JP2000054365A - Soil improvement work by high pressure injection - Google Patents
Soil improvement work by high pressure injectionInfo
- Publication number
- JP2000054365A JP2000054365A JP10225709A JP22570998A JP2000054365A JP 2000054365 A JP2000054365 A JP 2000054365A JP 10225709 A JP10225709 A JP 10225709A JP 22570998 A JP22570998 A JP 22570998A JP 2000054365 A JP2000054365 A JP 2000054365A
- Authority
- JP
- Japan
- Prior art keywords
- ground
- pressure
- muddy
- injection
- hardening material
- 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
Landscapes
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、予め高圧液により
地盤を切削し、泥状化した領域中にスラリー状の硬化材
を噴射し、この泥状化領域中ので泥状物と前記硬化材を
混合するとともに余剰の泥状物を地上に排出して地盤中
に硬化体を造成する高圧噴射地盤改良工法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of cutting a ground with a high-pressure liquid in advance and injecting a slurry-like hardening material into a muddy region. The present invention relates to a high-pressure injection ground improvement method for mixing hard water and discharging excess mud to the ground to form a hardened body in the ground.
【０００２】[0002]
【従来の技術】従来、高圧噴射地盤改良工法としては、
いわゆる「ＪＳＧ工法」や「コラムジェット工法」が主
流であり現在も多用されている。2. Description of the Related Art Conventionally, as a high-pressure injection ground improvement method,
The so-called “JSG method” and “column jet method” are mainstream and are still frequently used.
【０００３】「ＪＳＧ工法」とは、硬化材を噴射する核
ノズルと核ノズルの周囲を包囲しエアを噴射する包囲ノ
ズルとから構成される高圧噴射ノズルを先端部に設けた
注入管を地中に挿入し、この噴射ノズルからエアを伴っ
た硬化材を高圧噴射する工法である。[0003] The "JSG method" refers to an underground injection pipe provided with a high-pressure injection nozzle comprising a core nozzle for injecting a hardening material, and a surrounding nozzle for surrounding the core nozzle and injecting air. And a high-pressure injection of a hardening material accompanied by air from the injection nozzle.
【０００４】また「コラムジェット工法」とは、注入管
先端部の下段に設けた硬化材噴射ノズルとその上段に設
けた高圧水を噴射する核ノズルとその周囲を包囲しエア
を噴射する包囲ノズルとから構成される高圧水噴射ノズ
ルによって、まず上段の高圧水噴射ノズルからエアを伴
った高圧水を噴射し地盤を切削したのち、下段の硬化材
噴射ノズルから硬化材を噴射する工法である。[0004] The "column jet method" refers to a hardening material injection nozzle provided at a lower portion of a tip end portion of an injection pipe, a nucleus nozzle provided at an upper portion thereof for injecting high-pressure water, and an encircling nozzle for surrounding and injecting air around the nozzle. This is a method in which high pressure water with air is injected from the upper high pressure water injection nozzle to cut the ground, and then the hardening material is injected from the lower hardening material injection nozzle.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、これら
の工法はいずれも地盤中に噴射した硬化材（一般的には
セメント）が切削した泥状物に混じり、泥状物と一緒に
地上に大量に排出されるという問題があった。硬化材混
じりの泥状物は廃棄物としての処理が困難となるだけで
なく、地上に排出される硬化材は無駄となるため、材料
コストも嵩むことになる。However, in each of these methods, the hardening material (generally, cement) injected into the ground mixes with the cut mud, and a large amount of the hard material (generally cement) is put on the ground together with the mud. There was a problem of being discharged. Not only is it difficult to dispose of the mud containing the hardening material as waste, but also the hardening material discharged to the ground is wasted, thus increasing the material cost.
【０００６】さらに、地盤中において、硬化材と泥状物
とが混合された泥状混合物中は、その硬化前のおいて砂
分が沈降してしまい、泥状化領域の下端付近に砂分が滞
積し、結果的に硬化材成分が少なくなり、その部分が未
団結となるという問題もあった。Further, in the muddy mixture in which the hardening material and the muddy material are mixed in the ground, sand is settled before the hardening, and the sandy material is settled near the lower end of the muddy region. Accumulates, and as a result, there is a problem that the amount of the hardening material component is reduced and the portion is not united.
【０００７】また、最近では、前述のような硬化材の排
出を抑制するため、エアを伴う高圧水による切削工程と
硬化材の注入工程を別工程で行う方法も提案されている
（たとえば特開平９−１４３９７５号公報）が、この方
法によっても硬化材の注入過程においては、硬化材が泥
状物に混じり地上に排出されてしまい、硬化材の排出を
止めることは不可能であった。Recently, a method has been proposed in which a cutting step using high-pressure water with air and a step of injecting the hardening material are performed in separate steps in order to suppress the discharge of the hardening material as described above. However, even in this method, in the process of injecting the hardening material, the hardening material is mixed with the muddy material and discharged to the ground, and it is impossible to stop the discharge of the hardening material.
【０００８】本発明は以上の問題点を鑑みてなれたもの
で、硬化材混じりの泥状物を極力地上部に排出せず、し
かも未固結部分の生じない、計画寸法通りの硬化体を造
成することのできる高圧噴射地盤改良工法を提案するこ
とを課題とする。The present invention has been made in view of the above problems, and provides a hardened material having a planned size which does not discharge as much as possible the muddy material mixed with the hardening material to the above-ground portion and does not cause unconsolidated portions. It is an object to propose a high-pressure injection ground improvement method that can be created.
【０００９】[0009]
【課題を解決するための手段】前記課題を解決した本発
明の請求項１記載の発明は、高圧液、またはエアを伴っ
た高圧液を噴射することによって地盤を切削し、所定領
域を泥状化した後、この泥状化領域中に挿入した注入管
を、泥状化領域の下端部から上方に向かって上昇させる
過程で、１５０〜２０００ｍＰａ・ｓの粘度を有するス
ラリー状の硬化材を吐出し、前記泥状化領域の泥状物と
前記硬化材を混合するとともに余剰の泥状物を地上に排
出して地盤中に硬化体を造成することを特徴とする高圧
噴射地盤改良工法である。According to the first aspect of the present invention, which solves the above-mentioned problems, the ground is cut by jetting a high-pressure liquid or a high-pressure liquid accompanied by air, and a predetermined area is made muddy. After that, the injection pipe inserted into the muddy region is raised upward from the lower end of the muddy region, and a slurry-like hardening material having a viscosity of 150 to 2000 mPa · s is discharged. A high-pressure injection ground improvement method comprising mixing the muddy material in the muddy region and the hardening material and discharging excess muddy material to the ground to form a hardened body in the ground. .
【００１０】請求項２記載の発明は、高圧液を噴射する
核ノズルとこの核ノズルの周囲から圧縮エアを噴射する
包囲ノズルとを有する高圧噴射ノズルを先端部に設けた
注入管を地盤中に挿入した後、前記高圧噴射ノズルから
エアを伴った高圧液を側方に高圧噴射し、前記注入管を
回転させながら地盤改良上限位置まで引き上げ、地盤を
切削するとともにエアリフト効果により切削土砂を地上
に排出することによって所定の泥状化領域を形成し、さ
らに前記泥状化領域の下端部まで注入管を挿入した後、
この注入管を順次引き上げながらこの注入管の先端付近
から１５０〜２０００ｍＰａ・ｓの粘度を有するスラリ
ー状の硬化材を噴射し、前記泥状化領域の泥状物と前記
硬化材を混合するとともに余剰の泥状物を地上に排出し
て地盤中に硬化体を造成することを特徴とする高圧噴射
地盤改良工法である。According to a second aspect of the present invention, an injection pipe having a high-pressure injection nozzle having a core nozzle for injecting high-pressure liquid and a surrounding nozzle for injecting compressed air from the periphery of the core nozzle is provided in the ground. After the insertion, high-pressure liquid with air is injected from the high-pressure injection nozzle to the side at high pressure, and the injection pipe is rotated to pull up to the ground improvement upper limit position. After forming a predetermined muddy region by discharging, and further inserting the injection pipe to the lower end of the muddy region,
A slurry-like hardening material having a viscosity of 150 to 2,000 mPa · s is sprayed from the vicinity of the tip of the injection pipe while sequentially pulling up the injection pipe, and the slurry in the muddy region is mixed with the hardening material and excess A high-pressure injection ground improvement method characterized by discharging a muddy material to the ground to form a hardened body in the ground.
【００１１】請求項３記載の発明は、前記高圧液が１０
０〜７５０ｍＰａ・ｓの粘度を有するスラリー状の液体
であることを特徴とする請求項１または２記載の高圧噴
射地盤改良工法である。According to a third aspect of the present invention, the high-pressure liquid is 10
The high-pressure injection ground improvement method according to claim 1 or 2, wherein the method is a slurry-like liquid having a viscosity of 0 to 750 mPa · s.
【００１２】請求項４記載の発明は、前記硬化材の吐出
圧力が、その圧送ポンプの元圧で２０〜２００Ｋｇｆ／
cm2 であることを特徴とする前記請求項１〜３のいずれ
か１項に記載の高圧噴射地盤改良工法である。According to a fourth aspect of the present invention, the discharge pressure of the hardening material is 20 to 200 kgf / at the original pressure of the pressure feed pump.
The high-pressure injection ground improvement method according to any one of claims 1 to 3, wherein the height is cm 2 .
【００１３】なお、本明細書における粘度はいずれもＢ
型回転粘度計による測定値を基準とする。The viscosity in this specification is B
Based on the value measured by a mold rotational viscometer.
【００１４】[0014]
【発明の実施の形態】本発明の主たる特徴の第１は、予
め地盤を泥状化し、その地盤にスラリー状の硬化材を吐
出させて、泥状化領域の泥状物と硬化材とを混合する点
であり、第２は、従来の前述の高圧噴射地盤改良工法に
用いられてきた噴射材はセメントミルクであり、その粘
度はきわめて小さいものであるのに対して、本発明にお
いては、粘度が１５０〜２０００ｍＰａ・ｓというきわ
めて高い粘度を有するスラリー状の硬化材を用いる点で
ある。BEST MODE FOR CARRYING OUT THE INVENTION The first of the main features of the present invention is that the ground is muddy in advance, a slurry-like hardening material is discharged onto the ground, and the muddy material and hardening material in the muddy region are separated. The second point is that the injection material used in the above-mentioned conventional high-pressure injection ground improvement method is cement milk, whose viscosity is extremely small, whereas in the present invention, The point is that a slurry-like hardening material having an extremely high viscosity of 150 to 2000 mPa · s is used.
【００１５】（施工形態）以下本発明に係る施工形態を
図面を参照しながらさらに詳説する。(Construction form) The construction form according to the present invention will be described in more detail with reference to the drawings.
【００１６】（１）削孔工程 本発明で使用する注入管１は、たとえば図５に示す注入
管１が用いられる。すなわち、注入管１は３流路管であ
り、中央に削孔水Ｗおよび硬化材Ｈ用流路２と高圧液Ｌ
用流路３と圧縮エアＡ用流路４の３流路は有し、その先
端部にはウイングビット等の削孔ビット５が取り付けら
れている。(1) Drilling Step As the injection pipe 1 used in the present invention, for example, the injection pipe 1 shown in FIG. 5 is used. That is, the injection pipe 1 is a three-flow pipe, and the drilling water W and the hardening material H flow path 2 and the high-pressure liquid L
There are three flow paths, i.e., a flow path 3 for compressed air and a flow path 4 for compressed air A, and a drill bit 5 such as a wing bit is attached to the tip of the flow path 3.
【００１７】この削孔ビットには、削孔水Ｗを吐出させ
る吐出孔６が形成されている。この上部には、硬化材噴
射ノズル７が設けられている。この硬化材噴射ノズル７
と吐出孔６の流路方向の切替えは、注入管先端に内蔵さ
れた切替バルブ８により行われる。この切替えバルブ８
は、反発スプリング８Ａに基部側に付勢された弁座８Ｂ
とこの弁座８Ｂに向かって投入されるボール８Ｃとによ
り構成され、削孔水Ｗの供給時には、ボール８Ｃは投入
されていないので、供給される削孔水Ｗは、流路２を通
してそのまま吐出孔６から吐出される。硬化材Ｈの供給
に際しては、ボール８Ｃが投入され、その結果、切替え
バルブ８より先端側がボール８Ｃにより封止されるの
で、供給された硬化材Ｈは硬化材噴射ノズル７から噴出
されるようになる。The drilling bit is formed with a discharge hole 6 for discharging drilling water W. Above this, a hardener injection nozzle 7 is provided. This hardener injection nozzle 7
The switching of the flow direction of the discharge hole 6 and the discharge hole 6 is performed by a switching valve 8 built in the tip of the injection pipe. This switching valve 8
Is a valve seat 8B biased toward the base side by a repulsion spring 8A.
And the ball 8C to be thrown toward the valve seat 8B. When the drilling water W is supplied, since the ball 8C is not thrown, the supplied drilling water W is directly discharged through the flow path 2. Discharged from the hole 6. When the hardening material H is supplied, the ball 8C is thrown in, and as a result, the tip side of the switching valve 8 is sealed by the ball 8C, so that the supplied hardening material H is ejected from the hardening material injection nozzle 7. Become.
【００１８】さらに、硬化材噴射ノズル７の上方位置に
は高圧液Ｌ用流路３に連通した高圧液噴射用核ノズル９
Ａと、圧縮エア用流路４に連通し、前記核ノズル９Ａの
周囲を包囲しエアＡを噴射する包囲ノズル９Ｂとから構
成された、エアを伴う高圧液を側方に高圧噴射するため
の高圧噴射ノズル９が上下２ヶ所に相反する方向に噴射
するように設けられている。下部側の高圧噴射ノズル９
は所定角度斜め上向きに、一方、上部側の高圧噴射ノズ
ル９は所定角度斜め下向きに設けられている。Further, a high-pressure liquid injection core nozzle 9 communicating with the high-pressure liquid L flow path 3 is located above the hardening material injection nozzle 7.
A and a surrounding nozzle 9B which communicates with the compressed air flow path 4 and surrounds the core nozzle 9A and injects the air A. A high-pressure injection nozzle 9 is provided so as to inject in two opposite directions in opposite directions. Lower high-pressure injection nozzle 9
Is directed obliquely upward at a predetermined angle, while the upper high-pressure injection nozzle 9 is provided obliquely downward at a predetermined angle.
【００１９】さて、図１に示すように、かかる注入管１
を用い、ボーリングマシン等の削孔装置１０を用い、前
記注入管１先端の吐出孔６から削孔水Ｗを吐出させなが
ら地盤改良予定下限位置に、注入管１の先端部が到達す
るまで地盤を削孔し、この注入管１を所定位置に配置す
る。Now, as shown in FIG.
Using a drilling machine 10 such as a boring machine, while discharging drilling water W from the discharge hole 6 at the tip of the injection pipe 1, the ground is maintained until the tip of the injection pipe 1 reaches the ground improvement planned lower limit position. And the injection pipe 1 is arranged at a predetermined position.
【００２０】（２）一次切削工程 次いで、図２に示すように、地盤改良予定下限位置か
ら、高圧噴射ノズル９，９からエアを伴った高圧液を側
方に高圧噴射させながら、注入管１を地盤改良上限位置
まで回転させながら引き上げることによって地盤を切削
するとともに、圧縮エアの同伴に伴うエアリフト効果に
より切削土砂を地上に排出し、泥状の地盤改良予定領域
を形成する。(2) Primary Cutting Step Next, as shown in FIG. 2, the injection pipe 1 is injected from the high-pressure injection nozzles 9, 9 while the high-pressure liquid with air is injected at high pressure from the ground improvement planned lower limit position to the side. The ground is cut by rotating it up to the ground improvement upper limit position and cutting the ground, and the cut soil is discharged to the ground by the air lift effect accompanying the compressed air to form a muddy ground improvement scheduled area.
【００２１】この際使用する高圧液（切削水）Ｌとして
はこの切削工程で形成した泥状化領域の孔壁保持性およ
び硬化材注入工程時における置換性の点から、増粘剤の
添加された１００〜７５０ｍＰａ・ｓの範囲の粘度を有
するものが好適である。粘度が１００ｍＰａ・ｓより低
いと泥状化領域Ｚの孔壁が崩壊しやすくなり、また７５
０ｍＰａ・ｓより高くなると後工程での硬化材が目標域
に注入されず、上方に逸走して余剰泥状物と一緒に排出
されてしまう傾向が大きい。As the high-pressure liquid (cutting water) L used at this time, a thickener is added from the viewpoint of the hole wall retention of the mud-like region formed in this cutting step and the substitution during the hardening material injection step. Those having a viscosity in the range of 100 to 750 mPa · s are also suitable. When the viscosity is lower than 100 mPa · s, the pore wall of the muddy zone Z is apt to collapse,
When the pressure is higher than 0 mPa · s, the hardening material in the post-process is not injected into the target area, but tends to run upward and be discharged together with the excess mud.
【００２２】この点については後述の実験例においてさ
らに説明する。ここで使用する増粘剤としてはセルロー
ス系、アクリル系、天然高分子系、繊維状鉱物系など種
々のものを使用することができる。This point will be further described in an experimental example described later. As the thickener used here, various types such as a cellulose type, an acrylic type, a natural polymer type, a fibrous mineral type and the like can be used.
【００２３】また、高圧液も噴射圧力は、この高圧液を
圧送する高圧ポンプ１１の元圧で約２００〜７００Ｋgf
／cm2 、一方、圧縮エアの圧力はエアを搬送するコンプ
レッサ１２の元圧で５〜１０Ｋｇｆ／cm2 に設定するの
が好適である。The injection pressure of the high-pressure liquid is about 200 to 700 kgf at the original pressure of the high-pressure pump 11 for pumping the high-pressure liquid.
/ Cm 2, on the other hand, the pressure of the compressed air is preferably set to 5 to 10 kgf / cm 2 as the original pressure of the compressor 12 for conveying the air.
【００２４】地上部に排出された切削液と土砂の混合物
からなる排泥Ｍは、排泥ポンプ装置１３によりピットか
ら脱水装置（図示せず）に送り込んで、土砂分と液状分
とに分離し、分離した液状分はさらに凝集処理等を施
し、切削液や削孔水として再利用するのが望ましい。切
削工程で排出される泥状物には硬化材がほとんど含まれ
ていないため、再利用のための処理がしやすい。一方、
分離した土砂分はダンプトラック等で搬出し適正に処分
する。The sludge M composed of a mixture of cutting fluid and earth and sand discharged to the ground is sent from a pit to a dehydrator (not shown) by a sludge pumping device 13 to be separated into earth and sand and liquid. It is preferable that the separated liquid is subjected to a coagulation treatment or the like and reused as a cutting fluid or drilling water. Since the hard material is hardly contained in the mud discharged in the cutting process, it can be easily processed for reuse. on the other hand,
The separated sediment should be carried out by dump trucks and disposed of properly.
【００２５】（３）注入管再挿入工程 その後、図３に示すように、注入管１を前工程により形
成した泥状化領域Ｚの中に注入管１の先端部が地盤改良
予定下限位置に達するまで建て込む。(3) Injection Pipe Reinsertion Step Thereafter, as shown in FIG. 3, the tip end of the injection pipe 1 is located at the lower limit of the ground improvement scheduled in the muddy region Z formed by the previous step. Build until you reach.
【００２６】泥状化領域Ｚの孔壁が崩壊したり、砂分の
沈降により下端に砂分が滞積している場合には、注入管
１の下降時に高圧液を噴射し、再攪拌し、沈降した砂分
をこの泥状化領域Ｚ中に再浮遊、再分散させる。こうす
ることによって、後工程の硬化材注入がし易くなる。If the pore wall of the muddy zone Z has collapsed or sand has accumulated at the lower end due to sedimentation of the sand, high-pressure liquid is injected when the injection pipe 1 descends, and the liquid is stirred again. The sedimented sand is resuspended and redispersed in the muddy zone Z. This makes it easier to inject the hardening material in a later step.
【００２７】（４）硬化材噴射工程 次に、図４に示すように、注入管１を順次引き上げなが
ら、グラウトポンプ１４により硬化材Ｈを注入管１内に
送り込んで、その先端付近の硬化材噴射ノズル７からス
ラリー状の硬化材Ｈを噴射し、泥状化領域Ｚの泥状物と
硬化材Ｈを混合するとともに余剰の泥状物を地上に排出
して地盤中に硬化体を造成する。(4) Curing Material Injecting Step Next, as shown in FIG. 4, the grout pump 14 feeds the hardening material H into the filling tube 1 while sequentially pulling up the filling tube 1, and the hardening material near the tip thereof. The slurry-like hardening material H is sprayed from the spray nozzle 7 to mix the muddy material in the muddy region Z and the hardening material H, and discharge excess muddy material to the ground to form a hardened material in the ground. .
【００２８】この硬化材としては、注入した硬化材を目
標域に確実に注入させ、上方に逸走するのを防ぐため
に、水／セメント比１００％のセメントスラリーに対
し、増粘剤の添加された１５０〜２０００ｍＰａ・ｓの
範囲の粘度を呈するものを使用し、特に２５０〜５００
ｍＰａ・ｓの粘度を呈するものが好適である。As this hardening material, a thickener was added to a cement slurry having a water / cement ratio of 100% in order to ensure that the injected hardening material was injected into the target area and to prevent upward runaway. Use a material exhibiting a viscosity in the range of 150 to 2000 mPa · s, particularly 250 to 500
Those exhibiting a viscosity of mPa · s are preferred.
【００２９】粘度が１５０ｍＰａ・ｓより低いと、泥状
化領域中に注入した硬化材が 上方に逸走しやすく、硬
化材混じりの泥状物が排出されてしまう。一方、２００
０ｍＰａ・ｓより高くすると、使用する増粘剤の添加量
が過剰となりコスト高になるとともに粘性が高すぎて硬
化材の圧送ラインで閉塞トラブルが発生しやすくなる。
この点については後述の実験結果とともに説明する。ま
た、ここで使用する増粘剤としてはセルロース系、アク
リル系、天然高分子系、繊維状鉱物系など種々のものを
使用することができる。If the viscosity is lower than 150 mPa · s, the hardened material injected into the muddy region easily escapes upward, and the mud mixed with the hardened material is discharged. On the other hand, 200
If it is higher than 0 mPa · s, the amount of the thickener to be used is excessive and the cost is increased, and the viscosity is too high, so that a blocking trouble easily occurs in the pressure feed line of the hardening material.
This will be described together with experimental results described later. In addition, as the thickener used here, various types such as a cellulose type, an acrylic type, a natural polymer type, and a fibrous mineral type can be used.
【００３０】硬化材の吐出圧力は、グラウトポンプ１４
の元圧で２０〜２００Ｋｇｆ／cm2にするのが好適であ
り、切削工程での高圧液の吐出圧力よりかなり低圧力に
設定される。The discharge pressure of the hardening material is controlled by the grout pump 14.
The source pressure is preferably 20 to 200 kgf / cm 2 , and is set to a pressure considerably lower than the discharge pressure of the high-pressure liquid in the cutting process.
【００３１】（実験例） ＜実験１：硬化材の排出状況および砂分の沈澱状況に関
する実験＞本実験は、本発明の硬化材注入工程を想定し
た模擬実験であり、硬化材の粘性を変化させた場合にお
ける、余剰泥状物に混入し排出される硬化材の排出状況
の違いを調べたものである。(Experimental Example) <Experiment 1: Experiment on the state of discharge of hardened material and the state of precipitation of sand> This experiment is a simulation experiment assuming the hardening material injection step of the present invention, and changes the viscosity of the hardened material. In this case, the difference in the state of discharge of the hardened material mixed in and discharged from the excess mud is examined.
【００３２】人工的に作成した模擬泥状化領域中に注入
管を挿入し、その先端から異なる粘性を呈する硬化材を
側方に吐出（吐出量１０リットル／分）しながら注入管
を１分あたり２００ｍｍピッチで順次引き上げることに
よって、硬化材を前記領域中に注入し、その際排出され
る余剰泥状物の各ステップ毎のＰＨ値および注入した硬
化材中における砂分の沈澱厚さを測定し、その結果を表
１に示した。An injection tube is inserted into the artificially formed simulated muddy region, and the injection tube is discharged for 1 minute while discharging a hardening material having a different viscosity to the side (discharge amount 10 liter / min) from the tip. The hardening material is injected into the above-mentioned area by sequentially pulling the hardening material at a pitch of 200 mm, and the PH value of each step of the excess sludge discharged at that time and the thickness of the sediment of the sand in the injected hardening material are measured. The results are shown in Table 1.
【００３３】使用硬化材は水：セメント比が１００％の
セメントスラリーに対し増粘剤を添加量を変化させて加
え、種々の粘性に調整したものである。The hardening material used is prepared by adding a thickener to a cement slurry having a water: cement ratio of 100% by changing the amount of addition to adjust the viscosity to various values.
【００３４】またこの模擬泥状物領域は、エアを伴った
高圧水を噴射し砂質土地盤を切削した際に形成される泥
状化領域を想定したものであり、砂１重量部と水１重量
部とを混合した泥状物（比重約１．３５）を直径５００
ｍｍ、高さ１２００ｍｍの透明なアクリル製の円筒管に
充填し作成したものである。増粘剤としては、セルロー
ス系増粘剤（商品ＭＪ−２：日東化学社製）と繊維状粘
土鉱物系増粘剤（「アタパルジャイト」：ユニオン化成
社製）の２種類を使用した。The simulated muddy area is assumed to be a muddy area formed when high-pressure water with air is injected to cut sandy ground, and 1 part by weight of sand and water 1 part by weight and a slurry (specific gravity of about 1.35) is mixed with a powder having a diameter of 500.
It was prepared by filling a transparent acrylic cylindrical tube having a height of 1200 mm and a height of 1200 mm. As the thickener, two types of a cellulose-based thickener (MJ-2: manufactured by Nitto Kagaku) and a fibrous clay mineral-based thickener ("Attapulgite": manufactured by Union Kasei Co., Ltd.) were used.
【００３５】なお、表１に示す粘度はＢ型粘度計での計
測値である。また泥状物のＰＨ値は、排出される泥状物
に対する硬化材分の混入状況を確認するためのものであ
り、ＰＨ値１１以上になるとかなりのセメント分が含ま
れていると推測される。さらに沈澱の厚さは、硬化材の
注入完了後１５分経過した時点での前記円筒管下部に沈
降した砂分の厚さを計測したものである。The viscosities shown in Table 1 are values measured with a B-type viscometer. Further, the PH value of the muddy material is for confirming the mixing state of the hardened material in the discharged muddy material, and it is estimated that when the PH value is 11 or more, a considerable amount of cement is contained. . Further, the thickness of the sediment is obtained by measuring the thickness of the sand that has settled at the lower part of the cylindrical tube at a point of time when 15 minutes have passed after the completion of the injection of the hardening material.
【００３６】[0036]
【表１】 [Table 1]
【００３７】表１の結果から、セルロース系、繊維状粘
土鉱物系どちらの増粘剤においても粘度を１５０ｍＰａ
・ｓ以上にすれば、排泥水のＰＨ値１１以下、砂分の沈
澱厚さ約１０ｃｍ前後となり、ほぼ良好な結果が得ら
れ、さらに粘度を２５０ｍＰａ・ｓ以上にすれば、ＰＨ
値１０以下、砂分の沈澱厚さ１０ｃｍ以下となり、さら
に良好な結果が得られることが分かる。From the results shown in Table 1, it was found that the viscosity of both the cellulosic and fibrous clay mineral thickeners was 150 mPa.
When the viscosity is 250 mPa · s or more, the PH value is about 11 cm or less, and the sediment thickness is about 10 cm.
The value is 10 or less and the sediment thickness of the sand is 10 cm or less, and it can be seen that even better results can be obtained.
【００３８】＜実験２：孔壁保持性実験＞本実験は、高
圧液（切削水）により地盤を切削した際に形成される泥
状化領域を想定した模擬実験であり、使用する切削水の
粘性を変化させた際の、泥状化領域の孔壁安定性の違い
調べたものである。<Experiment 2: Hole Wall Retention Experiment> This experiment is a simulation experiment assuming a muddy region formed when the ground is cut by high-pressure liquid (cutting water). This is a study of the difference in pore wall stability in the muddy region when the viscosity is changed.
【００３９】まず縦３５０ｍｍ×横５５０ｍｍ×高さ４
００ｍｍの容器に砂を敷き詰め て模擬地盤（相対密度
３０％、密度１．６ｇ／ｃｍ３，飽和度１００％）を作
り、この模擬地盤に予め建て込んでおいた直径５０ｍｍ
の中空パイプ内に種々の粘度を有する模擬切削水を充填
したのち、パイプを地盤から引き抜くことによって模擬
泥状化領域を形成し、次いでこの模擬泥状化領域にセメ
ントミルクを充填し、その結果形成される硬化体の形状
から孔壁保持性を確認するという方法で、切削水の粘性
を変化させた際の孔壁保持性の違いを調べたものであ
る。その結果を表２に示した。First, height 350 mm × width 550 mm × height 4
A simulated ground (relative density 30%, density 1.6g / cm3, saturation 100%) is made by laying sand in a 00mm container, and a diameter of 50mm previously laid on the simulated ground.
After filling the simulated cutting water having various viscosities into the hollow pipe, a simulated muddy region is formed by extracting the pipe from the ground, and then the simulated mudified region is filled with cement milk. In this method, the difference in hole wall retention when the viscosity of cutting water was changed was determined by checking the hole wall retention from the shape of the formed hardened body. The results are shown in Table 2.
【００４０】この疑似切削水は、清水（Ｗ）に添加量を
変えて増粘剤を加え、種々の粘性に調整したものであ
る。増粘剤とては、ポリアニオン化セルロース系増粘剤
（商品名「ＤＫ−ハイポリマー」：第一工業製薬社製）
とセルロース系増粘剤（商品名「ＭＪ−２」：日東化学
工業社製）の２を使用した。This simulated cutting water is prepared by adding a thickening agent to fresh water (W) by changing the amount of addition, and adjusting the viscosity to various viscosities. As the thickener, a polyanionized cellulose-based thickener (trade name “DK-High Polymer”: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
And cellulose-based thickener (trade name “MJ-2”: manufactured by Nitto Chemical Industry Co., Ltd.).
【００４１】[0041]
【表２】 [Table 2]
【００４２】実験２の結果から増粘剤の種類に関係な
く、疑似切削水の粘度を１００ｍＰａ・ｓ程度以上にす
ればほぼ孔壁保持が図れることが判る。From the results of Experiment 2, it can be seen that, regardless of the type of the thickener, if the viscosity of the simulated cutting water is about 100 mPa · s or more, the hole wall can be substantially retained.
【００４３】＜実験３：切削水の粘性の違いによる硬化
材の置換性に関する実験＞本実験は、実験１と同様に本
発明の硬化材注入工程を想定した模擬実験であり、硬化
材の粘性を変化させた場合における、余剰泥状物に混入
し排出される硬化材の排出状況の違いを調べたものであ
る。<Experiment 3: Experiment on Replacement of Hardened Material Due to Difference in Viscosity of Cutting Water> This experiment is a simulation experiment assuming the hardening material injection step of the present invention as in Experiment 1, and the viscosity of the hardened material is This is to examine the difference in the state of discharge of the hardened material mixed in and discharged from the surplus mud when changing.
【００４４】粘性の異なる疑似切削水１重量部と砂１重
量部とを混合し、種々の粘性に調整した実験１と同様な
模擬泥状化領域を作成し、その泥状化領域に対し注入管
を挿入し、次いで、セルロース系増粘剤を添加し粘度２
５０ｍＰａ・ｓに調整した硬化材を吐出（吐出量１０リ
ットル／分）しながら、注入管を１分あたり２００ｍｍ
ピッチで順次引き上げることによって硬化材を前記領域
中に注入し、その際排出される泥状物のＰＨ値を各ステ
ップ毎に測定し、硬化材の排出状況を調べた。1 part by weight of pseudo cutting water having different viscosities and 1 part by weight of sand were mixed to prepare a simulated muddy region similar to that in Experiment 1 in which various viscosities were adjusted, and injected into the muddy region. Insert the tube, then add the cellulosic thickener and add
While discharging the curing material adjusted to 50 mPa · s (discharge rate 10 liter / min), the injection pipe was set to 200 mm / min.
The hardening material was injected into the area by sequentially pulling up at a pitch, and the PH value of the mud discharged at that time was measured at each step, and the state of discharge of the hardening material was examined.
【００４５】その結果を表３に示した。Table 3 shows the results.
【００４６】[0046]
【表３】 [Table 3]
【００４７】この結果から、疑似切削水の粘度を７５０
ｍＰａ・ｓ以下にすれば、排泥水のＰＨ値は約１０以下
となり、排泥水に伴う硬化材の排出を防ぐことが可能で
あることが分かる。７５０ｍＰａ・ｓより粘度を高くし
た場合にはＰＨ値は１１以上を示し、目視でも注入管の
周囲からの硬化材の排出が確認された。これは、切削水
の粘度を高くし過ぎると、注入管から吐出した硬化材が
目標域に注入されずに上方に逸走しやすくなるためと推
定される。From the results, it was found that the viscosity of the pseudo cutting water was 750.
When the pressure is set to mPa · s or less, the pH value of the wastewater becomes about 10 or less, and it is understood that the discharge of the hardening material accompanying the wastewater can be prevented. When the viscosity was higher than 750 mPa · s, the PH value was 11 or more, and discharge of the hardened material from the periphery of the injection tube was visually confirmed. This is presumed to be because if the viscosity of the cutting water is too high, the hardened material discharged from the injection pipe tends to escape upward without being injected into the target area.
【００４８】[0048]
【実施例】図１〜図４に示す工程をもって、図５に示す
注入管を用いて砂質地盤を対象に本発明の実験を行っ
た。EXAMPLE An experiment of the present invention was conducted on the sandy ground using the injection pipe shown in FIG. 5 in the steps shown in FIGS.
【００４９】まず、注入管を砂質地盤中に建て込み、注
入管の核ノズルから清水に重量比０．８％のセルロース
系増粘剤（商品名ＭＪ−２：日東化学工業社製）を添加
し、粘度１８０ｍＰａ・ｓに調整した切削水を４００Ｋ
gf／cm2 の圧力で、一方、包囲ノズルから圧縮空気を７
Ｋｇｆ／cm2 の圧力で噴射することよって切削工程を実
施した。First, an injection pipe was built in sandy ground, and a 0.8% by weight cellulose-based thickener (trade name: MJ-2: manufactured by Nitto Chemical Industry Co., Ltd.) was added to fresh water from the core nozzle of the injection pipe. 400 K of cutting water added and adjusted to a viscosity of 180 mPa · s
At a pressure of gf / cm2, compressed air was
The cutting step was performed by jetting at a pressure of Kgf / cm 2 .
【００５０】次いで切削工程で泥状化した地盤の下端ま
で注入管を再度挿入し、注入管を回転させながら硬化材
噴射ノズルから水：セメント比１００％のセメントスラ
リーに重量比０．６％のセルロース系増粘剤（商品名Ｍ
Ｊ−２：日東化学工業社製）を添加し、粘度４００ｍＰ
ａ・ｓに調整した硬化材を５０Ｋｇｆ／cm2 の圧力で吐
出させ、改良上限位置まで注入管を順次引き上げること
によって硬化材注入工程を実施し、硬化体（直径約２，
４００，長さ１０ｍ）の造成を行った。Next, the injection pipe is inserted again to the lower end of the ground which has been made muddy in the cutting step, and while the injection pipe is being rotated, the cement slurry having a water: cement ratio of 100% is added to the cement slurry having a water: cement ratio of 0.6% while rotating the injection pipe. Cellulose thickener (trade name M
J-2: manufactured by Nitto Chemical Industry Co., Ltd.), and the viscosity was 400 mP.
The hardening material adjusted to a · s is discharged at a pressure of 50 kgf / cm 2 , and the hardening material injection step is performed by sequentially pulling up the injection pipe to the improved upper limit position, and the hardened material (diameter of about 2,
400, 10 m in length).
【００５１】切削工程では切削水の吐出量を２５０リッ
トル／分、引き上げ速度を１５秒／ピッチ（１ピッチ＝
２５mm）、硬化材注入工程では硬化材の吐出量を２７０
リットル／分、引き上げ速度を３０秒／ピッチに設定し
実施した。In the cutting step, the discharge amount of the cutting water is 250 liter / min, and the lifting speed is 15 seconds / pitch (1 pitch =
25 mm), and in the hardening material injection step, the discharge amount of the hardening material is 270.
The operation was carried out by setting the liter / minute and the lifting speed to 30 seconds / pitch.
【００５２】硬化材注入工程において地上に排出される
泥状物のＰＨ値を測定したところ９．６以下の値を示
し、また目視でもセメント分の排出は確認されず、硬化
材注入工程においてセメント分はほとんど排出されない
という良好な結果が得られた。When the pH value of the mud discharged to the ground in the hardening material injection step was measured, it showed a value of 9.6 or less, and no discharge of cement was confirmed by visual inspection. Good results were obtained with little emissions.
【００５３】さらに、造成数日後、地盤から硬化体を掘
り出し出来形の確認をしたところ、硬化体の下端部分に
おいても所定寸法の杭径が確保され、また採取したコア
サンプルの圧縮強度も７３Ｋｇｆ／cm2 と十分な強度を
有しており、未固結部分のない、寸法通りの硬化体が造
成できたことが確認された。Further, a few days after the formation, the hardened body was dug out from the ground and confirmed to be formed. As a result, a pile diameter of a predetermined size was secured at the lower end portion of the hardened body, and the compressive strength of the collected core sample was also 73 kgf / kg. It was confirmed that the cured product had a sufficient strength of cm 2, and had no unconsolidated portion, and could be formed according to dimensions.
【００５４】[0054]
【発明の効果】以上のとおり、本発明によれば、硬化材
混じりの泥状物を極力地上部に排出せず、しかも未固結
部分の生じない、計画寸法通りの硬化体を造成すること
ができるなどの利点がもたらされる。As described above, according to the present invention, it is possible to form a hardened body of the planned dimensions which does not discharge as much as possible the muddy material mixed with the hardening material to the above-ground portion and does not cause unconsolidated portions. And other advantages.
【図１】本発明の第１工程の説明図である。FIG. 1 is an explanatory view of a first step of the present invention.
【図２】本発明の第２工程の説明図である。FIG. 2 is an explanatory view of a second step of the present invention.
【図３】本発明の第３工程の説明図である。FIG. 3 is an explanatory view of a third step of the present invention.
【図４】本発明の第４工程の説明図である。FIG. 4 is an explanatory view of a fourth step of the present invention.
【図５】注入管例の縦断面図である。FIG. 5 is a longitudinal sectional view of an example of an injection tube.
１…注入管、２…削孔水硬化材用流路、３…高圧圧液用
流路、４…圧縮エア用流路４、５…削孔ビット、６…吐
出孔、７…硬化材噴射ノズル、８…切替えバルブ、９…
高圧噴射ノズル。DESCRIPTION OF SYMBOLS 1 ... Injection pipe, 2 ... Flow path for drilling water hardening material, 3 ... Flow path for high-pressure hydraulic fluid, 4 ... Flow path for compressed air 4,5 ... Drilling bit, 6 ... Discharge hole, 7 ... Hardening material injection Nozzle, 8 ... Switching valve, 9 ...
High pressure injection nozzle.
─────────────────────────────────────────────────────
────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成１１年３月５日（１９９９．３．５）[Submission date] March 5, 1999 (1999.3.5)
【手続補正１】[Procedure amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】全文[Correction target item name] Full text
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【書類名】明細書[Document Name] Statement
【発明の名称】高圧噴射地盤改良工法[Title of the Invention] High pressure injection ground improvement method
【特許請求の範囲】[Claims]
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【発明の属する技術分野】本発明は、予め高圧液により
地盤を切削し、泥状化した領域中にスラリー状の硬化材
を噴射し、この泥状化領域中での泥状物と前記硬化材を
混合するとともに余剰の泥状物を地上に排出して地盤中
に硬化体を造成する高圧噴射地盤改良工法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of cutting a ground with a high-pressure liquid in advance, injecting a slurry-like hardening material into a muddy region, and mixing the muddy material in the muddy region with the hardening material. The present invention relates to a high-pressure injection ground improvement method for mixing a material and discharging excess mud to the ground to form a hardened body in the ground.
【０００２】[0002]
【従来の技術】従来、高圧噴射地盤改良工法としては、
いわゆる「ＪＳＧ工法」や「コラムジェット工法」が主
流であり現在も多用されている。2. Description of the Related Art Conventionally, as a high-pressure injection ground improvement method,
The so-called “JSG method” and “column jet method” are mainstream and are still frequently used.
【０００３】「ＪＳＧ工法」とは、硬化材を噴射する核
ノズルと核ノズルの周囲を包囲しエアを噴射する包囲ノ
ズルとから構成される高圧噴射ノズルを先端部に設けた
注入管を地中に挿入し、この噴射ノズルからエアを伴っ
た硬化材を高圧噴射する工法である。[0003] The "JSG method" refers to an underground injection pipe provided with a high-pressure injection nozzle comprising a core nozzle for injecting a hardening material, and a surrounding nozzle for surrounding the core nozzle and injecting air. And a high-pressure injection of a hardening material accompanied by air from the injection nozzle.
【０００４】また「コラムジェット工法」とは、注入管
先端部の下段に設けた硬化材噴射ノズルとその上段に設
けた高圧水を噴射する核ノズルとその周囲を包囲しエア
を噴射する包囲ノズルとから構成される高圧水噴射ノズ
ルによって、まず上段の高圧水噴射ノズルからエアを伴
った高圧水を噴射し地盤を切削したのち、下段の硬化材
噴射ノズルから硬化材を噴射する工法である。[0004] The "column jet method" refers to a hardening material injection nozzle provided at a lower portion of a tip end portion of an injection pipe, a nucleus nozzle provided at an upper portion thereof for injecting high-pressure water, and an encircling nozzle for surrounding and injecting air around the nozzle. This is a method in which high pressure water with air is injected from the upper high pressure water injection nozzle to cut the ground, and then the hardening material is injected from the lower hardening material injection nozzle.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、これら
の工法はいずれも地盤中に噴射した硬化材（一般的には
セメント）が切削した泥状物に混じり、泥状物と一緒に
地上に大量に排出されるという問題があった。硬化材混
じりの泥状物は廃棄物としての処理が困難となるだけで
なく、地上に排出される硬化材は無駄となるため、材料
コストも嵩むことになる。However, in each of these methods, the hardening material (generally, cement) injected into the ground mixes with the cut mud, and a large amount of the hard material (generally cement) is put on the ground together with the mud. There was a problem of being discharged. Not only is it difficult to dispose of the mud containing the hardening material as waste, but also the hardening material discharged to the ground is wasted, thus increasing the material cost.
【０００６】さらに、地盤中において、硬化材と泥状物
とが混合された泥状混合物中では、その硬化前において
砂分が沈降してしまい、泥状化領域の下端付近に砂分が
滞積し、結果的に硬化材成分が少なくなり、その部分が
未固結となるという問題もあった。Furthermore, in a ground, in the hardened material and mud-like material and is mixed slurry mixture, will be Oite sand fraction is precipitated before its curing, the sand in the vicinity of the lower end of the mud region min to accumulate, resulting in hardener component is reduced, there is a problem that a portion thereof is unconsolidated.
【０００７】また、最近では、前述のような硬化材の排
出を抑制するため、エアを伴う高圧水による切削工程と
硬化材の注入工程を別工程で行う方法も提案されている
（たとえば特開平９−１４３９７５号公報）が、この方
法によっても硬化材の注入過程においては、硬化材が泥
状物に混じり地上に排出されてしまい、硬化材の排出を
止めることは不可能であった。Recently, a method has been proposed in which a cutting step using high-pressure water with air and a step of injecting the hardening material are performed in separate steps in order to suppress the discharge of the hardening material as described above. However, even in this method, in the process of injecting the hardening material, the hardening material is mixed with the muddy material and discharged to the ground, and it is impossible to stop the discharge of the hardening material.
【０００８】本発明は以上の問題点を鑑みてなされたも
ので、硬化材混じりの泥状物を極力地上部に排出せず、
しかも未固結部分の生じない、計画寸法通りの硬化体を
造成することのできる高圧噴射地盤改良工法を提案する
ことを課題とする。[0008] The present invention has been Do in view of the above problems, without discharging as much as possible to the ground portion of the slurry product of the curable material mingled,
In addition, it is an object of the present invention to propose a high-pressure injection ground improvement method capable of forming a hardened body having a planned size without an unconsolidated portion.
【０００９】[0009]
【課題を解決するための手段】前記課題を解決した本発
明の請求項１記載の発明は、高圧液、またはエアを伴っ
た高圧液を噴射することによって地盤を切削し、所定領
域を泥状化した後、この泥状化領域中に挿入した注入管
を、泥状化領域の下端部から上方に向かって上昇させる
過程で、１５０〜２０００ｍＰａ・ｓの粘度を有するス
ラリー状の硬化材を吐出し、前記泥状化領域の泥状物と
前記硬化材を混合するとともに余剰の泥状物を地上に排
出して地盤中に硬化体を造成することを特徴とする高圧
噴射地盤改良工法である。According to the first aspect of the present invention, which solves the above-mentioned problems, the ground is cut by jetting a high-pressure liquid or a high-pressure liquid accompanied by air, and a predetermined area is made muddy. After that, the injection pipe inserted into the muddy region is raised upward from the lower end of the muddy region, and a slurry-like hardening material having a viscosity of 150 to 2000 mPa · s is discharged. A high-pressure injection ground improvement method comprising mixing the muddy material in the muddy region and the hardening material and discharging excess muddy material to the ground to form a hardened body in the ground. .
【００１０】請求項２記載の発明は、高圧液を噴射する
核ノズルとこの核ノズルの周囲から圧縮エアを噴射する
包囲ノズルとを有する高圧噴射ノズルを先端部に設けた
注入管を地盤中に挿入した後、前記高圧噴射ノズルから
エアを伴った高圧液を側方に高圧噴射し、前記注入管を
回転させながら地盤改良上限位置まで引き上げ、地盤を
切削するとともにエアリフト効果により切削土砂を地上
に排出することによって所定の泥状化領域を形成し、さ
らに前記泥状化領域の下端部まで注入管を挿入した後、
この注入管を順次引き上げながらこの注入管の先端付近
から１５０〜２０００ｍＰａ・ｓの粘度を有するスラリ
ー状の硬化材を噴射し、前記泥状化領域の泥状物と前記
硬化材を混合するとともに余剰の泥状物を地上に排出し
て地盤中に硬化体を造成することを特徴とする高圧噴射
地盤改良工法である。According to a second aspect of the present invention, an injection pipe having a high-pressure injection nozzle having a core nozzle for injecting high-pressure liquid and a surrounding nozzle for injecting compressed air from the periphery of the core nozzle is provided in the ground. After the insertion, high-pressure liquid with air is injected from the high-pressure injection nozzle to the side at high pressure, and the injection pipe is rotated to pull up to the ground improvement upper limit position. After forming a predetermined muddy region by discharging, and further inserting the injection pipe to the lower end of the muddy region,
A slurry-like hardening material having a viscosity of 150 to 2,000 mPa · s is sprayed from the vicinity of the tip of the injection pipe while sequentially pulling up the injection pipe, and the slurry in the muddy region is mixed with the hardening material and excess A high-pressure injection ground improvement method characterized by discharging a muddy material to the ground to form a hardened body in the ground.
【００１１】請求項３記載の発明は、前記高圧液が１０
０〜７５０ｍＰａ・ｓの粘度を有するスラリー状の液体
であることを特徴とする請求項１または２記載の高圧噴
射地盤改良工法である。According to a third aspect of the present invention, the high-pressure liquid is 10
The high-pressure injection ground improvement method according to claim 1 or 2, wherein the method is a slurry-like liquid having a viscosity of 0 to 750 mPa · s.
【００１２】請求項４記載の発明は、前記硬化材の吐出
圧力が、その圧送ポンプの元圧で２０〜２００Ｋｇｆ／
cm2であることを特徴とする前記請求項１〜３のいずれ
か１項に記載の高圧噴射地盤改良工法である。According to a fourth aspect of the present invention, the discharge pressure of the hardening material is 20 to 200 kgf / at the original pressure of the pressure feed pump.
The high-pressure injection ground improvement method according to any one of claims 1 to 3, wherein the height is cm 2 .
【００１３】なお、本明細書における粘度はいずれもＢ
型回転粘度計による測定値を基準とする。The viscosity in this specification is B
Based on the value measured by a mold rotational viscometer.
【００１４】[0014]
【発明の実施の形態】本発明の主たる特徴の第１は、予
め地盤を泥状化し、その地盤にスラリー状の硬化材を吐
出させて、泥状化領域の泥状物と硬化材とを混合する点
であり、第２は、従来の前述の高圧噴射地盤改良工法に
用いられてきた噴射材はセメントミルクであり、その粘
度はきわめて小さいものであるのに対して、本発明にお
いては、粘度が１５０〜２０００ｍＰａ・ｓというきわ
めて高い粘度を有するスラリー状の硬化材を用いる点で
ある。BEST MODE FOR CARRYING OUT THE INVENTION The first of the main features of the present invention is that the ground is muddy in advance, a slurry-like hardening material is discharged onto the ground, and the muddy material and hardening material in the muddy region are separated. The second point is that the injection material used in the above-mentioned conventional high-pressure injection ground improvement method is cement milk, whose viscosity is extremely small, whereas in the present invention, The point is that a slurry-like hardening material having an extremely high viscosity of 150 to 2000 mPa · s is used.
【００１５】（施工形態）以下本発明に係る施工形態を
図面を参照しながらさらに詳説する。(Construction form) The construction form according to the present invention will be described in more detail with reference to the drawings.
【００１６】（１）削孔工程 本発明で使用する注入管１は、たとえば図５に示す注入
管１が用いられる。すなわち、注入管１は３流路管であ
り、中央に削孔水Ｗおよび硬化材Ｈ用流路２と高圧液Ｌ
用流路３と圧縮エアＡ用流路４の３流路を有し、その先
端部にはウイングビット等の削孔ビット５が取り付けら
れている。(1) Drilling Step As the injection pipe 1 used in the present invention, for example, the injection pipe 1 shown in FIG. 5 is used. That is, the injection pipe 1 is a three-flow pipe, and the drilling water W and the hardening material H flow path 2 and the high-pressure liquid L
There are three flow paths , i.e., a flow path 3 for compressed air and a flow path 4 for compressed air A, and a drill bit 5 such as a wing bit is attached to a tip end thereof.
【００１７】この削孔ビットには、削孔水Ｗを吐出させ
る吐出孔６が形成されている。この上部には、硬化材噴
射ノズル７が設けられている。この硬化材噴射ノズル７
と吐出孔６の流路方向の切替えは、注入管先端に内蔵さ
れた切替バルブ８により行われる。この切替えバルブ８
は、反発スプリング８Ａと基部側に付勢された弁座８Ｂ
とこの弁座８Ｂに向かって投入されるボール８Ｃとによ
り構成され、削孔水Ｗの供給時には、ボール８Ｃは投入
されていないので、供給される削孔水Ｗは、流路２を通
してそのまま吐出孔６から吐出される。硬化材Ｈの供給
に際しては、ボール８Ｃが投入され、その結果、切替え
バルブ８より先端側がボール８Ｃにより封止されるの
で、供給された硬化材Ｈは硬化材噴射ノズル７から噴出
されるようになる。The drilling bit is formed with a discharge hole 6 for discharging drilling water W. Above this, a hardener injection nozzle 7 is provided. This hardener injection nozzle 7
The switching of the flow direction of the discharge hole 6 and the discharge hole 6 is performed by a switching valve 8 built in the tip of the injection pipe. This switching valve 8
Is a resilient spring 8A and a valve seat 8B biased to the base side.
And the ball 8C to be thrown toward the valve seat 8B. When the drilling water W is supplied, since the ball 8C is not thrown, the supplied drilling water W is directly discharged through the flow path 2. Discharged from the hole 6. When the hardening material H is supplied, the ball 8C is thrown in, and as a result, the tip side of the switching valve 8 is sealed by the ball 8C, so that the supplied hardening material H is ejected from the hardening material injection nozzle 7. Become.
【００１８】さらに、硬化材噴射ノズル７の上方位置に
は高圧液Ｌ用流路３に連通した高圧液噴射用核ノズル９
Ａと、圧縮エア用流路４に連通し、前記核ノズル９Ａの
周囲を包囲しエアＡを噴射する包囲ノズル９Ｂとから構
成された、エアを伴う高圧液を側方に高圧噴射するため
の高圧噴射ノズル９が上下２ヶ所に相反する方向に噴射
するように設けられている。下部側の高圧噴射ノズル９
は所定角度斜め上向きに、一方、上部側の高圧噴射ノズ
ル９は所定角度斜め下向きに設けられている。Further, a high-pressure liquid injection core nozzle 9 communicating with the high-pressure liquid L flow path 3 is located above the hardening material injection nozzle 7.
A and a surrounding nozzle 9B which communicates with the compressed air flow path 4 and surrounds the core nozzle 9A and injects the air A. A high-pressure injection nozzle 9 is provided so as to inject in two opposite directions in opposite directions. Lower high-pressure injection nozzle 9
Is directed obliquely upward at a predetermined angle, while the upper high-pressure injection nozzle 9 is provided obliquely downward at a predetermined angle.
【００１９】さて、図１に示すように、かかる注入管１
を用い、ボーリングマシン等の削孔装置１０を用い、前
記注入管１先端の吐出孔６から削孔水Ｗを吐出させなが
ら地盤改良予定下限位置に、注入管１の先端部が到達す
るまで地盤を削孔し、この注入管１を所定位置に配置す
る。Now, as shown in FIG.
Using a drilling machine 10 such as a boring machine, while discharging drilling water W from the discharge hole 6 at the tip of the injection pipe 1, the ground is maintained until the tip of the injection pipe 1 reaches the ground improvement planned lower limit position. And the injection pipe 1 is arranged at a predetermined position.
【００２０】（２）一次切削工程 次いで、図２に示すように、地盤改良予定下限位置か
ら、高圧噴射ノズル９，９からエアを伴った高圧液を側
方に高圧噴射させながら、注入管１を地盤改良上限位置
まで回転させながら引き上げることによって地盤を切削
するとともに、圧縮エアの同伴に伴うエアリフト効果に
より切削土砂を地上に排出し、泥状の地盤改良予定領域
を形成する。(2) Primary Cutting Step Next, as shown in FIG. 2, the injection pipe 1 is injected from the high-pressure injection nozzles 9, 9 while the high-pressure liquid with air is injected at high pressure from the ground improvement planned lower limit position to the side. The ground is cut by rotating it up to the ground improvement upper limit position and cutting the ground, and the cut soil is discharged to the ground by the air lift effect accompanying the compressed air to form a muddy ground improvement scheduled area.
【００２１】この際使用する高圧液（切削水）Ｌとして
はこの切削工程で形成した泥状化領域の孔壁保持性およ
び硬化材注入工程時における置換性の点から、増粘剤が
添加された１００〜７５０ｍＰａ・ｓの範囲の粘度を有
するものが好適である。粘度が１００ｍＰａ・ｓより低
いと泥状化領域Ｚの孔壁が崩壊しやすくなり、また７５
０ｍＰａ・ｓより高くなると後工程での硬化材が目標域
に注入されず、上方に逸走して余剰泥状物と一緒に排出
されてしまう傾向が大きい。As the high-pressure liquid (cutting water) L used at this time, a thickener is used in view of the hole wall retaining property of the muddy region formed in this cutting step and the substitution property in the hardening material injection step. The added one having a viscosity in the range of 100 to 750 mPa · s is preferable. When the viscosity is lower than 100 mPa · s, the pore wall of the muddy zone Z is apt to collapse,
When the pressure is higher than 0 mPa · s, the hardening material in the post-process is not injected into the target area, but tends to run upward and be discharged together with the excess mud.
【００２２】この点については後述の実験例においてさ
らに説明する。ここで使用する増粘剤としてはセルロー
ス系、アクリル系、天然高分子系、繊維状鉱物系など種
々のものを使用することができる。This point will be further described in an experimental example described later. As the thickener used here, various types such as a cellulose type, an acrylic type, a natural polymer type, a fibrous mineral type and the like can be used.
【００２３】また、高圧液も噴射圧力は、この高圧液を
圧送する高圧ポンプ１１の元圧で約２００〜７００Ｋgf
／cm2 、一方、圧縮エアの圧力はエアを搬送するコンプ
レッサ１２の元圧で５〜１０Ｋｇｆ／cm2に設定するの
が好適である。The injection pressure of the high-pressure liquid is about 200 to 700 kgf at the original pressure of the high-pressure pump 11 for pumping the high-pressure liquid.
/ Cm 2, on the other hand, the pressure of the compressed air is preferably set to 5 to 10 kgf / cm 2 as the original pressure of the compressor 12 for conveying the air.
【００２４】地上部に排出された切削液と土砂の混合物
からなる排泥Ｍは、排泥ポンプ装置１３によりピットか
ら脱水装置（図示せず）に送り込んで、土砂分と液状分
とに分離し、分離した液状分はさらに凝集処理等を施
し、切削液や削孔水として再利用するのが望ましい。切
削工程で排出される泥状物には硬化材がほとんど含まれ
ていないため、再利用のための処理がしやすい。一方、
分離した土砂分はダンプトラック等で搬出し適正に処分
する。The sludge M composed of a mixture of cutting fluid and earth and sand discharged to the ground is sent from a pit to a dehydrator (not shown) by a sludge pumping device 13 to be separated into earth and sand and liquid. It is preferable that the separated liquid is subjected to a coagulation treatment or the like and reused as a cutting fluid or drilling water. Since the hard material is hardly contained in the mud discharged in the cutting process, it can be easily processed for reuse. on the other hand,
The separated sediment should be carried out by dump trucks and disposed of properly.
【００２５】（３）注入管再挿入工程 その後、図３に示すように、注入管１を前工程により形
成した泥状化領域Ｚの中に注入管１の先端部が地盤改良
予定下限位置に達するまで建て込む。(3) Injection Pipe Reinsertion Step Thereafter, as shown in FIG. 3, the tip end of the injection pipe 1 is located at the lower limit of the ground improvement scheduled in the muddy region Z formed by the previous step. Build until you reach.
【００２６】泥状化領域Ｚの孔壁が崩壊したり、砂分の
沈降により下端に砂分が滞積している場合には、注入管
１の下降時に高圧液を噴射し、再攪拌し、沈降した砂分
をこの泥状化領域Ｚ中に再浮遊、再分散させる。こうす
ることによって、後工程の硬化材注入がし易くなる。If the pore wall of the muddy zone Z has collapsed or sand has accumulated at the lower end due to sedimentation of the sand, high-pressure liquid is injected when the injection pipe 1 descends, and the liquid is stirred again. The sedimented sand is resuspended and redispersed in the muddy zone Z. This makes it easier to inject the hardening material in a later step.
【００２７】（４）硬化材噴射工程 次に、図４に示すように、注入管１を順次引き上げなが
ら、グラウトポンプ１４により硬化材Ｈを注入管１内に
送り込んで、その先端付近の硬化材噴射ノズル７からス
ラリー状の硬化材Ｈを噴射し、泥状化領域Ｚの泥状物と
硬化材Ｈを混合するとともに余剰の泥状物を地上に排出
して地盤中に硬化体を造成する。(4) Curing Material Injecting Step Next, as shown in FIG. 4, the grout pump 14 feeds the hardening material H into the filling tube 1 while sequentially pulling up the filling tube 1, and the hardening material near the tip thereof. The slurry-like hardening material H is sprayed from the spray nozzle 7 to mix the muddy material in the muddy region Z and the hardening material H, and discharge excess muddy material to the ground to form a hardened material in the ground. .
【００２８】この硬化材としては、注入した硬化材を目
標域に確実に注入させ、上方に逸走するのを防ぐため
に、水／セメント比１００％のセメントスラリーに対
し、増粘剤の添加された１５０〜２０００ｍＰａ・ｓの
範囲の粘度を呈するものを使用し、特に２５０〜５００
ｍＰａ・ｓの粘度を呈するものが好適である。As this hardening material, a thickener was added to a cement slurry having a water / cement ratio of 100% in order to ensure that the injected hardening material was injected into the target area and to prevent upward runaway. Use a material exhibiting a viscosity in the range of 150 to 2000 mPa · s, particularly 250 to 500
Those exhibiting a viscosity of mPa · s are preferred.
【００２９】粘度が１５０ｍＰａ・ｓより低いと、泥状
化領域中に注入した硬化材が上方に逸走しやすく、硬化
材混じりの泥状物が排出されてしまう。一方、２０００
ｍＰａ・ｓより高くすると、使用する増粘剤の添加量が
過剰となりコスト高になるとともに粘性が高すぎて硬化
材の圧送ラインで閉塞トラブルが発生しやすくなる。こ
の点については後述の実験結果とともに説明する。ま
た、ここで使用する増粘剤としてはセルロース系、アク
リル系、天然高分子系、繊維状鉱物系など種々のものを
使用することができる。If the viscosity is lower than 150 mPa · s, the hardened material injected into the muddy region easily escapes upward, and the mud mixed with the hardened material is discharged. On the other hand, 2000
If the pressure is higher than mPa · s, the amount of the thickener used is excessive and the cost is increased. In addition, the viscosity is too high, so that a blockage trouble easily occurs in the pressure feed line of the hardening material. This will be described together with experimental results described later. In addition, as the thickener used here, various types such as a cellulose type, an acrylic type, a natural polymer type, and a fibrous mineral type can be used.
【００３０】硬化材の吐出圧力は、グラウトポンプ１４
の元圧で２０〜２００Ｋｇｆ／cm2にするのが好適であ
り、切削工程での高圧液の吐出圧力よりかなり低圧力に
設定される。The discharge pressure of the hardening material is controlled by the grout pump 14.
The source pressure is preferably 20 to 200 kgf / cm 2 , and is set to a pressure considerably lower than the discharge pressure of the high-pressure liquid in the cutting process.
【００３１】（実験例） ＜実験１：硬化材の排出状況および砂分の沈澱状況に関
する実験＞本実験は、本発明の硬化材注入工程を想定し
た模擬実験であり、硬化材の粘性を変化させた場合にお
ける、余剰泥状物に混入し排出される硬化材の排出状況
の違いを調べたものである。(Experimental Example) <Experiment 1: Experiment on the state of discharge of hardened material and the state of precipitation of sand> This experiment is a simulation experiment assuming the hardening material injection step of the present invention, and changes the viscosity of the hardened material. In this case, the difference in the state of discharge of the hardened material mixed in and discharged from the excess mud is examined.
【００３２】人工的に作成した模擬泥状化領域中に注入
管を挿入し、その先端から異なる粘性を呈する硬化材を
側方に吐出（吐出量１０リットル／分）しながら注入管
を１分あたり２００mmピッチで順次引き上げることによ
って、硬化材を前記領域中に注入し、その際排出される
余剰泥状物の各ステップ毎のＰＨ値および注入した硬化
材中における砂分の沈澱厚さを測定し、その結果を表１
に示した。An injection tube is inserted into the artificially formed simulated muddy region, and the injection tube is discharged for 1 minute while discharging a hardening material having a different viscosity to the side (discharge amount 10 liter / min) from the tip. The hardening material is injected into the above-mentioned area by sequentially pulling the hardening material at a pitch of 200 mm, and the PH value of each step of the excess sludge discharged at that time and the sediment thickness of the sand in the injected hardening material are measured. Table 1 shows the results.
It was shown to.
【００３３】使用硬化材は水：セメント比が１００％の
セメントスラリーに対し増粘剤を添加量を変化させて加
え、種々の粘性に調整したものである。The hardening material used is prepared by adding a thickener to a cement slurry having a water: cement ratio of 100% by changing the amount of addition to adjust the viscosity to various values.
【００３４】またこの模擬泥状物領域は、エアを伴った
高圧水を噴射し砂質土地盤を切削した際に形成される泥
状化領域を想定したものであり、砂１重量部と水１重量
部とを混合した泥状物（比重約１．３５）を直径５００
mm、高さ１２００mmの透明なアクリル製の円筒管に充填
し作成したものである。増粘剤としては、セルロース系
増粘剤（商品ＭＪ−２：日東化学工業社製）と繊維状粘
土鉱物系増粘剤（「アタパルジャイト」：ユニオン化成
社製）の２種類を使用した。The simulated muddy area is assumed to be a muddy area formed when high-pressure water with air is injected to cut sandy ground, and 1 part by weight of sand and water 1 part by weight and a slurry (specific gravity of about 1.35) is mixed with a powder having a diameter of 500.
It was prepared by filling a transparent acrylic cylindrical tube with a height of 1200 mm and a height of 1200 mm. The thickener, a cellulose-based thickener (product MJ-2: Nitto Chemical Industry Co., Ltd.) and the fibrous clay mineral-based thickener: using two kinds of ( "attapulgite" Union Chemical Co., Ltd.).
【００３５】なお、表１に示す粘度はＢ型粘度計での計
測値である。また泥状物のＰＨ値は、排出される泥状物
に対する硬化材分の混入状況を確認するためのものであ
り、ＰＨ値１１以上になるとかなりのセメント分が含ま
れていると推測される。さらに沈澱の厚さは、硬化材の
注入完了後１５分経過した時点での前記円筒管下部に沈
降した砂分の厚さを計測したものである。The viscosities shown in Table 1 are values measured with a B-type viscometer. Further, the PH value of the muddy substance is for confirming the mixing state of the hardening material in the discharged muddy substance, and it is assumed that when the PH value is 11 or more, a considerable amount of cement is contained. . Further, the thickness of the precipitate is obtained by measuring the thickness of the sand that has settled at the lower portion of the cylindrical tube at the time when 15 minutes have elapsed after the completion of the injection of the hardening material.
【００３６】[0036]
【表１】 [Table 1]
【００３７】表１の結果から、セルロース系、繊維状粘
土鉱物系どちらの増粘剤においても粘度を１５０ｍＰａ
・ｓ以上にすれば、排泥水のＰＨ値１１以下、砂分の沈
澱厚さ約１０cm前後となり、ほぼ良好な結果が得られ、
さらに粘度を２５０ｍＰａ・ｓ以上にすれば、ＰＨ値１
０以下、砂分の沈澱厚さ１０cm以下となり、さらに良好
な結果が得られることが分かる。From the results shown in Table 1, it was found that the viscosity of both the cellulosic and fibrous clay mineral thickeners was 150 mPa.
-If it is more than s, the pH value of the wastewater is 11 or less, the sediment thickness of the sand is about 10 cm, and almost good results are obtained.
Further, if the viscosity is set to 250 mPa · s or more, a PH value of 1
0 or less, the sediment thickness of the sand was 10 cm or less, and it can be seen that even better results were obtained.
【００３８】＜実験２：孔壁保持性実験＞本実験は、高
圧液（切削水）により地盤を切削した際に形成される泥
状化領域を想定した模擬実験であり、使用する切削水の
粘性を変化させた際の、泥状化領域の孔壁安定性の違い
を調べたものである。<Experiment 2: Hole Wall Retention Experiment> This experiment is a simulation experiment assuming a muddy region formed when the ground is cut by high-pressure liquid (cutting water). Difference in pore wall stability in muddy area when viscosity is changed
It is a thing which investigated.
【００３９】まず縦３５０mm×横５５０mm×高さ４００
mmの容器に砂を敷き詰めて模擬地盤（相対密度３０％、
密度１．６ｇ／cm 3 ，飽和度１００％）を作り、この模
擬地盤に予め建て込んでおいた直径５０mmの中空パイプ
内に種々の粘度を有する模擬切削水を充填したのち、パ
イプを地盤から引き抜くことによって模擬泥状化領域を
形成し、次いでこの模擬泥状化領域にセメントミルクを
充填し、その結果形成される硬化体の形状から孔壁保持
性を確認するという方法で、切削水の粘性を変化させた
際の孔壁保持性の違いを調べたものである。その結果を
表２に示した。First, height 350 mm × width 550 mm × height 400
simulated ground (30% relative density,
Density 1.6 g / cm 3 , A saturation degree of 100%), and simulated cutting water having various viscosities is filled in a hollow pipe having a diameter of 50 mm previously laid on the simulated ground, and then the pipe is pulled out of the ground to form a simulated muddy state. An area is formed, and then the simulated muddy area is filled with cement milk, and the viscosity of the cutting water is changed by a method of confirming the hole wall retention from the shape of the resulting hardened body. The difference in pore wall retention was examined. The results are shown in Table 2.
【００４０】この疑似切削水は、清水（Ｗ）に添加量を
変えて増粘剤を加え、種々の粘性に調整したものであ
る。増粘剤としては、ポリアニオン化セルロース系増粘
剤（商品名「ＤＫ−ハイポリマー」：第一工業製薬社
製）とセルロース系増粘剤（商品名「ＭＪ−２」：日東
化学工業社製）の２種類を使用した。This simulated cutting water is prepared by adding a thickening agent to fresh water (W) by changing the amount of addition, and adjusting the viscosity to various viscosities. Is as a thickening agent, polyanionic cellulosic thickener (trade name "DK- high polymer": Dai-ichi Kogyo Seiyaku Co., Ltd.) and cellulose-based thickener (trade name "MJ-2": Nitto Chemical Industry using two types of company, Ltd.).
【００４１】[0041]
【表２】 [Table 2]
【００４２】実験２の結果から増粘剤の種類に関係な
く、疑似切削水の粘度を１００ｍＰａ・ｓ程度以上にす
ればほぼ孔壁保持が図れることが判る。From the results of Experiment 2, it can be seen that, regardless of the type of the thickener, if the viscosity of the simulated cutting water is about 100 mPa · s or more, the hole wall can be substantially retained.
【００４３】＜実験３：切削水の粘性の違いによる硬化
材の置換性に関する実験＞本実験は、実験１と同様に本
発明の硬化材注入工程を想定した模擬実験であり、硬化
材の粘性を変化させた場合における、余剰泥状物に混入
し排出される硬化材の排出状況の違いを調べたものであ
る。<Experiment 3: Experiment on Replacement of Hardened Material Due to Difference in Viscosity of Cutting Water> This experiment is a simulation experiment assuming the hardening material injection step of the present invention as in Experiment 1, and the viscosity of the hardened material is This is to examine the difference in the state of discharge of the hardened material mixed in and discharged from the surplus mud when changing.
【００４４】粘性の異なる疑似切削水１重量部と砂１重
量部とを混合し、種々の粘性に調整した実験１と同様な
模擬泥状化領域を作成し、その泥状化領域に対し注入管
を挿入し、次いで、セルロース系増粘剤を添加し粘度２
５０ｍＰａ・ｓに調整した硬化材を吐出（吐出量１０リ
ットル／分）しながら、注入管を１分あたり２００mmピ
ッチで順次引き上げることによって硬化材を前記領域中
に注入し、その際排出される泥状物のＰＨ値を各ステッ
プ毎に測定し、硬化材の排出状況を調べた。その結果を
表３に示した。1 part by weight of simulated cutting water having different viscosities and 1 part by weight of sand were mixed to prepare a simulated muddy region similar to that of Experiment 1 in which the viscosities were adjusted to various viscosities, and injected into the muddy region. Insert the tube, then add the cellulosic thickener and add
While discharging the curing material adjusted to 50 mPa · s (discharge amount 10 liter / min), the injection material is injected into the region by sequentially pulling up the injection pipe at a pitch of 200 mm per minute, and the mud discharged at that time is discharged. The PH value of the material was measured at each step, and the state of discharge of the hardened material was examined. Table 3 shows the results.
【００４５】[0045]
【表３】 [Table 3]
【００４６】この結果から、疑似切削水の粘度を７５０
ｍＰａ・ｓ以下にすれば、排泥水のＰＨ値は約１０以下
となり、排泥水に伴う硬化材の排出を防ぐことが可能で
あることが分かる。７５０ｍＰａ・ｓより粘度を高くし
た場合にはＰＨ値は１１以上を示し、目視でも注入管の
周囲からの硬化材の排出が確認された。これは、切削水
の粘度を高くし過ぎると、注入管から吐出した硬化材が
目標域に注入されずに上方に逸走しやすくなるためと推
定される。From the results, it was found that the viscosity of the pseudo cutting water was 750.
When the pressure is set to mPa · s or less, the pH value of the wastewater becomes about 10 or less, and it is understood that the discharge of the hardening material accompanying the wastewater can be prevented. When the viscosity was higher than 750 mPa · s, the PH value was 11 or more, and discharge of the hardened material from the periphery of the injection tube was visually confirmed. This is presumed to be because if the viscosity of the cutting water is too high, the hardened material discharged from the injection pipe tends to escape upward without being injected into the target area.
【００４７】[0047]
【実施例】図１〜図４に示す工程をもって、図５に示す
注入管を用いて砂質地盤を対象に本発明の実験を行っ
た。EXAMPLE An experiment of the present invention was conducted on the sandy ground using the injection pipe shown in FIG. 5 in the steps shown in FIGS.
【００４８】まず、注入管を砂質地盤中に建て込み、注
入管の核ノズルから清水に重量比０．８％のセルロース
系増粘剤（商品名ＭＪ−２：日東化学工業社製）を添加
し、粘度１８０ｍＰａ・ｓに調整した切削水を４００Ｋ
gf／cm 2 の圧力で、一方、包囲ノズルから圧縮空気を７
Ｋｇｆ／cm2の圧力で噴射することよって切削工程を実
施した。First, an injection pipe is built in sandy ground, and a 0.8% by weight cellulose-based thickener (trade name: MJ-2: manufactured by Nitto Chemical Industry Co., Ltd.) is added to fresh water from a core nozzle of the injection pipe. 400 K of cutting water added and adjusted to a viscosity of 180 mPa · s
At a pressure of gf / cm 2 , compressed air from the surrounding nozzle
The cutting step was performed by jetting at a pressure of Kgf / cm 2 .
【００４９】次いで切削工程で泥状化した地盤の下端ま
で注入管を再度挿入し、注入管を回転させながら硬化材
噴射ノズルから水：セメント比１００％のセメントスラ
リーに重量比０．６％のセルロース系増粘剤（商品名Ｍ
Ｊ−２：日東化学工業社製）を添加し、粘度４００ｍＰ
ａ・ｓに調整した硬化材を５０Ｋｇｆ／cm2の圧力で吐
出させ、改良上限位置まで注入管を順次引き上げること
によって硬化材注入工程を実施し、硬化体（直径約２，
４００ｍ，長さ１０ｍ）の造成を行った。Next, the injection pipe is inserted again to the lower end of the ground which has been made muddy in the cutting step, and while the injection pipe is being rotated, the cement slurry having a water: cement ratio of 100% is added to the cement slurry having a water: cement ratio of 0.6% by rotating the injection pipe. Cellulose thickener (trade name M
J-2: manufactured by Nitto Chemical Industry Co., Ltd.), and the viscosity was 400 mP.
The hardening material adjusted to a · s is discharged at a pressure of 50 kgf / cm 2 , and the hardening material injection step is performed by sequentially pulling up the injection pipe to the improved upper limit position, and the hardened material (diameter of about 2,
(400 m , length 10 m).
【００５０】切削工程では切削水の吐出量を２５０リッ
トル／分、引き上げ速度を１５秒／ピッチ（１ピッチ＝
２５mm）、硬化材注入工程では硬化材の吐出量を２７０
リットル／分、引き上げ速度を３０秒／ピッチに設定し
実施した。In the cutting step, the discharge amount of the cutting water is 250 liter / min, and the lifting speed is 15 seconds / pitch (1 pitch =
25 mm), and in the hardening material injection step, the discharge amount of the hardening material is 270.
The operation was carried out by setting the liter / minute and the lifting speed to 30 seconds / pitch.
【００５１】硬化材注入工程において地上に排出される
泥状物のＰＨ値を測定したところ９．６以下の値を示
し、また目視でもセメント分の排出は確認されず、硬化
材注入工程においてセメント分はほとんど排出されない
という良好な結果が得られた。さらに、造成数日後、地
盤から硬化体を掘り出し出来形の確認をしたところ、硬
化体の下端部分においても所定寸法の杭径が確保され、
また採取したコアサンプルの圧縮強度も７３Ｋｇｆ／cm
2と十分な強度を有しており、未固結部分のない、寸法
通りの硬化体が造成できたことが確認された。When the pH value of the mud discharged to the ground in the hardening material injection step was measured, it showed a value of 9.6 or less. No discharge of cement was confirmed by visual inspection. Good results were obtained with little emissions. Furthermore, a few days after the formation, when the hardened body was dug out from the ground and checked for possible formation, a pile diameter of a predetermined size was secured even at the lower end portion of the hardened body,
Also, the compressive strength of the collected core sample was 73 kgf / cm.
It was confirmed that a cured product having a sufficient strength of 2 and having no unconsolidated portion and having the dimensions was formed.
【００５２】[0052]
【発明の効果】以上のとおり、本発明によれば、硬化材
混じりの泥状物を極力地上部に排出せず、しかも未固結
部分の生じない、計画寸法通りの硬化体を造成すること
ができるなどの利点がもたらされる。As described above, according to the present invention, it is possible to form a hardened body of the planned dimensions which does not discharge as much as possible the muddy material mixed with the hardening material to the above-ground portion and does not cause unconsolidated portions. And other advantages.
【図面の簡単な説明】[Brief description of the drawings]
【図１】本発明の第１工程の説明図である。FIG. 1 is an explanatory view of a first step of the present invention.
【図２】本発明の第２工程の説明図である。FIG. 2 is an explanatory view of a second step of the present invention.
【図３】本発明の第３工程の説明図である。FIG. 3 is an explanatory view of a third step of the present invention.
【図４】本発明の第４工程の説明図である。FIG. 4 is an explanatory view of a fourth step of the present invention.
【図５】注入管例の縦断面図である。FIG. 5 is a longitudinal sectional view of an example of an injection tube.
【符号の説明】 １…注入管、２…削孔水硬化材用流路、３…高圧液用流
路、４…圧縮エア用流路４、５…削孔ビット、６…吐出
孔、７…硬化材噴射ノズル、８…切替えバルブ、９…高
圧噴射ノズル。[Description of Reference Numerals] 1 ... injection tube, 2 ... drilling water curable material passage, 3 ... high pressure liquid flow path, 4 ... channel 4,5 ... bit boring for compressed air, 6 ... discharge hole, 7 ... hardening material injection nozzle, 8 ... switching valve, 9 ... high pressure injection nozzle.
Claims (4)
することによって地盤を切削し、所定領域を泥状化した
後、 この泥状化領域中に挿入した注入管を、泥状化領域の下
端部から上方に向かって上昇させる過程で、１５０〜２
０００ｍＰａ・ｓの粘度を有するスラリー状の硬化材を
吐出し、前記泥状化領域の泥状物と前記硬化材を混合す
るとともに余剰の泥状物を地上に排出して地盤中に硬化
体を造成することを特徴とする高圧噴射地盤改良工法。1. A ground is cut by injecting a high-pressure liquid or a high-pressure liquid accompanied by air, a predetermined area is muddy, and an injection pipe inserted into the muddy area is muddy. In the process of ascending upward from the lower end of the region, 150 to 2
Discharge a slurry-like hardening material having a viscosity of 000 mPa · s, mix the muddy material in the muddy region with the hardening material, and discharge excess muddy material to the ground to form a hardened material in the ground. A high-pressure injection ground improvement method characterized by construction.
の周囲から圧縮エアを噴射する包囲ノズルとを有する高
圧噴射ノズルを先端部に設けた注入管を地盤中に挿入し
た後、 前記高圧噴射ノズルからエアを伴った高圧液を側方に高
圧噴射し、前記注入管を回転させながら地盤改良上限位
置まで引き上げ、地盤を切削するとともにエアリフト効
果により切削土砂を地上に排出することによって所定の
泥状化領域を形成し、 さらに前記泥状化領域の下端部まで注入管を挿入した
後、この注入管を順次引き上げながらこの注入管の先端
付近から１５０〜２０００ｍＰａ・ｓの粘度を有するス
ラリー状の硬化材を噴射し、前記泥状化領域の泥状物と
前記硬化材を混合するとともに余剰の泥状物を地上に排
出して地盤中に硬化体を造成することを特徴とする高圧
噴射地盤改良工法。2. An injection pipe having a high-pressure injection nozzle having a core nozzle for injecting a high-pressure liquid and a surrounding nozzle for injecting compressed air from around the core nozzle is inserted into the ground. A high-pressure liquid with air is injected from the injection nozzle to the side at a high pressure, and the injection pipe is rotated to lift the ground to the upper limit of the ground improvement, cutting the ground and discharging the cut soil by the air lift effect to a predetermined level. After forming a muddy region, and further inserting an injection pipe to the lower end of the muddy region, a slurry having a viscosity of 150 to 2000 mPa · s from the vicinity of the tip of the injection pipe while sequentially pulling up the injection pipe. The hardening material is sprayed, and the muddy material in the muddy region is mixed with the hardening material, and excess muddy material is discharged to the ground to form a hardened body in the ground. High-pressure injection ground improvement method that.
粘度を有するスラリー状の液体であることを特徴とする
請求項１または２記載の高圧噴射地盤改良工法。3. The high-pressure injection ground improvement method according to claim 1, wherein the high-pressure liquid is a slurry-like liquid having a viscosity of 100 to 750 mPa · s.
の元圧で２０〜２００Ｋｇｆ／cm2 であることを特徴と
する前記請求項１〜３のいずれか１項に記載の高圧噴射
地盤改良工法。4. The high-pressure jetting ground according to claim 1, wherein a discharge pressure of the hardening material is 20 to 200 kgf / cm 2 at a source pressure of the pressure pump. Improved construction method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22570998A JP3317902B2 (en) | 1998-08-10 | 1998-08-10 | High pressure injection ground improvement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22570998A JP3317902B2 (en) | 1998-08-10 | 1998-08-10 | High pressure injection ground improvement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000054365A true JP2000054365A (en) | 2000-02-22 |
| JP3317902B2 JP3317902B2 (en) | 2002-08-26 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22570998A Expired - Fee Related JP3317902B2 (en) | 1998-08-10 | 1998-08-10 | High pressure injection ground improvement method |
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| Country | Link |
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| JP (1) | JP3317902B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003027399A1 (en) * | 2001-09-20 | 2003-04-03 | Yugenkaisha Newtechkenkyusha | Ground improving construction method and ground improving device |
| JP2014062365A (en) * | 2012-09-20 | 2014-04-10 | Hazama Ando Corp | Method for creating fiber-mixed soil improvement body, and creation pipe used for the same |
| JP2021059898A (en) * | 2019-10-07 | 2021-04-15 | 学校法人早稲田大学 | Cutting composition, and high pressure injection stirring method using the same |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102817348B (en) * | 2012-08-31 | 2014-10-01 | 宝钢工程技术集团有限公司 | Treatment method of recent dredger-fill silt foundation |
-
1998
- 1998-08-10 JP JP22570998A patent/JP3317902B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003027399A1 (en) * | 2001-09-20 | 2003-04-03 | Yugenkaisha Newtechkenkyusha | Ground improving construction method and ground improving device |
| JP2014062365A (en) * | 2012-09-20 | 2014-04-10 | Hazama Ando Corp | Method for creating fiber-mixed soil improvement body, and creation pipe used for the same |
| JP2021059898A (en) * | 2019-10-07 | 2021-04-15 | 学校法人早稲田大学 | Cutting composition, and high pressure injection stirring method using the same |
| JP7307650B2 (en) | 2019-10-07 | 2023-07-12 | 学校法人早稲田大学 | Cutting composition and high-pressure injection stirring method using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3317902B2 (en) | 2002-08-26 |
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