JP2001254376A - Method for repairing earthquake-resistant manhole joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of repair that saves the working labor in the work for replacement of an elastic body of an earthquake-resistant manhole joint, wherein an adhesive is contact-bonded only by disposing the elastic body coated with the adhesive at a prescribed place and which enables completion of the work without awaiting completion of the bonding. SOLUTION: A collar is connected to one end of an inner tube extension to the other end of which a sewer pipe is joined, through the intermediary of a cut-off ring, a sand intrusion preventing ring and a joint filling ring, and the other end of the collar is opened in the internal space of the manhole. Inside the end part on the manhole side of the collar, the belt-shaped elastic body is provided in the circumferential direction, almost in the shape of a semi- ring only on the lower side, and inverted in conformity with the inside diameter of the elastic body. In the repair of replacement of the elastic body of the earthquake-resistant manhole joint conducted in this way, support bars are provided at upper end parts on the opposite sides of the position of disposition of the elastic body, and a fresh elastic body being longer than a circular-arc length between the support bar on one side and the support bar on the other is fitted by insertion between these support bars.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing an earthquake-resistant manhole joint used for connecting a manhole to a sewer pipe.

[0002]

2. Description of the Related Art In a general manhole joint, when a sewer pipe moves and is pushed out into a manhole inner space at the time of an earthquake or the like, a joint connected to the sewer pipe is fixed to a manhole wall and connected to a joint body. An excessive load was applied, and the joint was sometimes damaged. The seismic manhole joint has an elastic body disposed at one end of the manhole joint, and absorbs a load on the joint caused by pushing out a sewer pipe by deformation of the elastic body.

[0003] However, a collar is connected to the other end of the short pipe having one end connected to the sewer pipe via a water stop ring, a sand biting prevention ring, and a joint filling ring, and the other end of the collar is opened to the inner space of the manhole. In the seismic manhole joint in which a band-shaped elastic body is provided on the inner surface of the collar at the manhole side end only in a semicircular shape only downward in the circumferential direction, and an invert corresponding to the inner surface of the elastic body is cast, In some cases, the deformed elastic body is deformed and protrudes into the sewage pipe, which may hinder the flow of sewage. In addition, after long-term use, the elastic body deteriorates due to damage caused by earth and sand or the like flowing down when mixed into the sewage or corrosion due to other dissolved substances or microorganisms. Therefore, after the occurrence of an earthquake or after a long period of time after the installation, the elastic body must be replaced and repaired.

In order to replace the elastic body, the old or damaged elastic body may be peeled off, and then a new elastic body may be attached. However, hydrogen sulfide gas, ammonia gas or other harmful gas is contained in the sewer pipe. Occurrences and anoxic conditions are often observed, and it is desired to complete the replacement work in as short a time as possible. On the other hand, the attachment of the elastic body is often performed using an adhesive, and the elastic body is used until the bonding is completed with any adhesive such as a solvent type, a water type, and a reactive type. There is a problem that it is necessary to keep pressing the collar, and it takes much time to complete the work.

[0005]

SUMMARY OF THE INVENTION The present invention saves labor for replacing an elastic body of an earthquake-resistant manhole joint, and only places an elastic body coated with an adhesive in a predetermined place.
An object of the present invention is to provide a repair method capable of completing the work without pressing the adhesive and waiting for the completion of the bonding.

[0006]

According to the present invention, there is provided a method for repairing an earthquake-resistant manhole joint, comprising the steps of: connecting a drain to one end of a short pipe;
It is connected via a sand biting prevention ring and a joint filling ring, and the other end of the collar is opened to a manhole internal space,
In the replacement and repair of the elastic body of the earthquake-resistant manhole joint, a belt-like elastic body is provided on the inner surface of the collar at the manhole side end in a substantially semicircular shape only downward in the circumferential direction, and an invert that matches the inner surface of the elastic body is cast. After the existing elastic member is removed, a support bar is provided at the upper end on both sides of the position of the elastic member, and an arc length between the one support bar and the other support bar is provided between the support bars. This is a method for repairing an earthquake-resistant manhole, which is characterized by inserting a new elastic body longer than that.

(Action) In the method for repairing an earthquake-resistant manhole joint according to the present invention, a support bar is provided at an end of an elastic body at a place where an elastic body is inserted, and one support bar and the other support bar are provided between the support bars. By inserting a new elastic body longer than the arc length between the bar and the elastic body, the elastic body is pressed and inserted between the support bars, and the elastic body itself acts to press itself against the collar. In addition, there is no need to perform pressure bonding until the bonding is completed. Therefore, the repair work is completed at the same time as the completion of the elastic body arrangement, and the work time is reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for repairing a seismic manhole joint according to the present invention will be described in detail with reference to the drawings.

FIG. 1 (a) is a partially cutaway sectional view of an earthquake-resistant manhole joint to which the present invention is applied, and FIG. 1 (b) is FIG. 1 (a).
FIG. 3 is a front view taken along line AA ′ of FIG. The seismic manhole joint 1 is connected to the collar 2 fixed through the manhole wall W, and the sewer pipe P is connected to the collar 2 via the water stop ring 31, the sand biting prevention ring 32, and the joint filling ring 33. The short tube 4 is inserted. The end of the short pipe 4 on the side of the manhole space M is arranged farther away from the end of the collar 2 than the end of the collar 2, and the elastic body 5 ′ is inserted into the inner surface of the collar 2 up to the end of the manhole and the invert 6 Is driven from the outside of the collar 2 to the arrangement height of the elastic body 5 ′ so that the inner diameter of the elastic body 5 ′ matches the inner diameter of the elastic body 5 ′. The driving height H of the invert 6 is usually such that the lower half of the collar 2 is buried, and the inner surface of the invert 6 has a curvature that matches the curvature of the collar 2 so that there is no step with the inner surface of the collar 2. Finished with a trowel, etc.

FIGS. 2 (a) to 2 (c) are diagrams for explaining the procedure of the repair work, and FIG.
(B) is a view showing a state in which the elastic body 5 'is peeled off and the support bar 7 is attached to the collar 2, and (c) is a view showing a state in which the new elastic body 5 is attached and repair is completed.

When replacing the elastic body 5 'due to aging or damage due to an earthquake or the like, first remove the aged elastic body 5' from the collar 2 and remove the remaining adhesive or the like from the collar 2 with a sander or the like. Then, the inner surface 21 of the collar 2 is smoothed. Next, the support bar 7 is fixed to one end in the collar 2 at a position where the new elastic body 5 is to be attached. The method of fixing the support bar 7 is not particularly limited. For example, an anchor nut may be driven into a collar, and the support bar 7 may be stopped by a bolt 71 or the like.

A support bar 7 'is similarly fixed to the other end of the collar 2 at the position where the new elastic body 5 is to be mounted. At this time, the distance between the support bar 7 and the other support bar 7 'along the arc on the inner surface of the collar 2 is shorter than the length of the elastic body 5 to be newly attached. That is, when the elastic body 5 is inserted between the two support bars 7 and 7 ', the elastic body 5 is contracted in the length direction, and is pressed against the inner surface of the collar 2 by its own repulsive force.

Therefore, the elastic body 5 must be able to be inserted between the support bars 7 and 7 'and firmly pressed against the collar 2, so that the elastic modulus of the elastic body 5 is generally 2.5 * 10 < ⁵ >
An elastic body in the range of 5 × 10 ⁵ Pa is preferably used. However, the compression modulus may be appropriately changed depending on the thickness of the elastic body 5 and the curvature of the collar 2, and is not particularly limited to the above range.

The material of the elastic body 5 satisfies the above-mentioned elastic modulus, withstands corrosion by harmful gas or microorganisms in the sewer pipe P, or damage due to contaminants such as sand, and does not cause dimensional change with time. For this purpose, for example, as an example, a plate-like body obtained by cutting a belt-like body made of synthetic rubber such as CR into an appropriate length is suitably used.

The size of the elastic body 5 is sufficient if elasticity suitable for the size of the portion to be repaired can be ensured and the surface of the sewer pipe P of the repaired elastic body 5 does not step with the inner surface of the collar 2. According to the inner diameter of the collar 2 and the elastic modulus of the elastic body 5, it may be used after being appropriately cut to an appropriate length. Generally, the thickness of the elastic body 5 is at most 30 mm or less,
In the range of the elastic modulus described above, the length of the elastic body 5 is 1.005 to 1.1.5 of the length along the arc between the support bars 7 and 7 ′.
05, more preferably 1.01 to 1.03 times. When the inner diameter of the collar 2 is large, the magnification of the elastic body 5 is large because the thickness of the elastic body 5 is large, and when the diameter of the collar 2 is small, the magnification may be large. If the magnification is too large, it may not be possible to insert between the support bars 7, 7 '. For example, as an example of implementation, when an elastic body made of CR rubber is applied to a collar having an inner diameter of 1500 mm, a repair portion having a width of 300 mm and a length of 2516 mm has a thickness of 52 mm.
Repaired as 2592 mm long.

The newly attached elastic body 5 is bonded to the collar 2 by applying an adhesive. The type of the adhesive is not particularly limited as long as it adheres to the elastic body 5 and the collar 2. However, since the work is performed in a sewer sewer, it is generally better to avoid using a solvent-type adhesive. It is desirable in terms of safety and worker health. That is, in addition to the water emulsion adhesive, a reactive adhesive such as an epoxy adhesive is preferably used.

For example, the elastic member 5 can be inserted by attaching the ends of the elastic member 5 coated with an adhesive to both the support bars 7 and 7 ', and the old elastic member 5' is inserted from the end side. It is only necessary to insert and push in the space 21 after being removed, but it is needless to say that this procedure does not always have to be performed.

When the elastic body 5 to which the adhesive is applied is pushed between the support bars 7 and 7 'on both sides, the repair work is completed without waiting for the adhesive to solidify. However, the use of sewer sewers after repair is not performed immediately after the work is completed, but if possible, it is better to wait for the adhesive to completely solidify before starting water flow, so adhesion will be more reliable. It is desirable to use an adhesive that cures and bonds even in a water atmosphere (for example, trade name “Joyner W”, manufactured by Sekisui Chemical Co., Ltd .;
In the case of using an epoxy-based adhesive), this is not particularly limited.

[0019]

According to the method for repairing the earthquake-resistant manhole joint 1 of the present invention, the support bar 7 is attached to the end of the elastic body at the place where the elastic body 5 is mounted.
7 'is provided, and a new elastic body 5 longer than the arc length between one support bar 7 and the other support bar 7' is attached, whereby the elastic body 5 is pressed into the space between the support bars 7, 7 '. Since the elastic body 5 itself is pressed against the collar 2 by the elasticity of the elastic body 5 itself, it is not necessary to particularly perform pressure bonding until the bonding is completed. Accordingly, the repair work is completed at the same time when the arrangement of the elastic body 5 is completed, and the work time is reduced.

[Brief description of the drawings]

FIG. 1A is a partially broken sectional view of an earthquake-resistant manhole joint to which the present invention is applied. (B) It is a front view along the AA 'line of FIG.1 (a).

FIG. 2A is a diagram showing a state before construction. (B) It is the figure which peeled off the elastic body and attached the support bar to the collar. (C) A view in which a new elastic body has been attached and repair has been completed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seismic manhole joint 2 Collar 21 Collar inner surface from which aging elastic body was removed 31 Water stop ring 32 Sand biting prevention ring 33 Joint filling ring 4 Short pipe 5 'Aging elastic body 5 New elastic body 6 Invert 7 Support bar 71 Bolt P Sewer pipe W Manhole wall M Manhole space

Claims (1)

[Claims] 1. A collar connected to the other end of a short pipe having one end connected to a sewer pipe through a water stop ring, a sand biting prevention ring, and a joint filling ring, and the other end of the collar being opened to a space inside the manhole. A belt-shaped elastic body is provided on the inner surface of the end of the collar on the manhole side in a substantially semicircular shape only downward in the circumferential direction, and the elastic body of the earthquake-resistant manhole joint is replaced with an invert corresponding to the inner surface of the elastic body. In the repair, after removing the existing elastic body, a support bar is provided at the upper end on both sides of the position where the elastic body is disposed, and between the support bars, between the one support bar and the other support bar. A method for repairing an earthquake-resistant manhole, which comprises inserting a new elastic body longer than an arc length.