Hand Hole

Abstract

To improve an internal heat resistance of a hand hole in which a box body is constituted of a concrete frame body and a lid portion and a water pipe is disposed inside.SOLUTION: A hand hole (1) comprises: a concrete frame body (10) that constitutes a bottom portion (12) and a side portion (11); a lid portion (20) that closes an upper part of the frame body (10); a water pipe (40) arranged inside a box body constituted of the frame body (10) and the lid portion (20); and an inner lid (30) including a heat insulating material layer (31) placed below the lid portion (20) and spaced apart from the lid portion (20), and partitioning a space (S50) inside the box body into an upper space (S51) and a lower space (S52) including the water pipe (40).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to handholes. [Background technology]

[0002] Patent Document 1 discloses a handhole installed inside a tunnel. FIG. 5 is a cross-sectional view of handhole 107 disclosed in Patent Document 1. Handhole 107 is a concrete box covered with a steel plate lid 123. Inside handhole 107, water supply piping 105, steel pipe 115, piping joint 111, branch 109, etc. are arranged. In Patent Document 1, heat insulating material 125 is arranged on the underside of lid 123 to insulate the inside of the handhole from the heat inside the tunnel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-167510 Summary of the Invention [Problem to be solved by the invention]

[0004] At the scene of a fire inside a tunnel, temperatures can reach extremely high temperatures of 800 to 1200°C. In such cases, the steel plate that makes up the cover 123 can also reach extremely high temperatures. In the handhole of Patent Document 1, the inside can reach temperatures of 80°C or higher. In particular, when polyethylene piping is used as a water supply piping, a handhole with even better thermal insulation is required. [Means for solving the problem]

[0005] In order to solve the above problems, a handhole according to a first aspect is a box having a bottom, sides, and a lid, and a water supply pipe is housed inside the box. The handhole includes a concrete frame that forms the bottom and sides, the lid that closes the top of the frame, the water supply pipe that is placed inside the box formed by the frame and the lid, and an inner lid that is placed below the lid and spaced apart from the lid, and includes an insulating layer that separates the space inside the box into an upper space and a lower space that contains the water supply pipe.

[0006] The handhole of the second aspect is the handhole of the first aspect, wherein the lid portion comprises a metal plate and a metal handle attached to the metal plate, and the inner lid is positioned below the lowest part of the handle.

[0007] A handhole according to a third aspect is the handhole according to the second aspect, wherein the distance between the metal plate and the inner cover is 80 mm or more.

[0008] A handhole according to a fourth aspect is the handhole according to any one of the first to third aspects, wherein the heat insulating material layer has rock wool.

[0009] A handhole of a fifth aspect is the handhole of any one of the first to fourth aspects, wherein the inner cover further has a holding portion below the heat insulating layer that holds the heat insulating layer.

[0010] A sixth aspect of the present invention is a handhole according to any one of the first to fifth aspects, wherein the handholes are disposed at predetermined intervals underground under a tunnel. [Effects of the Invention]

[0011] The handhole of the present disclosure has an insulating layer disposed below the lid at a distance from the lid. The air layer below the lid and the insulating layer act as an insulating layer, allowing the inside of the handhole to be easily and highly insulated. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a top view of a hand hole 1 according to a first embodiment. [Figure 2] 2 is a cross-sectional view of the hand hole 1 of the first embodiment taken along line AA. FIG. [Figure 3] FIG. 1 is a BB cross-sectional view of the hand hole 1 of the first embodiment. [Figure 4] 3 is a perspective schematic view illustrating the arrangement of a holding portion 32 of an inner lid 30 according to the first embodiment. FIG. [Figure 5] FIG. 1 is an explanatory diagram of a hand hole 107 in Patent Document 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] The handhole 1 of the present disclosure is used by embedding it underground in a guard's passageway beside a tunnel road. A handhole is an underground box used as a relay for inserting and removing cables during underground conduit installation work. The tunnel is preferably a road tunnel, and more preferably an expressway tunnel.

[0014] In expressway tunnels, fire hydrants are placed on the side walls of the tunnel at predetermined intervals along the road. The predetermined intervals are, for example, 50 meters. To supply water for fire fighting to these hydrants from outside the tunnel, water pipes are buried underground along the watchman's walkway beside the road. Handholes 1 are installed below the watchman's walkway corresponding to the fire hydrants.

[0015] First Embodiment FIG. 1 shows a top view of the handhole 1 of this embodiment, FIG. 2 shows a cross-sectional view taken vertically along plane AA in FIG. 1, FIG. 3 shows a cross-sectional view taken vertically along plane BB in FIG. 1, and FIG. 4 shows an oblique view of the interior of the handhole 1 including the holding portion 32.

[0016] The handhole 1 of this embodiment includes a frame 10, a cover portion 20, a water supply pipe 40, and an inner cover 30.

[0017] The frame 10 is made of concrete and forms the bottom 12 and sides 11 of the handhole 1.

[0018] The lid 20 includes an iron plate 21 and a handle 22. The iron plate 21 is a steel plate. More preferably, it is a checkered steel plate. In this embodiment, as can be seen from FIG. 1, the lid 20 includes three iron plates 21. Each iron plate 21 has four holes, to which two handles 22 are attached. The handles 22 are required to have the same heat resistance as the iron plate 21. The handles 22 are made of iron. The iron plate 21 can be lifted up by grasping the center of the handle 22. The handles 22 move up and down relative to the iron plate 21. When the handles 22 are not being grasped, they are housed in the iron plate 21 and hang down below the iron plate 21, as shown in FIG. 2. The handles 22 hang down about 70 mm from the underside of the iron plate 21 into the space S51 below.

[0019] The frame 10 and the lid 20 together form a box. The box is embedded in the ground so that the lid 20 is roughly at ground level. The frame 10 and the lid 20 together form an internal space S50, which is isolated from the outside air.

[0020] A water pipe 40 is arranged in the space S50 inside the handhole 1. As shown in FIG. 2, the water pipe 40 further penetrates the side portion 11 of the frame body 10 and extends along the road. Inside the handhole 1, the water pipe 40 branches off at a branching portion 41 and is laid out so as to supply water to a fire hydrant on the side of the tunnel (not shown). The water pipe 40 is a polyethylene pipe. To improve the heat resistance of the water pipe 40, a heat insulating layer may be formed around the polyethylene pipe.

[0021] The inner lid 30 is placed above the water pipe 40 and below the lid portion 20 in the space S50 inside the hand hole 1. The inner lid 30 divides the space S50 inside the hand hole 1 into a space S51 above the inner lid 30 and a space S52 below. The inner lid 30 includes a heat insulating material layer 31, a holding portion 32, and an attachment 33.

[0022] The heat insulating layer 31 includes a heat insulating material. The heat insulating material is, for example, rock wool, ceramic fiber, glass wool, cross-linked polyethylene foam, urethane foam, calcium silicate, or the like. Rock wool is more preferable. Above The surface is covered with ALGC (aluminum glass cloth). Above The surface may be made of a material other than ALGC. Having an ALGC surface on the insulating material improves the insulating performance.

[0023] The thickness of the heat insulating material layer 31 is 25 mm or more.

[0024] The holding portion 32 is, for example, a wire mesh (or other metal product). The holding portion 32 holds the heat insulating layer 31. The heat insulating layer 31 is placed on the holding portion 32. The heat insulating layer 31 divides the space S50 into an upper space S51 and a lower space S52.

[0025] The mounting fixture 33 is attached to the inner surface of the side portion 11 of the frame 10. The mounting fixture 33 is an L-shaped metal fitting (non-flammable metal fitting). The mounting fixture 33 fixes the holding portion 32 in a predetermined position.

[0026] The distance D between the iron plate 21 of the lid portion 20 and the inner lid 30 (or the insulating material layer 31) is, in other words, the height of the space S51. In this embodiment, the distance D is 100 mm. It is preferable that the distance D is long enough so that the lower part of the handle 22 does not come into contact with the insulating material layer 31. In this embodiment, the distance D is preferably 80 mm or more. This is because if the lower part of the handle 22 comes into contact with the insulating material layer 31, heat is transferred from the iron handle 22, making it easier for the temperature of the insulating material layer 31 to rise. On the other hand, if D is made too large, the space S52 in which the water supply pipe 40 is arranged becomes narrow, so it is preferable that it be 200 mm or less.

[0027] In the handhole 1 of this embodiment, not only the insulation layer 31 but also the air in the space S51 between the insulation layer 31 and the lid portion 20 serves as an insulating layer, and the water supply pipe 40 in the space S52 below the insulation layer 31 can be insulated from the heat above the lid portion 20 with excellent insulating performance.

[0028] (Example) Next, the results of an experiment in which the handhole 1 of this embodiment was actually fabricated as a prototype and the extent to which the internal space S50 rose when the cover portion 20 was heated from the outside will be described.

[0029] The following conditions are common to the following examples and comparative examples.

[0030] The size of the space S50 inside the handhole 1 is 750 mm in height, 1200 mm in the water supply direction of the water supply pipe 40, and 535 mm in width. Outside this, the concrete thickness of the side part 11 is 150 mm, and the concrete thickness of the bottom part 12 is 125 mm. A checkered steel plate with a thickness of 4.5 mm was used as the iron plate 21. Rock wool was used as the insulating material for the insulating material layer 31.

[0031] In Example 1, the distance D between the iron plate 21 and the heat insulating layer 31 was set to 100 mm. The heat insulating layer 31 had a thickness of 25 mm and a density of 120 kg / m 3 It is rock wool.

[0032] In Example 2, the distance D between the iron plate 21 and the heat insulating layer 31 was set to 162.5 mm. The heat insulating layer 31 had a thickness of 25 mm and a density of 70 kg / m 3 It is rock wool.

[0033] In Comparative Example 1, the distance D between the iron plate 21 and the heat insulating layer 31 was set to 0 mm. In other words, the heat insulating layer 31 was disposed in contact with the lower surface of the iron plate 21. The heat insulating layer 31 had a thickness of 25 mm and a density of 70 kg / m 3 The handle 22 extends downward from the iron plate 21 by 70 mm and is disposed so as to penetrate the heat insulating material layer 31.

[0034] For the samples of Example 1, Example 2, and Comparative Example 1, the outer surface of the iron plate 21 was heated to 1000°C or higher in multiple locations using a gas burner and held for one hour, and it was measured whether the surface of the water supply pipe 40 could be maintained at 80°C or lower.

[0035] In this experiment, the temperature of the rear surface of the iron plate 21 was 900°C or higher in all cases.

[0036] In the sample of Example 1, the outer surface of the iron plate 21 was continuously heated to 1000°C or higher, and the surface temperature of the water pipe 40 was 55.9°C after 60 minutes.

[0037] In the sample of Example 2, the outer surface of the iron plate 21 was continuously heated to 1000°C or higher, and the surface temperature of the water pipe 40 was 78.8°C after 60 minutes.

[0038] In the sample of Comparative Example 1, the outer surface of the iron plate 21 was continuously heated to 1000°C, and the temperature of the surface of the water supply pipe 40 exceeded 80°C in 24 minutes and 27 seconds. As the temperature continued to rise over time, the test was completed in 30 minutes.

[0039] As described above, the handhole 1 of this embodiment has a space S51 arranged between the iron plate 21 and the insulating material layer 31, and the air layer in this space S51 functions as an insulating layer, so it exhibits excellent insulating performance for the space S52 in which the water supply pipe 40 is arranged.

[0040] Furthermore, the handle 22 does not penetrate the insulating material layer 31 and does not even come into contact with the insulating material layer 31. The handle 22 is generally made of metal and is likely to act as a heat transfer path. The handhole 1 of this embodiment has the insulating material layer 31 located below the handle 22, and can sufficiently insulate the space S52 in which the water supply pipe 40 is located.

[0041] The handhole 1 of this embodiment can further improve the heat insulating performance by increasing the thickness of the heat insulating material layer 31. The heat insulating performance can be easily controlled. [Explanation of symbols]

[0042] 1 hand hole 10 Frame 11 Side 12 Bottom 20 Lid 21 Iron Plate 22 Handle 30 Inner lid 31 Insulation layer 32 Holding part 33 Mounting fixture 40 Water pipe 41 Branch S50 interior space S51 Space above the inner lid S52 Space below the inner lid

Claims

1. A box having a bottom, sides, and a lid, and a hand hole for receiving a water pipe inside the box, A concrete frame that constitutes the bottom and the side; the lid portion that closes the top of the frame body; The water supply pipe is disposed inside a box body formed by the frame body and the lid portion; an inner lid including a heat insulating layer disposed below the lid portion and spaced apart from the lid portion, the inner lid dividing the space inside the box into an upper space and a lower space including the water supply pipe; Equipped with The inner lid further includes a holding portion that holds the insulating layer below the insulating layer, A handhole, wherein the area of ​​the holding portion is approximately the same as the horizontal cross-sectional area of ​​the interior of the frame body, and the holding portion is a wire mesh.

2. The lid portion includes a metal plate and a metal handle attached to the metal plate, The inner lid is disposed below the lowest portion of the handle. The hand hole according to claim 1 .

3. The distance between the metal plate and the inner lid is 80 mm or more. The hand hole according to claim 2.

4. The insulation layer comprises rock wool. The hand hole according to any one of claims 1 to 3.

5. The hand holes are placed at predetermined intervals in the ground beneath the tunnel. The hand hole according to any one of claims 1 to 4.

Images