 and removing the soil can be carried out simultaneously in parallel, thereby reducing time and labor.

[0057] Furthermore, according to the utility pole foundation construction method of the present invention, the structure of the steel pipe frame 100 is relatively simple, and the cost of the steel pipe frame 100 can be reduced.

[0058] Furthermore, according to the utility pole foundation construction method of the present invention, the work of engaging the hook pin 63 of the attachment 50 with the cutout portion 110 of the steel pipe frame 100 in order to transmit the rotation of the auger motor to the steel pipe frame 100 can be performed on the upper end side of the steel pipe frame 100, which is within reach of the worker and provides good workability.

[0059] Furthermore, the steel pipe frame 100 according to the present invention has a relatively simple structure, while still providing good workability in the utility pole foundation construction method.

[0060] Furthermore, the attachment 50 according to the present invention can be easily attached to and detached from the connecting rod, providing good workability in the utility pole foundation construction method.

[0061] Next, another embodiment of the present invention will be described. Fig. 16 is a perspective view of an attachment 50 used in a utility pole foundation construction method according to another embodiment of the present invention. Fig. 16(A) shows the state prior to attaching an extension member 80 to the attachment 50 according to another embodiment, and Fig. 16(B) shows the state after the extension member 80 has been attached to the attachment 50 according to another embodiment. Note that components assigned the same reference numbers as those in the previous embodiment have the same configuration as those in the previous embodiment, and therefore their explanation may be omitted.

[0062] Steel pipe frames 100 come in different diameters, such as 609 mm and 507 mm. Therefore, in the attachment 50 according to another embodiment, an extension member 80 is attached to the basic attachment 50 so that it can be used for a utility pole foundation construction method for a steel pipe frame 100 with a larger diameter, in order to accommodate steel pipe frames 100 with different diameters.

[0063] In the attachment 50 according to another embodiment, the three arcuate ends 61 are provided with hook pins 63 and through holes 65 as well as through holes 67 for attaching extension members 80 .

[0064] In another embodiment, three extension members 80 are prepared that can be attached to and detached from the arc-shaped end portion 61 of the attachment 50. The extension members 80 have arc-shaped base portions 81 that have a curved surface that fits along the outer peripheral surface of the arc-shaped end portion 61 of the attachment 50. The curved surface of the extension members 80 is provided with recesses 82 into which the hook pins 63 of the attachment 50 can be inserted.

[0065] A stepped through-hole 87 for mounting is provided in the arc-shaped base 81 of the extension member 80, and the extension member 80 can be fixed to the attachment 50 by aligning the through-hole 67 on the attachment 50 side with this stepped through-hole 87 and fastening them with bolts, nuts, etc. Also, a through-hole 85 corresponding to the through-hole 65 on the attachment 50 side is provided in the arc-shaped base 81 of the extension member 80.

[0066] The extension member 80 is also provided with a hook pin 83, which allows the attachment 50 to which the extension member 80 is attached to engage and disengage the hook pin 83 with the cutout portion 110 of the steel pipe frame 100 with a larger diameter.

[0067] According to the other embodiment of the present invention as described above, it is possible to enjoy the same effects as the previous embodiment, and also to accommodate construction using steel pipe frames 100 of different diameters. [Explanation of symbols]

[0068] 1...Pole erecting car 3. Boom 4. Auger motor 5. Connecting rod 6. Through hole 7. Drilling screw 8...Bottom plate 10. Utility pole 11. Concrete 50···Attachment 53 Rod receiving part 54 Square through hole 55...Through hole 60···Arm section 61 Arc-shaped end 63···Hook pin 65...Through hole 67···(for attaching extension parts) through hole 80... Extension material 81 Arc-shaped base 82 Recess 83···Hook pin 85...Through hole 87 Stepped through hole 100···Steel pipe frame 110...Notch 115...Threaded hole 120... Virtual cylinder edge 130 Excavation teeth 131...1st end 132...2nd end 200···Second steel pipe frame 210...Notch 215...Threaded hole 220...Connection piece 225...Threaded hole R...orbital

Claims

1. fixing the attachment to a connecting rod that rotates with the rotation of the auger motor; securing a drilling screw to the connecting rod; a step of engaging a hook pin provided on the attachment with a notch provided on an upper end side of the steel pipe frame; and a step of burying the steel pipe frame together with the excavation screw into the ground by rotating the steel pipe frame clockwise in a plan view using the auger motor.

2. a step of removing the grappling pin of the attachment from the notch portion of the steel pipe frame; The utility pole foundation construction method according to claim 1, further comprising a step of lifting the excavation screw while rotating the excavation screw counterclockwise in a plan view by the auger motor.

3. 2. The utility pole foundation construction method according to claim 1, further comprising a step of connecting the upper end side of the steel pipe frame and the lower end side of a second steel pipe frame.

4. a step of engaging a hook pin provided on the attachment with a notch provided on an upper end side of the second steel pipe frame; The utility pole foundation construction method according to claim 3, further comprising a step of burying the steel pipe frame and the second steel pipe frame together with the excavation screw into the ground by rotating the steel pipe frame clockwise in a plan view using the auger motor.

5. A steel pipe frame used in a utility pole foundation construction method, characterized in that it has a notch on the upper end side and an excavation tooth on the lower end side.

6. 6. The steel pipe frame used in the utility pole foundation construction method according to claim 5, wherein the cutout portions are L-shaped and provided at three locations.

7. 7. The steel pipe frame used in the utility pole foundation construction method according to claim 6, wherein a threaded hole having a threaded portion on the inner periphery is provided on both sides of the cutout portion.

8. a rod receiving portion having a rectangular through hole; and arm portions extending in multiple directions from the rod receiving portion; An attachment used in a utility pole foundation construction method, characterized by comprising an arc-shaped end portion provided at the tip side of the arm portion and a hook pin provided at the arc-shaped end portion.

9. 9. An attachment for use in a utility pole foundation construction method according to claim 8, wherein the arc-shaped end portion is provided with a through-hole used for fixing an extension member.

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