JPS644004B2 - - Google Patents
Info
- Publication number
- JPS644004B2 JPS644004B2 JP2712281A JP2712281A JPS644004B2 JP S644004 B2 JPS644004 B2 JP S644004B2 JP 2712281 A JP2712281 A JP 2712281A JP 2712281 A JP2712281 A JP 2712281A JP S644004 B2 JPS644004 B2 JP S644004B2
- Authority
- JP
- Japan
- Prior art keywords
- sand
- sand drain
- drain
- soft ground
- water
- 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
Links
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)
- Life Sciences & Earth Sciences (AREA)
- Structural Engineering (AREA)
- Agronomy & Crop Science (AREA)
- Environmental & Geological Engineering (AREA)
- Soil Sciences (AREA)
- General Life Sciences & Earth Sciences (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)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明はシルト質土、粘土質土層からなる軟弱
地盤を透水性の筒状袋体で包んだサンドドレーン
工法によつて地盤改良する技術に関する。[Detailed Description of the Invention] (Industrial Application Field) The present invention is a technology for improving the soft ground consisting of silty soil and clay soil by using the sand drain method, which is wrapped in a water-permeable cylindrical bag. Regarding.
（従来技術）
従来粘性土からなる軟弱地盤を砂材より成るサ
ンドドレーンによつて圧密脱水して地盤改良を行
つているが、サンドドレーン打設工事中にサンド
ドレーンが軟弱地盤中で上下に切断されて不連続
になることを防止する為に高分子材料等からなる
透水性の良い粗目のシート材で筒状袋体を作り、
この筒状袋体内に砂を充填してサンドドレーンを
造成している。(Prior technology) Conventionally, soft ground made of cohesive soil is improved by consolidation dewatering using a sand drain made of sand material, but during sand drain construction work, the sand drain cuts vertically in the soft ground. In order to prevent the bag from becoming discontinuous due to water leakage, a cylindrical bag is made from a coarse sheet material with good water permeability made of polymeric material, etc.
This cylindrical bag is filled with sand to create a sand drain.
しかし軟弱地盤中に約1m前後のピツチで上記
方法でサンドドレーンを造成し、その後サンドド
レーン造成地域上に土砂による圧密載荷重を上載
して軟弱地盤の圧密脱水を行う際、サンドドレー
ンを被覆している前記筒状袋体が非常に丈夫な
為、この筒状袋体がサンドドレーンの変形を拘束
する結果、ドレーン材である砂は密に締め固めら
れ、筒状袋体を含むサンドドレーンが一種の抗状
体のようになつて、前記圧密載荷重の殆どをサン
ドドレーンが支持してしまい、又サンドドレーン
が自由に曲がらない為サンドドレーンに対してネ
ガテイブフリクシヨン（サンドドレーンによつて
軟弱地盤の沈下が阻止される現象）が生じ、上記
と相俟つて載荷重は深部に行くに従つて軽減され
る事となり、従つて肝心の軟弱土層への載荷効果
が薄れ、圧密脱水に必要な軟弱土層中の過剰間隙
水圧も十分に発生しないため地盤改良効果にも悪
影響を及ぼす欠点があつた。 However, when a sand drain is created in soft ground using the above method at a pitch of about 1 m, and then a consolidation load of earth and sand is placed on top of the sand drain creation area to perform consolidation dewatering of the soft ground, the sand drain is covered. Since the cylindrical bag is very strong, this cylindrical bag restrains the deformation of the sand drain, and as a result, the sand that is the drain material is tightly compacted, and the sand drain including the cylindrical bag is The sand drain becomes like a kind of resistance body and supports most of the consolidation load, and since the sand drain cannot bend freely, there is a negative friction against the sand drain (soft and weak due to the sand drain). Coupled with the above, the applied load is reduced as it goes deeper, which weakens the loading effect on the important soft soil layer, which is necessary for consolidation and dewatering. The problem was that excess pore water pressure in the soft soil layer was not sufficiently generated, which had a negative impact on the ground improvement effect.
（発明の目的）
本発明の目的は上記のような欠点を除くように
したサンドドレーンによる軟弱地盤改良工法を得
るにある。(Object of the Invention) The object of the present invention is to obtain a method for improving soft ground using a sand drain, which eliminates the above-mentioned drawbacks.
（発明の構成）
本発明のサンドドレーンによる軟弱地盤改良工
法は透水性シートを長い筒状に丸めその合わせ目
を水によつて溶解する性質の接合剤によつて接合
して形成した筒状袋内に砂を充填して成るサンド
ドレーンを軟弱地盤中に造成する工程と、前記サ
ンドドレーンの造成地域上に土砂を載荷する工程
とより成り、前記透水性シートを接合している接
着剤が地盤中の水分によつて溶解されて前記筒状
袋体が開き軟弱地盤の上下方向の収縮に応じて前
記サンドドレーンが変形できるようになることを
特徴とする。(Structure of the Invention) The soft ground improvement method using a sand drain of the present invention is a cylindrical bag formed by rolling a water-permeable sheet into a long cylindrical shape and joining the seams with a bonding agent that dissolves in water. The process consists of a step of creating a sand drain in soft ground by filling it with sand, and a step of loading earth and sand onto the area where the sand drain is created, so that the adhesive bonding the water permeable sheet is firmly attached to the ground. The sand drain is characterized in that the cylindrical bag is opened by being dissolved by the moisture contained therein, and the sand drain becomes deformable in accordance with the contraction of the soft ground in the vertical direction.
（発明の実施例） 以下図面によつて本発明の実施例を説明する。(Example of the invention) Embodiments of the present invention will be described below with reference to the drawings.
第１図において１は改良すべき軟弱層、２はこ
の軟弱層１内に互いに所定の間隔をおいて造成し
たサンドドレーン、３はこのサンドドレーンを囲
む透水性の良いシート材から成る筒状袋体、４は
載荷重としての土砂、５はサンドマツトを示し、
本発明においては第２図に示すように筒状袋体３
として１枚のシートを筒状に丸め、その合わせ目
３′をセルロース系、尿素系等水溶性の接着剤を
用いて接着して形成したサンドドレーンを軟弱地
盤中に造成し、前記サンドドレーンの造成後にこ
の造成地域上に土砂を載荷して圧密脱水を行わせ
る。 In Fig. 1, 1 is a soft layer to be improved, 2 is a sand drain formed within this soft layer 1 at a predetermined distance from each other, and 3 is a cylindrical bag made of a sheet material with good water permeability surrounding this sand drain. 4 indicates earth and sand as a load, 5 indicates sand mats,
In the present invention, as shown in FIG.
A sand drain is created in the soft ground by rolling one sheet into a cylindrical shape and gluing the seam 3' using a water-soluble adhesive such as cellulose or urea. After the land is created, soil is loaded onto the created area to perform consolidation and dewatering.
（発明の効果）
上記のような筒状袋体を使用すればその施工後
数日でシートを接合している接着剤が溶解し、筒
状袋体が開き、次いで圧密沈下に伴う地盤の収縮
によつて筒状袋体が自由に変形するようになる。(Effect of the invention) If the above-mentioned cylindrical bag is used, the adhesive that joins the sheets will dissolve in a few days after construction, the cylindrical bag will open, and the ground will shrink due to consolidation settlement. This allows the cylindrical bag to deform freely.
即ち軟弱地盤中におけるサンドドレーンの筒状
袋体による拘束が開放されるので、サンドドレー
ンは地盤の収縮に対して無抵抗となり、その結果
圧密載荷重が軟弱地盤に有効に伝達されて良好な
地盤改良を行うことが出来る。 In other words, the restraint of the sand drain in the soft ground by the cylindrical bag body is released, so the sand drain has no resistance to the contraction of the ground, and as a result, the consolidation load is effectively transmitted to the soft ground, resulting in a good ground condition. Improvements can be made.
第１図はサンドドレーン工法の説明図、第２図
は本発明工法に用いる筒状袋体の説明図である。
１……軟弱層、２……サンドドレーン、３……
筒状袋体、４……土砂、５……サンドマツト。
FIG. 1 is an explanatory diagram of the sand drain construction method, and FIG. 2 is an explanatory diagram of a cylindrical bag used in the construction method of the present invention. 1...Soft layer, 2...Sand drain, 3...
Tubular bag body, 4... earth and sand, 5... sand mats.
Claims (1)
を水によつて溶解する性質の接合剤によつて接合
して形成した筒状袋内に砂を充填して成るサンド
ドレーンを軟弱地盤中に造成する工程と、前記サ
ンドドレーンの造成地域上に土砂を載荷する工程
とより成り、前記透水性シートを接合している接
着剤が地盤中の水分によつて溶解されて前記筒状
袋体が開き軟弱地盤の上下方向の収縮に応じて前
記サンドドレーンが変形できるようになることを
特徴とするサンドドレーンによる軟弱地盤改良工
法。1. A sand drain made by filling sand into a cylindrical bag formed by rolling a water-permeable sheet into a long cylindrical shape and joining the seams with a bonding agent that dissolves in water is inserted into soft ground. and a step of loading earth and sand onto the area where the sand drain is created, and the adhesive bonding the water-permeable sheet is dissolved by moisture in the ground and the cylindrical bag body is formed. A method for improving soft ground using a sand drain, characterized in that the sand drain can be deformed in accordance with vertical contraction of the open soft ground.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2712281A JPS57143010A (en) | 1981-02-27 | 1981-02-27 | Method for improving soft ground by sand drain |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2712281A JPS57143010A (en) | 1981-02-27 | 1981-02-27 | Method for improving soft ground by sand drain |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25508285A Division JPS61113921A (en) | 1985-11-15 | 1985-11-15 | Method of improving soft ground by means of sand drain |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57143010A JPS57143010A (en) | 1982-09-04 |
| JPS644004B2 true JPS644004B2 (en) | 1989-01-24 |
Family
ID=12212248
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2712281A Granted JPS57143010A (en) | 1981-02-27 | 1981-02-27 | Method for improving soft ground by sand drain |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57143010A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100431448B1 (en) * | 1999-12-29 | 2004-05-12 | 주식회사 포스코 | Device for leading muffle plug of bright annealing furnace |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2518494Y2 (en) * | 1990-07-13 | 1996-11-27 | 新晃通商株式会社 | Structure of bag for sand pile construction |
| CN103866754B (en) * | 2012-12-12 | 2016-06-01 | 中国二十冶集团有限公司 | It is applied to the combined vacuum and surcharge preloading constructional method of Soft Ground |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5231509A (en) * | 1975-08-25 | 1977-03-10 | Sekisui Chemical Co Ltd | Method of forming sand pile |
-
1981
- 1981-02-27 JP JP2712281A patent/JPS57143010A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100431448B1 (en) * | 1999-12-29 | 2004-05-12 | 주식회사 포스코 | Device for leading muffle plug of bright annealing furnace |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57143010A (en) | 1982-09-04 |
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