JP5801635B2 - Manhole and connection main construction method. - Google Patents

Description

  The present invention relates to a method for constructing manholes and connection mains.

In urban sewers, sewage generated at each house is sent to the sewage treatment plant via the sewage basins, branch pipes, main manholes, and mains.
Among these, manholes that connect branch pipes, and mains that lead sewage to sewage treatment plants via manholes, will be developed in advance as a key infrastructure during urban development.
The present invention relates to a manhole as the basic infrastructure and a main construction method for connecting the manholes.

JP 2004-169542 A.

Conventionally, there have been the following problems when constructing a main that is deep to some extent. Here, “somewhat deep” assumes that the excavation method cannot be adopted and the propulsion method is adopted.
<1> First, at the place where the manhole is installed, a shaft is constructed by protecting it with a sheet pile, etc., and each main shaft is started and a main pipe is constructed by a propulsion method as a reaching shaft.
<2> By repeating such steps, the shafts are connected by the propulsion method, and the manhole is constructed in such a manner that the propulsion pipe is wound around each shaft.
<3> However, in the conventional method as described above, although the expensive propulsion method is adopted, the construction section in the propulsion method is determined by the manhole interval, and the construction extension takes in the branch pipe. For this reason, the short distance for this was uneconomical at most about 50 m.
<4> As described above, the propulsion method was originally economical in construction for a long distance of 300 m or more, but was able to perform only a short distance construction, and did not perform its original function.
<5> Furthermore, in the construction of shafts, the method of placing a sheet pile is economical because it can recover the earth retaining material, but it is necessary to press-fit the sheet pile individually and to support the beam inside. There is a problem that the construction period becomes longer compared to the mud drilling steel pipe press-fitting method, in which the steel pipes are press-fitted in a lump and the support work is unnecessary .
<6> In the type in which the steel pipe is press-fitted, the steel pipe cannot be pulled out by placing the underwater concrete, and it must be buried and there is a problem that the economy is deteriorated .

In order to solve the problems as described above, the construction method of the manhole and connection main pipe of the present invention is a method of press-fitting a steel pipe into the ground, excavating muddy water inside, placing concrete at the bottom, and precasting on it. A manhole is constructed by inserting a frame, and fluidized soil is filled in the space between the manhole and the inside of the steel pipe, and the steel pipe is pulled out in parallel with this filling, thus constructing manholes at a plurality of locations, It is characterized by constructing a continuous connection main through a plurality of manholes by the propulsion method.

Since the construction method of the manhole and connection main of the present invention is as described above, the following effects can be obtained.
<1> A single long-distance propulsion tunnel can penetrate and penetrate a number of manholes in sequence, so that a sewer network can be constructed extremely economically.
<2> In the propulsion method, it was found that long-distance propulsion exceeding 300 m was economical, but as described above, the propulsion method was conventionally only between manholes installed at short intervals for taking in branch pipes. It was uneconomical to be connected by. In this respect, the construction method of the present invention can continuously shoot a large number of manholes with a single propulsion tunnel, enabling long-distance propulsion and not only being economical, but also shortening the construction period and minimizing construction congestion. Can also be planned.
<3> Because this is a method Yuku pull out slowly steel pipe with increasing filling of the fluidizing treated soil, the material to be filled into the inner side surface portion of the steel pipe is fluidized treated soil rather than concrete, promotion later This is because the tunnel can be easily penetrated and economical long-distance propulsion can be realized.
<4> Compared with construction methods using piles such as sheet piles, the construction period is remarkably improved by excavating steel pipes that can be rapidly constructed, filling and backfilling with fluidized soil, and precast manholes. It can be shortened.

Explanatory drawing in construction of the manhole of this invention. Explanatory drawing of the order which builds a manhole. Illustration of the order of building manholes Illustration of the order of building manholes Illustration of the order of building manholes Illustration of the order of building manholes Illustration of the order of building manholes Explanatory drawing of the state where a large number of completed manholes were shot through one propulsion tunnel and connected.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<1> Press fitting and excavation of steel pipes. (Figure 2)
A steel pipe 2 having an inner diameter larger than the outer diameter of a newly installed manhole 1 is press-fitted into the ground. Such press-fitting devices are known and can be used anywhere.
Excavation is performed from the ground while supplying muddy water to the inside of the pressed steel pipe 2. Therefore, ground disturbance such as boiling can be minimized.

<2> Placement of foundation concrete. (Figure 3)
After excavating to the planned hole bottom, foundation concrete 21 is placed on the bottom with underwater concrete.
The foundation concrete 21 is placed in water by a publicly known method using a tremy pipe and pouring concrete from the ground.

<3> Stack of precast frames. (Figure 1)
The precast manhole 1 is constructed by putting the precast frames 11 in a lump or sequentially stacking them.
The precast frame 11 is, for example, a rectangular and circular concrete cylinder in plan view, and has an uneven joint formed on the upper and lower end surfaces.
Further, a guide material 12 is provided around the precast frame 11 in the radial direction.
The protruding dimension of the guide material 12 is equal to the distance between the outer surface of the precast frame 11 and the inner surface of the steel pipe 2.
Then, when the precast frame 11 is suspended, a sliding material such as a roller of the guide material 12 protruding in the radial direction slides down on the inner surface of the steel pipe 2, so that when the precast frame 11 is suspended in the muddy water, the steel pipe 2 can be accurately installed at the center position.

<4> Bottom precast frame.
The lowermost precast frame 11 has a fixing column 13 protruding from the lower part. This support | pillar 13 is comprised with short H-shaped steel.
Further, on the side surface, a through window 14 is provided on the opposite surface.
This penetration window 14 is a hole for the propulsion device 3 of the propulsion method described later to penetrate.
Until the propulsion device 3 passes through the through window 14, the window is closed with a plate made of FRP or the like that easily breaks, and the intrusion into the muddy water and fluidized soil is prevented.

<5> Hanging the precast frame. (Fig. 4)
First, the lowermost precast frame 11 is suspended before the foundation concrete 21 at the bottom is hardened.
Then, the fixing column 13 on the lower surface of the precast frame 11 can enter the base concrete 21 at the bottom and be fixed.
As a result, the horizontal displacement of the precast frame 11 can be prevented even when the steel pipe 2 described later is pulled out.
On the lowermost precast frame 11, the factory-produced precast frame 11 is sequentially suspended and stacked.
This work is also performed in muddy water.

<6> Filling with fluidized soil. (Fig. 5)
The manholes 1 are sequentially completed by stacking the precast frames 11, but in parallel to the stacking, the manholes 1 are filled around the manholes 1 with a low-strength plastic body such as fluidized soil 4 using tremy tubes. .
The mud overflows from the upper end of the steel pipe 2 to the outside according to the filling of the low-strength plastic material such as the fluidized soil 4.

<7> Pulling out the steel pipe. (Fig. 6)
The steel pipe 2 is gradually pulled out as the uppermost surface of the fluidized soil 4 is filled.
Since the material filled in the steel pipe 2 is not the concrete but the fluidized soil 4, the steel pipe 2 can be easily pulled out without being constrained and can be recovered economically.
Further, since the fluidized soil 4 is filled in the trace of the steel pipe 2 being pulled out, it is possible to prevent the boiling collapse and pull out the safe steel pipe 2.
In the above process, the precast frame has been described as a circular concrete cylinder, but it may be made of steel or a steel pipe.
Even in the case of a steel pipe, it is the same that a through window through which an excavator to be described later passes is necessary.

<8> Completion of manhole. (Fig. 7)
In this way, the steel pipe 2 is collected, and a new manhole 1 filled with the fluidized soil 4 is completed.
Manholes 1 are newly established at a plurality of locations through the same process.
In that case, according to the construction method of the present invention, even when the distance between the manhole 1 and the manhole 1 is short, a plurality of manholes 1 are shot out by the propulsion construction method and connected by a long connection main.
Therefore, the manholes 1 can be connected economically by one continuous propulsion tunnel, that is, a connecting main.
Thus, the manhole 1 of the present invention can be newly installed at a free position without considering the distance of the main pipe to be connected.

<9> Promotion method. (Fig. 8)
First, the propulsion shaft 5 for starting the propulsion method is constructed.
The shaft 5 is provided with a main pushing jack 51, a propulsion base 52, a bearing plate 53, and the like.
With the main push jack 51, the leading propulsion device 3 and the subsequent propulsion pipe 31 are sequentially press-fitted into the ground, and a continuous propulsion tunnel 32 is constructed.
Equipment and methods related to the propulsion method are well known.

<10> Manhole group penetration. (Fig. 8)
The propulsion device 3 at the tip of the propulsion tunnel 32 approaches the manhole 1, but since the fluidized soil 4 is only formed around the manhole 1, the propulsion device 3 can easily reach the manhole 1. it can.
When the propulsion device 3 reaches the manhole 1, the propulsion device 3 enters the manhole 1 through the through-hole 14 at the bottom of the manhole 1.
Since the through-hole 14 of the manhole 1 is only closed by a plate material that is easily broken, it can be easily entered.
At this time, if the bottom of the manhole 1 is filled with mud beforehand, it is possible to prevent the occurrence of trouble such as mud when entering.
Further, when the propulsion unit 3 is pressurized and propelled, the propulsion unit 3 passes through the manhole 1 and exits through the opposite through window 14 into the ground.
By repeating the above operations, a large number of manholes 1 can be sequentially penetrated and ejected by one long-distance propulsion tunnel 32.
Finally, the propulsion device 3 reaches the reaching shaft and collects it.

<11> Removal of unnecessary tubes.
Since the propulsion pipe 31 located inside the manhole 1 is unnecessary, it is disassembled and removed.
Thereafter, an inner surface finish such as a water stop treatment of the attachment portion between the manhole 1 and the propulsion pipe 31 is performed.
In this way, a sewage network in which a long extension of the propulsion tunnel 32 constituted by the propulsion pipe 3 is used as a connecting main pipe to connect a plurality of manholes 1 group is completed.

1: Manhole 11: Precast frame 14: Through window 2: Steel pipe 3: Propeller 31: Propulsion pipe 32: Propulsion tunnel 4: Fluidized soil 5: Propulsion shaft

Claims (3)

Press the steel pipe into the ground,
Drilling mud inside,
Put concrete on the bottom,
A manhole is built by putting a precast frame on top of it,
Fill the space between the manhole and the inside of the steel pipe with fluidized soil .
Pull the steel pipe in parallel with this filling,
In this way, manholes are built at multiple locations,
After that, through a plurality of manholes by the propulsion method, a continuous connection main is constructed.
Manhole and connection main construction method. The precast frame at the bottom is
It has a through-hole that has a side opening, and a fixing column that protrudes from the bottom.
Before the concrete is hardened, the lowermost precast frame is thrown on the concrete, and the fixing column enters and is fixed in the concrete .
The manhole and connection main construction method according to claim 1. The precast frame has a guide material projecting radially around it,
Upon installation in steel pipe precast frame, guide member is configured to slide the steel pipe inner surface,
While leaving the guide material, filling the fluidized soil and pulling out the steel pipe,
The manhole and connection main construction method according to claim 1.

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