JPS6351597A - Method of impact type propulsion construction - Google Patents
Method of impact type propulsion constructionInfo
- Publication number
- JPS6351597A JPS6351597A JP19501786A JP19501786A JPS6351597A JP S6351597 A JPS6351597 A JP S6351597A JP 19501786 A JP19501786 A JP 19501786A JP 19501786 A JP19501786 A JP 19501786A JP S6351597 A JPS6351597 A JP S6351597A
- Authority
- JP
- Japan
- Prior art keywords
- steel pipe
- impact
- impact type
- type propulsion
- head
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 14
- 238000010276 construction Methods 0.000 title description 2
- 229910000831 Steel Inorganic materials 0.000 claims description 54
- 239000010959 steel Substances 0.000 claims description 54
- 238000007796 conventional method Methods 0.000 description 11
- 239000002689 soil Substances 0.000 description 6
- 230000003584 silencer Effects 0.000 description 5
- 238000003466 welding Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 210000002445 nipple Anatomy 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は地表面を掘り起すことなく各種配管を埋設する
衝撃式推進工法に関するもので、推進効率が優れ、騒音
が少く、さらに装置を軽量化でき、経済的であることを
特徴とするものである。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an impact type propulsion method for burying various types of piping without digging up the ground surface, which has excellent propulsion efficiency, low noise, and lightweight equipment. It is characterized by being flexible and economical.
従来、各種のケーブル敷設のための配管、給水管、排水
管等を埋設する方法として、地表面を掘り起す方法の他
、ハンマーのごとく作用するピストンを内蔵した衝撃式
推進機で鋼管を地中に推進して埋設し、後に鋼管内部の
土砂を排出する衝撃式推進工法が提供されている。Traditionally, various methods for burying pipes, water supply pipes, drainage pipes, etc. for laying various cables include digging up the ground surface, as well as burying steel pipes underground using an impact propulsion machine with a built-in piston that acts like a hammer. An impact propulsion method is available, in which the steel pipe is propelled into the ground, buried, and the earth and sand inside the pipe are later discharged.
この衝撃式推進工法は地表面を掘り起すことがないため
、その掘り起し作業が不要であるとともに支圧壁も不要
であり、作業完了後の埋めもどし作業も不要で経済的で
あり、さらに地盤゛沈下、陥没等のおそれもない利点を
有する。Since this impact propulsion method does not involve digging up the ground surface, it does not require digging work, does not require bearing walls, and does not require backfilling after work is completed, making it economical. It has the advantage that there is no risk of ground subsidence or collapse.
従来、上記衝撃式推進工法として、矛４図、矛５図示の
ごとき方法が提供されている。Conventionally, methods as shown in Figures 4 and 5 have been provided as the above-mentioned impact type propulsion method.
まず、矛４図の方法について述べると、推進させる鋼管
−の後端外周にバンドＱカを取り付は後端内部にラムコ
ーン勾を設け、該ラムコーン（２）に衝撃式推進機りの
ヘッド（ハ）を適合させ、衝撃式推進機りを駆動させ、
同時に前進させるものである。First, to describe the method shown in Figure 4, a band Q is attached to the outer periphery of the rear end of the steel pipe to be propelled, a ram cone slope is provided inside the rear end, and the head of the impact type propulsion machine (2) is attached to the ram cone (2). c) and drive the impact propulsion machine,
At the same time, it moves us forward.
なお、上記衝撃式推進機器の駆動とは後に述べるが、圧
縮空気の力によって内蔵ピストンを往復動させ、該ピス
トンをヘッド？４の後面に衝突させ、ハンマーのごとき
衝撃をヘッド（ハ）を介して鋼管０１π伝え、該鋼管−
を土中に推進させることを言うものである。The driving of the above-mentioned impact type propulsion device will be described later, but the built-in piston is reciprocated by the force of compressed air, and the piston is moved to the head. 4, and a hammer-like impact is transmitted through the head (c) of the steel pipe 01π, and the steel pipe -
It refers to the act of propelling something into the soil.
同図において、（２０α）は先に推進させた鋼管、（ハ
）は溶接部、（ハ）はコンプレッサー、勾は作業用クレ
ーン付トラック、（至）は立坑である。In the figure, (20α) is the previously propelled steel pipe, (c) is the welded part, (c) is the compressor, slope is the truck with a working crane, and (to) is the shaft.
つぎに、牙５図の方法について述べる。Next, the method of Fang 5 will be described.
なお、矛５図の説明において矛４図と同じ部分は同じ符
号を附している。In the explanation of Figure 5, the same parts as Figure 4 are given the same reference numerals.
この方法は立坑（至）が小さくてすむ効果が得られるも
ので、鋼管（イ）の内部に特殊構成のケーシングコーン
四を介して衝撃式推進機りを設け、ケーシングコーン翰
により鋼管（１）の後端に衝撃を加え、鋼管−を土中に
推進させるものである。This method has the effect of making the vertical shaft smaller, and an impact propulsion mechanism is installed inside the steel pipe (A) via a specially configured casing cone (4), and the steel pipe (1) is moved by the casing cone. This applies an impact to the rear end of the steel pipe, propelling it into the soil.
上記牙４図に示された従来の方法は立坑（至）が必然的
九人きくなり、その掘り起し作業に時間と労力を要し、
不経済である欠点がある。The conventional method shown in Fig. 4 above requires nine people to dig the shaft, and it takes time and effort to dig it out.
It has the disadvantage of being uneconomical.
すなわち、矛４図における立坑（ハ）の巾（Ｗ）は少く
とも鋼管（７）の長さと衝撃式推進機器の長さをプラス
した長さ以上でなければならないものである。That is, the width (W) of the shaft (C) in Figure 4 must be at least equal to or greater than the length of the steel pipe (7) plus the length of the impact type propulsion device.
さらに、この方法では衝撃式推進機（イ）の駆動中にラ
ムコーン器とヘッド０４間ｄ＝ら大きな衝撃音が生じ、
層音が犬きく、作業員の党康上好ましくなく、さらにま
た、場合によってはラムコーン器からヘッド（財）が抜
けなくなるとともに鋼管−の後端が変形して溶接による
連結が困難となる場合があり、さらにまた推進させる鋼
管麹と衝撃式推進機器が別々にしかも直線状に設けられ
、鋼管□□□の後端に衝撃を加える方式であるため鋼管
−の推進方向性が悪く、方向性の制御と矯正等に手数を
要する欠点がある。Furthermore, in this method, a large impact sound is generated between the ram cone device and the head 04 while driving the impact type propulsion device (a),
The sound is loud, which is not good for the health of the workers.Furthermore, in some cases, the head cannot be removed from the ram cone, and the rear end of the steel pipe may become deformed, making it difficult to connect by welding. In addition, the steel pipe koji and the impact type propulsion device are installed separately and in a straight line, and the method applies an impact to the rear end of the steel pipe, so the directionality of the steel pipe is poor and the directionality is poor. It has the disadvantage that control and correction require a lot of effort.
つぎに、牙５図に示された従来の方法は鋼管−の内部に
特殊構成のケーシングコーン翰を介して衝撃式推進機り
を設けているため、立坑（ホ）の巾（Ｓ）を鋼管−の長
さ以上とすればよく、上記矛４図に示された従来の方法
よりも立坑（ハ）を小さくでき、経済的である効果が得
られるが、衝撃式推進機器の衝撃を特殊構成のケーシン
ウ喝の先端に加え、その後端を鋼管−の後端に係止させ
て伝達するものであるため、鋼管（ホ）に加えられる衝
撃力が半減させられ、推進効率が悪い欠点があり、さら
に特殊構成のケーシングコーン四の使用により構成が複
雑となり、重量も増加して作業性が悪く、さらに上記矛
４図に示された従来の方法と同様に唐音が大きく、さら
に鋼管勾の後端連結部が変形させられる場合があった。Next, in the conventional method shown in Fig. 5, an impact propulsion mechanism is installed inside the steel pipe through a specially constructed casing cone, so the width (S) of the shaft (E) is - length or more, the vertical shaft (c) can be made smaller than the conventional method shown in Figure 4 above, and an economical effect can be obtained. In addition to the tip of the casing, the rear end is locked to the rear end of the steel pipe for transmission, so the impact force applied to the steel pipe (e) is halved, which has the disadvantage of poor propulsion efficiency. Furthermore, the use of the specially constructed casing cone 4 complicates the construction, increases weight, and reduces workability.Furthermore, similar to the conventional method shown in Fig. In some cases, the end connections were deformed.
本発明は上記欠点を除去してなるもので、立坑が小さく
てすむため経済的であり、さらに騒音を約２分の１に減
すことができ、衝撃力を有効に働かせるため、推進効率
が優れ、鋼管の方向性もよく連結部の変形も生ぜず溶接
作業も安全且つ容易に行うことができ、鋼管の傷、変形
等を無くすることができ、しかも装置重量の軽減が図ら
れ、狭い場所での作業効率を向上させることができるも
のである。The present invention eliminates the above-mentioned drawbacks, and is economical because it requires a small shaft. Furthermore, the noise can be reduced to about half, and the impact force is effectively used, so the propulsion efficiency is improved. Excellent, the direction of the steel pipe is good, there is no deformation of the connection part, welding work can be performed safely and easily, there is no damage or deformation of the steel pipe, and the weight of the equipment is reduced, and it can be used in narrow spaces. This is something that can improve work efficiency at a location.
本発明は上記間頂点を解決するため、推進させる鋼管先
端内部に衝撃式推進機のヘッドを係合させ、衝撃式推進
機を駆動させて鋼管を推進させることを特徴とするもの
である。In order to solve the above problem, the present invention is characterized in that the head of an impact type propulsion device is engaged inside the tip of the steel pipe to be propelled, and the impact type propulsion device is driven to propel the steel pipe.
本発明では従来と異り、推進させる鋼管先端内部に衝撃
式推進機のヘッドが係合させられろ。In the present invention, unlike the conventional method, the head of the impact type propulsion device is engaged inside the tip of the steel pipe to be propelled.
それらは具体的には必要π応じて鋼管先端内部に係止部
を構成し、あるいは鋼管先端内部の局面と衝撃式推進機
のヘッド間にくさびを介在させる等して行われる。Specifically, these are carried out by constructing a locking part inside the tip of the steel pipe according to necessity, or by interposing a wedge between the curve inside the tip of the steel pipe and the head of the impact type propulsion device.
さらては上記係止部とくさびが併用される。Furthermore, the above-mentioned locking portion and wedge are used together.
したが′つて、本発明では推進させる鋼管内部に衝撃式
推進機が設けられるため、立坑は上記矛５図に示した従
来の方法と同様に小さくてすみ経済的である。However, in the present invention, since an impact type propulsion device is provided inside the steel pipe for propulsion, the vertical shaft can be made small and economical, similar to the conventional method shown in Figure 5 above.
そして、その状態で衝撃式推進機が駆動させられる。Then, in this state, the impact type propulsion device is driven.
その結果、本発明では推進させる鋼管の先端に衝撃力が
加えられて土中’ｔＣ推進させられる。As a result, in the present invention, an impact force is applied to the tip of the steel pipe to be propelled, and the steel pipe is propelled into the soil.
したがって、急告は推進させる鋼管内で発生し、従来の
ごとく立坑内で直接発生せず、またその大半が土中に消
え゛るため極めて小さいものであリ、さらに従来の方法
と異り、構造上鋼管の後端部にサイレンサーをつげるこ
とが可能であり、該サイレンサーをつけることにより窯
音を大巾に減少させることができるものである。Therefore, the emergency is generated within the propelling steel pipe, not directly within the shaft as in the conventional method, and most of it disappears into the soil, so it is extremely small. Furthermore, unlike the conventional method, the It is possible to attach a silencer to the rear end of the upper steel pipe, and by attaching the silencer, the kiln noise can be greatly reduced.
さらにまた、推進させる鋼管の先端に直接衝撃力が加え
られるため、推進効率も優れ、鋼”管の方向性もよく、
さらに従来のごとく、鋼管後端部の変形も生じないため
、溶接による連結作業も完全且つ容易である効果が得ら
れるものである。Furthermore, since the impact force is applied directly to the tip of the steel pipe being propelled, the propulsion efficiency is excellent, and the directionality of the steel pipe is also good.
Furthermore, unlike the conventional method, there is no deformation of the rear end of the steel pipe, so the connection work by welding is complete and easy.
また、上記衝撃式推進機のヘッドの係合方法として複数
に分割したくさびを使用すると、各種サイズの鋼管及び
衝撃式推進機とのヘッドの係合に利用できるものである
。Further, if a wedge divided into a plurality of pieces is used as a method for engaging the head of the above-mentioned impact type propulsion device, it can be used to engage the head with steel pipes of various sizes and impact type propulsion devices.
以下に本発明を実施する装置の一実施例を牙１図乃至牙
３図について説明する。An embodiment of the apparatus for carrying out the present invention will be described below with reference to Figs. 1 to 3.
まず、衝撃式推進機（α）について述べると、牙３図示
のごとく、本体ケーシング（１）の先端にヘッド（２）
が構成され、本体ケーシング（１）の内部に設けられた
ピストン（３）がエアーホース（４）、エアーコントロ
ールバルブ（５）を介して送られた圧縮空気の力によっ
てヘッド（２）部を叩き、ヘッド（２）により鋼管（９
）に衝撃を加えて推進させるものである。First, regarding the impact type propulsion device (α), as shown in Fig. 3, there is a head (2) at the tip of the main casing (1).
A piston (3) provided inside the main casing (1) hits the head (2) by the force of compressed air sent through the air hose (4) and air control valve (5). , steel pipe (9) by the head (2)
) is propelled by applying an impact to it.
す々わち、その詳細を示していないがエアーコントロー
ルバルブ（５）によりピストン（３）が往復動してヘッ
ド（２）部を叩くように構成されている。Although the details are not shown, the piston (3) is configured to reciprocate and strike the head (2) by an air control valve (5).
さらに本発明においては衝撃式推進機全体を後退させる
装置を設けることが望ましい。Furthermore, in the present invention, it is desirable to provide a device for retracting the entire impact type propulsion machine.
それらは例えば具体的にはエアーコントロールバルブ（
５）を所定角度回転させて圧縮空気を供給すると、ピス
トン（３）の先端が先端方向にあるヘッド（２）を叩か
ずにピストン（３）の後端が本体ケーシングの後端方向
に設けた壁（６）を叩くように構成すればよいものであ
る。They are, for example, specifically air control valves (
5) is rotated by a predetermined angle and compressed air is supplied, the tip of the piston (3) does not hit the head (2) located in the tip direction, and the rear end of the piston (3) is placed in the rear end direction of the main casing. What is necessary is to configure it so that it hits the wall (6).
図中（７）は後部ニップル、（８）はホースバンドであ
る。In the figure, (7) is the rear nipple, and (8) is the hose band.
本発明では上記のごとき衝撃式推進機（α）のヘッド（
２）が推進させる鋼管（９）の先端内部に保合させられ
る。In the present invention, the head (
2) is held inside the tip of the propelling steel pipe (9).
その具体例が矛１図、矛２図に示されている。Specific examples are shown in Figures 1 and 2.
図面実施例の場合、推進させる鋼管（９）の先端内部に
帯鋼α０が溶接され、その後方内部に全体が円筒状とな
り、その後端面から円錐状孔（１１α）が構成され、先
端外周が上記帯鋼０Ｑに係止するくさび０］）が設けら
れ、該〈さびα■の円錐状孔（１１α）に衝撃式推進機
（α）のヘッド（２）が係合するよう構成されている。In the case of the embodiment shown in the drawings, a steel band α0 is welded inside the tip of the steel pipe (9) to be propelled, and the entire rear inside thereof is cylindrical, a conical hole (11α) is formed from the rear end surface, and the outer periphery of the tip is as described above. A wedge 0]) that engages the steel strip 0Q is provided, and the head (2) of the impact propulsion device (α) is configured to engage with the conical hole (11α) of the wedge α.
々お、上記ぐさびαυは複数に分割され、各種サイズの
鋼管及び衝撃式推進機とのヘッドの係合に利用できるよ
う構成されている。Furthermore, the wedge αυ is divided into a plurality of parts and is configured so that it can be used for engaging the head with steel pipes of various sizes and impact type propulsion machines.
図中αａは衝撃式推進機（α）の後端のセンターリング
装置、０３はサイレンサー、α→は先に推進させた鋼管
、α→は溶接部、００は立坑である。In the figure, αa is the centering device at the rear end of the impact type propulsion machine (α), 03 is the silencer, α→ is the steel pipe that was propelled earlier, α→ is the welded part, and 00 is the shaft.
上記構成の本発明は衝撃式推進機（α）を駆動させると
内部ピストン（３）が往復動してヘッド（２）を叩き、
それに伴いヘッド（２） Ｋ加えられた衝撃がくさびα
◇を介して鋼管α０に加えられ、該鋼管αＱが土中に推
進させられるものである。In the present invention having the above configuration, when the impact type propulsion device (α) is driven, the internal piston (3) reciprocates and hits the head (2),
As a result, the impact applied to the head (2) K creates a wedge α.
It is added to the steel pipe α0 via ◇, and the steel pipe αQ is propelled into the soil.
そして、鋼管αＱの推進が完了したらエアーコントロー
ルバルブ（５）を操作して衝撃式推進機（α）の後退操
作を行えばよいものである。その後、１＠次、鋼管が連
結されて上記と同様の方法で推進させられるものである
。Then, when the propulsion of the steel pipe αQ is completed, the air control valve (5) is operated to perform a retreat operation of the impact propulsion device (α). Thereafter, the steel pipes are connected and propelled in the same manner as described above.
上記のごとく、本発明では衝撃式推進機（α）の衝撃力
が従来と異り、推進させる鋼管αＱの先端部に加えられ
る。As described above, in the present invention, the impact force of the impact type propulsion device (α) is applied to the tip of the steel pipe αQ to be propelled, unlike the conventional method.
その結果、騒音は推進させる鋼管内で発生し、従来のご
とく立坑内で直接発生せず、またその大半が土中に消え
るため柩めで小さいものであり、さらに従来の方法と異
り、構造上鋼管の後端部にサイレンサーをつけることが
可能であり、該サイレンサーをつけることにより騒音を
大巾に減少させることができるものである。As a result, the noise is generated within the propelling steel pipe and not directly inside the shaft as in conventional methods, and most of it disappears into the soil, making it small and rectangular. It is possible to attach a silencer to the rear end of the steel pipe, and by attaching the silencer, noise can be greatly reduced.
さらにまた、推進させる鋼管の先端に直接衝撃力が加え
られるため、推進効率も優れ、鋼管の方向性もよく、さ
らに従来のごとく、鋼管後端部の変形も生じないため、
溶接による連結作業も容易である効果が得られるもので
ある。Furthermore, since the impact force is applied directly to the tip of the steel pipe to be propelled, the propulsion efficiency is excellent and the directionality of the steel pipe is good, and there is no deformation of the rear end of the steel pipe as in the conventional case.
This has the advantage that the connection work by welding is easy.
図面は本発明を実施する装置の一実施例を示し、矛１図
は実施状態を示す一部断面側面図。
矛２図は矛１図Ａ−Ａ線断面図、矛３図は衝撃式推進機
の要部断面図、矛４図、矛５図は従来の実施状態を示す
一部断面側面図である。
（１）・・・本体ケーシング、（２）・・・ヘッド、（
３）・・・ピストン、（４）・・・エアーホース、（５
）・・・コントロールバルブ、 （９）・・・鋼管、α
１・・・帯鋼、◇ｐ・・・くさび、（１１α）・・・円
錐状孔、（α）・・・衝撃式推進機・The drawings show an embodiment of an apparatus for implementing the present invention, and FIG. 1 is a partially sectional side view showing the state of implementation. Figure 2 is a sectional view taken along the line A--A in Figure 1, Figure 3 is a sectional view of a main part of the impact type propulsion device, and Figures 4 and 5 are partially sectional side views showing conventional implementation. (1)...Body casing, (2)...Head, (
3)... Piston, (4)... Air hose, (5
)...Control valve, (9)...Steel pipe, α
1...Strip steel, ◇p...Wedge, (11α)...Conical hole, (α)...Impact type propulsion machine・
Claims (1)
させ、衝撃式推進機を駆動させて鋼管を推進させること
を特徴とする衝撃式推進工法。An impact type propulsion method characterized by engaging the head of an impact type propulsion device inside the tip of the steel pipe to be propelled, and driving the impact type propulsion device to propel the steel pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19501786A JPS6351597A (en) | 1986-08-20 | 1986-08-20 | Method of impact type propulsion construction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19501786A JPS6351597A (en) | 1986-08-20 | 1986-08-20 | Method of impact type propulsion construction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6351597A true JPS6351597A (en) | 1988-03-04 |
| JPH0475993B2 JPH0475993B2 (en) | 1992-12-02 |
Family
ID=16334145
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19501786A Granted JPS6351597A (en) | 1986-08-20 | 1986-08-20 | Method of impact type propulsion construction |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6351597A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6378999A (en) * | 1986-09-22 | 1988-04-09 | 松坂貿易株式会社 | Impact propulsion construction method and device for steel pipe |
-
1986
- 1986-08-20 JP JP19501786A patent/JPS6351597A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6378999A (en) * | 1986-09-22 | 1988-04-09 | 松坂貿易株式会社 | Impact propulsion construction method and device for steel pipe |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0475993B2 (en) | 1992-12-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4640649A (en) | Method and apparatus for forming an underground solidification structure | |
| JPS6351597A (en) | Method of impact type propulsion construction | |
| JP2002275892A (en) | Method and device for placing steel pipe pile | |
| JPH05140963A (en) | Method and device for ground excavation with pressure air injection and vacuum suction | |
| JP2003155747A (en) | Work machine for pulling out pile | |
| JPS6367396A (en) | Impact type excavator | |
| JP2820247B2 (en) | Pile pull-out method and device | |
| JP2003027469A (en) | Steel pipe pile, foundation pile producing method using the same and device of the method | |
| JP4056604B2 (en) | Ground cutting device | |
| JP6715164B2 (en) | Pipe roof construction method | |
| KR200419260Y1 (en) | A beat for sewer pipe propeling unit | |
| JP2001279666A (en) | Steel pipe erection and steel pipe erection/immersion method | |
| JP3174023B2 (en) | Shaft excavation casing and shaft excavation method | |
| JP2770904B2 (en) | Tunnel prelining method | |
| JP3117811B2 (en) | Two-way switching valve | |
| JP3713777B2 (en) | Burying pipe laying method | |
| JP2799904B2 (en) | How to build a tunnel | |
| JP2001262569A (en) | Pile pulling-out method and pile pulling-out work machine | |
| JPH0696844B2 (en) | Screen pipe placing method and its placing device | |
| JPS6033148Y2 (en) | Pile driving device | |
| JPH0533589A (en) | Method of excavating tunnel, etc., and boring machine thereof | |
| JP3076206B2 (en) | Excavation method of large diameter tunnel and excavation equipment used for the excavation | |
| JP2964406B1 (en) | Driving protection device for protective fence post | |
| JPS6280384A (en) | Method of replacement construction of residual pipe | |
| JP2003035092A (en) | Excavator for square hole and construction method for excavating square hole |