JPH0421791B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for connecting an existing tower to a new ground without performing temporary construction on an existing power transmission line, and in which the existing tower is connected from the old ground to the new ground while power is being transmitted. .

(Prior art) When there is an existing steel tower 2 on the hill 1 as shown in Fig. 12A, due to recent residential land development and land improvement, etc.
Old steel tower routes often have to be relocated. However, the relocation of the tower was delayed compared to the land preparation, and as shown in Figure 12B, only the ground near the tower 2 was left behind, like a small hill 4, compared to the other ground 3 that had been cut out. However, relocating the tower requires land acquisition, which increases costs and time. As a countermeasure for this, hill 4
The steel tower is being reconstructed on new ground 3. The procedure is as shown in Figure 12C.
A steel tower 5 was temporarily constructed next to the hill, and after a temporary power outage, the line was transferred from the old steel tower 2 to the new steel tower 5. The old steel tower 2 was dismantled as shown in D, and then the hill 4 was built by cutting the ground as shown in E. Except for this, a new steel tower 6 was built at the location where hill 4 was located as shown in F, and the line was transferred from tower 5 again under power outage.
Next, G is dismantling temporary steel tower 5. However, in this case as well, complicated adjustments due to a temporary power outage on the line and troublesome land work for installing the temporary tower 5 are unavoidable.

(Objective of the Invention) An object of the present invention is to make it possible to connect an existing steel tower from an old ground to a new ground while transmitting power without having to perform temporary construction on an existing power transmission line.

(Structure of the Invention) The present invention involves temporarily supporting each tower leg of a former steel tower on the old ground, and then excavating a deep foundation, including removing the old foundation, using earth retaining material at the lower extension of the old tower leg. After the excavation was completed, a new foundation was installed and backfilled to the future ground level, the new foundation and the old tower base were connected with main pillar materials, and after providing support to prevent buckling, the main pillar was removed, excluding the temporary support material. This is a method of connecting the legs of an existing steel tower, in which a load is applied to the timber, the earth retaining material and shoring are removed, and the upper material is assembled in sequence, while the earth is cut and removed to the new ground.

(Example) Figure 1 shows an outline of the construction method of the present invention. From a state where the existing steel tower 2 is on top of the hill Aya 1 as shown in A, to a situation where only the ground near the steel tower 2 is a slightly elevated hill due to surrounding housing land development etc. If left in 4, tower pedestal 2a like B and C
A new foundation 10 is constructed on the future ground 3 by deep foundation digging while temporary supporting one by one on the ground, and the new foundation 10 and the old tower pedestal 2a are connected with the main pillar material 11, and then the hill 4 is cut out. This is a method to obtain a new steel tower 6 by essentially adding tower legs to the old steel tower.

Next, the new construction method shown in Figure 1 will be explained in detail in the order of the steps. Second
The figure shows the temporary mounting process for tower legs, and construction will be carried out one leg at a time. First, place H near the ground 4a (ground) of the tower pedestal 2a.
A reinforcing material or temporary support material 12 made of shaped steel or the like is temporarily fixed with jacks 13, and the load of the column leg 2a is temporarily supported by the jack up (in the case of a compression leg).
In the case of a towing leg, a temporary branch line is also used.

Figures 3 and 4 show the deep foundation excavation process.
As shown in FIG. 3, a hole 17 is excavated below the old tower pedestal 2a, including the removal of the old foundation 16, using earth retaining material 15 made of, for example, steel sheet piles, deck plates, or light groove steel. In this case, it is advantageous for the work to use a bolt assembly system for the retaining material 15, which is made up of a large number of divided pieces that can be disassembled in the circumferential direction and the vertical direction.

The reinforcing temporary support material 12 is arranged so as to cross the hole 17 as shown in FIG.
is located outside the hole 17. In addition to the temporary receiving material 12, another temporary receiving material 12a can also be added.

Figure 5 shows the process at the final stage of deep foundation excavation. That is, the excavation is proceeded, the new foundation is determined based on the future new ground 3, and the bottom expansion excavation is performed in the portion 18.
Since mortar is not used to backfill the earth retaining material 15 (the earth retaining material 15 will be removed later), a reinforcing material 15a such as a steel pipe pile or H-shaped steel pile is placed in contact with the circumference of the earth retaining material 15. Driving multiple pieces, earth retaining material 1
It is desirable to have 5 more firmly erected.

Figure 6 shows the basic concrete process.
After completing the excavation of the hole 17, installation reinforcement concrete work is performed for the new foundation 10, and the new ground 3 is subsequently backfilled with backfill soil 19.

Figures 7 and 8 show the main material assembly process.
The old tower foot 2a (old post) is jacked up
and the new foundation 10 are connected by the main pillar material 11. In this case, in order to prevent buckling of the main column 11 due to the load of the old tower pedestal 2a, a support 21 made of equilateral angle steel or groove steel is installed from the inner wall of the earth retaining material 15, for example, as shown in FIG. Apply many pieces in a cross shape. In addition,
The above-mentioned shoring 21 is not only fixed to the inner wall of the earth retaining material 15, but also installed and fixed by separately providing a pillar P for securing the shoring (indicated by a two-dot chain line in Fig. 8) near the inner wall of the earth retaining material 15. Good too. Jacking after shoring completion 1
3 and the temporary supporting material 12 are removed, and the load of the old tower pedestal 2a is applied to the new foundation 10 via the main pillar material 11.

Figure 9 shows the state of four-legged construction; in the case of a four-legged steel tower, the construction shown in Figures 2 to 8 is performed on the four legs.

Figure 10 shows the cutting and erection process, and after the new four-legged foundation is completed, cutting and removal will be carried out up to the new ground level 3.
At this time, the work of assembling the belly material 22 and removing the earth retaining material 15 (and reinforcing material 15a) is performed in sequence. 23 is a cut surface. In addition, when carrying out the above-mentioned cutting and assembling process, it is necessary to
For safety reasons, it is recommended to erect a column (indicated by a two-dot chain line in Fig. preferable.

Figure 11 shows the new steel tower 6 with legs attached to the main ground 3. The upper half of the new steel tower 6 is made up of the main part of the old steel tower 2, and the position of the old steel tower 2 has not changed at all. Not yet.

(Effects of the Invention) According to the present invention, the legs of the old steel tower can be connected underground as they are without temporary construction, and a new steel tower can be installed on the new ground, and the new tower can be installed next to the old steel tower for transfer purposes. It is possible to construct a new steel tower, which will be raised from the future ground (after cutting), at the original location of the existing steel tower, without requiring large-scale temporary equipment such as a temporary steel tower, and within a narrow construction area. This has the advantage of reducing complex power outage adjustments and cumbersome land management work, and there is also room to significantly reduce construction costs. This makes it possible to rebuild at the original location without temporary construction (power outages).

[Brief explanation of drawings]

Figure 1 is a schematic front view showing the new construction method according to the present invention;
2 to 11 are detailed views specifically showing the construction method of the present invention, and FIG. 12 is a schematic front view showing the conventional construction method. 1...Okaaya (old ground), 2...Old steel tower, 2a...Tower base, 3...New ground, 10...New foundation, 11...Main pillar material,
12...Temporary retaining material, 15...Earth retaining material, 16...Old foundation, 2
1... Shoring, 22... Belly material.

Claims (1)

[Claims] 1 After temporarily supporting each tower leg of the old steel tower on the old ground,
A deep foundation excavation was performed using earth retaining material on the lower extension of the old tower foot, including the removal of the old foundation. After the excavation was completed, a new foundation was installed and backfilled to the future ground, and the new foundation and old tower foot were mainly removed. After connecting with pillars and installing shoring to prevent buckling, load is applied to the main pillars with the temporary support materials removed, and the earth retaining materials and shoring are removed, and the main pillars are assembled sequentially until the new ground is reached. A method of connecting legs to existing steel towers by cutting and removing soil.