JP3968251B2 - Seismic retrofitting method for existing manhole connection pipes - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for repairing a connecting portion between a manhole and a pipe in an existing water conduit or the like to a connection structure capable of withstanding movement (extraction direction and thrusting direction) and bending during an earthquake.
[0002]
[Prior art]
In general, a manhole produced at a factory is installed at regular intervals (for example, about 30 to 50 m) in a sewer pipe, and the connection between the manhole and the pipe disposed between the manholes is made on the peripheral wall of the manhole. A hole with a diameter larger than the outer diameter of the pipe to be connected is established, the end of the pipe is inserted into the hole, and the mortar is filled in the gap between the outer peripheral surface of the pipe and the inner peripheral surface of the hole The end of the laid pipe body is inserted into a manhole molding formwork, and concrete is cast into the formwork to form a manhole, thereby connecting and integrating the pipe and the manhole. There is a way.
In any of the above methods, the connection between the manhole and the tube has a rigid structure.
[0003]
By the way, when an earthquake occurs, the sewer pipe also moves due to the vibration of the ground, but the manhole and the pipe move differently from each other, and they are relatively bent and pulled out in the axial direction. A rush occurs.
For this reason, in the existing pipe in which the manhole and the pipe body are rigidly connected, a crack occurs at the connection portion between the two at the time of an earthquake, and the pipe body may be broken in some cases.
[0004]
Therefore, in recent years, in the case of a newly installed sewer pipe, the manhole and the pipe are connected via a flexible joint, and when an earthquake occurs, bending occurs at the connecting portion between them, and the axial direction is pulled out and thrusted. Is absorbed by the flexible joint to provide earthquake resistance.
Japanese Patent Laid-Open No. 2001-40751 proposes a method of repairing the connecting portion between the manhole and the pipe body to an earthquake resistant structure in the existing sewer pipe.
[0005]
The seismic retrofitting method is based on the fact that the existing manhole wall is integrated through the manhole wall, and the manhole wall around the pipe body is formed in an annular shape with a constant width along the outer periphery of the tube body. The tube body and the manhole wall are cut off by arranging them in an arrangement, and the annular gap formed by the cutting is filled with an elastic sealing material that can be elastically deformed while maintaining watertightness.
In forming the annular gap, the invert concrete at the bottom of the manhole is removed to the extent necessary, and then a concrete cutting device is installed on the bottom of the manhole so that a constant width is provided along the outer periphery of the tubular body. It is cut out in an annular shape.
[0006]
[Problems to be solved by the invention]
The above-mentioned seismic retrofitting method makes use of the pipe inserted into the manhole wall as described above and destroys the manhole wall and the invert concrete at the bottom of the manhole. There are many ingots of concrete produced by hanging (breaking) walls and invert concrete, and there is the inconvenience that it can only be treated as industrial waste.
Also, the tube connected to the manhole often has defects or cracks in the vicinity of the insertion and fixing to the manhole wall (about 10 cm to 20 cm from the outer peripheral surface of the manhole wall), and the portion is cut off. Without making any changes, it is difficult to achieve stable seismic resistance because the elastic sealant is filled in the annular gap around the outer periphery of the pipe without making any changes. In addition, when the pipe is damaged outside the peripheral wall of the manhole, the above method cannot be performed.
[0007]
The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to repair the manhole wall and the invert by minimizing the amount of destruction and to expect stable earthquake resistance. It is to provide a method that can be used.
[0008]
[Means for Solving the Problems]
The technical means taken by the present invention in order to achieve the above object is a method of repairing an existing manhole connection pipe in which the pipe body constituting the pipe line is connected and fixed to the peripheral wall of the manhole with a rigid structure to an earthquake resistant structure. From the inside of the manhole, the cutting and removing step of cutting and removing the pipe connected to the peripheral wall of the manhole at a predetermined distance from the outer surface of the peripheral wall, and the tip of the pipe line remaining after cutting and removing the pipe, A tube mounting step of attaching and fixing one side portion of a flexible rubber tube that can be folded back by being pushed in the axial direction, and connecting a rigid sleeve to the other side portion of the rubber tube; and the rubber tube The sleeve connected to the sleeve is pushed into the hole opened in the peripheral wall in the tube cutting and removing step, and the sleeve is pushed concentrically in the hole, and the outer peripheral surface of the sleeve and the inner peripheral surface of the hole A sleeve fixing step of fixing the manhole wall sleeve by a gap filled with mortar of, characterized in that it consists of (claim 1).
[0009]
In the present invention, the pipe body constituting the pipe is rigidly connected and fixed to the peripheral wall of the manhole in the present invention is a factory-manufactured manhole constituent member is brought into the field, and the pipe body is inserted into the drilling hole of the constituent member. The shape of the assembly manhole for inserting and fixing the mortar between the outer periphery of the tube and the inner peripheral surface of the drilled hole, and the end of the laid tube are inserted into the mold for manhole molding, By molding concrete into the frame and molding the manhole, it is possible to cope with both forms of on-site manholes that connect and integrate pipes and manholes.
Therefore, in the case of the assembly manhole, the tube body cutting and removing step may be only the tube body, but the mortar that fixes the tube body to the drilling hole of the manhole may be removed together. In the case of a cast-in-place manhole, since it is fixed with concrete cast into the formwork, only the pipe body is removed by suspending, but a part of the concrete peripheral wall outside the tubular body is removed by suspending in consideration of later work efficiency. It is also good. In that case, when the sleeve is fixed by mortar filling, the above-mentioned suspended portion is also repaired at the same time.
Also, the cutting length of the tube in the above cutting and removing step is often the length of the tube that is broken or cracked in the vicinity of the connection with the manhole. It is about 10 cm to 20 cm from the outer surface.
Further, when an invert is installed at the bottom of the manhole, the invert related range necessary to hang the inside of the hole is removed.
The inner diameter of the sleeve connected to the rubber tube attached to the end of the pipe is approximately the same as the inner diameter of the pipe.
[0010]
Further, before the sleeve pushing step, a foam material is injected into the working space between the outer surface of the peripheral wall of the manhole and the outer surface of the tube and the rubber tube attached to the tube, and after the sleeve pushing step, injecting a foam material into compartmented space at the end of the folded in a U-shape rubber tube and the sleeve and the tube in the sleeve pushing step is suitable (claim 2).
Further, in the tube attaching step, sleeve, not fitted with cushioning material at its end facing the pipe body is connected to the other side of the rubber tube having an inner diameter and the inner diameter of the diameter of the tube Rukoto is suitable (claim 3).
The rigidity of the sleeve in the present invention means that the rubber tube is fixed to the sleeve with a tightening band, but the strength is not deformed or broken by the tightening force of the tightening band, and the sleeve is fixed to the peripheral wall of the manhole. For this reason, the mortar is filled between the hole inner surface of the manhole peripheral wall and the outer surface of the sleeve, which means a strength sufficient to prevent deformation and breakage due to the mortar filling.
[0011]
According to the means of claim 1, only the tube fixed to the peripheral wall of the manhole is removed for a predetermined length from the outer surface of the peripheral wall from the inside of the manhole, or the mortar for fixing the tube is suspended and removed if necessary, A portion of the tubular body fixed to the manhole is cut and removed, and a rigid sleeve is connected to the end of the remaining pipe line after cutting and removal through a flexible rubber tube, and the sleeve is connected to the hole of the manhole. Since it is fitted and fixed inside, the manhole itself is not destroyed, the amount of concrete lump to be removed is very small, and bending and movement due to ground fluctuation are reliably absorbed by the rubber tube.
In addition, the tube body to which the rubber tube is attached often has defects or cracks in the vicinity of the fixed part with the manhole, and the rubber tube is attached to the normal part by excising that part, so stable earthquake resistance is achieved. I can expect.
According to the second aspect, the inside and outside of the rubber tube can be protected with the foam material.
Further, according to the third aspect of the present invention, even if the tube body moves to the manhole side, since the buffer material is attached to the end portion of the sleeve, the tube body (fume tube) collides with the sleeve. Is also prevented from being damaged.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the earthquake resistance construction method according to the present invention will be described with reference to the drawings for the connection structure between the assembly manhole and the tubular body.
FIG. 1 is an explanatory view showing the steps of the seismic retrofitting method, (a) is a cross-sectional view showing a state (existing pipe) before constructing the seismic retrofitting method, and in the figure, 1 is a manhole on its peripheral wall 1a 2 is inserted, and a mortar 4 is filled between the inner surface of the drilling hole 3 and the outer peripheral surface of the tubular body 2 so that the manhole 1 and the tubular body 2 are connected and fixed in a rigid structure. .
[0013]
The work of refurbishing an existing pipe having the above structure into a seismic structure is composed of a connecting pipe cutting and removing process → tube mounting process → sleeve pushing process → sleeve fixing process.
In the cutting and removing step, as shown in FIG. 1B, the mortar 4 between the inner surface of the hole 3 and the outer peripheral surface of the tube body 2 is removed from the inside of the manhole 1 and from the inside of the tube body 2. The tube body 2 is cut or suspended from the outer surface of the peripheral wall of the manhole 1 at a predetermined distance. The tube 2 is cut at a position near the drilling hole 3 of the manhole 1 due to the vibration or the like of the ground until now. In many cases, the defective portion is removed, bent and moved. It is a position that secures a work space for attaching a rubber tube to cope with the above.
The work space is secured by removing the required area of the ground outside the manhole. At this time, if the ground is soft or has a lot of moisture, the ground is temporarily fixed to prevent the ground from collapsing, and the space is filled with a material that is not fixed after completion of the seismic operation described later, such as urethane foam. fill in.
Further, in relation to the removal of the mortar 4 from the suspension, a part of the invert 5 installed at the bottom of the manhole 1 is removed from the suspension. Further, the earth and sand around the cut pipe body 2 is removed to secure the work space X, and the next tube mounting step is started.
[0014]
As shown in FIG. 1 (c), the tube attachment process is performed by fitting and attaching one side portion 6a of a flexible rubber tube 6 to the end portion of the tube body 2 having a predetermined length cut and removed. The attached portion is fastened and fixed by the fastening band 7, and a sleeve 8 having rigidity is connected and fixed to the other side portion 6b of the rubber tube 6 by the fastening band 7 '.
The length of the rubber tube 6 attached to the tubular body 2 is set to a length (for example, about 30 cm) that can exhibit elasticity and flexibility that can satisfy the earthquake resistance standard (level 2 earthquake). Further, the shape of the rubber tube 6 is such that the outer diameter of the sleeve 8 is smaller than the outer diameter of the tube body 2 and the inner diameter is the same, so that the mounting side with the sleeve 8 is slightly smaller than the mounting side with the tube body 2. The taper tube formed in (1) is preferable because it can be fixed without generating wrinkles. Of course, straight tubes having the same inner diameter on both sides may be used.
[0015]
In addition, the sleeve 8 connected to the other side portion 6b of the rubber tube 6 in the tube mounting step is made of metal (for example, stainless steel) or other material having rigidity equivalent to that, and the sleeve 8 Is formed to have substantially the same width as the peripheral wall thickness of the manhole 1, whereby the sleeve 8 is firmly fixed to the peripheral wall of the manhole 1 in a subsequent sleeve fixing step.
[0016]
After completing the tube mounting process, the process proceeds to the next sleeve pushing process. Before that, urethane foam is formed in the work space X between the outer peripheral surface of the manhole 1 and the outer surface of the tube body 2 and the rubber tube 6 attached to the tube body 2. 9 is injected to protect the attachment portion between the tube body 2 and the rubber tube 6 (see FIG. 1D).
[0017]
After the work space X is filled with the urethane foam 9, the process proceeds to the sleeve pushing process. In this sleeve pushing step, as shown in FIG. 1 (e), the sleeve 8 connected to the rubber tube 6 is pushed into the hole 3, and the sleeve 3 is concentrically disposed within the hole 3. By pressing the sleeve 8, the rubber tube 6 connected to the tube body 2 and the sleeve 8 is folded back into a substantially U shape with the connecting and fixing portion with the sleeve 8 being folded back inside the tube 6.
Then, after the sleeve pushing process is completed, the process proceeds to the sleeve fixing process. Before that, the space (X ) defined by the rubber tube 6 and the sleeve 8 and the end of the tubular body 2 folded back in a substantially U shape in the sleeve pushing process. ') The urethane foam 9' is injected and filled in (see (e) of FIG. 1) . Thereby, the rubber tube 6 is protected from both inside and outside.
The injection process of the foamed urethane 9, 9 ′ performed before and after the above-described sleeve pushing process is not necessarily a necessary process, and can be arbitrarily selected. Also, the urethane foam 9, 9 ′ is injected using a gun-type filler or the like.
[0018]
After the sleeve 8 is pushed into a predetermined position in the hole 3, the sleeve fixing process is started.
In this sleeve fixing step, as shown in FIG. 1 (f), the gap between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the ground hole 3 is filled with mortar 10 to fix the sleeve 8 to the manhole peripheral wall 1a. The inner surface is finished so as to be flush with the inner surface of the peripheral wall of the manhole 1.
Further, in finishing with mortar, when a part of the invert 5 is removed by the first cutting and removing step, the invert is repaired by filling the suspended part with mortar.
[0019]
In the tube attaching step, the sleeve connected to the other side portion 6b of the rubber tube 6 is made of a material having rigidity. Therefore, when the tube body 2 moves to the manhole 1 side, the concrete collides with the sleeve 8 due to the collision. It is also conceivable that problems such as breakage of the end of the manufactured tube (fume tube) 2 may occur. In order to solve such a problem, the sleeve 8 having a cushioning material 11 attached to the end facing the tube body 2 can be used.
The cushioning material 11 is preferably a cylindrical body made of sheet rubber, and is fixed to the end of the sleeve 8 with a band.
[0020]
The pipe modified to the seismic structure by the above method is moved in the vertical direction with respect to the manhole or in the axial direction approaching or moving away from the manhole due to the vibration of the ground due to the earthquake motion. The rubber tube 6 responds flexibly to movement in the axial direction, and exhibits earthquake resistance (see FIGS. 2A and 2B).
[0021]
In the above-described embodiment, the pipe connected to the assembly manhole is made earthquake resistant. However, in the case of the pipe connected to the on-site manhole, the cutting and removing process of the pipe is fixed to the peripheral wall of the manhole. Only a part of the peripheral wall of the manhole on the outside of the tube may be suspended and removed in consideration of later workability. In that case, as a matter of course, the suspension range of the peripheral wall of the manhole is kept to the minimum necessary so as not to affect the strength of the manhole body.
[0022]
【The invention's effect】
The seismic retrofitting method for the existing manhole connecting pipe according to the present invention can perform the seismic retrofitting work without damaging the manhole (hole drilling) and the invert. And the concrete lump which arises in a cutting and removal process is very few compared with the conventional construction method (Unexamined-Japanese-Patent No. 2001-40751), processing of an industrial waste is unnecessary and can shorten a construction period.
In addition, the rubber tube is attached by cutting and removing the portion inserted and fixed to the peripheral wall of the manhole, so that the rubber tube can be attached to a normal portion free from defects and cracks, and thus a stable earthquake resistant structure can be established. . Moreover, even when the existing pipe is broken outside the peripheral wall of the manhole (position close to the peripheral wall), the present construction method can be applied.
In addition, the rubber tube can be protected from both the inside and outside directions, and stable earthquake resistance can be maintained over a long period of time.
Furthermore, according to the structure of Claim 3, even if a pipe body moves to the manhole side, it can prevent that this pipe | tube is damaged.
[Brief description of the drawings]
FIG. 1 is a process explanatory diagram showing a construction method according to the present invention.
FIG. 2 is a cross-sectional view showing the action of a rubber tube having an earthquake-resistant structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Manhole 1a ... Peripheral wall 2 of a manhole ... Pipe body 3 ... Drilling hole 4 ... Mortar 5 ... Invert 6 ... Rubber tube 8 ... Sleeve 9, 9 '... Foam material (urethane foam)
10 ... Mortar for fixing sleeve or invert 11 ... Buffer material

Claims (3)

A method of repairing an existing manhole connection pipe in which the pipe body (2) constituting the pipe line is connected to the peripheral wall of the manhole (1) with a rigid structure to a seismic structure,
Than the inner (a) the manhole (1), and cutting and removing step of cutting and removing at a position a predetermined distance connected the tube to the wall only (2) from the peripheral wall outer surface of the manhole (1),
(B) One side portion of a flexible rubber tube (6) that can be folded back by being pushed in the axial direction is attached and fixed to the tip of the remaining tube (2), and the rubber tube (6 A tube attachment step of connecting a sleeve (8) having rigidity to the other side portion;
(C) said sleeve (8) which is connected to the rubber tube (6), pushed into the tube removed drilling which opens in the circumferential wall in the step (3) in the drilling (3) in the sleeve (8) A sleeve pushing process to be arranged concentrically with
And (d) fixed to the outer peripheral surface and the peripheral wall of the boring (3) inner peripheral surface and filled to the sleeve mortar (10) in the gap (8) the manhole (1) of the sleeve (8) A sleeve fixing process;
A seismic retrofitting method for existing manhole connection pipes. Before the sleeve pushing step, the peripheral wall outer surface and the tube body of the manhole (1) (2) and tube body outer surface and the working space of the rubber tube attached to (2) (6) (X) injecting a foam material (9), after the end of the sleeve pushing step, the ends of the rubber tube (6) and the sleeve (8) and the tube body is folded into a substantially U-shape in the sleeve pushing step (2) in earthquake resistance method of the existing manhole connection tube according to claim 1, 'in the foam (9 space (X)' which is defined, characterized in that to inject). In the tube attaching step, said tube body (2) is a sleeve (8) which has an inner diameter and inside diameter identical are connected on the other side of the rubber tube (6) of the tube (2) The shockproofing method for an existing manhole connection pipe according to claim 1 or 2 , wherein a shock-absorbing material (11) is attached to opposite ends.

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