JP4258012B2 - Seismic retrofitting method for existing manhole mounting pipes - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seismic retrofitting method for an existing manhole-attached pipe, which is mainly used as a sewer pipe and in which a gap is formed around the pipe for adding earthquake resistance to a joint between the manhole and the pipe.
[0002]
[Prior art]
In general, manholes are installed at a rate of one place every 30-50 m in sewer pipes, and the connection between the manhole and the buried pipe between the manholes penetrates the manhole wall larger than the outer shape of the pipe. A method of filling a gap between the outer peripheral surface of the tube body and the inner peripheral surface of the through hole with mortar, etc., and an end of the installed tube body, by opening a hole and inserting the end of the tube body into the through hole There is a method in which the parts are inserted into a mold for molding a manhole and are integrated with each other by molding the manhole with cast-in-place concrete.
[0003]
In addition, the manhole and the buried pipe move differently when an earthquake occurs, and a relative bending and axial expansion / contraction occur between them. In the existing manhole as described above, since the buried pipe body and the manhole wall are rigidly connected, a crack is generated at the joint portion between the two at the time of an earthquake, and it is sometimes destroyed.
[0004]
Therefore, in recent years, a flexible portion is installed at the end of the tube, and the expansion and contraction and bending generated at the end of the tube are absorbed by the flexible tube to provide earthquake resistance. ing.
[0005]
On the other hand, in existing manholes, the earth and sand outside the manholes are excavated for earthquake resistance, and a flexible material is installed at the joint between the manhole wall and the tube body, or a part of the buried tube body is formed by the flexible tube. The replacement work is designed to provide earthquake resistance.
[0006]
[Problems to be solved by the invention]
The conventional seismic retrofitting method for existing manhole mounting pipes as described above requires excavation and backfilling of the earth and sand at the manhole installation part, and also requires a large excavation hole due to the need for tube replacement. The cost was high, the construction period was inevitably long, and manholes were often installed on roads, which caused problems such as hindering traffic due to construction.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and has been made for the purpose of providing an earthquake resistant construction method for an existing manhole mounting tube that can be easily constructed at a low cost in a short period of time.
[0008]
[Means for Solving the Problems]
The feature of the invention described in claim 1 for solving the conventional problems as described above and achieving the intended purpose is that an existing manhole in which a pipe body for an existing water passage is integrated through a manhole wall. From the inside, a manhole wall around the tube body is used, and a concrete cutting device using a rotary tool integrally having a concrete cutting blade around the central axis is used, and the rotary tool is cut into the manhole wall and rotated. While moving along the circumference of the tube body, the tube body and the manhole wall are cut off in an annular arrangement having a constant width along the outer periphery of the tube body, and the tube body and the manhole wall are cut off. It is to fill an elastic sealing material capable of elastic deformation while maintaining water tightness.
[0009]
Further, the invention according to claim 2 is characterized in that the inner wall of the manhole wall around the tube body is formed from the existing manhole in which the existing water passage tube body is integrated through the manhole wall. By rotating a cylindrical core that is slightly larger than the outer diameter of the tube and having a diamond tip fixed to the tip, the tube and the manhole wall are cut off in an annular arrangement having a constant width along the outer periphery of the tube. In the seismic resistance construction method for an existing manhole mounting pipe rod, an annular sealing space formed by the excision is filled with an elastic sealing material capable of elastic deformation while maintaining watertightness.
[0010]
In the first and second aspects of the invention, it is preferable to use a water-swellable material as the elastic sealing material.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of a manhole in which the method of the present invention is applied. In the figure, 1 is an existing manhole, 2 is an existing pipe body that is integrated through the manhole wall 1a, 3 Is invert concrete placed at the bottom of the manhole.
[0012]
With respect to such an existing manhole mounting pipe rod, first, as shown in FIG. 2, in order to form a necessary work space in the manhole 1, the invert concrete 3 on the front surface of the end portion of the tube body 2 is only necessary. Remove.
[0013]
Next, as shown in FIG. 3, a manhole wall around the tube body 2 is cut out using a concrete cutter, and the manhole wall 1 a and the tube body 2 are cut off.
[0014]
By this excision, as shown in FIG. 4, an annular outer peripheral sealing material filling gap 4 is formed on the outer periphery of the tube body 2, and a new invert concrete 3 a is placed on the bottom of the manhole 1. At the time of this placement, as shown in FIG. 5, an end face side sealing material filling gap 5 is formed in a portion facing the end face of the tube body 2 in a continuous arrangement with the gap 4.
[0015]
The sealing material filling voids 4 and 5 on the outer periphery and the front face of the tube body 2 formed in this way are filled with an elastic sealing material 6 capable of elastic deformation while maintaining watertightness as shown in FIG. . As this sealing material, for example, a silicone resin or a water expansion rubber material containing a water absorbing material can be used.
[0016]
By filling the elastic sealing material 6 in this way, the tube body 2 and the manhole 1 are integrated via the elastic sealing material 6, and the relative movement between the two at the time of an earthquake is caused by the elastic sealing material 6. It will be allowed by deformation.
[0017]
The size of each of the gaps 4 and 5 is formed by the thickness of the elastic sealing material necessary to absorb the gap according to the expected magnitude of the relative motion during the earthquake.
[0018]
As an apparatus for forming the sealing material filling gap 4, a concrete cutting apparatus 10 as shown in FIGS. 7 and 8 is used as an example. In this apparatus, a ring-shaped revolving guide 12 is fixed to a support base 11 framed by a steel material, and a swivel base 13 is supported in the guide 12 so as to be capable of swiveling. The cutter drive motor 15 is supported on the swivel base 13 so as to be movable in the axial direction, and supported by the hydraulic cylinder 16 so as to be movable in the radial direction of the guide. An end mill cutter 18, that is, a rotary tool integrally having a concrete cutting blade around a central axis is fixed to a rotary drive shaft 15 a of the motor 15 via a chuck 17.
[0019]
Note that the end mill cutter 18 is one having a diamond tip fixed to the outer periphery.
[0020]
When using this device, use a hand-held drill to open an end mill cutter insertion hole in a part of the manhole wall around the tube body 2 in advance, disassemble and carry each part of the device into the manhole. The entire apparatus is assembled by aligning the center of the diversion guide 12 with the central axis of the tube body 2. In this state, the end mill cutter 18 is advanced in accordance with a previously opened insertion hole and inserted into the insertion hole. Next, the cutter drive motor 15 is driven to rotate the end mill cutter 18 while slowly rotating the swivel base 13, thereby moving the cutter 18 along the circumference of the tube body 2, and thereby sealing material in an annular arrangement. Filling voids 4 are formed.
[0021]
In addition, as shown in FIG. 9, instead of the end mill cutter 18 and its rotation driving motor 15, a jet water injection nozzle 20 for cutting concrete by spraying jet water is attached, and the swivel base is revolved. You may make it revolve along the circumference | surroundings of the pipe body 2 by injecting jet water, and thereby form the sealing material filling space | gap 4 in cyclic | annular arrangement | positioning.
[0022]
Further, as shown in FIG. 10, a core cutter 21 matched to the outer shape of the tube body 2 is pushed around the tube body 2 while being rotated by the drive motor 22, thereby forming a sealing material filling gap 4 in an annular arrangement. You may make it do.
[0023]
【The invention's effect】
As described above, in the construction method according to the present invention, the manhole wall around the pipe body extends along the outer periphery of the pipe body from the existing manhole where the pipe body for the water channel is integrated through the manhole wall. A rubber-like elastic sealing material that can be elastically deformed while maintaining watertightness is formed in the annular gap formed by the cutting by cutting the tube body and the manhole wall by cutting them into an annular arrangement having a constant width. By filling, the construction can be carried out by working from inside the manhole without excavating the surroundings of the manhole, and the construction does not become large-scale, making the existing pipes seismic resistant at low cost in a short period of time. Is possible.
[0024]
In addition, by using a rubber material having water expandability as the elastic sealing material, the rubber material is expanded by running water in the pipe or external ground water, and high watertightness can be maintained.
[0025]
Furthermore, a manhole is used by using a concrete cutter using a rotary tool integrally having a concrete cutting blade around the central axis, and moving the rotary tool through the manhole wall and rotating it around the tube body while rotating. By forming an annular gap in the wall, it is easy to carry in tools even in a narrow manhole, and the device can be used with simple and versatile tools such as an electric drill, so the workability is good and the device The cost required is reduced and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a manhole for constructing a method according to the present invention.
FIG. 2 is a partial cross-sectional view showing the inverted concrete in the method according to the present invention after being suspended.
FIG. 3 is a partial cutaway view showing a manhole wall excision process around the tubular body of the above.
FIG. 4 is a partial cross-sectional view showing a gap formation state by excision as above.
FIG. 5 is a partial cross-sectional view showing a state after the invert concrete is again placed.
FIG. 6 is a partial cross-sectional view showing a state after the sealing material is filled.
FIG. 7 is a sectional view of an example of an apparatus for carrying out the method of the present invention.
FIG. 8 is a front view of the above.
FIG. 9 is a cross-sectional view of another example of an apparatus for carrying out the method of the present invention.
FIG. 10 is a cross-sectional view of still another example of an apparatus for carrying out the method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Manhole 1a Manhole wall 2 Tubing body 3 Invert concrete 3a Invert concrete 4 Outer side sealing material filling space | gap 4a Insertion port 5 End surface side sealing material filling space | gap 6 Elastic sealing material 10 Concrete cutting device 11 Support stand 12 Revolving guide 13 Turning table 14 Rotation drive motor 15 Cutter drive motor 15a Rotation drive shaft 16 Hydraulic cylinder 17 Chuck 18 End mill cutter 20 Jet water jet nozzle 21 Core cutter 22 Drive motor

Claims (3)

A rotating tool having a manhole wall around the pipe body and a concrete cutting blade integrally around the central axis is used from within an existing manhole in which an existing water passage pipe body is integrated through the manhole wall . Using a concrete cutting device, the rotating tool is cut into a manhole wall and moved along the periphery of the tube while rotating to cut it into an annular arrangement with a constant width along the outer periphery of the tube. Seismic resistance of existing manhole mounting pipes, characterized in that the tubular body and the manhole wall are cut off, and the annular gap formed by the excision is filled with an elastic sealing material capable of elastic deformation while maintaining watertightness. Chemical method. The manhole wall around the tube body is slightly larger than the outer diameter of the tube body and the diamond tip is fixed to the tip of the existing manhole wall where the existing water passage tube body is integrated through the manhole wall. By rotating the cylindrical core, the tube and the manhole wall are cut off in an annular arrangement having a constant width along the outer periphery of the tube, and a watertight seal is formed in the annular gap formed by the cut. Seismic retrofitting method for existing manhole mounting pipes, which is filled with an elastic sealing material that can be elastically deformed while maintaining its properties .   The earthquake resistant construction method for existing manhole mounting pipes according to claim 1 or 2, wherein a material having water expandability is used as the elastic sealing material.

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