JP2799554B2 - Ground improvement method by forming starfish shaped column - Google Patents
Ground improvement method by forming starfish shaped columnInfo
- Publication number
- JP2799554B2 JP2799554B2 JP14933795A JP14933795A JP2799554B2 JP 2799554 B2 JP2799554 B2 JP 2799554B2 JP 14933795 A JP14933795 A JP 14933795A JP 14933795 A JP14933795 A JP 14933795A JP 2799554 B2 JP2799554 B2 JP 2799554B2
- Authority
- JP
- Japan
- Prior art keywords
- ground
- starfish
- ground improvement
- cross
- column
- 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.)
- Expired - Lifetime
Links
Landscapes
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、地盤改良工法について
のものであり、さらに詳しくは地表に垂直な方向に水平
な断面がヒトデ形柱を地中に形成することにより、地盤
の液状化を防止したり、大雨時の土石流を防止する地盤
改良工法に関するものである．BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement method, and more particularly, to a method for liquefying a ground by forming a starfish-shaped column in the ground with a horizontal section perpendicular to the surface of the ground. It relates to ground improvement methods to prevent or prevent debris flow during heavy rain.
【０００２】[0002]
【従来技術】セメントミルク等の地盤改良薬液を注入し
て地盤に固結柱を形成することにより地盤を改良する工
法は既に公知であり、その代表的なものとして、ジェッ
ト・グラウト工法とケミカル・チューニング・パイル工
法とがある．ジェット・グラウト工法は、高圧噴流水と
それを取り囲むエアーとにより地盤を切削し、その空隙
に地盤改良薬液を注入充填する工法であり、この工法に
よれば噴流水の到達距離が伸び、広い範囲に渡って地盤
切削を行え、大口径の固結柱を形成できる利点がある
が、セメントが大量に必要であり高価となる上、大量の
切削スライムが地上に噴き上げるため、切削スライムの
処理などの問題が生じる．2. Description of the Related Art A method of improving a ground by injecting a ground improvement chemical such as cement milk to form a solidified column in the ground is already known, and typical examples thereof include a jet grout method and a chemical method. There is a tuning pile method. The jet grout method is a method in which the ground is cut with high-pressure jet water and the air surrounding it, and the space improvement chemical solution is injected and filled into the voids. Has the advantage of being able to perform ground cutting over a long period of time and form large-diameter solidified columns, but requires a large amount of cement and is expensive, and since a large amount of cutting slime is blown up to the ground, processing of cutting slime, etc. Problems arise.
【０００３】また、ケミカル・チューニング・パイル工
法は、地盤改良薬液を地盤中に高圧で噴射してその破壊
力で地盤を切削し、地盤中に地盤改良薬液の固結柱を造
成する工法であり、エアーを用いていないため切削スラ
イムが地上に吹き上げないので、切削スライムの処理の
問題は生じないが、地盤***が生じるうえ、地盤改良薬
液の到達距離が延びず、広い範囲に渡る地盤改良が行え
ないという問題がある．[0003] The chemical tuning pile method is a method in which a ground improvement chemical is injected into the ground at a high pressure to cut the ground by its destructive force, thereby forming a solidified column of the ground improvement chemical in the ground. Since no air is used, the cutting slime does not blow up to the ground, so there is no problem with the processing of the cutting slime.However, the ground is raised, and the reach of the ground improvement chemical solution is not extended, so the ground improvement over a wide area can be achieved. There is a problem that cannot be performed.
【０００４】この問題を解決する方法として、高圧で噴
射されるセメントミルクあるいはセメントパチルスなど
の地盤改良薬液をそれよりも低い圧力で噴射される水な
どの液体で囲むことにより地盤改良薬液と上砂との摩擦
抵抗を小さくし、これにより地盤改良薬液の到達距離を
増大させるようにしたものが特公昭５７−３８７２８号
公報に記載されている．しかし、この工法は大口径の固
結柱を形成できるが、掘削注入管が複雑であるし、セメ
ントが大量に必要であり高価となる上、大量のスライム
が地上に噴出しこれを投棄する必要があった．[0004] As a method of solving this problem, a ground improvement chemical such as cement milk or cement patills sprayed at a high pressure is surrounded by a liquid such as water sprayed at a lower pressure to form a ground improvement chemical. Japanese Patent Publication No. 57-37828 discloses a method in which the frictional resistance with sand is reduced to thereby increase the reach of a ground improvement chemical. However, this method can form large-diameter solidified columns, but it requires complicated drilling and injection pipes, requires a large amount of cement, is expensive, and requires a large amount of slime to erupt on the ground and be discarded. was there.
【０００５】[0005]
【解決すべき課題】そこで、本発明では、地盤改良薬液
の使用量が少なく、しかも、従来の簡単な装置を用いて
強固な地盤に改良できる地盤改良工法を開発することが
解決すべき課題である．Therefore, in the present invention, it is an object of the present invention to develop a ground improvement method that requires a small amount of ground improvement chemical solution and that can be improved into a solid ground using a conventional simple device. is there.
【０００６】[0006]
【解決するための手段】本発明では、上記課題を解決す
るために、本願出願人が開発し特許権を所有する無水堀
削刃付き無水掘削注入管を用いて無水削孔法により又は
有水削孔された孔を地盤改良薬液で孔埋した所を再び無
水掘削注入管を用いて無水削孔法により所定深さまで孔
をほり進め、その状態で該無水掘削注入管から高圧で水
を噴射し、その水が複数方向に飛び散ることにより地中
に複数の亀裂が入るようした後、該無水掘削注入管から
地盤改良薬液を注入してこの複数の亀裂中にそれを拡張
しながら侵入させて断面ヒトデ形の地盤改良柱を作る第
１工程と、無水掘削注入管を所定量上昇させた後、再び
該無水堀削注入管から地盤改良薬液を注入し、先に形成
されている断面ヒトデ形の地盤改良柱に連続して断面ヒ
トデ形の地盤改良柱を作る第２工程を行い、この第２工
程を繰り返して連続した断面ヒトデ形柱を形成すること
による地盤改良工法を開発した．According to the present invention, in order to solve the above-mentioned problems, an anhydrous drilling injection pipe with an anhydrous digging blade developed by the present applicant and having a proprietary patent is used, by an anhydrous drilling method or by a water drilling method. After drilling the drilled hole with the ground improvement chemical liquid, the hole is again drilled to a predetermined depth by the anhydrous drilling method using the anhydrous drilling injection pipe, and in this state, water is injected from the anhydrous drilling injection pipe at high pressure Then, after the water is scattered in a plurality of directions to cause a plurality of cracks in the ground, a ground improvement chemical solution is injected from the anhydrous excavation injection pipe to penetrate the plurality of cracks while expanding the same. A first step of forming a starfish-shaped ground improvement column, and after raising the anhydrous excavation injection pipe by a predetermined amount, the ground improvement chemical solution is injected again from the anhydrous excavation injection pipe to form the starfish cross-section formed earlier. Improvement of a starfish-shaped cross section following a soil improvement column Performing a second step of making, we have developed a ground improvement method by forming the second step sequential cross section starfish-shaped pillars Repeat.
【０００７】さらに、本発明では、無水堀削注入管によ
り無水削孔法により又は有水削孔された孔に地盤改良薬
液を注入した所を再び無水掘削注入管により無水削孔法
により所定深さまで孔をほり進め、その状態で該無水掘
削注入管から高圧で水を噴射し、その水がほぼ三方向に
飛び散ることにより地中に複数の亀裂が入るようした
後、該無水掘削注入管から地盤改良薬液を注入してこの
複数の亀裂中にそれを拡張しながら侵入させて断面ヒト
デ形の地盤改良柱を作る第１工程と、無水掘削注入管を
所定量上昇させた後、再び該無水掘削注入管から地盤改
良薬液を注入し、先に形成されている断面ヒトデ形の地
盤改良柱に連続して断面ヒトデ形の地盤改良柱を作る第
２工程を行い、この第２工程を繰り返して連続した断面
ヒトデ形柱を形成し上記第１工程と第２工程とを近接し
た複数箇所で行うことにより隣接した 断面ヒトデ形の
地盤改良柱の突出部分同志が互いに繋がるようにした断
面網目状楕造の地盤改良柱を形成することによる地盤改
良工法を開発した．Further, in the present invention, the place where the ground improvement chemical solution is injected into the hole drilled with water by the anhydrous drilling injection pipe by the anhydrous drilling injection pipe or by the anhydrous drilling injection pipe again to the predetermined depth by the anhydrous drilling injection pipe. In the state, water is injected at high pressure from the anhydrous drilling injection pipe, and the water scatters in almost three directions so that a plurality of cracks enter the ground. A first step of injecting the soil improvement chemical solution and expanding and invading the plurality of cracks into the plurality of cracks to form a starfish-shaped soil improvement cross section; A ground improvement chemical solution is injected from a drilling injection pipe, and a second step of continuously forming a starfish-shaped ground improvement column having a cross section starfish shape is performed, and the second step is repeated. Forming a continuous section starfish shaped column Performing the first step and the second step at a plurality of adjacent places to form a ground-improved pillar having a mesh-shaped cross-section in which the protruding portions of the adjacent star-shaped ground-improved pillars are connected to each other; Has developed a ground improvement method.
【０００８】[0008]
【実施例】図１、図２および図３は、本願発明の断面ヒ
トデ形柱形成による地盤改良工法を説明するためのもの
で、これら実施例では、断面ヒトデ形柱の一例として断
面が三つ葉形のものを示している。図１における１が無
水掘削が可能で地盤改良薬液及び水を噴射できる無水掘
削注入管、１０が地盤改良薬液供給装置、２０が水供給
装置である。また、図１におけるＡは地盤、Ｂは無水掘
削された孔、Ｃは連続した断面三つ葉形柱である。無水
掘削注入管１は、作業機２により上下動可能に支持され
ている。FIG. 1, FIG. 2 and FIG. 3 are for explaining the ground improvement method of the present invention by forming a starfish-shaped cross section. In these embodiments, a three-leaf cross-section is used as an example of a starfish-shaped cross section. Is shown. In FIG. 1, reference numeral 1 denotes an anhydrous excavation injection pipe capable of injecting waterless excavation and injecting ground improvement chemical liquid and water, 10 denotes a ground improvement chemical liquid supply device, and 20 denotes a water supply device. In addition, A in FIG. 1 is ground, B is a hole excavated under anhydrous conditions, and C is a continuous trefoil column having a cross section. The anhydrous drilling injection pipe 1 is supported by a work machine 2 so as to be vertically movable.
【０００９】図２は、地盤に形成された地表に垂直な連
続した断面三つ葉形柱が形成されている地盤を、地表に
平行な面で切断した断面図である。図における１は無水
掘削注入管であり、その周りには断面三つ葉形柱が適宜
間隔ごとに規則的に又はランダムに形成されている。FIG. 2 is a cross-sectional view of a ground formed with a continuous three-lobed column perpendicular to the ground formed on the ground, cut along a plane parallel to the ground. In the figure, reference numeral 1 denotes an anhydrous excavation injection pipe, around which trilobular columns are formed regularly or randomly at appropriate intervals.
【００１０】本発明で使用される無水掘削注入管は本願
特許出願人が特許権を所有する無水掘削刃付き無水削孔
注入管が適しているが、公知の無水削孔注入管も使用で
きる。先ず、無水削孔注入管で水を使わずに地中に孔を
開け、そのままの状態で該無水削孔注入管から例えば３
方向に水を４０ｋｇ／ｃｍ２の圧力で噴射する。する
と、３つのノズルから噴射された水は３方向に飛び散
り、地盤に３つ方向に亀裂を生じさせる。次に無水掘削
注入管に地盤改良薬液を例えば２０ｌ／分程度注入す
る。注入された地盤改良薬液は、その亀裂に沿って地盤
の中に侵入し、亀裂を押し広げ断面三つ葉状になって硬
化する。用いる地盤改良薬液はセメントと硅酸ソーダと
の混合液からなる瞬結グラウトを用いる。この瞬結グラ
ウトはセメント成分を多くすれば断面三つ葉形柱が永久
的になり、アルカリ溶脱もないので恒久性がある。尚、
瞬結グラウト材としては電化ＥＳ等セメント系のものも
色々使用できる。As the anhydrous drilling injection pipe used in the present invention, an anhydrous drilling injection pipe with an anhydrous drilling blade, which is a patent of the present applicant, is suitable, but a known anhydrous drilling injection pipe can also be used. First, a hole is drilled in the ground without using water with an anhydrous drilling injection pipe, and for example 3
Water is injected in the direction at a pressure of 40 kg / cm 2 . Then, the water jetted from the three nozzles scatters in three directions, causing cracks in the ground in three directions. Next, a ground improvement chemical solution is injected into the anhydrous excavation injection pipe at, for example, about 20 l / min. The injected soil improvement chemical liquid penetrates into the ground along the cracks, pushes the cracks, hardens into a three-lobed cross section. The ground improving chemical used is a flash grout composed of a mixture of cement and sodium silicate. If the cement component is increased, this flash grout becomes permanent because the trefoil column in section becomes permanent and there is no alkali leaching. still,
Various cement-based materials such as Electrified ES can be used as the instantaneously setting grout material.
【００１１】上記第１行程が終わったら、無水掘削注入
管１を１０ｃｍ程度上昇させスイベルジョイントの切り
替えはそのままにしておき、同じ２０ｌ／分程度で地盤
改良薬液を注入する．この時の注入圧は低いが、地盤に
は先に３方向に亀裂が入っているので、この程度の圧力
でも亀裂が拡大され、上方にも伸びていく．この様な第
２工程を必要回数繰り返えすと、亀裂はどんどん上方に
伸び、その亀裂に沿って地盤改良薬液が注入され、その
亀裂が拡張されて連続した断面三つ葉形柱を形成され
る．After the first step is completed, the anhydrous excavation injection pipe 1 is raised by about 10 cm, the switching of the swivel joint is kept as it is, and the ground improvement chemical is injected at the same rate of about 20 l / min. The injection pressure at this time is low, but the ground has cracks in three directions first, so even with such pressure, the cracks expand and extend upward. When such a second step is repeated as many times as necessary, the crack grows steadily upward, and the ground improvement chemical is injected along the crack, and the crack is expanded to form a continuous trilobal column in cross section.
【００１２】この様に地表に対して略垂直な方向に断面
三つ葉形柱を地盤中に規則的にまたはランダムに複数本
形成することにより、既存の地盤は周囲から押圧されて
圧密化され強化されるうえに、形成された断面三つ葉形
柱が地盤中に散在して強固な地盤が形成され、地盤が液
状化したり土砂崩れしたりしなくなる。As described above, by forming a plurality of three-lobed pillars in the ground in a direction substantially perpendicular to the ground surface, regularly or randomly, the existing ground is pressed from the surroundings to be consolidated and strengthened. In addition, the formed trefoil-shaped columns are scattered in the ground to form a solid ground, and the ground does not liquefy or landslide.
【００１３】次ぎに、請求項２に記載された発明の１実
施例を図３により説明する．図３は、地表に垂直な連続
した断面三つ葉形柱が形成されている地盤を、地表に平
行な面で切断した断面図である．図における１は無水掘
削注入管であり、その周りには断面三つ葉形柱が地表に
垂直な方向に規則的に形成されており、しかも、その突
出部分が繋がるように形成されているものを示してい
る．この様に、断面三つ葉形柱を断面ハニカム構造にす
ることにより、該柱群が相互作用により強化されると共
に、それに囲まれている地盤も均一に圧密されて強化さ
れるので、極めて強固な地盤となる．Next, one embodiment of the invention described in claim 2 will be described with reference to FIG. Fig. 3 is a cross-sectional view of the ground on which a continuous trefoil column having a continuous cross section perpendicular to the ground surface is cut along a plane parallel to the ground surface. In the figure, reference numeral 1 denotes an anhydrous excavation injection pipe, around which a trefoil column having a cross-section is formed regularly in a direction perpendicular to the surface of the earth, and furthermore, the protruding portion is formed so as to be connected. ing. As described above, by forming the three-lobed column in the honeycomb structure, the column group is strengthened by the interaction, and the ground surrounded by the column group is uniformly consolidated and strengthened. Becomes
【００１４】図２、図３では、極めて規則正しい断面三
つ葉形柱及びそれによるハニカム構造が示されている
が、これは理想状態を模擬的に示したものである．現実
には、高圧水による地中に形成される亀裂の方向は、地
盤の楕造などにより不規則な方向に生じるものであり、
３つの亀裂の方向が均等に１２０度ずれていることは極
めて希で、亀裂の角度や深さがランダムで、亀裂が途中
で曲がったりする事が多い．場合によっては、亀裂が２
つしか出来なかったり、４つ、５つ出来たりすることも
ある．したがって、亀裂に侵入して作られる地盤改良薬
液による断面三つ葉形柱柱状物は、その三つ葉の方向
が、不規則に歪んで形成されることが普通である．FIGS. 2 and 3 show a three-lobed column having a very regular cross section and a honeycomb structure formed thereby, which simulates an ideal state. In reality, the direction of cracks formed in the ground by high-pressure water occurs in irregular directions due to the oval shape of the ground,
It is extremely rare that the directions of the three cracks are evenly shifted by 120 degrees, the angles and depths of the cracks are random, and the cracks often bend on the way. In some cases, two cracks
Sometimes you can do only one, or you can do four, five. Therefore, a trefoil-shaped columnar column made of a soil improvement chemical formed by invading a crack is usually formed with irregularly distorted trefoil directions.
【００１５】また、図３では、極めて規則正しい断面三
つ葉形柱によるハニカム構造が示されているが、これも
理想状態を模擬的に示したものであって 現実には、歪
んだものとなるし、断面三つ葉形の突出部分部がすべて
が連設したものとはならないことが多いが、その様なも
のでも、本願発明に含まれるものである．Further, FIG. 3 shows a honeycomb structure formed by three-lobed columns having a very regular cross section. However, this is also a simulated ideal state, and in reality, it is distorted. It is often the case that not all the protruding portions having a three-lobe cross section are continuously provided, but such a case is also included in the present invention.
【００１６】以上に示した実施例では、断面三つ葉形柱
の形成による地盤改良工法について述べたが、改良柱の
断面形状については十字形、星形などがあるが、それは
注入管の噴射方向によって自由に決められる．しかし、
実際には、断面三つ葉形柱が最も良い．また、断面網目
状の形状についても、ハニ カム形状の他、三角形やそ
の他の形状が考えられる．In the above-described embodiment, the ground improvement method by forming a three-lobed column is described. However, the cross-sectional shape of the improved column includes a cross shape and a star shape, which depends on the injection direction of the injection pipe. You can decide freely. But,
In practice, a trefoil column is best. Also, regarding the cross-sectional network shape, a triangle shape or other shapes can be considered in addition to the honeycomb shape.
【００１７】[0017]
【効果】請求項１の発明によれば、次のような効果が得
られる． １、この様な連続した断面ヒトデ形柱を地盤中に形成す
る事により、既存の地盤が周囲から押されて圧密される
ことにより強化されるし、形成された断面ヒトデ形柱が
地盤中に散在するので、地盤が液状化したり土砂崩れし
たりしなくなる． ２、少ない地盤改良薬液で強い地盤が得られる。 ３、スライムの吹出しがないので、スライム廃棄に問題
が生じない． ４、薬液注入による地盤***もほとんどない。 ５、既存の無水掘削注入管が利用できるので、設備費が
安くなる ６、簡単な工法であるから、トラブルが少なく、効率が
良い．According to the first aspect of the invention, the following effects can be obtained. 1. By forming such a continuous starfish-shaped column in the ground, the existing ground is strengthened by being pressed from the surroundings and consolidating, and the formed starfish-shaped column in the ground Because it is scattered, the ground does not liquefy or landslide. 2. Strong ground can be obtained with a small amount of ground improvement chemicals. 3. There is no slime blowing, so there is no problem in slime disposal. 4. There is almost no ground uplift due to chemical injection. 5. Since the existing anhydrous drilling and injection pipe can be used, the equipment cost is low.
【００１８】請求項２の発明によれば、上記１〜６に記
載の効果の他に，次ぎの効果がえられる．断面ヒトデ形
柱を断面網目状構造にすることにより、該柱群が相互作
用により強化されると共に、それに囲まれている地盤も
均一に圧密されて強化されるので、極めて 強固な地盤
となる．According to the second aspect of the invention, the following effects can be obtained in addition to the effects described in the first to sixth aspects. By making the cross-section starfish-shaped column into a cross-sectional network structure, the column group is strengthened by the interaction and the ground surrounded by it is also uniformly consolidated and strengthened, resulting in an extremely strong ground.
【００１９】[0019]
【図１】は、本願発明の工法を説明するための全体図で
ある．FIG. 1 is an overall view for explaining a method of the present invention.
【図２】は、本願発明の工法による断面ヒトデ形柱の１
例としての断面三つ葉形柱が形成されている地盤の一部
を、地表に平行な面で切断した断面図である．FIG. 2 is a cross-sectional starfish-shaped column 1 by the method of the present invention.
This is a cross-sectional view of a part of the ground on which a trilobular column as an example is formed, cut along a plane parallel to the ground surface.
【図３】は、本願発明の工法による断面ヒトデ形柱の１
例としての断面三つ葉形柱が互いに連設してハニカム状
に形成されている地盤の一部を、地表に平行な面で切断
した断面図である。FIG. 3 is a cross-sectional starfish-shaped column 1 by the method of the present invention.
FIG. 3 is a cross-sectional view of a part of the ground in which three-lobed pillars as an example are connected to each other and formed in a honeycomb shape, in a plane parallel to the ground surface.
【００２０】[0020]
１・・・無水掘削注入管 ２・・・作業機 Ｃ・・・断面ヒトデ形柱 １０・・・地盤改良薬液供給装置 ２０・・・水供給装置 DESCRIPTION OF SYMBOLS 1 ... Anhydro excavation injection pipe 2 ... Work machine C ... Cross section starfish-shaped column 10 ... Ground improvement chemical liquid supply apparatus 20 ... Water supply apparatus
Claims (2)
を地盤改良薬液で孔埋めした所を再び無水削孔法により
所定深さまで孔を掘り進め、掘り進めた状態のまま掘削
注入管から高圧で水を複数方向に噴射し、その水が複数
方向に飛び散ることにより地中に複数の亀裂を生じさせ
た後、該堀削注入管から地盤改良薬液を注入してこの複
数の亀裂中にそれを拡張しながら侵入させて断面ヒトデ
形の地盤改良柱を作る第１工程と、掘削注入管を所定量
上昇させた後、再び該掘削注入管から地盤改良薬液を注
入し、先に形成されている断面ヒトデ形の地盤改良柱に
連続して断面ヒトデ形の地盤改良柱を作る第２工程を行
い、この第２工程を繰り返して連続した断面ヒトデ形柱
を地盤中に形成することによる地盤改良工法．1. A place where a hole drilled by an anhydrous drilling method or a hole drilled with water is filled with a ground improvement chemical solution, the hole is dug again to a predetermined depth by an anhydrous drilling method, and excavation and injection are performed while the drilling is continued. Water is injected from the pipe at high pressure in a plurality of directions, and the water scatters in the plurality of directions to cause a plurality of cracks in the ground. A first step of making a soil improvement column having a starfish cross-section by invading it while expanding it, and after raising a drilling injection pipe by a predetermined amount, injecting a ground improvement chemical solution again from the drilling injection pipe, Performing a second step of forming a starfish-shaped ground improvement column in cross-section continuously with the formed starfish-shaped ground improvement column, and forming a continuous cross-section starfish-shaped column in the ground by repeating the second step; Ground improvement method by using.
を地盤改良薬液で孔埋めした所を再び無水削孔法により
所定深さまで孔を掘り進め、掘り進めた状態で掘削注入
管から高圧で水を複数方向に噴射し、その水が複数方向
に飛び散ることにより地中に複数の亀裂を生じさせた
後、該堀削注入管から地盤改良薬液を注入してこの複数
の亀裂中にそれを拡張しながら侵入させて断面ヒトデ形
の地盤改良柱を作る第１工程と、掘削注入管を所定量上
昇させた後、再び該掘削注入管から地盤改良薬液を注入
し、先に形成されている断面ヒトデ形の地盤改良柱に連
続して断面ヒトデ形の地盤改良柱を作る第２工程を行
い、この第２工程を繰り返して連続した断面ヒトデ形柱
を形成し、上記第１工程と第２工程とを近接した複数箇
所で行うことにより、隣接した断面ヒトデ形の地盤改良
柱の軸心に沿った突出部分同志が互いに繋がるようにし
た断面網目状構造の地盤改良柱を形成することによる地
盤改良工法。2. A hole drilled by an anhydrous drilling method or a hole drilled to a predetermined depth by an anhydrous drilling method at a place where a hole drilled with water is filled with a ground improvement chemical solution. Injects water in multiple directions at high pressure from the water and creates multiple cracks in the ground by splashing the water in multiple directions. A first step of making a soil-improved pillar having a starfish-shaped cross-section by invading it while expanding it, and after raising the excavated injection pipe by a predetermined amount, injecting the soil-improving chemical again from the excavated injection pipe to form first Performing a second step of forming a starfish-shaped cross-section ground improvement column continuously with the cross-sectional starfish-shaped ground improvement column, and repeating the second step to form a continuous cross-section starfish-shaped column; And the second step are performed at a plurality of adjacent locations, so that A ground improvement method by forming a ground improvement pillar having a mesh-like cross section in which protruding portions along the axis of a contacted starfish shaped soil improvement pillar are connected to each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14933795A JP2799554B2 (en) | 1995-05-15 | 1995-05-15 | Ground improvement method by forming starfish shaped column |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14933795A JP2799554B2 (en) | 1995-05-15 | 1995-05-15 | Ground improvement method by forming starfish shaped column |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08311858A JPH08311858A (en) | 1996-11-26 |
| JP2799554B2 true JP2799554B2 (en) | 1998-09-17 |
Family
ID=15472905
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14933795A Expired - Lifetime JP2799554B2 (en) | 1995-05-15 | 1995-05-15 | Ground improvement method by forming starfish shaped column |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2799554B2 (en) |
-
1995
- 1995-05-15 JP JP14933795A patent/JP2799554B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08311858A (en) | 1996-11-26 |
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