JPS63228908A - Underground installation of cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a construction method for laying cables such as power lines and telephone lines underground.

b. Prior Art Traditionally, cab boxes have been used for wiring cables such as power lines and telephone lines, and the cables are laid by burying the cab boxes underground.

In this method using a cab box, for example, a U-shaped groove with a flat bottom is installed underground, the upper part of which is covered with a lid, and then the cable is pulled in through an opening at one end.

Problems to be solved by the invention However, the disadvantage is that the cable is easily damaged because the cable is pulled. In addition, conventional cab boxes often have a structure in which multiple box culverts are simply arranged in series and the lid is placed on top of a concrete U-shaped groove, so it is difficult to connect each member in the longitudinal direction. The connection and fixation of the upper and lower parts is incomplete. As a result, the overall strength of the cab box is weakened, and there is a risk that the upper road surface may deform due to traffic conditions. In addition, the bottom of the cab box was flat, which caused water to accumulate.

In addition, with conventional methods, if there is an obstacle such as a utility pole in the cable installation route, the cable cannot be laid unless the utility pole is relocated and temporarily installed. This not only increases the amount of on-site work, but also requires time and effort to set up the work, leading to problems such as lengthening the construction period.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide an underground cable laying method that can solve the above-mentioned problems, improve work efficiency, and shorten the construction period. It's about doing.

d6 Means for Solving Problems In order to solve the problems of the above-mentioned prior art, in the present invention, when a cab box is used to lay a cable underground on a route that has obstacles, the cab box A plurality of box culverts that can be divided into upper and lower parts are provided, and first, the lower half of the box culvert is connected over a predetermined distance except for the area where the obstacle is located, and these are fastened together with PC steel rods. U
A U-shaped groove is formed, and then a cable is laid by falling into this U-shaped groove over a predetermined distance, while the above-mentioned obstacle is removed, and the cable at the location where the obstacle was is lifted and held, and in this state, at least The bottom of the structure with one side wall open is placed below the cable and inserted between the existing box culverts, and another structure is integrally attached to the open part of the structure to connect the box culvert. These structures are fastened to the lower half of the adjacent box culvert by PC steel rods, and then the suspended cables are lowered into the structure while the lower half of the box culvert is The upper half of the box culvert is placed on each of the box culvert and the structure, and the two are connected by a connector, and then the upper halves of the box culvert are connected in the installation direction using PC steel rods.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

Figures 1 to 10 show an embodiment of the present invention, and in the figures, 1 is an assembled box culvert;
By connecting a plurality of box culverts 1 to each other, a cab box for storing cables, which will be described later, is constructed. As shown in FIGS. 1 and 2, the box culvert 1 consists of a box body 2 and a top plate portion 3 disposed on the top of the body 2.

The box main body 2 has a substantially U-shaped cross section, and includes a bottom portion 4 and side walls 5°6 provided on both sides of the bottom portion 4. A groove 8 formed along the longitudinal direction and a drain hole 9 communicating with the outside from the groove 8 are provided, thereby removing water, dirt, etc. that have entered the box body 2. Note that the drain hole 9 is provided as necessary.

Connecting fittings 10 are provided on both side walls 5 and 6 of the box body 2 to connect it to the adjacent box body.
During construction, the end of a PC steel rod 12 passing through the side wall in the longitudinal direction is guided into the box 11 as shown in FIG. It is designed to tighten. Further, at the upper ends of both side walls 5 and 6, a plurality of fastening fittings 15 for locking the top plate portion 3 are arranged at appropriate intervals in the longitudinal direction. The fastening fitting 15 is attached to the side walls 5 and 6 as shown in FIG.
It is implanted in a recess 16 perpendicular to the longitudinal direction, and is fastened to a fastening fitting of the overprint section 3, which will be described later, using a high-tensile bolt 17 and a nut 18.

On the other hand, the reprint section 3 includes a top part 19 and side walls 20 and 21 extending downward from both sides of the top part 19. 22 are provided near both ends of the top portion 19. Further, on the lower side of both side walls 20.21, fastening fittings 23 similar to the fastening fittings 15 provided on the box main body 2 are installed in the recesses 24, and correspond to the fastening fittings 15 on the box main body 2, respectively. Multiple units are installed.

In addition, in Fig. 1, 25.26 is a groove for pasting a sealant, 27.28.29 is a groove for a joint, and 25.26 is a groove for pasting a sealant.
A sealing material is applied to the grooves 27, 28, and 29, and a joint material is filled in the grooves 27, 28, and 29. A complete water-stopping structure is achieved by using these sealing materials and by using a connection method using PC steel rods or the like.

FIGS. 5 and 6 show another box culvert 30 used for branching and guiding cables (to be described later) inside and outside the cab box. This box culvert 30 includes a box body 31 and a It consists of a reprint part 33 that is placed and assembled leaving a rectangular opening 32 near one end surface.

The box body 31 includes a bottom portion 34 and side walls 35 and 36 provided on both sides of the bottom portion 34.
5.36 has a fastening fitting 37.38 on the end face on the opening 32 side.
are planted above and below. In addition, a plurality of knockouts 39, 40, 41 formed thinner than the wall thickness are arranged on both side walls 35, 36 so that they can be opened as necessary, and these knockouts are opened at the time of branching to open the power line. Cables such as telephone lines are guided outside the cab box. And the box body 3 facing the reprint section 33
Similar to the box body 2 shown in FIGS. 1 and 2, a plurality of fastening fittings 42 are disposed at appropriate intervals at the upper end of the side wall of the opening portion of the box 1.

Other configurations of the box body 31 and reprint section 33
The structure is the same as that of the box main body 2 and the reprint section 3. In addition, in FIGS. 5 and 6, 43 and 44 are connecting fittings similar to those provided in the box main body 2 and the reprinting section 3, and 45 is a tightening fitting installed in the reprinting section 33,
The fastening fittings 45 are arranged in correspondence with the fastening fittings 42 of the box body 31.

Figures 7 and 8 show a pair of structures 46 and 47 that will be constructed in the area where an obstacle such as utility pole A has been removed, and structures 46 and 47 have the same L-shaped cross section. It is formed. In other words, even if the cable 48 is already installed inside the box bodies 2 and 31, the structures 46 and 47 can be inserted between the existing box bodies 2 by holding the cable 48 in a suspended state using an H steel or the like. It is now possible to do so. Thus, the structures 46, 47 have their bottom parts 49, 50 abutted against each other, side walls 51, 52 facing each other, and PC steel rods 5 for horizontal tightening arranged in the middle direction.
3, the two are tensioned and integrated to form the same shape as the box body 1. Integrated construction 4
6.47 bottom 49.50 joint has urethane joint 54
is filled. In addition, as a means for integrating the structures 46 and 47, other than the PC steel rod 53, high-tensile bolts, adhesives, etc. may be used.

Moreover, a reprint part 55 similar to the reprint part 3 assembled to the upper part of the box main body 1 is placed on the upper part of the integrated structure 46, 47, and is fastened thereto. The integrated construction 46, 47 and the reprint section 55
The other configurations are the same as those of the box main body 2 and the reprint section 3. The structures 46 and 47 are provided with connecting fittings 56 and clamping fittings 57 similar to those of the box body 2, and the reprinting section 55 is provided with a connecting fitting 58 and a tightening fitting 59 similar to those of the reprinting section 3. are arranged respectively.

Next, the construction procedure will be explained. As shown in Figure 9,
After setting the foundation part M on which the cab box will be laid,
On this foundation part M, a large number of box bodies 2 are installed horizontally except for the installation location of the utility pole A, and the cable 48
A pair of box bodies 31 equipped with knockouts are arranged at locations where the inside and outside of the cab box are branched and guided. At this time, the pox body 31 is provided with the end surfaces of the openings 32 facing each other.

Next, a PC wire rod 12 is passed through each box body, and the PC wire rod 12 is tightened by a connecting fitting 10.43 provided on each box body to firmly connect each box body. In addition, at the portion where the box bodies 31 with knockouts are butted together, both box bodies 31 are firmly fixed by means of fastening fittings 37 and 38 provided on the opposing side wall end faces via high-tensile bolts and NANDs. Also, leave the knockouts open only where necessary.

In this way, a large number of box bodies are laid over a predetermined section, and each box body is firmly connected to form a U-shaped groove having an integral structure with an open upper part.

Next, a predetermined cable 48 is dropped from one side over the entire length of this U-shaped groove.

After laying the cable 48 over a predetermined length, the utility pole A is removed. Then, in order to construct structures 46 and 47 in the place where utility pole A was removed, as shown in Figure 7,
The cable 48 at this location is lifted and held by appropriate means. In this state, the bottom part 49 of the structure 46 is placed below the cable 48, and is laterally inserted between the existing box bodies 2 as shown in FIG. Also, the bottom 50 of the structure 47
is similarly placed below the cable 48 and inserted between the existing box bodies 2, with the bottom 50 butted against the bottom 49 of the structure 46.

Subsequently, the PC steel rods 53 are passed through the bottoms 49.50 of the constructs 46, 47, and the constructs 46, 47 are connected to each other by the PC steel rods 53.
It is tensioned and integrated by a steel rod 53, and both bottom parts 4
9. Fill the 50 joints with urethane joint 54. Then, the PC steel rods 12 are passed through each of the box bodies 2 adjacent to the structures 46 and 47, and similarly to the method described above, the PC steel rods 12 are tightened by the connecting fittings 10 and 56 to firmly connect the two. After that, the cable 48 was lifted up.
into construct 46.47.

Next, the top plate part 3 is placed on the box main body 2 located at the extreme end, and the corresponding fastening fittings 15 and 23 are tightened and fixed using the high tension ports 17 and nuts 18 (see FIG. 2). Next, another top plate part 3 is placed on the adjacent box body 2.
is placed and fixed by tightening with the fastening fittings 15 and 23, and the top plate portion 3 is set in the same manner. Then, the top plate part 33 is placed on the box main body 31 portion provided with the knockout, and is tightened and fixed in the same manner using the fastening fittings 42 and 45 (see FIG. 6).

In addition, a top plate portion 55 is placed on the 46 and 47 portions of the structure,
Tighten and secure in the same manner using the tightening fittings 57 and 59 (
(See Figure 8).

In this way, each top plate part 3, 33.55 connected on each box body 2.31 and construction 46.47,
The PC steel rods 12 passing through these top plates are tightened and fixed at the respective connecting fittings 22, 44, and 58. Note that a sealing material is provided in the grooves 25 and 26 prior to connection of each box main body and structure to each top plate portion.

After the tightening is completed, the joints such as the grooves 27.28.degree. 29 between each box body, structure, and top plate are filled with a joint material. Although not shown, an appropriate frame is installed around the opening 32 of the box main body 31, which opens at the top, on site, and a lid is placed over this so that workers can enter and exit from the box. Configure it so that you can.

In this way, the cable 48 is taken out to the outside of the cab box through the open knockout of the box body 31, and
Just guide them to the connection destination.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications and changes can be made based on the technical idea of the present invention.

For example, the structures 46 and 47 in the above-mentioned embodiments have a short projecting length of the bottom portion 49 and 50 and are formed in a shape of a letter I, but as shown in FIG. Alternatively, it may be formed in substantially the same shape as the box body 2 without the box body 6, and the other structure 61 may be formed in substantially the same shape as the side wall 5 or 6 of the box body 2. In addition, a structure consisting only of the bottom 4 of the box body 2 was first installed at the location where the utility pole A was removed, and then a structure forming the both side walls 5.6 was installed at the bottom 4.
May be connected to In short, it is sufficient that the shape of the structure is such that the construction can be carried out at the location where the utility pole A has been removed, with the installed cable 48 suspended.

e9 Effects of the Invention As mentioned above, the underground cable laying method according to the present invention is as follows:
After the cable is laid in the U-shaped groove of the box car heart, the obstruction is removed, and a specially shaped structure is inserted into the area where the obstruction was. There is no need to temporarily relocate utility poles, etc. along the cable installation route, and cables can be easily installed even in areas with obstacles. Therefore, compared to conventional methods, this method has excellent workability and requires less on-site work, so the construction period can be shortened and it is economically extremely advantageous.

In addition, by creating a strong connection structure using bolts, PC steel rods, etc. to connect each box body, structure, and each top plate in the upper and lower directions and in the installation direction, the cab box that stores the cables is integrated, making it possible to increase the height. A strong product can be obtained, and a cab box with an earthquake-resistant structure that can prevent displacement in the vertical direction and in the installation direction can be obtained.

[Brief explanation of the drawing]

Figures 1 to 10 show an embodiment of the underground cable laying method according to the present invention. Figure 1 is a front view of a box culvert that constitutes a cab box used in the method of the present invention, The figures are the same side view, Figure 3 is an enlarged explanatory view of the connecting fittings, Figure 4 is an enlarged explanatory view of the tightening fittings, Figure 5 is a front view of the opening side of the box culvert used as a cable branch point, Figure 6 is a side view of the same, Figure 7 is an explanatory diagram of the structure to be constructed in the area where the utility pole has been removed, Figure 8 is a front view showing the assembled state of the structure, and Figures 9 and 10 are the construction instructions. FIG. 11 is a front view showing a modification of the structure in the above embodiment. 1.30...Box Calhart, 2.31...Box body, 3.33.54...Top plate part, 10, 43.56...Connecting fittings, 12...PC steel bar, 15 , 42.57... Tightening fitting, 22, 44.58... Connecting fitting, D 23, 45.59... Tightening fitting, 37, 38... Tightening fitting, 46, 47.60 .61...Construction, 48...Cable, 53...PC steel bar. Figure 1 Figure 3 Figure 4

Claims (1)

[Scope of Claims] When a cab box is used to lay a cable underground on a route with obstacles, a plurality of box culverts that can be divided into upper and lower sections forming the cab box are provided, and first, the box culvert is The lower half is connected over a predetermined distance except for the obstacles, and these are connected with PC steel rods to form a U.
A U-shaped groove is formed, and then a cable is laid by falling into this U-shaped groove over a predetermined distance, while the above-mentioned obstacle is removed, and the cable at the location where the obstacle was is lifted and held, and in this state, at least The bottom of the structure with one side wall open is placed below the cable and inserted between the existing box culverts, and another structure is integrally attached to the open part of the structure to connect the box culvert. These structures are fastened to the lower half of the adjacent box culvert by PC steel rods, and then the suspended cables are lowered into the structure while the lower half of the box culvert is The upper half of the box culvert is placed on the section and the structure, and the two are connected by a connecting tool, and then the upper halves of the box culvert are connected in the installation direction with PC steel rods. An underground cable laying method using a cab box.