JP4609794B2 - Soft ground improvement method under permeable upper ground - Google Patents

Soft ground improvement method under permeable upper ground Download PDF

Info

Publication number
JP4609794B2
JP4609794B2 JP2005012454A JP2005012454A JP4609794B2 JP 4609794 B2 JP4609794 B2 JP 4609794B2 JP 2005012454 A JP2005012454 A JP 2005012454A JP 2005012454 A JP2005012454 A JP 2005012454A JP 4609794 B2 JP4609794 B2 JP 4609794B2
Authority
JP
Japan
Prior art keywords
ground
water
drain
permeable
drain material
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.)
Active
Application number
JP2005012454A
Other languages
Japanese (ja)
Other versions
JP2006200204A (en
Inventor
孝 土田
要一 渡部
宏史 米谷
浩二 小野田
博 新舎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
INDEPENDENT ADMINISTRATIVE INSTITUTION PORT AND AIRPORT RESEARCH INSTITUTE
Hiroshima University NUC
Penta Ocean Construction Co Ltd
Original Assignee
INDEPENDENT ADMINISTRATIVE INSTITUTION PORT AND AIRPORT RESEARCH INSTITUTE
Hiroshima University NUC
Penta Ocean Construction Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by INDEPENDENT ADMINISTRATIVE INSTITUTION PORT AND AIRPORT RESEARCH INSTITUTE, Hiroshima University NUC, Penta Ocean Construction Co Ltd filed Critical INDEPENDENT ADMINISTRATIVE INSTITUTION PORT AND AIRPORT RESEARCH INSTITUTE
Priority to JP2005012454A priority Critical patent/JP4609794B2/en
Publication of JP2006200204A publication Critical patent/JP2006200204A/en
Application granted granted Critical
Publication of JP4609794B2 publication Critical patent/JP4609794B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)

Description

本発明は、表層部に廃棄物を堆積させた透水性地盤が存在する軟弱地盤を改良するための透水性上部地盤下の軟弱地盤改良方法に関する。   The present invention relates to a soft ground improvement method under a permeable upper ground for improving a soft ground having a permeable ground with waste deposited on a surface layer portion.

従来、軟弱地盤の改良方法として、バーティカルドレーン工法が広く知られている。この工法は軟弱地盤表面より、縦方向に通水溝を有し、周囲を透水フィルターで覆ったプラスチック製のドレーン材であるプラスチックボードドレーン材を、一定間隔ごとに軟弱地盤表面より地盤中に打ち込み、これを通して軟弱地盤内の水を排出させるようにしたものが広く採用されている。   Conventionally, the vertical drain method is widely known as a method for improving soft ground. In this method, plastic board drain material, which is a plastic drain material with a water flow groove in the vertical direction from the soft ground surface and covered with a permeable filter, is driven into the ground from the soft ground surface at regular intervals. Through this, water that drains the soft ground is widely used.

この従来の軟弱地盤改良工法には、図６に示すようにドレーン材１を打設した軟弱地盤２上に、錘用の積載盛土３を造成し、その荷重によって軟弱地盤を圧密させる載荷圧密工法（例えば特許文献１，２）がある。この工法では、軟弱地盤２の下に透水性基層４が存在している場合には、その透水性基層４までドレーン材１を到達させ、載荷盛土による荷重によってドレーン材1内に流入する水を地表面側のみならず、透水性基層４をも通して排水させるようにしている。   In this conventional soft ground improvement method, as shown in FIG. 6, a loading embankment 3 for weight is formed on the soft ground 2 on which the drain material 1 is placed, and the soft ground is consolidated by the load. (For example, Patent Documents 1 and 2). In this construction method, when the water permeable base layer 4 exists under the soft ground 2, the drain material 1 is made to reach the water permeable base layer 4, and the water flowing into the drain material 1 by the load by the loading embankment is discharged. The water is drained through not only the ground surface side but also the water permeable base layer 4.

また、図７に示すようにドレーン材１を打設した軟弱地盤２の表面を不通気性シート５で被い、各ドレーン材１の上端を減圧装置６に連通させて減圧させることにより、大気圧を地盤表面に載荷させ、これによって排水を促進させる真空圧密工法がある（例えば特許文献３，４）。この工法では軟弱地盤２下に前述した透水性基層４が存在する場合には、減圧による効果を得るためには透水性基層４の水を吸引しないようにする必要があるため、ドレーン材１はその下端が透水性基層４より所定高さだけ高い位置にとどめる必要がある。   Further, as shown in FIG. 7, the surface of the soft ground 2 on which the drain material 1 is placed is covered with an air-impermeable sheet 5, and the upper end of each drain material 1 is communicated with the decompression device 6 to reduce the pressure. There is a vacuum consolidation method in which atmospheric pressure is loaded on the ground surface, thereby promoting drainage (for example, Patent Documents 3 and 4). In this construction method, when the water-permeable base layer 4 described above is present under the soft ground 2, in order to obtain the effect of reduced pressure, it is necessary to prevent the water from the water-permeable base layer 4 from being sucked. It is necessary to keep the lower end at a position higher than the water permeable base layer 4 by a predetermined height.

また、この他、真空圧密工法に載荷盛土を併用した工法も提案されている（例えば特許文献５）。   In addition, a method using a load embankment in combination with a vacuum consolidation method has also been proposed (for example, Patent Document 5).

更に、軟弱地盤の支持力を増強する工法には、上述した排水による圧密によるものの外、セメントミルク等の固化剤を地盤中に注入して攪拌することにより軟弱地盤中に円柱状の高強度部分を形成させる工法がある。
特開平５−１８７０１２号公報 特開平７−１９７４３９号公報 特開２００２−１３８４５６号公報 特開２００３−２６１９３０号公報 特開２００２−５４１３１号公報 Furthermore, in addition to the above-mentioned compaction by drainage, the construction method for enhancing the supporting capacity of soft ground is a columnar high-strength portion in soft ground by injecting a solidifying agent such as cement milk into the ground and stirring. There is a method of forming.
Japanese Patent Laid-Open No. 5-187012 JP-A-7-197439 JP 2002-138456 A JP 2003-261930 A JP 2002-54131 A

近年において、軟弱地盤上に廃棄物を建設残土や砂礫などとともに盛り上げた廃棄物処分場や埋立地が多く存在しており、それらは軟弱地盤上に廃棄物を含む透水性上部地盤が造成されている。近年、それらの廃棄物を含む透水性上部地盤の上に道路などの建造物を構築しなければならない事情が生じつつあるが、これらの多くの場合には、表層部分の透水性上部地盤下の軟弱地盤が、建造物の荷重によって長期間に渡って不均一に沈下してしまうため、事前に軟弱地盤の改良が必要となる。   In recent years, there are many waste disposal sites and landfills where waste is built up on construction ground and gravel on soft ground, and these are the areas where permeable upper ground containing waste is created on soft ground. Yes. In recent years, there has been a situation in which buildings such as roads have to be built on the permeable upper ground containing those wastes. Since soft ground sinks unevenly over a long period due to the load of the building, it is necessary to improve the soft ground beforehand.

このような廃棄物等による透水性上部地盤が存在している軟弱地盤の改良に、前述した載荷圧密工法を適用すると、図８（イ）に示すように、軟弱地盤２上の透水性上部地盤７と透水性基層４との間に、ドレーン材１による水道ができることとなり、地盤改良工事完了後においても透水性上部地盤７内の汚染水が透水性基層４内に流れ込んで地下水を汚染するという問題がある。   When the above-described loading consolidation method is applied to the improvement of the soft ground where the permeable upper ground due to such waste exists, the permeable upper ground on the soft ground 2 as shown in FIG. 7 and the water permeable base layer 4, the water supply by the drain material 1 is made, and even after the ground improvement work is completed, the contaminated water in the water permeable upper ground 7 flows into the water permeable base layer 4 and contaminates the groundwater. There's a problem.

このように透水性上部地盤７内の水が土壌によって浄化されずに透水性基層４内へ流れ込むのをより効果的に防止するためには、図８（ロ）に示すようにドレーン材１の下端と透水性基層４との間の間隔ａを大きくとるようにすればよいが、この間隔ａ分の地盤改良がなされなくなり、改良効果が低下する。   Thus, in order to more effectively prevent the water in the permeable upper ground 7 from flowing into the permeable base layer 4 without being purified by the soil, as shown in FIG. The distance a between the lower end and the water permeable base layer 4 may be increased, but the ground improvement for the distance a is not made, and the improvement effect is lowered.

また、前述した真空圧密工法を適用すると、図９に示すように透水性上部地盤７内の水を排水させることとなって、地盤改良の効率が悪くなる。また、工事完了後に透水性上部地盤７内の水が土壌によって浄化されずに透水性基層４内へ流れ込むのを、より効果的に防止するためには前述と同様に間隔ａを大きく取る必要が生じ、改良効果が低下するという問題が生じる。   Moreover, if the vacuum consolidation method mentioned above is applied, as shown in FIG. 9, the water in the water-permeable upper ground 7 will be drained, and the efficiency of ground improvement will worsen. Further, in order to more effectively prevent the water in the permeable upper ground 7 from flowing into the permeable base layer 4 without being purified by the soil after the construction is completed, it is necessary to increase the interval a as described above. This causes a problem that the improvement effect is reduced.

更に、地盤中に固化剤を注入する工法は、汚染された水を拡散させる恐れはないが、非常にコスト高となるという問題がある。   Furthermore, the method of injecting a solidifying agent into the ground does not have the risk of diffusing contaminated water, but has a problem that it is very expensive.

本発明はこのような従来の問題に鑑み、表層部分に透水性上部地盤が存在する軟弱地盤の改良に際し、透水性上部地盤内の水が、改良工事中にドレーンとして排水されることがなく、また、改良工事中のみならず同工事完了後においても、表層部分の透水性上部地盤の水が地下水層に流れ込むことが無く、更に、軟弱地盤のほぼ全域に亘って改良効果が得られる透水性上部地盤下の軟弱地盤改良方法の提供を目的としてなされたものである。   In view of such a conventional problem, the present invention, when improving the soft ground where there is a permeable upper ground in the surface layer portion, the water in the permeable upper ground is not drained as a drain during the improvement work, In addition, not only during the improvement work but also after the completion of the work, the water in the upper part of the surface layer does not flow into the groundwater layer, and the improvement effect can be obtained over almost the entire soft ground. It was made for the purpose of providing a soft ground improvement method under the upper ground.

上述の如き従来の問題を解決し、所期の目的を達成するための請求項１に記載の発明の特徴は、地表部分に存在する透水性上部地盤と低部の透水性基層との間に存在する軟弱地盤に地表面からドレーン材を挿入し、該軟弱地盤内の土壌間隙水を排水することにより地盤を改良する透水性上部地盤下の軟弱地盤改良方法において、前記ドレーン材は、前記透水性上部地盤深さより所定長さだけ長い撤去部と、該撤去部の下端に分離可能に連結され、該撤去部下端より前記透水性基層から所望の高さだけ高い深さに至るまでの長さを有する埋め捨て部とを備えるとともに、前記撤去部に透水性上部地盤内の水の浸入を防止する不透水部を備え、前記ドレーン材をその埋め捨て部の下端を前記透水性基層まで至らない所望の改良深さまで挿入させ、前記透水性上部地盤及び透水性基層内に水を排水させることなく前記軟弱地盤内の土壌間隙水を該ドレーン材の上端を通して排水させることにより所望の地盤改良を行い、然る後前記ドレーン材の撤去部を地表より除去してなる透水性上部地盤下の軟弱地盤改良方法にある。   In order to solve the above-described conventional problems and achieve the intended purpose, the feature of the invention described in claim 1 is that the permeable upper ground existing in the ground surface part and the permeable base layer in the lower part are provided. In the soft ground improvement method under the permeable upper ground, the drain material is inserted into the existing soft ground from the ground surface, and drains soil pore water in the soft ground to improve the ground. The length from the bottom of the removed part to a depth higher than the permeable base layer by a desired height is connected to the removed part that is longer than the depth of the upper ground by a predetermined length and the lower end of the removed part. And a drainage part that prevents water from entering the permeable upper ground in the removal part, and the drain material does not reach the bottom of the permeable base layer at the lower end of the dumping part. Insert to the desired improved depth, The desired soil improvement is performed by draining the soil interstitial water in the soft ground through the upper end of the drain material without draining the water into the water permeable upper ground and the water permeable base layer. It is in the soft ground improvement method under the permeable upper ground formed by removing the removed part from the ground surface.

請求項２に記載の発明は、請求項１の構成に加え、前記ドレーン材の上端を減圧装置に連結し、該ドレーン材内を減圧させて前記軟弱地盤内の土壌間隙水を吸引させることにより地盤改良を行うことを特徴とする。   In addition to the structure of claim 1, the invention according to claim 2 connects the upper end of the drain material to a decompression device, and decompresses the inside of the drain material to suck the soil pore water in the soft ground. It is characterized by ground improvement.

請求項３に記載の発明は、請求項１又は２の構成に加え、ドレーン材の撤去部として、通水用溝を表裏の長手方向に連続して有する通水溝形成用心材の表裏に、前記通水用溝の開放部を閉鎖する配置に透水性フィルターを固着したプラスチック製のドレーン部材と、薄帯板状又は線状をした引張補強材とを有し、該引張補強材を長手方向に沿って前記ドレーン部材と一体化させたものを使用することを特徴とする。   In addition to the configuration of claim 1 or 2, the invention described in claim 3 is provided on the front and back sides of the core material for forming a water flow groove having continuous water flow grooves in the longitudinal direction of the front and back as the drain material removal portion. A plastic drain member having a water permeable filter fixed in an arrangement for closing the open portion of the water passage groove, and a tensile member made of a ribbon or wire, and the tensile member is longitudinally And the one integrated with the drain member is used.

請求項４に記載の発明は、請求項３の構成に加え、撤去部は、引張補強材を薄帯板状とし、一対のドレーン部材を、前記引張補強材の表裏両面に互いに対称配置に固着してなることを特徴とする。   According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, the removal portion has a tensile reinforcement material in the form of a thin strip, and a pair of drain members are fixed to each other in a symmetrical arrangement on both front and back surfaces of the tensile reinforcement material. It is characterized by becoming.

請求項５に記載の発明は、請求項１〜３又は４の構成に加え、前記不透水部はドレーン材の撤去部の外周の必要長さ部分に気密性の遮水被覆を施すことにより不透水性をもたせることを特徴とする。   According to a fifth aspect of the present invention, in addition to the constitution of the first to third or fourth aspects, the impermeable portion is not formed by applying an airtight water shielding coating to a necessary length portion of the outer periphery of the drain material removal portion. It is characterized by having water permeability.

本発明に係る透水性上部地盤下の軟弱地盤改良方法は、地表部分に存在する透水性上部地盤と低部の透水性基層との間に存在する軟弱地盤に地表面からドレーン材を挿入し、該軟弱地盤内の土壌間隙水を排水することにより地盤を改良する透水性上部地盤下の軟弱地盤改良方法において、前記ドレーン材は、前記透水性上部地盤深さより所定長さだけ長い撤去部と、該撤去部の下端に分離可能に連結され、該撤去部下端より前記透水性基層から所望の高さだけ高い深さに至るまでの長さを有する埋め捨て部とを備えるとともに、前記撤去部に透水性上部地盤内の水の浸入を防止する不透水部を備え、前記ドレーン材をその埋め捨て部の下端を前記透水性基層まで至らない所望の改良深さまで挿入させ、前記透水性上部地盤及び透水性基層内に水を排水させることなく前記軟弱地盤内の土壌間隙水を該ドレーン材の上端を通して排水させることにより所望の地盤改良を行い、然る後前記ドレーン材の撤去部を地表より除去することによって、地盤改良中においては、ドレーンとして透水性上部地盤内の水が透水性基層に排水されず、地盤改良後においては、埋め捨てられたドレーン材と透水性上部地盤との間の距離を十分に取ることができ、下水層に浄化されずに流れ込むことが無い。   The soft ground improvement method under the water permeable upper ground according to the present invention is to insert a drain material from the ground surface into the soft ground existing between the water permeable upper ground existing in the ground surface portion and the low water permeable base layer, In the soft ground improvement method under the permeable upper ground that improves the ground by draining the soil pore water in the soft ground, the drain material has a removal portion that is longer than the permeable upper ground depth by a predetermined length, and The removable portion is detachably connected to the lower end of the removal portion and includes a buried portion having a length from the lower end of the removal portion to a depth higher than the water permeable base layer by a desired height. An impermeable portion that prevents infiltration of water in the permeable upper ground, the drain material is inserted at the lower end of the buried portion to a desired improved depth that does not reach the permeable base layer, and the permeable upper ground and Within the water permeable substrate The ground improvement is performed by draining the soil pore water in the soft ground without draining it through the upper end of the drain material, and then removing the drained portion of the drain material from the ground surface. Inside, the water in the permeable upper ground is not drained to the permeable base layer as a drain, and after the ground improvement, a sufficient distance between the drained drain material and the permeable upper ground may be taken. Yes, it does not flow into the sewer without being purified.

前記ドレーン材の上端を減圧装置に連結し、該ドレーン材内を減圧させて前記軟弱地盤内の土壌間隙水を吸引させることにより地盤改良を行うことによって、ドレーン材の下端部から透水性基層に至るまでの距離を必要最小限の距離としてもドレーンとして透水性上部地盤内の水が透水性基層に排水されず、改良対象である軟弱地盤全体を好適に地盤改良（圧密）することができる。   By connecting the upper end of the drain material to a decompression device, reducing the pressure inside the drain material and sucking soil pore water in the soft ground, the ground improvement is performed, so that the drain material has a lower permeable base layer. Even if the distance up to the required minimum distance, water in the permeable upper ground is not drained to the permeable base layer as a drain, and the entire soft ground to be improved can be suitably improved (consolidated).

ドレーン材の撤去部として、通水用溝を表裏の長手方向に連続して有する通水溝形成用心材の表裏に、前記通水用溝の開放部を閉鎖する配置に透水性フィルターを固着したプラスチック製のドレーン部材と、薄帯板状又は線状をした引張補強材とを有し、該引張補強材を長手方向に沿って前記ドレーン部材と一体化させたものを使用することにより、地盤の圧密工程が終了した後、好適にドレーン材の撤去部のみを地盤より引き抜くことができる。   As the drainage part of the drain material, a water permeable filter was fixed on the front and back of the water flow groove forming core material having the water flow grooves continuously in the longitudinal direction of the front and back surfaces in an arrangement for closing the open part of the water flow groove. By using a drain member made of plastic and a tensile reinforcing material in the form of a strip or wire, and by integrating the tensile reinforcing material with the drain member along the longitudinal direction, After the consolidation step is completed, only the drain material removal portion can be preferably pulled out from the ground.

撤去部は、引張補強材を薄帯板状とし、一対のドレーン部材を、前記引張補強材の表裏両面に互いに対称配置に固着してなることにより、ＰＢＤ材の表裏面部より好適に排水を行うことができる。   The removal portion is formed of a ribbon-like tensile reinforcing material, and a pair of drain members are fixed to each other in a symmetrical arrangement on both the front and back surfaces of the tensile reinforcing material, so that drainage is suitably performed from the front and back portions of the PBD material. be able to.

前記不透水部はドレーン材の撤去部の外周の必要長さ部分に気密性の遮水被覆を施すことにより不透水性をもたせることによって、透水性フィルター表面等にも好適に不透水部を形成することができる。   The water-impermeable portion is formed on the surface of the water-permeable filter and the like by providing a water-impervious water-impervious coating on the required length of the outer periphery of the drain material removal portion. can do.

次に本発明の実施の形態を図面に示した実施例に基づいて説明する。尚、上述の従来例と同一の部分には同一符号を付して説明を省略する。   Next, embodiments of the present invention will be described based on examples shown in the drawings. In addition, the same code | symbol is attached | subjected to the part same as the above-mentioned prior art example, and description is abbreviate | omitted.

図１は、本発明方法においてドレーン材を透水性上部地盤７、軟弱地盤２及び透水性基層２からなる地盤に挿入し、減圧手段に連通させた状態を示し、図中符号１０はドレーン材である。   FIG. 1 shows a state in which a drain material is inserted into a ground composed of a water permeable upper ground 7, a soft ground 2 and a water permeable base layer 2 in the method of the present invention and communicated with a decompression means. is there.

この地盤は、地表部分に存在する透水性上部地盤７と、低部の透水性基礎４と、透水性上部地盤７と透水性基礎４との間に存在する軟弱地盤２とをもって構成されている。   This ground is composed of a permeable upper ground 7 present on the ground surface portion, a lower permeable foundation 4, and a soft ground 2 existing between the permeable upper ground 7 and the permeable foundation 4. .

尚、以下の説明における各数値は、透水性上部地盤７の各地盤条件が、地盤層厚９ｍ、単位体積重量γ＝１４ｋＮ／ｍ３（上層）、γ＝２０ｋＮ／ｍ３（中層）、γ＝１０ｋＮ／ｍ３（下層）、周面摩擦力ｆｉ＝−０．８２Ｚ−１．２５（Ｚ：深度（ＧＬ−ｍ））である場合、軟弱地盤２の各地盤条件が、地盤層厚２０ｍ、飽和単位体積重量γｓａｔ＝１５ｋＮ／ｍ３、圧密後単位体積重量γ’＝５ｋＮ／ｍ３、圧密係数ｃｖ＝１００ｃｍ２／ｄａｙ、原地盤粘着力ｃ＝−５．０−２．５ｚ（ｚ：標高（Ｃ．Ｄ．Ｌ．±ｍ））、強度増加率ｃｕ／ｐ＝０．３である場合を例として説明する。 In addition, each numerical value in the following explanation is that each ground condition of the permeable upper ground 7 is ground layer thickness 9 m, unit volume weight γ = 14 kN / m 3 (upper layer), γ = 20 kN / m 3 (middle layer), γ = 10 kN / m 3 (lower layer), peripheral surface friction force fi = −0.82Z−1.25 (Z: depth (GL-m)), the local ground condition of the soft ground 2 is the ground layer thickness 20 m. , Saturated unit volume weight γ sat = 15 kN / m 3 , post-consolidation unit volume weight γ ′ = 5 kN / m 3 , consolidation coefficient cv = 100 cm 2 / day, raw ground adhesive force c = −5.0−2.5 z ( A case where z is the altitude (CDL ± m)) and the intensity increase rate is cu / p = 0.3 will be described as an example.

ドレーン材１０には、例えば、図２、図３に示す如き、プラスチックボードドレーン材（以下ＰＢＤ材という）を使用する。   As the drain material 10, for example, a plastic board drain material (hereinafter referred to as a PBD material) as shown in FIGS. 2 and 3 is used.

このＰＢＤ材１０には、一対のドレーン部材１１，１２が薄帯板状の引張補強材１３の表裏両面に互いに対称配置に固着されている。   A pair of drain members 11, 12 are fixed to the PBD material 10 symmetrically on both the front and back surfaces of a thin strip-like tensile reinforcement member 13.

また、このＰＢＤ材１０は、一対のドレーン部材１１，１２を引張補強材１３の表裏両面に互いに対称配置に固着してなる撤去部１４と、いずれか一方のドレーン部材１１の下端に連続配置に接続されたドレーン部材１５からなる埋め捨て部とをもって構成し、撤去部１４と埋め捨て部とは、ドレーン打設作業時に作用する通常の引張力によっては離れず、撤去する際の抜去力によって離れるようになっている。   Further, the PBD material 10 has a pair of drain members 11, 12 continuously attached to the front and back surfaces of the tensile reinforcement member 13 in a symmetrical arrangement with each other, and a continuous arrangement at the lower end of one of the drain members 11. The removal portion 14 and the burying portion are not separated by the normal tensile force acting during the drain placing operation, but are separated by the removal force at the time of removal. It is like that.

引張補強材１３は、ポリオレフィン系の合成樹脂材を延伸してシート状に成形したプラスチック帯状体やステンレス板等の金属板等をもって構成され、長手方向即ちドレーン材の引き抜き方向に作用する荷重に対して高い強度を備えている。   The tensile reinforcement member 13 is composed of a plastic strip formed by stretching a polyolefin-based synthetic resin material into a sheet shape, a metal plate such as a stainless steel plate, and the like, and is applied to a load acting in the longitudinal direction, that is, the draining direction of the drain material. And has high strength.

この引張補強材１３の表裏に合成樹脂ラミネート層１７等の貼着層を介してドレーン部材１１，１２が固着される。   The drain members 11 and 12 are fixed to the front and back surfaces of the tensile reinforcement member 13 via an adhesive layer such as a synthetic resin laminate layer 17.

ドレーン部材１１，１２，１５は、表裏に長手方向に通水用溝１８，１９を有する通水溝形成用心材２０と、通水溝形成用心材２０の表裏両面を覆う透水性フィルター２１，２１とを備え、通水溝形成用心材２０の表裏面にそれぞれ通水性フィルター２１，２１が固着されている。   The drain members 11, 12, and 15 include a water passage groove forming core member 20 having water passage grooves 18 and 19 in the longitudinal direction on the front and back sides, and water permeable filters 21 and 21 that cover both front and back surfaces of the water passage groove forming core member 20. The water-permeable filters 21 and 21 are respectively fixed to the front and back surfaces of the water-groove forming core material 20.

通水溝形成用心材２０は、互いに対向して平行に配置された複数の縦壁材２２，２２…と、各縦壁材２２，２２間に配された横壁材２３，２３とを備え、断面形状において横壁材２３，２３が千鳥状に配置されたことによって、通水溝形成用心材２０の表裏にそれぞれ浅通水用溝１８と深通水用溝１９とが交互に並んで形成されている。   The water flow groove forming core member 20 includes a plurality of vertical wall members 22, 22... Arranged in parallel and facing each other, and horizontal wall members 23, 23 arranged between the vertical wall members 22, 22. In the cross-sectional shape, the horizontal wall members 23 and 23 are arranged in a staggered manner, so that the shallow water passage grooves 18 and the deep water passage grooves 19 are alternately formed on the front and back surfaces of the water passage groove forming core material 20. ing.

透水性フィルター２１は、ポリエステル系合成繊維からなる不織布をもって透水性を有するシート状に形成されている。   The water permeable filter 21 is formed in a sheet shape having water permeability with a nonwoven fabric made of polyester synthetic fibers.

撤去部１４を構成するドレーン部材１１と埋め捨て部を構成するドレーン部材１５とは、ドレーン部材１１の下端部に埋め捨て部を構成するドレーン部材１５を連続配置し、その互いに突き合わされた端部間の表面に接続用当て板２４を架け渡し、接続用当て板２４にそれぞれドレーン部材１１，１５を固定することにより、埋め捨て部の上端が撤去部１４の下端に対して、ドレーン材打設作業時に作用する通常の引張力によっては離れないが、撤去部１４を撤去する際の抜去力によって離れるようになっている。   The drain member 11 that constitutes the removal portion 14 and the drain member 15 that constitutes the burying portion are arranged such that the drain member 15 constituting the burying portion is continuously arranged at the lower end portion of the drain member 11, and the end portions that are abutted against each other By connecting the contact plate 24 to the surface between them and fixing the drain members 11, 15 to the connection plate 24, the upper end of the buried portion is placed against the lower end of the removal portion 14. Although it does not leave | separate by the normal tensile force which acts at the time of an operation | work, it leaves | separates by the extraction force at the time of removing the removal part 14. FIG.

尚、連結された両ドレーン部材１１，１５の連結部間には、外周に密封処理が施されており、両ドレーン部材１１，１５の通水断面は互いに好適に連通されている。   In addition, between the connection part of the connected drain members 11 and 15, the outer periphery is sealed, and the water flow sections of the drain members 11 and 15 are preferably communicated with each other.

この方法において使用するドレーン材１０は、工場において、撤去部１４の長さを、透水性上部地盤７の厚みより所定の長さだけ長く、即ちドレーン材１０を地盤に挿入した際に、透水性上部地盤７下より所定の長さｃ（約５ｍ）だけ突出する長さ（約１４ｍ）に形成し、埋め捨て部を構成するドレーン部材１５の長さを、ドレーン材１０を地盤に挿入した際に、撤去部１４の下端から、透水性基層４より所望の高さａ（約１ｍ〜２ｍ）だけ高い深さに至る長さ（約１３〜１４ｍ）に予め形成し、その撤去部１４及び埋め捨て部１５を連結して形成しておく。   In the drain material 10 used in this method, the length of the removal portion 14 is longer than the thickness of the water permeable upper ground 7 by a predetermined length in the factory, that is, when the drain material 10 is inserted into the ground. When the drain member 10 is formed to have a length (about 14 m) protruding from the lower ground 7 by a predetermined length c (about 5 m), and the drain member 15 constituting the buried portion is inserted into the ground In addition, a length (about 13 to 14 m) is formed in advance from the lower end of the removal portion 14 to a depth higher than the water permeable base layer 4 by a desired height a (about 1 to 2 m). The discard part 15 is connected and formed.

また、このドレーン材１０には、撤去部１４の上部、即ち撤去部上端から透水性上部地盤７下より稍突出する位置に至るまでの長さ部分に透水性上部地盤７内の水の侵入を防止する不透水部５０を備える。   In addition, the drain material 10 has an intrusion of water in the permeable upper ground 7 into the upper part of the removal part 14, that is, the length from the upper end of the removal part to a position protruding from the bottom of the permeable upper ground 7. A water-impermeable portion 50 is provided.

尚、不透水部５０は、ドレーン材撤去部１４の外周の必要長さ部分、即ち、撤去部上端から透水性上部地盤下より稍突出する位置に至るまでの長さ部分に合成樹脂コーティング等により気密性の遮水被覆を施すことにより不透水性を持たせるようになっている。   In addition, the impermeable portion 50 is formed by a synthetic resin coating or the like on a necessary length portion of the outer periphery of the drain material removing portion 14, that is, a length portion from the upper end of the removing portion to a position protruding from the bottom of the permeable upper ground. By applying an airtight water shielding coating, it is made impermeable.

このように構成されたドレーン材１０を他のドレーン材１０の下端部に接続して多数のドレーン材１０，１０…を一本の帯状に連結し、これをリール５１に巻き取っておき、それを施工現場に搬入するようになっている。   The drain material 10 configured in this way is connected to the lower end of another drain material 10 to connect a large number of drain materials 10, 10... It is designed to be carried on site.

次に、上述の如きドレーン材を用いた本発明方法について説明する。   Next, the method of the present invention using the drain material as described above will be described.

まず、ドレーン材打設位置の透水性上部地盤７を先行削孔機（アースオーガ）により削孔し、そこにドレーン材打設装置５２を用いてドレーン材１０を打設する。   First, the permeable upper ground 7 at the drain material placement position is drilled by a prior drilling machine (earth auger), and the drain material 10 is placed there using the drain material placement device 52.

このドレーン材１０の打設は、例えば、図４に示すように、リール５１に巻かれたドレーン材１０をドレーン材打設用管体（マンドレル）５３内に上端部側より引き込み、下端より突出したドレーン材１０の下端、即ちドレーン部材１５の先端部にアンカープレート５４を取り付け、ドレーン材１０をマンドレル５３ごと地盤内に静的に圧入し、所定の深さまで到達した後、マンドレル５３を引き抜くことにより、先端に取り付けたアンカープレート５４によりその位置に固定されたドレーン材１０のみが地盤内に留まり、ドレーン材１０が所定位置に打設される。   For example, as shown in FIG. 4, the drain material 10 is placed in such a manner that the drain material 10 wound around the reel 51 is drawn into the drain material placement tube (mandrel) 53 from the upper end side and protrudes from the lower end. The anchor plate 54 is attached to the lower end of the drain material 10, that is, the tip of the drain member 15, the drain material 10 is statically pressed into the ground together with the mandrel 53, and after reaching a predetermined depth, the mandrel 53 is pulled out. Thus, only the drain material 10 fixed at that position by the anchor plate 54 attached to the tip remains in the ground, and the drain material 10 is driven in a predetermined position.

このマンドレル５３を引き抜く際に、ドレーン材１０の撤去部１４と埋め捨て部１５との接続部分に引張力が発生するが、この程度の引張力によっては撤去部１４と埋め捨て部１５とは離れないようになっている。   When the mandrel 53 is pulled out, a tensile force is generated at the connection portion between the removal portion 14 and the buried portion 15 of the drain material 10, but the removal portion 14 and the buried portion 15 are separated depending on such a tensile force. There is no such thing.

そして、各ドレーン材間の接続部を切断し、所定の位置、即ち埋め捨て部の下端が透水性基層４まで至らず、透水性基層４より距離ａ（約１〜２ｍ）だけ高い深さであり、且つ撤去部１４の下端が透水性上部地盤７下所定の距離ｃ（約５ｍ）だけ突出した深さであり、更に、不透水部５０の下端が透水性上部地盤７下距離ｂ（約１．５ｍ）だけ突出した深さである位置にドレーン材が打設される。   And the connection part between each drain material is cut | disconnected, and the predetermined position, ie, the lower end of a buried part, does not reach to the water permeable base layer 4, but is a depth higher than the water permeable base layer 4 by a distance a (about 1 to 2 m). There is a depth at which the lower end of the removal portion 14 protrudes by a predetermined distance c (about 5 m) below the permeable upper ground 7, and the lower end of the impermeable portion 50 is a distance b below the permeable upper ground 7 (about The drain material is placed at a position that is a depth protruding by 1.5 m).

各ドレーン材１０，１０…は、所定の間隔をおいて配置され、各ドレーン材１０の上端には、図１に示すように、気密性キャップ５５を固着させ、この気密性キャップ５５の頂部に予めホースからなる排水用材５６を一体に連結しておき、この排水用材５６を集水管を介して減圧手段たる真空ポンプ５７に連通させる。   The drain members 10, 10... Are arranged at predetermined intervals, and an airtight cap 55 is fixed to the upper end of each drain member 10 as shown in FIG. A drainage material 56 made of a hose is connected in advance, and the drainage material 56 is communicated with a vacuum pump 57 as decompression means via a water collecting pipe.

この状態で、真空ポンプ５７を動作させ、真空圧密工法又は、必要に応じて真空圧密工法と戴荷圧密工法を併用する等して軟弱地盤２の地盤改良を行う。   In this state, the vacuum pump 57 is operated, and the ground improvement of the soft ground 2 is performed by using a vacuum consolidation method or using a vacuum consolidation method and a loading consolidation method as necessary.

この際、軟弱地盤２中の土壌間隙水は真空ポンプ５７によって吸い上げられ、軟弱地盤２中の水が透水性基層４に排水されることがないので、ドレーン材１０の下端、即ち埋め捨て部を構成するドレーン部材１５の先端から透水性基層４までの距離ａが必要最小限の距離確保されていればよく、軟弱地盤２のほぼ全域に亘って好適に地盤改良効果を得ることができる。   At this time, the soil interstitial water in the soft ground 2 is sucked up by the vacuum pump 57 and the water in the soft ground 2 is not drained to the water permeable base layer 4. The required minimum distance a from the tip of the drain member 15 to be configured to the water permeable base layer 4 is ensured, and the ground improvement effect can be suitably obtained over almost the entire area of the soft ground 2.

また、透水性上部地盤７内の水は、不透水部５０により遮水され、排水されないので、効率良く地盤改良を行うことができ、透水性上部地盤７内の汚水が排水に混じらないため、その浄化処理も不要となる。   Moreover, since the water in the permeable upper ground 7 is blocked by the impermeable portion 50 and is not drained, the ground can be improved efficiently, and the sewage in the permeable upper ground 7 is not mixed with the drainage. The purification process is also unnecessary.

地盤改良終了後、減圧手段や必要に応じて戴荷用の盛土等を撤去する。しかし、不透水部５０の透水性上部地盤７下より突出した距離ｂ（約１．５ｍ）は、軟弱地盤２全体で圧密が行われるようにする為必要最低限の長さとなっており、その為、地盤改良が終了し、真空ポンプ５７による排水が行われていない状態では、透水性上部地盤７内の汚水がドレーン材１０の不透水部５０下の部分より排水され、ドレーン材１０を通して土壌によって浄化されることなく透水性基層４内へ流れ込んでしまう。   After the ground improvement is completed, the decompression means and the embankment for loading will be removed if necessary. However, the distance b (about 1.5 m) protruding from the bottom of the water-permeable upper ground 7 of the water-impermeable portion 50 is the minimum length necessary for the consolidation of the soft ground 2 as a whole. Therefore, in the state where the ground improvement is completed and the drainage by the vacuum pump 57 is not performed, the sewage in the permeable upper ground 7 is drained from the portion below the impermeable portion 50 of the drain material 10, and the soil is passed through the drain material 10. Will flow into the water permeable base layer 4 without being purified.

そこで、ドレーン材１０の撤去部１４を地盤より引き抜き、透水性上部地盤７とドレーン材１０との間の距離ｃを大きくとることにより、透水性上部地盤７内の汚水が土壌によって浄化されることなく透水性基層４内へ流れ込むのを防止する。   Therefore, by removing the removed portion 14 of the drain material 10 from the ground and increasing the distance c between the permeable upper ground 7 and the drain material 10, the sewage in the permeable upper ground 7 is purified by the soil. Without flowing into the water permeable base layer 4.

ドレーン材１０の撤去は、図５に示すように、ドレーン材１０の上端部を挟持した状態で引き抜き装置３０により引き上げることにより行う。   As shown in FIG. 5, the drain material 10 is removed by pulling up the drain material 10 while holding the upper end portion of the drain material 10.

この引き抜き装置３０は、ドレーン材１０を挟持するチャック３１と、チャック３１に引き上げ力を与える引き上げ駆動部材３２とを有し、チャック３１にドレーン材１０の上端部を挟持させ、そのチャック３１を引き上げ駆動部材３２により引き上げることによりＰＢＤ材１０を地盤より引き抜くようになっている。   The pulling device 30 includes a chuck 31 that holds the drain material 10 and a pulling drive member 32 that applies a pulling force to the chuck 31. The chuck 31 holds the upper end portion of the drain material 10 and lifts the chuck 31. The PBD material 10 is pulled out from the ground by being pulled up by the drive member 32.

引き上げ駆動部材３２は、クレーン３３より繰出された吊りワイヤ３４を支持リーダ３５に支持された滑車を通して吊り降ろさせ、その吊りワイヤ３４の先端にチャック３１を取り付けておき、クレーン３３により吊りワイヤ３４を巻取ることにより、チャック３１に引き上げ力を与えることができるようになっている。   The pulling drive member 32 suspends the suspension wire 34 fed from the crane 33 through a pulley supported by the support leader 35, attaches a chuck 31 to the tip of the suspension wire 34, and uses the crane 33 to suspend the suspension wire 34. A lifting force can be applied to the chuck 31 by winding.

このようにすることによって、ドレーン材１０は、撤去部１４と埋め捨て部１５との接続部分に所定の荷重以上の抜去力が作用することによって撤去部１４と埋め捨て部１５とが分離して、埋め捨て部１５が軟弱地盤２中に留まり、撤去部１４のみが地盤より引き抜かれ、透水性上部地盤７と埋め捨て部との間に浄化に十分な距離ｃが形成されるようになっている。   By doing in this way, in the drain material 10, the removal part 14 and the dumping part 15 are separated by the removal force of a predetermined load or more acting on the connection part between the removal part 14 and the dumping part 15. The buried portion 15 stays in the soft ground 2 and only the removed portion 14 is pulled out from the ground, and a sufficient distance c for purification is formed between the permeable upper ground 7 and the buried portion. Yes.

尚、上述の実施例では、地盤改良を真空圧密工法又は真空圧密工法と戴荷圧密工法とを併用して行う例について説明したが、その他、バーティカルドレーン工法によるものであればよい。   In the above-described embodiment, the example in which the ground improvement is performed using the vacuum consolidation method or the vacuum consolidation method and the loading consolidation method is described. However, any other method may be used as long as it is based on the vertical drain method.

また、ドレーン材は、上述の実施例で示すものに限定されず、撤去部を、薄帯板状に形成された引張補強材の片面にのみドレーン部材を固着させて形成したもの等であってもよい。   Further, the drain material is not limited to the one shown in the above-described embodiment, and the removal portion is formed by fixing the drain member only to one surface of the tensile reinforcing material formed in a thin strip shape. Also good.

本発明方法におけるドレーン材の設置状態を示す断面図である。It is sectional drawing which shows the installation state of the drain material in this invention method. 図１中のドレーン材を示す側面図である。It is a side view which shows the drain material in FIG. 同上のドレーン材の部分拡大横断面図である。It is a partial expanded cross-sectional view of the same drain material. 本発明方法のドレーン材打設作業の状態を示す側面図である。It is a side view which shows the state of the drain material placement operation | work of this invention method. 同上のドレーン材の撤去作業の状態を示す側面図である。It is a side view which shows the state of removal work of a drain material same as the above. 従来の戴荷圧密工法による地盤改良の概略を示す断面図である。It is sectional drawing which shows the outline of the ground improvement by the conventional loading consolidation method. 従来の真空圧密工法による地盤改良の概略を示す断面図である。It is sectional drawing which shows the outline of the ground improvement by the conventional vacuum consolidation method. 戴荷圧密工法における問題点を説明する為の断面図である。It is sectional drawing for demonstrating the problem in a loading compaction construction method. 真空圧密工法における問題点を説明するための断面図である。It is sectional drawing for demonstrating the problem in a vacuum consolidation method.

符号の説明Explanation of symbols

２ 軟弱地盤
４ 透水性基層
７ 透水性上部地盤
１０ ドレーン材（ＰＢＤ材）
１１，１２ ドレーン部材
１３ 引張補強材
１４ 撤去部
１５ ドレーン材（埋め捨て部）
１７ ラミネート層
１８ 浅通水用溝
１９ 深通水用溝
２０ 通水溝形成用心材
２１ 透水性フィルター
２２ 縦壁材
２３ 横壁材
２４ 接続用当て板
５０ 不透水部
５１ リール
５２ ドレーン材打設装置
５３ ドレーン材打設用管体（マンドレル）
５４ アンカープレート
５５ 気密性キャップ
５６ 排水用材
５７ 真空ポンプ 2 Soft ground 4 Permeable base layer 7 Permeable upper ground 10 Drain material (PBD material)
11, 12 Drain member 13 Tensile reinforcement 14 Removed part 15 Drain material (filled part)
DESCRIPTION OF SYMBOLS 17 Laminate layer 18 Shallow water channel 19 Deep water channel 20 Water channel forming core material 21 Permeable filter 22 Vertical wall material 23 Horizontal wall material 24 Connection pad 50 Impervious part 51 Reel 52 Drain material placing device 53 Drain material placement tube (mandrel)
54 Anchor plate 55 Airtight cap 56 Drainage material 57 Vacuum pump

Claims (5)

地表部分に存在する透水性上部地盤と低部の透水性基層との間に存在する軟弱地盤に地表面からドレーン材を挿入し、該軟弱地盤内の土壌間隙水を排水することにより地盤を改良する透水性上部地盤下の軟弱地盤改良方法において、
前記ドレーン材は、前記透水性上部地盤深さより所定長さだけ長い撤去部と、該撤去部の下端に分離可能に連結され、該撤去部下端より前記透水性基層から所望の高さだけ高い深さに至るまでの長さを有する埋め捨て部とを備えるとともに、前記撤去部に透水性上部地盤内の水の浸入を防止する不透水部を備え、前記ドレーン材をその埋め捨て部の下端を前記透水性基層まで至らない所望の改良深さまで挿入させ、前記透水性上部地盤及び透水性基層内に水を排水させることなく前記軟弱地盤内の土壌間隙水を該ドレーン材の上端を通して排水させることにより所望の地盤改良を行い、然る後前記ドレーン材の撤去部を地表より除去することを特徴としてなる透水性上部地盤下の軟弱地盤改良方法。 Improve the ground by inserting drainage material from the ground surface into the soft ground existing between the permeable upper ground existing on the ground surface and the lower permeable base layer, and draining the soil pore water in the soft ground. In the soft ground improvement method under the permeable upper ground,
The drain material is detachably connected to a removal part longer than the depth of the water permeable upper ground by a predetermined length and a lower end of the removal part, and has a depth higher than the water permeable base layer by a desired height from the lower end of the removal part. And a buried portion having a length up to a length, and an impermeable portion for preventing infiltration of water in the permeable upper ground to the removed portion, and the drain material is disposed at a lower end of the buried portion. Inserting to a desired improved depth not reaching the water permeable base layer, draining the soil pore water in the soft ground through the upper end of the drain material without draining water into the water permeable upper ground and the water permeable base layer A method for improving the soft ground under the permeable upper ground, characterized in that the desired ground improvement is performed, and then the drained portion of the drain material is removed from the ground surface. 前記ドレーン材の上端を減圧装置に連結し、該ドレーン材内を減圧させて前記軟弱地盤内の土壌間隙水を吸引させることにより地盤改良を行う請求項１に記載の透水性上部地盤下の軟弱地盤改良方法。   The softness under the permeable upper ground according to claim 1, wherein the upper end of the drain material is connected to a decompression device, and the soil is improved by reducing the pressure in the drain material and sucking in the soil pore water in the soft ground. Ground improvement method. ドレーン材の撤去部として、通水用溝を表裏の長手方向に連続して有する通水溝形成用心材の表裏に、前記通水用溝の開放部を閉鎖する配置に透水性フィルターを固着したプラスチック製のドレーン部材と、薄帯板状又は線状をした引張補強材とを有し、該引張補強材を長手方向に沿って前記ドレーン部材と一体化させたものを使用する請求項１又は２に記載の透水性上部地盤下の軟弱地盤改良方法。   As the drainage part of the drain material, a water permeable filter was fixed on the front and back of the water flow groove forming core material having the water flow grooves continuously in the longitudinal direction of the front and back surfaces in an arrangement for closing the open part of the water flow groove. 2. A plastic drain member and a ribbon-like or linear tensile reinforcement member, wherein the tensile reinforcement member is integrated with the drain member along the longitudinal direction. The soft ground improvement method under the water-permeable upper ground according to 2. 引張補強材を薄帯板状とし、一対のドレーン部材を、前記引張補強材の表裏両面に互いに対称配置に固着してなる請求項３に記載の透水性上部地盤下の軟弱地盤改良方法。   The method for improving soft ground under a water-permeable upper ground according to claim 3, wherein the tensile reinforcing material is in the form of a thin strip, and a pair of drain members are fixed to each other in a symmetrical arrangement on both the front and back surfaces of the tensile reinforcing material. 前記不透水部はドレーン材の撤去部の外周の必要長さ部分に気密性の遮水被覆を施すことにより不透水性を持たせる請求項１〜３又は４に記載の透水性上部地盤下の軟弱地盤改良方法。   The impermeable portion according to claim 1, wherein the impermeable portion is made impermeable by applying an airtight water shielding coating to a necessary length portion of the outer periphery of the drain material removal portion. Soft ground improvement method.
JP2005012454A 2005-01-20 2005-01-20 Soft ground improvement method under permeable upper ground Active JP4609794B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2005012454A JP4609794B2 (en) 2005-01-20 2005-01-20 Soft ground improvement method under permeable upper ground

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2005012454A JP4609794B2 (en) 2005-01-20 2005-01-20 Soft ground improvement method under permeable upper ground

Publications (2)

Publication Number Publication Date
JP2006200204A JP2006200204A (en) 2006-08-03
JP4609794B2 true JP4609794B2 (en) 2011-01-12

Family

ID=36958445

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2005012454A Active JP4609794B2 (en) 2005-01-20 2005-01-20 Soft ground improvement method under permeable upper ground

Country Status (1)

Country Link
JP (1) JP4609794B2 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5767829B2 (en) * 2011-03-03 2015-08-19 五洋建設株式会社 Vacuum consolidation drain method and drain material
JP6206920B2 (en) * 2014-01-20 2017-10-04 株式会社不動テトラ Ground injection board and ground injection method using the same
JP6605856B2 (en) * 2015-06-29 2019-11-13 東亜建設工業株式会社 Drain material placement method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01174427U (en) * 1988-05-20 1989-12-12
JP2000230229A (en) * 1999-02-12 2000-08-22 Shimizu Corp Ground improving method
JP2003232029A (en) * 2002-02-07 2003-08-19 Ohbayashi Corp Simulation analysis method for vacuum consolidation method
JP2006509129A (en) * 2002-12-05 2006-03-16 バガーマアトシュアピジ ボスカリス ベー．ファオ． Soil drainage system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2625614B2 (en) * 1992-07-24 1997-07-02 五洋建設株式会社 Drain material placement method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01174427U (en) * 1988-05-20 1989-12-12
JP2000230229A (en) * 1999-02-12 2000-08-22 Shimizu Corp Ground improving method
JP2003232029A (en) * 2002-02-07 2003-08-19 Ohbayashi Corp Simulation analysis method for vacuum consolidation method
JP2006509129A (en) * 2002-12-05 2006-03-16 バガーマアトシュアピジ ボスカリス ベー．ファオ． Soil drainage system

Also Published As

Publication number Publication date
JP2006200204A (en) 2006-08-03

Similar Documents

Publication Publication Date Title
JP4032396B2 (en) Penetration structure and construction method thereof
JP4811668B2 (en) Osmotic structure
CN108442365B (en) Anti-blocking reinforced permeable pile and construction method
JP2007278008A (en) Improving method for soft ground
JP4609794B2 (en) Soft ground improvement method under permeable upper ground
JP4391664B2 (en) Ground improvement structure and construction method for soft ground
JP6426418B2 (en) Ground improvement method and ground improvement system
CN202787227U (en) Three-dimensional composite plastic water discharging body
WO2004040068A1 (en) Method and device for improving poor ground
JP2003055951A (en) Improving method and improving device for soft ground
JPH0529272Y2 (en)
JP2617129B2 (en) Construction method of underground infiltration equipment
CN211006700U (en) Foundation ditch flowing water lateral wall drainage protects structure
JP2006194044A (en) Installation method for water drain pipe in toe of slope on back of levee body, water draining method for seepage water on back of levee body, and water drain structure for seepage water
JP3002188B1 (en) Ground excavation method
JP2001164564A (en) Installation method of drain structure for impervious wall and wall joint section
KR20100074487A (en) Combining structure of drain board
JP2010084406A (en) Soft ground improving method, and soft ground improving construction apparatus for use in the method
JP2617128B2 (en) Construction method of underground infiltration equipment
JP4346078B2 (en) Ground improvement method
KR101577187B1 (en) Water and sewage pipelines to prevent subsidence structure
JP4033561B2 (en) Airtight structure in vacuum consolidation method
CN114837219B (en) Gravity type retaining wall structure of river channel and construction method thereof
JP7345165B2 (en) Non-overflow type infiltration system and its construction method
CN210194700U (en) Basement drainage anti-floating structure

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20071226

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20100317

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20100413

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20100914

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20101001

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20131022

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

Ref document number: 4609794

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313115

R360 Written notification for declining of transfer of rights

Free format text: JAPANESE INTERMEDIATE CODE: R360

R360 Written notification for declining of transfer of rights

Free format text: JAPANESE INTERMEDIATE CODE: R360

R371 Transfer withdrawn

Free format text: JAPANESE INTERMEDIATE CODE: R371

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313115

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250