JP7303363B1 - Seismic reinforcement structure for electric pole and method for seismic reinforcement of electric pole - Google Patents

Abstract

An object of the present invention is to provide a seismic reinforcement structure for an electric utility pole and a method for seismic reinforcement of an electric utility pole, in which it is possible to easily confirm whether or not the electric pole needs to be replaced, and to improve workability. SOLUTION: An earthquake-resistant reinforcement structure 100 for an electric utility pole includes an existing electric pole EP, an upper steel pipe unit 11 forming a cylindrical body surrounding the outer periphery of the electric utility pole EP by joining a plurality of members having an arc shape when viewed in cross section, A lower steel pipe unit 13 which is spaced apart from the upper steel pipe unit 11 in the vertical direction and which is composed of a plurality of members having arcuate cross-sections joined to form a cylindrical body surrounding the electric pole EP, the upper steel pipe unit 11 and the lower steel pipe unit. The bars 14 are all provided on the outer peripheral surfaces of the upper steel pipe unit 11 and the lower steel pipe unit 13, and the electric pole EP is connected to the upper steel pipe unit 11 and the lower steel pipe unit 13. [Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to an earthquake-resistant reinforcement structure for an electric utility pole and an earthquake-resistant reinforcement method for an electric utility pole.

Conventionally, in response to the frequent damage caused by the collapse of electric utility poles during large-scale earthquakes, research has been conducted on reinforcement structures to reinforce the seismic resistance of existing electric utility poles.

As an example of a reinforcing structure that reinforces an existing electrified pole, Patent Document 1 discloses a technique of a reinforcing structure that uses a tubular reinforcing member that surrounds the outer periphery of an electrified pole.

JP 2017-110448 A

According to the column reinforcement structure disclosed in Patent Document 1, if a rod-shaped reinforcing member is fixed to the inner peripheral surface of a tubular reinforcing member provided to surround an electric pole, the rod-shaped reinforcing member is fixed. Although it is preferable because it is buried and covered by the first filler (see paragraph [0025] of the specification of Patent Document 1), an unexpected horizontal load is input due to a large earthquake or the like, and the rod-shaped reinforcing material becomes plastic. When deformation (for example, buckling deformation) occurs, it is not possible to visually confirm the presence or absence of plastic deformation of all the rod-shaped reinforcing members fixed to the inner peripheral surface from the appearance, so it is not possible to easily check whether the electric pole needs to be replaced. There is a problem with the point. Also, when installing a wire saw to cut the electric pole and divide it into upper and lower parts, the insertion position into the cylindrical reinforcing material and the removal from the cylindrical reinforcing material are determined so as to avoid the rod-shaped reinforcing material on the inner peripheral surface. (See paragraphs [0032]-[0035] of Patent Document 1 and FIGS. 7 to 10), but a sufficient distance can be secured between the insertion position and the removal position. However, there is a problem in that the frictional resistance from the electric pole increases in a part of the wire saw, and the electric pole cannot be completely cut.

Accordingly, the present invention has been devised in view of the above-described problems, and its object is to enable easy confirmation of whether or not an electric pole needs to be replaced, and to improve workability. To provide an earthquake-resistant reinforcement structure for an electric utility pole and an earthquake-resistant reinforcement method for an electric utility pole.

The seismic reinforcement structure for an electric utility pole in the first invention is a seismic reinforcement structure for an electric utility pole in which a steel pipe unit is installed on the outer circumference of an existing electric pole, and the existing electric pole and a plurality of members having an arc shape in cross section are joined together. and an upper steel pipe unit forming a cylindrical body surrounding the outer circumference of the electric pole, and a plurality of members spaced apart from the upper steel pipe unit in the vertical direction and having an arc shape in cross section are joined to surround the outer circumference of the electric pole. a lower steel pipe unit forming a cylindrical body; and a plurality of bars vertically connecting the upper steel pipe unit and the lower steel pipe unit, wherein all of the bars are connected to the upper steel pipe unit and the lower steel pipe unit. and the electrified pole is separated between the upper steel pipe unit and the lower steel pipe unit.

A seismic reinforcement structure for an electric utility pole according to the second invention is characterized in that, in the first invention, a gap between the electric utility pole, the upper steel pipe unit, and the lower steel pipe unit is filled with a first filler. .

The seismic reinforcement structure for an electric pole according to the third invention is characterized in that, in the first invention or the second invention, the bar is attached to the outer circumferences of the upper steel pipe unit and the lower steel pipe unit via a gap holding part that holds a predetermined gap. characterized by being provided in

A method for seismic reinforcement of an electric pole according to the fourth invention is a method for seismic reinforcement of an electric pole by installing a steel pipe unit on the outer circumference of an existing electric pole. a steel pipe unit forming step of joining a plurality of arc-shaped members to form an upper steel pipe unit and a lower steel pipe unit spaced apart in the vertical direction on the outer periphery of an existing electric pole; and a dividing step of vertically dividing the electric pole between the upper steel pipe unit and the lower steel pipe unit.

According to the first to fourth inventions, the electrified pole is divided between the upper steel pipe unit and the lower steel pipe unit, which are reinforced with the steel pipe units and joined with the bars. For this reason, a plastic hinge is formed between the upper steel pipe unit and the lower steel pipe unit, and the energy due to the vibration applied to the electric pole is easily absorbed by the plastic deformation of the bar. In addition, since all the bars are exposed to the outside, the presence or absence of plastic deformation of all the bars can be easily visually confirmed. As a result, it is possible to easily determine whether or not the electric pole needs to be replaced.

Further, according to the first to fourth inventions, a plurality of bars for vertically connecting the upper steel pipe unit and the lower steel pipe unit are provided, and all the bars are provided on the outer peripheral surfaces of the upper steel pipe unit and the lower steel pipe unit. be done. That is, compared to the case where the bar is provided on the inner peripheral surface, it is easier to secure a wider interval for taking out the wire saw used for dividing the electric pole. Therefore, it is possible to avoid an increase in frictional resistance in a part of the wire saw and reduce the risk that the electric pole cannot be cut. Thereby, the improvement of workability can be aimed at.

In particular, according to the second aspect of the invention, the gap between the electrified pole and the upper steel pipe unit and the lower steel pipe unit is filled with the first filler. For this reason, it becomes easy to transmit the energy due to the vibration applied to the electric pole to each bar via the first filler and the steel pipe unit. This makes it possible to more reliably absorb seismic energy and prevent brittle fracture of the utility pole.

In particular, according to the third invention, the bar material is provided on the outer circumference of the steel pipe unit via the gap holding portion. That is, the bar is further separated from the electrified pole by the indirect support. Therefore, when the bar is plastically deformed, it is possible to further prevent the bar from coming into contact with the utility pole or the steel pipe unit and impairing the energy absorption performance. This makes it possible to more reliably absorb seismic energy and prevent brittle fracture of the utility pole.

FIG. 1 is a perspective view schematically showing an outline of a utility pole seismic reinforcement work for an existing utility pole and a seismic reinforcement structure of the utility pole reinforced with a steel pipe unit. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 showing the upper seismic reinforcement structure and the lower seismic reinforcement structure. FIG. 3 is a cross-sectional view taken along the line BB in FIG. 1, showing the dividing position of the middle-stage earthquake-resistant reinforcement structure. FIG. 4 shows the first reinforcing member of the steel pipe unit, where (a) is a plan view and (b) is a side view. FIG. 5 shows the second reinforcing member of the steel pipe unit, where (a) is a plan view and (b) is a side view. 6A and 6B are diagrams showing the division position of the middle seismic reinforcement structure before the division process is performed, where (a) is a cross-sectional view of the present invention and (b) is a cross-sectional view of a comparative example. 7A and 7B are diagrams showing the division position of the middle seismic reinforcement structure during the division process, where (a) is a cross-sectional view of the present invention and (b) is a cross-sectional view of a comparative example.

Hereinafter, an example of an earthquake-resistant reinforcement structure for an electric pole as an embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that the configuration in each figure is schematically described for explanation, and for example, the size of each configuration and the comparison of sizes for each configuration may be different from those in the drawings.

(Electrical pole earthquake-resistant reinforcement structure 100)
The seismic reinforcement structure 100 for electric poles will be described with reference to the drawings. The earthquake-resistant reinforcement structure 100 for electric poles includes an upper stage earthquake-resistant reinforcement structure and a lower stage earthquake-resistant reinforcement structure. The electrification pole earthquake-resistant reinforcement structure 100 may further include a middle-stage earthquake-resistant reinforcement structure between the upper-stage earthquake-resistant reinforcement structure and the lower-stage earthquake-resistant reinforcement structure. FIG. 1 is a schematic perspective view of a seismic reinforcement work for an existing electric pole EP and a seismic reinforcement structure 100 reinforced with a steel pipe unit 10. FIG. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 showing an example of an upper seismic reinforcement structure and a lower seismic reinforcement structure of the seismic reinforcement structure 100. As shown in FIG. FIG. 3 is a cross-sectional view taken along line BB of FIG.

For example, as shown in FIG. 1, the seismic reinforcement work for the electric utility pole EP consists of an upper steel pipe unit 11 and a lower steel pipe unit 13 separated vertically from the upper steel pipe unit 11 on the outer periphery of the existing electric power pole EP. The steel pipe units 10 are installed to construct the seismic reinforcing structure 100 . Here, the upper steel pipe unit 11 constitutes a part of the upper seismic reinforcement structure, and the lower steel pipe unit 13 constitutes a part of the lower seismic reinforcement structure.

In the present embodiment, the earthquake-resistant reinforcement structure 100 for the electric pole is made thinner than the upper steel pipe unit 11 and the lower steel pipe unit 13, so that the middle steel pipe unit 12 is adjusted to have a lower strength. Although an example having the constructed middle stage earthquake-resistant reinforcement structure will be described, the structure is not limited to this as long as the structure functions as a plastic hinge portion between the upper steel pipe unit 11 and the lower steel pipe unit 13 . For example, instead of the middle steel pipe unit 13, the middle stage anti-seismic reinforcement structure may be composed of a protective sheet material or the like having a lower strength than the steel material, or the installation thereof may be omitted.

The electric pole EP is assumed to be a PC electric pole with a diameter of 400 mm, for example. Conventional PC electric poles are reinforced with PC steel wires PC1 installed inside them. There is a risk that the electric pole EP will exhibit a brittle fracture mode. For this reason, in the utility pole seismic reinforcement work according to the present invention, as will be described later, the outer periphery of the utility pole EP is surrounded by a steel pipe unit 10 having an upper steel pipe unit 11 and a lower steel pipe unit having a plurality of bars 14 all joined to the outer peripheral surface. , and then cut the electric pole EP together with the embedded PC steel wire PC1 at a position between the upper steel pipe unit 11 and the lower steel pipe unit 13 with a wire saw.

In addition, in the electric pole earthquake-resistant reinforcement structure 100, for example, the gap between the electric pole EP and the steel pipe unit 10 is filled with the first filler M1. In addition, the electrification pole earthquake-resistant reinforcement structure 100 is configured such that the second filler material is injected into the inner cavity EPa through an injection hole IN communicating with the inner cavity EPa and a discharge confirmation hole OUT, which are drilled in, for example, a hollow electrification pole EP. M2 is injection filled. In addition, in the electric pole earthquake-resistant reinforcement structure 100, for example, the third filler M3 is injected and filled into the gap generated by the division of the PC steel wire PC1 and the electric pole EP (see FIG. 3). As a result, the earthquake-resistant reinforcement structure 100 of the utility pole absorbs input energy during a large earthquake and prevents brittle fracture by plastically deforming the rods 14 provided on the outer periphery of the steel pipe unit 10 . Here, non-shrinkage mortar, for example, is used as the first filler M1 and the second filler M2. As the third filler M3, a stuffing material capable of bearing the vertical compressive force of the divided electric pole EP is used, for example, a known synthetic resin, non-shrink cement milk, or the like is used.

<Steel pipe unit 10>
The steel pipe unit 10 is made of a steel such as a general structural rolled steel plate (SS400) that has been subjected to rust prevention treatment such as hot dip galvanization. The steel pipe unit 10 includes, for example, an upper steel pipe unit 11 and a lower steel pipe unit 13, as shown in FIG. Bars 14 made of a plurality of reinforcing bars are welded to the outer peripheral surfaces of the upper steel pipe unit 11 and the lower steel pipe unit 13, and the bars 14 are prevented from separating from the respective steel pipe plates when seismic energy is absorbed. A protective steel member 15 is also attached for prevention. The upper steel pipe unit 11 and the lower steel pipe unit 13 are separated vertically, and between the upper steel pipe unit 11 and the lower steel pipe unit 13, for example, the middle steel pipe unit 12 to which the bar 14 is not attached is provided. (See FIGS. 1 and 3).

The upper steel pipe unit 11 and the lower steel pipe unit 13 are a vertically symmetrical pair of members connected by a plurality of (eight in the illustrated embodiment) bars 14 . Therefore, hereinafter, the lower steel pipe unit 13 will be described only by the reference numerals, and the upper steel pipe unit 11 will be substituted for the lower steel pipe unit 13, and detailed description will be omitted.

<Upper Steel Pipe Unit 11, Lower Steel Pipe Unit 13>
The upper steel pipe unit 11 (lower steel pipe unit 13), for example, as shown in FIG. is divided into

The first reinforcing member 11a (13a) is made of a steel material such as a general structural rolled steel plate (SS400) having a thickness of 9 mm, for example, as shown in FIG. It is a member whose base is a bent cylindrical body 110 (130).

As shown in FIG. 4B, for example, the cylindrical body 110 has lifting holes h1 along the edge of the upper end (five places in FIG. 4). The lifting hole h1 is a hole for inserting a shackle or the like used for hooking a hook bolt for lifting the cylindrical body 110 to the mounting position of the electric pole EP. The lifting hole h1 is, for example, a hole with a diameter of 10 mm.

A plurality of bolt holes 112 (132) are drilled in the cylindrical body 110 (130), as shown in FIG. 4(b), for example. The plurality of bolt holes 112 (132) are holes for bolting the tubular body 110 (130) and the tubular body 111 (131) of the second reinforcing member 11b (13b). A nut 113 is welded to the inner peripheral surface of the cylindrical body 110 inside the bolt hole 112 to be screwed with an M20 bolt. For this reason, the upper steel pipe unit 11 (lower steel pipe unit 13) can be assembled by simply screwing an M20 bolt into the bolt hole 115 from the outside of the cylindrical body 111 of the second reinforcing member 11b (13b), which will be described later. (13b) and the first reinforcing member 11a (13a) can be easily joined in a short time.

The cylindrical body 110 (130) is, for example, as shown in FIG. A spacer 114 (134) may protrude to secure a gap S1 for filling the material M1. The spacer 114 (134) consists of a steel flat bar with a height of 10 mm and a thickness of 16 mm, for example.

In the upper steel pipe unit 11 (lower steel pipe unit 13), for example, the gap S1 between the electric pole EP is filled with the first filler M1. In this case, it becomes easier to transmit energy due to vibration applied to the electric pole EP to each bar 14 via the first filler M1 and the steel pipe unit 10 . As a result, it is possible to more reliably absorb seismic energy and prevent brittle fracture of the utility pole EP.

Further, at this time, as shown in FIG. 1, for example, the internal cavity EPa of the electric pole EP may be filled with the second filler M2 up to a position above the first filler M1. In this case, when the third filler M3 is injected and filled into the gap created by the division of the electric pole EP, the internal cavity EPa below the division position is already filled with the second filler M2. It is possible to prevent the third filler M3 from falling into the EPa and efficiently fill the third filler M3.

On the other hand, as shown in FIG. 5A, the second reinforcing member 11b (13b) is made of a steel material such as a general structural rolled steel plate (SS400) having a thickness of 9 mm and having an inner peripheral surface with a radius of curvature of 254 mm. It is a member whose base is a tubular body 111 (131) bent into an arc shape.

Like the tubular body 110, the tubular body 111 is provided with lifting holes h1 (three in FIG. 5) along the edge of the upper end, as shown in FIG. 5B, for example.

A plurality of bolt holes 115 (135), for example, are formed in the cylindrical body 111 (131). The plurality of bolt holes 115 (135) are holes for bolting the tubular body 111 (131) and the tubular body 110 (130) of the first reinforcing member 11a (13a).

The cylindrical body 111 and the cylindrical body 131 are joined via a bar 14 provided in advance on the outer periphery.

<Middle seismic reinforcement structure>
The middle seismic reinforcing structure refers to a structure between the upper steel pipe unit 11 and the lower steel pipe unit 13 .

In the middle seismic reinforcing structure, the electrification pole EP is divided at the position of at least one of the slits 126 shown in FIG. 1, for example, as the division position. This dividing position functions as a plastic hinge portion of the electric pole EP. That is, the earthquake-resistant reinforcing structure 100 for electric poles includes a plurality of bars 14 that vertically connect the upper steel pipe unit 11 and the lower steel pipe unit 13, as will be described later. It is provided on the outer peripheral surface of the steel pipe unit 13 . Moreover, the electric pole EP is reinforced with steel pipe units 10 and vertically divided between an upper steel pipe unit 11 and a lower steel pipe unit 13 . In this case, a plastic hinge is formed between the upper steel pipe unit 11 and the lower steel pipe unit 13, and energy due to vibration applied to the electric pole EP is easily absorbed by plastic deformation. In addition, the presence or absence of plastic deformation of all the bars 14 exposed to the outside can be easily visually confirmed. This makes it possible to easily determine whether or not the electric pole EP needs to be replaced.

For example, as shown in FIG. 3, the middle stage earthquake-resistant reinforcement structure is composed of a middle stage steel pipe unit 12, a first filler M1, a third filler M3, and a bar 14. As shown in FIG. The middle steel pipe unit 12 is composed of two parts, for example, a first reinforcing member 12a having an arc-shaped cross section similar to the first reinforcing member 11a and a second reinforcing member 12b having an arc-shaped cross section similar to the second reinforcing member 11b. split.

The first reinforcing member 12a is formed by bending a steel material such as a rolled steel plate for general structure (SS400) having a thickness of 4.5 mm into a cylindrical body 120 having an inner peripheral surface with a radius of curvature of 245 mm and an arc cross section as a base. It is a member that Since the first reinforcing member 12a is thinner than the first reinforcing member 11a (13a), it is more likely to be plastically deformed than the first reinforcing member 11a (13a).

A plurality of bolt holes 122 are bored in the cylindrical body 120, as shown in FIG. 4B, for example. The plurality of bolt holes 122 are holes for bolting the tubular body 120 and the tubular body 121 of the second reinforcing member 12b. Also, on the inner peripheral surface of the tubular body 120 inside the bolt hole 122, a nut to be screwed with an M20 bolt is welded, similarly to the first reinforcing member 11a constituting the upper steel pipe unit 11. . Therefore, in the middle steel pipe unit 12, the second reinforcing member 12b and the first reinforcing member 12a can be joined simply by screwing an M20 bolt into the bolt hole 125 from the outside of the cylindrical body 121 of the second reinforcing member 12b, which will be described later. It can be done easily in a short time.

In the middle steel pipe unit 12, for example, the gap S1 between the electric pole EP is filled with the first filler M1. Further, the third filler M3 is filled up to the slit 126 in the gap generated by the division of the electric pole EP (see FIG. 3). The electric pole EP is cut together with the PC steel wire PC1 and the first filler M1, for example, by a wire saw inserted through a gap S2 shaped to cover the outer periphery of the electric pole EP.

On the other hand, the second reinforcing member 12b is a cylindrical body 121 that is formed by bending a steel material such as a rolled steel plate for general structure (SS400) having a thickness of 4.5 mm into an arcuate cross-sectional shape having an inner peripheral surface with a radius of curvature of 254 mm. It is a member used as a base. Since the second reinforcing member 12b is thinner than the first reinforcing member 11b (13b), it is more likely to be plastically deformed than the second reinforcing member 11b (13b).

A plurality of bolt holes 125 are bored in the cylindrical body 121, as shown in FIG. 5B, for example. The plurality of bolt holes 125 are holes for bolting the tubular body 121 and the tubular body 120 of the first reinforcing member 12a.

The cylindrical body 121 is provided with a slit 126 for inserting a jig for dividing the electric pole EP in the middle steel pipe unit 12, for example, at the dividing position. In this embodiment, an example in which two slits 126 are provided separately in the vertical direction is shown, but the division of the electric pole EP may be performed at least at the position of one of the slits 126, and the other slit 126 may be divided. 126 is provided as a preliminary in case the electric pole EP cannot be cut in one slit 126 .

In this embodiment, a tubular body 120 is provided between the tubular body 110 and the tubular body 130 as the first reinforcing member 12a, and a second reinforcing member 120 is provided between the tubular body 111 and the tubular body 131. Although an example in which the cylindrical body 121 is provided as the second reinforcing member 12b has been shown, the cylindrical body 120 and the cylindrical body 121 may not be provided when the installation of the middle seismic reinforcement structure is omitted.

<Bar 14>
The bars 14 are all provided on the outer peripheral surfaces of the upper steel pipe unit 11 and the lower steel pipe unit 13 so as to vertically connect the upper steel pipe unit 11 and the lower steel pipe unit 13 . The bar 14 is a reinforcing bar made of a deformed steel bar of D25 (SD390), for example. The bar 14 has a total length of 900 mm, for example, and both longitudinal end portions within a range of 200 mm from the upper and lower ends thereof are welded to the cylindrical bodies 110 and 130 . The bar 14 has an intermediate portion that is not fixed and is free, and the free section undergoes plastic deformation during an earthquake and absorbs the energy input to the earthquake-resistant reinforcement structure 100 of the utility pole. The bar 14 is plastically deformed when an external force is applied due to an earthquake or the like. In this case, when the bar 14 is plastically deformed, it is possible to prevent the energy absorption performance from being hindered due to contact with the utility pole EP, the steel pipe unit 10, the first filler M1, and the like. As a result, it is possible to reliably absorb the seismic energy and prevent brittle fracture of the electric pole EP.

As shown in FIG. 4(a), for example, the bar 14 connects the cylindrical bodies 110 and 130 in the vertical direction via a gap holding portion 14a that holds a predetermined gap. It is provided on the outer peripheral surfaces of 110 and 130 . The gap holding portion 14a is, for example, a spacer with a thickness of 4.5 mm and a length of 200 mm. The gap retainer 14a is slightly lifted from the outer peripheral surface of each cylindrical body 110, 130, and is firmly fixed together with the gap retainer 14a by K-shaped flare welding in a range of 200 mm from the end portion. 110 and 130 are integrated. That is, the bar 14 is further separated from the electric pole EP by the indirect support 14a. In this case, when the bar 14 is plastically deformed, it is possible to further prevent the energy absorption performance from being hindered due to contact with the utility pole EP, the steel pipe unit 10, the first filler M1, and the like. As a result, it is possible to more reliably absorb seismic energy and prevent brittle fracture of the utility pole EP. Note that the gap holding portion 14a is similarly provided for each of the cylindrical bodies 111 and 131, as shown in FIG. 5(a), for example.

(Construction method of earthquake-resistant reinforcement structure 100 for electric pole)
Next, a method for constructing the earthquake-resistant reinforcement structure 100 for an electric utility pole (an earthquake-resistant reinforcement method for an electric utility pole EP) according to the embodiment of the present invention will be described. A seismic reinforcement method for an electric pole EP includes a steel pipe unit forming step and a dividing step.

<Advance preparation>
As a preparatory work for carrying out the construction method of the utility pole seismic reinforcement work according to the embodiment of the present invention, the type of the foundation on which the existing electric pole EP that is the target of the seismic reinforcement work is erected and the presence or absence of obstacles are confirmed in advance. do. Of course, if there are attachments or the like that interfere with construction, remove those that can be removed before construction. Further, in the steel pipe unit forming step described later, a hole is drilled to fill the internal cavity EPa with the second filler M2. Specifically, for example, as shown in FIG. 1, an injection hole IN and a discharge confirmation hole OUT are drilled at a predetermined height of the electric pole EP from the outer peripheral surface of the electric pole EP to communicate with the internal cavity EPa. The discharge confirmation hole is provided, for example, at a position above the upper end of the upper steel pipe unit 11 by 1D (the diameter of the outer peripheral cross section of the electrification pole EP). The second filling material M2 may be filled in the internal cavity EPa in advance, or may be filled after filling the first filling material M1, which will be described later, before the electric pole EP is divided.

In addition, a wire saw pipe 21 having a gap S2 inside for inserting a wire saw used as a cutting jig is installed at a position (position of the slit 126 in FIG. 1) for dividing the electric pole EP. Temporarily placed by wrapping it around in advance. The wire saw pipe 21 is made of a material having enough strength to be cut by a wire saw, and is made of synthetic resin (plastic), for example.

The first reinforcement member 11a of the upper steel pipe unit 11 and the first reinforcement member 13a of the lower steel pipe unit 13 are, for example, as shown in FIG. joined and integrated. In order to reduce the number of times the reinforcing member is lifted, the first reinforcing member 12a of the middle steel pipe unit 12 may be temporarily fixed with an adhesive tape or the like between the first reinforcing members 11a and 13a. However, the first reinforcing member 12a is not integrated with the reinforcing members 11a and 13a in order to function as plastic hinges between the reinforcing members 11a and 12a and between the reinforcing members 12a and 13a. The second reinforcing member 11b of the upper steel pipe unit 11 and the second reinforcing member 13b of the lower steel pipe unit 13 are, for example, as shown in FIG. pre-bonded and integrated with the Also, similarly to the first reinforcing member 12a, the second reinforcing member 12b of the middle steel pipe unit 12 may be temporarily fixed between the second reinforcing members 11b and 13b with an adhesive tape or the like. The member 12b is not integrated with each reinforcing member 11b, 13b.

<Steel pipe unit formation process>
In the steel pipe unit forming step, the steel pipe unit 10 is constructed so as to have a predetermined positional relationship with the electric pole EP to be reinforced. Specifically, the upper steel pipe unit 11 and the lower steel pipe unit 13 are installed on the outer periphery of the electric pole EP. In this embodiment, each member of the middle steel pipe unit 12 temporarily fixed to each member of the upper steel pipe unit 11 and the lower steel pipe unit 13 is used to install the upper steel pipe unit 11 and the lower steel pipe unit 13. Although an example in which the steel pipe unit 12 is also constructed has been shown, each member of the steel pipe units 11 and 13 and each member of the middle steel pipe unit 12 that are independent of each member of the steel pipe units 11 and 13 are used to construct the interrupted steel pipe unit before and after the installation of each of the steel pipe units 11 and 13. 12 may be constructed separately.

First, each first reinforcing member 11a, 12a, 13a is lifted along the electric pole EP. Specifically, for example, a hook bolt provided on a hanger member preliminarily fixed to the electric pole EP and a shackle inserted through the lifting hole h1 are connected and lifted. When lifting, the distance between the hanger member and each first reinforcing member 11a, 12a, 13a is adjusted using another length adjusting jig such as a chain block without adjusting the length with the hook bolt. good too.

Similarly, each second reinforcing member 11b, 12b, 13b is also installed. At this time, each of the second reinforcing members 11b, 12b, 13b or the temporary wire saw is arranged so that the slit 126 provided in the second reinforcing member 12b is positioned at the position of the wire saw pipe 21 temporarily arranged by winding it around the outer periphery of the electric pole EP. The height of the arranged wire saw pipe 21 is adjusted. After that, the second reinforcing members 11b, 12b, 13b and the first reinforcing members 11a, 12a, 13a are bolted to construct the upper steel pipe unit 11, the middle steel pipe unit 12, and the lower steel pipe unit 13.

After installing the respective steel pipe units 11, 12, 13, for example, as shown in FIG. 21 are taken out and exposed to the outside of the middle steel pipe unit 12, the curing tape 22 is adhered to the slit 126 to fix the wire saw pipe 21.例文帳に追加At this time, the wire saw pipe 21 is arranged so as to form a gap S2 shown in FIG. In order to prevent the bar 14 from being accidentally cut by the wire saw, the wire saw pipe 21 needs to be taken out from two points that do not straddle the bar 14 . That is, both ends of the slit 126 are provided at positions not straddling the bar 14 .

After fixing the wire saw pipe 21 with the curing tape 22, the first filler M1 is injected into the gap S1 in each of the steel pipe units 11, 12, and 13 from the top of the upper steel pipe unit 11, and the first filler M1 is injected to the top of the upper steel pipe unit 11. Fill with the first filler M1. At this time, the first filler M1 does not enter the gap S2 in the wire saw pipe 21, and the gap S2 is maintained in the middle steel pipe unit 12.

Installation of the steel pipe unit 10 is completed as described above.

When the spacer 114 (134) is provided on the first reinforcing member 11a (13a), the spacer 114 (134), for example, as shown in FIG. and the electrification pole EP. Although not shown, the above-described hanger member may be used to support part of the upper steel pipe unit 11 so that the gap S1 is constant.

When injecting the first filler M1, as shown in FIG. 1, between the lower end of the steel pipe unit 10 and the base of the existing electric pole EP, the lower ends of the cylindrical bodies 130, 131 of the lower steel pipe unit 13 are placed between the lower end of the steel pipe unit 10 and the base of the existing electric pole EP. It is preferable to interpose a rubber material 5 having a U-shaped cross section and having a groove for inserting the . In this case, it is possible to prevent the first filler M1 filled in the steel pipe unit 10 from leaking out from the lower end. The rubber material 5 refers to a rubber elastic body having a characteristic (elastic deformation) that it expands and contracts greatly in the direction of applied force and returns to its original shape when the force is removed.

<Dividing process>
In the dividing step, the electric pole EP is vertically divided between the upper steel pipe unit 11 and the lower steel pipe unit 13 after the steel pipe unit 10 is installed in the steel pipe unit forming step. As a cutting method, an example of cutting using a known wire saw will be described.

When the gap S1 is filled with the first filler M1 in the previous step, it is confirmed that the compressive strength of the first filler M1 reaches a strength of 24 N/mm ^{2 or} more. After that, as shown in FIG. 6A, for example, the wire saw 23 is inserted into the gap S2 in the wire saw pipe 21 included in the middle steel pipe unit 12, and the wire saw 23 is installed between the main pulley 24 and the auxiliary pulley 25. do. Thereafter, after confirming that the wire saw is not in contact with the bar 14, the wire saw is rotated, and the electric pole EP, the PC steel wire PC1, the first filler M1, and the second filler M2 are removed together with the wire saw pipe 21. disconnect.

In addition, in the earthquake-resistant reinforcement structure 100 for an electric utility pole according to the present invention, since the bar 14 is provided on the outer peripheral side of the steel pipe unit 10, for example, as shown in FIG. Compared to the case where the members 14' are provided, the intervals between the bars 14 are increased, and the wire saw 23 can be easily arranged so that the radius of rotation thereof is increased. Further, when the wire saw 23 has a large radius of rotation, even if the wire saw 23 moves in the cutting direction indicated by the arrow, for example, as shown in FIG. It is difficult to completely cut off the pillar EP. On the other hand, when the radius of rotation of the wire saw 23 is small, for example, as shown in FIG. ), the frictional resistance that the wire saw 23 receives from the electric pole EP increases, and there is a risk that the electric pole EP cannot be completely cut. That is, since the bar 14 is provided on the outer periphery of the steel pipe unit 10, it is easier to secure a wider interval for taking out the wire saw 23 compared to the case where it is provided on the inner periphery of the steel pipe unit 10. It is possible to avoid an increase in frictional resistance from the pole EP and reduce the risk of not being able to completely cut the electric pole EP. Thereby, the improvement of workability can be aimed at.

After the electrification pole EP is divided, the gaps generated by the division are filled with a third filler M3 as shown in FIG. 3, for example. Specifically, after collecting the dust in the gap generated by the division, an injection pipe, an air release pipe, etc. are installed in the gap, and the third filler M3 is injected and filled using an electric dispenser or the like. .

This completes the installation of the earthquake-resistant reinforcement structure 100 for the electric pole.

According to this embodiment, the electric pole EP is reinforced with the steel pipe unit 10 and divided between the upper steel pipe unit 11 and the lower steel pipe unit 13 to which the bar 14 is joined. Therefore, a plastic hinge is formed between the upper steel pipe unit 11 and the lower steel pipe unit, and the energy due to the vibration applied to the electric pole EP is easily absorbed by the plastic deformation of the bar 14 . In addition, all the rods 14 are exposed to the outside, and the presence or absence of plastic deformation of all the rods 14 can be easily visually recognized. This makes it possible to easily determine whether or not the electric pole EP needs to be replaced.

Further, according to the present embodiment, a plurality of bars 14 are provided for vertically connecting the upper steel pipe unit 11 and the lower steel pipe unit 13, and all the bars 14 are connected to the outer peripheral surfaces of the upper steel pipe unit 11 and the lower steel pipe unit 13. provided in That is, compared to the case where the bar 14 is provided on the inner peripheral surface, it is easier to secure a wider interval for taking out the wire saw 23 used for dividing the electric pole EP. Therefore, it is possible to avoid an increase in frictional resistance in a part of the wire saw 23 and reduce the risk that the electric pole EP cannot be separated. Thereby, the improvement of workability can be aimed at.

Further, according to the present embodiment, the gaps between the electric pole EP and the upper steel pipe unit 11 and the lower steel pipe unit 13 are filled with the first filler M1. Therefore, it becomes easier to transmit energy due to vibration applied to the electric pole EP to each bar 14 via the first filler M1 and the steel pipe unit 10 . As a result, it is possible to more reliably absorb seismic energy and prevent brittle fracture of the utility pole EP.

Further, according to the present embodiment, the bar 14 is provided on the outer circumference of the steel pipe unit 10 via the gap holding portion 14a. That is, the bar 14 is further separated from the electric pole EP by the indirect support 14a. Therefore, when the bar 14 is plastically deformed, it can be prevented from contacting the utility pole EP and the steel pipe unit 10 and hindering the energy absorption performance. As a result, it is possible to more reliably absorb seismic energy and prevent brittle fracture of the utility pole EP.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

For example, in the middle seismic reinforcement structure, the middle steel pipe unit 12 may be used as a temporary unit when filling the first filler M1, and the middle steel pipe unit 12 may be removed in the seismic reinforcement structure when construction is completed. In addition, the middle seismic reinforcement structure may be replaced with a material other than steel, such as a sheet for temporary fixing, as long as it has sufficient strength to support the first filler M1 until the first filler M1 hardens.

100: Seismic reinforcement structure 10: Plural steel pipe units 11: Upper steel pipe unit h1: Lifting holes 11a, 12a, 13a: First reinforcing members 11b, 12b, 13b: Second reinforcing members 110, 111, 120, 121, 130, 131: Cylindrical bodies 112, 122, 132: Bolt holes 113: Nuts 114, 134: Spacers 115, 125, 135: Bolt holes 12: Middle steel pipe unit 126: Slit 13: Lower steel pipe unit 14: Bar 14a: Gap retention Body 15: Protective steel material 21: Wire saw pipe 22: Curing tape 23: Wire saw 24: Main pulley 25: Auxiliary pulley 5: Rubber material EP: PC electric pole EPa: Internal cavity PC1: PC steel wire S1: Gap S2: Gap IN : Injection hole OUT: Discharge confirmation hole M1: First filler M2: Second filler M3: Third filler

Claims (4)

An earthquake-resistant reinforcement structure for an electric pole in which a steel pipe unit is installed on the outer circumference of an existing electric pole,
existing electric poles,
an upper steel pipe unit configured by joining a plurality of members having an arc shape in cross section to form a cylindrical body surrounding the outer periphery of the electric pole;
a lower steel pipe unit vertically spaced apart from the upper steel pipe unit and configured by joining a plurality of members having an arc shape in cross section to form a cylindrical body surrounding the outer periphery of the electric pole;
a plurality of bars vertically connecting the upper steel pipe unit and the lower steel pipe unit;
with
All of the bars are provided on the outer peripheral surfaces of the upper steel pipe unit and the lower steel pipe unit,
An earthquake-resistant reinforcement structure for an electric pole, wherein the electric pole is divided between the upper steel pipe unit and the lower steel pipe unit. The seismic reinforcement structure for an electric pole according to claim 1, wherein a gap between the electric pole and the upper steel pipe unit and the lower steel pipe unit is filled with a first filler. The seismic reinforcement of the electric pole according to claim 1 or 2, wherein the bars are provided on the outer peripheries of the upper steel pipe unit and the lower steel pipe unit via a gap holding part that holds a predetermined gap. structure. A method for seismically reinforcing an electric pole by installing a steel pipe unit on the outer circumference of an existing electric pole,
An upper steel pipe unit and a lower steel pipe unit are formed on the outer periphery of an existing electrified pole by joining a plurality of members that are arcuate in cross section and have a plurality of vertically extending bars all joined to the outer periphery. a steel pipe unit forming step;
and a dividing step of vertically dividing the electric utility pole between the upper steel pipe unit and the lower steel pipe unit formed in the steel pipe unit forming step.

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