JP2881353B2 - Ground improvement method - Google Patents
Ground improvement methodInfo
- Publication number
- JP2881353B2 JP2881353B2 JP4033656A JP3365692A JP2881353B2 JP 2881353 B2 JP2881353 B2 JP 2881353B2 JP 4033656 A JP4033656 A JP 4033656A JP 3365692 A JP3365692 A JP 3365692A JP 2881353 B2 JP2881353 B2 JP 2881353B2
- Authority
- JP
- Japan
- Prior art keywords
- amount
- addition
- mixing
- ground
- cement
- 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
Landscapes
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Soil Conditioners And Soil-Stabilizing Materials (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、軟弱地盤、特に好まし
くはピート質土壌地盤の改良方法に関する。The present invention relates to a method for improving soft ground, particularly preferably peaty soil ground.
【０００２】[0002]
【従来の技術】地盤改良方法として、セメント系などの
カルシウム系固化材を用いる混合処理方法が知られてお
り、この方法は、表層処理のほか、深層処理に対しても
採用されている。2. Description of the Related Art As a ground improvement method, a mixing method using a calcium-based solidifying material such as cement is known, and this method is employed not only for surface treatment but also for deep treatment.
【０００３】この場合、深層混合処理の中に、いわゆる
ＣＤＭ工法に代表されるセメントスラリー系機械攪拌工
法がある。また、いわゆるＤＪＭ工法などのセメントや
石灰を粉体のままで噴射攪拌混合する工法も知られてい
る。In this case, there is a cement slurry mechanical stirring method represented by the so-called CDM method in the deep mixing process. There is also known a method such as a so-called DJM method in which cement or lime is jet-stirred and mixed as powder.
【０００４】[0004]
【発明が解決しようとする課題】しかし、この種の混合
処理工法においては、対象土壌によって改良効果が異な
ることは従来知られていたところであるが、本発明者の
知見によれば、特にピート質土壌に対しては、多量の固
化材を添加しても改良効果、特に強度の上昇が充分でな
いことが明らかとなった。However, in this type of mixed treatment method, it has been conventionally known that the improvement effect varies depending on the target soil. It has been clarified that the addition of a large amount of the solidifying agent does not sufficiently improve the soil, especially the increase in strength.
【０００５】したがって、本発明の課題は、この種のピ
ート質土壌等に対して、充分な改良効果を発揮し、もっ
て改良材（固化材）の使用量の増大を防止できる方法を
提供することにある。[0005] Accordingly, an object of the present invention is to provide a method capable of exerting a sufficient improvement effect on this kind of peaty soil and the like, thereby preventing an increase in the amount of the improvement material (solidified material) used. It is in.
【０００６】[0006]
【課題を解決するための手段】上記課題は、地盤材料と
カルシウムイオンを含む改良材とを混合して地盤の固化
を図る方法において、対象改良土に対して、改良材の最
終使用量の一部を添加混合した後、改良材の残量を添加
混合することで解決できる。An object of the present invention is to provide a method for solidifying the ground by mixing a ground material and an improving material containing calcium ions, and to improve the final use amount of the improving material with respect to the target improved soil. This can be solved by adding and mixing the remaining parts of the improving material after adding and mixing the parts.
【０００７】この場合、対象地盤がピート質土壌であ
り、最終使用量の一部を添加混合する事前添加量と、改
良材の残量を添加する本添加量との重量比が、1/14〜2/
1 であると、本発明の効果が顕著となる。In this case, the target ground is peaty soil, and the weight ratio of the pre-addition amount for adding and mixing part of the final usage amount to the main addition amount for adding the remaining amount of the improving material is 1/14. ~ 2 /
When it is 1, the effect of the present invention becomes remarkable.
【０００８】[0008]
【作用】本発明によれば、後述の実施例のように、改良
材（固化材）の使用量を過度にすることなく、所望の強
度を得ることができ、改良コストの増大を抑制できる。According to the present invention, a desired strength can be obtained without excessive use of the improving material (solidifying material) as in the examples described later, and an increase in improvement cost can be suppressed.
【０００９】本発明では、地盤材料とカルシウムイオン
を含む改良材とを混合して地盤の固化を図る方法におい
て、対象改良土に対して改良材の最終使用量の一部を添
加混合する事前添加の後、改良材の残量を添加混合する
本添加を行う。According to the present invention, there is provided a method for solidifying the ground by mixing a ground material and an improving material containing calcium ions, wherein a part of the final usage of the improving material is added to and mixed with the target improved soil. After that, the main addition of adding and mixing the remaining amount of the improving material is performed.
【００１０】この種の地盤改良に際して、本発明のよう
に、事前添加と本添加とを分けて行うことは従来全くな
されていない。In this kind of ground improvement, it has not been done at all in the prior art to separately perform preliminary addition and main addition as in the present invention.
【００１１】しかるに、本発明に従って、事前添加法を
採用すると、強度の向上が成される。この理由は定かで
ないが、次記の化学的および物理的理由が考えられる。
（化学的理由）ピート質土壌に含まれるフミン酸は、セ
メントの硬化阻害物質として知られている。本発明に従
って、事前添加することにより、そのフミン酸がカルシ
ウムイオンと反応して不溶性のフミン酸カルシウムとし
て固定されるために、本添加した場合には、そのフミン
酸による阻害作用が既に喪失し、もってその後改良材の
反応が円滑に行われる。 （物理的理由）第１に、事前添加により、見掛けの含水
比が低下し、この状態で本添加の改良材との反応が行わ
れるので、反応が速やかに進行すること、第２に事前添
加分の改良材のカルシウムイオンによる土粒子の団粒化
がまず行われ、コンシステンシーが変化した状態の後
に、本添加による固化反応が進むので、その反応が良好
となること。しかるに、本発明者らは、種々の実験によ
り、化学的理由はなく、もっぱら物理的理由により、後
述の効果が奏せられると考えている。However, when the pre-addition method is employed according to the present invention, the strength is improved. The reason for this is not clear, but the following chemical and physical reasons are possible.
(Chemical reason) Humic acid contained in peaty soil is known as a hardening inhibitor of cement. According to the present invention, by pre-addition, the humic acid reacts with calcium ions and is fixed as insoluble calcium humate. Thereafter, the reaction of the improving material is smoothly performed. (Physical reasons) First, the pre-addition reduces the apparent water content, and in this state, the reaction with the improving agent of the main addition is performed, so that the reaction proceeds rapidly. Agglomeration of the soil particles by calcium ions of the modifier is first performed, and after the consistency is changed, the solidification reaction by this addition proceeds, so that the reaction is good. However, the present inventors believe that the effects described below can be obtained solely for physical reasons without any chemical reason through various experiments.
【００１２】一方、対象地盤としては、ピート質土壌で
あり、フミン酸含有量としては10重量％（以下断りのな
い限り％は重量％を示す）以上、特に15％以上の場合に
有効に適用される。また、最終使用量の一部を添加混合
する事前添加量と、改良材の残量を添加する本添加量と
の重量比が、1/14〜2/1 であるのが後述の実施例からも
好適である。On the other hand, the target ground is peaty soil, and the humic acid content is more than 10% by weight (% means% by weight unless otherwise noted), and is particularly effective when it is 15% or more. Is done. The weight ratio between the pre-addition amount for adding and mixing part of the final usage amount and the main addition amount for adding the remaining amount of the improving material is 1/14 to 2/1 from the examples described later. Are also suitable.
【００１３】本発明に用いるカルシウムイオンを含む改
良材としては、生石灰、消石灰、セメントまたはセメン
ト系固化材を挙げることができる。これらは、２種以上
を併用することができる。セメントとしては、ポルトラ
ンドセメントのほか、高炉セメントなども挙げることが
できる。セメント系固化材としては、エトリンガイト
系、特に混合タイプのほか、焼成微粉砕タイプのものを
例示できる。後者の例としては、秩父セメント社製「チ
チブソイルフィックス」が代表的である。これはアルミ
ネート系特殊クリンカーをベースとし、微粉砕したもの
である。Examples of the calcium ion-containing improving material used in the present invention include quick lime, slaked lime, cement and cement-based solidified materials. These can be used in combination of two or more. Examples of the cement include Portland cement, blast furnace cement, and the like. Examples of the cement-based solidifying material include an ettringite-based material, particularly a mixed type, and a fired and finely pulverized type. A typical example of the latter is "Chichibu Soil Fix" manufactured by Chichibu Cement Co., Ltd. This is based on an aluminate-based special clinker and is finely pulverized.
【００１４】改良材の事前添加および本添加態様として
は、これを用いる改良工法の実際により適宜選択でき
る。混合の方法は、深層混合工法の場合、攪拌羽根、ス
クリューオーガー、圧縮空気または高圧流体のもってい
るエネルギーなどを利用できる。また、この深層混合工
法の場合、例えば攪拌混合軸の貫入時に事前添加を、引
抜き時において本添加を行うことができる。表層混合処
理の場合には、スタビライザーやバックホーなどを利用
できる。改良材は粉体のままのほか、水などとの混合ス
ラリーとして添加できる。The pre-addition and the addition of the improver can be appropriately selected depending on the actual method of the improvement using the improver. As a mixing method, in the case of the deep mixing method, a stirring blade, a screw auger, compressed air or energy of a high-pressure fluid can be used. In the case of this deep mixing method, for example, pre-addition can be performed at the time of penetration of the stirring and mixing shaft, and main addition can be performed at the time of drawing. In the case of the surface mixing treatment, a stabilizer, a backhoe, or the like can be used. The improving material can be added as a powder slurry or as a mixed slurry with water or the like.
【００１５】[0015]
【実施例】以下本発明の効果を実施例により明らかにす
る。表１に示す５種類の土壌を試料土とし、次記の固化
材を用い、本発明に従い事前添加の効果を一軸圧縮強度
として調べた。 セメント系固化材：「チチブソイルフィックス11」（秩
父セメント社製） 生石灰：青倉石灰工業社製 消石灰：青倉石灰工業社製 一軸圧縮強度試験には、５×10cmφの供試体を作製しこ
れを湿空養生したものを供試体としたものである。各試
料土に対する用いた固化材の種類、事前添加および本添
加量は表２に示す通りである。同表中、「ＳＸ11」とは
前述の「チチブソイルフィックス11」を指称する。EXAMPLES The effects of the present invention will be clarified by the following examples. Five types of soils shown in Table 1 were used as sample soils, and using the following solidifying material, the effect of prior addition was examined as uniaxial compressive strength according to the present invention. Cement-based solidifying material: "Titibusoil Fix 11" (manufactured by Chichibu Cement Co.) Quicklime: manufactured by Aokura Lime Industry Co., Ltd. Slaked lime: manufactured by Aokura Lime Industry Co., Ltd. For the uniaxial compression strength test, a 5 × 10 cmφ specimen was prepared and wetted. The specimens were air-cured. Table 2 shows the type, pre-addition and main addition amount of the solidifying material used for each sample soil. In the table, “SX11” refers to the above-mentioned “Titty Soil Fix 11”.
【００１６】結果を図１〜図３に示した。図１は練り置
き時間と一軸圧縮強度（28日強度）との相関を、図２に
事前添加、本添加量と一軸圧縮強度との相関を、図３に
各種土壌の相違による改良効果の相違を示している。さ
らに、図４は本添加材料を生石灰に代えて、ローム土壌
に対して本発明を適用した場合の練り置き時間と一軸圧
縮強度（３日強度）との相関を示したものである。The results are shown in FIGS. Fig. 1 shows the correlation between the kneading time and the uniaxial compressive strength (28 days strength), Fig. 2 shows the correlation between the pre-addition and the amount added, and the uniaxial compressive strength. Is shown. FIG. 4 shows the correlation between the mixing time and the uniaxial compressive strength (three-day strength) when the present invention is applied to loam soil in place of the quicklime as the additive material.
【００１７】[0017]
【表１】 [Table 1]
【００１８】[0018]
【表２】 [Table 2]
【００１９】（考察）図１において、「練り置き時間」
は事前添加混合後、本添加までの時間を示す。また、ミ
ルクの状態とドライの状態を区別して実験したのは、前
者をいわゆるＣＤＭ工法に、後者をＤＪＭ工法に適用す
ることを想定したものである。これらの工法の内容は、
「基礎工」1989年８月号にそれぞれ記載されている。(Consideration) In FIG. 1, "kneading time"
Indicates the time from the pre-addition mixing to the main addition. In addition, the experiment in which the milk state and the dry state are distinguished is based on the assumption that the former is applied to a so-called CDM method and the latter is applied to a DJM method. The contents of these methods are
"Basic construction" is described in the August 1989 issue.
【００２０】結果を見ると、事前添加および本添加にセ
メント系固化材を用いた場合、練り置き直後から大きな
強度の向上が見られる。また、生石灰または消石灰を事
前添加材料とし、本添加材料をセメント系固化材とした
場合、セメント系固化材の使用量が半減しているにも係
わらず、強度の低下が少ないことが判明した。According to the results, when the cement-based solidifying material is used for the pre-addition and the main addition, a great improvement in the strength is seen immediately after the kneading. In addition, when quick lime or slaked lime was used as a pre-added material and the present added material was used as a cement-based solidified material, it was found that the strength was hardly reduced even though the usage of the cement-based solidified material was halved.
【００２１】図２は、事前添加量と本添加量の合計量が
300 kg/m3 となる条件の下で、各添加量比を変更したも
ので、事前添加および本添加にセメント系固化材を用い
た場合、添加量比が１：１まで改善効果が見られ、生石
灰または消石灰を事前添加材料とし、本添加材料をセメ
ント系固化材とした場合、１：２まで改善効果が見られ
た。FIG. 2 shows that the total amount of the pre-addition amount and the main addition amount is
Under conditions to be 300 kg / m 3, obtained by changing each amount ratio, when using a cement solidifying material in advance added and the additive, the addition amount ratio is 1: improvement is seen 1 In the case where quick lime or slaked lime was used as a pre-added material and the added material was a cement-based solidified material, an improvement effect of up to 1: 2 was observed.
【００２２】図３は、各種試料土に対して、事前添加
量：本添加量＝１：１として、練り置き時間の変化によ
る強度変化を調べたもので、いずれもある練り置き時間
で元を上回る強度を示すことが判明した。また、図３に
示す結果において、図１に示した指扇ピートの結果と比
較参照してみると、竜ヶ崎ピートの強度向上が少ないの
は、表１に示すように、フミン酸の含有量が少ないため
であると考えられる。したがって、本発明は、フミン酸
の量が多い場合に特に好適であることが逆に明らかとな
った。FIG. 3 shows the change in strength due to the change in the mixing time with various amounts of sample soil, with the pre-adding amount: the main adding amount = 1: 1. It has been found to exhibit higher strength. In comparison with the results of the finger fan peat shown in FIG. 1 in the results shown in FIG. 3, the strength improvement of Ryugasaki peat is small, as shown in Table 1, because the humic acid content is small. It is thought that it is. Accordingly, it has been clarified that the present invention is particularly suitable when the amount of humic acid is large.
【００２３】図４により、本添加材料として、生石灰で
も同様の効果を示すことから、本発明において、本添加
材料の種類に限定されないことが判明するであろう。FIG. 4 shows that the same effect is obtained with quicklime as the present additive material, and it will be understood that the present invention is not limited to the type of the present additive material.
【００２４】さらに、各結果から、練り置き時間として
は、練り置き直後以降、好ましくは１時間以降が好適で
ある。Further, from each result, the kneading time is preferably immediately after kneading, preferably 1 hour or more.
【００２５】[0025]
【発明の効果】以上の通り、本発明によれば、ピート質
土壌などに対して、充分な改良効果を発揮し、もって改
良材（固化材）の使用量の増大を防止できるなどの利点
がもたらされる。As described above, according to the present invention, there is an advantage that a sufficient improvement effect can be exerted on peaty soil and the like, thereby preventing an increase in the amount of the improvement material (solidifying material) used. Brought.
【図１】本発明の実施例を示すグラフである。FIG. 1 is a graph showing an example of the present invention.
【図２】他の実施例を示すグラフである。FIG. 2 is a graph showing another embodiment.
【図３】さらに別の実施例を示すグラフである。FIG. 3 is a graph showing still another embodiment.
【図４】さらに別の実施例を示すグラフである。FIG. 4 is a graph showing still another embodiment.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 酒巻 克之 埼玉県熊谷市月見町二丁目１番１号 秩 父セメント株式会社中央研究所内 (72)発明者 佐藤 暢政 埼玉県熊谷市月見町二丁目１番１号 秩 父セメント株式会社中央研究所内 (58)調査した分野(Int.Cl.6，ＤＢ名) E02D 3/00 101 C09K 17/06 E02D 3/12 102 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuyuki Sakamaki 2-1-1, Tsukimi-cho, Kumagaya-shi, Saitama Chichibu Cement Co., Ltd. Central Research Laboratory (72) Inventor Nobumasa Sato Tsukimi-cho, Kumagaya-shi, Saitama 2-1-1, Chichibu Cement Co., Ltd. Central Research Laboratory (58) Field surveyed (Int. Cl. 6 , DB name) E02D 3/00 101 C09K 17/06 E02D 3/12 102
Claims (2)
とを混合して地盤の固化を図る方法において、 対象改良土に対して、改良材の最終使用量の一部を添加
混合した後、改良材の残量を添加混合することを特徴と
する地盤改良方法。In a method of solidifying a ground by mixing a ground material and an improving material containing calcium ions, a part of a final use amount of the improving material is added to a target improved soil and mixed. A ground improvement method characterized by adding and mixing the remaining amount of material.
量の一部を添加混合する事前添加量と、改良材の残量を
添加する本添加量との重量比が、1/14〜2/1 である請求
項１記載の地盤改良方法。2. The target ground is peaty soil, and the weight ratio of the pre-addition amount for adding and mixing a part of the final usage amount to the main addition amount for adding the remaining amount of the improving material is 1/14 ~. The ground improvement method according to claim 1, wherein the ratio is 2/1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4033656A JP2881353B2 (en) | 1992-02-20 | 1992-02-20 | Ground improvement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4033656A JP2881353B2 (en) | 1992-02-20 | 1992-02-20 | Ground improvement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05230821A JPH05230821A (en) | 1993-09-07 |
| JP2881353B2 true JP2881353B2 (en) | 1999-04-12 |
Family
ID=12392494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4033656A Expired - Fee Related JP2881353B2 (en) | 1992-02-20 | 1992-02-20 | Ground improvement method |
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| Country | Link |
|---|---|
| JP (1) | JP2881353B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4574386B2 (en) * | 2005-02-18 | 2010-11-04 | 日本国土開発株式会社 | Mixing method of solidifying material in improved soil and mixing method of solidifying material and auxiliary in improved soil |
| JP4889051B2 (en) * | 2008-11-25 | 2012-02-29 | ライト工業株式会社 | How to build a continuous wall |
| JP4889052B2 (en) * | 2008-11-25 | 2012-02-29 | ライト工業株式会社 | How to build a continuous wall |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5653165B2 (en) * | 1977-07-07 | 1981-12-17 | ||
| JPH02213664A (en) * | 1989-02-13 | 1990-08-24 | Matsushita Refrig Co Ltd | Condensing device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5839347Y2 (en) * | 1979-08-22 | 1983-09-05 | 星崎電機株式会社 | Filter cleaning device for forced air-cooled condenser in refrigeration cycle equipment |
| JPH01116313U (en) * | 1988-01-28 | 1989-08-04 |
-
1992
- 1992-02-20 JP JP4033656A patent/JP2881353B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5653165B2 (en) * | 1977-07-07 | 1981-12-17 | ||
| JPH02213664A (en) * | 1989-02-13 | 1990-08-24 | Matsushita Refrig Co Ltd | Condensing device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05230821A (en) | 1993-09-07 |
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