JP2004183383A - Manhole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manhole allowing the periphery of the constructed manhole to be efficiently compacted with backfilling soil. <P>SOLUTION: This manhole is provided at the origin of a pipe, at the change part of the direction, gradient and diameter of the pipe, at the formed part of step difference, at the meeting part of pipes, or the like. The side wall lower end of the manhole is equipped with grout holes passing through the wall. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a manhole that can efficiently backfill a constructed manhole with backfill soil.
[0002]
[Prior art]
The manhole is installed at the starting point and direction of the sewer, the slope, the place where the diameter of the sewer changes, the place where a step is formed, and the place where the sewer meets. In constructing a manhole, it is necessary to excavate to a sewer at a predetermined depth, and in order to prevent the collapse of the surrounding ground, a shaft is constructed by a retaining wall to protect the surrounding ground. The sewer manhole is composed of a bottom slab, a sewer mounting wall, a straight wall, a sloping wall, and a height adjusting ring, and is usually manufactured by casting concrete. In recent years, in order to make construction on site more efficient, split straight walls and sloping wall members and prepare assembly manholes manufactured in advance in factories, etc. The method of assembling these and constructing a manhole efficiently has been taken. Each member of the assembling manhole is made of reinforced concrete, and when building on site, a bottom slab is installed, and members are sequentially stacked on the bottom slab for construction.
[0003]
When the construction of the manhole is completed, backfilling is performed by putting backfill soil into the shaft. When backfilling, it is important to compact it sufficiently so that land subsidence does not occur after the construction is completed. As a method of backfilling, a method is generally adopted in which backfill soil is charged to a predetermined thickness, compacted sufficiently by a compacting machine, and then the next backfill soil is charged and compacted. Sandy soil is generally used as backfill soil.
[0004]
In the compaction method described above, the backfill soil is usually sandy soil, and the gap is formed by the engagement of the soil particles. The alignment cannot be broken, and it will be restored with a large gap. For this reason, there has been a problem that the ground surface sinks after a certain period of time has elapsed since the completion of the construction, or that the sewer buckles in the vicinity of the manhole attachment portion due to the sinking. For this reason, a water-tightening method is used in which water is applied to the backfill soil in combination with a compaction machine, and the engagement between the soil particles is broken by the water.
[0005]
[Problems to be solved by the invention]
By the above-mentioned water tightening method, it became possible to break the engagement between the soil particles, but the water flowing from the upper part penetrates to the lower part, becomes saturated under the backfill soil and the particles loosen, There is a problem in that the compacted backfill soil loses its compacting effect. For this reason, road settlements and the like are caused after restoration as in the past.
[0006]
Therefore, the present invention provides a manhole that can efficiently backfill the constructed manhole area with backfill soil.
[0007]
[Means for Solving the Problems]
That is, the present invention is a manhole provided at the starting point and direction of a sewer, a slope, a place where a sewer diameter changes, a place where a step occurs, a place where a sewer meets, and the like.
The manhole is characterized in that a grout hole is provided at the lower end of the side wall of the manhole so as to penetrate the wall surface.
[0008]
The manhole is generally made of a concrete member, and may be manufactured in place or may be a factory-manufactured manhole. The grout hole provided at the lower end of the side wall of the manhole penetrates the wall surface. By embedding an internally threaded socket or the like in the grout hole, a valve can be installed from inside the manhole. By installing a filter on the outer wall surface of the grout hole, intrusion of earth and sand into the manhole is prevented.
[0009]
The number of grout holes may be changed depending on the diameter and height of the manhole, and usually the grout holes are provided at two opposing positions.
[0010]
A drain pump is installed in the manhole, and the water that has infiltrated from the surface of the backfill soil is drained from the grout hole and discharged to the ground.
[0011]
After compaction by water fastening is completed, mortar or resin material can be injected into the backfill soil using grout holes to improve the ground around the manhole.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view illustrating a manhole according to the present invention. The bottom plate 5 is installed at the junction of the laid conduits 13, and the culvert mounting wall 1 is installed thereon by connecting the mounting holes 7 of the culvert mounting wall 1 to the conduit 13. Further, the straight wall 2, the sloping wall 3, and the manhole cover 4 are stacked one above the other to construct a manhole at the same height as the road surface. The surroundings of the manhole are protected by a retaining wall 11 made of steel sheet pile or the like so that the surrounding ground does not collapse.
[0013]
When the construction of the manhole is completed, a valve 10 is attached to the grout hole 6 provided on the sewer attachment wall 1, and a drainage pump 15 is installed on the bottom plate 5 in the manhole. Then, backfill soil 12 of a predetermined thickness is put into a shaft around the manhole, and compacted by a compacting machine (not shown). In parallel with the compaction by the compacting machine, water is applied to the backfill soil 12 from the ground with a water pipe 14 such as a hose to perform water compaction. The water applied to the backfill soil 12 penetrates through the backfill soil 12, moves downward, and enters the manhole through the grout hole 6 provided at the lower end of the conduit wall 1. At this time, the valve 10 attached to the grout hole 6 is open. The water that has entered the manhole is discharged to the ground via a drain pipe 16 by operating a drain pump 15. The discharged water can be reused for water filling again.
[0014]
FIG. 2 is a sectional view showing the sewer mounting wall 1 in detail. A mounting hole 7 is provided in the middle of the wall surface in accordance with the position of the sewer 13. A grout hole 6 is provided at the lower end of the wall surface at a position facing the grout hole 6. In the present embodiment, the assembly manhole has been described. However, it is also possible to use a method in which concrete is cast and constructed on site. In this case, the pipe 13 and the grout hole 6 may be cut out in advance using a mold material. Although the grout hole 6 is illustrated in two places in the present embodiment, it can be increased or decreased according to the diameter of the manhole or the like.
[0015]
FIG. 3 is a cross-sectional view illustrating the grout hole 6 in detail. In the grout hole 6, a fixture 8 such as a socket provided with an internal thread is installed also as a form material. A filter 9 is provided on the outer surface of the grout hole 6 so that the backfill soil 12 does not enter the manhole. A valve 10 is mounted inside the grout hole 6 to remove water saturated in the backfill soil 12. When the compaction of the backfill soil 12 by water-tightening is completed, the valve 10 is removed, a water-stopping treatment is applied to the recessed portion to finish the surface, and the backfill of the manhole is completed.
[0016]
When the ground improvement around the manhole is performed after water-tightening, an injection hose is connected to the valve 10 and mortar or resin material is injected into the backfill soil 12 around the manhole to improve the ground. The determination as to whether the injection material such as mortar has gelled may be made by opening the valve 10.
[0017]
【The invention's effect】
As described above, the manhole of the present invention makes it possible to efficiently and reliably compact the backfill soil by collecting the water that has been tightened around the constructed manhole from the lower end of the manhole. And the sewer at the connection is no longer damaged.
[0018]
[Brief description of the drawings]
FIG. 1 is a sectional view illustrating a manhole according to the present invention.
FIG. 2 is a sectional view illustrating a sewer mounting wall in detail.
FIG. 3 is a sectional view illustrating a grout hole in detail.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Conduit mounting wall 2 Straight wall 3 Sloping wall 4 Manhole cover 5 Bottom plate 6 Grout hole 7 Mounting hole 8 Fixture 9 Filter 10 Valve 11 Retaining wall 12 Backfill soil 13 Conduit 14 Water pipe 15 Drain pump 16 Drain pipe

Claims (1)

Manholes provided at the starting point and direction of the sewer, the gradient, the place where the diameter of the sewer changes, the place where a step occurs, the place where the sewer meets, etc.
A manhole, characterized in that a grout hole is provided at the lower end of the side wall of the manhole so as to penetrate the wall.

Images