Repair method for existing steel pipe columns

Abstract

To provide a repair method for existing steel pipe columns that is simple and reduces construction time, regardless of the skill level of the construction technician.SOLUTION: A repair method for existing steel pipe columns erected in concrete or base courses comprises a step of attaching a protective steel plate to a lower end of the steel pipe column such that a lower end of the protective steel plate contacts the concrete or base course, without chipping the concrete or base course away.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for repairing an existing steel pipe pole. [Background technology]

[0002] BACKGROUND ART Steel pipe poles have conventionally been used as supports for existing utility poles, overhead power line poles, guardrails, and the like.

[0003] Such steel pipe columns (hereinafter referred to as "steel pipe columns" in this specification) are constructed with specifications such as zinc plating or a painted coating layer formed on top of the zinc plating. Furthermore, the embedded portion of the steel pipe column (the portion at the ground surface) is fixed to the ground surface using foot-hardening concrete or the like. This portion at the ground surface of the steel pipe column is prone to stagnation of water and dust, and is prone to rust due to the excrement and urine of dogs and other animals. For this reason, regular painting maintenance is carried out, and rusted areas are repaired by covering the portion at the ground surface with concrete.

[0004] Various methods are known for repairing such steel pipe poles, and for example, the repair methods described in Patent Documents 1 and 2 are known.

[0005] The repair method described in Patent Document 1 involves excavating the ground around the steel pipe pole to an extent that will allow the tubular repair cover to fit, exposing the ground-level portion, and then hinge-connecting the tubular repair cover to the top of the steel pipe pole to form the tubular repair cover.The tubular repair cover is then pushed down to the ground-level portion, and then a filler material is filled into the gap between the steel pipe pole and the tubular repair cover.

[0006] This construction allows for easy repair of corrosion at the base of steel pipe poles, preventing disasters caused by the collapse of such poles, and in particular reducing the costs required for repairs and rebuilding. Furthermore, by welding the connecting small-diameter steel pipes to the inside of the tubular repair cover so that they do not protrude outside the cover, and further by welding short connecting small-diameter steel pipes to the ends so that the upper and lower ends of the cover do not become weak points in terms of strength despite the hinge connection, it is possible to reduce costs, shorten construction time, and improve strength and reliability.

[0007] In addition, the repair method described in Patent Document 2 involves wrapping a waterproof and weather-resistant ultraviolet-curing fiber-reinforced resin sheet around the damaged or corroded part of the metal support, adhesively hardening it, and then covering the top of it with a tubular reinforcing material that corresponds to the cross section of the support.

[0008] With this configuration, an ultraviolet-curing resin sheet is wrapped around the corroded or damaged parts of the metal support, adhesively hardened, and then the upper side is covered with a tubular reinforcing material that corresponds to the cross section of the support to repair it, thereby preventing the support from collapsing at low cost.Furthermore, because an ultraviolet-curing fiber-reinforced resin sheet is used, repair work can be completed in a short time, and a support structure with excellent durability can be provided. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-360250 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-213635 Summary of the Invention [Problem to be solved by the invention]

[0010] However, conventional methods for repairing existing steel pipe poles require excavating concrete or the like at the ground level to expose the ground level of the steel pipe pole. In the case of repair methods that involve excavating concrete (hereinafter also referred to as "drilling") in this specification, the excavated area must be backfilled, which is time-consuming and requires a curing period for the backfilled concrete. In particular, when repairs are made to railway overhead line poles, the work must be done at night, outside of railway operating hours, which places constraints on the work time, making it difficult to carry out such repair methods.

[0011] Furthermore, conventional repair methods sometimes require painting the ground-level portion of existing steel pipe poles, which can lead to problems such as difficulty in ensuring the required film thickness and uneven paint.Furthermore, these tasks often rely on the skill of the worker, making them difficult to perform easily.

[0012] Therefore, the present invention has been made in consideration of the above problems, and aims to provide a repair method for existing steel pipe poles that is simple and can shorten the construction time, regardless of the skill of the construction engineer. [Means for solving the problem]

[0013] The method for repairing an existing steel pipe pole of the present invention is a method for repairing an existing steel pipe pole erected on concrete or a roadbed, and is characterized by including a step of attaching a protective steel plate to the lower end of the steel pipe pole so that the lower end contacts the concrete or roadbed without chipping the concrete or roadbed.

[0014] In addition, in the repair method for an existing steel pipe pole according to the present invention, it is preferable that the protective steel plate is a single strip-shaped steel plate extending in the circumferential direction of the existing steel pipe pole.

[0015] In addition, in the method for repairing an existing steel pipe pole according to the present invention, it is preferable that both ends in the circumferential direction of the strip-shaped steel plate are formed into inclined surfaces facing each other.

[0016] Furthermore, in the method for repairing an existing steel pipe pole according to the present invention, it is preferable to include a step of attaching a water-stopping material to the lower end of the steel pipe pole before the step of attaching the protective steel plate.

[0017] Furthermore, in the method for repairing an existing steel pipe pole according to the present invention, it is preferable to include a step of bending and positioning the lower end of the water-stopping material along the concrete or roadbed.

[0018] Furthermore, in the repair method for an existing steel pipe pole according to the present invention, it is preferable that the water-stopping material is a single water-stopping sheet extending circumferentially around the steel pipe pole.

[0019] In addition, in the method for repairing an existing steel pipe pole according to the present invention, it is preferable that the water-stopping material is divided into multiple pieces in the circumferential direction of the steel pipe pole.

[0020] In addition, in the repair method for an existing steel pipe pole according to the present invention, it is preferable that the protective steel plate is a combination of divided steel plate pieces that are divided into a plurality of pieces in the circumferential direction of the steel pipe pole.

[0021] Furthermore, in the method for repairing an existing steel pipe pole according to the present invention, it is preferable to include a step of attaching an attachment band to the outer peripheral surface of the protective steel plate. [Effects of the Invention]

[0022] The method for repairing existing steel pipe poles according to the present invention includes a step of attaching a protective steel plate to the lower end of the steel pipe pole so that the lower end contacts the concrete or roadbed without chipping away at the concrete or roadbed. This eliminates the need to excavate the concrete at the ground level to expose the ground level of the steel pipe pole, reduces the curing period for the concrete, etc., and significantly shortens construction time. It also enables anyone to easily repair existing steel pipe poles without relying on the skills of a construction technician for painting, etc. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing a steel pipe pole after a repair method for an existing steel pipe pole according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram illustrating the process of installing a water-stop material in the repair method for an existing steel pipe pole according to an embodiment of the present invention. [Figure 3] FIG. 2 is a diagram illustrating details of the process of installing a water-stop material in the steel pipe pole repair method according to an embodiment of the present invention. [Figure 4] 1 is a diagram illustrating a process of attaching a protective steel plate in a repair method for an existing steel pipe pole according to an embodiment of the present invention. FIG. [Figure 5] 1A and 1B are diagrams illustrating a protective steel plate used in a steel pipe pole repair method according to an embodiment of the present invention, where (a) illustrates the case where a single steel plate is applied, and (b) illustrates the case where a divided steel plate piece is used. [Figure 6] FIG. 2 is an enlarged view of an end portion of a protective steel plate used in the steel pipe pole repair method according to the embodiment of the present invention. [Figure 7] 10A and 10B are diagrams illustrating the process of attaching a mounting band in the repair method for an existing steel pipe pole according to an embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing a modified example of a protective steel plate used in the steel pipe pole repair method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0025] FIG. 1 is a diagram showing a steel pipe pole after a method for repairing an existing steel pipe pole according to an embodiment of the present invention; FIG. 2 is a diagram illustrating the step of attaching a water-stop material in the method for repairing an existing steel pipe pole according to an embodiment of the present invention; FIG. 3 is a diagram illustrating details of the step of attaching a water-stop material in the method for repairing an existing steel pipe pole according to an embodiment of the present invention; FIG. 4 is a diagram illustrating the step of attaching a protective steel plate in the method for repairing an existing steel pipe pole according to an embodiment of the present invention; FIG. 5 is a diagram illustrating a protective steel plate used in the method for repairing a steel pipe pole according to an embodiment of the present invention, where (a) is a diagram illustrating the case where a single steel plate is applied, and (b) is a diagram illustrating the case where a divided steel plate piece is used; FIG. 6 is an enlarged view of the end of the protective steel plate used in the method for repairing a steel pipe pole according to an embodiment of the present invention; FIG. 7 is a diagram illustrating the step of attaching a mounting band in the method for repairing an existing steel pipe pole according to an embodiment of the present invention; and FIG. 8 is a diagram illustrating a modified example of the protective steel plate used in the method for repairing a steel pipe pole according to an embodiment of the present invention.

[0026] As shown in Fig. 1, a steel pipe pole 1 that has been subjected to the method for repairing an existing steel pipe pole according to this embodiment has its lower end repaired. The steel pipe pole 1 is erected on a road surface 2 equivalent to concrete or a roadbed. A water-stopping material 20 is attached to the lower end of the existing steel pipe pole 1 so as to cover the outer periphery of the steel pipe pole 1. A protective steel plate 10 is attached so as to cover the water-stopping material 20 and so that its lower end surface is in contact with the road surface 2. A mounting band 30 is attached and fixed to the outer periphery of the protective steel plate 10. The length of the water-stopping material 20 and the protective steel plate 10 is preferably about 0.2D to 2D of the steel pipe pole 1, and a length of about 0.5D is more preferable. Here, D is the diameter of the steel pipe pole 1.

[0027] The existing steel pipe pole 1 can be made of various conventionally known steel pipe poles, and it is preferable to use, for example, a general structural carbon steel pipe. Furthermore, the existing steel pipe pole 1 is not limited to the above-mentioned materials, and various conventionally known materials may be used. Furthermore, the existing steel pipe pole 1 is erected on a road surface 2 (not shown) made of concrete, mortar, or the like poured on the ground surface, and has a surface portion exposed above the ground edge of the road surface 2 and a buried portion buried within the road surface 2.

[0028] Next, a method for repairing an existing steel pipe pole according to this embodiment will be described. As shown in FIG. 2 , a water-stopping material 20 is attached to the lower end of an existing steel pipe pole 1 at a location where the lower end contacts the road surface 2. At this time, the water-stopping material 20 is attached so as to contact the road surface 2 without scraping the road surface 2. The water-stopping material 20 is wrapped around the entire circumferential direction of the lower end of the existing steel pipe pole 1, close to the ground. Various conventionally known water-stopping materials can be used as the water-stopping material 20, but a sheet material made of a water-impermeable material such as rubber, silicone, or clay is preferably used. By wrapping the water-stopping material 20 around the steel pipe pole 1 in this manner, the water-stopping material 20 has water- and oxygen-impermeable properties. Therefore, if the water-stopping material 20 is sufficiently adhered to the surface of the steel pipe pole 1, the steel pipe pole 1 will not rust.

[0029] 3, the lower end 21 of the water-stopping material 20 may be bent and positioned along the ground-level concrete portion of the road surface 2. By positioning the water-stopping material 20 bent in this manner, it is possible to prevent water from seeping in between the road surface 2 and the water-stopping material 20, thereby preventing corrosion of the existing steel pipe pole 1. The bent length of the water-stopping material 20 is preferably 10 mm or more.

[0030] The above-mentioned waterstop material 20 has been described as being a single sheet-like waterstop material wrapped around the ground at the lower end of the existing steel pipe pole 1, but multiple divided waterstop materials may also be arranged along the outer periphery of multiple existing steel pipe poles 1. In this case, it is preferable that adjacent divided waterstop materials are arranged so that the circumferential end sides overlap each other. Furthermore, the waterstop material 20 may be attached to the surface of the existing steel pipe pole 1 using an adhesive or the like, or may be fixed by being sandwiched between protective steel plates 10, which will be described later. Furthermore, the waterstop material 20 may be divided into multiple pieces in the circumferential direction, and it is preferable that the divided waterstop materials 20 be formed into a size that is easy to install.

[0031] Next, as shown in Fig. 4, a strip-shaped steel plate 11 is wrapped around and attached so as to cover the already attached water-stopping material 20. As shown in Fig. 5(a), the strip-shaped steel plate 11 is preferably made of a thin plate having a thickness of about 0.3 to 4.0 mm, and is preferably subjected to a galvanizing treatment or a coating on the galvanizing treatment as a corrosion prevention measure.

[0032] As shown in Fig. 5(b), the protective steel plate 10 may be composed of a plurality of divided steel plate pieces 12 in the circumferential direction. Furthermore, as shown in Fig. 6, the circumferential end edges of the strip-shaped steel plate 11 and the divided steel plate pieces 12 are formed with opposing inclined surfaces 13, and by matching the inclined surfaces 13, the protective steel plate 10 can be ensured to have a smooth circular shape even when combined so that both ends overlap, and the protective steel plate 10 can be attached tightly without any gap between the outer periphery of the steel pipe column 1 and the protective steel plate 10.

[0033] Next, as shown in Fig. 7, an attachment band 30 is attached to the outer periphery of the protective steel plate 10. The attachment band 30 restrains the protective steel plate 10 so as to bring the protective steel plate 10 into close contact with the outer periphery of the steel pipe pole 1, and various conventionally known bands can be used, but various attachment bands 30 such as galvanized or stainless steel can be applied depending on the repair method. Note that it is sufficient that one or more attachment bands 30 are attached to the outer periphery of the protective steel plate 10, and the number of attachment bands 30 can be increased appropriately depending on the size of the protective steel plate 10 and the diameter of the steel pipe pole 1.

[0034] After the mounting band 30 is attached, a waterproofing agent such as silicone may be applied circumferentially to the upper and lower ends of the protective steel plate 10. Furthermore, a similar waterproofing agent may be applied vertically to the overlapping portions of the protective steel plate 10 to provide waterproofing.

[0035] Furthermore, the repair method for an existing steel pipe pole according to this embodiment has been described in terms of a case in which a protective steel plate 10 consisting of a strip-shaped steel plate 11 or a divided steel plate piece 12 is restrained with an attachment band 30, but as shown in Figure 8, it is also possible to wrap a flange steel plate 14 having flanges 15 formed at the end thereof around the pole and join the flanges 15 together using conventional joining means such as bolts.

[0036] In this way, according to the repair method for existing steel pipe poles of this embodiment, the road surface does not need to be chipped, the curing period for backfilled concrete can be reduced, workability is greatly improved regardless of the skill of the contractor, and it can easily be done at night when there are restrictions on work time.

[0037] Furthermore, according to the repair method for an existing steel pipe pole according to this embodiment, the surface of the existing steel pipe pole is covered with the protective steel plate 10, which prevents the water-stopping material 20 from being damaged or peeling off. Furthermore, if corrosion or some other defect occurs in the protective steel plate 10, this can be easily addressed by replacing the protective steel plate 10, making it possible to easily perform re-repair without causing defects such as corrosion in the steel pipe pole 1 itself. Furthermore, since the surface of the existing steel pipe pole has irregularities, the water-stopping material 20 can fit into these irregularities, allowing the protective steel plate 10 to be attached without gaps.

[0038] In the above-described method for repairing an existing steel pipe pole according to this embodiment, the water-stopping material 20 is wrapped around the pole and then the protective steel plate 10 is attached. However, the water-stopping material 20 may be attached to the inner peripheral surface of the protective steel plate 10 in advance. In this case, the construction work can be further reduced, and construction costs can be easily reduced. Furthermore, although the description has been given of the case where the segmented steel plate pieces 12 are divided into three pieces in the circumferential direction, they may be divided into two pieces or four or more pieces. It is clear from the claims that such various modifications or improvements are also included within the technical scope of the present invention. [Explanation of symbols]

[0039] 1 steel pipe pole, 2 road surface, 10 protective steel plate, 11 steel strip, 12 divided steel plate piece, 13 slope, 14 flange steel plate, 15 flange, 20 water stop material, 21 bent portion, 30 mounting band.

Claims

1. A repair method for an existing steel pipe pole erected on concrete or a roadbed, A method for repairing an existing steel pipe pole, comprising the step of attaching a protective steel plate to the lower end of the steel pipe pole so that the lower end contacts the concrete or roadbed without chipping the concrete or roadbed.

2. The repair method for an existing steel pipe pole according to claim 1, A repair method for an existing steel pipe pole, characterized in that the protective steel plate is a single strip-shaped steel plate extending in the circumferential direction of the existing steel pipe pole.

3. The repair method for an existing steel pipe pole according to claim 2, A method for repairing an existing steel pipe pole, characterized in that both ends in the circumferential direction of the strip steel plate are formed into inclined surfaces facing each other.

4. The repair method for an existing steel pipe pole according to claim 1, A method for repairing an existing steel pipe pole, characterized in that it includes a step of attaching a water-stopping material to the lower end of the steel pipe pole before the step of attaching the protective steel plate.

5. The repair method for an existing steel pipe pole according to claim 4, A method for repairing an existing steel pipe pole, comprising a step of bending and positioning the lower end of the water-stopping material along the concrete or roadbed.

6. The repair method for an existing steel pipe pole according to claim 4, A method for repairing an existing steel pipe pole, characterized in that the water-stopping material is a single water-stopping sheet extending circumferentially around the steel pipe pole.

7. The repair method for an existing steel pipe pole according to claim 4, A method for repairing an existing steel pipe pole, characterized in that the water-stopping material is divided into multiple pieces circumferentially around the steel pipe pole.

8. The repair method for an existing steel pipe pole according to claim 1, A method for repairing an existing steel pipe pole, characterized in that the protective steel plate is a combination of divided steel plate pieces divided into a plurality of pieces in the circumferential direction of the steel pipe pole.

9. The repair method for an existing steel pipe pole according to claim 1, A repair method for an existing steel pipe pole, comprising a step of attaching an attachment band to the outer peripheral surface of the protective steel plate.

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