JP4185815B2

JP4185815B2 - Monitor device used for ground improvement method

Info

Publication number: JP4185815B2
Application number: JP2003152312A
Authority: JP
Inventors: 裕治金子
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-05-29
Filing date: 2003-05-29
Publication date: 2008-11-26
Anticipated expiration: 2023-05-29
Also published as: JP2004353298A

Description

【０００１】
【発明が属する技術分野】
本発明は、超高圧噴流体により地盤を切削する工程を含む地盤改良工法に使用するモニター装置に関する。
【０００２】
【従来の技術】
超高圧噴流体により地盤を切削する工程を含む地盤改良工法としては、超高圧噴射工法が知られている。この超高圧噴射工法にはＣＣＰ工法等の単管式超高圧噴射工法、ジェットグラウト工法（ＪＳＧ工法）等の二重管式超高圧噴射工法、コラムジェットグラウト工法（ＣＪＧ工法）やロジンジェットパイル工法（ＲＪＰ工法）等の三重管式超高圧噴射工法等がある。
【０００３】
単管式超高圧噴射工法は、標準施工の場合、地盤中に差し込まれた噴射管（単管）の先端部に設けられた噴射ノズルからセメント系の超高圧硬化材液（セメントミルク）を地盤中に噴射させ、噴射管を回転又は反転させながら引き上げることにより、噴射ノズルから噴射される超高圧硬化材液が構成する超高圧噴流体で地盤を切削すると共に攪拌、混練して円柱状の固結体（地中パイル）を造成する。また水噴射施工の場合には、地盤中に差し込まれた噴射管の先端部に設けられた噴射ノズルから超高圧水を地盤中に噴射させ、噴射管を回転又は反転させながら引き上げることにより、噴射ノズルから噴射される超高圧水が構成する超高圧噴流体で地盤を切削した後、再度噴射管を地盤中に挿入し、前記噴射ノズルからセメント系の超高圧硬化材液（セメントミルク）を噴射させ、噴射管を回転又は反転させながら引き上げることにより、噴射ノズルから噴射される超高圧硬化材液が構成する超高圧噴流体で攪拌、混練して円柱状の固結体（地中パイル）を造成する。
【０００４】
二重管式超高圧噴射工法は、地盤中に差し込まれた噴射管（二重管）の先端部に設けられた噴射ノズルからセメント系の超高圧硬化材液（セメントミルク）を地盤中に噴射させると同時に超高圧硬化材液の噴射ノズルの周囲に設けられた空気ノズルから圧縮空気を噴射させ、噴射管を回転又は反転させながら引き上げることにより、噴射ノズルから噴射される超高圧硬化材液（周囲に空気を沿わせた超高圧硬化材液）が構成する超高圧噴流体で地盤を切削し、スライムをリフト作用により地表に排出させると同時に円柱状の固結体を造成する。
【０００５】
三重管式超高圧噴射工法のうちコラムジェットグラウト工法は、地盤中に差し込まれた噴射管（三重管）の先端部に設けられる噴射ノズルから超高圧水を地盤中に噴射させると同時に超高圧水の周囲に設けられた空気ノズルから圧縮空気を噴射させ、噴射管を回転又は反転させながら引き上げることにより、噴射ノズルから噴射される超高圧水（周囲に空気を沿わせた超高圧水）が構成する超高圧噴流体で地盤を切削し、スライムをリフト作用により地表に排出させると共に超高圧水の噴射ノズルとは別の噴射ノズルからセメント系の高圧硬化材液（セメントミルク）を同時充填させ、円柱状の固結体を造成する。ロジンジェットパイル工法は、地盤中に差し込まれた噴射管（三重管）の先端部に上下二段に取り付く噴射ノズルのうち、上側の噴射ノズルから超高圧水を地盤中に空気包合噴射させ、下側の噴射ノズルからセメント系の高圧硬化材液（セメントミルク）を地盤中に空気包合噴射させ、噴射管を回転又は反転させながら引き上げることにより、上側の噴射ノズルから噴射される超高圧水（空気包合噴射の超高圧水）が構成する超高圧噴流体と、下側の噴射ノズルから噴射される超高圧硬化材液（空気包合噴射の超硬化材液）とで地盤を切削し、スライムをリフト作用により地表に排出させると同時に円柱状の固結体を造成する。
【０００６】
上記のように、超高圧噴射工法に使用する噴射管の先端部に取り付けられているモニター装置（噴射管の先端部に取り付けられる噴射装置）には、超高圧水や超高圧硬化材液等の超高圧液体を線状に噴射させて超高圧噴流体を構成するための噴射ノズル（モニター）が普通１つ設けられており、噴射ノズルの軸芯が噴射管の管軸芯線と平行な向きに見て噴射管の中心線と重なるように、噴射管の中心線上で半径方向に取り付けられているが、２つの噴射ノズルを、各噴射ノズルの軸芯が噴射管の管軸芯線と平行な向きに見て噴射管の１本の中心線と重なるように、噴射管の中心線上で半径方向逆向きに取り付けたものもある。また超高圧噴射工法の種類によって使用される噴射管、所謂ロッドが単管、二重管、三重管と異なり、その管径（外径）も単管、二重管、三重管の順に太くなる。
【０００７】
【発明が解決しようとする課題】
超高圧噴射工法においては理論や実験結果にしたがった良質の噴射ノズルを使用することが必要である。その良質の噴射ノズルＮは図５に示すような型になっている。即ち、ノズル全長ｗがノズル出口直径Ｄの１５〜２０倍、ノズル入り口通路Ｎａとノズル出口通路Ｎｂの間の絞り部Ｎｃの絞り角Ｂが１３°、ノズル出口通路Ｎｂの長さＷがノズル出口直径Ｄの３〜４倍である。また仕上げも機械的に最高級の仕上げで、非常に精密である。このような良質の噴射ノズルＮを使用することにより、図６の（ａ）に示すように、超高圧噴流液を液体の束として正しく確保でき、地盤の切削に有効に働く超高圧噴流体を構成できるが、噴射ノズルの全長が不足したり、傷ついたりした場合には、図６の（ｂ）に示すように、超高圧噴流液は割れてしまい、有効な超高圧噴流体を構成できない。
【０００８】
そして、ノズル出口直径Ｄは２ｍｍ程度であるから、良質な噴射ノズルＮは全長ｗが３０〜４０ｍｍ程度と長くなるが、従来のモニター装置は、噴射ノズルを噴射管の中心線上に取り付けているため、噴射管が小径の場合、良質な噴射ノズルＮに比べて全長が短い簡易な噴射ノズルしか使用できず、固結体の造成範囲（地盤の改良範囲）の拡大や造成時間（地盤の改良時間）の短縮による工期の短縮を図り難いという問題があった。
【０００９】
したがって本発明は、噴射管が小径の場合でも、良質な噴射ノズルＮを使用できるようにして、工期の短縮を容易に図り得る地盤改良工法に使用するモニター装置を提供することを主たる目的としている。
【００１０】
【課題を解決するための手段】
上記の目的を達成する本発明の地盤改良工法に使用するモニター装置は、超高圧噴流体により地盤を切削する工程を含む地盤改良工法に使用するモニター装置であって、超高圧液体を逆方向に噴射する２つの噴射ノズルを噴射管に設けると共に、２つの噴射ノズルを、各噴射ノズルの軸芯が噴射管の管軸芯線と平行な向きに見て噴射管の中心線と重ならないように、噴射管の管側部に取り付け、噴射管の超高圧液体供給管路を周方向に噴射ノズル数と同数に仕切る隔壁を設け、該隔壁で仕切られた各仕切り管路を噴射ノズルの入り口にそれぞれ連通させ、噴射管の先端部の周側壁に上記各仕切り管路内にそれぞれ張り出す２つのノズル取り付けブロックを一体に設け、この２つのノズル取り付けブロックを前記隔壁に沿って逆方向から各仕切り管路内に張り出させると共に、各ノズル取り付けブロックに上記仕切り管路の先端部に行くにしたがって張り出し量を多くする傾斜張り出し部を設けて、各仕切り管路をその先端部に行くにしたがって徐々に狭くするように形成するとともに、各仕切り管路内に最も多く張り出している各ノズル取り付けブロックの先端部分に噴射ノズルの入り口側端部が位置するように各噴射ノズルを配設したことを特徴とする（請求項１に記載の発明）。
【００１１】
【００１２】
【００１３】
前述の単管式超高圧噴射工法や二重管式超高圧噴射工法による地盤改良工法に使用するモニター装置の場合は、噴射ノズルより上流側から削孔水を流入させて噴射ノズルより下流側の削孔水噴射口に供給する内管路を噴射管の中心部に設けると共に、前記内管路の流入口を塞ぐ球形の止水栓を受け止める漏斗形の受け部材を噴射ノズルより上流側の噴射管内に設け、前記受け部材の中心部に前記内管路の流入口を開口させ、前記流入口の周囲受け面に削孔水や超高圧液体を通過させる多数の孔を設ける（請求項２に記載の発明）。
【００１４】
【発明の作用・効果】
【００１５】
請求項１に記載の発明では、噴射ノズルを噴射管の中心線上を避けて管側部に取り付ける構成であるから、噴射管が小径の場合でも、良質な噴射ノズルを使用することができ、しかも２つ使用することができ、地盤の切削に有効に働く２つの超高圧噴流体で地盤を２箇所同時に切削できるため、工期の短縮を容易に図ることができる。
【００１６】
また、単一の噴射ノズルでは超高圧液体の噴射反力によって噴射管の特に先端部にぶれを生じるが、２つの噴射ノズルから逆方向に超高圧液体を噴射する構成であるから、各噴射ノズルで互いの噴射反力を相殺でき、噴射管のぶれも防止できる。尚、噴射管のぶれを防止する点で、２つの噴射ノズルは、噴射管の管側部に等間隔に取り付けることが好ましく、また一つの噴射ノズルを噴射管の管軸芯を中心に１８０°回転させたとき、噴射管の管軸芯線と平行な向きに見てもう一つの噴射ノズルと重なる位置、即ち点対称位置に各噴射ノズルを取り付けることがより好ましい。
【００１７】
２つの噴射ノズルを噴射管に設けるモニター装置の場合は、単一の噴射ノズルを設ける場合に比べて超高圧液体の吐出量が多くなり、噴射管が小径になるにしたがって乱流を生じ易くなるが、噴射管の超高圧液体供給通路を噴射ノズル数と同数（２つ）に仕切る隔壁を設け、一つの仕切り通路に対して一つの噴射ノズルの入り口を連通させる構成であるから、超高圧液体の吐出量が多くなっても乱流を防止できる。
【００１８】
請求項２に記載の発明では、噴射ノズルより下流側に設ける削孔水噴射口を噴射ノズルより上流側で塞ぐ構成であるから、小径の噴射管に良質な噴射ノズルを取り付けた場合でも、従来と同様にスチールボール等の球形の止水栓を噴射管に投入することで削孔水噴射口を塞ぐことができる。この結果、単管式超高圧噴射工法や二重管式超高圧噴射工法による地盤改良工法を従来と同じ工程で行うことができる。
【００１９】
【発明の実施の形態】
以下本発明の実施例を図面に基づいて説明する。図１は本発明に係るモニター装置の縦断面図、図２は同モニター装置の横断面図であり、このモニター装置１はＣＣＰ工法等の単管式超高圧噴射工法による地盤改良工法にて地中に円柱状の固結体を造成する際に使用する噴射管２の先端部に取り付けるもので、噴射管２は外径が５５ｍｍ程度で定長寸の鋼管（単管）である噴射管材３を先端部のモニター装置１から一方向に１段、２段、・・・ｎ段と一直線状に接続し、かつ図３に示すようにモニター装置１と反対側の噴射管２の端部となる最終段の噴射管材３の端部に単管用のスイベル４を取り付けて構成し、超高圧ポンプ（図示省略）からの圧力３ＭＰａ程度の高圧削孔水と圧力２０〜４０ＭＰａ程度の地盤切削兼改良用の超高圧液体であるセメント系の超高圧硬化材液（セメントミルク）とをスイベル４に設けた単一の注入口５から択一的に噴射管２内に注入して先端部のモニター装置１から噴射するように構成している。
【００２０】
尚、スイベル４の端部に噴射管２をクレーン等で吊持するためのフック部６を一体に設けている。
【００２１】
図１、図２に示す如く、前記モニター装置１は図５に示した良質の噴射ノズルＮの条件を満たす全長が長い２つの噴射ノズルＮ１，Ｎ２と、この噴射ノズルＮ１，Ｎ２を設けるモニター管７とで構成するもので、モニター管７は噴射管材３・・・と同じ外径を有し長さが噴射管材３・・・より短尺に形成される。このモニター管７の一端部に噴射管材３（１段目の噴射管材３）の端部を一直線状に接続するための接続手段８を設け、噴射管３の先端部をモニター管７によって構成すると共に、噴射管材３との接続端部と反対側のモニター管７の先端部に噴射管材３及びモニター管７と同じ外径を有する短筒形状の削孔器具であるメタルクラウン９の取り付け端部を一直線状に接続するための接続手段１０を設け、モニター管７の先端、即ち噴射管２の最先端にメタルクラウン９を取り付けるように構成している。
【００２２】
尚、本実施例ではモニター管７の一端部に設ける噴射管材３に対する接続手段８として、噴射管材３の端部内周面に形成された雌ねじ８ａを螺着させる雄ねじを示し、モニター管７と噴射管材３の端部同士をねじ込み式で直結する形態を示したが、この場合のねじは雌雄逆でもよく、またソケット型の管継ぎ手等を使用してモニター管７と噴射管材３の端部同士を間接的に接続させる場合には、その管継ぎ手の接続端部に対応した形態の接続手段８となる。さらにモニター管７の先端部に設けるメタルクラウン９に対する接続手段１０として、メタルクラウン９の取り付け端部外周面に形成された雄ねじ１０ａを螺着させる雌ねじを示し、モニター管７とメタルクラウン９の端部同士をねじ込み式で直結する形態を示したが、この場合のねじも雌雄逆でもよく、またソケット型の管継ぎ手等を使用してモニター管７とメタルクラウン９の端部同士を間接的に接続させる場合には、その管継ぎ手の接続端部に対応した形態の接続手段１０となる。
【００２３】
また、モニター管７には噴射ノズルＮ１，Ｎ２より下流側に管底１１を設け、この管底１１の中心部に削孔水噴射口１２を開口形成している。この削孔水噴射口１２にモニター管７内の中心部に管軸方向に沿って設ける内管１３の先端を嵌合させ、噴射ノズルＮ１，Ｎ２より上流側から高圧削孔水を流入させて噴射ノズルＮ１，Ｎ２より下流側の削孔水噴射口１２に供給する内管路１４をモニター管７内の中心部に管軸方向に沿って設けると共に、その内管路１４の周囲に管底１１で行き止まりとなり先端を閉鎖した外管路１５を設けている。
【００２４】
尚、管底１１はモニター管７の先端より所定寸法管軸芯方向内側に入った位置に上げ底状態で設け、この管底１１より先部のモニター管７の先端部にメタルクラウン９に対する前記接続手段１０を設けている。
【００２５】
さらに、噴射管２の内径より小径で内管１３の内径より大径の球形の止水栓であるスチールボール１６を備え、削孔水噴射口１２に嵌合した内管１３の先端と反対側の端部開口、即ち内管路１４の流入口１４ａにスチールボール１６の一部を嵌合させることでこの流入口１４ａを塞ぐように構成している。このスチールボール１６はスイベル４を取り外した状態の噴射管２の端部開口からこの噴射管２内に投入し先端部のモニター管７内に入れるもので、スチールボール１６を受け止める漏斗形の受け部材１７をモニター管７の管軸芯方向内側に行くにしたがって縮径する姿勢で噴射ノズルＮ１，Ｎ２より上流側のモニター管７内に設け、この受け部材１７の中心部に内管路１４の流入口１４ａを開口形成すると共に、流入口１４ａの周囲受け面１７ａに超高圧硬化材液を通過させて外管路１５に流入させる多数の孔１８・・・を設けている。また、モニター管７に外管路１５を周方向に噴射ノズル数と同数（２つ）に仕切る隔壁を設けるもので、モニター管７に２つの噴射ノズルＮ１，Ｎ２を設けるので、２枚の隔壁１９ａ，１９ｂをモニター管７の外管路１５内における１８０°対称位置に張設し、モニター管７の管軸芯線と平行な向きに見てモニター管７の１本の中心線Ｘ上に設けられる前記２枚の隔壁１９ａ，１９ｂによって外管路１５を周方向に２等分し、その一方の仕切り通路である第１の半外管路１５ａに一方の噴射ノズルＮ１の入り口を連通させ、他方の仕切り通路である第２の半外管路１５ｂに他方の噴射ノズルＮ２の入り口を連通させている。
【００２６】
そして、図５に示した良質の噴射ノズルＮの条件を満たす２つの噴射ノズルＮ１，Ｎ２をモニター管７に設けるために、この２つの噴射ノズルＮ１，Ｎ２は、各噴射ノズルＮ１，Ｎ２の軸芯Ｘ１，Ｘ２がモニター管７の管軸芯線と平行な向きに見て前記１本の中心線Ｘに対して重ならないように、モニター管７の管側部に、管軸芯に対して直角方向逆向きで取り付けるもので、モニター管７の周側壁に各半外管路１５ａ，１５ｂ内に一つずつ張り出す合計２つのノズル取り付けブロック２０ａ，２０ｂを一体に設け、この２つのノズル取り付けブロック２０ａ，２０ｂを前記隔壁１９ａ，１９ｂに沿って逆方向から各半外管路１５ａ，１５ｂ内に張り出すと共に、各ノズル取り付けブロック２０ａ，２０ｂに半外管路１５ａ，１５ｂの先端部に行くにしたがって張り出し量を多くする傾斜張り出し部２１ａ，２１ｂを設け、各ノズル取り付けブロック２０ａ，２０ｂを各半外管路１５ａ，１５ｂ内にこの先端部で最も多く張り出すように形成し、各半外管路１５ａ，１５ｂをこの先端部に行くにしたがって徐々に狭くするように形成している。また、各半外管路１５ａ，１５ｂ内に最も多く張り出している各ノズル取り付けブロック２０ａ，２０ｂの先端部分にノズル収容凹部２２ａ，２２ｂを設け、各ノズル取り付けブロック２０ａ，２０ｂの先端部分をモニター管７の外周面から前記隔壁１９ａ，１９ｂに沿って逆方向に所定寸法凹めて各ノズル収容凹部２２ａ，２２ｂを形成し、モニター管７の管軸芯線と平行な向きに見て前記１本の中心線Ｘに直交する方向の各ノズル収容凹部２２ａ，２２ｂの底面２３ａ，２３ｂに半外管路１５ａ，１５ｂの先端内部に貫通するねじ孔２４ａ，２４ｂを形成し、各噴射ノズルＮ１，Ｎ２の入り口側端部の雄ねじ部２５ａ，２５ｂをねじ孔２４ａ，２４ｂにねじ込むことにより、２つの噴射ノズルＮ１，Ｎ２を、ノズル収容凹部２２ａ，２２ｂ内に収容してモニター管７の外径内に収めかつこの入り口を半外管路１５ａ，１５ｂの先端部に連通させた状態で、モニター管７の管軸芯線と平行な向きに見て各噴射ノズルＮ１，Ｎ２の軸芯Ｘ１，Ｘ２が前記１本の中心線Ｘに対して重ならないモニター管７の中心線上を避けた管側部に、管軸芯に対して直角方向逆向きで取り付け、超高圧硬化材液を２つの噴射ノズルＮ１，Ｎ２からモニター管７の外側にこの管軸芯に対して直角方向逆向きに噴射させ、この２つの噴射ノズルＮ１，Ｎ２から噴射される超高圧硬化材液が構成する図６の（ａ）に示すような地盤の切削に有効に働く２つの超高圧噴流体でモニター管７の周囲の地盤を切削するように構成している。
【００２７】
各噴射ノズルＮ１，Ｎ２は、一つの噴射ノズルＮ１をモニター管７の管軸芯を中心に１８０°回転させたとき、モニター管７の管軸芯線と平行な向きに見てもう一つの噴射ノズルＮ２と重なる位置、即ち点対称位置に取り付けられている。
【００２８】
尚、図中２６ａ，２６ｂは各噴射ノズルＮ１，Ｎ２の入り口側端部の雄ねじ部２５ａ，２５ｂとこれをねじ込むモニター管７側のねじ孔２４ａ，２４ｂとの隙間を塞ぐシール部材である。また本実施例では２つの噴射ノズルＮ１，Ｎ２をモニター管７にこの管軸芯に対して直角な一平面上で取り付けたが、２つの噴射ノズルＮ１，Ｎ２をモニター管７の軸芯方向に所定の間隔を設けて（段差を付けて）取り付けてもよい。
【００２９】
次に、図４（ａ）〜（ｅ）は上記のモニター装置１を先端部に取り付けた噴射管２（単管）を使用するＣＣＰ工法等の単管式超高圧噴射工法による本発明に係るモニター装置を使用する地盤改良工法にて地中に円柱状の固結体Ｐを垂直に造成する施工手順を示す説明図であり、同図（ａ）は据付工程、同図（ｂ）は削孔工程、同図（ｃ）は噴射テスト工程、同図（ｄ）は切削・造成工程、同図（ｅ）は引き抜き・洗浄工程を示し、以下各工程を説明する。
【００３０】
ａ．据付工程
ボーリングマシンＭを所定の施工位置に移動し据え付け、１本の噴射管材３の下端に上記のモニター装置２のモニター管７を取り付け、また上端にスイベル４を取り付け、さらにモニター管７の下端にメタルクラウン９を取り付けた最短の噴射管２を地上に垂直に立て、スイベル４の注入口５を超高圧ポンプの吐出口に接続する。
【００３１】
ｂ．削孔工程
据付工程でボーリングマシンＭによって所定の施工位置に垂直に立てられた最短の噴射管２内にこの上端に取り付くスイベル４の注入口５から超高圧ポンプからの圧力３ＭＰａ程度の高圧削孔水を注入し、噴射管２の下端削孔水噴射口１２からこの管軸芯方向下向きに高圧削孔水を噴射させ、ボーリングマシンＭによって地質条件に応じた速度で噴射管２をこの管軸芯回りで回転又は反転駆動させながら地質条件に応じた速度で下降させて削孔を開始する。以降、削孔深度に応じて噴射管材３を２段、３段、・・・ｎ段と継ぎ足して噴射管２を地中に伸ばしながら削孔を行い、計画深度まで削孔する。
【００３２】
ここで、噴射管２内にこの上端から注入された高圧削孔水は、噴射管２の下端部を構成するモニター管１内にこの上端開口から流入し、このモニター管１内において、噴射ノズルＮ１，Ｎ２より上流側に開口形成された流入口１４ａから内管路１４に流入し、モニター管７の中心部を通過して、噴射ノズルＮ１，Ｎ２より下流側の管底１１に開口形成された削孔水噴射口１２から噴射され、メタルクラウン９による削孔を助ける。またモニター管１内に流入した高圧削孔水は、受け部材１７の受け面１７ａに設けられた多数の孔１８・・・を通過して、内管路１４の周囲の外管路１５にも流入し、各噴射ノズルＮ１，Ｎ２からも噴射され、削孔を助けるが圧力は低く地盤切削能力はない。
【００３３】
ｃ．噴射テスト工程
削孔後、噴射管２の上端からスイベル４を取り外し、その端部開口から噴射管２内にスチールボール１６を投入し、噴射管２内を落下させて各噴射ノズルＮ１，Ｎ２より下流側の管底１１の中心部に開口形成された削孔水噴射口１２を塞ぎ、再び噴射管２の上端にスイベル４を取り付け、このスイベル４の注入口５を超高圧ポンプの吐出口に接続した状態で、噴射管２を試行的に設定された速度で回転又は反転させながら試行的に設定された速度で引き上げる。この際、削孔水を硬化材液に切り換えると共に、超高圧ポンプの吐出圧を２０〜４０ＭＰａ程度に上昇させ、この超高圧ポンプからの超高圧硬化材液をスイベル４の注入口５から噴射管２内に注入し、噴射管２下端部の各噴射ノズルＮ１，Ｎ２から超高圧硬化材液を噴射させて噴射テストをする。この噴射テストが順調なら造成工程に移行する。
【００３４】
ここで、噴射管２内に投入されたスチールボール１６は、噴射管２の下端部を構成するモニター管１内にこの上端開口から入り、噴射ノズルＮ１，Ｎ２より上流側のモニター管７内に設けられた漏斗形の受け部材１７によって受け止められ、この受け部材１７の中心部に開口形成された内管路１４の流入口１４ａに一部が嵌合してこの流入口１４ａを塞ぐことで、噴射ノズルＮ１，Ｎ２より下流側の管底１１の中心部に開口形成された削孔水噴射口１２を塞ぐ。これによって、小径の噴射管２に良質な噴射ノズルＮ１，Ｎ２を取り付けた場合でも、従来と同様にスチールボール１６等の球形の止水栓を噴射管２に投入することで削孔水噴射口１２を塞ぐことができるのである。
【００３５】
スチールボール１６によって内管路１４の流入口１４ａが塞がれると、噴射管２内にこの上端から注入された超高圧硬化材液は、噴射管２の下端部を構成するモニター管１内にこの上端開口から流入し、このモニター管２内において、噴射ノズルＮ１，Ｎ２より上流側の受け部材１７の受け面１７ａに設けられた多数の孔１８・・・を通過して、内管路１４に流入することなくこの内管路１４の周囲の外管路１５にのみ流入し、各噴射ノズルＮ１，Ｎ２から噴射される。
【００３６】
ｄ．切削・造成工程
所定の噴射管２の回転又は反転速度と引き上げ速度を維持すると共に、超高圧ポンプから噴射管２内への超高圧硬化材液の注入を連続的に行い、噴射管２下端部の各噴射ノズルＮ１，Ｎ２から超高圧硬化材液を連続噴射させ、この各噴射ノズルＮ１，Ｎ２から噴射される超高圧硬化材液が構成する２つの超高圧噴流体で噴射管２の周囲の地盤を切削すると共に攪拌、混練して円柱状の固結体（地中パイル）Ｐを造成域上限まで造成する。
【００３７】
ここで、各噴射ノズル１、Ｎ２は、モニター管７の管軸芯線と平行な向きに見て各噴射ノズルＮ１，Ｎ２の軸芯Ｘ１，Ｘ２が前記１本の中心線Ｘに対して重ならないモニター管７の中心線上を避けた管側部に、管軸芯に対して直角方向逆向きで取り付けるから、超高圧噴射工法のうち最も小径の噴射管２にでも、噴射ノズルとして図５に示した良質の噴射ノズルＮの条件を満たす全長が長い噴射ノズルをＮ１，Ｎ２を使用する（取り付ける）ことができ、しかも２つ使用する（取り付ける）ことができる。この結果、噴射ノズルＮ１，Ｎ２から噴射される超高圧硬化材液が構成する２つの超高圧噴流体は、図６の（ａ）に示すような、地盤の切削に有効に働く超高圧噴流体となり、従来の全長が短い簡易な噴射ノズルを使用する場合に比べて、固結体Ｐの造成範囲（地盤の改良範囲）が拡大されかつ造成時間（地盤の改良時間）も短縮され、工期を短縮することができるのである。
【００３８】
また、単一の噴射ノズルでは超高圧硬化材液の噴射反力によって噴射管２の特に先端部（モニター装置１部）にぶれを生じるが、２つの噴射ノズルＮ１，Ｎ２から逆方向に超高圧液体を噴射するから、各噴射ノズルＮ１，Ｎ２で互いの噴射反力を相殺でき、噴射管２のぶれも防止できるのである。
【００３９】
また、二重管や三重管式超高圧噴射工法の場合は、地盤を切削する超高圧液体を噴射させる噴射ノズルの出口の周囲に圧縮空気用の噴射ノズルが設けられ、超高圧液体用の噴射ノズルの出口を噴射管（二重管，三重管）の外周面から突出させても、その周囲の圧縮空気用の噴射ノズルが超高圧液体用の噴射ノズルの出口の保護カバーの役目を果たし、削孔時に超高圧液体用の噴射ノズルを傷つけることはないが、単管式超高圧噴射工法の場合には、圧縮空気用の噴射ノズルは設けられないため、各噴射ノズルＮ１，Ｎ２の出口を噴射管２（単管）の外周面から突出させると、削孔時に各噴射ノズルＮ１，Ｎ２を傷つける恐れがあるが、各噴射ノズルＮ１，Ｎ２をノズル収容凹部２２ａ，２２ｂ内に収容してモニター管７の外径内に収めているから、この噴射ノズルＮ１，Ｎ２を削孔時に傷つるのを防止できる。
【００４０】
さらに、２つの噴射ノズルＮ１，Ｎ２を１本の噴射管２に設ける場合は、単一の噴射ノズルを設ける場合に比べて超高圧硬化材液の吐出量が多くなり、噴射管２が小径になるにしたがって乱流を生じ易くなるが、噴射管２内にこの上端から注入された超高圧硬化材液は、噴射管２の下端部を構成するモニター管７内にこの上端開口から流入し、このモニター管２内において、噴射ノズルＮ１，Ｎ２より上流側の受け部材１７の受け面１７ａに設けられた多数の孔１８・・・を通過して、内管路１４の周囲の一つの外管路１５が２枚の隔壁１９ａ，１９ｂによって周方向に２等分に仕切られて形成された２つの半外管路１５ａ，１５ｂに流入し、その一つの半外管路１５ａ，１５ｂに対して一つの噴射ノズルＮ１，Ｎ２の入り口を連通させ、各噴射ノズルＮ１，Ｎ２から超高圧硬化材液を噴射させるから、各半外管路１５ａ，１５ｂ内では超高圧硬化材液の流れが一方向に安定し、超高圧硬化材液の吐出量が多くなり、小径の噴射管２であっても乱流を防止できるのである。
【００４１】
ｅ．引き抜き・洗浄工程
噴射管２を地上に引き抜き、この噴射管２の一段目の噴射管材２ａからモニター管７を取り外してスチールボール１６を取り出し、再びモニター管７を噴射管２の一段目の噴射管材２ａに接続した状態で、超高圧硬化材液を清水に切り換えると共に、超高圧ポンプの吐出圧を所定圧力に落とし、この超高圧ポンプからの清水をスイベル４の注入口５から噴射管２内に注入し、噴射管２下端部の各噴射ノズルＮ１，Ｎ２及び削孔水噴射口１２から清水を噴射させ、この噴射で噴射管２内や噴射ノズルＮ１，Ｎ２内の残留硬化材液を全て排出させ、洗浄する。
【００４２】
この後、次の造成地点にボーリングマシンＭを移動据え付けし、同様の手順で地中に円柱状の固結体Ｐを造成するものである。
【００４３】
尚、本実施例は、超高圧液体である超高圧硬化材液を逆方向に噴射する２つの噴射ノズルＮ１，Ｎ２を噴射管２の先端部を構成するモニター管７に設け、２つの噴射ノズルＮ１，Ｎ２を、各噴射ノズルＮ１，Ｎ２の軸芯Ｘ１，Ｘ２が前記モニター管７の管軸芯線と平行な向きに見てモニター管７の中心線と重ならないように、モニター管７の管側部に取り付け、前記噴射ノズルＮ１，Ｎ２から噴射される超高圧硬化材液が構成する２つの超高圧噴流体で地盤を切削し、地中に円柱状の固結体Ｐを造成するＣＣＰ工法等の単管式超高圧噴射工法による地盤改良工法と、それに使用するモニター装置１、即ち超高圧液体である超高圧硬化材液を逆方向に噴射する２つの噴射ノズルＮ１，Ｎ２を噴射管２の先端部を構成するモニター管７に設け、２つの噴射ノズルＮ１，Ｎ２を、各噴射ノズルＮ１，Ｎ２の軸芯Ｘ１，Ｘ２が前記モニター管７の管軸芯線と平行な向きに見てモニター管７の中心線と重ならないように、モニター管７の管側部に取り付けたモニター装置１を示したが、本実施例に示した噴射ノズルＮ１，Ｎ２のうち何れか一つを省略し、これに伴って各隔壁１９ａ，１９ｂも省略した場合、１つの噴射ノズルＮ１から超高圧硬化材液を一方向に噴射し、噴射ノズルＮ１から噴射される超高圧硬化材液が構成する一つの超高圧噴流体で地盤を切削し、地中に円柱状の固結体Ｐを造成する。また本実施例で示した２つの噴射ノズルＮ１，Ｎ２に、これらと同様に図５に示した良質の噴射ノズルＮの条件を満たす全長が長い噴射ノズルＮ３を１つ追加して設け、これら３つの噴射ノズルＮ１，Ｎ２，Ｎ３を１２０°間隔で、各噴射ノズルＮ１，Ｎ２，Ｎ３の軸芯Ｘ１，Ｘ２，Ｘ３が前記モニター管７の管軸芯線と平行な向きに見てモニター管７の中心線と重ならないように、モニター管７の管側部に取り付け、これに伴って外管路１５も３枚の隔壁１９ａ，１９ｂ，１９ｃによって周方向に３等分に仕切った場合、又は、本実施例で示した２つの噴射ノズルＮ１，Ｎ２に、これらと同様に図５に示した良質の噴射ノズルＮの条件を満たす全長が長い噴射ノズルＮ３，Ｎ４を２つ追加して設け、これら４つの噴射ノズルＮ１，Ｎ２，Ｎ３，Ｎ４を９０°間隔で、各噴射ノズルＮ１，Ｎ２，Ｎ３の軸芯Ｘ１，Ｘ２，Ｘ３，Ｘ４が前記モニター管７の管軸芯線と平行な向きに見てモニター管７の中心線と重ならないように、モニター管７の管側部に取り付け、これに伴って外管路１５も４枚の隔壁１９ａ，１９ｂ，１９ｃによって周方向に４等分に仕切った場合、３つ又は４つの噴射ノズル（Ｎ１，Ｎ２，Ｎ３）又は（Ｎ１，Ｎ２，Ｎ３，Ｎ４）から超高圧硬化材液を異方向に噴射し、噴射ノズル（Ｎ１，Ｎ２，Ｎ３）又は（Ｎ１，Ｎ２，Ｎ３，Ｎ４）から噴射される超高圧硬化材液が構成する３つ又は４つの超高圧噴流体で地盤を切削し、地中に円柱状の固結体Ｐを造成する。
【００４４】
上記から明らかなように、本実施例は、本発明の噴射ノズルの数が２つに限定されず２つ以上の複数に限定する上位概念の発明、即ち「超高圧噴流体により地盤を切削する工程を含む地盤改良工法において、超高圧液体を異方向に噴射する複数の噴射ノズルを噴射管に設けると共に、複数の噴射ノズルを、各噴射ノズルの軸芯が噴射管の管軸芯線と平行な向きに見て噴射管の中心線と重ならないように、噴射管の管側部に取り付け、前記噴射ノズルから噴射される超高圧液体が構成する複数の超高圧噴流体で地盤を切削することを特徴とする地盤改良工法。」並びに「超高圧液体を異方向に噴射する複数の噴射ノズルを噴射管に設けると共に、複数の噴射ノズルを、各噴射ノズルの軸芯が噴射管の管軸芯線と平行な向きに見て噴射管の中心線と重ならないように、噴射管の管側部に取り付けた前記地盤改良工法に使用するモニター装置。」を一義的に見出す実施例として活用でき、また本発明の噴射ノズルの数が限定されない上記の上位概念よりさらに上位の発明、即ち「超高圧噴流体により地盤を切削する工程を含む地盤改良工法において、超高圧液体を噴射する噴射ノズルを噴射管に設けると共に、噴射ノズルを、噴射ノズルの軸芯が噴射管の管軸芯線と平行な向きに見て噴射管の中心線と重ならないように、噴射管の管側部に取り付け、前記噴射ノズルから噴射される超高圧液体が構成する超高圧噴流体で地盤を切削することを特徴とする地盤改良工法。」並びに「超高圧液体を噴射する噴射ノズルを噴射管に設けると共に、噴射ノズルを、噴射ノズルの軸芯が噴射管の管軸芯線と平行な向きに見て噴射管の中心線と重ならないように、噴射管の管側部に取り付けた前記地盤改良工法に使用するモニター装置。」を一義的に見出す実施例として活用でき、これら上位概念の発明が本発明と同様の目的を達成できることは言うまでもない。
【００４５】
上記のようにＣＣＰ工法等の単管式超高圧噴射工法による地盤改良工法に使用するモニター装置１を実施例に挙げて本発明及びその上位概念の発明を説明したが、本実施例の噴射管２（単管）より太い外径が６０ｍｍ程度の噴射管（二重管）を使用するＪＳＧ工法等の二重管式超高圧噴射工法、本実施例より太い外径が９０ｍｍ程度の噴射管（三重管）を使用するＣＪＧ工法やＲＪＰ工法等の三重管式超高圧噴射工法、これら工法に類似する他の工法も含め、超高圧噴流体により地盤を切削する工程を含む地盤改良工法であれば、超高圧噴流体を構成するために超高圧水や超高圧硬化材液等の超高圧液体を噴射する噴射ノズルについて本発明及びその上位概念の発明を適用できる。
【図面の簡単な説明】
【図１】本発明に係るモニター装置の縦断面図
【図２】同モニター装置の横断面図
【図３】噴射管のスイベル部の外観図
【図４】本発明に係るモニター装置を使用する地盤改良工法の施工手順を示す説明図
【図５】良質な噴射ノズルの説明図
【図６】超高圧噴射流体の説明図
【符号の説明】
１モニター装置
２噴射管
４スイベル
７モニター管（噴射管の先端部）
１１管底
１２削孔水噴射口
１４内管路
１４ａ流入口
１５外管路
１５ａ，１５ｂ半外管路
１６スチールボール（止水栓）
１７受け部材
１７ａ受け面
１８孔
１９ａ，１９ｂ隔壁
２０ａ，２０ｂノズル取り付けブロック
２２ａ，２２ｂノズル収容凹部
Ｎ１、Ｎ２噴射ノズル
Ｍボーリングマシン
Ｐ固結体[0001]
[Technical field to which the invention belongs]
The present invention provides a ground improvement work including a step of cutting the ground with an ultrahigh pressure jet fluid. To the law It relates to the monitoring device to be used.
[0002]
[Prior art]
As a ground improvement method including a step of cutting the ground with an ultra-high pressure jet fluid, an ultra-high pressure jet method is known. This super high pressure injection method includes single pipe type super high pressure injection method such as CCP method, double pipe type super high pressure injection method such as jet grout method (JSG method), column jet grout method (CJG method) and rosin jet pile method. There are triple pipe type ultra-high pressure injection methods such as (RJP method).
[0003]
In the case of standard construction, the single-pipe ultra-high pressure injection method uses a cement-based ultra-high-pressure hardening material liquid (cement milk) from the injection nozzle provided at the tip of the injection pipe (single pipe) inserted into the ground. The ground is cut with an ultra-high pressure jet fluid composed of the ultra-high pressure hardened material liquid sprayed from the spray nozzle, and then stirred and kneaded to form a cylindrical solid. Create a knot (underground pile). In addition, in the case of water injection construction, super-high pressure water is injected into the ground from the injection nozzle provided at the tip of the injection pipe inserted into the ground, and the injection pipe is pulled up while rotating or reversing. After cutting the ground with ultra-high pressure jet fluid composed of ultra-high pressure water sprayed from the nozzle, insert the spray pipe into the ground again, and spray cement-based ultra-high pressure hardening material liquid (cement milk) from the spray nozzle Then, by pulling up while rotating or reversing the injection tube, the columnar solid body (underground pile) is stirred and kneaded with the ultra-high pressure jet fluid composed of the ultra-high pressure curing material liquid injected from the injection nozzle. Create.
[0004]
In the double-pipe ultra-high pressure injection method, cement-based ultra-high-pressure hardening liquid (cement milk) is injected into the ground from the injection nozzle provided at the tip of the injection pipe (double pipe) inserted into the ground. At the same time, the compressed air is jetted from an air nozzle provided around the jet nozzle of the ultra-high pressure curable material liquid, and the jet tube is pulled up while rotating or reversing, thereby being ejected from the jet nozzle ( The ground is cut with an ultra-high pressure jet fluid composed of an ultra-high pressure hardening liquid with air in the surroundings, and slime is discharged to the ground surface by a lifting action, and at the same time, a cylindrical solid body is formed.
[0005]
Of the triple-pipe ultra-high pressure injection method, the column jet grouting method is a method of injecting ultra-high pressure water into the ground from the injection nozzle provided at the tip of the injection pipe (triple pipe) inserted into the ground. Ultra high-pressure water (super high-pressure water with air around it) that is injected from the injection nozzle is constructed by injecting compressed air from the air nozzle provided around the nozzle and pulling it up while rotating or reversing the injection pipe The ground is cut with an ultra-high pressure jet fluid, and slime is discharged to the ground surface by a lifting action and simultaneously filled with cement-based high-pressure hardening liquid (cement milk) from an injection nozzle different from the injection nozzle of ultra-high pressure water, A columnar solid is formed. The rosin jet pile method is a method of injecting ultra-high pressure water into the ground from the upper injection nozzle among the injection nozzles attached to the top and bottom of the injection pipe (triple pipe) inserted into the ground, Ultra high-pressure water sprayed from the upper spray nozzle by injecting cement-based high-pressure hardening liquid (cement milk) into the ground from the lower spray nozzle and pulling it up while rotating or reversing the spray pipe (Sky The ground is cut with an ultra-high-pressure jet fluid composed of super-high-pressure water (air-enclosed injection) and an ultra-high-pressure hardening material liquid (air-enclosed injection super-hardening material liquid) injected from the lower injection nozzle, The slime is discharged to the ground surface by a lifting action, and at the same time, a cylindrical solid body is formed.
[0006]
As described above, the monitoring device (injection device attached to the tip of the injection tube) attached to the tip of the injection tube used in the ultra-high pressure injection method includes ultra-high pressure water, ultra-high pressure curable material liquid, etc. An injection nozzle (monitor) is usually provided to form an ultra-high-pressure jet fluid by jetting ultra-high pressure liquid in a line, and the axis of the injection nozzle is oriented parallel to the tube axis of the injection pipe It is attached in the radial direction on the center line of the injection pipe so that it overlaps the center line of the injection pipe as seen, but the two injection nozzles are oriented with the axis of each injection nozzle parallel to the pipe axis of the injection pipe Some of them are mounted in the opposite radial direction on the center line of the injection tube so as to overlap one center line of the injection tube. Also, the so-called rods used by the type of ultra-high pressure injection method, so-called rods, are different from single tubes, double tubes, and triple tubes, and the tube diameter (outer diameter) increases in the order of single tubes, double tubes, and triple tubes. .
[0007]
[Problems to be solved by the invention]
In the ultra-high pressure injection method, it is necessary to use a high-quality injection nozzle according to the theory and experimental results. The high quality injection nozzle N has a shape as shown in FIG. That is, the total nozzle length w is 15 to 20 times the nozzle outlet diameter D, the throttle angle Nc of the throttle portion Nc between the nozzle inlet passage Na and the nozzle outlet passage Nb is 13 °, and the length W of the nozzle outlet passage Nb is the nozzle outlet. 3 to 4 times the diameter D. The finishing is mechanically the finest and very precise. By using such a high-quality injection nozzle N, as shown in FIG. 6 (a), an ultrahigh pressure jet fluid that can ensure the ultrahigh pressure jet liquid correctly as a bundle of liquids and that works effectively in ground cutting is obtained. Although it can be configured, if the full length of the injection nozzle is insufficient or damaged, the ultrahigh pressure jet fluid is broken as shown in FIG. 6B, and an effective ultrahigh pressure jet fluid cannot be configured.
[0008]
Since the nozzle outlet diameter D is about 2 mm, the high-quality injection nozzle N has a total length w as long as about 30 to 40 mm. However, the conventional monitor device has the injection nozzle mounted on the center line of the injection pipe. When the injection pipe has a small diameter, only a simple injection nozzle with a shorter overall length than the high-quality injection nozzle N can be used, expanding the formation range of the solidified body (the ground improvement range) and the creation time (the ground improvement time) ) Has a problem that it is difficult to shorten the construction period.
[0009]
Therefore, the present invention provides a ground improvement work that enables easy use of a good quality injection nozzle N even when the injection pipe has a small diameter, thereby shortening the construction period. To the law The main purpose is to provide a monitoring device to be used.
[0010]
[Means for Solving the Problems]
Ground improvement method of the present invention that achieves the above object Used for monitoring Is A monitoring device used in a ground improvement method including a process of cutting the ground with an ultra-high pressure jet fluid, Two injection nozzles for injecting ultra-high pressure liquid in the opposite direction are provided in the injection pipe, and the two injection nozzles are viewed from the center of the injection pipe when the axis of each injection nozzle is viewed in a direction parallel to the axis of the injection pipe. Attach to the pipe side of the injection pipe so that it does not overlap the line A partition that partitions the ultra-high pressure liquid supply conduit of the injection pipe in the circumferential direction by the same number as the number of injection nozzles is provided, and each partition pipe partitioned by the partition is communicated with the inlet of the injection nozzle, so that the tip of the injection pipe is Two nozzle mounting blocks projecting into the respective partition pipes are integrally provided on the peripheral side wall, and these two nozzle mounting blocks are projected into the respective partition pipes from the opposite directions along the partition walls. The nozzle mounting block is provided with an inclined bulging portion that increases the amount of bulging as it goes to the tip of the partition pipe, and each partition pipe is formed so as to become gradually narrower as it goes to the tip. Each injection nozzle is arranged so that the inlet side end of the injection nozzle is located at the tip of each nozzle mounting block that protrudes most in the partition line (Invention of Claim 1).
[0011]
[0012]
[0013]
In the case of the monitoring device used for the ground improvement method by the single pipe type super high pressure injection method or the double pipe type high pressure injection method described above, the drilling water is introduced from the upstream side of the injection nozzle to the downstream side of the injection nozzle. A funnel-shaped receiving member for receiving a spherical water stop plug that closes the inlet of the inner pipe is provided at the center of the injection pipe with an inner pipe that supplies the drilled water jet at the center of the jet. Provided in the pipe, the inlet of the inner pipe is opened at the center of the receiving member, and a number of holes through which the drilling water and ultra-high pressure liquid pass are provided on the peripheral receiving surface of the inlet. 2 Invention described in 1.).
[0014]
[Operation and effect of the invention]
[0015]
Claim 1 In the described invention, since the injection nozzle is attached to the side of the pipe while avoiding the center line of the injection pipe, even when the injection pipe has a small diameter, a good quality injection nozzle can be used, and two are used. It is possible to cut the ground simultaneously with two ultrahigh pressure jet fluids that work effectively for cutting the ground, so the construction period can be shortened easily.
[0016]
Further, in the single injection nozzle, the jet reaction force of the ultrahigh pressure liquid causes blurring particularly at the tip portion of the injection pipe, but since the ultrahigh pressure liquid is jetted in the opposite direction from the two jet nozzles, each injection nozzle Therefore, it is possible to cancel out the mutual injection reaction force and to prevent the jet tube from shaking. In order to prevent shaking of the injection pipe, the two injection nozzles are preferably mounted at equal intervals on the side of the pipe of the injection pipe, and one injection nozzle is 180 ° around the tube axis of the injection pipe. When rotated, the tube axis of the injection tube core More preferably, each injection nozzle is attached at a position overlapping with another injection nozzle when viewed in a direction parallel to the line, that is, a point-symmetrical position.
[0017]
In the case of a monitor device in which two injection nozzles are provided in an injection pipe, the amount of super-high pressure liquid discharged is larger than in the case of providing a single injection nozzle, and turbulence tends to occur as the injection pipe becomes smaller in diameter. But The fountain Since the partition for dividing the super-high pressure liquid supply passage of the injection tube into the same number (two) as the number of injection nozzles is provided, and the entrance of one injection nozzle communicates with one partition passage, the discharge of super-high pressure liquid Even if the amount increases, turbulence can be prevented.
[0018]
Claim 2 In the invention described in the above, since the drilling water injection port provided downstream of the injection nozzle is closed upstream of the injection nozzle, even when a high-quality injection nozzle is attached to a small-diameter injection pipe, By inserting a spherical water stopcock such as a steel ball into the injection pipe, the drilled water injection port can be closed. As a result, the ground improvement method by the single pipe type super high pressure injection method or the double pipe type high pressure injection method can be performed in the same process as the conventional one.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a monitoring apparatus according to the present invention, and FIG. 2 is a transverse sectional view of the monitoring apparatus. This monitoring apparatus 1 is grounded by a ground improvement method using a single pipe type super high pressure injection method such as a CCP method. It is attached to the tip of the injection tube 2 used when creating a cylindrical solid body, and the injection tube 2 is a fixed length steel tube (single tube) having an outer diameter of about 55 mm. Are connected in a straight line from the monitor device 1 at the front end in one direction, two steps,..., N steps, and as shown in FIG. 3, the end of the injection pipe 2 opposite to the monitor device 1 It is constructed by attaching a swivel 4 for a single pipe to the end of the final stage injection pipe material 3, and high-pressure drilling water with a pressure of about 3 MPa from an ultra-high pressure pump (not shown) and ground cutting with a pressure of about 20-40 MPa. Cement-based ultra-high pressure hardener liquid (cement mill) ) And are adapted to inject from the monitor apparatus 1 of the injection to tip alternatively injection tube 2 from a single injection port 5 provided on the swivel 4.
[0020]
In addition, the hook part 6 for suspending the injection pipe 2 with a crane etc. in the end part of the swivel 4 is provided integrally.
[0021]
As shown in FIGS. 1 and 2, the monitoring device 1 includes two injection nozzles N1 and N2 having a long overall length that satisfy the conditions of the high-quality injection nozzle N shown in FIG. 5, and a monitor tube provided with the injection nozzles N1 and N2. 7, the monitor tube 7 has the same outer diameter as the spray tube 3... And is shorter than the spray tube 3. A connecting means 8 for connecting the end of the injection tube 3 (first-stage injection tube 3) in a straight line is provided at one end of the monitor tube 7, and the tip of the injection tube 3 is constituted by the monitor tube 7. At the same time, the end of the monitor tube 7 opposite to the connection end with the injection tube 3 is attached to the end of the metal crown 9 which is a short cylindrical drilling device having the same outer diameter as the injection tube 3 and the monitor tube 7. The connecting means 10 for connecting the two in a straight line is provided, and the metal crown 9 is attached to the tip of the monitor tube 7, that is, the most distal end of the injection tube 2.
[0022]
In this embodiment, a male screw for screwing a female screw 8a formed on the inner peripheral surface of the end portion of the injection tube material 3 is shown as a connecting means 8 for the injection tube material 3 provided at one end portion of the monitor tube 7. Although the configuration in which the ends of the tube material 3 are directly connected by screwing is shown, the screws in this case may be male or female, and the ends of the monitor tube 7 and the injection tube material 3 may be connected using a socket-type pipe joint or the like. Is indirectly connected, the connection means 8 has a form corresponding to the connection end of the pipe joint. Further, as a connection means 10 for the metal crown 9 provided at the distal end portion of the monitor tube 7, a female screw for screwing a male screw 10 a formed on the outer peripheral surface of the attachment end portion of the metal crown 9 is shown. In this case, the screws are directly connected to each other, but the screws in this case may be male or female, and the ends of the monitor tube 7 and the metal crown 9 are indirectly connected to each other using a socket-type pipe joint or the like. In the case of connection, the connection means 10 has a form corresponding to the connection end of the pipe joint.
[0023]
Further, the monitor tube 7 is provided with a tube bottom 11 on the downstream side of the injection nozzles N1 and N2, and a drilled water injection port 12 is formed at the center of the tube bottom 11. The tip of the inner tube 13 provided along the tube axis direction is fitted to the center of the monitor tube 7 in the hole water injection port 12, and high-pressure hole water is introduced from the upstream side of the injection nozzles N1 and N2. An inner pipe 14 that is supplied to the drilled water jet 12 on the downstream side of the jet nozzles N1 and N2 is provided in the center of the monitor pipe 7 along the pipe axis direction, and a pipe bottom is provided around the inner pipe 14. 11 is provided with an outer conduit 15 which is a dead end at 11 and has its tip closed.
[0024]
The tube bottom 11 is provided in a raised state at a position inward of the tube axis center of the predetermined dimension from the tip of the monitor tube 7, and the connection to the metal crown 9 is provided at the tip of the monitor tube 7 ahead of the tube bottom 11. Means 10 are provided.
[0025]
Further, a steel ball 16 which is a spherical water stopcock having a diameter smaller than the inner diameter of the injection pipe 2 and larger than the inner diameter of the inner pipe 13 is provided, and is opposite to the tip of the inner pipe 13 fitted to the drilled water injection port 12. The inlet 14a is closed by fitting a part of the steel ball 16 into the end opening of the inner pipe 14, that is, the inlet 14a of the inner conduit 14. This steel ball 16 is inserted into the injection tube 2 from the end opening of the injection tube 2 with the swivel 4 removed, and is inserted into the monitor tube 7 at the tip, and a funnel-shaped receiving member for receiving the steel ball 16 17 is provided in the monitor pipe 7 on the upstream side of the injection nozzles N1 and N2 in such a posture that the diameter of the pipe 17 decreases toward the inner side in the axial direction of the monitor pipe 7, and the flow of the inner pipe 14 is provided at the center of the receiving member 17. The inlet 14a is formed as an opening, and a large number of holes 18 are provided on the peripheral receiving surface 17a of the inlet 14a to allow the ultrahigh-pressure curable material liquid to flow into the outer pipe 15. Further, the monitor pipe 7 is provided with a partition wall that divides the outer pipe line 15 in the circumferential direction into the same number (two) as the number of injection nozzles. Since the monitor pipe 7 is provided with two injection nozzles N1 and N2, two partition walls are provided. 19a and 19b are stretched at 180 ° symmetrical positions in the outer pipe line 15 of the monitor tube 7 and provided on one central line X of the monitor tube 7 when viewed in a direction parallel to the tube axis of the monitor tube 7. The outer partition 15 is divided into two equal parts in the circumferential direction by the two partition walls 19a, 19b, and the inlet of one injection nozzle N1 is communicated with the first semi-outer conduit 15a that is one partition passage, The inlet of the other injection nozzle N2 is connected to the second semi-outer pipe 15b which is the other partition passage.
[0026]
In order to provide the monitor pipe 7 with two injection nozzles N1 and N2 that satisfy the conditions of the high-quality injection nozzle N shown in FIG. 5, the two injection nozzles N1 and N2 are provided with shafts of the injection nozzles N1 and N2. In the tube side portion of the monitor tube 7, the cores X <b> 1 and X <b> 2 are not overlapped with the one center line X when viewed in a direction parallel to the tube axis of the monitor tube 7. , Attached to the peripheral side wall of the monitor tube 7 in total, two nozzle mounting blocks 20a and 20b are integrally provided on the peripheral side wall of the monitor tube 7 so as to project one by one into each of the semi-outer pipes 15a and 15b. The two nozzle mounting blocks 20a and 20b project into the semi-outer pipes 15a and 15b from the opposite direction along the partition walls 19a and 19b, and the nozzle mounting blocks 20a and 20b are provided with the semi-outer pipes 15a and 15b. Inclined projecting portions 21a and 21b that increase the amount of projecting toward the tip portion of 15b are provided, and each nozzle mounting block 20a and 20b is projected most in the semi-outer conduits 15a and 15b at the tip portion. The semi-outer pipes 15a and 15b are formed so as to be gradually narrowed toward the tip. Also, nozzle housing recesses 22a and 22b are provided at the tip portions of the nozzle mounting blocks 20a and 20b that protrude most in the semi-outer pipe lines 15a and 15b, and the tip portions of the nozzle mounting blocks 20a and 20b are connected to the monitor tube. The nozzle receiving recesses 22a and 22b are formed in the opposite direction along the partition walls 19a and 19b from the outer peripheral surface of the nozzle 7 so as to form the nozzle receiving recesses 22a and 22b. Screw holes 24a and 24b are formed in the bottom surfaces 23a and 23b of the nozzle housing recesses 22a and 22b in the direction orthogonal to the center line X so as to penetrate the tip ends of the semi-outer pipes 15a and 15b. By screwing the male screw portions 25a, 25b at the inlet side end portions into the screw holes 24a, 24b, the two injection nozzles N1, N2 are connected to the nozzle receiving recesses 22a, 22 respectively. Each of which is accommodated within the outer diameter of the monitor tube 7 and connected to the tip of the semi-outer pipes 15a and 15b, and viewed in a direction parallel to the tube axis of the monitor tube 7. Attached to the side of the tube avoiding the center line of the monitor tube 7 where the axis X1, X2 of the injection nozzle N1, N2 does not overlap with the one center line X in the direction perpendicular to the tube axis. The ultra-high pressure curable material liquid is sprayed from the two spray nozzles N1, N2 to the outside of the monitor tube 7 in the direction opposite to the direction perpendicular to the tube axis, and sprayed from the two spray nozzles N1, N2. The ground around the monitor tube 7 is cut with two ultrahigh-pressure jet fluids effective for cutting the ground as shown in FIG.
[0027]
Each of the spray nozzles N1 and N2 has a tube axis of the monitor tube 7 when one spray nozzle N1 is rotated 180 ° about the tube axis of the monitor tube 7. core It is attached at a position overlapping with another injection nozzle N2 when viewed in a direction parallel to the line, that is, a point-symmetrical position.
[0028]
In the figure, reference numerals 26a and 26b denote seal members for closing gaps between the male screw portions 25a and 25b at the inlet side end portions of the injection nozzles N1 and N2 and the screw holes 24a and 24b on the monitor tube 7 side into which the screw portions are screwed. In this embodiment, the two injection nozzles N1 and N2 are attached to the monitor tube 7 on a plane perpendicular to the tube axis, but the two injection nozzles N1 and N2 are arranged in the axial direction of the monitor tube 7. You may attach with a predetermined space | interval (with a level | step difference).
[0029]
Next, FIGS. 4 (a) to 4 (e) relate to the present invention by a single tube type ultrahigh pressure injection method such as a CCP method using an injection tube 2 (single tube) having the monitor device 1 attached to the tip. Using a monitoring device It is explanatory drawing which shows the construction procedure which produces | generates the cylindrical solid body P vertically in the ground by the ground improvement construction method, The figure (a) is an installation process, The figure (b) is a drilling process, The figure (C) shows an injection test process, (d) shows a cutting / creation process, (e) shows a drawing / cleaning process, and each process will be described below.
[0030]
a. Installation process
The boring machine M is moved to a predetermined construction position, installed, the monitor pipe 7 of the monitor device 2 is attached to the lower end of one injection pipe member 3, the swivel 4 is attached to the upper end, and the metal is attached to the lower end of the monitor pipe 7. The shortest injection pipe 2 to which the crown 9 is attached stands vertically on the ground, and the inlet 5 of the swivel 4 is connected to the outlet of the ultrahigh pressure pump.
[0031]
b. Drilling process
In the installation process, high-pressure drilling water with a pressure of about 3 MPa from the ultrahigh-pressure pump is injected from the injection port 5 of the swivel 4 attached to the upper end into the shortest injection pipe 2 which is vertically set up at a predetermined construction position by the boring machine M. Then, the high-pressure drilling water is jetted downward from the lower end drilling water jet port 12 of the jet pipe 2 in the direction of the pipe axis, and the boring machine M causes the jet pipe 2 around the pipe axis at a speed according to the geological conditions. Drilling is started by lowering at a speed according to the geological condition while rotating or reversing. Thereafter, according to the drilling depth, the injection pipe material 3 is connected to two stages, three stages,..., N stages, drilling is performed while extending the injection pipe 2 into the ground, and drilling is performed to the planned depth.
[0032]
Here, the high-pressure drilling water injected from the upper end into the injection pipe 2 flows into the monitor pipe 1 constituting the lower end of the injection pipe 2 from the upper end opening. It flows into the inner pipe 14 from an inlet 14a formed upstream of N1 and N2, passes through the center of the monitor pipe 7, and is formed in the pipe bottom 11 downstream of the injection nozzles N1 and N2. It is sprayed from the drilled water injection port 12 and assists drilling by the metal crown 9. Further, the high-pressure drilling water that has flowed into the monitor pipe 1 passes through a number of holes 18 provided in the receiving surface 17 a of the receiving member 17 and also enters the outer pipe line 15 around the inner pipe line 14. It flows in and is also injected from each of the injection nozzles N1 and N2 to assist drilling, but the pressure is low and there is no ground cutting ability.
[0033]
c. Injection test process
After drilling, the swivel 4 is removed from the upper end of the injection pipe 2, and a steel ball 16 is inserted into the injection pipe 2 from its end opening, and the inside of the injection pipe 2 is dropped to the downstream side of the injection nozzles N1, N2. The state where the drilled water injection port 12 formed in the center of the tube bottom 11 is closed, the swivel 4 is attached to the upper end of the injection tube 2 again, and the injection port 5 of the swivel 4 is connected to the discharge port of the ultrahigh pressure pump Then, the jet pipe 2 is pulled up at a speed set on a trial basis while rotating or reversing at a speed set on a trial basis. At this time, the drilling water is switched to the curing material liquid, and the discharge pressure of the ultrahigh pressure pump is increased to about 20 to 40 MPa, and the ultrahigh pressure curing material liquid from the ultrahigh pressure pump is injected from the inlet 5 of the swivel 4 to the injection pipe. 2, and an ultra-high pressure curable material liquid is sprayed from each of the spray nozzles N <b> 1 and N <b> 2 at the lower end of the spray pipe 2 to perform a spray test. If this injection test is successful, the process proceeds to the creation process.
[0034]
Here, the steel ball 16 thrown into the injection pipe 2 enters the monitor pipe 1 constituting the lower end of the injection pipe 2 from the upper end opening, and enters the monitor pipe 7 upstream of the injection nozzles N1 and N2. By being received by the provided funnel-shaped receiving member 17 and partially fitting into the inlet 14a of the inner conduit 14 formed in the center of the receiving member 17, the inlet 14a is closed. The drilled water injection port 12 formed in the center of the tube bottom 11 on the downstream side of the injection nozzles N1 and N2 is closed. As a result, even when high-quality injection nozzles N1 and N2 are attached to the small-diameter injection pipe 2, a spherical water stopcock such as a steel ball 16 is inserted into the injection pipe 2 in the same manner as in the prior art, so that the drilling water injection opening 12 can be blocked.
[0035]
When the inlet 14 a of the inner conduit 14 is blocked by the steel ball 16, the super-high pressure curable material liquid injected from the upper end into the injection pipe 2 is put into the monitor pipe 1 constituting the lower end of the injection pipe 2. It flows in from this upper end opening, passes through many holes 18... Provided in the receiving surface 17 a of the receiving member 17 upstream of the injection nozzles N 1 and N 2 in the monitor pipe 2, and passes through the inner pipe line 14. Without flowing into the outer pipe 15, only into the outer pipe 15 around the inner pipe 14 and injected from the injection nozzles N1 and N2.
[0036]
d. Cutting and creation process
While maintaining the predetermined rotation or reversal speed and pulling speed of the injection pipe 2, the super high pressure curing liquid is continuously injected into the injection pipe 2 from the ultra high pressure pump, and each injection nozzle at the lower end of the injection pipe 2 The ultrahigh-pressure curable material liquid is continuously jetted from N1 and N2, and the ground around the injection pipe 2 is cut with two ultrahigh-pressure jet fluids constituted by the ultrahigh-pressure curable material liquid jetted from the jet nozzles N1 and N2. Together with stirring and kneading, a cylindrical solid body (underground pile) P is formed to the upper limit of the formation area.
[0037]
Here, the injection nozzles 1 and N2 are viewed in a direction parallel to the tube axis of the monitor tube 7, and the axis X1 and X2 of the injection nozzles N1 and N2 do not overlap with the one center line X. As shown in FIG. 5 as an injection nozzle, even the smallest diameter injection pipe 2 of the super-high pressure injection method is attached to the side of the pipe avoiding the center line of the monitor pipe 7 in the direction perpendicular to the pipe axis. N1 and N2 can be used (attached), and two can be used (attached). As a result, the two ultra-high pressure jet fluids formed by the ultra-high pressure hardening material liquid ejected from the ejection nozzles N1 and N2 are the ultra-high pressure jet fluids that work effectively in ground cutting as shown in FIG. Compared to the case of using a simple injection nozzle with a short overall length, the construction range of the consolidated body P (the ground improvement range) is expanded and the construction time (the ground improvement time) is shortened. It can be shortened.
[0038]
In addition, in a single injection nozzle, the injection reaction force of the ultrahigh-pressure curable material liquid causes blurring, particularly at the tip (1 part of the monitor device) of the injection tube 2, but the ultrahigh pressure in the opposite direction from the two injection nozzles N1 and N2. Since the liquid is jetted, the jet reaction forces can be offset by the jet nozzles N1 and N2, and the jet pipe 2 can be prevented from shaking.
[0039]
In addition, in the case of a double pipe or triple pipe type ultra-high pressure injection method, an injection nozzle for compressed air is provided around the outlet of an injection nozzle for injecting an ultra-high pressure liquid that cuts the ground, and an injection for an ultra-high pressure liquid is performed. Even if the outlet of the nozzle protrudes from the outer peripheral surface of the injection pipe (double pipe, triple pipe), the surrounding injection nozzle for compressed air serves as a protective cover for the outlet of the injection nozzle for ultra-high pressure liquid, Although the injection nozzle for ultra high pressure liquid is not damaged at the time of drilling, in the case of the single tube type ultra high pressure injection method, since the injection nozzle for compressed air is not provided, the outlets of the injection nozzles N1 and N2 are provided. If protruding from the outer peripheral surface of the injection pipe 2 (single pipe), there is a risk of damaging the injection nozzles N1 and N2 during drilling. However, the injection nozzles N1 and N2 are accommodated in the nozzle accommodating recesses 22a and 22b for monitoring. Stored within the outer diameter of the tube 7 Al, scratches Tsuruno can prevent the injection nozzle N1, N2 during drilling.
[0040]
Furthermore, when the two injection nozzles N1 and N2 are provided in one injection pipe 2, the discharge amount of the ultra-high pressure curable material liquid is larger than when a single injection nozzle is provided, and the injection pipe 2 has a small diameter. As it becomes, turbulent flow is likely to occur, but the ultra-high pressure curable material liquid injected from the upper end into the injection pipe 2 flows into the monitor pipe 7 constituting the lower end portion of the injection pipe 2 from the upper end opening, In this monitor pipe 2, it passes through many holes 18 ... provided in the receiving surface 17a of the receiving member 17 on the upstream side of the injection nozzles N1, N2, and one outer pipe around the inner pipe 14 The passage 15 flows into two semi-outer pipes 15a and 15b formed by being divided into two equal parts in the circumferential direction by the two partition walls 19a and 19b, and with respect to the one half-outer pipe 15a and 15b. The entrance of one injection nozzle N1, N2 is connected, Since the super high pressure curable material liquid is ejected from the injection nozzles N1, N2, the flow of the super high pressure curable material liquid is stabilized in one direction in each of the semi-outer pipes 15a, 15b, and the discharge amount of the super high pressure curable material liquid is large. Thus, turbulent flow can be prevented even with the small diameter injection pipe 2.
[0041]
e. Drawing / cleaning process
The injection tube 2 is pulled out to the ground, the monitor tube 7 is removed from the first-stage injection tube 2a of the injection tube 2, the steel ball 16 is taken out, and the monitor tube 7 is connected to the first-stage injection tube 2a of the injection tube 2 again. In this state, the ultra-high pressure curable material liquid is switched to fresh water, the discharge pressure of the ultra-high pressure pump is lowered to a predetermined pressure, and fresh water from this ultra-high pressure pump is injected into the injection pipe 2 from the inlet 5 of the swivel 4 and injected. Clean water is jetted from the jet nozzles N1 and N2 and the drilled water jet port 12 at the lower end of the pipe 2, and the residual hardening material liquid in the jet pipe 2 and the jet nozzles N1 and N2 is discharged and washed by this jet. .
[0042]
After that, the boring machine M is moved and installed at the next formation point, and a cylindrical solid body P is formed in the ground by the same procedure.
[0043]
In this embodiment, two injection nozzles N1 and N2 for injecting an ultra-high pressure curable material liquid, which is an ultra-high pressure liquid, in the reverse direction are provided in the monitor tube 7 constituting the tip of the injection tube 2, and two injection nozzles are provided. The tubes of the monitor tube 7 are arranged such that N1 and N2 are not overlapped with the center line of the monitor tube 7 when the axial centers X1 and X2 of the injection nozzles N1 and N2 are viewed in a direction parallel to the tube axis of the monitor tube 7. A CCP method which is attached to the side and cuts the ground with two ultra-high pressure jet fluids composed of the ultra-high pressure hardened material liquid sprayed from the spray nozzles N1 and N2 to form a cylindrical solid body P in the ground The ground improvement method by the single pipe type ultra-high pressure injection method such as the above, and the monitoring device 1 used therefor, that is, the two injection nozzles N1, N2 for injecting the ultra-high pressure hardening material liquid which is an ultra-high pressure liquid in the reverse direction Provided on the monitor tube 7 constituting the tip of the Monitor nozzles N1 and N2 so that the axis X1 and X2 of each of the spray nozzles N1 and N2 are not parallel to the center line of the monitor tube 7 when viewed in a direction parallel to the tube axis of the monitor tube 7. 7 shows the monitor device 1 attached to the pipe side portion, but when any one of the injection nozzles N1 and N2 shown in this embodiment is omitted and the partition walls 19a and 19b are also omitted. The super high pressure curable material liquid is sprayed in one direction from one spray nozzle N1, and the ground is cut by one super high pressure jet fluid that is composed of the super high pressure curable material liquid sprayed from the spray nozzle N1. Columnar consolidated body P is formed. Further, the two injection nozzles N1 and N2 shown in the present embodiment are additionally provided with one injection nozzle N3 having a long overall length that satisfies the conditions of the high-quality injection nozzle N shown in FIG. The two injection nozzles N1, N2, and N3 are arranged at 120 ° intervals, and the axis X1, X2, and X3 of each injection nozzle N1, N2, and N3 are viewed in a direction parallel to the tube axis of the monitor pipe 7, and When it is attached to the tube side of the monitor tube 7 so as not to overlap with the center line, the outer conduit 15 is also divided into three equal parts in the circumferential direction by three partition walls 19a, 19b, 19c, or Two injection nozzles N3 and N4 having a long overall length that satisfy the conditions of the high-quality injection nozzle N shown in FIG. 4 injection nozzles N1, N2, N , N4 at 90 ° intervals, the axis X1, X2, X3, X4 of each injection nozzle N1, N2, N3 overlaps with the center line of the monitor tube 7 when viewed in a direction parallel to the tube axis of the monitor tube 7. If it is attached to the pipe side of the monitor pipe 7 so that the outer pipe 15 is divided into four equal parts in the circumferential direction by the four partition walls 19a, 19b, 19c. An ultra-high pressure curing material liquid is sprayed in a different direction from the nozzle (N1, N2, N3) or (N1, N2, N3, N4), and the spray nozzle (N1, N2, N3) or (N1, N2, N3, N4) The ground is cut with three or four ultrahigh-pressure jet fluids composed of the ultrahigh-pressure hardener liquid jetted from above to form a cylindrical solid body P in the ground.
[0044]
As is apparent from the above, the present embodiment is an invention of a superordinate concept in which the number of injection nozzles of the present invention is not limited to two but limited to a plurality of two or more, that is, “the ground is cut with an ultrahigh pressure jet fluid. In the ground improvement method including the steps, a plurality of injection nozzles for injecting ultra-high pressure liquid in different directions are provided in the injection pipe, and the axis of each injection nozzle is parallel to the tube axis line of the injection pipe. It is attached to the pipe side of the injection pipe so that it does not overlap with the center line of the injection pipe when viewed in the direction, and the ground is cut with a plurality of ultrahigh pressure jet fluids composed of the ultrahigh pressure liquid injected from the injection nozzle. "A ground improvement method characterized by the above" and "A plurality of injection nozzles for injecting ultra-high pressure liquid in different directions are provided in the injection pipe, and the axis of each injection nozzle is connected to the tube axis line of the injection pipe. The center line of the injection tube when viewed in parallel The monitoring device used in the ground improvement method attached to the pipe side portion of the injection pipe so that it does not overlap "can be utilized as an embodiment that uniquely finds out, and the number of the injection nozzles of the present invention is not limited. The invention further higher than the concept, that is, “in the ground improvement method including the step of cutting the ground with an ultra-high pressure jet fluid, an injection nozzle for injecting an ultra-high pressure liquid is provided in the injection pipe, and the injection nozzle is arranged on the axis of the injection nozzle. Is attached to the side of the tube of the injection tube so that it does not overlap with the center line of the injection tube when viewed in a direction parallel to the tube axis of the injection tube, and the ultra-high pressure jet formed by the ultra-high pressure liquid injected from the injection nozzle "A ground improvement method characterized by cutting the ground with a body." And "An injection nozzle for injecting an ultra-high pressure liquid is provided in the injection pipe, and the injection nozzle is the tube axis of the injection pipe. The monitoring device used in the ground improvement method attached to the side of the pipe of the injection pipe so that it does not overlap with the center line of the injection pipe when viewed in a direction parallel to the line. " It goes without saying that the invention of these superordinate concepts can achieve the same object as the present invention.
[0045]
Ground improvement work by single pipe super high pressure injection method such as CCP method as mentioned above To the law Monitor device to be used 1 The present invention and the invention of its superordinate concept have been described with reference to examples, but the JSG method using a jet pipe (double pipe) whose outer diameter is about 60 mm thicker than the jet pipe 2 (single pipe) of this example Double pipe type super high pressure injection method such as CJG method using a jet pipe (triple pipe) whose outer diameter is about 90 mm thicker than this example, triple pipe type super high pressure injection method such as RJP method, and similar to these methods If it is a ground improvement method including a process of cutting the ground with an ultra-high pressure jet fluid, including other construction methods, ultra-high pressure liquids such as ultra-high pressure water and ultra-high pressure hardening material liquid are used to form the ultra-high pressure jet fluid. The invention of the present invention and the superordinate concept thereof can be applied to the spray nozzle for spraying.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a monitor device according to the present invention.
FIG. 2 is a cross-sectional view of the monitor device
Fig. 3 External view of the swivel part of the injection pipe
FIG. 4 relates to the present invention. Using a monitoring device Explanatory drawing showing the construction procedure of the ground improvement method
FIG. 5 is an explanatory diagram of a high quality injection nozzle.
[Fig. 6] Explanatory drawing of super high pressure jet fluid
[Explanation of symbols]
1 Monitor device
2 Injection pipe
4 Swivel
7 Monitor tube (the tip of the injection tube)
11 Tube bottom
12 Drilling water jet
14 Inner pipeline
14a Inlet
15 Outer pipeline
15a, 15b Semi-outer pipe line
16 Steel ball (water stopcock)
17 Receiving member
17a Reception surface
18 holes
19a, 19b Bulkhead
20a, 20b Nozzle mounting block
22a, 22b Nozzle housing recess
N1, N2 injection nozzle
M Boring machine
P consolidated body

Claims

A monitoring device used in a ground improvement method including a step of cutting the ground with an ultra-high pressure jet fluid, wherein two injection nozzles for injecting ultra-high pressure liquid in opposite directions are provided in an injection pipe, and two injection nozzles are provided, as the axis of the injection nozzle does not overlap with the center line of the injection tube when seen in the direction parallel to the tube axis core of the injection tube, attached to the tube side of the injection tube, the ultra-high pressure liquid supply line of the injection tube A partition wall is provided in the circumferential direction that is divided into the same number as the number of injection nozzles, and each partition pipe line partitioned by the partition wall is communicated with the inlet of the injection nozzle, and the peripheral side wall at the tip of the injection pipe is placed in each partition pipe line. Two nozzle mounting blocks each projecting are provided integrally, and the two nozzle mounting blocks are projected into the respective partition pipes from the opposite directions along the partition walls, and the partition walls are arranged on the nozzle mounting blocks. Inclined overhangs that increase the amount of overhang as you go to the tip of the road, and form each partition pipe so that it gradually becomes narrower as you go to the end of the road, and the most in each partition pipe A monitor device in which each injection nozzle is arranged so that the inlet side end of the injection nozzle is positioned at the tip of each nozzle mounting block that protrudes .

A spherical shape that closes the inlet of the inner pipe while providing an inner pipe in the center of the jet pipe that feeds drill water from the upstream side of the jet nozzle and supplies it to the drilled water jet of the downstream side of the jet nozzle A funnel-shaped receiving member for receiving the water stop cock is provided in the injection pipe upstream of the injection nozzle, and the inlet of the inner pipe is opened at the center of the receiving member, and the peripheral receiving surface of the inlet is ground. monitoring device according to claim 1 having a plurality of holes for passing hole water or ultra high pressure liquid.