JP6876554B2 - Manholes and manhole rehabilitation methods - Google Patents

Description

The present invention relates to manholes and methods of rehabilitating manholes.

Conventionally, as shown in Patent Document 1 below, a tubular lower cylinder that is buried in the ground and extends in the vertical direction and an upper end opening that is arranged on the lower cylinder and opens to the ground are lids. A manhole with an upper cylinder, which is blocked by, is known. In this manhole, the upper cylinder is placed on the upper end opening edge of the lower cylinder.

Japanese Unexamined Patent Publication No. 2012-366555

However, in the conventional manhole, since the upper cylinder is directly placed on the upper end opening edge of the lower cylinder, the load applied to the upper cylinder from the ground is directly transmitted to the lower cylinder. , There was a concern about the durability of the lower cylinder.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a manhole capable of suppressing the load applied to the upper cylinder from the ground from being transmitted to the lower cylinder. To do.

In order to solve the above problems, the present invention proposes the following means.
The manhole according to the present invention is buried in the ground and has a tubular lower cylinder extending in the vertical direction and an upper end opening arranged on the lower cylinder and opening to the ground is closed by a lid. A manhole provided with an upper cylinder, which covers the inner peripheral surface of the lower cylinder and whose upper end protrudes upward from the lower cylinder, and a radial portion of the upper portion of the covering cylinder. The upper cylinder includes an intervening layer disposed on the outside and an annular pedestal placed on the upper surface of the intervening layer and surrounding the upper end portion of the covering cylinder from the outside in the radial direction, and the upper cylinder is the pedestal. It is characterized in that it is placed on the upper surface of the.

In this case, since an intervening layer is arranged between the upper end of the lower cylinder and the lower end of the upper cylinder, when a load is applied to the upper cylinder from the ground, this load is applied via the pedestal. It will be transmitted to the intervening layer. The presence of the intervening layer makes it possible to disperse or absorb the load, and prevent the load from being transmitted to the lower cylinder.

Further, since the inner peripheral surface of the lower cylinder is covered with the covering cylinder, it is possible to prevent the inner peripheral surface of the lower cylinder from coming into contact with the liquid or gas in the manhole, and the lower cylinder It is possible to prevent the inner peripheral surface of the manhole from corroding.
Further, since the upper end portion of the covering cylinder protrudes upward from the lower cylinder body and the intervening layer is arranged on the outer side in the radial direction in the upper portion thereof, the intervening layer is supported from the inner side in the radial direction by the covering cylinder. , It is possible to prevent the intervening layer from flowing into the inside of the lower cylinder from the upper end opening of the lower cylinder. Further, since the intervening layer is arranged on the outer side in the radial direction of the covering cylinder in this way, it is possible to prevent the liquid or gas in the manhole from coming into contact with the intervening layer.

A water blocking material having water expansion property may be arranged in the radial gap between the pedestal and the covering cylinder.

In this case, a water blocking material having water expansion property is arranged in the radial gap between the pedestal and the covering cylinder. Therefore, the water blocking material expands by containing water that has entered the radial gap from the inside of the covering cylinder and water that has entered the inside of the pedestal from the vertical or radial outside of the pedestal, and the pedestal. The water blocking material can exhibit sealing properties by being compressionally deformed in the radial direction between the inner peripheral surface of the coating cylinder and the outer peripheral surface of the covering cylinder. Therefore, it is not necessary to improve the dimensional accuracy of the inner diameter of the pedestal and the outer diameter of the covering cylinder.
Further, since the water blocking material is arranged in the radial gap between the pedestal and the covering cylinder, the pedestal and the covering cylinder are relatively displaced in the vertical direction due to the subsidence of the ground or the like. However, the water blocking material is not excessively compressed and deformed and crushed, and the sealing property of the water blocking material can be maintained.

Further, since the water blocking material exhibits a sealing property due to water expansion, even if the size of the radial gap between the pedestal and the covering cylinder varies depending on the position in the circumferential direction, the gap can be maintained. The expansion of the water blocking material enables reliable sealing. Thereby, the dimensions of the pedestal and the covering cylinder can be easily controlled.
Further, since the water blocking material is in contact with the inner peripheral surface of the pedestal and the outer peripheral surface of the covering cylinder without being adhered, for example, the water blocking material is in contact with the inner peripheral surface of the pedestal and the outer peripheral surface of the covering cylinder. Unlike the configuration that is adhered to the surface, even if vibration from the ground or shaking of an earthquake is applied to the water blocking material, the inner peripheral surface of the pedestal and the outer peripheral surface of the covering cylinder of the water blocking material It is possible to reliably seal the radial gap between the pedestal and the covering cylinder without peeling off the adhesive at the contact portion with the pedestal and creating a gap.

A vertical gap may be provided between the upper end of the covering cylinder and the lower end of the upper cylinder, and an elastically deformable sealing material may be disposed in the gap.

In this case, the vibration from the ground or the shaking of the earthquake is applied to the upper and lower cylinders, or the ground sinks, so that the upper and lower cylinders are relative in the vertical direction. Even when the position is displaced, the sealing material is elastically deformed following this displacement, so that the sealing property between the covering cylinder and the upper cylinder can be maintained.

The radial gap between the pedestal and the covering cylinder may be filled with a filling material.

In this case, since the filling material is filled in the radial gap between the pedestal and the covering cylinder, it is not necessary to increase the dimensional accuracy of the inner diameter of the pedestal and the outer diameter of the covering cylinder, and the pedestal and the covering cylinder are processed. Can be easily performed.

Further, in order to solve the above problems, the present invention proposes the following means.
In the method for rehabilitating a human hole according to the present invention, an upper cylinder in which the upper end opening opening to the ground is closed by a lid is buried in the ground and removed from the tubular lower cylinder extending in the vertical direction. A removal step, a covering step of covering the inner peripheral surface of the lower cylinder with a covering cylinder whose upper end portion protrudes upward from the lower cylinder, and an intervening layer arranged on the outer side in the radial direction in the upper part of the covering cylinder. A pedestal mounting step of placing an annular pedestal that surrounds the upper end portion of the covering cylinder from the outside in the radial direction on the upper surface of the intervening layer, and a pedestal mounting step of mounting the upper cylinder on the upper surface of the pedestal. It is characterized by comprising an upper cylinder mounting step of mounting a new upper cylinder having a length shorter than the body in the vertical direction.

In this case, since the upper end portion of the covering cylinder is projected from the lower cylinder during the coating step before the disposing step, the intervening layer is supported from the inside in the radial direction by the upper end portion of the covering cylinder during the disposing step. It becomes possible to do. Therefore, it is possible to prevent the intervening layer from flowing into the inside of the lower cylinder from the upper end opening of the lower cylinder, and the arrangement step can be easily performed.

At the time of the upper cylinder mounting step, a water blocking material having water expansion property may be arranged in the radial gap between the pedestal and the covering cylinder.
In this case, since the water blocking material arranged in the radial gap between the pedestal and the covering cylinder contains water, the water blocking material can exhibit the sealing property. Therefore, for example, the water blocking material can be used. Compared with a configuration in which the sealing property is exhibited by adhering to the inner peripheral surface of the pedestal and the outer peripheral surface of the covering cylinder, the water blocking material can be easily arranged.

At the time of the upper cylinder mounting step, the sealing material elastically deformable by the upper end opening edge of the covering cylinder and the new upper cylinder may be sandwiched in the vertical direction and compressed and deformed.

In this case, for example, after the sealing material is placed on the upper end opening edge of the covering cylinder, the upper cylinder is placed on the upper surface of the pedestal during the upper cylinder mounting step, so that the upper end opening edge and the upper cylinder of the covering cylinder are placed. With the body, the sealing material is compressed and deformed in the vertical direction, and the space between the upper end opening edge of the covering cylinder and the upper cylinder is sealed. As a result, for example, it is not necessary for an operator to enter the manhole and dispose of a sealing material between the upper end opening edge of the covering cylinder and the upper cylinder body, and the sealing work can be easily performed.

According to the present invention, it is possible to suppress the load applied to the upper cylinder from the ground from being transmitted to the lower cylinder.

It is a vertical sectional view of the manhole which concerns on 1st Embodiment of this invention. It is a figure which shows the state before mounting the upper cylinder body among the manholes shown in FIG. It is a figure which shows the modification of the manhole shown in FIG. It is a vertical sectional view of the manhole which concerns on 2nd Embodiment of this invention. It is a figure which shows the modification of the manhole shown in FIG. It is a figure which shows the other modification of the manhole shown in FIG.

(First Embodiment)
Hereinafter, the manhole 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
The manhole 1 is buried in the ground and has a tubular lower cylinder 10 extending in the vertical direction and an upper end opening which is arranged on the lower cylinder 10 and opens to the ground G by a lid (not shown). It includes an upper cylinder 20 to be closed.
In the following description, in a plan view from the vertical direction, the direction orthogonal to the central axis O at the upper end of the upper cylinder 20 is referred to as the radial direction, and the direction orbiting around the central axis O is referred to as the circumferential direction.

As shown in FIG. 1, the upper cylinder 20 has an annular top plate 21 in which the center of the inner peripheral surface is eccentric to one side in the radial direction with respect to the center of the outer peripheral surface in a vertical cross-sectional view, and a top. A tubular inclined wall portion 22 mounted on the upper surface of the plate 21 and having an upper end portion reduced in diameter from the lower end portion, an adjusting member 23 mounted on the upper end portion of the inclined wall portion 22, and an adjusting member 23. It is provided with a lid receiving frame 24 mounted on the top.
At the peripheral edge of the opening on the upper surface of the top plate 21, a recess 25 that is recessed downward and extends over the entire circumference is formed. The recess 25 opens inward in the radial direction. An intermediate slab 26 is installed in the recess 25.

The inclined wall portion 22 includes a lower wall portion 22A mounted on the top plate 21, an intermediate wall portion 22B mounted on the lower wall portion 22A, and an upper wall portion mounted on the intermediate wall portion 22B. It is equipped with 22C. In the illustrated example, the lower wall portion 22A, the intermediate wall portion 22B, and the upper wall portion 22C are formed separately and are fixed to each other by fixing members (not shown) arranged on the outer peripheral surface. .. The fixing method is not particularly limited. The lower wall portion 22A, the intermediate wall portion 22B, and the lower wall portion 22A may be integrally formed. These are made of mortar or concrete, but may be made of a composite material such as resin or FRP.

The center of the inner peripheral surface of the lower wall portion 22A is arranged coaxially with the center of the inner peripheral surface of the top plate 21. Further, the inner diameter of the lower wall portion 22A and the inner diameter of the top plate 21 coincide with each other. Therefore, the inner peripheral surfaces of the lower wall portion 22A and the top plate 21 are flush with each other in the vertical direction. The lower wall portion 22A has a cylindrical shape having the same outer diameter and inner diameter over the entire length in the vertical direction.
The outer diameter and inner diameter of the intermediate wall portion 22B are gradually reduced toward the upper side. In the illustrated example, the outer diameter and the inner diameter of the portion of the intermediate wall portion 22B located on the other side in the radial direction are gradually reduced toward the upper side. The intermediate wall portion 22B may have both sides in the radial direction gradually reduced in diameter toward the upper side, or may not be reduced in diameter and may have a cylindrical shape having the same diameter over the entire area in the vertical direction.

A recess 25 that is recessed downward and extends over the entire circumference is formed at the upper end opening edge of the intermediate wall portion 22B. The recess 25 opens inward in the radial direction. An intermediate slab can be installed in the recess 25.
The upper wall portion 22C is formed with the same outer diameter and inner diameter over the entire length in the vertical direction. A recess 25 that is recessed downward and extends over the entire circumference is formed at the upper end opening edge of the upper wall portion 22C. The recess 25 opens inward in the radial direction. An intermediate slab can be installed in the recess 25. The approximate height of the lid receiving frame 24 with respect to the ground G is adjusted according to the vertical size of the upper wall portion 22C.

The adjusting member 23 is a member for finely adjusting the height of the lid receiving frame 24 with respect to the ground G, and a plurality of adjusting members 23 are arranged at intervals in the circumferential direction. The outer surface of each of the plurality of adjusting members 23 facing outward in the radial direction and the inner surface facing inward in the radial direction are flush with the outer peripheral surface and the inner peripheral surface of the upper wall portion 22C, respectively.
The lid receiving frame 24 has a circular shape when viewed from above, and is arranged coaxially with the central axis O1. The inner peripheral surface of the lid receiving frame 24 and the inner surface of the adjusting member 23 are flush with each other. The upper end opening of the lid receiving frame 24 is open to the ground G. A lid accommodating portion 24A in which the lid body is accommodated is formed at the upper end opening edge of the lid receiving frame 24.

In the present embodiment, the manhole 1 covers the inner peripheral surface of the lower cylinder 10, and is arranged on the outer side in the radial direction of the upper portion of the covering cylinder 30 and the covering cylinder 30 whose upper end protrudes upward from the lower cylinder 10. It includes an intervening layer 40 provided, and an annular pedestal 50 that is placed on the upper surface of the intervening layer 40 and surrounds the upper end of the covering cylinder 30 from the outside in the radial direction. The covering cylinder 30, the intervening layer 40, and the pedestal 50 are arranged coaxially with each other.

The covering cylinder 30 is a cylindrical body made of, for example, a fiber reinforced resin such as FRP. The covering cylinder 30 is arranged coaxially with the lower cylinder body 10. The covering cylinder 30 is arranged with a gap in the radial direction from the inner peripheral surface of the lower cylinder body 10. The radial gap between the outer peripheral surface of the covering cylinder 30 and the inner peripheral surface of the lower cylinder 10 is filled with a filler 31 such as a mortar material. The covering cylinder 30 has the same outer diameter and inner diameter over the entire length in the vertical direction. The covering cylinder 30 is made of a material having excellent corrosion resistance.

The intervening layer 40 is formed to be fluid by earth and sand and crushed stone. In the illustrated example, the intervening layer 40 is formed into two layers in the vertical direction, the earth and sand layer 41 located on the lower side is formed integrally with the surrounding earth and sand, and the crushed stone layer 42 located on the upper side of the earth and sand layer 41 is formed. It is formed of crushed stone having a particle size larger than that of the earth and sand layer 41. The earth and sand layer 41 and the crushed stone layer 42 are in contact with the outer peripheral surface of the covering cylinder 30, respectively.

The earth and sand layer 41 and the crushed stone layer 42 are formed in a predetermined range around the covering cylinder 30 so as to cover the lower cylinder body 10 in a plan view from the vertical direction. In the illustrated example, the crushed stone layer 42 has a ring shape. The vertical thickness of the earth and sand layer 41 is larger than that of the crushed stone layer 42. The composition of the earth and sand layer 41 may be different from the composition of the surrounding earth and sand. In such a case, the earth and sand layer 41 may be formed in an annular shape having the same size as the crushed stone layer 42.
As described above, by disposing the intervening layer 40 with the material having a large particle size on the upper side, the load of the upper cylinder 20 is placed on the pedestal 50 as compared with the configuration in which the material having a small particle size is arranged on the upper side. The amount of sinking of the pedestal 50 can be suppressed when the load is applied.

The pedestal 50 is arranged coaxially with the covering cylinder 30. The pedestal 50 is placed on the upper surface of the crushed stone layer 42 of the intervening layers 40. The radial size of the pedestal 50 is smaller than that of the crushed stone layer 42. In other words, the outer peripheral surface of the pedestal 50 is located inside the outer peripheral surface of the crushed stone layer 42 in the radial direction. The inner diameter of the pedestal 50 is larger than the outer diameter of the covering cylinder 30, and has the same dimensions as the inner diameter of the lower cylinder 10.
The inner peripheral surface of the pedestal 50 faces the outer peripheral surface of the covering cylinder 30 with a gap in the radial direction. The upper end of the pedestal 50 projects upward from the upper end of the covering cylinder 30. The upper cylinder 20 is placed on the upper surface of the pedestal 50. In the illustrated example, the top plate 21 of the upper cylinder 20 is placed on the upper surface of the pedestal 50. The inner diameter of the pedestal 50 does not have to be the same as the inner diameter of the lower cylinder 10. In order to facilitate the positioning of the pedestal 50 and eliminate the possibility of interfering with the covering cylinder 30, it is preferable that the inner diameter of the pedestal 50 is the same as or larger than the inner diameter of the lower cylinder 10.

A vertical gap is provided between the upper end of the covering cylinder 30 and the lower end of the upper cylinder 20. In this gap, the elastically deformable sealing material 60 is arranged in a state of being compression-deformed in the vertical direction. The sealing material 60 is formed of a closed cell sponge 61 and an adhesive sealing member 62 (see FIG. 2) applied to the upper surface of the closed cell sponge 61. The lower surface of the closed cell sponge 61 is adhered to the upper end opening edge of the covering cylinder 30 with an adhesive. The seal member 62 is adhered to the lower surface of the top plate 21 of the upper cylinder 20.
The sealing material 60 may be, for example, a synthetic resin material or another material, or may be arranged in the gap without being compressed and deformed in the vertical direction.

As shown in FIG. 1, the gap in the radial direction between the pedestal 50 and the covering cylinder 30 is filled with the filling material 70. The filling material 70 is formed of, for example, a fast-curing mortar material. The filling material 70 has an annular shape arranged coaxially with the covering cylinder 30. The filling material 70 faces the lower surface of the top plate 21 with a gap in the vertical direction. The filling material 70 may be in contact with the lower surface of the top plate 21.

Next, a method of rehabilitating a manhole configured as described above will be described. As a method for rehabilitating a manhole according to the present embodiment, a tubular lower cylinder 10 that is buried in the ground and extends in the vertical direction, and an upper end opening that is arranged on the lower cylinder 10 and opens to the ground G. A method performed on an existing manhole provided with an upper cylinder (not shown) closed by a lid will be described.
The method for rehabilitating the human hole according to the present embodiment includes a removal step of removing the existing upper cylinder from above the lower cylinder 10, and an inner peripheral surface of the lower cylinder 10 from the lower cylinder 10 at the upper end. A coating step of covering with a covering cylinder 30 protruding upward, an arrangement step of arranging an intervening layer 40 on the outer side in the radial direction in the upper part of the covering cylinder 30, and an upper end portion of the covering cylinder 30 on the upper surface of the intervening layer 40. A pedestal mounting process for mounting an annular pedestal 50 that surrounds the pedestal 50 from the outside in the radial direction, and a new upper cylinder 20 having a length shorter in the vertical direction than the existing upper cylinder 50 on the upper surface of the pedestal 50. It is equipped with an upper cylinder mounting process for mounting.

In the removal process, first, the ground G around the existing manhole is excavated. At this time, as shown in FIG. 2, a range having a predetermined dimension wider than that of the lower cylinder 10 is excavated to the same height as the upper end opening edge of the lower cylinder 10 in a plan view seen from the vertical direction. Next, when removing the upper cylinder 20, after removing the lid from the upper cylinder 20, the lid receiving frame 24, the adjusting member 23, the inclined wall portion 22, and the top plate of the upper cylinder 20 are removed. 21 is removed in this order. In addition, a part or all of the upper cylinder 20 may be removed at once as one. Then, the inner peripheral surface of the lower cylinder 10 is washed with high pressure. In addition, the footrest hardware and the like attached to the inner peripheral surface of the lower cylinder 10 are removed.

In the coating step, first, the covering cylinder 30 is hung so as to be inserted into the lower cylinder body 10, and the covering cylinder 30 is supported and fixed at a predetermined position. At this time, the upper end portion of the covering cylinder 30 is projected upward from the lower cylinder 10 with a radial gap between the outer peripheral surface of the covering cylinder 30 and the inner peripheral surface of the lower cylinder 10. Next, the filler 31 is filled in the radial gap between the covering cylinder 30 and the lower cylinder 10. The filler 31 is filled so that the upper surface is flush with the upper end opening edge of the lower cylinder 10.

In the disposing step, first, as a backfilling operation of the earth and sand layer 41 in the intervening layer 40, the same earth and sand as the surroundings are backfilled in the area excavated in the removing step according to the height of the earth and sand layer 41. Next, crushed stone is arranged above the earth and sand layer 41 as an arrangement work of the crushed stone layer 42. At this time, the vertical thickness of the intervening layer 40 is set so that when the pedestal 50 is placed on the upper surface of the intervening layer 40, the pedestal 50 is 15 to 20 mm higher than the upper end opening edge of the covering cylinder 30. Is preferable.
In the pedestal mounting step, first, the pedestal 50 is mounted on the upper surface of the crushed stone layer 42 of the intervening layers 40. Next, the filling material 70 is filled in the radial gap between the inner peripheral surface of the pedestal 50 and the outer peripheral surface of the covering cylinder 30.

In the upper cylinder mounting step, first, an adhesive is applied to the lower surface of the closed cell sponge 61 in the sealing material 60, and then the closed cell sponge 61 is arranged over the entire circumference of the upper end opening edge of the covering cylinder 30. Next, the top plate 21 of the new upper cylinder 20 is placed on the upper surface of the pedestal 50. The vertical size of the new upper cylinder 20 is smaller than the existing upper cylinder by the same amount as the sum of the vertical sizes of the intervening layer 40 and the pedestal 50.
The closed cell sponge 61 may be adhered to the lower surface of the top plate 21 of the upper cylinder 20 by the sealing member 62, and then the top plate 21 may be placed on the upper surface of the pedestal 50.

In the present embodiment, the sealing material 60 is sandwiched in the vertical direction by the upper end opening edge of the covering cylinder 30 and the new upper cylinder 20, and is compressed and deformed. As a result, the closed cell sponge 61 is formed by the adhesive applied to the lower surface of the closed cell sponge 61 in the sealing material 60 and the adhesive sealing member 62, thereby forming the upper end opening edge of the covering cylinder 30 and the upper cylinder. It is crimped to the lower surface of the top plate 21 at No. 20.
After that, the inclined wall portion 22, the adjusting member 23, the lid receiving frame 24, and the lid body are placed on the top plate 21 in this order, and backfilling is performed to the ground G. Finally, by repairing the road surface of the ground G, the rehabilitation work of the manhole is completed. The adjusting member 23 may be a molded product such as a ring body, or may have a configuration in which mortar, concrete, or the like is piled up on the upper wall portion 22C and hardened at the construction site. The latter is preferable because it is easy to adjust the height on site.

As described above, according to the manhole 1 according to the present embodiment, since the intervening layer 40 is arranged between the upper end portion of the lower cylinder body 10 and the lower end portion of the upper cylinder body 20, the intervening layer 40 is arranged on the ground. When a load is applied to the upper cylinder 20 from the above, this load is transmitted to the intervening layer 40 via the pedestal 50. The presence of the intervening layer 40 makes it possible to disperse or absorb the load, and prevent the load from being transmitted to the lower cylinder 10.

Since the inner peripheral surface of the lower cylinder 10 is covered with the covering cylinder 30, it is possible to prevent the inner peripheral surface of the lower cylinder 10 from coming into contact with the liquid, gas, etc. in the manhole 1, and the lower part of the lower cylinder 10. It is possible to prevent the inner peripheral surface of the tubular body 10 from being corroded.
Further, since the upper end portion of the covering cylinder 30 projects upward from the lower cylinder body 10 and the intervening layer 40 is arranged on the outer side in the radial direction in the upper portion thereof, the intervening layer 40 is arranged from the inner side in the radial direction by the covering cylinder 30. It will be supported, and it is possible to prevent the intervening layer 40 from flowing into the inside of the lower cylinder 10 from the upper end opening of the lower cylinder 10. Further, since the intervening layer 40 is arranged on the outer side in the radial direction of the covering cylinder 30 in this way, it is possible to prevent the liquid or gas in the manhole 1 from coming into contact with the intervening layer 40.

A vertical gap is provided between the upper end of the covering cylinder 30 and the lower end of the upper cylinder 20, and the elastically deformable sealing material 60 is disposed in the gap. Vibration from the ground or shaking of an earthquake is applied to the upper cylinder 20 and the lower cylinder 10, or the ground sinks, so that the upper cylinder 20 and the lower cylinder 10 are relative in the vertical direction. Even when the position is displaced, the sealing material 60 is elastically deformed following this displacement, so that the sealing property between the covering cylinder 30 and the upper cylinder 20 can be maintained.

Since the filling material 70 is filled in the radial gap between the pedestal 50 and the covering cylinder 30, it is not necessary to increase the dimensional accuracy of the inner diameter of the pedestal 50 and the outer diameter of the covering cylinder 30, and the pedestal 50 And the covering cylinder 30 can be easily processed.
According to the method for rehabilitating a manhole according to the present embodiment, the upper end portion of the covering cylinder 30 is projected from the lower cylinder 10 during the coating step before the disposing step, so that the covering cylinder 30 is projected during the disposing step. The upper end of the intervening layer 40 can be supported from the inside in the radial direction. Therefore, it is possible to prevent the intervening layer 40 from flowing into the inside of the lower cylinder 10 from the upper end opening of the lower cylinder 10, and the arrangement step can be easily performed.

Further, during the upper cylinder mounting step, the sealing material 60 elastically deformable by the upper end opening edge of the covering cylinder 30 and the new upper cylinder 20 is sandwiched in the vertical direction and deformed by compression. Therefore, for example, the covering cylinder 30 After the sealing material 60 is placed on the upper end opening edge of the covering cylinder 30, the upper cylinder 20 is placed on the upper surface of the pedestal 50 during the upper cylinder mounting step, so that the upper end opening edge of the covering cylinder 30 and the upper cylinder 20 are placed. As a result, the sealing material 60 is compressed and deformed in the vertical direction, and the space between the upper end opening edge of the covering cylinder 30 and the upper cylinder 20 is sealed.
As a result, for example, it is not necessary for an operator to enter the manhole 1 and dispose of the sealing material 60 between the upper end opening edge of the covering cylinder 30 and the upper cylinder 20, and the sealing work can be easily performed. it can.

(Second Embodiment)
Hereinafter, the manhole 2 according to the second embodiment of the present invention will be described with reference to FIG.
In the present embodiment, the same components as the components in the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and only the differences will be described.

As shown in FIG. 4, in the manhole 2 according to the present embodiment, a water blocking material 80 having water expansion property is arranged in a radial gap between the pedestal 50 and the covering cylinder 30. .. As the water blocking material 80, a water-expandable sponge that expands when it contains water can be adopted. In the illustrated example, the water blocking material 80 is a water-expandable urethane foam.
The water blocking material 80 is arranged in a radial gap between the pedestal 50 and the covering cylinder 30 during the upper cylinder mounting process.

The water blocking material 80 is arranged on the inner peripheral surface of the pedestal 50 and the outer peripheral surface of the covering cylinder 30 without being adhered. In this way, since the water blocking material 80 is arranged in the radial gap between the pedestal 50 and the covering cylinder 30, in the manhole 2 according to the present embodiment, the upper end portion of the covering cylinder 30 and the upper end portion of the covering cylinder 30 The sealing material 60 is not arranged in the vertical gap between the lower end portion of the upper cylinder 20 and the upper cylinder 20.
Further, in the manhole 2 according to the present embodiment, the filling material 70 is not filled in the radial gap between the pedestal 50 and the covering cylinder 30.

As described above, according to the manhole 2 according to the present embodiment, the water blocking material 80 having water expansion property is arranged in the radial gap between the pedestal 50 and the covering cylinder 30. .. Therefore, the water blocking material 80 expands by containing water that has entered the radial gap from the inside of the covering cylinder 30 and water that has entered the inside of the pedestal 50 from the vertical or radial outside of the pedestal 50. The water blocking material 80 can exhibit sealing properties by being compression-deformed in the radial direction between the inner peripheral surface of the pedestal 50 and the outer peripheral surface of the covering cylinder 30. Therefore, it is not necessary to improve the dimensional accuracy of the inner diameter of the pedestal 50 and the outer diameter of the covering cylinder 30.
Further, since the water blocking material 80 is arranged in the radial gap between the pedestal 50 and the covering cylinder 30, the pedestal 50 and the covering cylinder 30 are relative to each other in the vertical direction due to the subsidence of the ground or the like. Even when the water blocking material 80 is displaced, the water blocking material 80 is not excessively compressed and deformed and crushed, and the sealing property of the water blocking material 80 can be reliably maintained.

Further, since the water blocking material 80 exhibits a sealing property due to water expansion, even if the size of the radial gap between the pedestal 50 and the covering cylinder 30 varies depending on the position in the circumferential direction. The gap can be reliably sealed by the expansion of the water blocking material 80. Thereby, the dimensions of the pedestal 50 and the covering cylinder 30 can be easily controlled.
Further, since the water blocking material 80 is in contact with the inner peripheral surface of the pedestal 50 and the outer peripheral surface of the covering cylinder 30 without being adhered, for example, the water blocking material 80 is in contact with the inner peripheral surface of the pedestal 50 and the inner peripheral surface of the pedestal 50. Unlike the configuration in which it is adhered to the outer peripheral surface of the covering cylinder 30, even if vibration from the ground or shaking of an earthquake is applied to the water blocking material 80, the inner circumference of the pedestal 50 of the water blocking material 80 The adhesive between the surface and the outer peripheral surface of the covering cylinder 30 is not peeled off to form a gap, and the radial gap between the pedestal 50 and the covering cylinder 30 can be reliably sealed. ..
Further, since the water blocking material 80 arranged in the radial gap between the pedestal 50 and the covering cylinder 30 contains water, the water blocking material 80 can exhibit the sealing property, for example, water blocking. The arrangement work of the water blocking material 80 can be easily performed as compared with the configuration in which the material 80 is adhered to the inner peripheral surface of the pedestal 50 and the outer peripheral surface of the covering cylinder 30 to exhibit the sealing property.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, as shown in FIG. 3, in the modified example of the manhole 1 according to the first embodiment, the upper cylinder 20 of the manhole 1B does not include the top plate 21. Further, the inclined wall portion 22 in the upper cylinder 20 does not include the lower wall portion 22A. By adopting such a configuration, the manhole 1 can be made compact in the vertical direction and the radial direction.

Further, as shown in FIGS. 5 and 6, in the modified example of the manhole 2 according to the second embodiment, there is a gap between the pedestal 50 and the covering cylinder 30 in the manholes 2B and 2C. The packing material 70 is filled. The filling material 70 is formed of, for example, a fast-curing mortar material. The filling material 70 has an annular shape arranged coaxially with the covering cylinder 30. The filling material 70 may be filled below the water blocking material 80 as shown in FIG. 5, or may be filled above the water blocking material 80 as shown in FIG.

Further, in each of the above embodiments, the recess 25 is formed in the peripheral edge of the opening on the upper surface of the top plate 21, and the intermediate slab 26 is installed in the recess 25, but the present invention is not limited to this aspect. It is not necessary to form the recess 25 in the top plate 21 and to install the intermediate slab 26.
Further, in each of the above embodiments, a vertical gap is provided between the upper end portion of the covering cylinder 30 and the lower end portion of the upper cylinder 20, and the elastically deformable sealing material 60 is formed in this gap. Although the arranged configuration is shown, the present invention is not limited to such an embodiment. The sealing material 60 may be arranged in a vertical gap between the upper end portion of the covering cylinder 30 and the lower end portion of the upper cylinder 20 without being compressed and deformed in the vertical direction. Further, the sealing material 60 does not have to be arranged in the gap.

Further, in the first embodiment, the structure is shown in which the filling material 70 is filled in the radial gap between the pedestal 50 and the covering cylinder 30, but the present invention is not limited to this aspect. The packing material 70 does not have to be filled in the radial gap between the pedestal 50 and the covering cylinder 30.

Further, in each of the above embodiments, as a method for rehabilitating a manhole, a method performed on an existing manhole provided with a lower cylinder body 10 and an upper cylinder body 20 has been described, but the method is limited to such a mode. I can't. As a method for rehabilitating a manhole, a covering cylinder 30 having an upper end projecting upward from the lower cylinder 10, an intervening layer 40 arranged on the outer side in the radial direction at the upper portion of the covering cylinder 30, and an upper surface of the intervening layer 40. It may be performed as a work of newly constructing a manhole 1 provided with a pedestal 50 mounted on the pedestal 50.
Further, in each of the above embodiments, as a method of rehabilitating the manhole, a method of reusing the existing lower cylinder 10 without removing it has been described, but the existing lower cylinder 10 is removed and a new lower cylinder 10 is removed. 10 may be installed. Even in this case, it is possible to suppress the load of the upper cylinder 20 from being transmitted to the lower cylinder 10. As a result, the durability of the lower cylinder 10 can be easily ensured. Further, by ensuring the durability of the lower cylinder 10, it is possible to suppress the burden of considering the strength deterioration of the lower cylinder 10, and the design becomes simpler.

In addition, it is possible to replace the components in the embodiment with well-known components as appropriate without departing from the spirit of the present invention, and the above-mentioned modifications may be appropriately combined.

1 Manhole 10 Lower cylinder 20 Upper cylinder 30 Covering cylinder 50 Pedestal 60 Sealing material 70 Filling material 80 Water blocking material

Claims (7)

A tubular lower cylinder that is buried in the ground and extends in the vertical direction,
A manhole comprising an upper cylinder arranged on the lower cylinder and having an upper end opening opened to the ground closed by a lid.
A covering cylinder that covers the inner peripheral surface of the lower cylinder and whose upper end protrudes upward from the lower cylinder.
An intervening layer arranged on the outer side in the radial direction at the upper part of the covering cylinder and on the upper side with respect to the upper end portion of the lower cylinder body.
It is placed on the upper surface of the intervening layer so that the intervening layer is disposed between the upper end portion of the lower cylinder body, surrounds the upper end portion of the covering cylinder from the outside in the radial direction, and has an inner diameter of the lower portion. With an annular pedestal equal to the inner diameter of the cylinder,
The upper cylinder is a manhole characterized in that it is placed on the upper surface of the pedestal. The manhole according to claim 1, wherein a water blocking material having water expansion property is disposed in a radial gap between the pedestal and the covering cylinder. A vertical gap is provided between the upper end portion of the covering cylinder and the lower end portion of the upper cylinder body.
The manhole according to claim 1, wherein an elastically deformable sealing material is disposed in the gap. The manhole according to any one of claims 1 to 3, wherein the radial gap between the pedestal and the covering cylinder is filled with a filling material. A removal process in which the upper cylinder whose upper end opening to the ground is closed by a lid is buried in the ground and removed from the top of the tubular lower cylinder extending in the vertical direction.
A coating step in which the inner peripheral surface of the lower cylinder is covered with a coating cylinder whose upper end portion projects upward from the lower cylinder.
An arrangement step of arranging an intervening layer on the outer side in the radial direction in the upper part of the covering cylinder and on the upper side with respect to the upper end portion of the lower cylinder body.
On the upper surface of the interposition layer, an annular pedestal having an inner diameter equal to the inner diameter of the lower cylinder while surrounding the upper end of the covering cylinder from the outside in the radial direction is interposed between the upper end of the lower cylinder. The pedestal mounting process in which the layers are placed so that the layers are arranged,
A method for rehabilitating a manhole, which comprises an upper cylinder mounting step of mounting a new upper cylinder having a length shorter in the vertical direction than the upper cylinder on the upper surface of the pedestal. The person according to claim 5, wherein a water blocking material having water expansion property is arranged in a radial gap between the pedestal and the covering cylinder during the upper cylinder mounting step. How to rehabilitate a hole. 5. The fifth aspect of the present invention is that, during the upper cylinder mounting step, a sealing material elastically deformable by the upper end opening edge of the covering cylinder and the new upper cylinder is sandwiched in the vertical direction and compressionally deformed. The method of rehabilitating a manhole described in.

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