JPH07111052B2 - Ground improvement or strengthening method - Google Patents
Ground improvement or strengthening methodInfo
- Publication number
- JPH07111052B2 JPH07111052B2 JP3129473A JP12947391A JPH07111052B2 JP H07111052 B2 JPH07111052 B2 JP H07111052B2 JP 3129473 A JP3129473 A JP 3129473A JP 12947391 A JP12947391 A JP 12947391A JP H07111052 B2 JPH07111052 B2 JP H07111052B2
- Authority
- JP
- Japan
- Prior art keywords
- ground
- mud
- improving
- self
- strengthening
- 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 - Fee Related
Links
Description
【０００１】[0001]
【産業上の利用分野】本発明は、軟弱地盤の改良または
強化工法に係り、特に一旦緩ませた地盤中に粘度の高い
セメント系などの自硬性材料をいわば押し込むように圧
入することにより改良を図る工法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement or strengthening method for soft ground, and in particular, it is improved by press-fitting a self-hardening material such as cement having a high viscosity into the once loosened ground. Regarding the construction method.
【０００２】[0002]
【従来の技術】この種の地盤改良工法としては、種々の
ものが知られている。その代表例は、薬液注入工法であ
る。この工法は、周知のように、地盤中に挿入した注入
管により低圧で薬液を注入するものである。また、この
場合、薬液を地盤を乱すことなく、浸透圧入させること
を基本思想としている。2. Description of the Related Art Various types of ground improvement methods are known. A typical example is the chemical injection method. As is well known, this construction method is to inject a chemical liquid at a low pressure through an injection pipe inserted into the ground. Further, in this case, the basic idea is to osmotically press the chemical liquid without disturbing the ground.
【０００３】他方で、近年、いわゆるジェットグラウト
工法に代表される高圧噴射工法が多く用いられるように
なってきた。この高圧噴射工法は、地盤をグラウトまた
は水のもつ高圧力により乱しながら同時に地盤中にグラ
ウトを注入するものである。この高圧噴射工法は、極端
にいえば地盤の攪拌工法とも言える。他方、純粋な攪拌
工法としては、主に粘性地盤を対象にし、攪拌羽根を有
する攪拌軸を地盤に挿入した状態で、その攪拌軸を通し
てまたは別途の供給系統からセメント系材料を供給し、
攪拌羽根により地盤を攪拌しながらその攪拌領域をセメ
ント系材料により置換または土砂と攪拌混合するもので
ある。On the other hand, in recent years, a high-pressure injection method represented by a so-called jet grout method has been widely used. This high-pressure injection method is to inject the grout into the ground while disturbing the ground by the high pressure of the grout or water. This high-pressure injection method can be said to be a ground agitation method in extreme terms. On the other hand, as a pure stirring method, mainly for viscous ground, with a stirring shaft having stirring blades inserted in the ground, supply the cement material through the stirring shaft or from a separate supply system,
While stirring the ground with stirring blades, the stirring area is replaced with a cement material or stirred and mixed with earth and sand.
【０００４】[0004]
【発明が解決しようとする課題】しかし、第１の薬液圧
入工法では、浸透圧入を行うために、粘度の低い材料、
主として水ガラス系の材料を用いるので、改良強度は低
いとともに、耐久性に乏しい。さらに、改良強度が低い
理由は、地盤を改良材により置換するのではなく浸透注
入または割裂注入することをもって良しとするので、単
位容積当たりの改良材の占める割合が低く不均一なこと
にも起因している。However, in the first chemical solution press-fitting method, in order to perform the osmotic press-fitting, a material having a low viscosity,
Since mainly water glass materials are used, the improvement strength is low and the durability is poor. Furthermore, the reason why the improvement strength is low is that it is better to inject or split the ground instead of replacing it with the improvement material, so it is also because the proportion of the improvement material per unit volume is low and uneven. is doing.
【０００５】さらに問題点を付言すれば、通常砂質土層
の場合には、浸透注入を行うことができるが、注入条件
のわずかな差異により割裂注入の形態となり、浸透注入
を行うことができないことが多々ある。他方、粘性土層
に注入する場合、割裂注入となり、改良材が逸走するこ
とが多い。このために、目的の領域のみを確実に改良す
ることが困難であり、しかも逸走に伴う材料ロスが多
い。また、目的の改良径は均一にできず、トリー状（樹
木状あるいは脈状）になることが多い。In addition to the problems mentioned above, in the case of a normal sandy soil layer, osmotic injection can be performed, but due to a slight difference in the injection conditions, split injection is performed and infiltration injection cannot be performed. There are many things. On the other hand, when injecting into the cohesive soil layer, split injection often occurs and the improved material often escapes. For this reason, it is difficult to surely improve only the target region, and moreover, there is much material loss due to the escape. Further, the target improved diameter cannot be made uniform, and often has a tree shape (tree shape or vein shape).
【０００６】第２の高圧噴射工法では、地盤を極端に乱
し、かつスライム（泥水）処理に多大な手間と費用を要
する。さらに、切削および注入を均一に行おうとすれ
ば、そしてスライムの排出を充分に行おうとすれば、改
良速度を低下させる必要があり、時間がかかる工法であ
る。しかも、砂質地盤に対しては、強度として３０kg／
cm2 以上、粘性地盤の場合には１０kg／cm2 以上を目標
にするが、地盤性状による強度のばらつきおよび改良体
の位置による強度のばらつきが極めて大きいことが問題
である。特に、粘性土地盤の場合、切削不十分なことに
よる土塊の抱き込みによるばらつきが大きい。In the second high-pressure injection method, the ground is extremely disturbed, and the slime (muddy water) treatment requires a great deal of labor and cost. Furthermore, if cutting and pouring are to be performed uniformly, and if slime is to be discharged sufficiently, it is necessary to reduce the improvement rate, which is a time-consuming method. Moreover, for sandy ground, the strength is 30 kg /
cm 2 or more, in the case of viscous soil is to target a 10 kg / cm 2 or more, the variation in intensity due to the position variation and improvement of strength due to geological nature is extremely large problem. In particular, in the case of cohesive ground, there are large variations due to the inclusion of soil clods due to insufficient cutting.
【０００７】第３の攪拌工法は、設備が大型化すること
が大きな欠点であり、かつ粘性土層の場合、土粒子と改
良材との混合物が攪拌羽根に共回りしてしまい、攪拌効
果がさほど高くなく、もって改良強度の均一性に欠け
る。他方、この攪拌工法は、前述のように粘性地盤を対
象にする。砂質地盤への適用も不可能ではないが、攪拌
軸および攪拌羽根の地盤に対する抵抗が大きいので、巨
大な攪拌手段を用いない限り適用することができない。The third agitation method has a major drawback in that the equipment is large, and in the case of a cohesive soil layer, a mixture of soil particles and an improving material co-rotates with the agitation blade, resulting in an agitation effect. It is not so high and thus lacks uniformity of improved strength. On the other hand, this stirring method targets the viscous ground as described above. It is not impossible to apply it to sandy ground, but since the resistance of the stirring shaft and stirring blades to the ground is large, it cannot be applied unless a huge stirring means is used.
【０００８】したがって、本発明の主たる課題は、改良
強度および改良体の均一性を高めること、簡単なかつ小
型の設備により施工を行うことができるようにするこ
と、圧密効果により限定されたまたは目的の個所のみに
強固な改良体を造成することにある。[0008] Therefore, the main object of the present invention is to improve the improved strength and uniformity of the improved body, to be able to carry out the construction with a simple and small-sized equipment, and to be limited by the consolidation effect or to achieve the object. It is to create a strong improved body only at the points.
【０００９】上記課題は、地盤中に挿入した噴射管の先
端部に設けた高圧液噴射ノズルから高圧水を噴射して対
象地盤を緩めて泥土化し、次いでこの緩んだ地盤中に高
粘性の自硬性材料を圧入することにより、前記弛緩泥土
を押し上げて排除するとともに前記自硬性材料による置
換を行い改良体を造成することで解決できる。The above-mentioned problem is to inject high-pressure water from a high-pressure liquid injection nozzle provided at the tip of an injection pipe inserted into the ground to loosen the target ground to make it mud, and then to raise it in the loose ground.
By pressing in a viscous self-hardening material, the relaxing mud
And push it up to remove it and place it with the self-hardening material.
It is possible to solve it by substituting it and creating an improved body.
【００１０】また、この場合、高圧液により地盤を緩め
る時点と、自硬性材料の圧入時点とが異なるせることも
できるし、噴射注入管の先端部に注出口を形成し、この
注出口より基端側に噴射ノズルを設け、噴射注入管の引
上げ過程で地盤の弛緩と自硬性材料の圧入とをほぼ同時
に行うこともできる。高圧液噴射ノズルからの高圧液の
噴射圧力が５０kg／cm2 Ｇ以上とすることができる。地
盤を緩める液は、水に界面活性剤を添加すると切削能力
が高まる。排除された泥土に自硬性材料を添加して改良
体の造成材料とすることができる。排除された泥土を上
澄液と濃縮泥土とに分離し、前記上澄液は地盤の弛緩用
の液としてそのまま又は水に添加して再利用することが
好ましい。前記濃縮泥土は自硬性材料に添加して改良体
の造成材料として再利用することができる。一方、噴射
管は２つの流路を有し、その一方の流路を地盤の弛緩用
液の供給に用い、他方の流路を穿孔時における削孔水の
供給および地盤弛緩後の自硬性材料の供給に用いること
ができる。噴射管が３つの流路を有する場合には、その
第１の流路を地盤の弛緩用液の供給に用い、第２の流路
を弛緩用液による地盤の切削能力向上および泥土の地上
へのエアリフトを行う圧縮空気の供給に用い、第３の流
路を地盤弛緩後の自硬性材料の供給に用いることができ
る。Further, in this case, the time when the ground is loosened by the high-pressure liquid can be different from the time when the self-hardening material is pressed in, and a spout is formed at the tip of the injection injection pipe, and a base is formed from this spout. It is also possible to provide an injection nozzle on the end side and to relax the ground and press-fit the self-hardening material almost at the same time in the process of pulling up the injection injection pipe. The injection pressure of the high-pressure liquid from the high-pressure liquid injection nozzle can be set to 50 kg / cm 2 G or more. The liquid that loosens the ground enhances its cutting ability when a surfactant is added to water. As possible out to the reclamation material for improved body by adding self-hardening material in the excluded mud. It is preferable that the removed mud is separated into a supernatant and a concentrated mud, and the supernatant is reused as it is as a soil relaxation liquid or added to water for reuse. The concentrated mud can be added to a self-hardening material and reused as a material for forming an improved body. On the other hand, the injection pipe has two flow passages, one of which is used for supplying the relaxation liquid for the ground, and the other flow passage is used for supplying drilling water during drilling and self-hardening material after the relaxation of the ground. Can be used to supply When the injection pipe has three flow paths, the first flow path is used to supply the relaxation liquid for the ground, and the second flow path is used to improve the cutting ability of the ground by the relaxation liquid and to the surface of the mud. The third flow path can be used to supply the self-hardening material after the soil relaxation, and can be used to supply the compressed air for performing the air lift.
【００１１】改良対象域に鉄筋類を挿入して改良体中に
埋設すれば、杭または壁とすることができる。一つの改
良体を連設すれば、柱列杭または柱列壁を造成できる。If reinforcing bars are inserted in the area to be improved and embedded in the improved body, the pile or wall can be obtained. By arranging one improvement body in series, a pillar row pile or a pillar row wall can be constructed.
【００１２】[0012]
【作用】本発明は、「一旦地盤を緩めた後、その緩んだ
部分に圧入すると、たとえばジェットグラウト工法のよ
うに地盤の攪拌と注入とを同時に行いかつ単位水量の多
い流動性の高い注入剤を用いる場合に比較して、圧密の
範囲が拡大しかつ改良後の強度が高まる」との知見に基
礎を置いている。According to the present invention, "Once the ground is loosened and then press-fitted into the loosened part, the ground is agitated and poured at the same time as in the jet grout method, and the fluidity is high and the fluidity is high. The range of consolidation is expanded and the strength after improvement is increased compared to the case of using.
【００１３】本発明にしたがって高圧水を噴射すると、
対象地盤を緩めることができる。地盤の弛緩は、主に大
きな土粒子とこれらの土粒子間を繋いでいるその周りの
細かい土粒子との接合が分断されることにより行われ
る。また、この分断により空隙部分の割合が多くなり、
続く改良材の圧入の道が形成される。When high-pressure water is jetted according to the present invention,
The target ground can be loosened. The loosening of the ground is mainly performed by breaking the junction between large soil particles and the fine soil particles around them that connect these soil particles. In addition, the ratio of voids increases due to this division,
A passage for the subsequent press-in of the modifying material is formed.
【００１４】この緩んだ対象地盤に対して、スランプ値
が小さい改良材（自硬性材料）を圧入すると、地盤の緩
んだ部分に改良材が押し込まれるように圧入される。こ
の圧入により、緩んだ地盤を押し広げるように改良材が
注入される。このとき、改良材のスランプ値が小さいの
で、改良材の逸走が防止されるとともに、緩んだ地盤部
分が改良材により置換され、あたかもその地盤部分が改
良材により充填されるようになる。さらに、改良材の押
し込み圧力により、地盤部分が圧密されるとともに、軟
弱な部分には多くの改良材が圧入される一方で、強度の
高い部分に対しては、地盤の緩み度合いが少ないので、
改良材の圧入量が少なく圧入され、もって全体としては
均一な強度をもったかつ均一な改良径の改良体を造成で
きる。When the improvement material (self-hardening material) having a small slump value is press-fitted into the loose target ground, the improvement material is pressed into the loosened portion of the ground. By this press-fitting, the improvement material is injected so as to spread the loose ground. At this time, since the slump value of the improvement material is small, the escape of the improvement material is prevented, the loose ground portion is replaced by the improvement material, and the ground portion is filled with the improvement material. Furthermore, due to the pushing pressure of the improving material, the ground portion is consolidated, and while many improving materials are pressed into the soft portion, the degree of looseness of the ground is small for the high-strength portion,
A small amount of the improved material is press-fitted, so that it is possible to form an improved body having uniform strength and uniform improved diameter as a whole.
【００１５】他方、用いる設備として、細い管たとえば
70mm程度のものを用いることで充分に対応できるので、
設備費が高圧噴射工法や攪拌工法に比較して、低廉とな
る。On the other hand, as equipment to be used, a thin pipe such as
Since it can be sufficiently supported by using a 70 mm thing,
The equipment cost is lower than that of the high-pressure injection method and the stirring method.
【００１６】しかも、地盤を緩めるのに高圧水を用いる
ので、スライムとしては、高圧噴射工法にみられるよう
にセメントと土粒子との混合スライムでなく、水と土粒
子との混合物であるので、スライム処理が容易である利
点がある。また、砂質地盤に対しても本発明を容易に適
用でき、この点、従来の攪拌工法と顕著な相違がある。
しかも、地盤の対象域の緩め化と改良材の圧入とを別工
程または別ステージで行うので、高圧噴射工法にみられ
る改良強度のばらつきがなくなる。Moreover, since high-pressure water is used to loosen the ground, the slime is not a mixed slime of cement and soil particles as seen in the high-pressure injection method, but a mixture of water and soil particles. There is an advantage that slime treatment is easy. Further, the present invention can be easily applied to sandy ground, and in this respect, there is a significant difference from the conventional stirring method.
Moreover, the loosening of the target area of the ground and the press-fitting of the improvement material are performed in separate steps or stages, so that there is no variation in the improvement strength found in the high-pressure injection method.
【００１７】[0017]
【実施例】以下本発明を図面を参照しながら具体例を挙
げてさらに詳説する。図１〜図４は第１の具体例で、図
１に示すように、先端部にノズル１を有する噴射管２を
地盤中にある深度まで挿入し、その後、図２に示すよう
に、この噴射管２を回転しながら引き上げる過程で、前
記噴射ノズル１から高圧水Ｗを地盤の性状（土質、軟弱
度など）や目的の改良径に対応した圧力、好ましくは一
般的に５０kg／cm2 以上の圧力、特に好ましくは80〜35
0 kg／cm2 の圧力をもって噴射して対象地盤を緩める。
この緩んだ地盤部分を符号Ｓで示す。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to specific examples with reference to the drawings. 1 to 4 show a first specific example, as shown in FIG. 1, an injection pipe 2 having a nozzle 1 at its tip is inserted to a certain depth in the ground, and thereafter, as shown in FIG. In the process of pulling up the jet pipe 2 while rotating, the high pressure water W is jetted from the jet nozzle 1 at a pressure corresponding to the properties of the ground (soil, softness, etc.) and the target improved diameter, preferably 50 kg / cm 2 or more. Pressure, particularly preferably 80-35
Loosen the target ground by spraying with a pressure of 0 kg / cm 2 .
This loose ground portion is indicated by a symbol S.
【００１８】次いで、この工程が終了したならば、図３
のように、緩んだ対象部分に圧入管２Ａを挿入し、たと
えばその先端から、スランプ値（ＪＩＳ Ａ １１０
１）が５以上、より好ましくは８以上の自硬性改良材Ｇ
を流し込んで、図４のように改良体を造成する。Then, when this step is completed, FIG.
As described above, the press-fitting pipe 2A is inserted into the loose target portion, and the slump value (JIS A 110
1) is 5 or more, more preferably 8 or more self-hardening material G
Then, the improved body is formed as shown in FIG.
【００１９】改良材Ｇを圧入するときのその態様を図５
および図６に示した。図６における〜は経時を示
す。これらの図面からも、本発明の改良材を圧入する場
合には、クリーム状に圧入されることが判明するであろ
う。FIG. 5 shows the manner in which the improvement material G is press-fitted.
And shown in FIG. 6 in FIG. 6 indicates the time. From these drawings, it will be clear that when the improvement material of the present invention is press-fitted, it is pressed-in like a cream.
【００２０】本発明において、改良材としては、セメン
トモルタル系、セメント粘土系、石灰系などの自硬性の
あるものが用いることができ、前述のように粘度が高い
ものが用いられる。このうち最も好ましいのはセメント
モルタル系のもので、これに微粒子スラグ、ベントナイ
トなどの他の無機材料、発泡剤、気泡剤、分離防止剤、
減水剤などの各種添加剤などを添加することができる。
さらに、水ガラスやその硬化剤をある割合で添加するこ
ともできる。In the present invention, as the improving material, a self-hardening material such as cement mortar type, cement clay type or lime type can be used, and as mentioned above, a material having a high viscosity is used. Of these, the most preferable are cement mortar-based ones, in which fine particle slag, other inorganic materials such as bentonite, foaming agents, foaming agents, separation preventing agents,
Various additives such as a water reducing agent can be added.
Further, water glass and its curing agent can be added in a certain ratio.
【００２１】第１の具体例は、噴射管２と圧入管２Ａと
を別個に用いる例であるが、第２の具体例として示す図
７のように、内管２１と外管２２とを有する同心２重管
からなる噴射管２０を用い、まずその噴射管２０に回転
力と押し込み力を作用させつつその先端の切削ビット２
３により地盤を切削しながら、所定深度まで噴射管２０
を地盤中に挿入する。The first specific example is an example in which the injection pipe 2 and the press-fitting pipe 2A are separately used, but as shown in FIG. 7 showing the second specific example, an inner pipe 21 and an outer pipe 22 are provided. The injection pipe 20 formed of a concentric double pipe is used, and first, the cutting bit 2 at the tip of the injection pipe 20 is exerted while exerting a rotational force and a pushing force.
While cutting the ground by 3, the injection pipe 20 to a predetermined depth
Insert into the ground.
【００２２】次にこの噴射管２０を回転しながら引き上
げる過程で、先端より基部側周壁に設けた噴射ノズル２
４から高圧水を噴射し、地盤の対象域を緩める。同時に
先端に開口する注出口２５から前記の改良材Ｇを圧入す
る。Next, in the process of pulling up the injection pipe 20 while rotating it, the injection nozzle 2 provided on the peripheral wall of the base side from the tip end.
Inject high-pressure water from 4 to loosen the target area of the ground. At the same time, the above-mentioned improvement material G is press-fitted from the spout 25 opening at the tip.
【００２３】なお、２６は内管２１と外管２２との間隙
を塞ぐプラグである。Reference numeral 26 is a plug that closes the gap between the inner pipe 21 and the outer pipe 22.
【００２４】図７を参照しながら圧密態様を概念的な説
明を行うと、改良材Ｇの注入により、一旦地盤の緩んだ
部分に改良材Ｇが充満したのちに、圧入を続行すると、
後の改良材が先に吐出された改良材を外方に押し込むよ
うに作用し、結果として第７図のように、周囲に改良材
の圧密部分Ｚ1 を、中心部分に固結体Ｚ2 をもった改良
体を造成できる。When the consolidation mode is conceptually explained with reference to FIG. 7, the improvement material G is injected to fill the loosened part of the ground with the improvement material G, and then the press-fitting is continued.
The later improving material acts so as to push the previously discharged improving material outwardly, and as a result, as shown in FIG. 7, a consolidated portion Z 1 of the improving material is provided around the solidified body Z 2 at the central portion. You can create an improved body with.
【００２５】一方、第２の具体例のように、２重管また
は複流路管を用いる場合、噴射管を挿入させる過程で高
圧水を噴射して地盤を緩めることができる。この下降過
程で地盤を緩めることは、第１の具体例においても適用
できる。On the other hand, when the double pipe or the multi-passage pipe is used as in the second embodiment, the ground can be loosened by injecting high pressure water in the process of inserting the injection pipe. The loosening of the ground in this descending process can be applied to the first specific example.
【００２６】一方、前記各例は連続的な改良体を造成す
る例であるが、図８のように、間欠的な改良ステージを
造成することもできる。この場合は、枝状骨格により地
盤全体を強化させることを意図するものである。On the other hand, although each of the above examples is an example of forming a continuous improvement body, it is also possible to form an intermittent improvement stage as shown in FIG. In this case, it is intended to strengthen the whole ground by the branch-like skeleton.
【００２７】本発明において、高圧水の圧力としては、
通常圧入管近傍にまたは注入ポンプの出側に設けられる
ゲージの圧力をいう。この圧力としては、前述のように
５０kg／cm2 以上とするのが好ましいが、場合により１
００kg／cm2 以上とすることが好ましいことがある。噴
射水量としては、５〜１５リットル／分が望ましい。In the present invention, the pressure of the high pressure water is
It usually refers to the pressure of a gauge provided near the press-in pipe or on the outlet side of the infusion pump. It is preferable that the pressure is 50 kg / cm 2 or more as described above, but in some cases 1
It may be preferable to set it to be not less than 00 kg / cm 2 . The amount of water sprayed is preferably 5 to 15 liters / minute.
【００２８】本発明における噴射管としては、通常外径
が８０mm以下のもので足りる。圧入管についても同様で
ある。圧入にあたり、ホース類など用いることができ
る。As the injection pipe in the present invention, one having an outer diameter of 80 mm or less is usually sufficient. The same applies to the press fitting pipe. Hoses and the like can be used for press fitting.
【００２９】本発明は、各種の工事に適用できる。たと
えば図９のように、軌道３１路盤における土砂部分３０
の強化や、図１０のように、コンクリート構造物４０の
下方に軟弱部分の改良などを挙げることができる。３２
はバラストである。The present invention can be applied to various works. For example, as shown in FIG. 9, the earth and sand portion 30 on the track 31 roadbed
And the improvement of the soft portion below the concrete structure 40 as shown in FIG. 32
Is a ballast.
【００３０】一方、地盤を弛緩させる高圧液としては、
水を用いるのが入手の容易性およびコストの点が好まし
いが、水に界面活性剤を添加すると、地盤に対する切削
性が高まる。また、弛緩によって生成した泥土を、上澄
液と濃縮泥土とに分離したのち、その上澄液を用いるこ
とができる。たとえば、図１１に示すように、高圧噴射
管２０の口元に泥土ピット５０を設けて、改良材Ｇによ
る置換に伴って、高圧噴射管２０と孔壁との間を上昇し
た泥土５１をポンプ５２により汲み上げて、分離装置５
３により上澄液５１Ａと濃縮泥土５１Ｂとに分離し、そ
の上澄液５１Ａはポンプ５４により、供給する高圧水Ｗ
に添加して、あるいは泥土の水分が多い場合には、上澄
液５１Ａのみを供給して、地盤の切削に用いることがで
きる。他方、濃縮泥土５１Ｂはホッパー５５を介して、
ミキシングドラム５６に供給し、そこにおいて改良材Ｇ
と混合させた後、ポンプ５７により高圧噴射管２０に充
填または置換用の改良材として供給することができる。
このように、上澄液を切削用に利用すると、小さな粒子
分を含んでいるので、切削性が良好である。また、濃縮
泥土を再利用すると、泥水処理がその分低減する。な
お、泥土５１を処理することなく、そのまま改良材Ｇに
添加することもできる。On the other hand, as a high-pressure liquid for relaxing the ground,
It is preferable to use water in terms of availability and cost, but when a surfactant is added to water, the machinability of the ground is improved. Further, after the mud produced by relaxation is separated into a supernatant and a concentrated mud, the supernatant can be used. For example, as shown in FIG. 11, a mud pit 50 is provided at the mouth of the high-pressure injection pipe 20, and the mud 51 that has risen between the high-pressure injection pipe 20 and the hole wall is pumped 52 with the replacement with the improvement material G. Pumped by the separation device 5
3 separates the supernatant 51A and the concentrated mud 51B, and the supernatant 51A is supplied by the pump 54 to the high-pressure water W
Or when the mud has a high water content, only the supernatant liquid 51A can be supplied and used for cutting the ground. On the other hand, the concentrated mud 51B passes through the hopper 55,
It is supplied to the mixing drum 56, where the improvement material G
After being mixed with, it can be supplied to the high-pressure injection pipe 20 by the pump 57 as an improving material for filling or replacing.
As described above, when the supernatant liquid is used for cutting, it contains a small particle content and thus has good cutting properties. In addition, if the concentrated mud is reused, muddy water treatment is reduced accordingly. The muddy soil 51 may be added to the improving material G as it is without being treated.
【００３１】ところで、用いる管としては、前述のよう
に、噴射管２と圧入管２Ａとを別々に用意することな
く、両者の機能をもった単一の管であることが、施工性
に優れる。この場合、たとえば図７に示す２重管の場
合、外管側を地盤の弛緩用の液の供給に用い、内管側を
改良材Ｇの供給とともに、それに先立つ穿孔時において
は、削孔水の供給に用いることができる。By the way, as described above, the pipe to be used is a single pipe having both functions without separately preparing the injection pipe 2 and the press-fitting pipe 2A, which is excellent in workability. . In this case, for example, in the case of the double pipe shown in FIG. 7, the outer pipe side is used for supplying the liquid for relaxing the ground, the inner pipe side is supplied with the improving material G, and the drilling water is used at the time of the preceding drilling. Can be used to supply
【００３２】たとえば図１２に示すような３重管６０を
用いることもできる。この３重管６０は外管６１、中管
６２および内管６３を有し、外壁に噴射ノズル６４を取
付け、その周囲にエアＡの環状吐出口６５を形成したも
のである。狭い環状吐出口６５から圧縮または高圧たと
えば５kg／cm2 以上のエアを吐出させると、泥土５１は
エアリフト効果により円滑に地上に排出されるととも
に、地盤の切削能力が高まる。For example, a triple tube 60 as shown in FIG. 12 can be used. The triple tube 60 has an outer tube 61, a middle tube 62 and an inner tube 63, an injection nozzle 64 is attached to the outer wall, and an annular discharge port 65 for air A is formed around the injection nozzle 64. When compressed or high-pressure air of, for example, 5 kg / cm 2 or more is discharged from the narrow annular discharge port 65, the mud soil 51 is smoothly discharged to the ground due to the air lift effect, and the ground cutting capability is enhanced.
【００３３】改良材Ｇを確実にまたはより圧入させたい
場合、図１３に示すように、改良材Ｇを供給する流路を
蓋体２７により閉塞し、当初流し込みによって行ってい
たまたは低い圧力で圧入を行っていた改良材Ｇをそれ以
上地盤が受付けなくなったとき、高い圧力をもって圧入
させることができる。その際、圧力計２８により圧力を
監視しながら、圧入度合い、換言すれば地盤の圧密度を
制御できる。かかる圧密は、通常、改良材Ｇが数時間以
内で硬化または半硬化するので、その状態以前に行うこ
とが望まれる。When it is desired to press the improving material G more reliably or more tightly, as shown in FIG. 13, the flow path for supplying the improving material G is closed by the lid 27, and press-fitting is carried out at a low pressure which was originally performed by pouring. When the ground no longer accepts the improved material G which has been subjected to the above, it can be pressed in with a high pressure. At this time, the degree of press-fitting, in other words, the pressure density of the ground can be controlled while monitoring the pressure with the pressure gauge 28. Since such consolidation is usually cured or semi-cured within a few hours of the improving material G, it is desirable to perform the consolidation before the state.
【００３４】本発明によれば、強度の高い改良体を得る
ことができるので、強度の高い杭体を造成できる。ま
た、この杭体を連設することで、柱列杭または柱列壁の
造成も行うことができる。この場合、単に改良材のみで
改良体を造成するほか、１本または複数本の鉄筋または
適宜の形状の鋼材（鉄筋類という）を改良体内に挿入す
ることで、その改良体の補強を図るのが好ましい。たと
えば、図１４および図１５に示すように、各改良体Ｚ内
に１本または複数本の鉄筋または適宜の形状の鋼材から
なる鉄筋類７０を埋設するとともに、各改良体Ｚをラッ
プさせることで連設することで造成できる。さらに、鉄
筋類として、改良材の送給に用いた噴射管を地盤中に残
して、これを改良体の補強に用いることもできる。According to the present invention, since an improved body having high strength can be obtained, a pile body having high strength can be formed. In addition, by arranging the piles in series, it is possible to construct a pillar row pile or a pillar row wall. In this case, in addition to constructing the improved body only with the improved material, the improved body is reinforced by inserting one or more reinforcing bars or steel materials (referred to as reinforcing bars) of an appropriate shape into the improved body. Is preferred. For example, as shown in FIGS. 14 and 15, by embedding one or a plurality of rebars or rebars 70 made of a steel material having an appropriate shape in each improved body Z and wrapping each improved body Z with each other. Can be created by arranging them in series. Further, as a reinforcing bar, the injection pipe used for feeding the improvement material may be left in the ground and used for reinforcing the improvement body.
【００３５】一方、本発明は、機械的攪拌混合手段と併
用することができる。たとえば、図１６に示すように、
先端部に切削ビット８２を切削ロッド８０を用いて、所
定深度まで削孔する。もちろん、その過程で好ましくは
切削ビット８２の下方に設けた噴射ノズル８３により周
囲地盤を弛緩させながら、削孔を行う。次いで、図１８
のように、引き上げの過程で、改良材Ｇを自然流下また
は圧入させる。これにより、図１９に示すような改良体
を得ることができる。なお、切削ビット８２の上方に攪
拌羽根をロッド８０に突出して設けることもできる。On the other hand, the present invention can be used in combination with mechanical stirring and mixing means. For example, as shown in FIG.
The cutting bit 82 is drilled to a predetermined depth at the tip portion using the cutting rod 80. Of course, in that process, it is preferable to drill the holes while relaxing the surrounding ground by the injection nozzles 83 provided below the cutting bit 82. Then, FIG.
As described above, in the process of pulling up, the improving material G is naturally flown or press-fitted. Thereby, the improved body as shown in FIG. 19 can be obtained. A stirring blade may be provided above the cutting bit 82 so as to project from the rod 80.
【００３６】（実験例）本発明者らは、ほぼ図７に近似
する噴射管を用いて、砕石粉埋め立て地において改良の
実験を行った。地盤弛緩用液：高圧水（圧力200 kg／cm
2 ）、その噴射量80リットル／分、切削速度：３０分／
ｍ、使用改良材：セメント、ベントナイト、砂のセメン
ト−ベントナイト系モルタルである。一方、比較例とし
て、いわゆるＣＣＰ工法での改良も行った。(Experimental example) The inventors of the present invention conducted an improvement experiment in a crushed stone powder landfill site by using an injection pipe approximately similar to FIG. Ground relaxation liquid: High pressure water (pressure 200 kg / cm
2 ), its injection amount 80 liters / minute, cutting speed: 30 minutes /
m, improver used: cement, bentonite, sand cement-bentonite mortar. On the other hand, as a comparative example, the so-called CCP method was also improved.
【００３７】施工後数日経過して、掘り起こして固結体
の改良状況を観察したところ、本発明例では、図１７お
よび図１８に示す形状であったのに対して、比較例にお
いては、図１９および図２０に示すように改良形状が不
均一なものであった。しかも、固結体内に図示のように
多数の土塊を抱き込んだ状態となり、均一性が悪いもの
であった。これによって、本発明によれば、従来例に比
較して、理想的な形状をもった固結体として改良できる
ことが判明した。After several days had passed after the construction, the state of improvement of the solidified body was observed by digging up, and in the examples of the present invention, the shapes shown in FIGS. 17 and 18 were obtained. As shown in FIGS. 19 and 20, the improved shape was non-uniform. Moreover, as shown in the figure, a large number of clods were held in the solidified body, resulting in poor uniformity. As a result, it has been found that the present invention can be improved as a solid body having an ideal shape as compared with the conventional example.
【００３８】[0038]
【発明の効果】以上の通り、本発明によれば、改良強度
が高まる、簡単なかつ小型の設備により施工を行うこと
ができる、圧密効果により限定されたまたは目的の個所
のみに均一で強固な改良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, improved strength can be improved, construction can be carried out by a simple and small-sized facility, and uniform and strong improvement can be achieved only at a place limited by the consolidation effect or at an intended point. There are advantages such as the ability to build a body.
【図１】第１の具体例を施工順に示した第１の工程の概
要図である。FIG. 1 is a schematic view of a first step showing a first specific example in a construction order.
【図２】第１の具体例を施工順に示した第２の工程の概
要図である。FIG. 2 is a schematic diagram of a second step showing the first specific example in the order of construction.
【図３】第１の具体例を施工順に示した第３の工程の概
要図である。FIG. 3 is a schematic diagram of a third step showing the first specific example in the order of construction.
【図４】第１の具体例を施工順に示した第４の工程の概
要図である。FIG. 4 is a schematic view of a fourth step showing the first specific example in the order of construction.
【図５】改良材の圧入形態の概略図である。FIG. 5 is a schematic view of a press-fitting mode of the improved material.
【図６】改良材の移動過程を示す平面図である。FIG. 6 is a plan view showing the movement process of the improvement material.
【図７】第２の具体例の概要図である。FIG. 7 is a schematic diagram of a second specific example.
【図８】他の改良形態の概要図である。FIG. 8 is a schematic view of another improved mode.
【図９】他の施工例の概要図である。FIG. 9 is a schematic view of another construction example.
【図１０】他の施工例の概要図である。FIG. 10 is a schematic view of another construction example.
【図１１】泥土の再利用例の概要図である。FIG. 11 is a schematic diagram of an example of reusing mud.
【図１２】３重管の要部断面図である。FIG. 12 is a cross-sectional view of a main part of a triple pipe.
【図１３】圧入を行う場合の例の概要図である。FIG. 13 is a schematic diagram of an example when press-fitting is performed.
【図１４】柱列杭の断面図である。FIG. 14 is a cross-sectional view of a pillar row pile.
【図１５】柱列杭の平明図である。FIG. 15 is a transparent view of a pillar row pile.
【図１６】他の攪拌羽根を有する装置による改良例の工
程概要図であり、その（Ａ）〜（Ｄ）の順で施工が行わ
れる。FIG. 16 is a process outline view of an improved example using an apparatus having another stirring blade, in which construction is performed in the order of (A) to (D).
【図１７】本発明例による改良固結体の外形正面図であ
る。FIG. 17 is a front view of the outer shape of the improved consolidated body according to the example of the present invention.
【図１８】本発明例による改良固結体の外形平面図であ
る。FIG. 18 is a plan view showing the outer shape of an improved consolidated body according to an example of the present invention.
【図１９】比較例による改良固結体の外形正面図であ
る。FIG. 19 is a front view of the outer shape of an improved consolidated body according to a comparative example.
【図２０】比較例による改良固結体の外形平面図であ
る。FIG. 20 is an outline plan view of an improved consolidated body according to a comparative example.
１…ノズル、２…噴射管、２０…噴射管、２４…ノズ
ル、Ｗ…水、Ｇ…改良材、Ｓ…緩んだ地盤部分。1 ... Nozzle, 2 ... Injection pipe, 20 ... Injection pipe, 24 ... Nozzle, W ... Water, G ... Improvement material, S ... Loose ground part.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 扇田 正俊 東京都国立市東三丁目19の７ セジュール 国立Ａ２ (56)参考文献 特開 昭57−3911（ＪＰ，Ａ) 特開 平１−102122（ＪＰ，Ａ) 実表 昭63−503230（ＪＰ，Ｕ) ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Masatoshi Ogita, 7 Sejour, 3-19 Higashi 3-chome, Kunitachi, Tokyo National A2 (56) Reference JP-A-57-3911 (JP, A) JP-A-1-102122 (JP) , A) Actual table 63-503230 (JP, U)
Claims (11)
高圧液噴射ノズルから高圧水を噴射して対象地盤を緩め
て泥土化し、次いでこの緩んだ地盤中に高粘性の自硬性
材料を圧入することにより、前記弛緩泥土を押し上げて
排除するとともに前記自硬性材料による置換を行い改良
体を造成することを特徴とする地盤の改良または強化工
法。1. A target ground is loosened by spraying high-pressure water from a high-pressure liquid spray nozzle provided at the tip of a spray pipe inserted into the ground.
It becomes mud and then self-hardens with high viscosity in this loose ground.
Push the material up to push up the loose mud
A method for improving or strengthening the ground, which comprises eliminating and replacing the self-hardening material to form an improved body.
材料の圧入時点とが異なる請求項１記載の地盤の改良ま
たは強化工法。2. The method for improving or strengthening the ground according to claim 1, wherein the time when the ground is loosened by the high-pressure liquid and the time when the self-hardening material is pressed in are different.
の注出口より基端側に噴射ノズルを設け、噴射注入管の
引上げ過程で地盤の弛緩と自硬性材料の圧入とをほぼ同
時に行う請求項１記載の地盤の改良または強化工法。3. A spout is formed at the tip of the jet injection pipe, and a jet nozzle is provided at the base end side of the spout, so that the loosening of the ground and the press-fitting of the self-hardening material are almost performed during the process of pulling up the jet injection pipe. The method for improving or strengthening the ground according to claim 1, which is performed simultaneously.
が５０kg／cm2 Ｇ以上とする請求項１記載の地盤の改良
または強化工法。4. The method for improving or strengthening the ground according to claim 1, wherein the injection pressure of the high-pressure liquid from the high-pressure liquid injection nozzle is 50 kg / cm 2 G or more.
したものである請求項１記載の地盤の改良または強化工
法。5. The method for improving or strengthening the ground according to claim 1, wherein the liquid for loosening the ground is water added with a surfactant.
良体の造成材料とする請求項１記載の地盤の改良または
強化工法。6. The improved or enhanced method of ground according to claim 1, Construction materials improved body by adding self-hardening material was eliminated mud.
離し、前記上澄液は地盤の弛緩用の液としてそのまま又
は水に添加して再利用する請求項１記載の地盤の改良ま
たは強化工法。7. separating mud which is eliminated and the supernatant and concentrate the mud, the supernatant is the ground of claim 1 wherein the recycled by adding it is or in water as a liquid for loosening the ground Improved or strengthened construction method.
離し、前記濃縮泥土は自硬性材料に添加して改良体の造
成材料として再利用する請求項１記載の地盤の改良また
は強化工法。8. separate the mud which is eliminated and the supernatant and concentrate the mud, the concentrated mud is claim 1 of the ground according improvements or reused as reclamation material for improved body added to the self-hardening material Reinforcement method.
路を地盤の弛緩用液の供給に用い、他方の流路を穿孔時
における削孔水の供給および地盤弛緩後の自硬性材料の
供給に用いる請求項１記載の地盤の改良または強化工
法。9. An injection pipe has two flow passages, one of which is used for supplying a relaxation liquid for the ground, and the other flow passage is used for supplying drilling water during drilling and after relaxation of the ground. The method for improving or strengthening the ground according to claim 1, which is used for supplying a self-hardening material.
流路を地盤の弛緩用液の供給に用い、第２の流路を弛緩
用液による地盤の切削能力向上および泥土の地上へのエ
アリフトを行う圧縮空気の供給に用い、第３の流路を地
盤弛緩後の自硬性材料の供給に用いる請求項１記載の地
盤の改良または強化工法。10. The injection pipe has three flow paths, the first flow path is used for supplying a relaxing liquid for the ground, and the second flow path is used for improving the cutting ability of the ground by the relaxing liquid and mud. The method for improving or strengthening the ground according to claim 1, wherein the method is used for supplying compressed air for airlifting to the ground, and the third flow path is used for supplying the self-hardening material after the ground is relaxed.
に埋設して、杭または壁とする請求項１記載の地盤の改
良または強化工法。11. The method for improving or strengthening the ground according to claim 1, wherein reinforcing bars are inserted into the area to be improved and embedded in the improved body to form piles or walls.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP1991/001688 WO1992021825A1 (en) | 1991-05-31 | 1991-12-03 | Construction method of improving or strengthening ground |
| EP92900892A EP0541812B1 (en) | 1991-05-31 | 1991-12-03 | Construction method of improving or strengthening ground |
| DE69127366T DE69127366T2 (en) | 1991-05-31 | 1991-12-03 | CONSTRUCTION METHOD FOR IMPROVING OR REINFORCING THE GROUND |
| ES92900892T ES2109334T3 (en) | 1991-05-31 | 1991-12-03 | CONSTRUCTION PROCEDURE TO IMPROVE OR STRENGTHEN THE LAND. |
| CA 2087963 CA2087963A1 (en) | 1991-05-31 | 1991-12-03 | Work method of improving or strengthening ground |
| TW80109597A TW199916B (en) | 1991-05-31 | 1991-12-06 |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2-143946 | 1990-06-01 | ||
| JP14394690 | 1990-06-01 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05255925A JPH05255925A (en) | 1993-10-05 |
| JPH07111052B2 true JPH07111052B2 (en) | 1995-11-29 |
Family
ID=15350732
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3129473A Expired - Fee Related JPH07111052B2 (en) | 1990-06-01 | 1991-05-31 | Ground improvement or strengthening method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07111052B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1181295A (en) * | 1997-09-10 | 1999-03-26 | Raito Kogyo Co Ltd | Method for ground improvement |
| JP2007016507A (en) * | 2005-07-08 | 2007-01-25 | Taisei Corp | Ground improvement method and reinforcing method of existing structural foundation |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5550177B2 (en) * | 2010-03-31 | 2014-07-16 | 株式会社不動テトラ | Injection material injection method for ground improvement |
| JP6546720B2 (en) * | 2014-04-15 | 2019-07-17 | 公益財団法人鉄道総合技術研究所 | Liquefaction countermeasure method by ground consolidation using injection method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5827364B2 (en) * | 1980-06-04 | 1983-06-09 | 株式会社 エヌ・アイ・テイ | Ground improvement method and its equipment |
| AT387415B (en) * | 1986-03-03 | 1989-01-25 | Perlmooser Zementwerke Ag | METHOD FOR THE RESTORATION OF DAMAGED PORTABLE, CLOSABLE AND NON-LABELABLE CHANNELS, IN PARTICULAR PROFILE CHANNELS |
| JPH01102122A (en) * | 1987-10-15 | 1989-04-19 | Osaka Bosui Constr Co Ltd | Ground improving work |
-
1991
- 1991-05-31 JP JP3129473A patent/JPH07111052B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1181295A (en) * | 1997-09-10 | 1999-03-26 | Raito Kogyo Co Ltd | Method for ground improvement |
| JP2007016507A (en) * | 2005-07-08 | 2007-01-25 | Taisei Corp | Ground improvement method and reinforcing method of existing structural foundation |
| JP4520913B2 (en) * | 2005-07-08 | 2010-08-11 | 大成建設株式会社 | Ground improvement method and existing structure foundation reinforcement method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05255925A (en) | 1993-10-05 |
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