JPH09125394A - Backfilling technique for burying ditch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To utilize residual soil by constructing bank bodies with a slurry and highly viscous fluidization treated soil comprising mainly residual soil and back filling a slurry and low viscous fluidization treated soil comprising mainly residual soil between the bank bodies. SOLUTION: A burying ditch 1 is excavated, and a buried matter 3 such as Hume pipe is laid down on a laid sand 2 formed at the bottom part of the burying ditch 1. Next a slurry and highly viscous fluidization treated soil comprising mainly residual soil is sprayed or deposited by a mold work method in the excavation advancing direction of the burying ditch 1 so as to construct a bank body 4. Also a slurry and low viscous fluidization treated soil as backfilling material 5 comprising residual soil is back filled in the burying ditch 1 divided by the bank bodies 4 and 4a. In this case, a buoyancy F generated on the buried matter 3 is cancelled by the self gravities W and W of the bank bodies 4 and 4a so as to stop their rise. The same procedure is repeated so as to bury the buried matter. Thus residual soil for construction can be utilized effectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burying method for burying water and sewer pipes and various cables, and more specifically, burying using residual soil which is industrial waste generated from a construction site.
This is related to the backfilling method for buried trenches.

[0002]

2. Description of the Related Art Most of the residual soil generated at civil engineering construction sites is discarded, but the disposal of the residual soil has become a serious social problem due to the shortage of the disposal site. As a solution to this problem, it has been attempted to slurry this type of residual soil and use it for landfilling the trench. Specifically, the residual soil and solidifying material (such as cement) are mixed with water to form a slurry, and these slurry-like materials (hereinafter referred to as "fluidized soil").
Is used as a backfill material for the groove.

[0003]

There are the following points to be improved in the method of utilizing the fluidized soil as the backfill material. <B> Since fluidized soil has a very high water content, it causes buoyancy in buried objects such as pipes. Therefore, it is necessary to separately take measures against the buoyancy of the buried object, and there is currently no suitable measure against buoyancy. <B> Since the fluidized soil has a low viscosity, it is necessary to form a sandbag or a weir in the middle of the groove to prevent the fluidized soil from flowing out, and it takes a lot of work to form the sandbag or the weir. <C> Most of the fluidized soil is water and the amount of soil used is small. Therefore, the reuse rate of the remaining soil is low.

The present invention has been made in view of the above points, and the purpose thereof is to effectively use the remaining soil,
Moreover, it is to provide a backfill technology for buried trenches that does not require special measures for buoyancy measures for buried objects and measures for preventing outflow of fluidized soil.

[0005]

According to the present invention, in a backfilling method of a buried groove in which a buried object is laid in a buried groove and then backfilled with a backfill material, a slurry-like highly viscous material mainly composed of residual soil is used. The fluidized soil is cast into a part of the embankment to construct a dam body, and the slurry-like low-viscosity fluidized soil consisting mainly of residual soil is embedded in the embankment defined by the embankment. This is a method for backfilling a buried groove, which is characterized by filling as a return material.
Furthermore, the present invention is a backfilling method of a buried groove to be backfilled with a backfill material after laying a buried object in the buried groove, a step of excavating the buried groove, a step of laying the buried object in the buried groove, and a residual soil. The step of constructing a dam body by placing a slurry-like highly viscous fluidized soil mainly composed of the above in a part of the buried groove, and a slurry-like low-viscosity fluidized soil mainly composed of residual soil A backfilling method for a buried trench, characterized by repeating a step of filling as a backfill material in a buried trench defined by a bank body. Further, the present invention is the backfilling method for an embedding groove, characterized in that the highly viscous fluidized soil is a kneaded material of a sludge and a solidifying material whose specific gravity is adjusted with the residual soil. Further, the present invention is the backfilling method for a buried groove, wherein the low-viscosity fluidized soil is a kneaded product of a clay-like material and a solidifying material whose specific gravity is adjusted with the residual soil.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 of the present invention will be described below with reference to the drawings.

<B> Fluidized soil First, in the present invention, fluidized soil having different viscosities is used as a backfill material, and as a dam for controlling outflow of fluidized soil,
Used as a buoyancy resistance material for buried objects. The fluidized soil is a slurry-like material obtained by kneading a mud-like material whose specific gravity has been adjusted uniformly, and a treated soil such as residual soil generated at a construction site, or a solidifying material such as cement added to these materials. It means a solidifying slurry.

<B> Mud The mud, which is a constituent of fluidized soil, contains mud containing clay, silt, bentonite, etc. and water as a compounding element, and uniformly adjusts the specific gravity of these mixtures. Means muddy water. The specific gravity of the mud is adjusted by the mixing ratio of mud and water. In other words, the treated soil generated at the site not only serves as a compounding ingredient for the mud, but also as a fluidizing-processed ingredient. Specifically, in addition to the residual soil generated at the construction site, it was recovered in an uncured state. It contains old mud. Regarding the preparation of mud and fluidized soil, the present inventor previously filed Japanese Patent Application Laid-Open No. 5-182.
Since it is disclosed in Japanese Patent Publication No. 108, description thereof will be omitted.

[0009]

Next, a method of burying a buried object using the fluidized soil will be described.

<B> Excavation of trench and laying of buried object (Fig. 2) The buried trench 1 is excavated by a well-known excavator, and the buried object such as a fume pipe is placed on the sand 2 formed at the bottom of the buried trench 1. 3 is laid. When the buried object 3 is laid, a sufficient water stop is applied to the connection portion with the end of the buried object 3a that was buried in advance.

<B> Construction of Embankment (FIGS. 2 and 3) When the embedding of the buried object 3 is completed, the embankment 4 is constructed on the side of the embedding groove 1 in the excavation direction. The levee body 4 is constructed by dividing the fluidized soil described above having a high viscosity (fluidized soil having a low specific gravity) into a plurality of layers or continuously arranging it in a mountain shape. The fluidized soil used for constructing the bank body 4 may be constructed by a spraying method or a formwork method, and at least have a viscosity that allows it to be self-supporting immediately after it is placed. The poured fluidized soil covers the outer periphery of the buried object 3 near the end portion thereof, and is placed in close contact with the unevenness of the wall surface of the buried groove 1 to finally define the buried groove 1 into two. . As the fluidized soil that constitutes the bank 4, for example, the specific gravity of the mud is about 1.05 to 1.10, the mixing ratio of the mud is about 0.2, and the flow value is 80.
A thing of ~ 120 mm can be used. Reference numeral 2a on the right side of the drawing in FIG. 2 is a hardened bank constructed in the previous span.

<C> Backfilling (FIG. 1) After the construction of the dam body 4 is completed, the fluidized soil of low viscosity (high specific gravity) is backfilled in the buried groove 1 defined by the dam bodies 4 and 4a. Fill as material 5. The backfill material 5 is prevented from flowing out by the bank 4 that defines the buried groove 1, is filled in every corner of the buried groove 1, and gradually increases its liquid level. As the liquid level of the backfill material 5 rises, the upward buoyancy F generated in the buried object 3 also gradually increases. This buoyancy F is canceled by the downward weights W, W of the levee bodies 4, 4a placed on both ends of the buried object 3,
The embedded object 3 is prevented from floating. That is, the bank body 4 is the backfill material 5
Not only does it function as a weir that prevents the outflow of water, but also as a buoyancy counter member for the buried object 3. As the fluidized soil 5 that constitutes the backfill material 5, for example, the specific gravity of the mud is in the range of 1.05 to 1.15, and the mixing ratio of the mud is 0.2 to 0.4. A value of 100 to 140 mm can be used. Similarly, the buried object 3 is buried while repeating the excavation process of the buried trench 1, the laying process of the buried object 3, the building process of the dam body 4, and the backfilling process. It is necessary to select an appropriate specific gravity for the fluidized soil that is actually used, depending on the nature of the soil generated at the civil engineering construction site.

[0013]

Embodiment 2 FIG. 4 shows another embodiment in which the bank body 4 and the backfill material 5 are hierarchically constructed. Explaining the construction method, for example, after constructing the first divided bank body 4b,
After filling the first backfill material 5b to the height of the divided bank body 4b, and then adding the second divided bank body 4c to the top of the first divided bank body 4b, the second backwater material 5b is added to the upper portion of the first backfill material 5b. The backfill material 5c is filled. Similarly, the third divided dike 4d is added to the top of the second divided dike 4b in the same manner, and the dike 4 up to a predetermined height.
The backfill material 5 and the backfill material 5 are constructed in several stages.

[0014]

According to the present invention, the following effects can be obtained. <B> By fluidizing the remaining construction soil, which has been a problem to be treated, it can be effectively used as a backfill material. <B> The levee body and the backfill material can be constructed using the same type of fluidized soil only with different specific gravities. <C> Since the embankment body and the backfill material are the same type of fluidized soil, they are compatible with each other and high integrity can be secured after construction. <D> The levee body not only functions as a shut-off material for the backfill material, but also functions as a weight member against the buoyancy generated in the buried object, and does not require additional buoyancy countermeasure work for the buried object. <E> Since the backfill material uses fluidized soil with low viscosity,
It is possible to fill every corner of the buried groove, and good backfilling is possible without generating voids inside.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram when filling a backfill material.

[Fig. 2] An explanatory view of the process of constructing a dam body

[Fig. 3] Cross-sectional view of the levee body

FIG. 4 is an explanatory diagram according to a second embodiment of backfilling hierarchically.

[Explanation of symbols]

 1 ... buried groove 2 ... set sand 3 ... buried material 4 ... dam body (fluidized soil with high viscosity) 5 ... backfill material (fluidized soil with low viscosity)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noriyuki Mori 1 Asahi, Tsukuba City, Ibaraki Prefecture Asahi Civil Engineering Institute (72) Inventor Goro Kuno 1-6-34 Konan, Minato-ku, Tokyo Tokyo Nissan Port Building Japan Institute of Construction Management Central Institute of Technology (72) Inventor Kihei Takeda 1-6-34 Konan, Minato-ku, Tokyo Tokyo Nissan Port Building Japan Institute of Construction Management Central Institute of Technology

Claims (4)

[Claims] 1. A method of backfilling a buried groove, which comprises burying a buried object in a buried groove and then backfilling it with a backfill material, wherein a slurry-like highly viscous fluidized soil mainly consisting of residual soil is used as one of the buried grooves. It is characterized in that a dam body is constructed by being cast in a part of the dam, and a slurry-like low-viscosity fluidized soil consisting mainly of residual soil is filled as a backfill material in the embedding groove defined by the dam body. Yes, the method of backfilling the buried trench. 2. A method of backfilling a buried groove, which comprises burying an buried object in a buried groove and then backfilling it with a backfill material, the step of excavating the buried groove, and the step of laying the buried object in the buried groove. Slurry-like highly viscous fluidized soil mainly composed of residual soil is placed in a part of the buried trench to construct a dam body, and slurry-like low-viscosity fluidized soil mainly composed of residual soil is used. A method for backfilling a buried groove, wherein a step of filling the buried groove defined by the bank as a backfill material is repeated. 3. The method for backfilling a buried groove according to claim 1 or 2, wherein the highly viscous fluidized soil is a kneaded product of a mud and a solidifying material whose specific gravity is adjusted with the residual soil. . 4. The method for backfilling a buried groove according to claim 1 or 2, wherein the low-viscosity fluidized soil is a kneaded material of mud and a solidifying material whose specific gravity is adjusted with the residual soil. .