JP5139377B2 - Manhole floating prevention structure - Google Patents

Description

  The present invention relates to a manhole levitation preventing structure for preventing the buoyancy of an embedded manhole body or the like due to a ground liquefaction phenomenon during an earthquake or the like.

As shown in FIG. 6, the conventional manhole 51 is used for inspection of buried pipes and the like. Mainly, a manhole body 53 buried in a standing pile shape in the ground 52, and the manhole body 53 An iron frame 54 attached to the upper part and an iron cover manhole cover 55 installed on the upper part of the iron frame 54 so as to be openable and closable are provided. Of these, the manhole body 53 is configured by providing a foundation such as crushed stone at the bottom of a manhole hole in the ground 52 and sequentially laminating a bottom plate, a pipe mounting wall, a straight wall, a slanted wall, etc. on the foundation. ing. The iron frame 54 is directly attached by being fastened and fixed using a plurality of anchor bolts 56 or the like with the peripheral flange portion placed on the upper portion of the manhole body 53. It is integrated with.
Therefore, in the conventional manhole 51, when the ground 52 is liquefied due to an earthquake or the like and the embedded manhole body 53 is lifted by an action such as buoyancy, the sewer pipe attached to the lower portion of the manhole body 53 is detached. In addition, there is a problem that the iron frame 54 and the manhole cover 55 directly attached to the upper portion of the manhole body 53 protrude on the road surface and obstruct the passage of vehicles and people.

Thus, as one of means for preventing the manhole from rising during an earthquake or the like, a technique disclosed in, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2006-183450) has been provided.
In the technique of Patent Document 1, a plurality of through holes are drilled in a peripheral wall of an embedded manhole, and a strut material is placed in the outer diameter direction from the inside of the manhole through these through holes to fix the manhole to the ground side. Even if a liquefaction phenomenon occurs in the ground during an earthquake, the manhole is prevented from rising.

JP 2006-183450 A

  However, in the above-described conventional technique, an operator enters the inside of an existing manhole embedded in a standing pile shape on the site, and after drilling a plurality of through holes in the peripheral wall of the manhole, the inside of the manhole Since it is necessary to place the strut material in the outer diameter direction and fix the manhole to the ground side, the entire device is large and requires large-scale construction, and the construction work is complicated and the construction cost is high. In addition, a lot of construction time was required, and there was a problem that the passage of vehicles and people was stopped for a long time.

  The present invention has been made in view of such a situation, and the object thereof is to suppress manhole levitation caused by the liquefaction phenomenon of the ground occurring during an earthquake and the like, and an extremely simple structure. Therefore, it is an object of the present invention to provide a manhole floating prevention structure that does not require a large-scale construction, can be constructed at a low cost in a short time, and can be easily applied to an existing manhole.

In order to solve the above-described problems of the prior art, the present invention provides a ring-shaped weight body around the upper portion of an embedded manhole body, and joins between the manhole body and a receiving frame on which a manhole cover is installed. In the structure for preventing the rise of the manhole by integrating the weight body and the manhole body by arranging the member and joining the receiving frame and the manhole body via the joining member ,
The joint member is provided between the upper and lower sides of the receiving frame and the manhole body, and is provided on a ring-shaped body portion located on the inner peripheral side of the weight body, and on an outer periphery of the body portion. A plurality of arm portions extending in the radial direction until the arm portions are joined to the weighted body, the joining member is attached to the weighted body, and the body portion is interposed, By joining the receiving frame and the manhole body, the weight body is attached to the manhole body via the joining member .

Further, the present invention provides a ring-shaped weight body around the upper part of the buried manhole body, disposes a joining member between the manhole body and a receiving frame on which a manhole cover is installed, By joining the receiving frame and the manhole body, in the manhole floating prevention structure in which the weight body and the manhole body are integrated,
The joining member is between the upper and lower sides of the receiving frame and the manhole body, and is a ring-shaped small-diameter main body portion located on the inner peripheral side of the weight body, and below the small-diameter main body portion, and the weight body A ring-shaped large-diameter main body portion located on the outer peripheral side of the main body and a plurality of arm portions connecting the small-diameter main body portion and the large-diameter main body portion, and the weight body is placed on the large-diameter main body portion . By joining in the state, the weight body is attached to the joining member, and the weight body is joined to the joining member by joining the receiving frame and the manhole body with the small diameter main body interposed therebetween. It is attached to the manhole body via

Further, in the present invention, concrete is placed on and around the receiving frame, the joining member, and the weight body, and the weight of the weight body and the placement of the placed concrete are placed at the time of liquefaction. It is comprised so that a load may become weight .

  As described above, in the manhole floating prevention structure according to the present invention, a ring-shaped weight body is installed around the upper portion of an embedded manhole body, and a joining member is provided between the manhole body and a receiving frame on which a manhole cover is installed. Since the weight body and the manhole body are integrated by joining the receiving frame and the manhole body via the joining member, the weight of the weight body is always added to the manhole body. In addition, the effect of buoyancy generated by liquefaction of the ground during an earthquake or the like can be suppressed by the load of the weighted body, and the manhole can be prevented from rising.

  Moreover, in the manhole floating prevention structure according to the present invention, the weighted body of the secondary product is arranged on the outer periphery of the manhole body, and the receiving frame and the manhole body are joined via the joining member arranged between the manhole body and the receiving frame. As a result, an integrated structure of the weighted body and the manhole body can be obtained, so the structure is extremely simple, there is no need for large-scale construction, and the construction can be performed quickly at a low cost in a short time. At the same time, it can be easily applied to existing manholes and has excellent versatility.

Further, in the anti-floating structure of the present invention, the joining member is between the upper and lower sides of the receiving frame and the manhole body, and is located on the inner peripheral side of the weight body. A plurality of arm portions provided on the outer periphery and extending in a radial direction to the outer periphery of the weight body, and by joining the arm portions to the weight body, the joining member is attached to the weight body, The weight body is attached to the manhole body via the joining member by joining the receiving frame and the manhole body with the body portion interposed, or the joining member is attached to the receiving frame. A ring-shaped small-diameter main body portion located between the upper and lower sides of the manhole main body and located on the inner peripheral side of the weight body, and a ring-shaped portion located below the small-diameter main body portion and on the outer peripheral side of the weight body of The weight body includes a diameter main body portion, and a plurality of arm portions that connect the small diameter main body portion and the large diameter main body portion, and the weight body is joined in a state of being placed on the large diameter main body portion. Is attached to the joining member, and the weight body is attached to the manhole body via the joining member by joining the receiving frame and the manhole body with the small-diameter body portion interposed therebetween. Therefore, the weight body that directly applies the load to the manhole body can be reliably integrated with the manhole body by a simple construction work.
In addition, in the anti-floating structure of the present invention, the weighted body can be installed in the manhole body without modifying the manhole structure, so that the appearance on the road surface can be maintained unchanged from the normal manhole. The existing iron lid can be reused and the ecology can be improved.

  Further, in the anti-floating structure of the present invention, concrete is placed on and around the receiving frame, the joining member, and the weighted body, and the weight of the weighted body and the placed weight are placed during liquefaction. It is configured so that the load on the concrete surface becomes heavy, so even if an action to float on the manhole body occurs due to an earthquake, etc., the manhole body etc. Can be suppressed.

It is a manhole to which the anti-levitation structure according to the first embodiment of the present invention is applied, wherein (a) is a plan view thereof and (b) is a longitudinal sectional view thereof. FIG. 1 shows a manhole body constituting the manhole of FIG. 1 and a weight body integrated with the manhole body by a joining member in a state before the receiving frame and the manhole cover are attached, (a) is a plan view thereof, (b). Is a longitudinal sectional view thereof. It is a manhole to which the anti-levitation structure according to the second embodiment of the present invention is applied, wherein (a) is a plan view thereof and (b) is a longitudinal sectional view thereof. 3 is a manhole body constituting the manhole of FIG. 3 and a weight body integrated with the manhole body by a joining member in a state before attaching the receiving frame and the manhole cover, (a) is a plan view thereof, (b). Is a longitudinal sectional view thereof. It is a perspective view which shows the joining member in FIG.3 and FIG.4. It is a longitudinal cross-sectional view which shows the conventional manhole.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a manhole floating prevention structure according to the present invention will be described in detail based on the illustrated embodiment.

[First Embodiment]
FIG. 1 is a manhole to which the anti-floating structure according to the first embodiment of the present invention is applied, wherein (a) is a plan view of the manhole in a state where non-shrinkable concrete is removed, and (b) is a manhole. It is a longitudinal cross-sectional view. FIG. 2 shows a manhole body constituting the manhole of FIG. 1 and a weight body integrated with the manhole body by a joining member in a state before the receiving frame and the manhole cover are attached, and (a) is a plan view thereof. , (B) is a longitudinal sectional view thereof.

The manhole 1 of the present embodiment has a structure that prevents the buried portion from floating due to the liquefaction phenomenon of the ground during an earthquake or the like. As shown in FIGS. A concrete manhole body 3 embedded in a standing pile shape is provided inside. In order to use the manhole body 3 for inspection of buried pipes, for example, one or a plurality of trunk blocks (not shown), which are cylindrical precast concrete blocks, are stacked, It is configured by further stacking a cylindrical upper block 4 that is inclined upward and tapered in an upward direction.
On the other hand, a bottom plate (not shown) is provided at the bottom of the manhole body 3, and an invert block (not shown) in which an invert is formed is provided on the bottom plate. An external sewage pipe is connected to allow the drainage to flow inside the manhole body 3.

  Further, on the upper outer periphery of the manhole body 3, the ground surface (paved surface) 2a around the manhole 1 is cut into a circle (or a rectangle) and excavated to a predetermined depth, and the bottom surface of the excavated area is flattened flat. A recessed portion 5 is provided. On the bottom surface of the recess 5, a ring-shaped weight body 6, which is one of the characteristic portions of the embodiment of the present invention, is integrated with the manhole body 3 and can apply a load to the manhole body 3 at all times. It is arranged around the upper part of the main body 3.

The weighted body 6 is a transportable concrete secondary product manufactured in advance in a factory or the like, and is formed separately from the manhole body 3, and has a predetermined thickness according to the size of the embedded manhole body 3, The inner and outer diameters (widths) and weights are provided, and one or a plurality (two in this embodiment) are installed corresponding to the depth of the recess 5. Therefore, a through hole 6 a having a diameter larger than the upper outer diameter of the manhole body 3 is formed at the center of the weight body 6, and the weight body 6 is installed around the upper outer periphery of the manhole body 3 through the through hole 6 a. It is possible.
In addition, when the weight body 6 is liquefied, for example, the weight 6 has a total weight of about 1 t with an overlay load of non-shrinkable concrete, which will be described later, so as to function as a weight of a standard manhole 1 having a height of 4 m. The weight and the number of installations are set. The upper surface of the weighted body 6 that is stacked is installed at a depth position that is substantially flush with the upper surface of the manhole body 3.

  On the other hand, on the upper surface of the manhole body 3, as shown in FIG. 1, there is placed a receiving frame 8 for installing the manhole cover 7 of an iron lid in a state where it can be opened and closed. In addition, a joining member 9 that is one of the characteristic portions of the embodiment of the present invention is disposed between the manhole body 3 and the receiving frame 8, and the receiving frame 8 and the manhole body 3 are connected via the joining member 9. The weight body 6 and the manhole body 3 are integrated with each other by fastening with a plurality of fastening bolts 10, and the weight of the weight body 6 is always applied to the manhole body 3. In addition, the receiving frame 8 is embedded so that the upper surface of the manhole cover 7 installed in the central receiving surface portion is substantially flush with the ground surface 2a.

  As shown in FIGS. 1 and 2, the joining member 9 of the present embodiment is between the upper and lower surfaces of the lower surface of the receiving frame 8 and the upper surface of the manhole body 3 and on the inner peripheral side of the weight body 6 having the through holes 6 a. A ring-shaped main body portion 9a is provided, and a plurality (three in this embodiment) of arm portions 9b are provided on the outer periphery of the main body portion 9a and extend in the radial direction to the outer periphery of the weight body 6. .

The main body portion 9a has inner and outer diameters that can be placed on the upper portion of the manhole body 3 and on which the receiving frame 8 can be placed, and bolt holes into which the fastening bolts 10 are inserted are formed at regular intervals in the circumferential direction. Yes. The arm portions 9b are formed at a constant interval in the circumferential direction of the main body portion 9a, and the end portions of the arm portions 9b are placed on the weight body 6 and joined by being fastened with the anchor bolts 11 respectively. A member 9 is attached to the weight body 6. Further, the weight body 6 is integrally attached to the manhole body 3 via the joining member 9 by joining the receiving frame 8 and the manhole body 3 with the plurality of fastening bolts 10 with the body portion 9a interposed. ing.
When two weight bodies 6 are stacked and installed as in this embodiment, anchor bolts 11 that are longer than the thickness of the two weight bodies 6 are used. By tightening and fixing, the two weight bodies 6 and the joining member 9 are tightly coupled.

  Further, as shown in FIG. 1B, non-shrinkable concrete 12 having excellent fluidity and the like is substantially flush with the ground surface 2a at the upper part and the periphery of the receiving frame 8, the joining member 9, and the weighted body 6. It is provided to such a height position. This non-shrinkable concrete 12 is driven at a construction site after the receiving frame 8, the joining member 9, the weighted body 6, and the like are installed. The weight of the weight 6 and the loaded load of the non-shrinkable concrete 12 is configured as a weight of the manhole 1 at the time of liquefaction, and when the manhole 1 rises due to an earthquake or the like, It has a function to suppress the manhole 1 from rising.

The structure for preventing the manhole 1 from floating according to the first embodiment of the present invention first cuts the ground surface 2a above the manhole of the manhole body 3 of the existing manhole 1 to a predetermined depth by an existing cutting machine. The removed part and the existing steel frame are removed. After the removal is completed, the bottom surface of the formed concave portion 5 is leveled, two weighted bodies 6 of concrete secondary products are put into the concave portion 5, and the weighted body 6 is placed around the upper outer periphery of the manhole body 3 through the through hole 6 a. Install. Then, the joining member 9 is placed on a predetermined position on the upper surface of the weighting body 6 positioned above, and the joining member 9 is attached to the weighting body 6 by fastening the tip portions of the arm portions 9b with the anchor bolts 11 respectively. (See FIG. 2).
Next, the receiving frame 8 is placed on the upper surface of the main body portion 9a of the joining member 9, and the receiving frame 8 is fastened and fixed with fastening bolts 10 to attach the receiving frame 8 and the manhole body. Tie 3 together. Thereafter, non-shrinkable concrete 12 is driven into the upper part and the periphery of the receiving frame 8, the joining member 9 and the weighted body 6 and cured for a predetermined time, and if the manhole cover 7 is installed on the receiving surface portion of the receiving frame 8, the manhole 1 is lifted. A prevention structure is obtained (see FIG. 1).

  As described above, in the structure for preventing the manhole 1 from rising according to the first embodiment of the present invention, the upper portion of the manhole body of the existing manhole body 3 is cut, and the upper portion and the existing iron frame are removed to form the recess 5. The ring-shaped load body 6, which is a separate and independent concrete secondary product, is installed around the upper portion of the manhole body 3, and the end portion of the arm portion 9 b is fastened and fixed with the anchor bolt 11, and the joining member 9 is attached to the load body 6. While mounting, the receiving frame 8 is fastened to the upper part of the manhole body 3 by interposing the body portion 9a of the joining member 9, and the weight body 6 and the manhole body 3 are integrated. The weight of the weight body 6 is applied to the manhole body 3, and the manhole body 3, the receiving frame 8, and the manhole cover 7 are prevented from floating on the ground surface 2a due to the liquefaction phenomenon of the ground 2. It can be. In addition, the anti-floating structure of the present embodiment is simple in structure and does not require large-scale field work, so it can be quickly installed at low cost and in a short time.

  Further, in the floating prevention structure of the present invention, the non-shrinkable concrete 12 is placed on and around the weight body 6 and the receiving frame 8, and the weight body 6 is placed with its own weight during the liquefaction phenomenon. Since the overlay load of the non-shrinkable concrete 12 becomes a weight, the floating of the manhole 1 due to an earthquake or the like can be further suppressed.

[Second Embodiment]
FIG. 3 is a manhole to which the anti-levitation structure according to the second embodiment of the present invention is applied, wherein (a) is a plan view of the manhole in a state where non-shrinkable concrete is removed, and (b) is a manhole. It is a longitudinal cross-sectional view. FIG. 4 shows a manhole body constituting the manhole of FIG. 3 and a weight body integrated with the manhole body by a joining member in a state before the receiving frame and the manhole cover are attached, and (a) is a plan view thereof. , (B) is a longitudinal sectional view thereof. FIG. 5 is a perspective view of the joining member in FIGS. 3 and 4.

  In the floating prevention structure of the present embodiment, a joining member 19 having a different structure is used instead of the joining member 9 of the first embodiment. The joining member 19 includes a ring-shaped small-diameter main body portion 19a located between the upper and lower sides of the receiving frame 8 and the manhole main body 3 and on the inner peripheral side of the weight body 6 having the through holes 6a, and the small-diameter main body portion 19a. A ring-shaped large-diameter main body portion 19b positioned on the outer peripheral side of the weight body 6 and a plurality of arm portions 19c that connect the small-diameter main body portion 19a and the large-diameter main body portion 19b are provided.

The small-diameter main body 19a has inner and outer diameters that can be placed on the upper portion of the manhole body 3 and on which the receiving frame 8 can be placed, and bolt holes for inserting the fastening bolts 10 are formed at regular intervals in the circumferential direction. ing. The large-diameter main body 19b is formed concentrically with a constant interval outside the outer periphery of the small-diameter main body 19a. Bolt holes into which the anchor bolts 11 are inserted are drilled at a constant interval in the circumferential direction. Has been. The weight body 6 is placed on the upper surface of the large-diameter main body portion 19b. The weight body 6 is placed on the large-diameter main body portion 19b and fastened with the anchor bolts 11 to join the weight body 6. It is attached to the joining member 19. Further, the weight body 6 is integrally attached to the manhole body 3 via the joining member 19 by joining the receiving frame 8 and the manhole body 3 with the plurality of fastening bolts 10 with the small diameter body portion 19a interposed. It has been.
Other configurations, construction methods, and effects are substantially the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.
For example, the floating prevention structure of the present invention can be applied not only to the existing manhole 1 but also to a newly installed manhole. Further, when the height adjusting concrete is provided on the upper portion of the manhole body 3, the anti-floating structure of the present invention does not directly join the joining members 9 and 19 to the manhole body 3, It is also possible to join to the height-adjusting concrete.

DESCRIPTION OF SYMBOLS 1 Manhole 2 Ground 3 Manhole body 5 Recessed part 6 Weighted body 7 Manhole cover 8 Receiving frame 9 Joining member 9a Body part 9b Arm part 10 Fastening bolt 11 Anchor bolt 12 Non-shrinkable concrete 19 Joining member 19a Small diameter body part 19b Large diameter body part 19c Arm part

Claims (3)

A ring-shaped weight body is installed around the upper part of the buried manhole body, a joining member is disposed between the manhole body and a receiving frame on which a manhole cover is installed, and the receiving frame and the manhole are interposed via the joining member. In the structure for preventing the manhole from rising , the weight body and the manhole body are integrated by joining the main body .
The joint member is provided between the upper and lower sides of the receiving frame and the manhole body, and is provided on a ring-shaped body portion located on the inner peripheral side of the weight body, and on an outer periphery of the body portion. A plurality of arm portions extending in the radial direction until the arm portions are joined to the weighted body, the joining member is attached to the weighted body, and the body portion is interposed, A structure for preventing a manhole from floating , wherein the weight body is attached to the manhole body via the joining member by joining the receiving frame and the manhole body . A ring-shaped weight body is installed around the upper part of the buried manhole body, a joining member is disposed between the manhole body and a receiving frame on which a manhole cover is installed, and the receiving frame and the manhole are interposed via the joining member. In the structure for preventing the manhole from rising, the weight body and the manhole body are integrated by joining the main body.
The joining member is between the upper and lower sides of the receiving frame and the manhole body, and is a ring-shaped small-diameter main body portion located on the inner peripheral side of the weight body, and below the small-diameter main body portion, and the weight body A ring-shaped large-diameter main body portion located on the outer peripheral side of the main body and a plurality of arm portions connecting the small-diameter main body portion and the large-diameter main body portion, and the weight body is placed on the large-diameter main body portion . By joining in the state, the weight body is attached to the joining member, and the weight body is joined to the joining member by joining the receiving frame and the manhole body with the small diameter main body interposed therebetween. floating preventing structure between Nhoru, characterized in that attached to the manhole body through. Concrete is placed over and around the receiving frame, the joining member, and the weighted body, and the weight of the weighted body and the overlay load of the placed concrete become a weight when liquefied. The structure for preventing a manhole from floating according to claim 1 or 2 , wherein the structure is configured as follows.

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