JP2006152542A - Earthquake thrust-up floating preventive structure of manhole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain a conduit by eliminating thrust-up floating of a concrete manhole caused by swinging and liquefaction by an earthquake and damaging to a water conduit such as sewerage. <P>SOLUTION: This invention can eliminate the thrust-up floating of the manhole by the earthquake by arranging an outwardly horizontally overhanging thrust-up floating preventing fin on the whole periphery or partially in one to a plurality of stages on an outside surface of a vertical cylindrical part of the concrete manhole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a structure for preventing a concrete manhole from rising and rising due to an earthquake or the like.

Conventionally, as a concrete manhole, there exists Unexamined-Japanese-Patent No. 2000-110187. The gazette wraps an impermeable flexible band around the outer periphery of the joint part in order to prevent the ingress of groundwater and earth and sand when the joint part of the assembly type manhole is destroyed by an earthquake or the like. And fixing the lower part with a stainless steel belt.
JP 2000-11187 A

  However, concrete manholes including this gazette are used when a vertical inlay is piled up in open-cut soil, and after encountering an earthquake, etc. There have been many accidents in which manholes are pushed up and surfaced. In addition, there is a problem that a water pipe such as a sewer is broken by the rise of the concrete manhole.

  According to the present invention, a push-up fin is projected on the outer periphery of a vertical cylindrical portion of a concrete manhole to solve such a problem.

  In the present invention, since one or more fins are provided on the outer surface of the vertical cylindrical portion of the concrete manhole so as to protrude sideways and protrude in one or more stages, liquefaction phenomenon or the like may occur in the surrounding sediment due to an earthquake or the like. Even if it occurs, the concrete manhole is prevented from being lifted and lifted by the floating restraining action associated with the overhang of the fin. By embedding an insert nut in advance, there is an effect of facilitating the protrusion of the fin with the bolt.

  In the present invention, a horizontal protrusion-shaped fin for preventing levitating and floating is attached to the outer surface of a vertical cylindrical portion of a concrete manhole in one or more stages so that the concrete manhole can be moved even if shaking or liquefaction occurs due to an earthquake or the like. In order to prevent the levitation from rising due to the horizontal overhang in the ground.

  As shown in FIG. 1, a concrete manhole 1 having an inlay stacked shape is formed. The concrete manhole 1 of each layer is embedded and attached in advance with a steel collar 3 having an insert nut 2 having an inlet on the outer periphery at a predetermined position at the time of manufacture. The fin 4 for preventing levitation and floating is formed by an outwardly projecting fin portion 4b projecting horizontally from the lower end of the collar body 4a and a reinforcing plate 4c such as a triangle connecting the two, and is inserted into the inlet of the embedded insert nut 2 The bolt 5 is screwed and screwed and attached. 4 d is a connecting bolt and nut, 6 is a spigot joint, 7 is a fastening plate, and 8 is a joint hole of the water flow pipe 9.

  In the concrete manhole shown in FIG. 1, the lower stage is provided with an endless annular fin 4 as shown in FIG. 2, and the middle stage is shown in FIG. 2 or several pieces are attached symmetrically to the outer periphery, and the upper stage shows an embodiment in which steps are further provided as shown in FIG. 4, and an example in which fins 4 are also attached to the uppermost inclined wall. Show.

  FIG. 5 shows a steel collar 3 with an insert nut 2, which is used to prevent the steel collar 3 with an insert nut 2 from being lifted and lifted as shown in FIG. 6 in an existing concrete manhole or the like. The fin 4 is fixed to the anchor 10 and attached. A water-expandable rubber may be attached to the inner surface of the steel collar 3.

  Although the overhang width of the fin 4 for preventing the rising and rising is different depending on the size of the concrete manhole 1, it is about 15 to 30 cm.

  FIG. 7 shows an example in which the periphery of the fin 4 is formed in a straight line shape, and FIG. 8 shows an embodiment in which the fin 4 for raising and preventing floating is attached to the outer surface of the rectangular cylindrical concrete manhole 1a.

  As described above, the present invention can be easily installed in the existing manhole in addition to the newly installed concrete manhole to prevent the manhole from rising and rising due to an earthquake or the like and maintain the pipe line. Can do.

Sectional drawing which shows one example of the concrete manhole which gave the structure for preventing the rising and rising of the present invention Cross-sectional view of the part that has an endless ring around the fins Cross-sectional view of an example of mounting symmetrically in the same quarter division Partial vertical cross-sectional view showing an example of installation with steps above and below Plan view of steel collar and enlarged view of insert nut part Partial enlarged cross-sectional view showing an example of anchor bolt installation The top view which shows the example which formed the circumference of a fin in the shape of a straight line Plan view showing an example of a rectangular cylindrical concrete manhole

Explanation of symbols

1 is a concrete manhole 2 is an insert nut 3 is a steel collar 4 is a fin for raising and preventing rising 4a collar body 4b is a fin 4c is a reinforcing plate 4d is a bolt bolt for connection 5 is a bolt 6 is an inlay joint 7 is tight Plate 8 is a water pipe connection hole 9 is a water pipe

Claims (3)

  A structure for preventing ascent due to an earthquake in a manhole, characterized in that one or more fins are attached to the outer surface of a vertical cylindrical portion of a concrete manhole to prevent the levitation from rising due to an earthquake or the like.   The levitation preventing structure according to claim 1, wherein the levitation preventing fins are attached in an endless annular shape or divided into two or more parts, and are attached with a step difference between the upper and lower sides.   3. The structure for preventing levitation according to claim 1 or 2, wherein a steel collar with an insert nut for bolting and mounting a fin for preventing levitation at the time of manufacturing a concrete manhole is embedded and attached in advance to the outer periphery of the vertical cylindrical portion.

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