JP2011021377A - Construction method for heightening steel tower and temporary metallic arm used in the construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method for heightening a steel tower for shortening a period of power stoppage to suppress obstacles in electric power supply during heightening construction work to the minimum and returning from the power stoppage quickly in a short time from the viewpoint of stable electric power supply, and to provide a temporary metallic arm used in this construction method. <P>SOLUTION: In this construction method, supply of electric power to right and left circuits 16R, 16L of an existing steel tower 1 is alternately stopped, members 50, 51R, 51L, 52R, 52L being the temporary metallic arms 49 are attached to an inner side of the existing steel tower body provided with upper-phase wires 13R, 13L, ground electric wires 9R, 9L and the upper- phase wires 13R, 13L are moved to the temporary metallic arms, a top part of the existing steel tower body 1 supporting existing metallic arms and existing metallic arms 5R, 5L, 6R, 6L are cut and removed, a new tower body 17 is assembled on the top part of the existing steel tower body being cut and removed, supply of electric power to the right and left circuits is alternately stopped, new metallic arms 18R, 18L, 19R, 19L are attached to the new tower body, the ground electric wires and the upper-phase wires are moved to the new metallic arms, and the temporary metallic arms are removed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a steel tower raising method for further increasing the ground height of an overhead electric wire (power transmission line / distribution line) installed between a plurality of existing steel towers, and a temporary arm used for the method.

  In recent urban suburbs, new extensions and rebuilding of buildings such as houses are performed directly under and around existing overhead cables (transmission lines and distribution lines) (hereinafter also simply referred to as “wires”). In some cases, the separation distance between the existing electric wire and the building is insufficient. Also, in the suburbs of cities, land use directly under and around the existing electric wires becomes active, and there is a situation where the height of the existing electric wires from the ground may be insufficient due to environmental changes due to construction of residential land and factory land. May occur.

  On the other hand, with the increase in power demand, the construction of new electric lines by electric power companies is planned. In constructing new electric lines, in addition to securing new track sites, From the point of view, there are cases in which it is not possible to gain the understanding of local governments and residents about the construction of new electric lines in urban areas and residential areas. For this reason, electric power companies tend to implement replacement work for increased capacity wires to existing wires instead of constructing new wires. However, there is a shortage of the separation distance from the building due to an increase in the looseness of the wire due to this increase in capacity, an increase in the weight of the wire due to an increase in the transmission capacity, and an increase in the amount of loosening of the wire due to an increase in the wire temperature. And there is a situation where the ground clearance is insufficient.

  As countermeasures against such a lack of separation from the building and a lack of ground clearance, rebuilding of the steel tower is required to further increase the ground clearance of the existing electric wires. When implementing this rebuilding work, from the viewpoint of stable power supply, after constructing a temporary route once (temporary work), the steel tower will be rebuilt. However, this temporary construction requires a large amount of construction cost, and it is often difficult to secure a site for the temporary route.

  In view of such a current situation, various methods for raising an existing steel tower without performing temporary work have been proposed. As an example of this type of conventional steel tower raising method, for example, after adding a new steel tower to the top of the existing steel tower, multiple stages of wires are transferred to the existing steel tower for each left and right circuit during a power outage, There is a steel tower raising method in which the arm metal is removed, a multi-stage electric wire arm metal is newly installed in the new steel tower, and each electric wire is transferred from the existing steel tower to the new electric wire arm metal (for example, cited as the prior art in Patent Document 1) (See FIG. 1).

  As another example of the conventional steel tower raising method, for example, there is a steel tower raising method in which the entire existing steel tower is raised in a so-called overhead state where electric wires are installed, and a new steel tower is constructed at the lower end of the existing steel tower (for example, patent References 2, 3 and 6).

  As another example of the conventional steel tower raising method, for example, the steel tower is raised while the upper part of the existing steel tower is overhanged, and a new steel tower is constructed in the middle between the upper part of the existing steel tower and the lower part of the existing steel tower. There is a construction method (for example, see Patent Documents 4 and 7 to 9).

  As yet another example of the conventional steel tower raising method, for example, with the left and right lines energized, a new steel tower lower layer that does not reach the left and right lines is constructed around the existing tower, and the left and right lines are alternated. In the state where the power failure occurred, after constructing the new steel tower middle layer at the upper end of the lower part of the new steel tower to a predetermined height, and adding the upper part of the new steel tower to the upper end of the new steel tower, There is a steel tower raising method in which a brace for supporting an electric wire or an electric wire is transferred to the upper part of the new steel tower (see, for example, Patent Document 5).

Japanese Patent Laid-Open No. 53-110235 JP 54-124539 A JP 54-124540 A JP-A-5-214845 JP 2000-345740 A JP 2002-106207 A JP 2002-147063 A JP 2005-188080 A JP 2005-256343 A

  However, the conventional steel tower raising methods described in Patent Documents 2 to 9 require the use of a special large-sized machine device such as a lifting device or a hydraulic climbing device. Or there was a problem that it was difficult to secure a working site in a residential area. Since this conventional steel tower raising method uses a special large-sized machine device, it requires days for operations such as carrying in to the site, assembling, dismantling, removing, etc., and there is also a problem that construction costs increase. .

  On the other hand, the steel tower raising method cited as the prior art of Patent Document 1 does not require a special large-sized machine device unlike the conventional steel tower raising method described in Patent Documents 2 to 9, so that the raising work is not necessary. It will be easy. However, since a new steel tower is added to the top of the existing steel tower, it will be difficult to carry out the raising work depending on the size and structure of the main pillar material and arm metal for attaching the arm metal and the strength of the existing steel tower and foundation. There was a problem.

  Moreover, the steel tower raising method mentioned as the prior art of the above-mentioned Patent Document 1 is a method of adding a new steel tower to the top of the existing steel tower, and then, for each left and right circuit during a power outage, a new metal tower with a brace for supporting a plurality of stages of wires. Since the wires and wires are relocated in order, the work for each of the upper-phase wires, middle-phase wires, and lower-phase wires cannot be performed. Therefore, it is difficult to shorten the power outage period so as not to hinder power supply even during the raising work, and it is difficult to quickly recover from the power outage in a short time.

  The object of the present invention is to shorten the power outage period so as to minimize the trouble of power supply during the raising work from the viewpoint of stable power supply, and to quickly recover from the power outage in a short time. An object of the present invention is to provide a steel tower raising method that is possible, and a temporary arm for use in the method.

[1] In order to achieve the above object, the present invention is a first embodiment comprising a plurality of phase wires that are located below a ground wire provided at the top of an existing steel tower and are provided vertically on one side of the existing steel tower. In a state in which one circuit and a second circuit made up of a plurality of phase wires provided on the other side of the existing tower are alternately powered down, the existing tower body provided with the upper phase cables of the existing tower is temporarily installed. Temporary arm attachment process of attaching an arm, transferring the ground wire and the upper phase electric wire to the temporary arm, and removing the ground wire supported by the existing tower body and the existing arm metal of the upper phase electric wire Cutting and removing the existing tower body that supports the existing arm metal, and a new tower body assembling step for assembling a new tower body at the top of the existing steel tower after the existing tower body is cut and removed, and In the state where the 1st line and the 2nd line were alternately blacked out, a new arm was attached to the new tower, The ground lines and transferred to the upper phase wires to Tadashiude gold, said providing tower raising method characterized by comprising a new cross-arm mounting step of removing the temporary cross-arm.
[2] Further, in the present invention, the temporary arm attachment step includes the upper-phase electric wire provided on the existing steel tower in a state where the first line out of the first line and the second line is blacked out. A ground wire and a first temporary arm of the upper phase electric wire are attached to the first line side of the existing tower, and the ground wire and the upper phase electric wire of the first line are moved to the first temporary arm metal, In the state where the first existing arm metal removal step of removing the existing arm metal of the ground line and the upper phase electric wire on the one line side, the energization of the first line is resumed, and the second line is blacked out, A ground wire and a second temporary arm of the upper phase electric wire are connected to the first temporary arm and attached to the second line side of the existing tower provided with the upper phase electric wire of the existing steel tower, and the second temporary wire is attached. Transfer the ground wire on the second line side and the upper-phase electric wire to the armrest, and remove the existing armature on the ground wire and the upper-phase electric wire on the second line side. The new arm attachment step includes a ground removal step on the first line side of the new tower with the first line out of the first line and the second line. A first new arm of a wire and the upper phase electric wire is attached, the ground wire on the first line side and the upper phase electric wire are transferred to the first new arm, and the first temporary arm is removed. In the state where one temporary arm metal removal step, energization of the first line is resumed, and the second line is blacked out, the ground line and the upper-phase electric wire are connected to the second line side of the new tower. 2 A new armor is connected to the first armor and attached, the ground wire on the second line side and the upper phase wire are moved, and the second armor is removed to remove the second armor A steel tower raising method characterized in that it includes a process.
[3] Furthermore, in order to achieve the above object, the present invention provides a temporary ground wire arm that temporarily supports the ground wire, a temporary wire arm metal that temporarily supports the upper phase wire, the temporary ground wire arm, In the tower raising method according to the above [1] and [2], the temporary tower body main material for temporarily installing the temporary wire arm on the existing tower has a three-dimensional truss structure skeleton. Provide the temporary armor to be used.

  According to the present invention, when raising the steel tower, by attaching a temporary arm metal to the existing tower body provided with the upper phase electric wire of the existing steel tower, the work is performed for each phase electric wire on the first line side and the second line side. Therefore, even during the raising work, the power failure period can be shortened so as to minimize the trouble of power supply, and the power failure can be quickly recovered in a short time. In addition, it is possible to carry out the raising work in a narrow site without introducing special large machinery, so it is a small raising work without requiring special equipment or a large construction site. The construction period and construction costs can be reduced. Also, with the temporary tower attached to the existing tower, a new tower with a new arm attached to the upper part of the tower is installed, so that work on the upper-phase electric wires on the first and second lines can be performed. It is possible to carry out power transmission and restore power transmission with the middle and lower phase wires intact, even during construction or when construction is interrupted. it can.

(A) is a front view which shows typically the whole structure of an existing steel tower, (b) is a side view of an existing steel tower. (A)-(c) is a 1st process work figure of the 1st (right side line) existing arm metal removal process which shows the steel tower raising method which is a suitable 1st embodiment concerning the present invention later on. . (A)-(c) is a 2nd process work figure of the 2nd (left side line) existing arm metal removal process which shows a steel tower raising method in order. (A) And (b) is a 3rd process work drawing of the new tower assembly upper process which shows a steel tower raising method in order. (A)-(c) is a 4th process work figure of the 2nd (left side line) temporary arm metal removal process which shows a steel tower raising method in order. (A)-(c) is a 5th process work figure of the 1st (right side line) temporary arm metal removal process which shows a steel tower raising method in order. (A) is a front view schematically showing a portion of the temporary arm metal applied to the steel tower raising method, (b) is a side view of the temporary arm metal, and (c) is a plan view of the temporary arm metal. (D) is a top view of the existing armrest part which the temporary electric wire armature which is one component of a temporary armrest attaches. (A) is a figure which shows typically the reinforcement structure by a new interruption material, (b) is a figure which shows the reinforcement structure by a new reinforcement main pillar material typically, (c) is the AA line of (b). It is arrow sectional drawing. (A) is a schematic side view which shows the example of reinforcement of the existing foundation typically, (b) is a schematic plan view. (A) is a schematic side view which shows the other example of reinforcement of the existing foundation typically, (b) is a schematic plan view. (A) is a front view schematically showing another overall configuration of the existing steel tower, (b) is a process work diagram showing the steel tower raising method according to the second embodiment of the present invention, (c) is It is process work drawing which shows the next process of (b). (A) is a front view schematically showing still another overall configuration of the existing steel tower, (b) is a process work diagram showing the steel tower raising method according to the third embodiment of the present invention, (c) These are process work drawings which show the next process of (b).

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

In FIGS. 1A and 1B, reference numeral 1 indicating the whole schematically shows a typical example of an existing steel tower standing on the ground GL. This existing steel tower 1 is mainly composed of angle steel, and the lower ends of the four main column members 2,... 2 embedded in a foundation (not shown) and the main column member 2 are separated from each other in the height direction. 3 is provided with a plurality of horizontal members 3,... 3 laid between the column members 2, and a plurality of diagonal members 4,. On the top of the existing steel tower 1, a pair of left and right ground wire arms 5L, 5R are extended in the horizontal direction. Below the ground wire arm 5L, 5R, a pair of upper phase wire arms 6L, 6R, middle phase wire arms 7L, 7R, and lower phase wire arms 8L, 8R on both the left and right sides are spaced apart by a predetermined distance. It extends in the horizontal direction.

  In the illustrated example, two ground wires 9L and 9R for lightning protection are attached to the ground wire arms 5L and 5R, respectively. A pair of overhead power transmission lines (the first line and the second line) on both the left and right sides are connected to the upper phase electric wire arm 6L, 6R, the middle phase electric wire arm 7L, 7R, and the lower phase electric wire arm 8L, 8R, respectively. Upper phase electric wires 13L, 13R, middle phase electric wires 14L, 14R, and lower phase electric wires 15L, 15R are engaged via phase insulators 10L, 10R, middle phase insulators 11L, 11R, and lower phase insulators 12L, 12R. Has been.

[First Embodiment]
Hereinafter, with reference to FIGS. 1 to 7, the details of the raising method of the steel tower (the most standard AC three-phase vertical two-wire steel tower having two ground wires) according to the first embodiment will be described in order. Explained.

(Steel raising method)
1 to 7, the upper phase electric wire 13L, the middle phase electric wire 14L, and the lower phase electric wire 15L are collectively referred to as the left line 16L, and the upper phase electric wire 13R, the middle phase electric wire 14R, and the lower phase electric wire 15R are referred to as the right line 16R. Collectively. In addition, the upper phase wires 13L and 13R, the middle phase wires 14L and 14R, and the lower phase wires 15L and 15R indicated by white double circles are energized (live lines), and those indicated by white circles are interrupted (disconnected). Electric) state. Further, components newly installed in raising the existing steel tower 1 (new tower body 17, new ground wire arm 18L, 18R of suspension material and main material, new upper phase wire arm metal 19L of suspension material and main material, 19R, new mid-phase wire arm suspension members 6L1 and 6R1 for suspension materials, and components of temporary arm metal 49 to be temporarily installed and removed (temporary tower body main material 50, temporary ground wire between the suspension material and the main material Arms 51L and 51R, and temporary wire arms 52L and 52R of the suspension material and the main material are indicated by bold lines.

(First step)
First, the 1st process shown in Drawing 2 (a)-(c) is explained. In this first step, the temporary tower main member 50 is temporarily attached to the inside of the existing tower 1 that supports the existing upper-phase electric wire arms (hanging members) 6L, 6R in a state where the right line 16R is blacked out. A temporary ground wire arm (suspending material and main material) 51R and a temporary wire arm metal (suspending material) 52R are temporarily installed on the right line 16R side of the temporary tower body main material 50, and the temporary ground The ground wire 9R is moved to the wire arm 51R, and the upper phase wire 13R is moved to the temporary wire arm 52R. After that, the first existing arm removal process (first process) on the right line 16R side for removing the ground wire arm 5R and the upper phase wire arm 6R is one step of the temporary arm attachment process. This 1st process is performed through the following work procedures 1-3.

(Working procedure 1)
As work procedure 1, as shown in FIG. 2A, a power failure is confirmed in the right line 16 </ b> R serving as a work line, and grounding is attached. Next, the temporary tower body main material 50 is attached and temporarily installed inside the existing tower that supports the existing upper phase electric wire arm 6L, 6R. Next, the upper phase electric wire 13R is removed from the upper phase insulator series 10R of the upper phase electric wire arm 6R, and is deposited on the right line 16R side of the existing tower 1. Then, the following work procedure 2 is performed.

(Work procedure 2)
As the work procedure 2 following the work procedure 1, as shown in FIGS. 2 (a) and 2 (b), as a reinforcement of the lifting support force from the tip of the upper phase electric wire arm 6R to the tip of the ground wire arm 5R. A branch line 54 is attached. Next, the upper phase electric wire arm metal 6R (suspending material) of the existing tower 1 is removed, and the temporary ground wire arm 51R and the temporary electric wire arm metal (suspending material) 52R on the right line 16R side of the temporary tower main material 50. Install. Before removing the upper phase electric wire arm (hanging member) 6R, it is necessary to temporarily remove the upper phase electric wire 13R from the upper phase electric wire arm 6R and temporarily deposit it in the tower body of the existing body 1. Then, the following work procedure 3 is performed.

(Working procedure 3)
As the work procedure 3 following the work procedure 2, as shown in FIGS. 2B and 2C, the ground wire 9R is moved from the existing ground wire arm 5R to the temporary ground wire metal 51R. Subsequently, the upper phase electric wire 13R temporarily deposited on the right line 16R side of the existing tower 1 is moved to the upper phase insulator series 10R of the temporary electric wire arm 52R. Then, the ground wire arm 5R and the branch line 54 are removed from the right line 16R side of the existing steel tower 1. Thereby, the removal of the existing ground wire arm 5R and the upper phase wire arm 6R is completed, and the first step is completed.

(Second step)
As a second step subsequent to the first step, as shown in FIGS. 3A to 3C, energization of the right line 16R is resumed and the left line 16L is blacked out. In this state, the temporary ground wire arm (suspending material and main material) 51L and the temporary wire arm metal (suspending material) on the left line 16L side of the temporary tower body main material 50 by the same operation procedure as in the first step. 52L is attached and temporarily installed, and the ground wire 9L is moved to the temporary ground wire arm 51L, and the upper phase wire 13L is moved to the temporary wire arm metal 52L. After that, the second existing arm metal removal step (second step) on the left line 16L side where the ground wire arm 5L and the upper phase wire arm 6L are removed is one step of the temporary arm attachment process. This 2nd process is performed through the following work procedures 4-6.

(Working procedure 4)
As work procedure 4 following work procedure 3 in the first step, as shown in FIG. 3A, power failure / grounding is switched from right line 16R to left line 16L. Next, the upper phase electric wire 13L is removed from the upper phase insulator series 10L of the upper phase electric wire arm 6L and is deposited on the left line 16L side of the existing tower 1. Then, the following work procedure 5 is performed.

(Working procedure 5)
As the work procedure 5 following the work procedure 4, as shown in FIGS. 3A and 3B, a branch line is provided as a reinforcement of the lifting support force from the tip of the upper phase wire arm metal 6L to the tip of the ground wire arm metal 5L. 54 is attached. Next, the upper phase electric wire arm metal (suspending material) 6L of the existing tower is removed, and the temporary ground wire arm 51L and the temporary electric wire arm metal 52L are attached to the left line 16L side of the temporary tower body main material 50. As in the first step (work procedure 2), before removing the upper phase electric wire arm (hanging material) 6L, the upper phase electric wire 13L is once removed from the upper phase electric wire arm 6L and the existing body 1 is removed. It is necessary to temporarily deposit in the tower. Thereby, the attachment work to the existing steel tower 1 of the temporary arm metal 49 composed of the temporary tower body main material 50, the pair of temporary ground wire arms 51L and 51R on both the left and right sides, and the temporary electric wire arm metals 52L and 52R is completed. . Then, the following work procedure 6 is performed.

(Working procedure 6)
As the work procedure 6 following the work procedure 5, as shown in FIGS. 3B and 3C, the ground wire 9L is moved from the existing ground wire arm 5L to the temporary ground wire arm 51L. Subsequently, the upper-phase electric wire 13L temporarily deposited on the left line 16L side of the existing tower 1 is moved to the upper-phase insulator series 10L of the temporary electric wire arm 52L. Then, the ground wire arm 5L and the branch line 54 are removed from the left line 16L side of the existing tower 1. Thereby, the removal of the existing ground wire arm 5L and the upper phase wire arm metal 6L is completed, and the second step is completed.

(Third step)
After performing the said 2nd process, the 3rd process shown to Fig.4 (a) and (b) is performed. In this third step, the existing body supporting the existing ground wire arms 5L and 5R and the upper phase wire arms 6L and 6R is cut and removed in a state where the left line 16L is cut off. This is a new tower assembly assembling step (third step) in which the new tower body 17 is assembled on the top 30 (joint portion 30) of the later existing steel tower 1. This third step is performed through the following work procedures 7 and 8.

(Working procedure 7)
As the work procedure 7 following the work procedure 6 of the second process, as shown in FIG. 4A, the ground wire arm 5L, 5R and the horizontal members of the existing tower 1 for connecting and fastening the four main pillar members 2, ... 2 of the existing tower 1 supporting the upper phase wire arms 6L, 6R to the upper phase wire arms 6L, 6R The temporary tower body main material 50 is long enough to stand upright, and is cut so as to leave dimensions that allow the new tower body 17 to be provided, and the top 30 ( A joint 30) is formed. Remove the cut existing vehicle.

(Working procedure 8)
Next, as work procedure 8 following work procedure 7, as shown in FIG. 4 (b), a new tower body 17 is assembled on the joint 30 of the existing steel tower 1. Here, for example, the height of the new tower body 17 is 4 m. A work brace 53 is attached to the top of the assembled new tower body 17. Thereby, the 3rd process of a new tower assembly upper process is complete | finished. And it transfers to the following 4th process.

(4th process)
In the fourth step following the third step, as shown in FIGS. 5 (a) to 5 (c), a horizontal suspension material and a main suspension are formed on the left line 16L side of the new tower 17 in a state where the left line 16L is blacked out. The new ground wire arm 18L with the material and the new upper phase wire arm metal 19L with the suspension material and the main material are attached, and the ground wire 9L and the upper phase wire 13L are transferred to the new ground wire arm 18L, 19L. Thereafter, a temporary wire arm (suspending material and main material) 51L, 51R and a temporary electric wire arm metal (suspending material) 52L of the temporary arm metal 49 are removed. Step) is one step of a new arm attachment process. This 4th process is performed through the following work procedures 9-11.

(Working procedure 9)
As the work procedure 9 following the work procedure 8 of the third process, as shown in FIG. 5A, the left line 16L is left in the same state as the third process and the left side of the new tower 17 is left. A new ground wire arm 18L is attached to the line 16L side, and a new upper-phase wire arm 19L is attached to the lower position thereof so as to be connected and fastened to the horizontal member of the new tower body 17. Next, the ground wire 9L is moved from the temporary ground wire arm 51L to the new ground wire arm 18L. The temporary ground wire 55L is removed. Next, the upper phase electric wire 13L is removed from the upper phase insulator series 10L and temporarily deposited on the left line 16L side of the new tower 17. Then, the following work procedure 10 is performed.

(Working procedure 10)
As the work procedure 10 following the work procedure 9, as shown in FIGS. 5 (a) and 5 (b), the temporary wire arm (suspending material) 52L is removed and a new medium-phase wire arm (hanging) is placed at that position. Material) 6L1 is attached to the existing tower position where the upper phase electric wire arm 6L was connected. Prior to this work, the upper phase electric wire 13L is first removed from the temporary electric wire arm 52L and temporarily deposited in the new tower body 17, and then the new tower is started from the tip of the new middle phase electric wire arm (main material) 6L1. A branch line 54 is attached to the body 17 as a reinforcement of the lifting support force. Next, the intermediate phase electric wire 14L is moved from the existing intermediate phase electric wire arm 7L to the upper phase insulator series 10L of the upper phase electric wire arm 6L to be a new intermediate phase electric wire arm. Subsequently, the lower phase electric wire 15L is moved from the existing lower phase electric wire arm 8L to the intermediate phase insulator series 11L of the intermediate phase electric wire arm 7L. Then, the process proceeds to the next work procedure 11.

(Working procedure 11)
As the work procedure 11 following the work procedure 10, as shown in FIGS. 5B and 5C, the lower phase insulator series 12L of the lower phase electric wire 15L is moved to the new upper phase electric wire arm 19L. Subsequently, the upper phase electric wire 13L temporarily deposited on the left line 16L side of the new tower 17 is moved to the lower phase insulator series 12L which becomes the new upper phase electric wire arm 19L. Next, the existing lower phase electric wire arm brackets 8L and 8R are removed. Thereafter, the work brace 53 is switched from the left line 16L side to the right line 16R side. Thereby, a 4th process is complete | finished. Then, the process proceeds to the final fifth step.

(5th process)
As shown in FIGS. 6A to 6C, the final fifth process following the fourth process is the same as the fourth process in the state where the energization of the left line 16L is resumed and the right line 16R is blacked out. By the same work procedure, the new ground wire arm 18R of the suspended material and the main material and the new upper phase electric wire arm metal 19R of the suspended material and the main material are attached to the right line 16R side of the new tower body 17, The ground wire 9R and the upper phase electric wire 13R are moved to the new metal brace 18R, 19R. Thereafter, the first temporary arm metal removal step (fifth step) on the right line 16R side for removing the temporary ground wire arm (suspending material and main material) 51R and the temporary electric wire arm metal (suspending material) 52R of the temporary arm metal 49. ) Is one process of the new arm attachment process. This fifth step is performed through the following work procedures 12-14.

(Working procedure 12)
As the work procedure 12 following the work procedure 11 in the fourth step, as shown in FIG. 6A, the power failure / grounding is switched from the left line 16L to the right line 16R. Next, a new ground wire arm 18R is attached to the right line 16R side of the new tower body 17, and a new upper phase electric wire arm metal 19R is attached to the lower position thereof so as to be connected and fastened to the horizontal member of the new tower body 17. Next, the ground wire 9R is moved from the temporary ground wire arm 51R to the new ground wire arm 18R. The temporary ground wire 51R is removed. Next, the upper phase electric wire 13R is removed from the upper phase insulator series 10R and temporarily deposited on the right line 16R side of the new tower body 17. Then, the following work procedure 13 is performed.

(Working procedure 13)
As the work procedure 13 following the work procedure 12, as shown in FIGS. 6A and 6B, the temporary electric wire arm (suspending material) 52R is removed, and a new middle-phase electric wire arm (hanging) is placed at that position. Material) Attach 6R1 to the existing tower position where upper phase electric wire arm 6R was connected. Prior to this work, first, the upper phase electric wire 13R is removed from the temporary electric wire arm 52R and temporarily deposited in a new tower, and then the new tower 17 is started from the tip of the new middle phase electric wire arm (main material). A branch line 54 is attached as a reinforcement of the lifting support force. Next, the middle-phase wire 14R is moved from the existing middle-phase wire arm 7R to the upper-phase insulator series 10L of the upper-phase wire arm 6R that becomes a new middle-phase wire arm. Subsequently, the lower phase electric wire 15R is moved from the existing lower phase electric wire arm 8R to the middle phase insulator string 11R of the intermediate phase electric wire arm 7R. Then, the process proceeds to the next work procedure 14.

(Working procedure 14)
FIG. 6C shows a final work procedure 14 following the work procedure 13. 6B and 6C, the lower phase insulator series 12R of the lower phase electric wire 15R is moved from the existing lower phase electric wire arm 8R to the new upper phase electric wire arm 19R. Subsequently, the upper phase electric wire 13R temporarily deposited on the right line 16R side of the new tower body 17 is moved to the lower phase insulator series 12R that becomes the new upper phase electric wire arm bracket 19R. Next, the work arm 53, the lower phase electric wire arm 8R, and the temporary tower main material 50 are removed. Thereafter, energization of the right line 16R is resumed. Thus, all the steps from the first step to the fifth step are completed, and the existing steel tower 1 is raised to a predetermined height.

(Structure of the temporary arm metal)
7 (a) to 7 (d) are typical examples of a temporary arm as a bridging machine for transferring the ground wires 9L, 9R and the upper phase electric wires 13L, 13R from the existing tower 1 to the new tower 17. A typical example is shown schematically. The temporary arm metal 49 includes temporary ground wire arms 51L and 51R that temporarily support the ground wires 9L and 9R, temporary wire arm metals 52L and 52R that temporarily support the upper phase electric wires 13L and 13R, and temporary ground wire arms. A structure of a three-dimensional truss structure is constructed by the temporary tower body main material 50 for temporarily installing 51L, 51R and temporary electric wire arms 52L, 52R on the existing steel tower 1. In the illustrated example, the temporary ground wire arms 51L and 51R and the temporary wire arm metals 52L and 52R are attached symmetrically with the temporary tower body main material 50 interposed therebetween, and have the same structure. Accordingly, only the temporary ground wire arm 51R and the temporary wire arm 52R will be described.

  As shown in FIGS. 7 (a) to 7 (c), the temporary tower body main material 50 is a sub-material such as a horizontal material 50b and a diagonal material 50c between four main pillar materials 50a,... 50a having a quadrangular pyramid shape. It is formed into a three-dimensional truss structure combining materials. On the other hand, the temporary ground wire 51R includes a pair of left and right suspension members 51R1 and 51R1 horizontally attached to the upper portion of the main pillar member 50a, and a pair of left and right main members 51R2 attached obliquely to the lower portion between the two. 51R2 and a horizontal member 51R3 and a diagonal member 51R4 are combined with bolts and nuts via a reinforcing plate between the two to form a three-dimensional truss structure. A ground wire plate 51R5 that temporarily supports the ground wire 9R is attached to the tip end portion of the temporary ground wire arm formed by the hanging material 51R1 and the main material 51R2.

  As shown in FIGS. 7A and 7D, the temporary electric wire arm 52R includes a horizontal member 6R3 and a vertical member 6R4 on a pair of left and right suspension members 52R1 and 52R1 attached obliquely to the upper portion of the main column member 50a. , And diagonal members 6R5 and the like, and a pair of existing upper phase electric wire arm brackets 6R on both sides attached to the existing main pillar member 2 are fastened with bolts and nuts via plates, and combined. A three-dimensional truss structure is formed. An electric wire plate 52R2 that temporarily supports the upper phase electric wire 13R is attached to the tip of the triangular pyramid formed by the suspension members 52R1, 52R1 and the horizontal main members 6R, 6R.

  In the first embodiment, in constructing the temporary electric wire arms 52L and 52R, the existing suspension members 6L1 and 6R1 are removed from the existing upper phase wire arms 6L and 6R, and the suspension material is removed. Although 52L and 52R are illustrated as being newly installed, the temporary armor according to the illustrated example illustrates one configuration example, and the shape and structure thereof are not limited to the illustrated example. is there.

  According to the steel tower raising method constructed as described above, the temporary tower body main material 50, the temporary electric wire arm metal 51L, 51R, and the temporary ground wire arm metal 52L, 52R are combined with the temporary arm metal 49 in the truss structure. By cutting the existing ground wires 9L and 9R and the existing upper phase wires 13L and 13R, cutting and removing the existing body supporting the existing ground wire arms 5L and 5R and the upper phase wire arms 6L and 6R. Thus, it becomes possible to quickly return the existing electric wire to the energized state in a short time during the raising work or even when the work is interrupted.

  Work procedures 9 and 10 in the fourth step according to the first embodiment {FIGS. 5A and 5B}, and work procedures 12 and 13 in the fifth step {FIGS. 6A and 6B} 1 illustrates an example of attaching the new ground wire arm 18L, 18R and the new upper phase wire arm metal 19L, 19R, but is not limited to this. Depending on the top structure of the existing steel tower, the arm metal structure, and the condition of the power failure, the ground wire arm 5L, 5R and the lower phase electric wire arm metal 8L, 8R removed in the first embodiment can be used.

  As shown in FIG. 1B, the raised height of the existing steel tower 1 is preferably matched with the electric wire vertical phase distance H (for one electric wire) of the existing steel tower 1. As an example, if the vertical phase distance H of the existing tower 1 is 4 m, for example, the raised height of the existing tower 1 is 4 m. Temporarily, the raised height of 4 m is insufficient, and when further raised, it becomes 8 m (4 m × 2 phases of electric wire). By matching the raised height of the existing tower 1 with the distance H between the vertical phases of the electric wires, it becomes a simple operation for each phase of the electric wires, and the remaining two-phase electric wires are left attached to the existing arm metal or new arm metal. Become. Therefore, it becomes possible to return to the energized state in a short time during the raising work.

  The tower raising method according to the first embodiment can be applied to a wide range of existing transmission lines in Japan and overseas, and has a track record of application to a suspended tower type existing tower up to a horizontal angle of 15 °. However, it is optimal to apply to a suspended steel tower with a horizontal angle of 3 ° or less, and the tower body widths of the upper phase electric wire portion, middle phase electric wire portion, and lower phase electric wire portion of the existing steel tower 1 are the same size. In addition, it is desirable that the length and size of the electric wire arm have the same dimensions, and that the vertical intervals (the upper-middle interval and the middle-lower interval) of the electric wire arms are the same.

(Reinforcement work)
In order to assist the insufficient support strength with respect to the steel tower portion raised as described above, the steel tower and the foundation are reinforced as necessary.

(Steel tower reinforcement structure)
In the final work procedure 11 {FIG. 5 (c)} in the fourth step, the existing tower 1 is reinforced by inserting an interrupting material or replacing bolts, for example. During the raising work of the existing tower 1, when the reinforcement part of the existing tower 1 becomes a live line close work, it is preferable to carry out at the time of a power failure of the left line 16L or the right line 16R.

  In this 1st Embodiment, the reinforcement object part of a steel tower is the existing main pillar material 2 and the diagonal material 4, as shown to Fig.8 (a)-(c). As an example of the reinforcing structure of the main column member 2, as shown in FIG. 8A, a first interrupt member 20 that intersects the diagonal members 4, 4 is horizontally bolted between a large number of horizontal members 3. The second interruption member 21 is fastened and fixed obliquely between the main column member 2 and the diagonal member 4. With such a configuration, even if a force greater than the design load is applied to the existing tower 1, these interrupting materials 20 and 21 can compensate for insufficient strength.

  As an example of the reinforcing structure of the diagonal member 4, as shown in FIG. 8B, the reinforcing main column member 22 is arranged in a form overlapped with the outer surface of the existing main column member 2 and is double-bonded. As shown in FIG. 8C, bolts 23 are passed through the reinforcing main column member 22 and the outer surface of the existing main column member 2, and are fastened and fixed by nuts 24. With this configuration, it becomes possible to strengthen the proof stress of the existing tower 1 while the existing tower 1 is still built, and even if a force greater than the design load acts on the existing tower 1, each of the existing tower 1 The lack of strength in the member can be resolved.

(Reinforcement structure of foundation)
After the steel tower raising work in the fifth step, the existing foundation is reinforced. As an example of the reinforcement work, as shown in FIGS. 9A and 9B, the heads of the four-legged inverted T-shaped concrete columns 25,... 25 constituting the foundation of the existing tower 1 are ground GL. In this state, the concrete is placed so as to be continuous with the concrete struts 25, and a reinforcing foundation composed of the rectangular block-shaped reinforcing members 26 is constructed. Even in such a configuration, it becomes possible to individually strengthen the proof strength of the foundation of the existing steel tower 1 while the existing steel tower 1 is still built.

  As another example of the reinforcement work, as shown in FIGS. 10 (a) and 10 (b), concrete was placed so as to continue to the middle part of the four-legged inverted T-shaped concrete columns 25,... A mat-shaped first reinforcing member 27, a square pyramid-shaped second reinforcing member 28 in which concrete is cast so as to be continuous with the first reinforcing member 27 and the head of the concrete support 25, and a second A reinforcing foundation comprising a mat-like third reinforcing member 29 in which concrete is cast so as to be continuous with the upper inner surface of the reinforcing member 28 is constructed. With this configuration, it is possible to reinforce the strength of the foundation of the existing steel tower 1 while the existing steel tower 1 is still built without requiring large-scale reinforcement work such as concrete replacement of the foundation of the existing steel tower 1. Become.

(Effects of the first embodiment)
According to the steel tower raising method having the above configuration, the following effects can be obtained.
(1) By attaching the temporary arm 49 to the existing tower body provided with the upper phase wires 13L, 13R of the existing tower 1, the upper phase wires 13L, 13R, the middle phase wires 14L, 14R of the left and right lines 16L, 16R, Since the upper phase wire arm 6L, 6R, the middle phase wire arm 7L, 7R and the lower phase wire arm 8L, 8R can be removed and moved for each lower phase wire 15L, 15R, Or, even if the construction is interrupted, the power failure can be quickly restored in a short time so as to minimize the trouble of power supply.
(2) At the top of the existing steel tower 1, the temporary tower body main material 50, temporary electric wire arm metal 51L, 51R, and temporary ground wire arm metal 52L, 52R are combined with a temporary arm metal 49 combined with a structure of a three-dimensional truss structure. By cutting the existing ground wires 9L and 9R and the existing upper phase wires 13R and 13L, cutting and removing the existing body supporting the existing ground wire arms 5L and 5R and the upper phase wire arms 6L and 6R. Thus, the new tower body 17 can be efficiently assembled at the joint portion of the existing tower 1. Thereby, while being able to shorten the power failure period during the raising work, it becomes possible to quickly recover from the power failure in a short time.
(3) Furthermore, by moving the existing ground wires 9L and 9R and the existing upper phase wires 13R and 13L to the temporary arm 49, the work of the upper phase wires can be performed first, Even in the middle or when the construction is interrupted, it is not necessary to interrupt the power supply of the middle-phase wire and the lower-phase wire, and power transmission can be restored without delay, so that it is possible to minimize troubles in power supply.
(4) By setting the raised height to the distance H between the vertical phases of the electric wires, it becomes a simple work process for each phase of the electric wires, and the remaining two-phase electric wires are attached to the existing arm metal or new arm metal, All-day power outage or power outage line under construction can be restored (energized) quickly and quickly.
(5) Since only a small manual / power tool can be used without introducing special / large heavy machinery, raising work on a very limited site in existing steel towers located in urban areas and densely populated areas Can be implemented efficiently.
(6) Restriction conditions (one-side line power outage time, duration), construction details and procedures within the limited one-side line alternating power outage period (one side line is in a live state) Skilled technology is not required, the construction period is shortened, and the construction cost is reduced.
(7) It is preferable to set the load increase to the existing tower caused by raising the height within the range of tolerance (tolerance) between the design load of the tower and the actual application conditions. Even if it exceeds, it can be dealt with by steel tower reinforcement and foundation reinforcement.

[Second Embodiment]
As described above, the first embodiment of the present invention is for an AC three-phase vertical two-line tower having two ground wires. As the second embodiment, an example of one ground wire (
The main pillar material supporting the ground wire is a quadrilateral structure).

  FIGS. 11A to 11C schematically show an example of the steel tower raising method according to the second embodiment. Note that, in FIGS. 11A to 11C, substantially the same members as those in the first embodiment are denoted by the same member names and symbols. Therefore, a detailed description of substantially the same members as those in the first embodiment is omitted. Further, only the work process of the first embodiment related to the work of the second embodiment is applied.

(Steel raising method)
A significant difference from the first embodiment is that in the first embodiment, two ground wires 9L and 9R are provided at the top of the existing steel tower 1 as shown in FIG. In the second embodiment, as shown in FIG. 11 (a), the terrain raising method in the three-phase two-line power transmission line is illustrated. As shown in FIG. It is in the point which illustrates the steel tower raising method in the three-phase two-line power transmission line provided with.

(First step)
The first step according to the second embodiment can be performed by the same operation as the first step according to the first embodiment. In this first step, as shown in FIGS. 11 (a) to 11 (c), the temporary tower body main material 50 is attached to the upper phase electric wire arms 6L and 6R in a state where the left line 16L serving as a work line is blacked out. Attach to the inside of the existing building to support. Next, the upper-phase electric wire 13L is temporarily deposited from the upper-phase electric wire arm 6L to the left line 16L side of the existing tower 1. Further, the existing upper phase electric wire arm 6L is removed and removed. Next, the temporary ground wire arm 51L of the suspension material and the main material is attached to the left line 16L side of the temporary tower body main material 50, and the temporary upper phase wire arm metal 52L is attached. Next, one ground wire 9 is moved from the existing ground wire arm 5 to the temporary ground wire 51L, and the upper phase wire 13L temporarily deposited on the left line 16L side of the existing tower 1 is used as the temporary phase wire arm. Move to the upper phase lion series 10L of gold 52L. Thereby, a 1st existing armrest removal process (1st process) is complete | finished.

(Second step)
The second step subsequent to the first step can be performed by the same operation as the second step according to the first embodiment. In the second step, the energization of the left line 16L is resumed and the existing upper-phase wire arm 6R is removed and removed in the same manner as in the first step while the right line 16R is powered off. Then, the temporary electric wire arm 52R is attached to the right line 16R side of the existing tower 1, and then the upper electric wire 13R is attached to the upper phase insulator 10R of the temporary electric wire arm 52R to remove the second existing arm metal (first 2 steps) are completed. Thus, a temporary arm metal 49A constituted by the temporary tower body main material 50, one temporary ground wire arm 51L, and a pair of temporary electric wire arms 52L and 52R on both right and left sides, as shown in FIG. 11 (b). Temporary to the existing tower 1

(3rd to 5th steps)
The third step (new tower assembly upper step) following the second step, the fourth step (second temporary arm metal removal step), and the fifth step (first temporary arm metal removal step) are the first step. It can be carried out by substantially the same work as the third to fifth steps according to the embodiment. As shown in FIGS. 11 (b) and 11 (c), the existing vehicle body supporting the existing one ground wire arm 5 and the upper phase wire arms 6 </ b> L and 6 </ b> R is cut and removed. Thereafter, the existing steel tower 1 is raised to a predetermined height by sequentially performing the same operations as in the third to fifth steps according to the first embodiment.

(Effect of the second embodiment)
According to the steel tower raising method according to the second embodiment, in addition to the first embodiment, one is provided at the top of the square pyramid of the existing steel tower 1 by application of the form and structure of the temporary arm metal. Even if the ground wire 9 is installed, the existing steel tower 1 can be efficiently raised.

[Third Embodiment]
As in the second embodiment, there is only one ground wire, but the ground wire support structure is different (
The structure in which the main pillar material for supporting the ground wire also serves as the support for the suspension member of the upper phase electric wire armrest is described below as a third embodiment.

  FIG. 12 schematically shows an example of the steel tower raising method according to the third embodiment. In FIG. 12, the same member names and reference numerals are assigned to substantially the same members as those in the above embodiments. Therefore, the detailed description regarding the substantially same member as the said 2nd Embodiment is abbreviate | omitted. Moreover, only the work process of the said 1st and 2nd embodiment relevant to the operation | work of 3rd Embodiment is applied and implemented.

(Steel raising method)
A significant difference from the second embodiment is that in the second embodiment, as shown in FIG. 11 (a), a pair of left and right upper-phase electric wire arms 6L and 6R are connected to the existing tower 1. In this third embodiment, as shown in FIG. 12 (a), a pair of upper-phase wire arms 6L and 6R on both the left and right sides are grounded. The point is that it is configured to be attached to the top of the wire arm 5.

(First step)
The tower raising method according to the third embodiment can be carried out by the same work procedure as the first step according to the first embodiment. In this first step, as shown in FIGS. 12 (a) to 12 (c), the temporary tower body main material 50 is attached to the upper-phase electric wire arms 6L and 6R in a state where the left line 16L serving as a work line is blacked out. Attach to the inside of the existing building to support. Next, the upper-phase electric wire 13L is temporarily deposited from the upper-phase electric wire arm 6L to the left line 16L side of the existing tower 1. Further, the upper phase electric wire arm 6L is removed and removed. Then, the temporary upper-phase electric wire arm metal 52L of the suspension material and the main material is attached to the left line 16L side of the temporary tower main material 50. Next, one ground wire 9 is moved from the existing ground wire arm 5 to the temporary electric wire arm 52L. Subsequently, the upper phase electric wire 13L temporarily deposited on the left line 16L side of the existing tower 1 is moved to the upper phase insulator series 10L of the temporary upper phase electric wire arm 52L. Thereby, a 1st existing armrest removal process (1st process) is complete | finished.

(Second step)
The second step subsequent to the first step can be performed by the same work procedure as the second step according to the first embodiment. In the second step, the energization of the left line 16L is resumed and the existing upper-phase wire arm 6R is removed and removed in the same manner as in the first step while the right line 16R is powered off. Then, the temporary electric wire arm 52R is attached to the right line 16R side of the existing tower 1, and then the upper electric wire 13R is sequentially attached to the upper phase insulator 10R of the temporary electric wire arm 52R to remove the second existing arm metal ( The second step) ends. Thereby, the temporary arm metal 49B comprised of the temporary tower body main material 50 and the pair of temporary electric wire arms 52L and 52R on the left and right sides is transferred to the existing steel tower 1 as shown in FIGS. 12 (b) and (c). Temporary.

(3rd to 5th steps)
The third step (new tower assembly upper step) following the second step, the fourth step (second temporary arm metal removal step), and the fifth step (first temporary arm metal removal step) are the first step. It can be carried out by substantially the same work procedure as the third to fifth steps according to the embodiment. As shown in FIG. 12 (c), the existing body supporting the existing ground wire arm 5 and the upper phase wire arm metal 6L, 6R is cut and removed. Thereafter, the existing steel tower 1 is raised to a predetermined height by sequentially performing the same operations as in the third to fifth steps according to the first embodiment.

(Effect of the third embodiment)
According to the steel tower raising method according to the third embodiment, in addition to the first embodiment, the main pillar material 2 supporting the ground wire arm 5 and the upper phase wire arm 6L, 6R are supported. Even if it is the existing steel tower 1 which also serves as the main pillar material 2 to perform, the existing steel tower 1 can be efficiently raised by application of the form and structure of a temporary arm metal.

  As is clear from the above description, the optimum type of steel tower using the raising method according to the above embodiment can include a suspension type, but is not limited to this, for example, a tension type or Even if it is a double angle type | mold, the application of the raising method by the said embodiment is possible. However, the tension type and the heavy angle type have a large load on the track in the vertical direction and the horizontal direction at the same time. It is necessary to change the construction method. Moreover, although the case where the upper-phase electric wire, the middle-phase electric wire, and the lower-phase electric wire are single conductors has been described in the above embodiment, the present invention can be similarly applied to a multi-conductor composed of a plurality of wires.

  In addition, this invention is not limited to the said embodiment and illustration example, Naturally also includes the technical range which those skilled in the art can change easily from those embodiment and illustration example. It is.

DESCRIPTION OF SYMBOLS 1 Existing steel tower 2 Main pillar material 3 Horizontal material 4 Diagonal material 5L, 5R Ground wire arm 6L, 6R Upper phase electric wire arm (Suspension material + Main material)
6L1, 6R1 New middle-phase wire arm (suspended material + main material)
6L2, 6R2 Main material (Main material of upper phase wire arm) = Main material of new medium phase wire arm
6L3, 6R3 Horizontal material 6L3, 6R4 Vertical material 6L5, 6R5 Diagonal material 7L, 7R Middle phase wire arm (suspended material + main material)
8L, 8R Lower phase wire arm (Suspension material + Main material)
9L, 9R Ground wires 10L, 10R Upper phase insulators 11L, 11R Middle phase insulators 12L, 12R Lower phase insulators 13L, 13R Upper phase wires 14L, 14R Middle phase wires 15L, 15R Lower phase wires 16L Left line 16R Right line 17 New tower 18L, 18R New ground wire arm 19L, 19R New upper phase wire arm metal 20, 21 Interrupt material 22 Reinforcement main pillar material 23 Bolt 24 Nut 25 Concrete support 26-29 Reinforcement member 30 Joint part 49 Temporary arm Gold 49A Temporary arm 49B Temporary arm 50 Temporary tower main material 50a Main pillar material 50b Horizontal material 50c Diagonal material 51L, 51R Temporary wire arm metal (suspended material + main material)
51L1, 51R1 Suspension material 51L2, 51R2 Main material 51L3, 51R3 Horizontal material 51L4, 51R4 Diagonal material 51L5, 51R5 Ground plate 52L, 52R Temporary wire arm (Suspension material + Main material)
52L1, 52R1 Suspension material 52L2, 52R2 Electric wire plate 53 Work brace 54 Branch line GL Ground H Distance between electric wires vertical phase

Claims (3)

A first line consisting of a plurality of phase wires provided on one side of the existing tower and above and on the other side of the existing tower, located below the ground line provided at the top of the existing tower. In a state where the second line composed of a plurality of phase wires is alternately cut off, a temporary arm is attached to the existing tower provided with the upper phase electric wire of the existing tower, and the ground wire is attached to the temporary arm. Transfer the upper phase electric wire, a temporary arm attachment step for removing the ground wire supported by the existing tower body and the existing arm metal of the upper phase electric wire,
Cutting and removing the existing tower body that supports the existing arm metal, and assembling a new tower body at the top of the existing steel tower after the existing tower body is cut and removed; and the first line And a new arm metal which attaches a new arm metal to the new tower body, transfers the ground wire and the upper phase electric wire to the new arm arm, and removes the temporary arm arm in a state where power is alternately interrupted at the second line. A steel tower raising method characterized by comprising an attachment step. The temporary arm attachment process includes
Of the first line and the second line, the ground line and the upper phase electric wire are connected to the first line side of the existing tower provided with the upper phase electric line of the existing tower in a state where the first line is blacked out. The first wire is attached, the ground wire on the first line side and the upper phase electric wire are transferred to the first wire arm, and the ground wire on the first line side and the existing arm metal on the upper phase wire 1st existing arm removal process to remove
In the state where the energization of the first line is resumed and the second line is cut off, the ground wire and the upper phase wire are connected to the second line side of the existing tower where the upper phase wire of the existing tower is provided. A second temporary arm is connected to and attached to the first temporary arm, the ground wire on the second line side and the upper phase electric wire are moved to the second temporary arm, and the second line side Including a ground wire and a second existing arm removal step of removing the existing arm metal of the upper phase electric wire,
The new arm attachment process includes
With the first line out of the first line and the second line, the first line of the new tower and the first new arm of the upper-phase wire are attached to the first line side of the new tower, A first temporary arm removal step of transferring the ground wire on the first line side and the upper phase electric wire to the first new arm and removing the first temporary arm;
In the state where the energization of the first line is resumed and the second line is blacked out, the second new arm of the ground wire and the upper phase electric wire is placed on the second line side of the new tower body. A second metal arm removal step of connecting and attaching to a new metal arm, transferring the ground wire on the second line side and the upper phase electric wire, and removing the second metal arm. The steel tower raising method according to claim 1.   Temporary ground wire arm that temporarily supports the ground wire, temporary wire arm wire that temporarily supports the upper phase wire, and a temporary tower that temporarily installs the temporary ground wire arm and the temporary wire arm metal to the existing body. The temporary arm metal used in the steel tower raising method according to claim 1 or 2, wherein the main body material has a skeleton having a three-dimensional truss structure.

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