JPH0458254B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for connecting a manhole or handhole (hereinafter collectively referred to as a manhole) and an underground conduit in cable conduit installation work for communication, electric power, etc. .

[Conventional technology]

Conventionally, when installing underground pipes, the manhole was first constructed, then the underground pipe work was carried out, and the connection between the manhole and the underground pipe was poured with concrete at the construction site, and waterproofing and connections were made. The common method was to do both at the same time.

As shown in FIG. 5, the pipe connection part 7 of the manhole 1 is normally formed in the shape of an open duct, and to connect with the pipe, first the pipe connection part 7 of the manhole 1 is constructed. In order to obtain sufficient connection strength, after inserting the underground pipe 8 and holding it using a spacer etc., laying foundation gravel 9 on the outside of the manhole 1 and assembling the forms 10 and 11. Concrete or mortar (hereinafter simply referred to as concrete) 12 is poured not only inside the pipe connection 7 but also outside the manhole 1, and after the concrete 12 hardens after a curing period of 1 to 3 days, Formwork 1
0 and 11 were removed and the surrounding area was backfilled.

[Problem that the invention seeks to solve]

The conventional technology described above requires formwork assembly, concrete mixing, and
It requires time and work such as pouring and curing, which increases construction costs and prolongs the construction period.There are problems in that it takes several days to restore the road, and there is a strong need to shorten the construction period due to traffic conditions. It is requested.

In order to solve these problems, we have proposed methods that include attaching short pipes to serve as pipe joints to manholes during factory production and transporting and installing them at the site, or providing several spare holes for conduit connections in the manholes and installing them at the site. Methods such as connecting pipes to the necessary locations are also being considered,
In the former case, the connection point of the pipe is unspecified, so make-to-stock production at the factory is not possible, and a curing period is also necessary at the factory, which poses a problem with delivery time. After inserting the pipe into the hole, it was extremely difficult to fill the gap with concrete or adhesive, making it easy for water to leak, and there were concerns about the strength of the pipe, resulting in insufficient construction reliability.

The present invention has been made in view of the above points,
The purpose of the present invention is to provide a method for connecting manholes and underground pipes that simplifies the work of connecting pipes to manholes, reduces construction costs and shortens the construction period, and ensures the reliability of the pipe connection.

[Means for solving problems]

In the present invention, at the stage of manufacturing a manhole in a factory, a blind hole-shaped conduit is formed on the side wall of the manhole with a tapered inner peripheral surface so as to widen toward the inner surface while leaving a thin wall portion on the outer surface side. A preliminary hole for connection is provided, a short pipe is used as a joint for connecting the underground pipe to the manhole, and the outer peripheral surface is tapered so as to inscribe the preliminary hole around the short pipe. A processing section is prepared in advance. Then, at the pipeline connection construction site, the thin-walled part of the manhole is removed by an appropriate method, and the tapered outer circumferential surface of the formed part of the short pipe is placed between the tapered inner circumferential surface of the opened preliminary hole and the tapered outer circumferential surface of the formed part of the short pipe. The short pipe is fitted with an adhesive interposed therebetween, and the short pipe is fixed to the manhole side wall by pressing outward from the inside of the manhole. In other words, in the past, only the pipe was inserted into the pipe connection part of the manhole or the preliminary hole, and the gap was later filled with concrete or adhesive. By inserting a molded part with a wedge-shaped cross section with a tapered outer peripheral surface into a preliminary hole together with a short tube, and adhesively fixing the tapered surfaces of the preliminary hole and the molded part to each other with adhesive applied to these tapered surfaces. , it is possible to complete the pipe connection work to the manhole in a short time, and to ensure sufficient connection strength and watertightness of the connection part.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a perspective view including a partial cross section of this embodiment. 1 is a concrete precast manhole, and shows part of the side wall connected to the pipeline. 2 is a short pipe used as a joint to connect the manhole and the external pipe line, and during construction, a vinyl pipe or the like is used that is long enough (for example, about 40 cm) to be inserted from the inside of the manhole into the preliminary hole described below. 3
4 is a molded part provided around the short pipe 2, and 4 is a preliminary hole for conduit connection provided in the side wall of the manhole 1.

FIG. 2 is a side sectional view of the short tube 2 having a molded portion 3, which includes the end of the short tube 2 to which the bell mouth 2a is attached, and has a wedge-shaped outer circumferential surface 3a. It is formed into a cross-sectional shape. As the material for the molded part 3, a material that has the mechanical strength and watertightness necessary for pipe connection and is castable, specifically concrete or a casting resin such as epoxy resin, is used.

FIG. 3 is a side sectional view of an unused reserve hole 4 for conduit connection provided in the manhole 1. The reserve hole 4 leaves a thin wall portion 5 on the outer surface of the manhole side wall so that it can be opened when necessary. It is formed in the shape of a blind hole that widens toward the inner surface, and has a tapered inner circumferential surface 4a that is enclosed by the tapered outer circumferential surface 3a of the molded portion 3. As shown in FIG. 1, an appropriate number of these preliminary holes 4 are provided at positions on the side wall of the manhole where conduit connections are expected.

FIG. 4 is a side sectional view showing a state in which the short pipe 2 is attached to the manhole 1 and connected to the pipe line.

The construction order is as follows: First, the thin-walled part 5 at the pipe connection point is broken down with a chisel or the like, the preliminary hole 4 is opened, and then the tapered outer circumferential surface 3a of the molded part 3 of the short pipe 2 to be attached is coated with epoxy. Alternatively, apply an adhesive 6 such as polyester, insert the short pipe 2 and the molded part 3 into the preliminary hole 4, and connect the tapered inner peripheral surface 4a of the preliminary hole 4 and the tapered outer peripheral surface of the molded part 3. Press the molded part 3 outward from the inside of the manhole 1 until the fitting surface 3a is tightly fitted.
The installation work is completed by gluing a and 4a and removing the protruding adhesive 6. At this time, the short pipe 2 and the external conduit may be connected at the same time.

The feature of this method is that there are 4 preliminary holes around the short pipe 2.
By providing the molded part 3 having the tapered outer peripheral surface 3a inscribed in the tapered inner peripheral surface 4a, the molded part 3 can be simply inserted by applying adhesive to the preliminary hole 4. , sufficient connection strength and watertightness are ensured, and if these mating surfaces 3
If the same operation is performed without tapering a and 4a, the adhesive will be scraped off the fitting surface during insertion, and the reliability of the adhesion will not be obtained.

Furthermore, as shown in the figure, a molded part 3 and a preliminary hole 4 are provided.
By providing the step portions 3b, 4b at corresponding positions, the molded portion 3 can be positioned more accurately with respect to the manhole wall surface due to the contact of the step portions 3b, 4b.

〔Effect of the invention〕

According to the present invention, the preliminary hole for pipe connection of the manhole and the molded part of the short pipe for pipe connection are both formed at the factory production stage, and the molded part of the short pipe for pipe connection is formed at the construction site. The short pipe for conduit connection can be installed in the manhole by simply applying adhesive and inserting it into the preliminary hole for conduit connection, so the road can be backfilled in the few hours it takes for the adhesive to harden. Furthermore, when the need for pipe expansion arises in the future, unused spare holes can be opened and used, thereby eliminating work such as crushing holes in manhole pipe extensions and pouring concrete. is no longer necessary, significantly shortening the construction period and reducing construction costs.

Furthermore, since the short pipes are installed at the construction site, precast manholes can be made to stock at the factory, and there are no problems with delivery times.

Moreover, as mentioned above, the manhole wall and the short pipe forming part are bonded together with their tapered surfaces.
It has the excellent advantage of providing sufficient connection strength and watertightness without scraping off the adhesive when inserting the short pipe, and ensuring construction reliability.

[Brief explanation of drawings]

Fig. 1 is a perspective view including a partial cross section of an embodiment of the present invention, Fig. 2 is a side sectional view of a short pipe for pipe connection and its molded part, and Fig. 3 is for pipe connection on the side wall of a manhole. Figure 4 is a side sectional view of the preliminary hole and thin-walled part. Figure 4 is a side sectional view showing the state of the pipe connection when the short pipe is attached to the manhole. Figure 5 is the side sectional view showing the state of the pipe connection using the conventional on-site concrete pouring method. FIG. DESCRIPTION OF SYMBOLS 1... Manhole, 2... Short pipe for conduit connection, 3... Molded part, 3a... Tapered outer circumferential surface, 4... Reserve hole for conduit connection, 4a... Tapered inner circumferential surface, 5... Thin wall part,
6...Adhesive.

Claims (1)

[Claims] 1. A blind hole-shaped preliminary hole for conduit connection is prepared in advance in the side wall of the manhole, with the inner circumferential surface tapered so as to leave a thin wall on the outer surface and widen toward the inner surface. A molded part with a tapered outer circumferential surface is provided in advance around the short pipe that will serve as a joint for connecting the pipe, so that it is inscribed in the preliminary hole, and when connecting the pipe, the thin walled part of the manhole is removed and opened. The tapered outer circumferential surface of the formed part of the short pipe is fitted to the tapered inner circumferential surface of the preliminary hole, with an adhesive inserted therebetween, and the short pipe is pushed outward from the inside of the manhole. A method of connecting a manhole and underground pipe that is fixed to the side wall of the manhole by pressing.