Abstract
An object of the present invention is to provide a pole erection method capable of efficiently and safely erecting a utility pole with a small number of operators even in a construction environment in which heavy machines cannot be used.
The pole erection method according to the present invention includes preparing a structure 60 having a cylindrical shape in which, when the structure is erected perpendicularly to the ground with one end 60a facing down, a part of an edge 61a at the other end 60b is higher than the other part of the edge 61b (step S01), burying one end 60a of the structure 60 in the ground (step S02), placing a lower end portion 10a-1 of a utility pole 10a lying on the ground on the other part of the edge 61b of the structure 60 (step S03), pressing the lower end portion 10a-1 of the utility pole 10a against an inner wall 62 (step S04), and lifting up an upper end portion 10a-2 of the utility pole 10a with the other part of the edge 61b as a fulcrum while pressing the lower end portion 10a-1 of the utility pole 10a against the inner wall 62, and sliding down the utility pole 10a into a cavity 63 of the structure 60 to erect the pole (step S05).
Claims
1. A pole erection method comprising: preparing a structure having a cylindrical shape in which, when the structure is erected perpendicularly to a ground with one end facing down, a part of an edge at another end is higher than another part of the edge; burying the one end of the structure in the ground; placing a lower end portion of a utility pole lying on the ground on the other part of the edge facing the part of the edge at the other end of the structure; pressing the lower end portion of the utility pole against an inner wall on a side of the part of the edge of the structure; and lifting up an upper end portion of the utility pole with the other part of the edge as a fulcrum while pressing the lower end portion of the utility pole against the inner wall, and sliding down the utility pole into a cavity of the structure to erect the utility pole.
2. The pole erection method according to claim 1, wherein the edge of the other end of the structure has a shape including a cut surface obtained by linearly and obliquely cutting the structure with respect to a central axis.
3. The pole erection method according to claim 1, wherein the edge of the other end of the structure has a shape including a cut surface obtained by obliquely cutting the structure in a curved shape with respect to the central axis.
4. The pole erection method according to claim 1, wherein the edge of the other end of the structure has a stepped shape including the part of the edge and the other part of the edge.
5. The pole erection method according to claim 4, wherein the other part of the edge has a wedge-shaped notch in a central portion.
6. The pole erection method according to claim 1, wherein the part of the edge has a constant height.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0036] FIG. 1 is a diagram illustrating a pole erection method using a heavy machine.
[0037] FIG. 2 is a diagram illustrating a pole erection method using human power.
[0038] FIG. 3 is a diagram illustrating a structure used in a pole erection method according to the present invention.
[0039] FIG. 4 is a diagram illustrating a structure used in the pole erection method according to the present invention.
[0040] FIG. 5 is a diagram illustrating the pole erection method according to the present invention.
[0041] FIG. 6 is a diagram illustrating the pole erection method according to the present invention.
[0042] FIG. 7 is a diagram illustrating the pole erection method according to the present invention.
[0043] FIG. 8 is a diagram illustrating the pole erection method according to the present invention.
[0044] FIG. 9 is a diagram illustrating a structure used in the pole erection method according to the present invention.
[0045] FIG. 10 is a diagram illustrating a structure used in the pole erection method according to the present invention.
[0046] FIG. 11 is a diagram illustrating a structure used in the pole erection method according to the present invention.
DESCRIPTION OF EMBODIMENTS
[0047] Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. Note that components having the same reference numerals in the present specification and the drawings indicate the same components.
First Embodiment
[0048] FIG. 7 is a flowchart illustrating a pole erection method of the present embodiment. The pole erection method of the present embodiment includes: [0049] preparing a structure 60 having a cylindrical shape in which, when the structure is erected perpendicularly to the ground with one end 60a facing down, a part of an edge 61a at the other end 60b is higher than the other part of the edge 61b (step S01); [0050] burying one end 60a of the structure 60 in the ground (step S02); [0051] placing a lower end portion 10a-1 of a utility pole 10a lying on the ground on the other part of the edge 61b facing the part of the edge 61a at the other end 60b of the structure 60 (step S03); [0052] pressing the lower end portion 10a-1 of the utility pole 10a against an inner wall 62 on the side of the part of the edge 61a of the structure 60 (step S04); and [0053] lifting up an upper end portion 10a-2 of the utility pole 10a with the other part of the edge 61b as a fulcrum while pressing the lower end portion 10a-1 of the utility pole 10a against the inner wall 62, and sliding down the utility pole 10a into a cavity 63 of the structure 60 to erect the pole (step S05).
[0054] FIGS. 3 and 4 are diagrams illustrating an example of the structure 60. FIG. 3 is a perspective view of structure 60, and FIG. 4 is a three-face view of the structure 60. (A) is a top view, (B) is a front view, and (C) is a side view. The structure 60 is a cylindrical object having a hollow center. The structure 60 has a height difference such that, when it is erected perpendicularly to the ground with one end 60a facing down, the part of the edge 61a at the other end 60b is higher than the other part of the edge 61b. Here, the part of the edge 61a and the other part of the edge 61b are at diagonal positions.
[0055] The edge of the other end 60b of the structure 60 of the present embodiment has a shape including a cut surface obtained by obliquely cutting the structure 60 in a curved shape with respect to a central axis. As shown in FIG. 4 (C), in the case of the structure 60 of the present embodiment, the part of the edge 61a and the other part of the edge 61b are connected by a gentle curve. This has an effect that when a utility pole which will be described later is placed on the other end 60b, the utility pole slides and settles on the other part of the edge 61b by the weight thereof. Note that, as illustrated in FIG. 3, it is desirable that the structure 60 be bilaterally symmetrical with respect to a plane defined by the central axis of the structure 60 and a straight line X-X. The one having a higher height difference has a constant surface for replacement of a backing plate.
[0056] Further, the part of the edge 61a has a constant height in the circumferential direction, and maintains the area of the inner wall 62 to some extent. This is for the purpose of providing a function of a backing plate for pressing the lower end portion 10a-1 against the inner wall 62.
[0057] A pole erection method of the present embodiment will be described in detail with reference to FIG. 8.
[0058] FIGS. 8 (1) and 8 (2) illustrate the same processes as STEP 1 and STEP 2 in FIG. 1. Note that a reference numeral 59 denotes a hole drilled by an operator 13 in a prospected hole 55. Unlike the hole 58 described with reference to FIG. 2, the structure 60 has functions of a backing plate 56 and a sliding slope 8b, and thus the amount of excavation of the hole 59 corresponds to only the cylindrical structure 60.
[0059] FIG. 8 (3) corresponds to steps S01 and S02 in FIG. 7 and is a process of preparing the structure 60 and burying the structure in the hole 59. Here, instead of burying the entire structure 60 in the ground 50, a part of the structure 60 on the side of one end 60a is buried. That is, the other end 60b of the structure 60 protrudes to the ground surface. The structure 60 serves as a base of the utility pole 10a.
[0060] FIG. 8 (4) corresponds to step S03 in FIG. 7 and is a process of placing the lower end portion 10a-1 of the utility pole 10a on the other part of the edge 60b of the structure 60. FIG. 5 is a diagram illustrating this state in detail. Since the other end 60b of the structure 60 is constituted by the part of the edge 61a and the other part of the edge 61b having different heights, and the edges are connected by a gentle curve, when the lower end portion 10a-1 of the utility pole 10a is placed on the structure 60, the utility pole 10a slides and settles on the other part of the edge 61b by the weight thereof.
[0061] FIG. 8 (5) corresponds to step S04 in FIG. 7, in which the operator 13 lifts up the upper end portion 10a-2 of the utility pole 10 and presses the lower end portion 10a-1 against the inner wall 62 on the side of the part of the edge 61a of the structure 60.
[0062] FIGS. 8 (6) and 8 (7) correspond to step S05 in FIG. 7. As shown in FIG. 8 (6), the operator 13 approaches the structure 60 while pressing the lower end portion 10a-1 of the utility pole 10a against the inner wall 62, and raises the upper end portion 10a-2 of the utility pole 10a with the other part of the edge 61b as a fulcrum. When the utility pole 10a rises up to a certain angle with respect to the ground 50, the lower end portion 10a-1 slides down into the cavity 63 of the structure 60 by the weight thereof and thus the utility pole 10a can be erected (refer to FIGS. 8 (7) and FIG. 6).
[0063] In this way, by using the structure 60, it is not necessary to excavate the hole 58 having a large area for installing the sliding slope or the backing plate described with reference to FIG. 2 when the utility pole 10a is erected by human power. That is, efficient pole erection can be performed by using the structure 60. Furthermore, since the structure 60 supports the utility pole 10a and supports construction, labor of the operator 13 can be reduced and safe work can be realized with a small number of people. When the material of the utility pole is lightweight such as plastic, even one operator can erect the pole.
Variation in Shape of Structure
[0064] Although an example of the shape of the structure 60 has been described with reference to FIGS. 3 and 4, the structure 60 may have other shapes. FIGS. 9 to 11 are three-face views illustrating shapes of the structure 60. In any of the figures, (A) is a top view, (B) is a front view, and (C) is a side view.
[0065] The edge of the other end 60b of the structure 60 in FIG. 9 has a shape including a cut surface obtained by linearly and obliquely cutting the structure 60 with respect to the central axis. The structure 60 in this figure has a shape like a bamboo cut at an angle. In the case of such a shape, the positions of the part of the edge 61a, the other part of the edge 61b, and the inner wall 62 are not clear, but when the structure 60 is erected on the ground with one end 60a facing down, a region including the highest portion of the other end 60b is the part of the edge 61a, and a region including the lowest portion of the other end 60b is the other part of the edge 61b. When viewed from the front, an inner wall portion under the part of the edge 61a viewed from the front is the inner wall 62.
[0066] The edge of the other end 60b of the structure 60 in FIG. 10 has a stepped shape including the part of the edge 61a and the other part of the edge 61b. In other words, when the structure 60 is erected on the ground with the one end 60a facing down, the part of the edge 61a and the other part of the edge 61b having a height difference therebetween are horizontal with respect to the ground, and the edge between the part of the edge 61a and the other part of the edge 61b is vertical with respect to the ground.
[0067] As illustrated in FIG. 11, the structure 60 in FIG. 10 may have a wedge-shaped notch 61c at the central portion of the other part of the edge 61b.
[0068] The structure 60 of any of the three types of shapes described herein may be used in the same procedure as in FIG. 8 as an efficient pole erection method.
REFERENCE SIGNS LIST
[0069] 10, 10a Utility pole [0070] 10a-1 Lower end portion [0071] 10a-2 Upper end portion [0072] 13 Operator [0073] 15 Heavy machine [0074] 50 Ground [0075] 55 Prospected hole [0076] 56 Backing plate [0077] 58 Hole [0078] 58a Main hole [0079] 58b Sliding slope [0080] 60 Structure [0081] 60a One end [0082] 60b Other end [0083] 61a Part of edge [0084] 61b Other part of edge [0085] 61c Notch [0086] 62 Inner wall [0087] 63 Cavity
