JP2012023886A - Handhole and handhole installation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a handhole and a handhole installation structure which can facilitate discharge from inside and can be restored with ease in a short time even when sand around it is firmly solidified.SOLUTION: A handhole is buried underground and comprises a bottom part, a sidewall part, cable insertion parts, an opening part, and a drain pipe. The bottom is positioned at the lowermost part. The sidewall part extends upward from the bottom part and is cylindrical in shape to form a housing chamber with the bottom part. The multiple cable insertion parts penetrate the sidewall part so that a cable can be inserted. The opening part penetrates the sidewall part, and the lower end of the opening part is positioned lower than the lower ends of the cable insertion parts. The drain pipe is inserted into the opening part to extend externally almost in parallel to the bottom part and guides the water flowing into the housing chamber to the outside of the housing chamber.

Description

  Embodiments described herein relate generally to a handhole and a handhole installation structure.

  Conventionally, in order to maintain cables such as electricity and telephones buried underground, hand holes are provided at predetermined intervals of the cables. The hand hole is formed in a cylindrical shape having a bottom portion, for example, with concrete or the like, and is buried in the ground. In such a handhole, water infiltrates into the inner storage chamber due to the surrounding precipitation. Therefore, the conventional hand hole forms a hole for draining by forming a thin wall portion thinner than the surrounding at the bottom and forming a hole penetrating the thin wall portion.

  However, when the handhole is buried in the ground, the support layer that supports the bottom of the handhole, that is, the bottom layer of the handhole, and the earth and sand layer below the support layer are firmly tamped in order to reliably support the handhole. Therefore, even if a drain hole is formed at the bottom, the water in the accommodation chamber formed by the hand hole is unlikely to penetrate into the tamped support layer and earth and sand layer. As a result, if there is a large amount of precipitation for a short time, such as torrential rain, the drainage of the handhole will be insufficient, causing cable corrosion and damage. In addition, when there is no power supply in the vicinity of the hand hole, drainage from the hand hole using an electric submersible pump becomes difficult, and there is a problem that a long time is required for restoration.

Japanese Utility Model Publication No. 6-24337

  In view of this, a hand hole and a hand hole installation structure that facilitates drainage from the inside and facilitates recovery in a short time even when the surrounding earth and sand are hardened firmly are provided.

  According to the hand hole of this embodiment, it is buried in the ground. The hand hole includes a bottom portion, a side wall portion, a cable insertion portion, an opening portion, and a drain pipe. The bottom is located at the bottom. The side wall portion has a cylindrical shape that extends upward from the bottom portion and forms a storage chamber together with the bottom portion. The plurality of cable insertion portions penetrates the side wall portion, and the cable is inserted. The opening portion penetrates the side wall portion, and the lower end is positioned below the lower end of the cable insertion portion. The drain pipe is inserted into the opening and extends outward substantially parallel to the bottom, and guides the water flowing into the storage chamber to the outside of the storage chamber.

Schematic sectional view showing a handhole and a handhole installation structure according to the first embodiment Viewed from the direction of arrow II in FIG. The schematic diagram equivalent to FIG. 1 which shows the handhole and handhole installation structure by 2nd Embodiment. Schematic diagram corresponding to FIG. 1 showing a handhole and a handhole installation structure according to the third embodiment Schematic diagram corresponding to FIG. 1 showing a handhole and a handhole installation structure according to the fourth embodiment Schematic diagram corresponding to FIG. 1 showing a handhole and a handhole installation structure according to the fifth embodiment

  Hereinafter, specific embodiments of the handhole and its installation structure will be described with reference to the drawings. In each embodiment, substantially the same components are assigned the same reference numerals, and descriptions thereof are omitted.

(First embodiment)
A handhole and its installation structure according to the first embodiment are shown in FIG. As shown in FIG. 1, the hand hole 10 includes a bottom portion 11 and a side wall portion 12. As described above, the hand hole 10 has the rectangular bottom portion 11, the side wall portion 12 is formed in a square tube shape, and is buried below the ground 13, that is, buried in the ground. In the hand hole 10, a bottom portion 11 and a side wall portion 12 are integrally formed of, for example, concrete. Thereby, the handhole 10 forms the accommodation chamber 14 surrounded by the bottom part 11 and the side wall part 12 inside. The end of the hand hole 10 opposite to the bottom 11 is open, and a lid member 15 is attached to the open end. The lid member 15 has an upper end surface located substantially on the same surface as the ground 13. The lid member 15 is detachable from the hand hole 10. In the case of the hand hole 10 having such a configuration, the operator can handle various devices accommodated in the accommodation chamber 14 of the hand hole 10 by removing the lid member 15. The handhole 10 is not limited to a rectangular tube shape, and can be formed into an arbitrary shape such as a polygonal tube shape, a cylindrical shape, or an elliptical cylinder shape.

  The hand hole 10 has a cable insertion portion 21 that penetrates the side wall portion 12. The cable insertion portion 21 penetrates the side wall portion 12 in the thickness direction and connects the accommodation chamber 14 inside the hand hole 10 and the outside. The cable 22 is inserted into the cable insertion portion 21. The cable 22 constitutes, for example, a power line or a telephone line buried in the ground. The cable 22 extends from the cable insertion portion 21 provided at one end of the hand hole 10 to the cable insertion portion 21 provided at the other end of the hand hole 10 via the accommodation chamber 14. The cable 22 includes intermediate devices (not shown) such as a repeater provided at an intermediate portion of the cable 22 and a joint connecting end portions. By storing these intermediate devices in the storage chamber 14 of the handhole 10, the intermediate devices are easily maintained.

  The outer side of the cable 22 is protected by a cable protection tube 23. The cable 22 has an outer diameter smaller than the inner diameter of the cable protection tube 23. Therefore, a gap corresponding to the difference in diameter is formed between the cable 22 and the cable protection tube 23. The cable protection tube 23 is attached to the cable insertion portion 21 on the outer peripheral side of the cable 22. Thereby, the cable protection tube 23 prevents the direct contact between the cable 22 and the hand hole 10 and protects the cable 22. A sealant 24 is filled between the cable protection tube 23 and the hand hole 10 on the outer peripheral side. The sealant 24 seals between the cable protection tube 23 and the cable insertion portion 21, and prevents water from entering the storage chamber 14 through the gap between the cable protection tube 23 and the side wall portion 12. .

  In addition to the cable insertion portion 21, the hand hole 10 has an opening 31 that penetrates the side wall portion 12. In addition, in FIG. 1, the display of the side wall part 12 between the opening part 31 and the cable insertion part 21 is abbreviate | omitted. In the opening 31, the lower end, that is, the end on the bottom 11 side is located below the lower end of the cable insertion portion 21, that is, on the bottom 11 side. That is, as shown in FIG. 2, the lower end of the opening 31 is located below the lower end of the cable insertion portion 21. Similar to the cable insertion portion 21, the opening portion 31 penetrates the side wall portion 12 and connects the accommodation chamber 14 and the outside of the hand hole 10.

  The hand hole 10 includes a drain pipe 32 inserted into the opening 31. The drain pipe 32 is inserted into the opening 31 and extends to the outside of the hand hole 10 substantially parallel to the bottom 11. The drain pipe 32 forms a pipe end 33 at the end opposite to the storage chamber 14. For example, rainwater or the like that has entered the inside of the storage chamber 14 is discharged to the outside of the storage chamber 14 via the drain pipe 32 inserted into the opening 31. That is, the water that has entered the storage chamber 14 is guided to the drain pipe 32 and discharged to the outside of the hand hole 10.

  The above-described handhole 10 is buried in the ground as shown in FIG. In this case, a support layer portion 41 is provided on the bottom 11 side of the hand hole 10 in order to hold the hand hole 10 firmly in the ground. The support layer portion 41 is formed of a tamped earth and sand layer or concrete. The support layer portion 41 is formed horizontally in order to hold the handhole 10. The earth and sand layer 42 is located further below the support layer portion 41. The earth and sand layer 42 is located above a groundwater vein (not shown).

  On the other hand, a protective earth and sand layer 51 is provided outside the hand hole 10, that is, outside the side wall portion 12. The protective earth and sand layer 51 is an earth and sand layer that protects the cable 22 extending from the hand hole 10, and is provided to other hand holes 10 that are adjacent along the cable 22. The protective earth and sand layer 51 is formed of earth and sand having a relatively coarse mesh, and relatively high water permeability is ensured. A normal earth and sand layer 42 is located around the periphery including the lower part of the protective earth and sand layer 51. In FIG. 1, the boundary between the protective earth / sand layer 51 and the earth / sand layer 42 is clearly shown, but the boundary between the protective earth / sand layer 51 and the earth / sand layer 42 is actually discontinuous and unclear.

  The hand hole 10 may be provided with a drain hole 61 penetrating in the thickness direction in the bottom portion 11. The drain hole 61 connects the water collecting recess 62 provided at the end portion of the bottom portion 11 on the storage chamber 14 side and the outside of the bottom portion 11. A bottom drain pipe 63 is inserted into the drain hole 61. One end of the bottom drain pipe 63 is located in the water collecting recess 62 of the bottom 11, and the other end is located in the earth and sand layer 42 below the support layer 41. As a result, the water collected in the water collecting recess 62 is discharged to the earth and sand layer 42 via the bottom drain pipe 63.

Thus, the hand hole 10 and the protective earth and sand layer 51 described above constitute a hand hole installation structure.
In the case of the hand hole 10 as described above, water accumulates in the accommodation chamber 14 inside the hand hole 10 due to rain or the like. In a normal case, the water that has entered the storage chamber 14 is collected in the water collecting recess 62 and discharged to the earth and sand layer 42 through the bottom drain pipe 63. However, the earth and sand layer 42 below the support layer portion 41 forms a support layer portion 41 and is firmly tamped in order to support the handhole 10. Therefore, the water passing through the bottom drain pipe 63 hardly penetrates into the earth and sand layer 42 located below the support layer part 41. As a result, particularly when there is a large amount of precipitation in a short time such as torrential rain, drainage from the storage chamber 14 may be insufficient. If the drainage from the storage chamber 14 becomes insufficient, the cable 22 or an intermediate device (not shown) provided in the cable 22 may be flooded inside the hand hole 10.

  Therefore, in the case of the first embodiment, the handhole 10 includes a drain pipe 32 inserted into the opening 31. The lower end of the opening 31 into which the drain pipe 32 is inserted is located below the lower end of the cable insertion portion 21 into which the cable 22 is inserted. And as for the drainage pipe 32, the pipe end part 33 which is an edge part on the opposite side to the storage chamber 14 is opening to the protective earth-and-sand layer 51 with high water permeability. Therefore, the water in the storage chamber 14 is drained not only from the bottom drain pipe 63 but also from the drain pipe 32. Specifically, when water enters the storage chamber 14 inside the hand hole 10 and only drainage from the bottom drain pipe 63 is insufficient, the water level in the storage chamber 14 rises toward the lid member 15. When the water level in the storage chamber 14 reaches the opening 31, the water in the storage chamber 14 is drained from the pipe end 33 through the drain pipe 32 to the protective soil layer 51 having high water permeability. As a result, drainage from the storage chamber 14 to the outside is promoted.

  In addition, as described above, the lower end of the opening 31, that is, the lower end of the drain pipe 32 is located below the lower end of the cable insertion portion 21. Therefore, before the water level in the storage chamber 14 reaches the cable 22, drainage from the drain pipe 32 is started. As a result, flooding of the cable 22 and the intermediate device stored in the storage chamber 14 is avoided. Further, even if they are submerged by the rise in the water level in the storage chamber 14, the water in the storage chamber 14 is drained to the protective earth and sand layer 51 via the drain pipe 32. Thereby, the storage chamber 14 can be quickly removed from the flooded state, and the cable 22 and the intermediate device can be quickly restored.

  As described above, in the first embodiment, the water that has entered the storage chamber 14 is drained to the protective earth and sand layer 51 not only through the bottom drain pipe 63 but also through the drain pipe 32 inserted into the opening 31. . In the drainage pipe 32, the pipe end 33 on the side opposite to the storage chamber 14 faces the protective earth and sand layer 51 having a coarse mesh having high water permeability. Therefore, the water in the storage chamber 14 is quickly drained to the external protective soil layer 51 via the drain pipe 32. Therefore, even when the earth and sand layer 42 below the support layer portion 41 is firmly tamped, drainage from the storage chamber 14 can be promoted. Moreover, since the drainage from the storage chamber 14 is promoted, the cable 22 and the intermediate device can be easily restored in a short time.

  In the first embodiment, the lower end of the opening 31 into which the drain pipe 32 is inserted is located below the lower end of the cable insertion portion 21. Therefore, the water in the storage chamber 14 flows into the drain pipe 32 before the water level reaches the cable 22. Therefore, it is possible to avoid inundation of the cable 22 and the intermediate device in advance. Further, even if the cable 22 or the intermediate device is flooded due to unexpected precipitation, the water in the storage chamber 14 is quickly drained from the drain pipe 32 positioned below. Therefore, the cable 22 and the intermediate device stored in the storage chamber 14 can be restored in a short time.

(Second Embodiment)
FIG. 3 shows a handhole and a handhole installation structure according to the second embodiment.
In the case of 2nd Embodiment, as shown in FIG. 3, the drain pipe 32 has the some hole 71 in the lower end side in the middle. The hole 71 passes through the drain pipe 32 and connects the inside and the outside. Thereby, the water flowing through the drainage pipe 32 flows out not only from the pipe end portion 33 at the tip but also from the hole 71 in the middle. The drain pipe 32 is covered with a protective earth and sand layer 51 together with the cable 22. Therefore, the water in the drain pipe 32 is absorbed into the protective earth and sand layer 51 from the pipe end 33 and the hole 71.
As mentioned above, in 2nd Embodiment, the water discharged | emitted from the storage chamber 14 osmose | permeates the protective earth-and-sand layer 51 not only from the pipe end part 33 of the drain pipe 32 but from the hole 71. FIG. Therefore, the water in the storage chamber 14 can be drained more quickly and reliably.

(Third embodiment)
FIG. 4 shows a handhole and a handhole installation structure according to the third embodiment.
The drain pipe 32 of 3rd Embodiment has the hole 71 similarly to 2nd Embodiment. In the case of the third embodiment, a water absorption layer 72 is provided in a portion facing the hole 71 of the drain pipe 32, that is, below the hole 71 of the drain pipe 32. The water absorption layer 72 has water permeability that is the same as or close to that of the protective soil layer 51. The water absorption layer 72 is set in an arbitrary range below the protective earth and sand layer 51 and continuously with the protective earth and sand layer 51. As a result, the water discharged from the pipe end 33 and the hole 71 of the drain pipe 32 penetrates not only the protective earth and sand layer 51 but also the water absorption layer 72. Thus, by providing the water absorption layer 72 continuous to the protective earth and sand layer 51, the water absorption in the periphery of the drain pipe 32 is improved. As a result, even if the amount of water discharged from the handhole 10 is increased, a decrease in drainage is suppressed.

  As described above, in the third embodiment, the water discharged from the storage chamber 14 penetrates not only the protective earth and sand layer 51 but also the water absorbing layer 72 through the drain pipe 32. As a result, the amount of water that can be absorbed around the drain pipe 32 increases. Therefore, the water in the storage chamber 14 can be drained more quickly and reliably.

(Fourth embodiment)
FIG. 5 shows a handhole and a handhole installation structure according to the fourth embodiment.
In the drain pipe 32 of the fourth embodiment, an end 81 on the side of the storage chamber 14 protrudes into the storage chamber 14, and a floating member 82 is provided at the end 81. As a result, the end 81 of the drainage pipe 32 on the storage chamber 14 side moves up and down in the storage chamber 14 following the floating member 82. That is, the water level of the water flowing into the storage chamber 14 changes up and down. By providing the floating member 82 at the end 81 of the drain pipe 32, the end 81 of the drain pipe 32 moves up and down according to the change in the water level in the storage chamber 14.

  In such a fourth embodiment, when the water level in the storage chamber 14 rises to a level H higher than that of the cable 22 due to sudden water increase, the end 81 of the drain pipe 32 is also raised by the floating member 82. Move to the vicinity. Therefore, the water in the storage chamber 14 is drained from the higher position close to the water level H to the protective soil layer 51 via the drain pipe 32. As a result, drainage from the storage chamber 14 is promoted. On the other hand, when the water level in the storage chamber 14 drops to the water collecting recess 62, the pipe end 33 of the drain pipe 32 that follows the floating member 82 also moves to the vicinity of the bottom 11. At this time, if the water is continuously drained through the drain pipe 32, the water collected in the water collecting recess 62 lower than the drain pipe 32 is also drained from the drain pipe 32 to the protective earth and sand layer 51 by the siphon principle. Is done. As a result, the water in the storage chamber 14 is drained regardless of the water level in the storage chamber 14.

  In the fourth embodiment, by providing a floating member 82 at the end 81 of the drain pipe 32 on the accommodation chamber 14 side, the end 81 moves up and down following the floating member 82 that rises and falls according to the water level in the accommodation chamber 14. To do. Therefore, when the water level in the storage chamber 14 is high, a flow of water from a higher position to the protective soil layer 51 is formed. Therefore, the water inside the storage chamber 14 can be quickly drained. Even when the water level in the storage chamber 14 changes below the opening 31, the water in the storage chamber 14 is discharged to the outside of the storage chamber 14 by the siphon principle. Therefore, the water in the storage chamber 14 can be drained to the outside regardless of the water level in the storage chamber 14.

(Fifth embodiment)
FIG. 6 shows a handhole and a handhole installation structure according to the fifth embodiment.
In the first to fourth embodiments described above, the example in which the drain pipe 32 is inserted into the opening 31 different from the cable insertion portion 21 into which the cable 22 is inserted has been described.
On the other hand, in the case of the fifth embodiment, the handhole 10 has only the opening 91 penetrating the side wall 12 in the side wall 12. A drain pipe 92 is inserted into the opening 91. The cable 22 and the cable protection tube 23 are inserted inside the drain pipe 92. That is, the cable 22 and the cable protection pipe 23 are inserted inside the drain pipe 92 inserted into the opening 91. At this time, the cable protection tube 23 that protects the outer peripheral side of the cable 22 is supported by the sleeve 93 or the like inside the drain tube 92 so as not to contact the drain tube 92. The sleeve 93 extends radially from the cable protection tube 23. Accordingly, a gap 94 through which water flows is formed between the lower end of the cable protection tube 23 and the lower end of the drainage pipe 92.

In the case of the fifth embodiment as well, as in the first to fourth embodiments, when the water level flowing into the storage chamber 14 rises, the water in the storage chamber 14 is drained from the cable protection pipe 23 and the drain pipe. It drains to the protective earth and sand layer 51 through the gap 94 between the two. In this case, the lower end of the opening 91 into which the drain pipe 92 is inserted is located below the lower end of the cable protection pipe 23. Therefore, before the water level reaches the cable protection pipe 23, the water in the storage chamber 14 is drained to the protective earth and sand layer 51 through the drain pipe 92.
As described above, in the fifth embodiment, the cable protection pipe 23 and the drain pipe 92 are inserted into the opening 91. Therefore, the number of openings 91 to be processed in the side wall portion 12 of the hand hole 10 is reduced. Therefore, the processing of the hand hole 10 can be facilitated.

  As mentioned above, although several embodiment of this invention was described, these embodiment was shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  In the drawings, 10 is a hand hole, 11 is a bottom portion, 12 is a side wall portion, 14 is a storage chamber, 21 is a cable insertion portion, 22 is a cable, 31 and 91 are openings, 32 and 92 are drain pipes, and 51 is protective earth and sand. The layer, 71 is a hole, 72 is a water absorption layer, 82 is a floating member, and 94 is a gap.

Claims (5)

A handhole buried in the ground,
The bottom located at the bottom,
A cylindrical side wall extending upward from the bottom and forming a storage chamber with the bottom; and
A plurality of cable insertion parts through which the cable is inserted,
An opening that penetrates the side wall and has a lower end positioned below the lower end of the cable insertion portion,
A drain pipe that is inserted into the opening and extends outward substantially parallel to the bottom, and guides the water flowing into the storage chamber to the outside of the storage chamber;
Hand hole equipped with.   The hand hole according to claim 1, wherein the drain pipe has a plurality of holes connecting the inner side and the outer side on a lower end side.   3. The handhole according to claim 1, wherein the drain pipe has a floating member at an end portion on the accommodation chamber side, and the end portion is movable up and down inside the accommodation chamber together with the floating member. A handhole buried in the ground,
The bottom located at the bottom,
A cylindrical side wall extending upward from the bottom and forming a storage chamber with the bottom; and
An opening through the side wall,
A cable is supported while forming a gap with the lower end, inserted inside the opening, and extended outward substantially parallel to the bottom to guide the water flowing into the storage chamber to the outside of the storage chamber. Drainage pipes,
Hand hole equipped with. The hand hole according to any one of claims 1 to 4,
A protective earth and sand layer covering the outside of the drain pipe on the virtual extension line extending the central axis of the opening, protecting the outside of the drain pipe, and having water permeability;
Provided in the portion where water is discharged from the drain pipe in the protective earth and sand layer, has a water permeability that is the same as or close to that of the protective earth and sand layer, and a water absorption layer continuous to the protective earth and sand layer,
Handhole installation structure with.

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