JP2004125100A

JP2004125100A - Construction method for burying pipe

Info

Publication number: JP2004125100A
Application number: JP2002291746A
Authority: JP
Inventors: Atsushi Matsuo; 松尾　淳; Tetsuji Asano; 浅野　哲司
Original assignee: JFE Koken Co Ltd
Current assignee: JFE Koken Co Ltd
Priority date: 2002-10-04
Filing date: 2002-10-04
Publication date: 2004-04-22

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the amount of earth and sand to be excavated and to greatly reduce execution time when burying a pipe into the ground by an open-cut method, and further to surely prevent the subsidence of the ground surface after backfill. <P>SOLUTION: After an excavation groove 2 for burying the pipe 1 is excavated by an extremely small width having a margin of a maximum of 10cm to the left and right to a diameter D of the pipe 1 to be buried and then the pipe 1 is arranged in the excavation groove 2, slurry-like fluidized soil 5, where water, earth and sand, and a setting agent are mixed at a position without exceeding the 1/2 of the diameter of the pipe 1, thus immediately throwing the earth and sand 6 to the upper portion of the fluidized soil for rolling. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、例えばガス管や上下水道管等を開削工法により地中に敷設するときの管埋設工法、特に、掘削する土砂量の低減と施工時間の短縮及び埋め戻し後の地表面の沈下の防止に関するものである。
【０００２】
【従来の技術】
【特許文献１】特開平９−６７５７３号工法
例えばガス管等を開削工法で地中に埋設する場合、図４の断面図に示すように、管１を埋設する場所に、埋設する管１の直径Ｄに対して少なくとも左右に３０ｃｍ程度の余裕を持たせた幅Ｗ１の掘削溝２ａを構築する。この掘削溝２ａに管１を配設した後、掘削溝２ａを山砂又は再生土６で埋め戻してランマなどにより締め固めてから路盤７や表層８などの上層部を施工している。この掘削溝２ａを埋め戻すときに、管周辺部などの狭隘な部分にも隙間なく埋戻し材を充填するために、例えば特許文献１等に示されているように、掘削溝２ａ内に配設した管１の周辺部と上部に流動化土を打設し、流動化土が固化してからランマ等で土砂を転圧している。
【０００３】
【発明が解決しようとする課題】
このように掘削溝を埋設する管の直径に対して少なくとも左右に３０ｃｍ程度の余裕を持たせて掘削すると、掘削する土砂の量すなわち残土の処分量が大量になるとともに、埋戻し材料も大量に必要になってしまう。
【０００４】
また、管と掘削溝の壁面との距離が３０ｃｍ程度の余裕がある場合、管の周辺部に打設した流動化土が固化するまでに２〜４時間と時間がかかり、土砂を転圧するまで待機する必要があり、施工時間が長くなってしまう。
【０００５】
この発明はかかる短所を改善し、開削工法により地中に管を埋設するときの掘削する土砂量を低減するとともに施工時間を大幅に短縮し、さらに埋め戻し後の地表面の沈下を確実に防止することができる管埋設工法を提供することを目的とするものである。
【０００６】
【課題を解決するための手段】
この発明の管埋設工法は、開削工法により地表面下に管を埋設する管埋設工法において、管を埋設する掘削溝を、埋設する管の直径に対して左右に最大で１０ｃｍの余裕を持たせた極小幅で掘削し、掘削溝に管を配設し、管の直径の１／２を越えない位置まで水と土砂と固化剤を混合したスリラー状の流動化土を流し込んで埋め戻し、流動化土の上部に直ちに土砂を投入して転圧することを特徴とする。
【０００７】
【発明の実施の形態】
図１はこの発明の管埋設工法を示す断面図である。開削工法で例えばガス管等の管１を地中に埋設する場合、管１を埋設する場所に、埋設する管１の直径Ｄに対して左右に最大で１０ｃｍ程度の余裕を持たせた幅Ｗの掘削溝２を構築する。この掘削溝２に管１を吊り下ろして配設した後、図２の側面断面図に示すように、布堀部３の両端に土のう４を積み上げる。この状態で、地表面に配置したミキサーに水と土砂とたとえば高炉セメント等をの主成分とした固化材を投入し、混練してスラリー状の流動化土を作成し、作成した流動化土５を布堀部３に打設する。この流動化土５を打設するとき、掘削溝２に配設された管１の直径Ｄの１／２を越えない位置まで流動化土５を流し込む。この流動化土５を流し込むとき、布堀部３の両端に土のう４が積み上げてあるから、流動化土５が流出することを防止して、所定の位置まで流動化土５を流し込むことができる。掘削溝２の所定の位置まで流動化土５を流し込んだ後、直ちに山砂又は再生土６を埋め戻してランマ等で転圧して締め固める。この山砂又は再生土６の埋め戻しと転圧作業は、例えば厚さ３０ｃｍ毎に掘削深さに応じて数層行う。この山砂又は再生土６の埋め戻しと転圧作業を行った後、路盤７や表層８などの上層部を施工する。
【０００８】
このように管１の直径Ｄに対して左右に最大で１０ｃｍ程度の余裕を持たせた幅Ｗの掘削溝２の管１の直径Ｄの１／２を越えない位置まで流動化土５を流し込むことにより、流動化土５が固化して強度を発現する前に直ちに山砂又は再生土６を投入して転圧することができる。これは流動化土５の上部の山砂又は再生土６による荷重分散効果と管１と掘削溝２の壁面との隙間が最大で１０ｃｍと狭いことによるアーチ作用により流動化土５の表面への荷重はほとんど作用しないためである。
【０００９】
【実施例】
例えば実施例として口径２００Ａと３００Ａと４００Ａと５００Ａ及び６００Ａの管１を使用し、管１の直径Ｄに対して左右に１０ｃｍ程度の余裕を持たせた幅Ｗの掘削溝２を掘削して管１を配設し、掘削溝２の管１の直径Ｄの１／２を越えない位置まで流動化土５を流し込んで山砂又は再生土６を直ちに投入して転圧した。このとき使用した流動化土５の品質は、材令２８日で一軸圧縮強度ｑｕ≦０．３〜０．５ＭＰａ、フロー値は２５０ｍｍ〜３５０ｍｍ、ブリーディング率は３％以内である。また、比較例として、従来工法により、図３に示すように、管１の直径Ｄに対して左右に３０ｃｍ程度の余裕を持たせた幅Ｗ１の掘削溝２ａを掘削して管１を配設して、管１の周辺部と上部に流動化土５を打設し、流動化土５が固化してからランマ等で土砂を転圧した。
【００１０】
この実施例の場合、従来工法に比較して掘削溝２の幅が小さくなることから、掘削土砂の量は従来工法と比較して、表１の掘削土砂量の削減率に示すように、大幅に削減することができ、例えば４００Ａの口径の管１の場合で４３％削減することができた。したがって埋戻し材料も従来工法と比べて大幅に削減することができる。
【００１１】
【表１】

【００１２】
また、実施例の場合は、流動化土５を流し込んで直ちに山砂又は再生土６を投入して転圧することができ、流動化土５の固化を待つ必要がないから、施工時間を大幅に短縮することができ、長距離の施工を短時間で行うことができる。
【００１３】
さらに、実施例と従来工法で３００Ａの管１を埋設後、その地表面にトラックを走行させて、図３の断面図に示すように、管横部１０と管上部１１及び地表面１２の沈下量を計測した結果を表２に示す。
【００１４】
【表２】

【００１５】
表２に示すように、実施例の場合、管１の沈下量と地表面の沈下量はいずれも従来工法より小さいことが確認できた。
【００１６】
【発明の効果】
この発明は以上説明したように、管を埋設する掘削溝を、埋設する管の直径に対して左右に最大で１０ｃｍの余裕を持たせた極小幅で掘削するようにしたから、掘削土砂の量を大幅に削減することができるとともに埋戻し材料も大幅に削減することができ、管を埋設するときの掘削土の処理費用や埋戻し材料の費用を低減することができる。
【００１７】
また、掘削溝を埋設する管の直径に対して左右に最大で１０ｃｍの余裕を持たせた極小幅で掘削するとともに、掘削溝に配設した管の直径の１／２を越えない位置までスリラー状の流動化土を流し込んで埋め戻すことにより、流動化土を流し込んでから直ちに土砂を投入して転圧すことができ、施工時間を大幅に短縮することができる。
【００１８】
さらに、管下側に充填性が優れた流動化土を打設することにより、管周囲の転圧不足に起因する地表面の沈下が生じることを防ぐことができる。
【００１９】
また、流動化土を流し込んでいるとき、管には振動が発生しないから、流動化土を流し込んでいるときに埋設する管を溶接して接合することができ、管の接合と埋設を効率良く行うことができる。
【図面の簡単な説明】
【図１】この発明の管埋設工法を示す断面図である。
【図２】流動化土を打設した状態を示す側面断面図である。
【図３】管埋設後の沈下量の測定位置を示す断面図である。
【図４】従来工法を示す断面図である。
【符号の説明】
１；管、２；掘削溝、３；布堀部、４；土のう、５；流動化土、
６；山砂又は再生土、７；路盤、８；表層。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pipe burying method for laying gas pipes, water and sewage pipes and the like in the ground by an open-cutting method, and in particular, to reduce the amount of excavated earth and sand, shorten the construction time, and settle the ground surface after backfilling. It is about prevention.
[0002]
[Prior art]
[Patent Document 1] Japanese Patent Application Laid-Open No. 9-67573. For example, when a gas pipe or the like is buried in the ground by an open-cutting method, as shown in a sectional view of FIG. An excavation groove 2a having a width W1 having at least a left and right margin of about 30 cm with respect to the diameter D is constructed. After arranging the pipe 1 in the excavation groove 2a, the excavation groove 2a is backfilled with mountain sand or reclaimed soil 6 and compacted by a rammer or the like, and then the upper layers such as the roadbed 7 and the surface layer 8 are constructed. When backfilling the excavation groove 2a, in order to fill a narrow portion such as a pipe peripheral portion with the backfill material without any gap, for example, as shown in Patent Document 1 or the like, the excavation groove 2a is disposed in the excavation groove 2a. Fluidized soil is poured around and above the pipe 1 provided, and after the fluidized soil is solidified, the soil is compacted with a rammer or the like.
[0003]
[Problems to be solved by the invention]
When digging with a margin of at least about 30 cm on the left and right with respect to the diameter of the pipe in which the digging trench is buried, the amount of excavated earth and sand, that is, the disposal amount of residual soil, becomes large, and the backfill material also becomes large. You will need it.
[0004]
In addition, when the distance between the pipe and the wall of the excavation groove has a margin of about 30 cm, it takes 2 to 4 hours to solidify the fluidized soil cast around the pipe, and until the soil is compacted. It is necessary to wait, and the construction time becomes longer.
[0005]
This invention improves such disadvantages, reduces the amount of excavated earth and sand when burying pipes in the ground by open-cutting, significantly shortens the construction time, and reliably prevents the settlement of the ground surface after backfilling It is an object of the present invention to provide a pipe burying method that can perform the method.
[0006]
[Means for Solving the Problems]
The pipe burial method according to the present invention is a pipe burial method in which a pipe is buried below the ground surface by an open-cutting method, wherein the excavation groove for burying the pipe has a maximum of 10 cm left and right with respect to the diameter of the pipe to be buried. Excavation with a very small width, laying a pipe in the digging trench, pouring in a chiller-like fluidized soil mixed with water, earth and sand, and a solidifying agent to a position not exceeding 1/2 of the diameter of the pipe, backfilling, and flowing It is characterized by immediately putting earth and sand into the upper part of the fossilized soil and compacting it.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a sectional view showing a pipe burying method according to the present invention. When the pipe 1 such as a gas pipe is buried in the ground by the open-cutting method, the width W of the place where the pipe 1 is buried has a maximum width of about 10 cm left and right with respect to the diameter D of the buried pipe 1. Of the excavation groove 2 of. After hanging the pipe 1 in the excavation groove 2 and arranging it, sandbags 4 are piled up on both ends of the cloth moat part 3 as shown in the side sectional view of FIG. In this state, water, earth and sand, and a solidifying material mainly containing blast furnace cement, for example, are put into a mixer arranged on the ground surface, and the mixture is kneaded to form a slurry-like fluidized soil. Into the cloth moat part 3. When the fluidized soil 5 is cast, the fluidized soil 5 is poured to a position not exceeding 1/2 of the diameter D of the pipe 1 provided in the excavation groove 2. When the fluidized soil 5 is poured, since the sandbags 4 are piled up at both ends of the cloth moat portion 3, the fluidized soil 5 can be prevented from flowing out and the fluidized soil 5 can be poured to a predetermined position. Immediately after pouring the fluidized soil 5 to a predetermined position in the excavation groove 2, the mountain sand or the reclaimed soil 6 is backfilled and compacted by rolling with a rammer or the like. The backfilling of the mountain sand or the reclaimed soil 6 and the compaction work are performed, for example, in several layers every 30 cm in accordance with the excavation depth. After backfilling and compacting the mountain sand or the reclaimed soil 6, the upper layers such as the roadbed 7 and the surface layer 8 are constructed.
[0008]
As described above, the fluidized soil 5 is poured to a position not exceeding 1/2 of the diameter D of the pipe 1 of the excavation groove 2 having a width W having a maximum of about 10 cm left and right with respect to the diameter D of the pipe 1. Thus, the mountain sand or the reclaimed soil 6 can be immediately charged and compacted before the fluidized soil 5 solidifies and develops strength. This is due to the effect of the load distribution by the mountain sand or the reclaimed soil 6 on the upper part of the fluidized soil 5 and the arching effect due to the narrow gap between the pipe 1 and the wall surface of the excavation groove 2 of 10 cm at the maximum. This is because the load hardly acts.
[0009]
【Example】
For example, a pipe 1 having a diameter of 200A, 300A, 400A, 500A, and 600A is used as an example, and a pipe 2 is formed by digging a pit 2 having a width W of about 10 cm left and right with respect to the diameter D of the pipe 1. 1 and the fluidized soil 5 was poured to a position not exceeding １／ of the diameter D of the pipe 1 in the excavation groove 2, and mountain sand or reclaimed soil 6 was immediately charged and compacted. The quality of the fluidized soil 5 used at this time is as follows: 28 days old, the unconfined compressive strength qu ≦ 0.3-0.5 MPa, the flow value is 250-350 mm, and the bleeding rate is within 3%. As a comparative example, as shown in FIG. 3, the pipe 1 is laid by excavating a digging groove 2a having a width W1 having a margin of about 30 cm left and right with respect to the diameter D of the pipe 1 by a conventional method. Then, the fluidized soil 5 was cast around and above the pipe 1, and after the fluidized soil 5 was solidified, the soil was compacted with a rammer or the like.
[0010]
In the case of this embodiment, since the width of the excavation groove 2 is smaller than that of the conventional method, the amount of excavated sediment is significantly lower than that of the conventional method, as shown in the reduction rate of the amount of excavated sediment in Table 1. For example, in the case of the pipe 1 having a diameter of 400 A, the reduction was 43%. Therefore, the backfill material can be significantly reduced as compared with the conventional method.
[0011]
[Table 1]

[0012]
In addition, in the case of the embodiment, the sand 5 or the reclaimed soil 6 can be poured immediately after the fluidized soil 5 is poured and the soil can be compacted, and it is not necessary to wait for the solidification of the fluidized soil 5. It can be shortened, and long-distance construction can be performed in a short time.
[0013]
Further, after burying the 300A pipe 1 in the embodiment and the conventional method, a truck is run on the ground surface, and as shown in the sectional view of FIG. Table 2 shows the results of the measurement.
[0014]
[Table 2]

[0015]
As shown in Table 2, in the case of the example, it was confirmed that the settlement amount of the pipe 1 and the settlement amount of the ground surface were both smaller than the conventional method.
[0016]
【The invention's effect】
As described above, according to the present invention, the excavation trench for burying a pipe is excavated with a very small width having a maximum of 10 cm left and right with respect to the diameter of the buried pipe. Can be greatly reduced, and the backfill material can also be significantly reduced, so that the cost of treating excavated soil and the cost of the backfill material when burying the pipe can be reduced.
[0017]
In addition, excavation is performed with a minimum width of 10 cm at the left and right with respect to the diameter of the pipe in which the digging groove is buried. By pouring and refilling the fluidized soil in a shape, the sand can be immediately injected and compacted immediately after the fluidized soil is poured, and the construction time can be greatly reduced.
[0018]
Furthermore, by pouring fluidized soil having excellent filling properties below the pipe, it is possible to prevent the ground surface from sinking due to insufficient rolling pressure around the pipe.
[0019]
Also, when fluidized soil is poured, the pipes do not vibrate, so the pipes to be buried can be welded and joined when the fluidized soil is poured, and the joining and embedding of pipes can be performed efficiently. It can be carried out.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a pipe burying method according to the present invention.
FIG. 2 is a side sectional view showing a state where fluidized soil is cast.
FIG. 3 is a cross-sectional view showing a measurement position of a settlement amount after the pipe is buried.
FIG. 4 is a cross-sectional view showing a conventional method.
[Explanation of symbols]
1; pipe, 2; excavation groove, 3; cloth pit, 4; sandbag, 5; fluidized soil,
6; mountain sand or reclaimed soil; 7; roadbed; 8;

Claims

In the pipe burial method where the pipe is buried below the ground surface by the open-cutting method, the digging groove for burying the pipe is excavated with a minimum width of 10 cm left and right with respect to the diameter of the pipe to be buried. A pipe is placed in the groove, and a chiller-like fluidized soil mixed with water, earth and sand, and a solidifying agent is poured back to a position that does not exceed 1/2 of the diameter of the pipe, and backfilled. A pipe burial method characterized by charging and rolling.