JPH0826536B2 - Consolidation promotion method for clay ground - Google Patents
Consolidation promotion method for clay groundInfo
- Publication number
- JPH0826536B2 JPH0826536B2 JP2080916A JP8091690A JPH0826536B2 JP H0826536 B2 JPH0826536 B2 JP H0826536B2 JP 2080916 A JP2080916 A JP 2080916A JP 8091690 A JP8091690 A JP 8091690A JP H0826536 B2 JPH0826536 B2 JP H0826536B2
- Authority
- JP
- Japan
- Prior art keywords
- cohesive
- drainage
- consolidation
- drainage channel
- groove
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000007596 consolidation process Methods 0.000 title claims description 21
- 238000000034 method Methods 0.000 title claims description 18
- 239000004927 clay Substances 0.000 title 1
- 239000003673 groundwater Substances 0.000 claims description 28
- 239000002689 soil Substances 0.000 claims description 27
- 239000000463 material Substances 0.000 claims description 20
- 230000001737 promoting effect Effects 0.000 claims description 9
- 230000000149 penetrating effect Effects 0.000 claims 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- 238000010276 construction Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 10
- 230000002411 adverse Effects 0.000 description 6
- 238000009412 basement excavation Methods 0.000 description 5
- 230000000903 blocking effect Effects 0.000 description 5
- 239000008239 natural water Substances 0.000 description 5
- 238000005056 compaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- 239000004576 sand Substances 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000012237 artificial material Substances 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000005445 natural material Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 239000013049 sediment Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
Landscapes
- 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） 本発明は粘性土地盤、特に正規圧密状態又は圧密未了
の状態にある沖積粘性土層の改良に関するものであり、
更に詳しくは、このような粘性土地盤においては一般的
に地下水が高いことを利用して載荷盛土をせずに、地盤
内の地下水位を低下させることにより、沖積粘性土層を
圧密して地盤改良を図る工法の改良に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to improvement of cohesive soil, especially alluvial cohesive soil layer in a normally consolidated state or an unconsolidated state,
More specifically, in such cohesive soils, the groundwater level is generally high to reduce the groundwater level in the ground without loading embankment to consolidate the alluvial cohesive soil layer. The present invention relates to improvement of a construction method for improvement.
（従来の技術） 近年、臨海地域いわゆるウォータフロントと呼ばれる
地域での開発が盛んに行われている。(Prior Art) In recent years, development has been actively carried out in waterfront areas, so-called waterfront areas.
このような地域の沖積粘性土層地盤は、圧密未了であ
ったり、正規圧密状態であっても軟弱な粘性土層を主体
として構成されることが多く、構造物の基礎地盤や宅地
として利用するためには何らかの地盤改良を必要とする
場合が多い。The alluvial cohesive soil ground in such areas is often composed mainly of a soft cohesive soil layer that has not been consolidated or is in a normally consolidated state, and is used as the foundation ground of a structure or residential land. In order to do so, it is often necessary to improve the ground.
従来、このような軟弱な粘性土地盤の圧密対策として
は種々の工法が提案され、実施されているが、比較的経
済的でかつ確実に改良効果が得られる方法として、載荷
盛土等による予圧密工法が知られている。Conventionally, various construction methods have been proposed and implemented as measures against consolidation of such soft cohesive soil, but as a method that is relatively economical and that can surely obtain the improvement effect, preconsolidation by loading embankment etc. The construction method is known.
この工法は構造物荷重に対応する圧密荷重を載荷盛土
によって、予め軟弱な粘性土地盤に負荷して、構造物基
礎として十分な耐力を付与しようとするものである。In this construction method, a compaction load corresponding to the structure load is preliminarily applied to the soft cohesive ground by the embankment to give sufficient proof stress as the structure foundation.
しかしながら、上記の載荷盛土工法においては、盛土
材の運搬及び盛土作業に際して多大な時間と費用を要
し、工事敷地周辺に土砂飛散等の環境問題が発生すると
いう問題があった。However, the above-mentioned loading embankment method has a problem in that it takes a lot of time and money for transportation of the embankment material and the embankment work, and environmental problems such as scattering of sediment occur around the construction site.
そこで第６図に示すように地下水位Ｗ（自然水位）を
低下させて粘性土地盤ｎ内の間隙水圧を減少させること
により、載荷盛土を必要とせずに、粘性土層n1を圧密改
良する地下水位低下工法が提案されている（土質工学会
「軟弱地盤対策工法」−調査・設計から施工まで−、現
場技術者のための土と基礎シリーズ16、P61〜P63参
照）。Therefore, as shown in FIG. 6, the groundwater level W (natural water level) is lowered to reduce the pore water pressure in the cohesive soil bed n, thereby improving the consolidation of the cohesive soil layer n 1 without the need for loading embankment. A groundwater level lowering method has been proposed (see Geotechnical Society "Soft ground countermeasure method" -from survey / design to construction-, Soil and Foundation Series 16 for field engineers, P61-P63).
（発明が解決しようとする課題） しかしながら、上記のような地下水位低下工法には、
以下のような問題がある。(Problems to be Solved by the Invention) However, in the above groundwater level lowering method,
There are the following problems.
（１）地下水位の低下が広い範囲にわたって影響して周
辺地盤に対しても圧密沈下が生じるので、この対策とし
て工事敷地の周囲に遮水壁を下部透水層のかなり深い位
置まで構築する必要がある。(1) Since the lowering of the groundwater level affects a wide area and consolidation settlement also occurs in the surrounding ground, it is necessary to construct an impermeable wall around the construction site to a deep position of the lower permeable layer as a countermeasure. is there.
（２）圧密層厚が大きい場合、改良効果を得るのに長期
間を要する。(2) When the consolidation layer thickness is large, it takes a long time to obtain the improvement effect.
（３）従来の地下水位低下工法では下部透水層まで揚水
井を掘削、構築して揚水する必要がある。(3) In the conventional groundwater level lowering method, it is necessary to excavate and construct a pumping well up to the lower permeable layer to pump water.
本発明は、上記のような（１）、（２）、（３）の問
題に鑑みてなされたものであり、その目的は、工事敷地
の周辺へ及ぼす悪影響をできるだけ少なくすると共に、
粘性土層の圧密を短期間でかつ経済的に促進させる工法
を提供することにある。The present invention has been made in view of the problems (1), (2), and (3) described above, and an object thereof is to minimize adverse effects on the periphery of a construction site,
It is to provide a method of promoting the consolidation of the cohesive soil layer in a short period of time and economically.
（課題を達成するための手段） 以上の課題を解決するための本発明の手段たる構成
は、粘性土地盤に粘性土層を貫通して下部透水層に到達
し、かつ平面的に連続した格子状の排水溝を形成し、該
排水溝からの強制排水によって地下水位を低下させて前
記粘性土層の圧密促進を図る工法であって、前記排水溝
における最も外側の排水溝の全長にわたって遮水材を設
置したことを特徴とし、 また、粘性土地盤に粘性土層を貫通して下部透水層に
到達し、かつ平面的に連続した格子状の排水溝を形成
し、該排水溝からの強制排水によって地下水位を低下さ
せて前記粘性土層の圧密促進を図る工法であって、前記
排水溝を格子状の薄型溝と、該薄型溝の交差部及び中途
部に形成された円形孔とから形成し、この排水溝におけ
る最も外側の排水溝の全長にわたって遮水材を設置した
ことを特徴とし、 また、前記遮水材を設置した最も外側の排水溝を、そ
の他の排水溝よりも深く掘削形成することを特徴とし、 また、前記格子状の排水溝における最も外側の排水溝
で囲まれた粘性土地盤の外側に復水井を掘削し、該復水
井に前記粘性土地盤内から揚水された地下水を還流する
ことを特徴とする構成にすることである。(Means for Achieving the Object) The structure which is the means of the present invention for solving the above-mentioned problems is a grid that penetrates a cohesive soil layer to reach a lower permeable layer in a cohesive ground, and is continuous in a plane. A drainage ditch is formed, and the groundwater level is lowered by forced drainage from the drainage ditch to promote consolidation of the cohesive soil layer. It is characterized by the installation of the material, and it also penetrates the cohesive soil layer to reach the lower permeable layer in the cohesive ground, and forms a grid-like drainage groove that is continuous in the plane and forced from the drainage groove. A method of lowering the groundwater level by drainage to promote consolidation of the cohesive soil layer, wherein the drainage groove is composed of lattice-shaped thin grooves, and circular holes formed at intersections and midway portions of the thin grooves. Form all of the outermost drains in this drain Further, a water blocking material is installed over the drainage groove, and the outermost drainage groove where the water blocking material is installed is formed deeper than the other drainage grooves. By constructing a condensate well outside the viscous ground bed surrounded by the outermost drainage groove in the groove, and recirculating the condensate well with groundwater pumped from within the viscous ground bed is there.
（作用） 上記構成によれば、粘性土地盤の地下水を排水溝から
強制的に排水して地下水位を低下させることにより、載
荷盛土を用いずに水位低下量に対応する圧密現象を生じ
させるとともに、格子状の排水溝がドレーン機能を発揮
するため圧密を促進させることができる。(Operation) According to the above configuration, by forcibly draining the groundwater of the cohesive ground from the drainage channel to lower the groundwater level, a compaction phenomenon corresponding to the water level lowering amount is generated without using the embankment. Since the grid-shaped drainage groove has a drain function, consolidation can be promoted.
このとき、最も外側の排水溝に遮水材が設置されてい
るため対象範囲外の周辺地盤の水位低下・沈下等の悪影
響を減少させることができる。At this time, since the water-blocking material is installed in the outermost drainage ditch, it is possible to reduce adverse effects such as water level drop and subsidence of the surrounding ground outside the target range.
また最も外側の排水溝を他の排水溝より深く掘削形成
したり、復水井を設けて揚水した地下水を還流させるこ
とにより、さらに周辺地盤・環境への悪影響を著しく低
減することが可能になる。Further, by forming the outermost drainage trench deeper than other drainage trenches or providing condensate wells to return the pumped groundwater, it is possible to further significantly reduce the adverse effects on the surrounding ground and environment.
（実施例） 以下、本発明の一実施例を図面に基づいて詳細に説明
する。(Example) Hereinafter, one example of the present invention will be described in detail with reference to the drawings.
第１図及び第２図は本発明の平面図及び断面図であ
り、本発明は、先ず初めに粘性土地盤ｎに、第１図に示
すような格子状の排水溝１を薄溝用掘削機Ａで掘削形成
する。1 and 2 are a plan view and a cross-sectional view of the present invention. In the present invention, first, a drainage groove 1 in a grid shape as shown in FIG. Excavate and form with machine A.
薄溝用掘削機Ａは第３図に示すように、下端にパイロ
ットビット3aを装備した左右一対のサイドケーシング３
と、該サイドケーシング３に回転可能に軸支された左右
一対のディスクカッタ５と、前記サイドケーシング３の
中間に設けられ、且つ下端にリバースビット4aを装備す
ると共に、土砂排出用リバース管4bを内蔵したセンター
ケーシング４と、上記パイロットビット3aと、ディスク
カッタ５と、リバースビット4aとの回転駆動源である水
中モータ６とから成っている。As shown in FIG. 3, the thin groove excavator A has a pair of left and right side casings 3 each having a pilot bit 3a at the lower end thereof.
And a pair of left and right disc cutters 5 rotatably supported on the side casing 3 and a reverse bit 4a provided at the lower end of the side casing 3 and provided with a reverse pipe 4b for discharging earth and sand. It is composed of a built-in center casing 4, the pilot bit 3a, a disc cutter 5, and a submersible motor 6 which is a rotational drive source for the reverse bit 4a.
また、前記センターケーシング４はサイドケーシング
３とほぼ同径となっており、左右一対のパイロットビッ
ト3a及びディスクカッタ５は夫々が逆方向に回転するこ
とにより、互に回転トルクを相殺するようになってい
る。Further, the center casing 4 has substantially the same diameter as the side casing 3, and the pair of left and right pilot bits 3a and the disc cutter 5 rotate in opposite directions to cancel the rotational torque. ing.
以上の構成からなる薄溝用掘削機Ａを用いて、第４図
に示すような薄型溝1a及び円形孔1b、1cを粘性土地盤ｎ
の粘性土層n1を貫通して下部透水層n2にいたるまで掘削
する。Using the thin groove excavator A having the above structure, the thin groove 1a and the circular holes 1b and 1c as shown in FIG.
Excavate to the lower permeable layer n 2 through the cohesive soil layer n 1 .
そして、第５図に示すように、該薄型溝1a中央の円形
孔1cを中心として、薄溝用掘削機Ａを90度回転させて掘
削すると、該円形孔1cを中心とする交差した薄型溝1aが
掘削形成される。Then, as shown in FIG. 5, when the thin groove excavator A is rotated by 90 degrees around the circular hole 1c at the center of the thin groove 1a, the thin groove intersects around the circular hole 1c. 1a is excavated and formed.
このように、上記の掘削を順次繰り返すことにより、
格子状に掘削された薄型溝1aと、該薄型溝1aの交差部及
び中途部に掘削された円形孔1b、1cとから成る排水溝１
を掘削形成する。In this way, by repeating the above excavation sequentially,
A drainage groove 1 including a thin groove 1a excavated in a lattice shape, and circular holes 1b and 1c excavated at an intersection and an intermediate portion of the thin groove 1a.
Drilling and forming.
このとき、該排水溝１の間隔ａは、薄溝用掘削機Ａの
ディスクカッタ５の直径φと、パイロットビット3a、3a
の中心間隔ｌとの組合せを適宜選択することにより、任
意に設定することができる。At this time, the distance a between the drain grooves 1 is determined by the diameter φ of the disc cutter 5 of the thin groove excavator A and the pilot bits 3a, 3a.
It can be set arbitrarily by appropriately selecting a combination with the center interval l of.
従って、粘性土地盤ｎの土質定数（特に圧密係数Cvの
値）や設定工期に応じた排水溝１の間隔ａを適宜選択す
ることができる。Therefore, it is possible to appropriately select the soil constant of the cohesive land n (particularly the value of the consolidation coefficient Cv) and the interval a of the drainage grooves 1 according to the set construction period.
尚、前記排水溝１の掘削と共に、該排水溝１の周囲に
適宜数の復水井ｍも掘削しておくとよい。Incidentally, it is advisable to excavate an appropriate number of condensate wells m around the drainage groove 1 along with the excavation of the drainage groove 1.
次に、このように掘削形成された排水溝１における最
も外側の排水溝1Aは第２図に示すように、他の排水溝１
よりも深く掘削形成し、その外側に遮水材７を設置す
る。Next, as shown in FIG. 2, the outermost drainage groove 1A in the drainage groove 1 formed by excavation in this manner is the other drainage groove 1A.
Excavation is formed deeper than that, and the water blocking material 7 is installed on the outer side.
遮水材７としては鋼材と固結性材料との組合せや薄膜
状遮水材等を利用することができる。As the water-impervious material 7, a combination of a steel material and a solidifying material, a thin-film water-impervious material, or the like can be used.
該薄膜状遮水材を利用する場合は、ロール状の薄膜状
遮水材を最も外側の排水溝1Aにおける円形孔1b、1cに挿
入し、該円形孔1b、1cを起点として排水溝1Aの外側の壁
面に張り付けるようにするとよい。When using the thin film waterproof material, the roll-shaped thin waterproof material is inserted into the circular holes 1b and 1c in the outermost drain groove 1A, and the circular holes 1b and 1c are used as starting points for the drain groove 1A. It is good to stick it to the outer wall.
このようにして、最も外側の排水溝1Aに遮水材７を設
置した後、排水溝１における各薄型溝1a及び円形孔1b、
1cに砂、礫、砕石等の透水係数の大きな自然材料や人工
材料を主体とする透水性材料２を充填すると共に、該円
形孔1b、1cに吐出管を連結した水中ポンプＰを適宜間隔
ごとに設置し、該水中ポンプＰにより地下水を強制的に
排水して工事敷地内の地下水位Ｗ（自然水位）を低下さ
せる。また、図中Ｗ′は低下後の地下水位を示す。In this way, after installing the water blocking material 7 in the outermost drainage groove 1A, each thin groove 1a and circular hole 1b in the drainage groove 1,
1c is filled with a water-permeable material 2 mainly composed of a natural material or an artificial material having a large water permeability such as sand, gravel, and crushed stone, and a submersible pump P in which a discharge pipe is connected to the circular holes 1b and 1c is provided at appropriate intervals. The groundwater is forcedly drained by the submersible pump P to lower the groundwater level W (natural water level) in the construction site. W'in the figure indicates the groundwater level after the decrease.
尚、この時強制排水された地下水は、通常、下水道へ
放流するが、前記した工事敷地周囲の復水井ｍへ還流す
ることが望ましい。The groundwater that is forcibly discharged at this time is normally discharged to the sewer, but it is desirable to return it to the condensate well m around the construction site.
このように、粘性土地盤ｎに掘削形成した排水溝１に
おける最も外側の排水溝1Aの外側に遮水材７を設置する
ことにより、地下水位Ｗ（自然水位）の低下が周辺地盤
へ影響するのを防止して、周辺地盤の圧密沈下を防ぐこ
とができる。In this way, by installing the water-blocking material 7 outside the outermost drainage groove 1A in the drainage groove 1 formed by excavation in the cohesive land n, a decrease in the groundwater level W (natural water level) affects the surrounding ground. Can be prevented to prevent consolidation settlement of the surrounding ground.
また、粘性土地盤ｎ中の地下水を、円形孔1b、1cから
強制的に排水して地下水位Ｗ（自然水位）を低下させる
ことにより、該粘性土地盤ｎの圧密を進行させる（第２
図）。Further, the groundwater in the cohesive landbed n is forcibly discharged from the circular holes 1b and 1c to lower the groundwater level W (natural water level), thereby promoting the consolidation of the cohesive landbed n (second
Figure).
さらに、格子状の排水溝１がドレーン機能を発揮する
ため、前記圧密がさらに促進される。Furthermore, since the drainage groove 1 in the form of a grid exerts a drain function, the consolidation is further promoted.
この時の地下水位低下量Δｈと粘性土地盤ｎ内の応力
分布は、第７図の（ａ）及び（ｂ）の模式図に示す如
く、有効応力が増加し、それに応じて地盤強度及び密度
の増大を図ることができる。At this time, the groundwater level decrease Δh and the stress distribution in the cohesive soil n increase in effective stress as shown in the schematic diagrams of (a) and (b) of FIG. Can be increased.
（発明の効果） 本発明は以上の様な構成にしたことにより下記の効果
を有する。(Effects of the Invention) The present invention has the following effects by having the above-mentioned configuration.
粘性土地盤に粘性土層を貫通して下部透水層に到達
し、かつ平面的に連続した格子状の排水溝を形成すると
共に、該排水溝における最も外側の排水溝の全長にわた
って遮水材を設置し、前記排水溝から地下水を強制排水
することにより、載荷盛土を用いずに水位低下量に対応
する圧密現象を生じさせることができる。In the cohesive soil, it penetrates the cohesive soil layer to reach the lower permeable layer, and forms a planar continuous grid-like drainage channel, and a water blocking material is provided over the entire length of the outermost drainage channel in the drainage channel. By installing and forcibly draining groundwater from the drainage ditch, a compaction phenomenon corresponding to the amount of water level drop can be generated without using the embankment.
このとき、格子状の排水溝がドレーン機能を発揮して
圧密を促進させることができると共に、最も外側の排水
溝に設置した遮水材により、対象範囲外の周辺地盤の水
位低下・沈下等の悪影響を減少させることができる。At this time, the grid-shaped drainage groove can perform the drain function to promote consolidation, and the water-blocking material installed in the outermost drainage groove prevents water level drop or subsidence of the surrounding ground outside the target range. The adverse effects can be reduced.
排水溝を格子状の薄型溝と、該薄型溝の交差部及び
中途部に形成された円形孔とから形成したことにより、
該円形孔を揚水井として利用できるので周辺地盤に与え
る悪影響を減少させ、かつ別途に揚水井を掘削・形成す
る必要がなくなる。By forming the drainage groove from a lattice-shaped thin groove and a circular hole formed at an intersection and a midway portion of the thin groove,
Since the circular hole can be used as a pumping well, adverse effects on the surrounding ground are reduced, and it is not necessary to separately excavate and form a pumping well.
最も外側の排水溝を、その他の排水溝よりも深く掘
削形成することにより周辺地盤への悪影響を著しく低減
させることができる。By forming the outermost drainage trench deeper than the other drainage trenches, adverse effects on the surrounding ground can be significantly reduced.
最も外側の排水溝で囲まれた粘性土地盤の外側に復
水井を掘削し、該復水井に前記粘性土地盤内から揚水さ
れた地下水を還流することにより、周辺地盤の地下水位
を維持すると共に、放流水の処理が不要となる。Condensate wells are excavated outside the cohesive ground surrounded by the outermost drainage channels, and the groundwater pumped from within the cohesive ground is returned to the condensate well to maintain the groundwater level of the surrounding ground. Therefore, the treatment of discharged water becomes unnecessary.
第１図は本発明の排水溝の平面図、第２図は同断面図、
第３図は薄溝用掘削機の正面図、第４図は薄型掘削機に
よって形成される排水溝孔の１エレメントを示す正面
図、第５図は排水溝の掘削方法を示す正面図、第６図は
従来の地下水位低下工法の断面図、第７図の（ａ）は本
発明の粘性土地盤の圧密促進工法による増加有効応力を
示す模式図、同図の（ｂ）は改良後の地盤強度を示す模
式図である。 また図中、 1:排水溝 n:粘性土地盤 n1:粘性土層 n2:下部透水層 W:地下水位（自然水位） を示す。FIG. 1 is a plan view of the drainage groove of the present invention, FIG. 2 is a sectional view of the same,
FIG. 3 is a front view of a thin groove excavator, FIG. 4 is a front view showing one element of a drainage hole formed by a thin excavator, and FIG. 5 is a front view showing a method of excavating a drainage groove. Fig. 6 is a cross-sectional view of the conventional groundwater level lowering method, Fig. 7 (a) is a schematic diagram showing the increased effective stress by the consolidation promoting method of the viscous ground of the present invention, and Fig. 6 (b) is the one after improvement. It is a schematic diagram which shows the ground strength. In addition, in the figure, 1: Drainage n: Cohesive soil bed n 1 : Cohesive soil layer n 2 : Lower permeable layer W: Groundwater level (natural water level).
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中川 雅弘 東京都中央区京橋１丁目７番１号 戸田建 設株式会社内 (72)発明者 舘川 裕次 東京都中央区京橋１丁目７番１号 戸田建 設株式会社内 (72)発明者 落合 正水 東京都中央区京橋１丁目７番１号 戸田建 設株式会社内 (72)発明者 窪田 敬昭 東京都中央区京橋１丁目７番１号 戸田建 設株式会社内 (56)参考文献 特開 昭57−205615（ＪＰ，Ａ) 特開 昭61−49017（ＪＰ，Ａ) 特公 昭52−23163（ＪＰ，Ｂ１) ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masahiro Nakagawa 1-7-1, Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Inventor Yuji Tategawa 1-1-7, Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Inventor Masamizu Ochiai 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Inventor Takaaki Kubota 1-1-7 Kyobashi, Chuo-ku, Tokyo (56) References JP-A-57-205615 (JP, A) JP-A-61-49017 (JP, A) JP-B-52-23163 (JP, B1)
Claims (4)
層に到達し、かつ平面的に連続した格子状の排水溝を形
成し、該排水溝からの強制排水によって地下水位を低下
させて前記粘性土層の圧密促進を図る工法であって、前
記排水溝における最も外側の排水溝の全長にわたって遮
水材を設置したことを特徴とする粘性土地盤の圧密促進
工法。1. A ground drainage channel is formed in a cohesive ground by penetrating a cohesive soil layer to reach a lower permeable layer and forming a planar continuous grid drainage channel, and forcibly draining from the drainage channel. A method for promoting the consolidation of the cohesive soil layer, wherein a water-blocking material is installed over the entire length of the outermost drainage channel in the drainage channel, which is a method for promoting consolidation of the cohesive soil layer.
層に到達し、かつ平面的に連続した格子状の排水溝を形
成し、該排水溝からの強制排水によって地下水位を低下
させて前記粘性土層の圧密促進を図る工法であって、前
記排水溝を格子状の薄型溝と、該薄型溝の交差部及び中
途部に形成された円形孔とから形成し、この排水溝にお
ける最も外側の排水溝の全長にわたって遮水材を設置し
たことを特徴とする粘性土地盤の圧密促進工法。2. The groundwater level is lowered in the cohesive ground by penetrating the cohesive soil layer to reach the lower permeable layer and forming a planarly continuous grid-like drainage channel, and forcibly draining from the drainage channel. In the method for promoting the consolidation of the cohesive soil layer, the drainage groove is formed by a lattice-shaped thin groove and circular holes formed at intersections and intermediate portions of the thin groove. A method for promoting consolidation of cohesive land, which is characterized in that a water-blocking material was installed over the entire length of the outermost drainage groove in.
を、その他の排水溝よりも深く掘削形成することを特徴
とする請求項１または２に記載の粘性土地盤の圧密促進
工法。3. The method for promoting consolidation of cohesive land according to claim 1 or 2, wherein the outermost drainage groove provided with the water-blocking material is excavated deeper than the other drainage grooves.
水溝で囲まれた粘性土地盤の外側に復水井を掘削し、該
復水井に前記粘性土地盤内から揚水された地下水を還流
することを特徴とする請求項１、２または３に記載の粘
性土地盤の圧密促進工法。4. A condensate well is excavated on the outside of a cohesive landbed surrounded by the outermost drains in the grid-like drainage channel, and groundwater pumped from inside the cohesive landbed is returned to the condensate well. The method for promoting consolidation of cohesive land according to claim 1, 2, or 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2080916A JPH0826536B2 (en) | 1990-03-30 | 1990-03-30 | Consolidation promotion method for clay ground |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2080916A JPH0826536B2 (en) | 1990-03-30 | 1990-03-30 | Consolidation promotion method for clay ground |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03281817A JPH03281817A (en) | 1991-12-12 |
| JPH0826536B2 true JPH0826536B2 (en) | 1996-03-13 |
Family
ID=13731728
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2080916A Expired - Lifetime JPH0826536B2 (en) | 1990-03-30 | 1990-03-30 | Consolidation promotion method for clay ground |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0826536B2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5223163A (en) * | 1975-08-14 | 1977-02-21 | Sanshin Seinetsu Kogyo Kk | Method of producing spiral synthetic resin tube obliquely laminated |
| JPS6149017A (en) * | 1984-08-13 | 1986-03-10 | Toa Harbor Works Co Ltd | Sand drain work |
-
1990
- 1990-03-30 JP JP2080916A patent/JPH0826536B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03281817A (en) | 1991-12-12 |
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