JP5973213B2 - Method of embedding pipes with fluidized soil - Google Patents

Description

  The present invention relates to a method for embedding a pipe used in a pipeline or the like with fluidized soil.

Conventionally, as a method of burying pipe bodies such as pipelines, a buried groove is provided on the ground surface, a pipe body is installed at the bottom of the buried groove, and then buried using fluidized soil. It has been broken.
Since the fluidized soil is excellent in fluidity, it will reach the periphery of the pipe sufficiently compared to soil and improved soil, and the pipe and the excavation groove are filled without any gaps. There is an advantage that the body can be stabilized.

However, as shown in FIGS. 3 and 4, when the fluidized soil a is used, the fluidized soil a behaves as a liquid immediately after placement, so that buoyancy is applied to the tube b so that the tube b is A new problem arises.
It is considered that the tube b moves from the set position once the tube b rises. In order to return the tube b to the set position, the fluidized soil a for burial is removed, and the tube b is returned to the set position. Body b must be set up again.

  As a method of preventing the tube body from floating, for example, as in Patent Document 1, a method of preventing the tube body from floating by fixing the tube body with an anchor bolt fixed to the bottom of the excavation groove; As described above, there is known a method of fixing a tubular fixture to a sheet pile installed on the side of an excavation groove and preventing the floating of the tubular body by this fixture.

JP 7-317959 A JP-A-6-249365

  However, in the prior art described in Patent Document 1, Patent Document 2, etc., a complicated instrument such as an anchor bolt or a fixture is required, and the anchor bolt is fixed to the bottom of the excavation groove, or on the side of the excavation groove. There is also a problem that a work of laying a pipe body becomes complicated due to the work of installing a sheet pile at the part.

As a method that does not use the fixing device as described above, a method of placing fluidized soil in stages is also conceivable.
In other words, when placing the fluidized soil, the fluidized soil is suspended before the buoyancy acting on the tube becomes greater than the weight of the tube itself, and the fluidized soil solidifies and floats. This is a method of restarting the placement of the fluidized soil again after no longer occurs.
Even in such a burying method, there is a problem that the pipe body is lifted by the buoyancy of the fluidized soil itself and water when rain, inflow of groundwater, or the like occurs immediately after the fluidized soil is placed.

  The present invention, which has been made with respect to such problems of the prior art, is a tube burying method that can prevent the tube from floating by a relatively simple method when burying the tube using fluidized soil. The issue is to provide.

In order to solve the above-described problems, the method of burying a pipe body with fluidized soil according to the present invention is a method of burying a pipe body in fluidized soil in a pipe buried groove, and burying a pipe body After laying in the ditch, when the fluidized soil is placed, the fluidized soil is placed at a height so that the buoyancy acting on the tube does not become larger than its own weight. perform pouring of treated soil, before fluidization treated soil is solidified, performed by forming a Karimizo the left and right surfaces of the fluidizing treated soil of the tubular body, and configured to embed the tube with fluidized treated soil It is characterized by this.

Since the pipe embedding method using the fluidized soil of the present invention is as described above, the following effects can be obtained.
<1> The water that has flowed into the surface of the fluidized soil by removing the water on the surface of the fluidized soil by simply forming a temporary groove on the surface of the fluidized soil in the first step. It is possible to suppress buoyancy to the tube due to the above.
<2> Therefore, when rainfall or groundwater flows into the buried groove, it can be discharged through the temporary groove, and the occurrence of buoyancy of the tubular body can be prevented.
<3> At the same time, in each step, breathing water generated on the surface of the fluidized soil can be eliminated, so that the development of the strength of the fluidized soil can be accelerated.

Explanatory drawing of the Example of the embedding method of the pipe body by the fluidization processing soil of this invention. Explanatory drawing of another Example. Explanatory drawing of the example of the embedding method of the conventional pipe body Sectional drawing of FIG.

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

<1> Explanation of fluidized soil The method of the present invention is a method for embedding a pipe body in fluidized soil 1.
The fluidized soil 1 used there is "adjusted muddy water", "construction generated soil", "solidification material", and these are mixed in an appropriate composition to obtain a fluidized state suitable for the application, either directly or pumped. It is set up by pumping.
Since this fluidized soil 1 is a well-known reliable material that has many literatures and construction results and is organized by an association, a detailed description thereof will be omitted.

<2> Pre-process First, the tube burial groove 2 for burying the tube body in the ground is excavated, and a foundation for laying the tube body 3 is formed at the bottom of the groove with grit stone or discarded concrete.
Then, a pipe body 3 such as a pipeline is laid on the base.
Hereinafter, the steps after this step will be described.

<3> First Embedding Step The fluidized soil 1 of the first step is placed around the tube 3 laid at the bottom of the tube buried groove 2.
In this embedding process, the placement height of the fluidized soil 1 is set so that the buoyancy acting on the tube body 3 does not become larger than the dead weight of the tube body 3, and the fluidized soil 1 is driven according to the setting. Set up.
Thereafter, it is confirmed that a predetermined strength is developed in the fluidized soil 1 that has been placed.
The setting of the placement height can be easily determined because the specific gravity of the fluidized soil 1, the volume and weight of the tube 3 are known.

<4> First-stage temporary groove Before the fluidized soil 1 in the first step is solidified, first-stage temporary grooves 4 are formed on the surfaces of the right and left fluidized soil 1 of the tube 3.
The temporary groove 4 is provided on the surface of the fluidized soil 1 by, for example, preparing a bowl having a U-shaped cross-section with a half of a cylinder and pressing it from above the fluidized soil 1 that has not yet solidified. By doing so, it can be molded.
Or the perforated pipe body 3 which opened many holes can also be pressed against the surface of the fluidization processing soil 1, and can be installed.
Moreover, since the surface of the fluidized soil 1 is divided into left and right by the pipe 3 to be embedded, the temporary grooves 4 need to be installed on the left and right of the pipe 3. The temporary grooves 4 installed on the left and right sides of the tube body 3 may be installed substantially parallel to the tube body 3.
Since the pipe body 3 to be embedded is given a natural gradient from the upstream side toward the downstream side, the temporary groove 4 formed on the surface of the fluidized soil 1 also has the same natural gradient.
Moreover, when installing the pipe body 3 substantially horizontally, it is good to give a gentle gradient to the surface of the fluidization-treated soil 1 and make the temporary groove 4 have a gentle gradient.
In any case, the water that has flowed into the temporary groove 4 flows down the temporary groove 4 and is guided to the pothole described later.
The water on the surface of the fluidized soil 1 may be inclined in the transverse direction so that the water on the surface of the fluidized soil 1 flows into the temporary grooves 4.
Furthermore, if a branch-like groove is attached to the temporary groove 4 so that water flows from the branch-like groove to the temporary groove 4, water does not accumulate on the surface even when the surface of the fluidized soil 1 is widened. Can be.

<5> When there is rain As described above, in the first embedding step, the placement height of the fluidized soil 1 is set so that the buoyancy acting on the tube body 3 does not become larger than the weight of the tube body 3 itself. The fluidized soil 1 is placed according to the set height.
Therefore, the tube body 3 is not lifted by the buoyancy of the fluidized soil 1, and the provisional groove 4 is not usually required.
However, if there is rainfall in the buried trench 2, surface water inflow due to rainfall, inflow of groundwater, etc., problems arise.
Normally, the pipe body 3 is installed by cutting the buried groove 2 on a low ground, so that a large amount of water concentrates in the buried groove 2 from a wide area.
Then, water of several centimeters to several tens of centimeters immediately accumulates on the surface of the fluidized soil 1 in the first step.
The water on the surface of the fluidized soil 1 and the fluidized soil 1 itself act as buoyancy on the tube body 3, and the tube body 3 floats up to the fluidized soil 1 attached to the periphery of the tube body 3. I will raise you.
However, in the method of the present invention, since the temporary grooves 4 are formed on the surface of the fluidized soil 1, the water collected by the rain can be quickly discharged in the downstream direction.
Then, if a pot place where the fluidized soil 1 does not flow in is provided in a part of the buried groove 2 and surrounded by a sandbag as will be described later, the water collects in the pot place and drains from there with a submersible pump. be able to.
Of course, it is natural that the height of the bottom of the pot is set lower than the temporary groove 4.
The above problem can be solved by drainage from the temporary groove 4 not only at the time of raining but also at a site where the amount of groundwater spring is large.

<6> Second Embedding Step After the fluidized soil 1 of the first step is solidified and buoyancy is no longer generated, the dredging and the perforated tube 3 used for the first stage temporary groove 4 are removed, and the second step The fluidized soil 1 is placed.
Also in this second burying step, the placement height of the fluidized soil 1 is set so that the buoyancy acting on the tube body 3 does not become larger than the dead weight of the tube body 3, and the fluidized soil 1 is set to the set height. To cast.
Thereafter, it is confirmed that a predetermined strength is developed in the fluidized soil 1 that has been placed.

<7> Repeating the process By repeating the above steps, the tube body 3 is not lifted, and even if rainwater is concentrated in the tube buried groove 2 due to rain, the tube body 3 is not lifted up safely and reliably. The pipe body 3 can be embedded with the fluidized soil 1.

<8> Drainage from Kamaba A part of the buried groove 2 is surrounded by a sandbag or the like to form a kamaba where the fluidized soil 1 does not flow.
This pot hall is formed on the extension of the temporary groove 4 and has a volume capable of accommodating the submersible pump.
Then, since the water flowing down from the temporary groove 4 can be drained to the outside of the buried groove 2 by a submersible pump, the tube body 3 does not float due to rain water or the like.

<9> Other embodiment (FIG. 2)
Before excavating the tubular body burying groove 2, piles 5 and sheet piles are formed on both sides of the buried groove 2, and the temporary body 4 is formed in each step even when the tubular body 3 is buried therein. A similar effect can be obtained.

1: Fluidized soil 2: Tube buried groove 3: Tube 4: Temporary groove 5: Yamadome

Claims (2)

It is a method of burying a pipe body with fluidized soil in a pipe body burying groove,
After laying the tube in the buried groove,
When placing the fluidized soil,
Set the casting height of the fluidized soil so that the buoyancy acting on the tube does not become larger than the weight of the tube, and cast the fluidized soil.
Before the fluidized soil solidifies,
Performed to form a Karimizo the left and right surfaces of the fluidizing treated soil of the tube,
Embed the pipe with fluidized soil,
A method of burying pipes with fluidized soil. The method of claim 1, wherein
A pot hall that can store a submersible pump is formed in the buried groove,
Drain the water flowing down from the temporary groove with a submersible pump,
A method for embedding a pipe body using fluidized soil according to claim 1.

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