JPH11131465A - Improvement method for poor subsoil - Google Patents
Improvement method for poor subsoilInfo
- Publication number
- JPH11131465A JPH11131465A JP23583098A JP23583098A JPH11131465A JP H11131465 A JPH11131465 A JP H11131465A JP 23583098 A JP23583098 A JP 23583098A JP 23583098 A JP23583098 A JP 23583098A JP H11131465 A JPH11131465 A JP H11131465A
- Authority
- JP
- Japan
- Prior art keywords
- ground
- water
- sand
- drainage
- vacuum pump
- 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
- 238000000034 method Methods 0.000 title claims abstract description 76
- 239000000463 material Substances 0.000 claims abstract description 181
- 239000004576 sand Substances 0.000 claims abstract description 101
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 81
- 238000007596 consolidation process Methods 0.000 claims description 51
- 239000002689 soil Substances 0.000 claims description 38
- 239000013049 sediment Substances 0.000 claims description 23
- 239000012778 molding material Substances 0.000 claims description 18
- 238000010276 construction Methods 0.000 claims description 17
- 229920005615 natural polymer Polymers 0.000 claims description 9
- 238000007599 discharging Methods 0.000 claims description 4
- 238000005266 casting Methods 0.000 claims description 2
- 239000000835 fiber Substances 0.000 description 15
- 229920003023 plastic Polymers 0.000 description 11
- 239000004033 plastic Substances 0.000 description 11
- 239000002245 particle Substances 0.000 description 7
- 239000011148 porous material Substances 0.000 description 7
- 239000011111 cardboard Substances 0.000 description 5
- 239000000123 paper Substances 0.000 description 5
- 241000196324 Embryophyta Species 0.000 description 4
- 229920002472 Starch Polymers 0.000 description 4
- 230000018044 dehydration Effects 0.000 description 4
- 238000006297 dehydration reaction Methods 0.000 description 4
- 244000005700 microbiome Species 0.000 description 4
- 235000019698 starch Nutrition 0.000 description 4
- 229920003002 synthetic resin Polymers 0.000 description 4
- 239000000057 synthetic resin Substances 0.000 description 4
- 239000000843 powder Substances 0.000 description 3
- 238000007711 solidification Methods 0.000 description 3
- 230000008023 solidification Effects 0.000 description 3
- 244000215068 Acacia senegal Species 0.000 description 2
- 208000003643 Callosities Diseases 0.000 description 2
- 108010010803 Gelatin Proteins 0.000 description 2
- 108010068370 Glutens Proteins 0.000 description 2
- 229920000084 Gum arabic Polymers 0.000 description 2
- 244000043261 Hevea brasiliensis Species 0.000 description 2
- 206010020649 Hyperkeratosis Diseases 0.000 description 2
- 240000007594 Oryza sativa Species 0.000 description 2
- 235000007164 Oryza sativa Nutrition 0.000 description 2
- 244000061456 Solanum tuberosum Species 0.000 description 2
- 235000002595 Solanum tuberosum Nutrition 0.000 description 2
- 241000209140 Triticum Species 0.000 description 2
- 235000021307 Triticum Nutrition 0.000 description 2
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 2
- 240000008042 Zea mays Species 0.000 description 2
- 235000005824 Zea mays ssp. parviglumis Nutrition 0.000 description 2
- 235000002017 Zea mays subsp mays Nutrition 0.000 description 2
- 239000000205 acacia gum Substances 0.000 description 2
- 235000010489 acacia gum Nutrition 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 235000021120 animal protein Nutrition 0.000 description 2
- 239000005018 casein Substances 0.000 description 2
- BECPQYXYKAMYBN-UHFFFAOYSA-N casein, tech. Chemical compound NCCCCC(C(O)=O)N=C(O)C(CC(O)=O)N=C(O)C(CCC(O)=N)N=C(O)C(CC(C)C)N=C(O)C(CCC(O)=O)N=C(O)C(CC(O)=O)N=C(O)C(CCC(O)=O)N=C(O)C(C(C)O)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=O)N=C(O)C(CCC(O)=O)N=C(O)C(COP(O)(O)=O)N=C(O)C(CCC(O)=N)N=C(O)C(N)CC1=CC=CC=C1 BECPQYXYKAMYBN-UHFFFAOYSA-N 0.000 description 2
- 235000021240 caseins Nutrition 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 235000005822 corn Nutrition 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000008273 gelatin Substances 0.000 description 2
- 229920000159 gelatin Polymers 0.000 description 2
- 235000019322 gelatine Nutrition 0.000 description 2
- 235000011852 gelatine desserts Nutrition 0.000 description 2
- 235000021312 gluten Nutrition 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 229920003052 natural elastomer Polymers 0.000 description 2
- 229920001194 natural rubber Polymers 0.000 description 2
- 239000004745 nonwoven fabric Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 235000012015 potatoes Nutrition 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 235000009566 rice Nutrition 0.000 description 2
- 239000008107 starch Substances 0.000 description 2
- 235000013311 vegetables Nutrition 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- GNFTZDOKVXKIBK-UHFFFAOYSA-N 3-(2-methoxyethoxy)benzohydrazide Chemical compound COCCOC1=CC=CC(C(=O)NN)=C1 GNFTZDOKVXKIBK-UHFFFAOYSA-N 0.000 description 1
- FGUUSXIOTUKUDN-IBGZPJMESA-N C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 Chemical compound C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 FGUUSXIOTUKUDN-IBGZPJMESA-N 0.000 description 1
- 238000006065 biodegradation reaction Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 235000013339 cereals Nutrition 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000010169 landfilling Methods 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/02—Improving by compacting
- E02D3/10—Improving by compacting by watering, draining, de-aerating or blasting, e.g. by installing sand or wick drains
Landscapes
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Agronomy & Crop Science (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Biological Depolymerization Polymers (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えば湖沼周囲の
埋立造成区域などの軟弱地盤に多量に含まれる水と空気
とを排出することで、硬質地盤へと改良する軟弱地盤の
改良工法に関する。詳細には軟弱地盤に含まれる水と空
気とを効率よく、しかも確実に排出することができる軟
弱地盤の改良工法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving a soft ground by discharging a large amount of water and air contained in a soft ground such as a land reclamation area around a lake or the like, thereby improving the soft ground. More particularly, the present invention relates to a method for improving soft ground, which can efficiently and surely discharge water and air contained in soft ground.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】従来、
軟弱軟弱地盤の改良工法としては、サンドドレーン工法
やペーパードレーン工法が代表的なものとして挙げられ
るバーチカルドレーン工法がある。サンドドレーン工法
は、軟弱地盤中に適当な間隔で鉛直方向に数多くのサン
ドパイル（人工的に設けた砂柱）を設置し、このサンド
パイルを通して地盤中の水を抜き取って地盤の圧密と強
度増加を促進し、硬質地盤へと改良する方法である。2. Description of the Related Art
As a method of improving soft and soft ground, there is a vertical drain construction method which is typically exemplified by a sand drain construction method and a paper drain construction method. In the sand drain method, a number of sand piles (artificial sand columns) are installed vertically at appropriate intervals in soft ground, and water in the ground is extracted through these sand piles to increase the consolidation and strength of the ground. This is a method of promoting the formation of a hard ground.
【０００３】一方、ペーパードレン工法は、軟弱な地盤
の圧密を促進するためのものであり、厚さ３ｍｍ、幅１
００ｍｍ程度の帯状原紙の中に縦方向に連続した通水孔
を設けたカードボードをマンドレルによって適当な間隔
に打ち込み設置し、このカードボードを通して地盤中の
水を抜き取るようにしたものである。On the other hand, the paper drain method is for promoting the compaction of soft ground, and has a thickness of 3 mm and a width of 1 mm.
A cardboard provided with water holes continuous in the vertical direction in a band-shaped base paper of about 00 mm is driven at a suitable interval by a mandrel, and the water in the ground is drained through the cardboard.
【０００４】ところが、これらサンドドレーン工法やペ
ーパードレーン工法などのバーチカルドレーン工法にあ
っては、処理を開始した当初はよいが、水の抜き取りが
進行するにつれて、地盤中に水の通路となるべき間隙が
なくなり、遂には排水されないという不具合が生じてい
た。[0004] However, in the vertical drain method such as the sand drain method and the paper drain method, it is good at the beginning of the treatment, but as the drainage proceeds, a gap that becomes a water passage in the ground is formed. Had disappeared, and finally there was a problem that it was not drained.
【０００５】そこで、排水効率をさらに高める目的で提
案されたのが図１６に示す改良工法である。この方法
は、プラスチックドレーンを打設した後、カードボード
１の上端部１ａにこれと接触するように水平状に真空ポ
ンプ３に連結した有孔管２を配置し、これらカードボー
ド１及び有孔管２を砂層４で覆うようにしたものであ
り、真空ポンプ３に連結した有孔管２を通して地盤Ａ上
面を負圧とすることで、地盤Ａ中における間隙水圧との
差を大きくし、地盤Ａ中の水をカードボード１及び有孔
管２を介して排水するようにしたものである。To improve drainage efficiency, an improved method shown in FIG. 16 has been proposed. In this method, after a plastic drain is cast, a perforated pipe 2 connected to a vacuum pump 3 is horizontally disposed at the upper end 1a of the card board 1 so as to come into contact with the plastic drain, and the card board 1 and the perforated pipe are arranged. The pipe 2 is covered with a sand layer 4, and the upper surface of the ground A is made to have a negative pressure through the perforated pipe 2 connected to the vacuum pump 3, thereby increasing the difference from the pore water pressure in the ground A. The water in A is drained through the card board 1 and the perforated pipe 2.
【０００６】しかしながら、真空ポンプ３に連結した有
孔管２は砂層４で覆われているだけであり、地盤Ａ上面
に十分な負圧環境を創り出すことができない。また有孔
管２の孔５が砂や地盤Ａ内からの土砂などで目詰まりを
生じることもあり、地盤Ａの深部まで圧力差による水の
吸い出し効果が得られないなどの不具合があり、十分な
排水ができないことがあった。However, the perforated pipe 2 connected to the vacuum pump 3 is merely covered with the sand layer 4, and a sufficient negative pressure environment cannot be created on the upper surface of the ground A. In addition, the hole 5 of the perforated pipe 2 may be clogged with sand or earth and sand from inside the ground A, and there is a problem that a water suction effect cannot be obtained due to a pressure difference to a deep portion of the ground A. Drainage was not always possible.
【０００７】また、図面に示した改良工法の場合には、
地盤Ａ上面に負圧環境を創り出すために強力な吸引力で
吸引しなければならず、しかも地盤Ａ中の排水が完了す
るまでの間中吸引しつづけることから、真空ポンプ３を
作動させるために消費される電力、軽油も多く、地盤上
面に負圧環境を創り出すために要する費用は莫大なもの
となっていた。In the case of the improved construction method shown in the drawings,
In order to create a negative pressure environment on the upper surface of the ground A, it is necessary to suction with a strong suction force, and since the suction in the ground A is continued until the drainage is completed, the vacuum pump 3 is operated. The amount of power and light oil consumed is large, and the cost required to create a negative pressure environment on the ground surface has been enormous.
【０００８】本発明は、このような事情に鑑みなされた
ものであり、地盤中に含まれる水と空気とを効率よく、
しかも確実に排出することができる軟弱地盤の改良工法
を提供することを目的とするものである。[0008] The present invention has been made in view of such circumstances, and efficiently removes water and air contained in the ground.
Moreover, it is an object of the present invention to provide an improved method for soft ground that can be reliably discharged.
【０００９】また、例えば湖沼周囲の埋立造成区域など
の軟弱地盤にあっては、地盤中に多量の水と空気とが含
まれており、このような地盤改良には、上述の費用や労
力だけではなく、３ヶ月から半年、場合によっては１年
といった長期に渡る施工期間を必要としていた。[0009] In the case of soft ground such as a landfill area around a lake, a large amount of water and air is contained in the ground, and such ground improvement requires only the cost and labor described above. Instead, it required a long construction period of three months to six months, and in some cases one year.
【００１０】また、埋立造成時には、埋立造成区域の周
囲を浚渫することから、その際に生じる浚渫泥の処理に
は、別に設けた浚渫泥用の処理プールに運び入れて処理
しなければならず、その手間だけでも大変な労力と時間
と費用とを必要としていた。[0010] In addition, since the area around the landfill area is dredged during landfilling, the dredging mud generated at that time must be carried to a separate treatment pool for dredging mud. However, even that time alone required a great deal of labor, time and money.
【００１１】本発明の他の目的は、例えば湖沼州の埋立
造成区域などの軟弱地盤を硬質地盤へと改良するととも
に、その際に生じる浚渫泥、（あるいは別の工事や浚渫
作業などに伴って生じた浚渫泥であってもよい）も確実
に処理することができる軟弱地盤の改良工法を提供する
ことである。Another object of the present invention is to improve a soft ground such as a land reclamation area in a lake state into a hard ground, and to generate dredging mud (or other work or dredging work) at that time. It is an object of the present invention to provide an improved method for soft ground that can reliably treat the generated dredging mud.
【００１２】[0012]
【課題を解決するための手段】上記目的を達成するた
め、請求項１記載の発明は、以下のａ）〜ｈ）の工程を
有することを特徴とする軟弱地盤の改良工法をその要旨
とした。 ａ） 鉛直ト゛レーン材を上端部を残して地盤中に所定の
間隔をおいて打設することにより、地盤中に鉛直排水壁
を造成する工程、 ｂ） 前記鉛直ト゛レーン材上端部と接触するように水平
状に真空ポンプに連結した通水材を配置する工程、 ｃ） 前記鉛直ト゛レーン材上端部及び通水材を砂層で覆
う工程、 ｄ） 前記地盤上を前記鉛直ト゛レーン材上端部、通水材
及び砂層とともに気密シートで覆う工程、 ｅ） 前記真空ポンプを作動させて地盤上面に負圧の状
態を造り出す工程、 ｆ） 前記地盤の圧密沈下後の凹部内に土砂を撒き出す
工程、 ｇ） 前記土砂層に前記気密シートを貫通して前記砂層
に至る深さまで鉛直ト゛レーン材を打設する工程、 ｈ） 前記真空ポンプを作動させて前記地盤上面に負圧
の状態を造り出し、前記土砂層中に打設した鉛直ト゛レー
ン材を介して土砂層中の水及び空気を排出させる工程。In order to achieve the above-mentioned object, the gist of the present invention is to provide a method for improving soft ground characterized by having the following steps a) to h). . a) forming a vertical drainage wall in the ground by placing a vertical train material in the ground at a predetermined interval while leaving the upper end thereof; b) contacting the vertical train material with the upper end of the vertical train material. Arranging the water-permeable material connected to the vacuum pump horizontally; c) covering the upper end of the vertical train material and the water-permeable material with a sand layer; d) upper end of the vertical train material on the ground, the water-permeable material. E) a step of operating the vacuum pump to create a negative pressure state on the ground surface, f) a step of dispersing earth and sand in a concave portion of the ground after consolidation settlement, and g) the above. A step of driving a vertical train material through the airtight sheet to a depth reaching the sand layer in the soil layer, h) operating the vacuum pump to create a negative pressure state on the ground surface, and Casting Step of discharging the water and air of sediment layer was via a vertical Doreen material.
【００１３】請求項２記載の発明は、ｅ）、ｆ）、ｇ）
の工程を繰り返すことを特徴とする軟弱地盤の改良工法
をその要旨とした。The invention according to claim 2 provides e), f) and g).
The main idea is to improve the soft ground by repeating the above steps.
【００１４】請求項３記載の発明は、気密シート上に撒
き出す土砂が浚渫泥であることを特徴とする軟弱地盤の
改良工法をその要旨とする。The gist of the invention according to claim 3 is an improved method for soft ground characterized in that the earth and sand scattered on the airtight sheet is dredge mud.
【００１５】請求項４記載の発明は、各工程に使用され
る鉛直ト゛レーン材、通水材及び気密シートのいずれか又
は全てが、生分解性成形材料よりなることを特徴とする
軟弱地盤の改良工法をその要旨とした。According to a fourth aspect of the present invention, there is provided an improved soft ground characterized in that any or all of the vertical train material, the water-permeable material and the airtight sheet used in each step are made of a biodegradable molding material. The construction method was the gist.
【００１６】請求項５記載の発明は、生分解性成形材料
が天然高分子を主体とすることを特徴とする軟弱地盤の
改良工法をその要旨とした。The gist of the invention according to claim 5 is a method of improving soft ground, characterized in that the biodegradable molding material is mainly composed of a natural polymer.
【００１７】請求項６記載の発明は、真空ポンプを間欠
的に作動させることで、地盤上面に常圧及び負圧の状態
を交互に造り出す工程をさらに含むことを特徴とする軟
弱地盤の改良工法をその要旨とした。According to a sixth aspect of the present invention, there is provided a method of improving soft ground, further comprising the step of intermittently operating a vacuum pump to alternately create a normal pressure state and a negative pressure state on the ground surface. Was the gist.
【００１８】請求項７記載の発明は、地盤上面が負圧の
状態から常圧の状態へと移行するときに、地盤上面に空
気を送り込むことを特徴とする軟弱地盤の改良工法をそ
の要旨とした。According to a seventh aspect of the present invention, there is provided an improved method of soft ground characterized by blowing air into the upper surface of the ground when the upper surface of the ground shifts from a negative pressure state to a normal pressure state. did.
【００１９】請求項８記載の発明は、鉛直ト゛レーン材を
振動させるようにしたことを特徴とする軟弱地盤の改良
工法をその要旨とした。The gist of the invention described in claim 8 is a method of improving soft ground characterized by vibrating a vertical train material.
【００２０】請求項９記載の発明は、以下のａ）〜ｆ）
の工程を有することを特徴とする軟弱地盤の改良工法を
その要旨とした。 ａ） 圧密沈下後の地盤の凹部底面に、真空ポンプと連
結し、排水ポンプを備える真空タンクと、同真空タンク
と接続した第１の排水材とを設置すると共に、この第１
の排水材と接するように、所定の間隔をおいて第１の水
平ト゛レーン材を敷設する工程、 ｂ） 前記地盤の凹部内に土砂を撒き出す工程、 ｃ） 前記真空ポンプを作動させて、真空タンク、第１
の排水材、第１の水平ト゛レーン材を介して土砂層に含ま
れる水分及び空気を除去し、土砂層を固化させる工程、 ｄ） 前記固化した土砂上面に、第２の排水材を設置
し、この第２の排水材に接するように、所定の間隔をお
いて第２の水平ト゛レーン材を敷設すると共に、前記第２
の排水材と前記第１の排水材とを可撓管を介して接続す
る工程、 ｅ） 前記凹部内に再度土砂を撒き出す工程、 ｆ） 前記真空ポンプを作動させて、真空タンク、第
１、第２の排水材、第１、第２の水平ト゛レーン材、可撓
管を介して土砂層に含まれる水分及び空気を除去し、土
砂層を固化させる工程。[0020] The invention according to claim 9 provides the following a) to f).
The purpose of the present invention is to provide a method for improving soft ground characterized by having the following steps. a) A vacuum tank connected to a vacuum pump and provided with a drainage pump and a first drainage material connected to the vacuum tank are installed on the bottom of the concave portion of the ground after consolidation settlement, and the first drainage material is connected to the vacuum tank.
Laying a first horizontal train material at a predetermined interval so as to be in contact with the drainage material of (b), b) spouting earth and sand into the concave portion of the ground, c) operating the vacuum pump to vacuum Tank, first
Removing the water and air contained in the sediment layer through the first drainage material and the first horizontal train material to solidify the sediment layer; d) installing a second drainage material on the solidified soil and sand upper surface; A second horizontal train member is laid at a predetermined interval so as to be in contact with the second drainage member, and
Connecting the drainage material and the first drainage material through a flexible pipe, e) re-spreading the earth and sand into the concave portion, f) operating the vacuum pump to form a vacuum tank, Removing the moisture and air contained in the sediment layer through the second drainage material, the first and second horizontal train materials, and the flexible pipe, and solidifying the sediment layer.
【００２１】請求項１０記載の発明は、ａ）の工程にお
ける地盤を圧密沈下させて地盤に凹部を造成する工法
が、以下のア）〜オ）の工程からなることを特徴とする
軟弱地盤の改良工法をその要旨とした。 ア） 鉛直ト゛レーン材を上端部を残して地盤中に所定の
間隔をおいて打設することにより、地盤中に鉛直排水壁
を造成する工程、 イ） 前記鉛直ト゛レーン材上端部と接触するように水平
状に真空ポンプに連結した通水材を配置する工程、 ウ） 前記鉛直ト゛レーン材上端部及び通水材を砂層で覆
う工程、 エ） 前記地盤上を前記鉛直ト゛レーン材上端部、通水材
及び砂層とともに気密シートで覆う工程、 オ） 前記真空ポンプを作動させて地盤上面に負圧の状
態を造り出す工程。According to a tenth aspect of the present invention, in the soft ground, the method of forming a concave portion in the ground by consolidating the ground in the step a) comprises the following steps a) to e). The improved method was the gist. A) a step of forming a vertical drainage wall in the ground by placing a vertical train material in the ground at a predetermined interval while leaving the upper end thereof, a) making contact with the upper end of the vertical train material. Arranging the water-permeable material connected to the vacuum pump horizontally; c) covering the upper end of the vertical train material and the water-permeable material with a sand layer; d) upper end of the vertical train material on the ground, the water-permeable material. And a step of covering with an airtight sheet together with the sand layer. E) a step of operating the vacuum pump to create a negative pressure state on the ground surface.
【００２２】請求項１１記載の発明は、ｄ）、ｅ）、
ｆ）の工程を繰り返すことを特徴とする軟弱地盤の改良
工法をその要旨とした。The invention according to claim 11 provides d), e),
The gist of the present invention is a method for improving soft ground characterized by repeating step f).
【００２３】請求項１２記載の発明は、圧密沈下後の地
盤の凹部内に撒き出す土砂が浚渫泥であることを特徴と
する軟弱地盤の改良工法をその要旨とした。The gist of the invention according to claim 12 is to provide an improved method of soft ground characterized in that the earth and sand scattered into the concave portion of the ground after consolidation settlement is dredge mud.
【００２４】請求項１３記載の発明は、各工程に使用さ
れる第１、第２の水平ト゛レーン材、第１、第２の排水材
及び可撓管のいずれか又は全てが、生分解性成形材料よ
りなることを特徴とする軟弱地盤の改良工法をその要旨
とした。According to a thirteenth aspect of the present invention, any or all of the first and second horizontal train members, the first and second drainage members, and the flexible pipe used in each step are formed by biodegradable molding. The gist is an improvement method for soft ground characterized by being made of a material.
【００２５】請求項１４記載の発明は、生分解性成形材
料が天然高分子を主体とすることを特徴とする軟弱地盤
の改良工法をその要旨とした。The gist of the invention of claim 14 is a method of improving soft ground, characterized in that the biodegradable molding material is mainly composed of a natural polymer.
【００２６】[0026]
（作用）請求項１〜８記載の軟弱地盤の改良工法にあっ
ては、地盤上面が、鉛直ト゛レーン材上端部及び通水材と
ともに気密シートで覆われるとともに、通水材に連結さ
れた真空ポンプが作動して真空引きされることから、地
盤上面は負圧の状態となり、地盤中における間隙水圧と
の間には差が生じるようになる。(Operation) In the method for improving soft ground according to claims 1 to 8, the upper surface of the ground is covered with an airtight sheet together with the upper end of the vertical train material and the water-permeable material, and the vacuum pump is connected to the water-permeable material. Is operated to be evacuated, so that the upper surface of the ground is in a negative pressure state, and a difference is generated between the pressure and the pore water pressure in the ground.
【００２７】そしてこの圧力差によって、鉛直ト゛レーン
材を上端部を残して地盤中に所定の間隔をおいて打設す
ることにより、地盤中に造成された鉛直排水壁を通して
地盤中の水と空気が地盤表面へと吸い出されるようにな
っている。地盤表面の水と空気は、鉛直ト゛レーン材上端
部と接触するように水平状に配された通水材を通って真
空タンクへと排出されるようになっている。[0027] By this pressure difference, the vertical train material is driven into the ground at predetermined intervals while leaving the upper end portion, so that water and air in the ground pass through the vertical drainage wall formed in the ground. It is designed to be sucked out to the ground surface. Water and air on the ground surface are discharged to the vacuum tank through a water-permeable material arranged horizontally so as to contact the upper end of the vertical train material.
【００２８】地盤中の水と空気が地盤表面へと吸い出さ
れると、地盤は水と空気が吸い出された分だけ圧密沈下
し、凹部が形成されることになる。この後、圧密沈下後
の凹部に土砂を撒き出す。これにより、地盤上には土砂
による圧密載荷重が加わり、地盤の圧密脱水はさらに進
行し、圧密沈下が促進することになる。When the water and air in the ground are sucked out to the surface of the ground, the ground consolidates and sinks by the amount of water and air sucked out, and a concave portion is formed. Thereafter, the earth and sand is scattered into the recess after the consolidation settlement. As a result, a consolidation load due to earth and sand is applied to the ground, and consolidation dewatering of the ground further proceeds, and consolidation settlement is promoted.
【００２９】また凹部内に撒き出された土砂層中の水及
び空気は、この土砂層に、前記気密シートを貫通して前
記砂層に至る深さまで鉛直ト゛レーン材を打設し、前記真
空ポンプを作動させて前記地盤上面に負圧の状態を造り
出すことで、前記鉛直ト゛レーン材を介して排出されるよ
うになっている。The water and the air in the sediment layer spouted into the recess are used to drive a vertical train material into the sediment layer so as to penetrate the airtight sheet and reach the sand layer. By actuating to create a negative pressure state on the ground surface, the ground is discharged through the vertical train material.
【００３０】そして上述の気密シート上への土砂の撒き
出し、土砂層への鉛直ト゛レーン材の打設、及び地盤上面
における負圧状態の造出といった操作を繰り返すことに
より、地盤及び土砂層は土砂層による圧密載荷重と負圧
力とによって圧密脱水が効果的に進行し、硬化地盤へと
改良されるようになっている。By repeating the above-described operations of dispersing the earth and sand on the airtight sheet, placing the vertical train material on the earth and sand layer, and creating a negative pressure state on the upper surface of the ground, the soil and the earth and sand layer are formed. The consolidation dehydration proceeds effectively by the consolidation load and the negative pressure by the layer, and is improved to a hardened ground.
【００３１】また、土砂層が浚渫泥によるものの場合に
は、上記圧密載荷重と負圧力とによる圧密脱水で、地盤
改良と同時に浚渫泥の処理も行うことができるようにな
っている。When the soil layer is made of dredged mud, the consolidation dewatering by the above-mentioned consolidation load and negative pressure enables the dredged mud to be treated simultaneously with the ground improvement.
【００３２】請求項９〜１５記載の軟弱地盤の改良工法
にあっては、圧密沈下後の地盤の凹部底面に、真空ポン
プと連結し、排水ポンプを備えた真空タンクと、同真空
タンクと接続した第１の排水材とが設置され、この第１
の排水材と接するように、所定の間隔をおいて第１の水
平ト゛レーン材が敷設され、当該凹部内に土砂が撒き出さ
れ、前記真空ポンプが作動して真空引きされることか
ら、真空タンク、第１の排水材及び第１の水平ト゛レーン
材を介して土砂層中の水及び空気が排出され、土砂層は
固化するようになる。また同時に、凹部内に撒き出され
た土砂層による圧密載荷重によって地盤の圧密脱水が効
果的に進行し、硬化地盤へと改良されるようになってい
る。In the method for improving soft ground according to the ninth to fifteenth aspects, a vacuum tank connected to a vacuum pump and connected to a vacuum pump is provided on the bottom surface of the concave portion of the ground after consolidation settlement, and the vacuum tank is connected to the vacuum tank. The first drainage material was installed, and this first drainage material was installed.
The first horizontal train material is laid at a predetermined interval so as to be in contact with the drainage material, and the earth and sand is scattered in the concave portion, and the vacuum pump is operated to be evacuated. Then, water and air in the sediment layer are discharged through the first drainage material and the first horizontal train material, and the sediment layer solidifies. At the same time, the consolidation dewatering of the ground proceeds effectively by the consolidation load of the earth and sand layer scattered in the concave portion, and the ground is improved to a hardened ground.
【００３３】土砂層の固化と軟弱地盤の硬化により圧密
沈下がさらに進行した凹部内（固化した土砂層の上面）
に、第２の排水材が設置され、この第２の排水材に接す
るように、所定の間隔をおいて第２の水平ト゛レーン材が
敷設され、前記第２の排水材と前記第１の排水材とが可
撓管を介して接続され、この凹部内に再度土砂が撒き出
され、前記真空ポンプが作動して真空引きされることか
ら、真空タンク、第１、第２の排水材及び第１、第２の
水平ト゛レーン材、可撓管を介して新たに撒き出された土
砂層中の水及び空気が排出され、土砂層は固化するよう
になる。また同時に、さきに撒き出された土砂層からの
水及び空気の排出も行われ、さらに凹部内に再度撒き出
された土砂層による圧密載荷重によって地盤の圧密脱水
が効果的に進行し、さらなる硬化地盤へと改良されるよ
うになっている。[0033] In a concave portion where consolidation settlement further progresses due to solidification of the soil layer and hardening of the soft ground (the upper surface of the solidified soil layer).
A second drain material is installed, and second horizontal train members are laid at predetermined intervals so as to be in contact with the second drain material, and the second drain material and the first drain material are laid. The material is connected via a flexible tube, the earth and sand is again scattered into the concave portion, and the vacuum pump is operated to be evacuated, so that the vacuum tank, the first and second drainage materials and the 1. The water and air in the newly spouted sediment layer are discharged through the second horizontal train material and the flexible tube, and the sediment layer solidifies. At the same time, water and air are discharged from the sediment layer that has been scattered earlier, and the consolidation load of the soil layer that has been scattered again in the concave portion effectively consolidates and dewaters the ground. It has been improved to hardened ground.
【００３４】尚、軟弱地盤の含水量（軟弱さ）によって
は、上記固化した土砂上面に、第３、第４、第５・・・
の排水材の設置、第３、第４、第５の水平ト゛レーン材の
敷設、凹部内への土砂の撒き出し、真空ポンプによる土
砂層中の水分及び空気の除去といった操作を繰り返すこ
とで、より効果的でかつ確実な地盤の改良がなされるよ
うになる。Depending on the water content (softness) of the soft ground, the third, fourth, fifth,...
By repeating the operation of installing drainage material, laying the third, fourth, and fifth horizontal train materials, dispersing earth and sand in the recess, and removing water and air in the earth and sand layer by the vacuum pump, Effective and reliable ground improvement will be achieved.
【００３５】また、土砂層が浚渫泥によるものの場合に
は、上記圧密載荷重と負圧力とによる圧密脱水で、地盤
改良と同時に浚渫泥の処理も行うことができるようにな
っている。When the soil layer is made of dredged mud, the consolidation dewatering by the above-mentioned consolidation load and negative pressure enables the dredged mud to be treated simultaneously with the ground improvement.
【００３６】尚、上記請求項９〜１４記載の工法におい
ては、真空タンクとして排水ポンプを備えたものを採用
している。これは、圧密による地盤の沈下が大きくて
も、凹部内に設置した真空タンク（排水ポンプ）の稼働
により真空度ロスが軽減できるようにするためである。
すなわち、図１３〜図１５に示すように、圧密による地
盤Ａの沈下に伴って真空タンク３２も沈下することにな
る。真空タンク３２の沈下に伴い、本来負圧発生手段で
ある真空ポンプ４０は、沈下した深さ（高さ）分だけ、
地盤間隙水を揚水しなければならなくなる。そして、そ
の揚水に真空ポンプ４０の負圧力が利用され、その結果
として真空ポンプ４０による負圧能力も低下することに
なるのである。このような不具合が発生することがない
よう、本発明では、排水ポンプを備えた真空タンク３２
を採用し、これにより真空タンク３２内の間隙水が、常
時、排水ポンプの稼働によって排水されて、真空ポンプ
４０の真空度ロスを軽減しているのである。In the construction method according to the ninth to fourteenth aspects, a vacuum tank equipped with a drainage pump is employed. This is because even if the settlement of the ground due to consolidation is large, the loss of the degree of vacuum can be reduced by operating the vacuum tank (drain pump) installed in the concave portion.
That is, as shown in FIGS. 13 to 15, the vacuum tank 32 also sinks with the settlement of the ground A due to the consolidation. With the sinking of the vacuum tank 32, the vacuum pump 40, which is originally a negative pressure generating means, moves by the sinking depth (height).
The ground pore water must be pumped. Then, the negative pressure of the vacuum pump 40 is used for the pumping, and as a result, the negative pressure capability of the vacuum pump 40 is also reduced. In order to prevent such a problem from occurring, the present invention provides a vacuum tank 32 having a drain pump.
Thus, the interstitial water in the vacuum tank 32 is constantly drained by the operation of the drain pump to reduce the loss of vacuum degree of the vacuum pump 40.
【００３７】以下、本発明の軟弱地盤の改良工法（以下
単に改良工法という）を図面に示した一実施例に従って
詳細に説明する。尚、図１〜図１５に示す実施例は、湖
沼周囲の軟弱地盤の改良例を図示したものであり、同改
良例では、地盤上に撒き出す土砂として湖沼からの浚渫
泥を用いることで、軟弱地盤の改良と同時に湖沼からの
浚渫泥の処理も行っている。Hereinafter, the method for improving soft ground of the present invention (hereinafter simply referred to as “improvement method”) will be described in detail with reference to an embodiment shown in the drawings. The embodiment shown in FIGS. 1 to 15 illustrates an improved example of soft ground around a lake, and in the improved example, dredging mud from a lake is used as soil to be scattered on the ground. At the same time as improving the soft ground, we are also treating dredged mud from lakes and marshes.
【００３８】図１〜図１１には、請求項１〜８記載の発
明の改良工法の実施例を示した。請求項１記載の改良工
法は、以下のａ）〜ｈ）の工程を有することを特徴とす
るものである。図１に示すように、ａ）の工程、すなわ
ち地盤中に鉛直排水壁を造成する工程は、鉛直ト゛レーン
材１１を上端部１１ａを残して地盤Ａ中に所定の間隔を
おいて打設することからなる。鉛直ト゛レーン材１１とし
ては、従来より使用されているドレーン材を用いること
ができる。その中でもプラスチックドレーン材は、図１
に示すように、マンドレル１２に内挿した状態で地盤Ａ
中に貫入し、プラスチックドレーン材１１を地盤Ａに残
したままマンドレル１２を引き上げることで打設するこ
とができ、打設作業の容易さ、目詰まりが生じ難く、確
実な透水材としての機能をもつことから好ましく、本実
施例ではこのドレーン材を採用している。FIGS. 1 to 11 show an embodiment of the improved method according to the first to eighth aspects of the present invention. The improved method according to the first aspect is characterized by including the following steps a) to h). As shown in FIG. 1, in the step a), that is, in the step of forming a vertical drainage wall in the ground, the vertical train material 11 is cast into the ground A at a predetermined interval while leaving the upper end portion 11a. Consists of A conventionally used drain material can be used as the vertical drain material 11. Among them, plastic drain material is shown in Fig. 1.
As shown in FIG.
The mandrel 12 can be poured by penetrating into the ground and pulling up the mandrel 12 while leaving the plastic drain material 11 on the ground A, so that the driving work is easy, the clogging hardly occurs, and the function as a reliable water permeable material is achieved. In this embodiment, this drain material is employed.
【００３９】この鉛直ト゛レーン材１１を地盤Ａ中に所定
の間隔をおいて打設することで、地盤Ａ中には所定の間
隔をおいて鉛直状の排水壁が造成されることになり、各
排水壁間の地盤中に含まれる水及び空気は、図１中矢印
で示すように鉛直ト゛レーン材１１よりなる排水壁を通し
て地盤Ａ上面へと吸い上げられ、地盤Ａ上面に残されて
いるドレーン材上端部１１ａより排出される。By placing the vertical train material 11 in the ground A at predetermined intervals, vertical drainage walls are formed in the ground A at predetermined intervals. Water and air contained in the ground between the drainage walls are sucked up to the upper surface of the ground A through the drainage wall composed of the vertical train material 11 as shown by arrows in FIG. It is discharged from the unit 11a.
【００４０】次に、ｂ）の工程、すなわち、真空ポンプ
に連結した通水材を配置する。図２に示すように、ドレ
ーン材上端部１１ａは地盤Ａの上面に突出している。こ
の突出部分に通水材１３を接触するように平行状に配置
するのである。通水材１３としては、水及び空気が該通
水材１３の長手方向へと移動できる通路としての機能を
持つものならば何でもよいが、地盤Ａ側からの水及び空
気が該通水材１３内部へ侵入する口、例えば孔、スリッ
トなどが、地盤Ａ中の砂や土砂などによって閉塞してし
まい、水及び空気の通水材内部への侵入が困難となった
り、同じく地盤中の砂や土砂などによって通路が閉塞し
て水及び空気が該通水材の長手方向へ移動できなかった
りすることが少ない構造のものが好ましい。Next, step b), that is, a water-permeable material connected to a vacuum pump is arranged. As shown in FIG. 2, the drain material upper end 11 a protrudes from the upper surface of the ground A. The water-permeable material 13 is arranged in parallel so as to come into contact with the projecting portion. As the water passage material 13, any material having a function as a passage through which water and air can move in the longitudinal direction of the water passage material 13 may be used. The openings, such as holes and slits, that enter the interior are blocked by sand, earth and sand, etc. in the ground A, making it difficult for water and air to enter the water-permeable material. It is preferable to use a structure in which water and air are less likely to move in the longitudinal direction of the water-permeable material due to the passage being blocked by soil and the like.
【００４１】具体的には図３に示すように、プラスチッ
クネット１４とその表面に積層した繊維シート１５とか
らなるものが好ましい例として挙げられる。この通水材
１３において水及び空気は、プラスチックネット１４の
表面に積層した繊維シート１５側から侵入し、プラスチ
ックネット１４と繊維シート１５との隙間、及び繊維シ
ート１５の構成繊維相互間を通して移動するようにな
る。More specifically, as shown in FIG. 3, a preferred example is one comprising a plastic net 14 and a fiber sheet 15 laminated on the surface thereof. In the water-permeable material 13, water and air enter from the side of the fiber sheet 15 laminated on the surface of the plastic net 14 and move through the gap between the plastic net 14 and the fiber sheet 15 and between the constituent fibers of the fiber sheet 15. Become like
【００４２】この通水材１３の一端側には真空ポンプ１
６が連結されている。図２に示すように、真空ポンプ１
６は通水材１３の一端側に直接連結されず、真空タンク
１７を介している。つまり真空ポンプ１６からの負圧が
排水ポンプ（図示しない）を備える真空タンク１７を介
して通水材１３へと伝達されるようになっている。そし
てこの作用により水及び空気が通水材１３へと入り込
み、同通水材１３内を移動して真空タンク１７へと排出
され、排水ポンプ（図示しない）によってタンク１７外
へ排出されるようになっているのである。A vacuum pump 1 is provided at one end of the water passage material 13.
6 are connected. As shown in FIG.
Numeral 6 is not directly connected to one end of the water-passing material 13 but via a vacuum tank 17. That is, the negative pressure from the vacuum pump 16 is transmitted to the water passage material 13 via the vacuum tank 17 having a drain pump (not shown). By this action, water and air enter the water passage material 13, move inside the water passage material 13, are discharged to the vacuum tank 17, and are discharged to the outside of the tank 17 by a drain pump (not shown). It is becoming.
【００４３】次いで、ｃ）、ｄ）の工程を行う。つまり
図４に示すように、鉛直ト゛レーン材１１の上端部１１ａ
及び通水材１３を砂層２１で覆い、地盤Ａ上を前記鉛直
ト゛レーン材１１の上端部１１ａ、通水材１３及び砂層２
１とともに気密シート１８で覆うのである。ここで気密
シート１８は、空気が透過できない素材であるならば、
合成樹脂シート、繊維基材表面に合成樹脂フィルムをラ
ミネートしたものなど何でもよい。Next, steps c) and d) are performed. That is, as shown in FIG. 4, the upper end portion 11a of the vertical train
And the water-permeable material 13 is covered with a sand layer 21, and the upper end 11 a of the vertical train material 11, the water-permeable material 13 and the sand layer 2 are covered on the ground A.
1 together with the airtight sheet 18. Here, if the airtight sheet 18 is made of a material through which air cannot pass,
Any material may be used, such as a synthetic resin sheet or a laminate of a synthetic resin film on the surface of a fiber substrate.
【００４４】次いで、ｅ）の工程、すなわち気密シート
１８で地盤Ａ上を覆った状態で真空ポンプ１６を作動さ
せるのである。真空ポンプ１６が作動すると、真空ポン
プ１６からの負圧が排水ポンプを備える真空タンク１７
を介して通水材１３へと伝達され、地盤Ａ上面は負圧状
態となり、地盤Ａ中における間隙水圧との間には差が生
じるようになる。Then, the vacuum pump 16 is operated in the step e), that is, while the ground A is covered with the airtight sheet 18. When the vacuum pump 16 is operated, the negative pressure from the vacuum pump 16 is applied to a vacuum tank 17 having a drain pump.
And the upper surface of the ground A is in a negative pressure state, and a difference is generated between the upper surface of the ground A and the pore water pressure in the ground A.
【００４５】そしてこの圧力差によって、地盤Ａ中に造
成された鉛直排水壁を通して地盤Ａ中の水と空気が、図
４中矢印で示したように、地盤Ａ表面へと吸い出され、
地盤表面の水と空気は、鉛直ト゛レーン材上端部１１ａと
接触するように水平状に配された通水材１３を通って真
空タンク１７へと排出されるようになる。Then, due to this pressure difference, water and air in the ground A are sucked out to the surface of the ground A as shown by arrows in FIG.
The water and air on the ground surface are discharged to the vacuum tank 17 through the water-passing material 13 arranged horizontally so as to contact the upper end portion 11a of the vertical train material.
【００４６】真空ポンプ１６は勿論連続して作動させて
もよいが、間欠的に作動させることもできる。図５に示
すように、地盤Ａ表面が負圧の状態となり、その圧力差
によって地盤Ａ中の水と空気が地盤Ａ表面へと吸い出さ
れると、地盤、特に鉛直ト゛レーン材１１の周りは、地盤
Ａを構成する粒子間隙が狭くなり、水と空気が通り難く
なる。この結果、地盤Ａ中に残存する水と空気は、圧力
差によっても十分に吸い出されなくなる。The vacuum pump 16 may be operated continuously, but may be operated intermittently. As shown in FIG. 5, when the surface of the ground A is in a negative pressure state, and the water and the air in the ground A are sucked out to the surface of the ground A due to the pressure difference, the ground, especially around the vertical train material 11, The gap between the particles constituting the ground A becomes narrow, and it becomes difficult for water and air to pass through. As a result, the water and air remaining in the ground A cannot be sufficiently sucked even by the pressure difference.
【００４７】真空ポンプを間欠的に作動させることで、
地盤Ａ上面は常圧及び負圧の状態が交互に造り出される
ことになる。負圧の状態から常圧の状態へと変わるとき
には、空気が一気に入り込むことになる。このため、地
盤Ａにはその圧力差によって空気が一気に入り込むこと
になり、このときの衝撃力が地盤Ａに作用して地盤Ａを
揺り動かし、この結果図６に示すように地盤Ａ、特に鉛
直ト゛レーン材１１周りの地盤Ａを構成する粒子間隙は広
がり、水と空気は通り易くなる。By operating the vacuum pump intermittently,
On the upper surface of the ground A, a state of normal pressure and a state of negative pressure are alternately created. When the state changes from a negative pressure state to a normal pressure state, the air becomes completely entrapped. Due to this pressure difference, the air is forced into the ground A, and the impact force at this time acts on the ground A to shake the ground A. As a result, as shown in FIG. The gap between the particles constituting the ground A around the material 11 is widened, and the water and the air pass easily.
【００４８】そこで、再び真空ポンプ１６を作動させる
ことで、地盤Ａ表面が常圧の状態から負圧の状態へと変
わることで、その圧力差によって地盤Ａ中の水と空気が
吸い出されるようになる。このように真空ポンプを間欠
的に作動させることで、地盤中の水と空気はより効率的
に吸い出されることになる。Then, by operating the vacuum pump 16 again, the surface of the ground A changes from a normal pressure state to a negative pressure state, so that the water and the air in the ground A are sucked out by the pressure difference. become. By intermittently operating the vacuum pump in this manner, water and air in the ground are more efficiently sucked.
【００４９】また真空ポンプを間欠的に作動させること
で、地盤Ａ上面に常圧及び負圧の状態を交互に造り出す
場合、負圧の状態から常圧の状態へと変わるときに、圧
力差によって空気が一気に入り込むだけではなく、さら
に積極的に空気を送り込むようにすることもできる。こ
の場合には、地盤に作用する衝撃力もより大きくなり、
地盤、特に鉛直ト゛レーン材１１周りの地盤Ａを構成する
粒子間隙はより大きく広がり、水と空気はより通り易く
なる。When the vacuum pump is operated intermittently to alternately create a normal pressure state and a negative pressure state on the upper surface of the ground A, when the state changes from the negative pressure state to the normal pressure state, a pressure difference is generated. Not only can air be loved, but air can be sent more actively. In this case, the impact force acting on the ground becomes larger,
The space between the particles constituting the ground, particularly the ground A around the vertical train material 11, is larger and the water and the air are easier to pass through.
【００５０】この結果、より効果的に地盤中の水と空気
の吸い出しができると共に、地盤上面をより速く常圧の
状態へと戻すことができる。As a result, water and air in the ground can be sucked out more effectively, and the upper surface of the ground can be returned to a normal pressure state more quickly.
【００５１】また、地盤Ａを揺り動かす別の方法として
は、鉛直ト゛レーン材１１自体を振動させる方法がある。
この場合も地盤Ａ、特に鉛直ト゛レーン材１１周りの地盤
を構成する粒子間隙は広がり、水と空気は通り易くな
る。尚、鉛直ト゛レーン材を振動させる方法と前述の真空
ポンプを間欠的に作動させる方法を併用したならば、よ
り効果的に地盤Ａ中の水及び空気の吸い出しを行うこと
ができる。As another method of shaking the ground A, there is a method of vibrating the vertical train material 11 itself.
Also in this case, the gap between the particles constituting the ground A, particularly the ground around the vertical train material 11, is widened, and water and air can easily pass through. If the method of vibrating the vertical train material and the method of intermittently operating the above-described vacuum pump are used together, the water and air in the ground A can be more effectively sucked out.
【００５２】上述の如く地盤Ａ中の水と空気が地盤Ａ表
面へと吸い出されることで、地盤Ａは、図７に示すよう
に水と空気が吸い出された分だけ圧密沈下し、ここに凹
部３０が造り出されることになる。As described above, the water and the air in the ground A are sucked out to the surface of the ground A, so that the ground A consolidates and sinks by an amount corresponding to the sucked water and air as shown in FIG. The concave portion 30 is created in the first step.
【００５３】この後、Ｆ）の工程を行う。すなわち図８
に示すように、前記軟弱地盤Ａの圧密沈下により造られ
た凹部３０内に土砂２２を撒き出す。これにより、地盤
Ａ上には土砂２２よりなる層によって圧密載荷重が加わ
り、さらに地盤Ａの圧密脱水が行われるようになる。
尚、土砂２２を撒き出す場合、土砂２２が周囲に広がら
ないように、改良区域を取り囲むように壁を設けておい
てもよい。Thereafter, the step F) is performed. That is, FIG.
As shown in FIG. 5, earth and sand 22 are scattered in a recess 30 formed by consolidation settlement of the soft ground A. As a result, a consolidation load is applied on the ground A by the layer of the earth and sand 22, and the consolidation dewatering of the ground A is performed.
When the earth and sand 22 are scattered, a wall may be provided so as to surround the improvement area so that the earth and sand 22 do not spread around.
【００５４】次に、ｇ）の工程、すなわち図９に示す如
く、前記土砂２２よりなる層中に前記気密シート１８を
貫通して前記砂層２１に至る深さまで鉛直ト゛レーン材２
４を打設するのである。この場合、鉛直ト゛レーン材２４
の打設は、前述の鉛直ト゛レーン材１８の打設と同じ要領
で行う。そして、ｈ）の工程、つまり前記真空ポンプ１
６を作動させるのである。これにより真空ポンプ１６か
らの負圧が真空タンク１７を介して通水材１３へと伝達
され、地盤Ａ上面は負圧状態となる。地盤Ａ上面の負圧
力は、砂層２１中の前記通水材１３に上端部１１ａが接
触する地盤Ａ中の鉛直ト゛レーン材１８とともに、砂層２
１中に打ち込まれた鉛直ト゛レーン材２４にも伝わり、こ
れら鉛直ト゛レーン材１８、２４を介して、地盤Ａ及び土
砂２２よりなる層中の水及び空気が排出されるようにな
る。Next, in the step g), as shown in FIG. 9, the vertical train material 2 penetrates through the hermetic sheet 18 into the sand layer 21 to a depth reaching the sand layer 21 in the layer made of the earth and sand 22.
4 is cast. In this case, the vertical train material 24
Is carried out in the same manner as the above-described placement of the vertical train 18. And step h), that is, the vacuum pump 1
6 is activated. As a result, the negative pressure from the vacuum pump 16 is transmitted to the water passage material 13 via the vacuum tank 17, and the upper surface of the ground A is in a negative pressure state. The negative pressure on the upper surface of the ground A is caused by the vertical train material 18 in the ground A where the upper end 11a contacts the water-permeable material 13 in the sand layer 21 and the sand layer 2
The water and the air in the layer consisting of the ground A and the earth and sand 22 are discharged through the vertical train members 18 and 24 which are also transmitted to the vertical train members 24 driven into the inside.
【００５５】尚、図９に示す態様では、土砂２２よりな
る層の上面に砂層２１を覆う気密シート１８と同じ気密
シート２５で覆われており、これにより真空ポンプ１６
からの負圧力が確実に土砂２２よりなる層中に伝わり、
より効果的な脱水が行えるようになっている。In the embodiment shown in FIG. 9, the upper surface of the layer composed of the earth and sand 22 is covered with the same air-tight sheet 25 as the air-tight sheet 18 covering the sand layer 21.
The negative pressure from is surely transmitted to the layer consisting of earth and sand 22,
More effective dehydration can be performed.
【００５６】次いで図１０に示すように、図８及び図９
に示す土砂２２の撒き出し、鉛直ト゛レーン材２４の砂層
２１への打設、及び真空ポンプ１６からの負圧力による
排水によって地盤Ａ及び土砂２２よりなる層の圧密沈下
が生じた後、再度上述の気密シート２５上への土砂の撒
き出し、土砂層への鉛直ト゛レーン材の打設、及び地盤上
面における負圧状態の造出といった操作を繰り返すので
ある。これにより、地盤及び土砂層は土砂による圧密載
荷重と負圧力とによって圧密脱水が効果的に進行し、硬
化地盤へと改良されるようになる。Next, as shown in FIG. 10, FIGS.
After the soil A and the soil composed of the soil A and the layer made of the soil 22 are caused by the dispersal of the earth and sand 22, the placement of the vertical train material 24 into the sand layer 21, and the drainage by the negative pressure from the vacuum pump 16, as described above. Operations such as dispersal of earth and sand on the airtight sheet 25, placement of a vertical train material on the earth and sand layer, and creation of a negative pressure state on the ground surface are repeated. Thereby, the consolidation dewatering of the ground and the earth and sand layer is effectively progressed by the consolidation load and the negative pressure due to the earth and sand, and the soil and the soil are improved to the hardened ground.
【００５７】尚、各工程に使用される鉛直ト゛レーン材、
通水材及び気密シートのいずれか又は全てを生分解性成
形材料により構成することもできる。生分解性成形材料
とは土中又は水中に存在する微生物や水分などにより容
易に分解してしまう材料をいう。この生分解性成形材料
によって構成された鉛直ト゛レーン材、通水材及び気密シ
ートを用いて、上述の方法に従い改良工法を施工した場
合、鉛直ト゛レーン材、通水材及び気密シートを構成する
生分解性成形材料が、地盤内の土中又は水中に存在する
微生物や水分などにより容易に分解してしまうため、こ
れらの部材を撤去する必要がなく、軟弱地盤の改良に要
する費用と手間とを大幅に削減することができる。The vertical train material used in each step,
Any or all of the water-permeable material and the airtight sheet may be made of a biodegradable molding material. The biodegradable molding material refers to a material which is easily decomposed by microorganisms or water existing in soil or water. When a vertical train material, a water-permeable material, and an airtight sheet are constructed using the biodegradable molding material and the improved construction method is applied in accordance with the above-described method, the biodegradation forming the vertical train material, the water-permeable material, and the airtight sheet Since the flexible molding material is easily decomposed by microorganisms and water present in the soil or water in the ground, there is no need to remove these members, greatly reducing the cost and labor required for improving the soft ground. Can be reduced.
【００５８】また生分解性成形材料としては、芋類、米
麦類、コーン類などの澱粉質、澱粉に酢酸ビニルなどの
ビニルモノマーを共重合させた澱粉質誘導体、パルプ、
セルロースなどの植物繊維又は植物粉末、天然ゴム、ア
ラビアゴムなどの植物性高分子、ガゼイン、ゼラチン、
グルテンなどの動物性タンパク質といった天然高分子を
主体とするものが好ましい。というのは、これら天然高
分子を主体とするものにあっては、施工後に地盤内で分
解しても環境に悪影響を与えることがないからである。Examples of the biodegradable molding material include starches such as potatoes, rice and wheat, corns, starchy derivatives obtained by copolymerizing starch with a vinyl monomer such as vinyl acetate, pulp, and the like.
Plant fibers or plant powders such as cellulose, natural rubber, vegetable polymers such as gum arabic, casein, gelatin,
Those mainly composed of natural polymers such as animal proteins such as gluten are preferred. This is because, in the case of these natural polymer-based materials, even if they are decomposed in the ground after construction, they do not adversely affect the environment.
【００５９】尚、本発明の軟弱地盤の改良工法を施工し
た後（地盤を十分に減圧した後）、必要に応じて前記砂
層にセメント粉末またはセメントミルクを、地盤の減圧
様態を利用して注入すれば、砂層の液状化を防止するこ
とができる。After the soft ground improvement method of the present invention is applied (after the ground is sufficiently depressurized), if necessary, cement powder or cement milk is injected into the sand layer by utilizing the depressurized state of the ground. Then, liquefaction of the sand layer can be prevented.
【００６０】尚、本発明の軟弱地盤の改良工法を、埋立
造成区域などの軟弱地盤に適用する場合、埋立造成時に
は、埋立造成区域の周囲を浚渫することから、その際に
生じる浚渫泥を気密シート上に撒き出す土砂とすればよ
い。これにより、軟弱地盤の改良と浚渫泥の処理とが同
時に行えるようになる。また、河川や港湾などの浚渫工
事の際に生じた浚渫泥を、本発明の地盤改良工法を適用
するときに、気密シート上に投入される圧密載荷重（土
砂）として用いることもできる。When the method for improving soft ground of the present invention is applied to soft ground such as a landfill area, the land around the landfill area is dredged during landfill, and the dredging mud generated at that time is hermetically sealed. It may be earth and sand to be scattered on the sheet. Thereby, improvement of soft ground and treatment of dredging mud can be performed simultaneously. In addition, when applying the ground improvement method of the present invention, dredging mud generated at the time of dredging work of a river or a harbor can be used as a consolidation load (sediment) loaded on an airtight sheet.
【００６１】尚、上に示したものは単なる説明例にすぎ
ず、例えば鉛直ト゛レーン材１１の上端部１１ａと通水材
１３との位置が施工時にズレてしまわないように、これ
らに固定手段を設けたりするなど、特許請求の範囲に記
載された範囲で自由に変更することができる。The above is merely an illustrative example. For example, a fixing means is provided on the vertical train 11 so that the upper end 11a of the vertical train 11 and the water-permeable material 13 do not shift during construction. For example, it can be freely changed within the scope described in the claims.
【００６２】次に、請求項９〜１５記載の発明の改良工
法を説明する。この発明の実施例を図１２〜図１５に示
した。この改良工法は、以下のａ）〜ｆ）の工程を有す
ることを特徴とするものである。まず最初に、ａ）の工
程について説明する。ａ）の工程では、図１２及び図１
３に示すように、圧密沈下後の地盤Ａの凹部３０底面
に、真空ポンプ４０と連結した真空タンク３２（水中ポ
ンプ内蔵、以下同様）と、この真空タンク３２と接続し
た第１の排水材３３ａとを設置すると共に、この第１の
排水材３３ａと接するように、所定の間隔をおいて第１
の水平ト゛レーン材３４ａを敷設する。尚、この例におい
て、真空タンク３２は、図１２に示すように凹部３０底
面のほぼ中央に設置した。これは、通常、中央部が最も
沈下量が大きくなるからである。Next, an improved method according to the present invention will be described. Embodiments of the present invention are shown in FIGS. This improved method has the following steps a) to f). First, the step a) will be described. In the step a), FIG. 12 and FIG.
As shown in FIG. 3, a vacuum tank 32 (built-in submersible pump, the same applies hereinafter) connected to a vacuum pump 40 and a first drainage material 33a connected to the vacuum tank 32 are provided on the bottom surface of the concave portion 30 of the ground A after consolidation settlement. And the first drainage member 33a is contacted with the first drainage member 33a at a predetermined interval.
Is laid. In this example, the vacuum tank 32 was installed substantially at the center of the bottom surface of the recess 30 as shown in FIG. This is because the sinking amount is usually largest in the central part.
【００６３】尚、ここで軟弱地盤を圧密沈下させて、地
盤に凹部を造成する方法は、地盤中に鉛直ト゛レーン材を
打設し、この地盤上に土砂などの加重を載加して地盤中
の水を圧密脱水する方法や真空圧密脱水による方法な
ど、まったく任意である。本実施例では、前述の図１〜
図７に示す工法を用いた。又、本例では、図１〜図７に
示す工法で用いた真空ポンプ１６を、そのまま本工法の
真空ポンプ４０として利用した。尚、地盤の沈下量、即
ち凹部３０の深さとしては、１ｍ以上が好ましい。Here, a method of forming a concave portion in the ground by consolidating the soft ground to form a depression in the ground is performed by placing a vertical train material in the ground and placing a load such as earth and sand on the ground. Any method such as a method of consolidating and dewatering the water or a method of vacuum consolidation dehydration is possible. In the present embodiment, FIGS.
The method shown in FIG. 7 was used. In this example, the vacuum pump 16 used in the method shown in FIGS. 1 to 7 was used as it is as the vacuum pump 40 of the present method. Note that the amount of subsidence of the ground, that is, the depth of the concave portion 30 is preferably 1 m or more.
【００６４】この例において、真空タンク３２と真空ポ
ンプ４０とは、耐圧ホース４１を介して連結されてい
る。また第１の排水材３３ａには、多数の孔（図示しな
い）を有する管体であり、その周面には不織布などの繊
維シートが張り付けられて孔及び管の目詰まりを防止し
ているものを用いた。図１２及び図１３の例では、凹部
３０底部の長さ方向に間隔をおいて３本の第１の排水材
３３ａを配置したが、凹部の大きさや深さに応じて、複
数本縦方向に並設したり、縦横格子状に配したり、ある
いは上部及び下部に平行して配置したりすることもでき
る。In this example, the vacuum tank 32 and the vacuum pump 40 are connected via a pressure-resistant hose 41. The first drainage member 33a is a tubular body having a large number of holes (not shown), and a fibrous sheet such as a nonwoven fabric is adhered to a peripheral surface thereof to prevent the holes and the tubes from being clogged. Was used. In the examples of FIGS. 12 and 13, the three first drainage members 33a are arranged at intervals in the length direction of the bottom of the concave portion 30. However, depending on the size and depth of the concave portion, a plurality of first drainage members 33a are arranged in the vertical direction. They may be arranged side by side, arranged in a vertical and horizontal lattice, or arranged in parallel at the top and bottom.
【００６５】また凹部３０の底部には、前記第１の排水
材３３ａに接触するように、第１の水平ドレーン材３４
ａを所定の間隔、好ましくは０．７〜１．０ｍの間隔を
置いて敷設する。この第１の水平ドレーン材３４ａは、
幅が１０〜３０ｃｍの帯状をなしており、プラスチック
ネットとその両表面に積層した繊維シートとからなり、
後述する土砂層内の水分及び空気が、プラスチックネッ
トと繊維シートとの間隙、繊維シートを構成する繊維間
隙を通して侵入し、かつ移動するようにしたもの（尚、
繊維シートには、不織布、織物、編物、紙などを用いる
ことができる。）、あるいは同じく樹脂ネットを用い、
このプラスチックネットの一方面側のみに繊維シートを
積層一体化したものなどを適用することができる。尚、
第１の水平ドレーン材３４ａ相互の間隔は、土質定数に
従って適宜変更する。The first horizontal drain member 34 is provided at the bottom of the recess 30 so as to contact the first drain member 33a.
a is laid at a predetermined interval, preferably 0.7 to 1.0 m. This first horizontal drain material 34a is
It is in the form of a belt with a width of 10 to 30 cm, and consists of a plastic net and a fiber sheet laminated on both surfaces thereof,
Moisture and air in the earth and sand layer to be described later enter and move through the gap between the plastic net and the fiber sheet and the fiber gap constituting the fiber sheet (in addition,
Nonwoven fabric, woven fabric, knitted fabric, paper, and the like can be used for the fiber sheet. ) Or, similarly, using a resin net,
A plastic net in which a fiber sheet is laminated and integrated only on one side of the plastic net can be used. still,
The distance between the first horizontal drain members 34a is appropriately changed according to the soil constant.
【００６６】図１２及び図１３に示すように、第１の水
平ドレーン材３４ａは、縦横に０．７〜１．０ｍの間隔
で格子状に配列して、各交差点を止め金（図示しない）
で止めて固定した網目状として用いることもできる。As shown in FIGS. 12 and 13, the first horizontal drain members 34a are arranged in a grid pattern at intervals of 0.7 to 1.0 m vertically and horizontally, and clasps (not shown) are provided at each intersection.
It can also be used as a mesh that is fixed by stopping at
【００６７】尚、水平ドレーン材３４ａは、凹部３０底
部にのみ配されているだけでも良いが、凹部３０の底部
及びその周辺部分にも敷設して、同水平ドレーン材３４
ａで凹部３０（撒き出される土砂層３５）の全体を取り
囲むようにすることもできる。この場合、凹部３０内に
撒き出される土砂層３５が、底部のみならず、その周辺
部からも水分及び空気の吸い出しが行われることにな
り、より効率的な水分及び空気の除去ができる。The horizontal drain member 34a may be disposed only at the bottom of the concave portion 30. However, the horizontal drain member 34a is also laid at the bottom of the concave portion 30 and its peripheral portion.
It is also possible to surround the entire concave portion 30 (the spouted soil layer 35) with a. In this case, the earth and sand layer 35 scattered in the concave portion 30 sucks moisture and air not only from the bottom but also from the periphery thereof, so that moisture and air can be more efficiently removed.
【００６８】この第１の水平ドレーン材３４ａと前記第
１の排水材３３ａとは、例えば排水材３３ａ上に第１の
水平ドレーン材３４ａを直接接続する態様を採ることが
できる。この場合、第１の排水材３３ａと第１の水平ド
レーン材３４ａは、単に積層状態としておいても良い
が、止め金（図示しない）などで相互を固定しておいて
も良い。また、第１の水平ドレーン材３４ａを敷設して
おき、この上に排水材３３ａを配置し、この上に砂の層
１３を設けるという態様も採ることもできる。The first horizontal drain member 34a and the first drainage member 33a can take a form in which the first horizontal drain member 34a is directly connected to the drainage member 33a, for example. In this case, the first drainage member 33a and the first horizontal drain member 34a may be simply laminated, but may be fixed to each other by a stopper (not shown) or the like. Further, a mode in which the first horizontal drain member 34a is laid, the drainage member 33a is disposed thereon, and the sand layer 13 is provided thereon may be employed.
【００６９】次に、前記凹部３０内に土砂３５を撒き出
す。土砂３５の撒き出しにより、地盤Ａ上には土砂３５
による圧密載荷重が加わり、さらに地盤Ａの圧密脱水が
行われるようになる。この土砂３５の撒き出し量、換言
すれば土砂３５よりなる層の厚さは任意である。土砂層
の厚さが薄ければ、処理は速いものの、１回の処理量は
少なくなり、土砂層の厚さが厚ければ、処理は遅くなる
ので、必要な処理量を考慮して適宜決定すると良い。具
体的には１〜２ｍの厚さが好ましい。Next, earth and sand 35 are scattered in the recess 30. By discharging the soil 35, the soil 35
And the consolidation load is applied, and consolidation dewatering of the ground A is further performed. The spreading amount of the earth and sand 35, in other words, the thickness of the layer made of the earth and sand 35 is arbitrary. If the thickness of the earth and sand layer is thin, the processing is fast, but the amount of one processing is small, and if the thickness of the earth and sand layer is thick, the processing is slow. Good. Specifically, a thickness of 1 to 2 m is preferable.
【００７０】次に、前記土砂層上面を気密シート３６で
覆う。気密シートとしては、空気が透過できない素材で
あるならば、合成樹脂シート、繊維シート表面に合成樹
脂フィルムをラミネートしたものなど何でも良い。この
気密シート３６で、土砂層上面を覆うことで、凹部３０
内は気密状態となり、より効率的な排水がなされるよう
になる。Next, the upper surface of the earth and sand layer is covered with an airtight sheet 36. The airtight sheet may be any material such as a synthetic resin sheet or a fiber sheet laminated with a synthetic resin film on the surface, as long as it is a material through which air cannot pass. By covering the upper surface of the earth and sand layer with this airtight sheet 36, the recess 30
The inside is airtight, and more efficient drainage is performed.
【００７１】この後、ｅ）の工程、すなわち真空ポンプ
４０を作動させる。これにより、真空ポンプ４０からの
負圧が真空タンク３２を介して第１の排水材３３ａに伝
わり、この第１の排水材３３ａに接続する第１の水平ド
レーン材３４ａを通して土砂層内の水分及び空気が、図
１３中矢印で示すように、第１の水平ドレーン材３４ａ
へと吸い出され、第１の排水材３３ａ、真空タンク３
２、耐圧ホース４１を介して排水され、土砂層が固化す
るようになっている。Thereafter, the step e), that is, the vacuum pump 40 is operated. Thereby, the negative pressure from the vacuum pump 40 is transmitted to the first drainage member 33a via the vacuum tank 32, and the moisture and the water in the sediment layer are passed through the first horizontal drain member 34a connected to the first drainage member 33a. As shown by an arrow in FIG. 13, air flows through the first horizontal drain material 34a.
To the first drainage material 33a, the vacuum tank 3
2. The water is drained through the pressure hose 41 so that the earth and sand layer is solidified.
【００７２】次に、ｉ）の工程、すなわち図１４に示す
ように、前記固化した土砂３５よりなる層上面に、第２
の排水材３３ｂを設置し、この第２の排水材３３ｂに接
するように、所定の間隔をおいて第２の水平ト゛レーン材
３４ｂを敷設する。また、可撓管３７を介して前記第１
の排水材３３ａと第２の排水材３３ｂとを接続する。Next, in the step i), ie, as shown in FIG. 14, a second layer
Is disposed, and a second horizontal train member 34b is laid at a predetermined interval so as to be in contact with the second drainage member 33b. Also, the first tube is connected via a flexible tube 37.
Drain material 33a and the second drain material 33b.
【００７３】この後、ｊ）、ｋ）の工程、つまり前記凹
部内（固化した土砂３５の層の上面）に再度土砂４２を
撒き出し、土砂４２からなる層の上面を気密シート４３
で覆い、真空ポンプ４０を作動させるのである。これに
より、真空ポンプ４０からの負圧が、真空タンク３２、
第１、第２の排水材３３ａ、３３ｂ、第１、第２の水平
ト゛レーン材３４ａ、３４ｂ、可撓管３７を介して土砂３
５、４２からなる層に伝わり、図１４中矢印に示すよう
に、土砂層中の水分と空気が、第１、第２の水平ドレー
ン材３４ａ、３４ｂへと吸い出され、第１、第２の排水
材３３ａ、真空タンク３、耐圧ホース４１を介して排水
され、土砂３５、４２からなる層が固化するようになっ
ている。勿論この場合も、固化した土砂３５の層の上面
への土砂４２の撒き出しにより、地盤Ａには、土砂３５
の荷重に加え、土砂４２の荷重が加わることになり、こ
の荷重の載加により、地盤Ａの圧密脱水も進行すること
になる。Thereafter, the steps j) and k), that is, the earth and sand 42 are again scattered into the recess (the upper surface of the layer of the solidified earth and sand 35), and the upper surface of the layer made of the earth and sand 42 is sealed with the airtight sheet 43.
Then, the vacuum pump 40 is operated. As a result, the negative pressure from the vacuum pump 40 is
The first and second drainage members 33a and 33b, the first and second horizontal train members 34a and 34b, and the sediment 3
The moisture and air in the sediment layer are sucked out into the first and second horizontal drain members 34a and 34b as shown by arrows in FIG. Is drained through the drainage material 33a, the vacuum tank 3, and the pressure-resistant hose 41, and the layer composed of the earth and sand 35, 42 is solidified. Of course, also in this case, the soil A is scattered on the ground A by spreading the soil 42 on the upper surface of the layer of the solidified soil 35.
In addition to the load, the load of the earth and sand 42 is added, and the consolidation and dewatering of the ground A also proceeds by the application of this load.
【００７４】次いで、図１５に示すように、上記ｉ）、
ｊ）、ｋ）の工程を繰り返すのである。これにより、地
盤Ａは、繰り返し載加される土砂による圧密載荷重によ
って圧密脱水が効果的に進行し、硬化地盤へと改良され
るようになる。同時に地盤Ａ上の土砂層も、土砂による
圧密載荷重と負圧力とによって圧密脱水が効果的に進行
し、盛土材などに再生利用ができるまでに固化処理がな
されるようになる。Next, as shown in FIG.
The steps j) and k) are repeated. Thereby, the consolidation dewatering of the ground A is effectively advanced by the consolidation load due to the repeatedly applied earth and sand, and the ground A is improved to the hardened ground. At the same time, the consolidation load and the negative pressure due to the consolidation of the soil and sand layer on the ground A are effectively dewatered by consolidation, and the solidification process is performed before the material can be recycled into the embankment material.
【００７５】また、図１５に示すように、固化した土砂
をそのまま盛土材として用い、軟弱地盤Ａ上に堤防を造
成することができる。As shown in FIG. 15, the embankment can be formed on the soft ground A using the solidified earth and sand as the embankment material as it is.
【００７６】尚、前記ｃ）〜ｆ）の工程を繰り返す毎
に、地盤Ａの凹部３０底面に設置した真空タンク３２
は、図１３〜図１５に示すように、地盤Ａと共に沈下す
ることになる。真空タンク３２の沈下に伴い、真空ポン
プ４０による負圧能力も低下していくことになる。とい
うのは真空ポンプ４０は本来負圧発生手段であるが、沈
下した深さ（高さ）分だけ、地盤間隙水を揚水しなけれ
ばならなくなり、その揚水に真空ポンプ４０の負圧力が
利用され、その結果として真空ポンプ４０による負圧能
力も低下することになるからである。このような不具合
の発生を解消するため、本例では、水中ポンプ（図示し
ない）を内蔵した真空タンク３２を設置している。これ
により真空タンク３２内の間隙水は、常時、水中ポンプ
の稼働によって排水されるので、真空ポンプ４０による
真空度ロスを軽減することができる。尚、水中ポンプが
故障したときに対処すべく、真空タンク内の底部に耐圧
ホースを設置して地上（外側）まで配管しておくとよ
い。また本例では、タンク内に水中ポンプを設置した真
空タンクを採用したが、地盤間隙水を排水するための排
水ポンプを備えるものならば何でも良く、例えばタンク
外部に排水ポンプを付設した真空タンク、あるいは地上
に設置した排水ポンプと連結させた真空タンクなども用
いることができる。Each time the steps c) to f) are repeated, the vacuum tank 32 installed on the bottom surface of the concave portion 30 of the ground A
Will sink together with the ground A, as shown in FIGS. As the vacuum tank 32 sinks, the negative pressure capability of the vacuum pump 40 also decreases. This is because the vacuum pump 40 is originally a negative pressure generating means, but it is necessary to pump the ground pore water by the depth (height) of the sink, and the negative pressure of the vacuum pump 40 is used for the pumping. As a result, the negative pressure capability of the vacuum pump 40 also decreases. In order to eliminate such a problem, in this example, a vacuum tank 32 having a built-in submersible pump (not shown) is installed. Thereby, the pore water in the vacuum tank 32 is constantly drained by the operation of the submersible pump, so that the loss of the degree of vacuum caused by the vacuum pump 40 can be reduced. In order to cope with a failure of the submersible pump, it is preferable to install a pressure-resistant hose at the bottom of the vacuum tank and pipe it to the ground (outside). In addition, in this example, a vacuum tank having a submersible pump installed in the tank was adopted, but any device having a drain pump for draining ground pore water may be used.For example, a vacuum tank having a drain pump attached outside the tank, Alternatively, a vacuum tank connected to a drain pump installed on the ground can be used.
【００７７】尚、各工程に使用される第１、第２の水平
ドレーン材、第１、第２の排水材、可撓管、及び気密シ
ートのいずれか又は全てを生分解性成形材料により構成
することもできる。生分解性成形材料とは土中又は水中
に存在する微生物や水分などにより容易に分解してしま
う材料をいう。この生分解性成形材料によって構成され
た第１、第２の水平ドレーン材、第１、第２の排水材、
可撓管、及び気密シートを用いて、上述の方法に従い改
良工法を施工した場合、第１、第２の水平ドレーン材、
第１、第２の排水材、可撓管、及び気密シートを構成す
る生分解性成形材料が、地盤、土砂内の土中又は水中に
存在する微生物や水分などにより容易に分解してしまう
ため、これらの部材を撤去する必要がなく、軟弱地盤の
改良に要する費用と手間とを大幅に削減することができ
る。It is to be noted that any or all of the first and second horizontal drain materials, first and second drainage materials, flexible pipes, and airtight sheets used in each step are made of a biodegradable molding material. You can also. The biodegradable molding material refers to a material which is easily decomposed by microorganisms or water existing in soil or water. A first and a second horizontal drain material, a first and a second drainage material constituted by the biodegradable molding material,
When a flexible pipe and an airtight sheet are used to perform an improved construction method according to the above-described method, the first and second horizontal drain members are provided.
Since the biodegradable molding materials constituting the first and second drainage materials, the flexible pipe, and the airtight sheet are easily decomposed by microorganisms and water present in the ground, in soil in soil or in water, or the like. It is not necessary to remove these members, and the cost and labor required for improving the soft ground can be significantly reduced.
【００７８】また生分解性成形材料としては、芋類、米
麦類、コーン類などの澱粉質、澱粉に酢酸ビニルなどの
ビニルモノマーを共重合させた澱粉質誘導体、パルプ、
セルロースなどの植物繊維又は植物粉末、天然ゴム、ア
ラビアゴムなどの植物性高分子、ガゼイン、ゼラチン、
グルテンなどの動物性タンパク質といった天然高分子を
主体とするものが好ましい。というのは、これら天然高
分子を主体とするものにあっては、施工後に地盤内で分
解しても環境に悪影響を与えることがないからである。Examples of the biodegradable molding material include starches such as potatoes, rice and wheat, corns, starchy derivatives obtained by copolymerizing starch with a vinyl monomer such as vinyl acetate, pulp, and the like.
Plant fibers or plant powders such as cellulose, natural rubber, vegetable polymers such as gum arabic, casein, gelatin,
Those mainly composed of natural polymers such as animal proteins such as gluten are preferred. This is because, in the case of these natural polymer-based materials, even if they are decomposed in the ground after construction, they do not adversely affect the environment.
【００７９】尚、請求項９〜１５記載の改良工法を、埋
立造成区域などの軟弱地盤に適用する場合、埋立造成時
には、埋立造成区域の周囲を浚渫することから、その際
に生じる浚渫泥を凹部内に撒き出す土砂とすればよい。
これにより、軟弱地盤の改良と浚渫泥の処理とが同時に
行えるようになる。また、河川や港湾などの浚渫工事の
際に生じた浚渫泥を、この改良工法を適用するときに、
凹部内に撒き出す土砂として用いることもできる。When the improved method according to claims 9 to 15 is applied to soft ground such as a landfill area, the surrounding area of the landfill area is dredged at the time of landfill. What is necessary is just to make the earth and sand scattered in a recessed part.
Thereby, improvement of soft ground and treatment of dredging mud can be performed simultaneously. Also, when applying this improved construction method, dredging mud generated during dredging work on rivers and ports,
It can also be used as earth and sand scattered in the recess.
【００８０】[0080]
【発明の効果】請求項１〜８記載の軟弱地盤の改良工法
にあっては、ａ）〜ｈ）の工程を有することから、土砂
層による圧密載荷重と負圧力とによって地盤及び土砂層
の圧密脱水が効果的に進行し、より効率的な軟弱地盤の
硬化地盤への改良がなされる。According to the method for improving soft ground described in claims 1 to 8, since the method includes the steps a) to h), the soil and the soil layer are compacted by the consolidation load of the soil layer and the negative pressure. The consolidation dewatering effectively proceeds, and a more efficient improvement of the soft ground to the hardened ground is performed.
【００８１】また、上記工法においてｅ）ｆ）ｇ）の工
程を繰り返すことで、土砂層による圧密載荷重と負圧力
とによる軟弱地盤及び土砂層の圧密脱水はさらに進行
し、より確かな硬化地盤への改良がなされるようにな
る。Further, by repeating the steps e), f) and g) in the above construction method, the consolidation dewatering of the soft ground and the sediment layer due to the consolidation load and the negative pressure by the sediment layer further progresses, and a more reliable hardened ground Will be improved.
【００８２】また、土砂層が浚渫泥によるものの場合に
は、上記圧密載荷重と負圧力とによる圧密脱水で、地盤
改良と同時に浚渫泥の処理も行うことができる。When the soil layer is made of dredged mud, the consolidation dewatering by the consolidation load and the negative pressure enables the dredged mud to be treated simultaneously with the ground improvement.
【００８３】また、前記各工程に使用される鉛直ト゛レー
ン材、通水材及び気密シートのいずれか又は全てに、生
分解性成形材料（特に好ましくは天然高分子）を用いた
ならば、これらの部材が地盤内で容易に分解してしまう
ので、これらの部材を撤去する必要がなく、軟弱地盤の
改良に要する費用と手間とを大幅に削減することができ
る。Further, if a biodegradable molding material (particularly preferably a natural polymer) is used for any or all of the vertical train material, the water-permeable material and the airtight sheet used in each of the above steps, Since the members are easily disassembled in the ground, there is no need to remove these members, and the cost and labor required for improving the soft ground can be significantly reduced.
【００８４】また、上記工法において、真空ポンプを間
欠的に作動させることもでき、この場合、地盤上面は、
負圧の状態と常圧の状態とが交互に造り出されることに
なる。負圧の状態から常圧の状態に変わるとき、その圧
力差によって地盤中に空気が一気に入り込むことにな
り、その衝撃力によって脱水により閉塞状態となってい
た地盤を構成する粒子間隔が広がり、地盤中の水及び空
気の排出経路が確保され、より効率的な水及び空気の排
出がなされるようになる。In the above method, the vacuum pump can be operated intermittently. In this case,
A state of negative pressure and a state of normal pressure are created alternately. When changing from a negative pressure state to a normal pressure state, the pressure difference causes air to enter the ground, and the impact force expands the space between particles that have been closed due to dehydration, and the ground A drain path for water and air inside is ensured, and water and air can be discharged more efficiently.
【００８５】また、真空ポンプを間欠的に作動させる場
合において、負圧の状態から常圧の状態へと変わるとき
に、空気を送り込むようにすることもできる。この場合
には、地盤に作用する衝撃力もより大きくなり、地盤、
特に鉛直ト゛レーン材周りの地盤を構成する粒子間隙はよ
り大きく広がり、水と空気はより通り易くなり、より効
果的な排水がなされるようになる。尚、地盤中の水及び
空気の排出経路を確保するため、鉛直ト゛レーン材を振動
させるという方法を採ることもできる。In the case where the vacuum pump is operated intermittently, air may be supplied when changing from a negative pressure state to a normal pressure state. In this case, the impact force acting on the ground becomes larger, and the ground,
In particular, the gaps between the particles constituting the ground around the vertical train material are larger, the water and the air are easier to pass through, and the drainage is more effective. Incidentally, a method of vibrating the vertical train material may be adopted in order to secure a discharge path for water and air in the ground.
【００８６】請求項９〜１５記載の軟弱地盤の改良工法
にあっては、ａ）〜ｆ）の工程を有することから、圧密
沈下が大きな場合でも、土砂層による圧密載荷重と負圧
力とによって地盤及び土砂層の圧密脱水が効果的に進行
し、効率的な軟弱地盤の硬化地盤への改良がなされる。In the method for improving soft ground according to the ninth to fifteenth aspects, since the method includes the steps a) to f), even if the consolidation settlement is large, the consolidation load by the earth and sand layer and the negative pressure can be applied. The consolidation and dewatering of the ground and the earth and sand layer effectively proceed, and an efficient soft ground is improved to a hardened ground.
【００８７】また、上記工法においてｄ）ｅ）ｆ）の工
程を繰り返すことで、より効果的でかつ確実な地盤の改
良がなされるようになる。Further, by repeating the steps d), e) and f) in the above construction method, more effective and reliable ground improvement can be achieved.
【００８８】また、土砂層が浚渫泥によるものの場合に
は、上記圧密載荷重と負圧力とによる圧密脱水で、地盤
改良と同時に浚渫泥の処理も行うことができる。When the soil layer is made of dredged mud, the consolidation dewatering by the above-mentioned consolidation load and negative pressure can simultaneously treat the ground improvement and the dredged mud treatment.
【図１】 地盤中に鉛直ト゛レーン材を打設した状態を示
す断面図。FIG. 1 is a cross-sectional view showing a state where a vertical train material is cast in the ground.
【図２】 鉛直ト゛レーン材上端部と接触するように平行
状に通水材を配置した状態を示す断面図。FIG. 2 is a cross-sectional view showing a state where a water-permeable material is arranged in parallel so as to be in contact with an upper end portion of a vertical train material.
【図３】 通水材を示す要部拡大断面図。FIG. 3 is an enlarged sectional view of a main part showing a water-permeable material.
【図４】 地盤上を前記鉛直ト゛レーン材上端部及び通水
材とともに気密シートで覆った状態を示す断面図。FIG. 4 is a cross-sectional view showing a state in which the ground is covered with an airtight sheet together with an upper end portion of the vertical train material and a water-permeable material.
【図５】 水と空気が吸い出された後の鉛直ト゛レーン材
周りの地盤を示す模式図。FIG. 5 is a schematic view showing the ground around a vertical train material after water and air are sucked out.
【図６】 負圧状態から常圧の状態へ戻すことにより、
鉛直ト゛レーン材周りの地盤を構成する粒子間隙を広げた
状態を示す模式図。FIG. 6 By returning from a negative pressure state to a normal pressure state,
The schematic diagram which shows the state which expanded the particle | grain gap which comprises the ground around a vertical train material.
【図７】 本発明の改良工法により圧密沈下した地盤の
凹部を示す断面図。FIG. 7 is a cross-sectional view showing a concave portion of the ground which has been compacted and settled by the improved method of the present invention.
【図８】 圧密沈下した地盤の気密シート上に土砂を撒
き出した状態を示す断面図。FIG. 8 is a cross-sectional view showing a state in which earth and sand are scattered on an airtight sheet of the consolidated ground.
【図９】 土砂層中に鉛直ト゛レーン材を打設すると共に
土砂層上面を気密シートで覆った状態を示す断面図。FIG. 9 is a cross-sectional view showing a state in which a vertical train material is cast in the earth and sand layer and the upper surface of the earth and sand layer is covered with an airtight sheet.
【図１０】 圧密沈下した地盤の凹部を示す断面図。FIG. 10 is a cross-sectional view showing a concavity in the concavity of the ground.
【図１１】 圧密沈下した凹部内にさらに土砂を撒き出
した状態を示す断面図。FIG. 11 is a cross-sectional view showing a state in which earth and sand are further scattered into the concavity-concaved depression.
【図１２】 圧密沈下した凹部内に第１の排水材、真空
タンクを設置する共に、第１の水平ト゛レーン材を敷設し
た状態を示す平面図。FIG. 12 is a plan view showing a state where a first drainage material and a vacuum tank are installed in a concavity-concaved recess, and a first horizontal train material is laid.
【図１３】 同じく断面図。FIG. 13 is a sectional view of the same.
【図１４】 固化後の土砂層の上面に第２の排水材を設
置する共に、第２の水平ト゛レーン材を敷設した状態を示
す平面図。FIG. 14 is a plan view showing a state in which a second drainage material is installed on the upper surface of the soil layer after solidification and a second horizontal train material is laid.
【図１５】 固化した土砂を盛土材として、軟弱地盤上
に堤防を造成した状態を示す断面図。FIG. 15 is a cross-sectional view showing a state in which a bank has been formed on soft ground using solidified earth and sand as an embankment material.
【図１６】 従来の軟弱軟弱地盤の改良施工装置を示す
断面図。FIG. 16 is a cross-sectional view showing a conventional apparatus for improving soft and soft ground.
１１、２４・・・鉛直ト゛レーン材 １３・・・通水材 １６、４０・・・真空ポンプ １７・・・真空タンク １８、２５、３６、４３・・・気密シート ２１・・・砂層 ２２、２６、３５、４２・・・土砂 ３０・・・凹部 ３２・・・真空タンク（水中ポンプ内蔵） ３３ａ、３３ｂ・・・排水材 ３４ａ、３４ｂ・・・水平ト゛レーン材 11, 24: Vertical train material 13: Water-permeable material 16, 40: Vacuum pump 17: Vacuum tank 18, 25, 36, 43: Airtight sheet 21: Sand layer 22, 26 , 35, 42 ... soil 30 ... recess 32 ... vacuum tank (built-in submersible pump) 33a, 33b ... drainage material 34a, 34b ... horizontal train material
Claims (14)
特徴とする軟弱地盤の改良工法。 ａ） 鉛直ト゛レーン材を上端部を残して地盤中に所定の
間隔をおいて打設することにより、地盤中に鉛直排水壁
を造成する工程、 ｂ） 前記鉛直ト゛レーン材上端部と接触するように水平
状に真空ポンプに連結した通水材を配置する工程、 ｃ） 前記鉛直ト゛レーン材上端部及び通水材を砂層で覆
う工程、 ｄ） 前記地盤上を前記鉛直ト゛レーン材上端部、通水材
及び砂層とともに気密シートで覆う工程、 ｅ） 前記真空ポンプを作動させて地盤上面に負圧の状
態を造り出す工程、 ｆ） 前記地盤の圧密沈下後の凹部内に土砂を撒き出す
工程、 ｇ） 前記土砂層に前記気密シートを貫通して前記砂層
に至る深さまで鉛直ト゛レーン材を打設する工程、 ｈ） 前記真空ポンプを作動させて前記地盤上面に負圧
の状態を造り出し、前記土砂層中に打設した鉛直ト゛レー
ン材を介して土砂層中の水及び空気を排出させる工程。1. A method for improving soft ground, comprising the following steps a) to h). a) forming a vertical drainage wall in the ground by placing a vertical train material in the ground at a predetermined interval while leaving the upper end thereof; b) contacting the vertical train material with the upper end of the vertical train material. Arranging the water-permeable material connected to the vacuum pump horizontally; c) covering the upper end of the vertical train material and the water-permeable material with a sand layer; d) upper end of the vertical train material on the ground, the water-permeable material. E) a step of operating the vacuum pump to create a negative pressure state on the ground surface, f) a step of dispersing earth and sand in a concave portion of the ground after consolidation settlement, and g) the above. A step of driving a vertical train material through the airtight sheet to a depth reaching the sand layer in the soil layer, h) operating the vacuum pump to create a negative pressure state on the ground surface, and Casting Step of discharging the water and air of sediment layer was via a vertical Doreen material.
ことを特徴とする請求項１記載の軟弱地盤の改良工法。2. The method for improving soft ground according to claim 1, wherein the steps e), f) and g) are repeated.
泥であることを特徴とする請求項１または２記載の軟弱
地盤の改良工法。3. The method for improving soft ground according to claim 1, wherein the earth and sand put on the airtight sheet is dredge mud.
材、通水材及び気密シートのいずれか又は全てが、生分
解性成形材料よりなることを特徴とする請求項１〜３記
載の軟弱地盤の改良工法。4. The soft ground according to claim 1, wherein at least one of the vertical train material, the water-permeable material, and the airtight sheet used in each of the steps is made of a biodegradable molding material. Improved construction method.
することを特徴とする請求項４記載の軟弱地盤の改良工
法。5. The method for improving soft ground according to claim 4, wherein the biodegradable molding material is mainly composed of a natural polymer.
で、地盤上面に常圧及び負圧の状態を交互に造り出す工
程をさらに含むことを特徴とする請求項１〜５のいずれ
かに記載の軟弱地盤の改良工法。6. The method according to claim 1, further comprising the step of intermittently operating a vacuum pump to alternately create a normal pressure state and a negative pressure state on the ground surface. Improvement method for soft ground.
と移行するときに、地盤上面に空気を送り込むことを特
徴とする請求項１〜６のいずれかに記載の軟弱地盤の改
良工法。7. The soft ground improvement according to claim 1, wherein air is blown into the ground upper surface when the ground upper surface shifts from a negative pressure state to a normal pressure state. Construction method.
したことを特徴とする請求項１〜７のいずれかに記載の
軟弱地盤の改良工法。8. The method for improving soft ground according to claim 1, wherein the vertical train is vibrated.
特徴とする軟弱地盤の改良工法。 ａ） 圧密沈下後の地盤の凹部底面に、真空ポンプと連
結し、排水ポンプを備えている真空タンクと、同真空タ
ンクと接続した第１の排水材とを設置すると共に、この
第１の排水材と接するように、所定の間隔をおいて第１
の水平ト゛レーン材を敷設する工程、 ｂ） 前記地盤の凹部内に土砂を撒き出す工程、 ｃ） 前記真空ポンプを作動させて、真空タンク、第１
の排水材、第１の水平ト゛レーン材を介して土砂層に含ま
れる水分及び空気を除去し、土砂層を固化させる工程、 ｄ） 前記固化した土砂上面に、第２の排水材を設置
し、この第２の排水材に接するように、所定の間隔をお
いて第２の水平ト゛レーン材を敷設すると共に、前記第２
の排水材と前記第１の排水材とを可撓管を介して接続す
る工程、 ｅ） 前記凹部内に再度土砂を撒き出す工程、 ｆ） 前記真空ポンプを作動させて、真空タンク、第
１、第２の排水材、第１、第２の水平ト゛レーン材、可撓
管を介して土砂層に含まれる水分及び空気を除去し、土
砂層を固化させる工程。9. A method for improving soft ground, comprising the following steps a) to f). a) A vacuum tank connected to a vacuum pump and provided with a drainage pump and a first drainage material connected to the vacuum tank are installed on the bottom of the concave portion of the ground after consolidation settlement, and the first drainage is connected to the vacuum pump. At a predetermined interval, the first
Laying the horizontal train material of the above, b) dispersing the earth and sand in the concave portion of the ground, c) operating the vacuum pump to form the vacuum tank,
Removing the water and air contained in the sediment layer through the first drainage material and the first horizontal train material to solidify the sediment layer; d) installing a second drainage material on the solidified soil and sand upper surface; A second horizontal train member is laid at a predetermined interval so as to be in contact with the second drainage member, and
Connecting the drainage material and the first drainage material through a flexible pipe, e) re-spreading the earth and sand into the concave portion, f) operating the vacuum pump to form a vacuum tank, Removing the moisture and air contained in the sediment layer through the second drainage material, the first and second horizontal train materials, and the flexible pipe, and solidifying the sediment layer.
下させて地盤に凹部を造成する工法が、以下のア）〜
オ）の工程からなることを特徴とする請求項９記載の軟
弱地盤の改良工法。 ア） 鉛直ト゛レーン材を上端部を残して地盤中に所定の
間隔をおいて打設することにより、地盤中に鉛直排水壁
を造成する工程、 イ） 前記鉛直ト゛レーン材上端部と接触するように水平
状に真空ポンプに連結した通水材を配置する工程、 ウ） 前記鉛直ト゛レーン材上端部及び通水材を砂層で覆
う工程、 エ） 前記地盤上を前記鉛直ト゛レーン材上端部、通水材
及び砂層とともに気密シートで覆う工程、 オ） 前記真空ポンプを作動させて地盤上面に負圧の状
態を造り出す工程。10. A method of forming a concave portion in the ground by consolidating the ground in the step of a) to form a recess in the ground is as follows:
10. The method for improving soft ground according to claim 9, comprising the step of e). A) a step of forming a vertical drainage wall in the ground by placing a vertical train material in the ground at a predetermined interval while leaving the upper end thereof, a) making contact with the upper end of the vertical train material. Arranging the water-permeable material connected to the vacuum pump horizontally; c) covering the upper end of the vertical train material and the water-permeable material with a sand layer; d) upper end of the vertical train material on the ground, the water-permeable material. And a step of covering with an airtight sheet together with the sand layer. E) a step of operating the vacuum pump to create a negative pressure state on the ground surface.
すことを特徴とする請求項９または１０記載の軟弱地盤
の改良工法。11. The method for improving soft ground according to claim 9, wherein the steps d), e) and f) are repeated.
砂が浚渫泥であることを特徴とする請求項９〜１１記載
の軟弱地盤の改良工法。12. The method for improving soft ground according to claim 9, wherein the earth and sand scattered in the recess after the consolidation settlement is dredge mud.
水平ト゛レーン材、第１、第２の排水材及び可撓管のいず
れか又は全てが、生分解性成形材料よりなることを特徴
とする請求項９〜１２記載の軟弱地盤の改良工法。13. The method according to claim 1, wherein any or all of the first and second horizontal train members, the first and second drainage members, and the flexible pipe used in each of the steps are made of a biodegradable molding material. The method for improving soft ground according to any one of claims 9 to 12, wherein:
とすることを特徴とする請求項１３記載の軟弱地盤の改
良工法。14. The method for improving soft ground according to claim 13, wherein the biodegradable molding material is mainly composed of a natural polymer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23583098A JP4058550B2 (en) | 1997-08-22 | 1998-08-21 | Improvement method for soft ground |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22623597 | 1997-08-22 | ||
| JP9-226235 | 1997-08-22 | ||
| JP23583098A JP4058550B2 (en) | 1997-08-22 | 1998-08-21 | Improvement method for soft ground |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11131465A true JPH11131465A (en) | 1999-05-18 |
| JP4058550B2 JP4058550B2 (en) | 2008-03-12 |
Family
ID=26527072
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23583098A Expired - Lifetime JP4058550B2 (en) | 1997-08-22 | 1998-08-21 | Improvement method for soft ground |
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| Country | Link |
|---|---|
| JP (1) | JP4058550B2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6655873B2 (en) | 2000-10-04 | 2003-12-02 | Boskalis Westminster, Inc. | Method and apparatus for consolidating earth strata |
| KR100463314B1 (en) * | 2002-07-12 | 2004-12-29 | 김윤상 | Soil Improvement Method of Soft Clay Using Water as Surcharge Load in Large Land |
| KR100870465B1 (en) * | 2007-02-12 | 2008-11-25 | 장지건 | Preloading method by controlling of buoyancy |
| JP2011132660A (en) * | 2009-12-22 | 2011-07-07 | Railway Technical Research Institute | Banking with airtight structure |
| CN105239555A (en) * | 2015-09-28 | 2016-01-13 | 华中科技大学 | Method for treating soft soil foundation through combination of bagged grouting gravel pile and vacuum preloading |
| WO2019187169A1 (en) * | 2018-03-27 | 2019-10-03 | 正佳 近藤 | Vacuum consolidation dredging method, tower air-tight loading caisson, and dedicated work ship |
| CN111455974A (en) * | 2020-03-04 | 2020-07-28 | 温州大学 | Vacuum preloading flocculation drainage method for transverse drainage plate combined geotextile |
| CN114000495A (en) * | 2021-11-22 | 2022-02-01 | 中交第一航务工程局有限公司 | Underwater vacuum preloading process |
| CN114457784A (en) * | 2022-03-18 | 2022-05-10 | 汕尾市广投建设工程有限公司 | Prepressing structure of coastal sludge geological soft soil foundation and construction process thereof |
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1998
- 1998-08-21 JP JP23583098A patent/JP4058550B2/en not_active Expired - Lifetime
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6655873B2 (en) | 2000-10-04 | 2003-12-02 | Boskalis Westminster, Inc. | Method and apparatus for consolidating earth strata |
| US6991406B2 (en) | 2000-10-04 | 2006-01-31 | Dirk Albertus Bodegom | Method and apparatus for consolidating earth strata |
| KR100463314B1 (en) * | 2002-07-12 | 2004-12-29 | 김윤상 | Soil Improvement Method of Soft Clay Using Water as Surcharge Load in Large Land |
| KR100870465B1 (en) * | 2007-02-12 | 2008-11-25 | 장지건 | Preloading method by controlling of buoyancy |
| JP2011132660A (en) * | 2009-12-22 | 2011-07-07 | Railway Technical Research Institute | Banking with airtight structure |
| CN105239555A (en) * | 2015-09-28 | 2016-01-13 | 华中科技大学 | Method for treating soft soil foundation through combination of bagged grouting gravel pile and vacuum preloading |
| WO2019187169A1 (en) * | 2018-03-27 | 2019-10-03 | 正佳 近藤 | Vacuum consolidation dredging method, tower air-tight loading caisson, and dedicated work ship |
| WO2019187174A1 (en) * | 2018-03-27 | 2019-10-03 | 正佳 近藤 | Vacuum consolidation dredging method, tower air-tight loading caisson, and dedicated work ship |
| CN111455974A (en) * | 2020-03-04 | 2020-07-28 | 温州大学 | Vacuum preloading flocculation drainage method for transverse drainage plate combined geotextile |
| CN114000495A (en) * | 2021-11-22 | 2022-02-01 | 中交第一航务工程局有限公司 | Underwater vacuum preloading process |
| CN114457784A (en) * | 2022-03-18 | 2022-05-10 | 汕尾市广投建设工程有限公司 | Prepressing structure of coastal sludge geological soft soil foundation and construction process thereof |
| CN114922131A (en) * | 2022-05-19 | 2022-08-19 | 天津大学 | Settlement installation method for large-size steel cylinder dyke dam retaining wall structure in ocean water body |
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