JP3807894B2

JP3807894B2 - Curing method for solidified material treated soil and solidified material treated soil curing device

Info

Publication number: JP3807894B2
Application number: JP2000100781A
Authority: JP
Inventors: 哲朗山本; 茂生岡林; 秀利藤野
Original assignee: Mitsubishi Materials Corp; Ube Industries Ltd
Current assignee: Mitsubishi Materials Corp; Ube Corp
Priority date: 2000-04-03
Filing date: 2000-04-03
Publication date: 2006-08-09
Anticipated expiration: 2020-04-03
Also published as: JP2001279653A

Description

【０００１】
【発明の属する技術分野】
本発明は、固化材等を用いて化学的に安定化される土に対する圧密条件下における養生を可能にする養生装置、および、該装置を用いて固化処理効果測定用供試を得る養生方法に関するものである。より詳しくは、軟弱地盤に対し柱状改良、地中連壁、更には固化材添加土による盛土あるいは埋め戻しを行った際にしばしば起こる、処理土からの水の逃散をも含んだ圧密を、実験室で模擬的に再現するための養生装置の提供、及び、該装置を使用して、固化材による固化処理効果測定用供試体を作成する養生方法に関するものである。
尚、本明細書においては、固化材添加後の、固化が未だ十分進んでいない状態にある土を処理土と称し、固化材添加後、養生を受け、固化材の能力に応じた固化・安定化効果が発現した状態にある処理土を安定化処理土と称し、大まかに区別することにする。
【０００２】
【従来の技術】
軟弱な地盤や土質を安定化する方法の一つとして、セメント系、石灰系等の固化材を添加する化学的安定化工法が知られている。この工法においては、通常、予め改良対象地盤から採取したサンプル土に、土質試験室等で固化材の添加量を種々変えて混合した後、所定期間養生を加えて得られる安定化処理土を供試体とし、一軸圧縮試験によって一軸圧縮強さを求め、改良目標強度及び施工機械の混合性能等を考慮して、固化材添加量が決定されている。
この一軸圧縮試験では、一般に、処理土すなわち固化材が添加された処理対象土を直径５ｃｍ、高さ１０ｃｍの円筒形型枠に充填し、ランマー或いはタッピングによって締め固め、上面をフィルムで覆った後、静置状態で所定期間養生して得られる供試体について、一軸圧縮強度が測定される。すなわち、自重以外に外力が掛からず、且つ、どの面からも排水が起こらない条件下で作成された供試体について一軸圧縮強度が測定されることになる。
【０００３】
ところが、軟弱地盤の柱状改良、地中連壁、及び、処理土による盛土あるいは埋め戻しにおいては、固化材添加直後の所謂フレッシュ処理土は、その自重や上載荷重の作用によって、圧縮による高密度化すなわち圧密を受けている。この圧密によって、更には、それに伴う含水量低下によって、固化後の変形の程度あるいは強度特性は、圧密がない状態から大きく変化している筈であるから、安定化処理効果の評価は、圧密を受けた、更には、圧密時滲出水が除去された供試体について実施する方がより真実に近くより実用的な測定値が得られると考えられる。
【０００４】
土自体に対して圧密試験を行う方法は既に存在する。例えば、圧密方法については、土自体の圧密試験や三軸圧縮試験（ＣＵ、ＣＤ）で規格化されている。しかし、これ等はそれぞれ、土の圧密特性（圧縮特性）及び等方応力条件下における圧密後の剪断強度の測定を目的としているため、供試体作成には特殊な型枠を使用する必要が在り、また、装置自体の構造が複雑であることもあって、同時に製造・試験できる供試体数が制限されるのは不可避であった。
一方、固化材による安定化処理条件の把握には、条件を動かして作成された数多くの供試体についての試験が要求されることから、従来公知の圧密方法の適用は、作業効率、経済性の面で相応しいものではなく、更に、供試体寸法等、測定値精度に影響を及ぼす点においても改良を要するものであった。また、圧密時に生起する水逃散の影響も加味した供試体を与える装置の開発も望まれていた。
【０００５】
【発明が解決しようとする課題】
本発明は、固化材による安定化処理土の評価において、従来装置、方法が抱える上記問題点が解決された方法、装置の提供を目的とする。すなわち、固化材添加後の処理土に対する圧密を加えながらの養生、すなわち圧密養生が、処理土からの滲出水除去も含めて簡単に実施できる養生方法、およびそれを可能にする養生装置の開発を目的とする。
【０００６】
【課題を解決するための手段】
本発明者は、安定化処理土供試体作成に、従来も室内配合試験に通常使用されている円筒形型枠の使用が可能な、且つ、該型枠内に充填された処理土からの圧密時における滲出水除去が可能な構造としたことにより、上記方法を可能にする装置が得られることを見出し、本発明を完成した。すなわち、本発明は、固化処理効果測定用供試体を得る目的で、処理対象土に固化材を添加、混合して調整された処理土を養生するに際し、処理土を、室内配合試験用の円筒形型枠の下部及び該型枠の上部に設置されたカラー部の少なくとも一方が実質的に水のみを通す多孔板でシールされた状態となるように円筒形型枠上端面を超えてカラー部に充填した後、引続き、該養生期間中に処理土を充填した円筒形型枠の長手方向を上下に設置して上部から重錘により荷重を負荷し、且つ、荷重を負荷された処理土に由来する前記多孔板からの滲出水を、排水装置により系外に排出して行い、該供試体を脱型し、型枠上端面位置で平滑にして得られた供試体をそのまま一軸圧縮強さ試験に供することを特徴とする固化材処理土の養生方法に関する。また、本発明は、固化処理効果測定用供試体を得る目的で、処理対象土に固化材を添加、混合して調整された処理土に養生を加える養生装置であって、少なくとも一端が実質的に水のみを通す多孔板でシールされた円筒形型枠に充填されている処理土に対し長手方向を上下方向とし、載荷台および型枠上部に挿入された該載荷台の下降に連動し型枠及びカラー部内処理土へ荷重を伝達する伝達部より構成され、載荷台上に設置される錘量で型枠内処理土へ負荷する荷重量が調整可能な荷重負荷装置と、荷重を負荷された処理土に由来する前記多孔板からの滲出水を系外に排出する排水装置とから構成されていることを特徴とする固化材処理土養生装置に関する。以下に本発明を詳細に説明する。
【０００７】
【発明の実施の形態】
本発明の養生装置の主要部は、型枠、（上部及び／又は下部）多孔板、該多孔板位置に応じて設置される（上部及び／又は下部）排水管から構成される型枠部及び該型枠部に対する荷重負荷装置より構成される。図１に、本発明の養生装置の一例を示す。
供試体形成用型枠２の内径あるいは高さは特に限定されないが、内径／高さの比は１／２とするのが一般的である。特に、これと同じ内径／高さ比を有する、土質工学基準『安定処理土の締固めをしない供試体の作製方法ＪＳＦＴ８２１１９９０』に則って実施される固化材処理土の室内配合試験で使用されている円筒形型枠（径５ｃｍ×高さ１０ｃｍ又は径７．５ｃｍ×長さ１５ｃｍ）の使用は、測定精度は勿論のこと、入手の容易さ、コスト面から最も好ましい方法である。
【０００８】
本発明の装置を用いる圧密養生の第一ステップは、前記型枠への処理土の充填である。充填は、被処理土に所定量の固化材が添加、混合された直後の未だ固化していない状態にあるフレッシュ処理土を、底部に底板を設置した型枠２へ流し込んだ後、タッピング等の適当な方法で締め固めを行って空隙部を除去して行われる。
なお、処理土はその後の圧密工程で圧縮されて上面高さが当然変化するが、圧密養生後に得られる供試体高さが型枠高さに近くなるように、原土の土性、供試体への上載圧等を考慮して、処理土の充填量を調整するのが好ましい。
この場合、充填される処理土容量は、当然、型枠容量より大となるため、型枠上部にカラー３を設置し、圧密前の充填容量を確保する。
【０００９】
フレッシュ処理土充填後の型枠は、型枠底部から底板を取り外し、圧密装置上の加圧を受ける所定位置に設置された型枠内径と同径の下部多孔板４ｂ上に、ろ紙又はろ布を挟んで処理土下面が相対して位置する様に型枠を設置し、型枠上方から押圧部材７を挿入し、型枠の圧密装置への装着が完成する。
圧密を受けた際の、型枠に充填された処理土からの滲出水量の位置依存性は処理対象土の土性によって異なり、多孔板の設置は、処理土によっては上部又は下部だけでも十分な場合もあるが、一般的には、上下双方に多孔板を設置して、上下面双方からの除水を行うのが便利である。当然、排水設備は、どの場合にも対応出来る様、上下に設置されることになる。
上下多孔板は、圧密養生時に処理土から滲出する水を型枠外に排出するために設置されるものであるが、上部多孔板は、押圧部材と接しており、押圧部材からの荷重を処理土に伝達する機能も有することになる。
【００１０】
多孔板は、加わる荷重に耐えるものであれば種類を選ばず、十分な強度を有することが公知である、ポーラスストーン、ポーラスメタル更にはプラスチック製多孔板が使用できる。この場合、目の粗さが実質的に水のみを通す大きさの多孔板を用いれば、多孔板のみで処理土からの滲出水のみの系外への除去が可能である。目の粗い多孔板を使用する場合には、固体成分の逃散を防ぐためろ紙又はろ布と組合わせて使用することになるが、使用後多孔板の洗浄処理の必要性を考慮すれば、目の粗い多孔板をろ紙又はろ布、特に使い捨ての可能なろ紙と組合わせて使用するのが実用的には好ましい。ろ材も多孔板の一種であり、本発明においては、後者すなわち、多孔板をろ材と組合わせる場合についても”多孔板の使用”と定義することにする。
【００１１】
本発明の養生装置においては、圧密時に処理土から多孔板を経て滲出する水を、処理土の下面又は上下面に接して設置された排水溝・排水管を経由して系外へ除去することが可能な構造となっている。例えば、図１に示される装置では、養生装置底板を貫いて設置されている下部排水管８ｂの取水口直上に下部多孔板４ｂが設置され、上部多孔板４ａは、それと接して設置されている押圧部材７のほぼ中心部に上下方向に設けられた排水溝、それに連なり載荷台内部に水平方向に設けられた溝を経由して排水管８ａから系外に排水可能な構造となっている。排水溝及び排水管は、滲出水の系外への排除が可能であれば設定方法を選ばず、図１に示されたものに限定されないことは勿論である。
尚、排水管８ａ、８ｂ夫々にバルブを設けておけば、圧密時にそれを閉じることにより、必要に応じて非排水条件下で圧密養生することも可能である。
【００１２】
本発明の養生装置には、型枠内の処理土に荷重を加える設備が装着されている。加圧設備は、円筒形型枠内の処理土に対し可変的に加圧出来るものであれば何れも使用可能であるが、複数個の装置を並べて、複数個の試料を同時平行型で加圧するには、図１に示す錘を使用する方法が設備コストの面で最も好ましい方法である。この装置では、重錘６の荷重が、載荷台５更に押圧部材７を経て型枠内の処理土１に伝わる方式となっている。載荷台と押圧部材は一体である必要はない。
加える荷重は、柱状改良、盛土あるいは埋め戻し等の改良目的に応じて、安定化処理を受ける被処理土の湿潤密度、深度（高さ）、地下水位等の要因を勘案して決定する。この値は、２．０ｋｇ重／ｃｍ²まですなわち、型枠径が５ｃｍの場合、４０ｋｇ重までの荷重負荷が可能であれば十分である。
【００１３】
錘を荷重手段として使用する装置では、重錘と載荷台の質量の総量で設定値が決まることになるが、錘も、０．５、１、２、４、５、１０、１５、２０、３０ｋｇの９種を用意しておけば、この［載荷台＋８７．５ｋｇ］の範囲を０．５ｋｇ重刻みでカバーすることが可能であり、作業性の面から非常に便利である。
【００１４】
また、変位計９を装着することにより、型枠内処理土の容積変化を高さ変化として経時的に測定することが可能となる。変位計としては、ダイヤルゲージ又は電気式変位計が使用可能であるが、電気式変位計は、圧密養生時の容積変化の自動記録が必要な場合には非常に有用である。
【００１５】
圧密養生物が所定材齢に達した後は、直ちに脱型し、必要であれば供試体上端面を平滑にして一軸及び三軸圧縮試験を行い、変形・強度特性を測定し、固化材による安定化処理効果の評価を行う。
尚、圧密養生は、任意の時間単位で実施することができるが、単位時間当たりの圧密の程度は、安定材（固化材）の固化が進行すると共に大幅に減衰するため、圧密減衰が一定値に収斂した後には除荷しても構わない。
【００１６】
【実施例】
以下に、具体例を示し、本発明を更に詳しく説明するが、ここでは、含水比４８％の粘性土を処理対象土とした例を示す。
一般軟弱土用セメント系固化材（商品名：ユースタビラー１０）を、粘性土１ｍ³当たり６０ｋｇ添加し、５リットルのミキサーで５分間混練し、フレッシュ処理土を得た。このフレッシュ処理土を、底板上に設置された径５ｃｍ×高さ１０ｃｍの鋼鉄性円筒形型枠に充填し、タッピング法により締め固めを行った。
【００１７】
圧密養生は、図１に示す装置で行った。処理土の充填された型枠を底板ごと、養生装置台板上の所定位置に予めセットされている底部多孔板（ポーラスストーン）の直上に位置するように養生装置に移動した後、底板を除去し、処理土下面がろ紙を挟んで底部多孔板上に位置するように設置し、次いで、型枠内処理土上面にも、ろ紙を挟んで多孔板を設置した後、押圧部材をカラー内に挿入して、養生装置へのセットを終了した。
【００１８】
圧密養生は、載荷荷重（質量）を０（無載荷）、１０、２０、３０ｋｇと変化させて行ったが、圧密の進行程度については、変位計で処理土上面の高さ変化を連続的に測定してモニタリングした。尚、装置全体は、２０℃の恒温室に設置されている。
何れの荷重についても、圧密が収束したと見なせる圧密開始１００分後における圧密の程度を表１に示す。表１においては、圧密１００分後の処理土上面高さが、充填直後の処理土上面高さとの差で定義される沈下量として示されている。
【００１９】
次に、材齢７日間圧密養生したものについて、固化材による安定化処理における圧密の効果を調べた。０（無荷重）、１０kg、２０kg及び３０kg４種の荷重について各３本の供試体を作成し、その一軸圧縮強さを測定し、各荷重について３本の平均値を各荷重負荷時の測定値として、表１に合わせて示した。
【００２０】
【表１】

【００２１】
未だ固化の不十分な処理土に対して排水が可能な状態下で圧密を加えると、固化材の物理化学的作用に供試体の収縮が加わることから、収縮率（供試体上面の沈下率）は上載荷重と正の相関関係に在ること、及び、安定化処理後の、例えば材齢７日における一軸圧縮強さが大幅に増加することが予想されるが、表１に示された結果は、本発明の養生装置が、この二つの特性を再現する供試体を与えることを示している。
【００２２】
次に、上載荷重を３０ｋｇに固定し、供試体作成日を変えて繰り返し試験を行い、圧密処理による強度向上の再現性を調べた。結果を表２に示す。
発現強度は非常に良好に再現されている。
或る目的を達成するために設計された装置、方法が実用的であるためには、同一条件下で運転された場合には、同一と見なし得る物、結果を与えるものであることが不可欠であるが、表２の結果は、本発明の養生装置が、再現性に優れた供試体を与えることが分かる。
【００２３】
【表２】

【００２４】
【発明の効果】
本発明の養生装置は、荷重負荷、排水の効果を含んだ安定化処理土供試体を与える。供試体における安定化処理効果発現の再現性も良い。その上機構が簡単で、作業性、経済性にも優れている。本発明の養生装置を用いて作成された供試体を使用することにより、圧密の影響を含んだデータの入手が可能であり、該データを使えば、より現実に近い安定化処理条件の把握が可能となる。
【図面の簡単な説明】
【図１】本発明の養生装置の一例を示す図である。
【符号の説明】
１処理土
２型枠
３カラー
４ａ上部多孔板、
４ｂ下部多孔板
５載荷台
６重錘
７押圧部材
８ａ上部排水管
８ｂ下部排水管
９変位計[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a curing device that enables curing under a compaction condition for soil that is chemically stabilized using a solidifying material and the like, and a curing method for obtaining a test for measuring the effect of solidification treatment using the device. Is. More specifically, experiments were conducted on consolidation, including the escape of water from treated soil, which often occurs when soft ground is improved by columnar improvements, underground walls, and banking or backfilling with solidified material-added soil. The present invention relates to a curing apparatus for reproducing a simulation in a room and a curing method for creating a specimen for measuring a solidification effect by a solidifying material using the apparatus.
In this specification, the soil that has not yet sufficiently solidified after the addition of the solidifying material is referred to as treated soil, and after the solidifying material is added, the soil is cured and solidified and stabilized according to the capacity of the solidifying material. The treated soil in a state where the stabilization effect is expressed is referred to as stabilized treated soil, and is roughly distinguished.
[0002]
[Prior art]
As one of the methods for stabilizing soft ground and soil, a chemical stabilization method is known in which a solidifying material such as cement or lime is added. In this construction method, the stabilized soil obtained by adding curing to the sample soil collected from the ground to be improved in advance in various conditions in the soil test room, etc., and then curing for a predetermined period is provided. The uniaxial compression strength is obtained by a uniaxial compression test as a specimen, and the amount of solidification material added is determined in consideration of the improved target strength and the mixing performance of the construction machine.
In this uniaxial compression test, generally, treated soil, that is, treated soil to which a solidifying material is added, is filled into a cylindrical form having a diameter of 5 cm and a height of 10 cm, compacted by rammer or tapping, and the upper surface is covered with a film. The uniaxial compressive strength is measured for a specimen obtained by curing for a predetermined period in a stationary state. That is, the uniaxial compressive strength is measured for a specimen prepared under conditions where no external force other than its own weight is applied and drainage does not occur from any surface.
[0003]
However, in the improvement of columnar shape of soft ground, underground connection walls, and embankment or backfilling with treated soil, so-called freshly treated soil immediately after the addition of the solidifying material is densified by compression due to its own weight and the effect of overloading. In other words, it has been consolidated. Due to this compaction, and the accompanying decrease in water content, the degree of deformation or strength characteristics after solidification should have changed greatly from the state without compaction. Furthermore, it is considered that it is closer to the truth and a more practical measurement value can be obtained by performing the test on the specimen from which the exudate was removed during consolidation.
[0004]
There is already a method for performing a consolidation test on the soil itself. For example, the consolidation method is standardized by a consolidation test of soil itself or a triaxial compression test (CU, CD). However, these are intended to measure the compaction characteristics (compression characteristics) of soil and the shear strength after consolidation under isotropic stress conditions, respectively. Therefore, it is necessary to use a special formwork for specimen preparation. In addition, since the structure of the apparatus itself is complicated, it is inevitable that the number of specimens that can be simultaneously manufactured and tested is limited.
On the other hand, grasping the stabilization treatment conditions using the solidified material requires tests on a large number of specimens created by changing the conditions. Therefore, the application of the conventionally known consolidation method is effective in working efficiency and economy. It was not suitable in terms of the surface, and further improvements were required in terms of influencing the measurement accuracy, such as the size of the specimen. There has also been a demand for the development of a device that gives a specimen that takes into account the effect of water escape that occurs during consolidation.
[0005]
[Problems to be solved by the invention]
The object of the present invention is to provide a method and apparatus in which the above-mentioned problems of conventional apparatuses and methods are solved in the evaluation of the stabilized soil with a solidifying material. In other words, the development of a curing method that enables the curing while applying consolidation to the treated soil after the addition of the solidifying material, that is, consolidation curing, including exudate removal from the treated soil, and a curing device that enables it Objective.
[0006]
[Means for Solving the Problems]
The present inventor can use a cylindrical formwork that has been conventionally used for the indoor compounding test for the preparation of the stabilized treated soil specimen, and is compacted from the treated soil filled in the formwork. The present invention has been completed by finding that an apparatus capable of performing the above-described method can be obtained by adopting a structure capable of removing exudate water at the time. That is, in the present invention, when curing the treated soil prepared by adding and mixing the solidifying material to the soil to be treated for the purpose of obtaining a specimen for measuring the effect of solidifying treatment, the treated soil is converted into a cylinder for indoor blending test. The collar part beyond the upper end surface of the cylindrical formwork so that at least one of the lower part of the formwork and the collar part installed on the upper part of the formwork is substantially sealed with a porous plate that allows only water to pass through. Then, the longitudinal direction of the cylindrical formwork filled with the treated soil during the curing period is installed up and down to load with the weight from the upper part, and the loaded treated soil is loaded with the load. The exudate from the perforated plate is discharged out of the system by a drainage device, the specimen is demolded, and the specimen obtained by smoothing at the position of the upper end surface of the mold is directly uniaxial compressive strength. A method for curing solidified soil treated for testing In addition, the present invention is a curing apparatus for adding curing to a treated soil prepared by adding and mixing a solidifying material to a treated soil for the purpose of obtaining a specimen for measuring a solidified treatment effect, at least one end being substantially The longitudinal direction is the vertical direction with respect to the treated soil filled in the cylindrical mold frame sealed with a perforated plate that allows only water to pass through, and the mold is interlocked with the loading table and the lowering of the loading table inserted in the upper part of the mold frame. It consists of a transmission part that transmits the load to the frame and the treated soil in the collar part , and is capable of adjusting the amount of load applied to the treated soil in the mold by the amount of weight installed on the loading platform, and loads the load The present invention relates to a solidifying material treatment soil curing device characterized by comprising a drainage device for discharging exudate water from the perforated plate derived from the treated soil to the outside of the system. The present invention is described in detail below.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The main part of the curing device of the present invention includes a mold, a (upper and / or lower) perforated plate, a mold part composed of a drain pipe (upper and / or lower) installed according to the position of the perforated plate, and It is comprised from the load application apparatus with respect to this formwork part. In FIG. 1, an example of the curing apparatus of this invention is shown.
The inner diameter or height of the specimen forming mold 2 is not particularly limited, but the inner diameter / height ratio is generally ½. In particular, used in the indoor blending test of solidified soil treated in accordance with the geotechnical standard “Method for producing specimens without compaction of stabilized soil JSF T 82111990” having the same inside diameter / height ratio. The use of a cylindrical formwork (diameter 5 cm × height 10 cm or diameter 7.5 cm × length 15 cm) is the most preferable method in terms of measurement accuracy, availability, and cost.
[0008]
The first step of consolidation curing using the apparatus of the present invention is filling the mold with the treated soil. The filling is performed by pouring fresh treated soil that has not been solidified immediately after a predetermined amount of solidified material has been added and mixed into the treated soil into the mold 2 having a bottom plate at the bottom, and then tapping and the like. The gap is removed by compacting by an appropriate method.
The treated soil is compressed in the subsequent consolidation process, and the top surface height naturally changes. However, the soil properties of the raw soil and the specimen are adjusted so that the specimen height obtained after consolidation curing is close to the formwork height. It is preferable to adjust the filling amount of the treated soil in consideration of the overpressure on the surface.
In this case, the capacity of the treated soil to be filled is naturally larger than the capacity of the formwork, so that the collar 3 is installed on the upper part of the formwork to secure the filling capacity before consolidation.
[0009]
The mold after filling with the freshly treated soil is a filter paper or a filter cloth on the lower perforated plate 4b having the same diameter as the inner diameter of the mold placed at a predetermined position where the bottom plate is removed from the bottom of the mold and receiving pressure on the compacting device. The mold is set so that the lower surface of the treated soil is positioned relative to the mold, and the pressing member 7 is inserted from above the mold to complete the mounting of the mold on the compacting device.
The position dependency of the amount of exudation water from the treated soil filled in the mold when subjected to consolidation varies depending on the soil properties of the treated soil, and depending on the treated soil, only the upper part or the lower part may be installed. In some cases, however, it is generally convenient to install a porous plate on both the upper and lower sides to remove water from both the upper and lower surfaces. Naturally, drainage facilities will be installed one above the other so that they can be used in any case.
The upper and lower perforated plates are installed to discharge water that exudes from the treated soil during consolidation curing to the outside of the mold, but the upper perforated plate is in contact with the pressing member, and the load from the pressing member is treated with the treated soil. It also has a function of transmitting to
[0010]
The porous plate is not limited to any type as long as it can withstand the applied load, and a porous plate made of porous stone, porous metal or plastic, which is known to have sufficient strength, can be used. In this case, if a perforated plate having a mesh size that allows only water to pass through substantially is used, it is possible to remove only exuded water from the treated soil outside the system using only the perforated plate. When using a porous plate with a coarse mesh, it will be used in combination with filter paper or filter cloth to prevent the escape of solid components. It is practically preferable to use a rough perforated plate in combination with filter paper or filter cloth, particularly disposable filter paper. The filter medium is also a kind of perforated plate. In the present invention, the latter case, that is, the case where the perforated plate is combined with the filter medium is defined as “use of perforated plate”.
[0011]
In the curing device of the present invention, water exuded from the treated soil through the perforated plate at the time of compaction is removed outside the system via drainage grooves and drainage pipes installed in contact with the lower surface or upper and lower surfaces of the treated soil. Is a possible structure. For example, in the apparatus shown in FIG. 1, the lower porous plate 4b is installed immediately above the intake port of the lower drainage pipe 8b installed through the bottom plate of the curing device, and the upper porous plate 4a is installed in contact therewith. It has a structure that allows drainage from the drainage pipe 8a to the outside of the system via a drainage groove provided in the vertical direction substantially at the center of the pressing member 7 and a groove provided in the horizontal direction inside the loading platform. Of course, the drainage grooves and drainage pipes are not limited to those shown in FIG. 1, as long as the exudate can be excluded from the system.
If a valve is provided in each of the drain pipes 8a and 8b, it is possible to perform consolidation curing under non-drainage conditions as necessary by closing it during consolidation.
[0012]
The curing device of the present invention is equipped with equipment for applying a load to the treated soil in the mold. Any pressurization equipment can be used as long as it can variably pressurize the treated soil in the cylindrical formwork, but a plurality of devices are arranged side by side, and a plurality of samples are added in parallel at the same time. In order to press, the method using the weight shown in FIG. 1 is the most preferable method in terms of equipment cost. In this apparatus, the load of the weight 6 is transmitted to the processing soil 1 in the formwork through the loading table 5 and the pressing member 7. The loading table and the pressing member need not be integral.
The load to be applied is determined in consideration of factors such as the wet density, depth (height), groundwater level, etc. of the soil to be treated according to the purpose of improvement such as columnar improvement, embankment or backfilling. This value is sufficient up to 2.0 kg weight / cm ² , that is, when a load of up to 40 kg weight is possible when the formwork diameter is 5 cm.
[0013]
In an apparatus that uses a weight as a loading means, the set value is determined by the total mass of the weight and the loading platform, but the weight is also 0.5, 1, 2, 4, 5, 10, 15, 20, If nine types of 30 kg are prepared, it is possible to cover this [loading table + 87.5 kg] range with 0.5 kg increments, which is very convenient from the viewpoint of workability.
[0014]
In addition, by mounting the displacement meter 9, it is possible to measure the volume change of the treated soil in the mold as a height change over time. As the displacement meter, a dial gauge or an electrical displacement meter can be used. However, the electrical displacement meter is very useful when it is necessary to automatically record a volume change during consolidation curing.
[0015]
Immediately after the compacted organism has reached the specified age, it is removed from the mold, and if necessary, the upper end surface of the specimen is smoothed and uniaxial and triaxial compression tests are performed to measure deformation and strength characteristics. Evaluate the stabilization effect.
Consolidation curing can be carried out in arbitrary time units, but the degree of consolidation per unit time is greatly attenuated as the stabilization of the stabilizing material (solidified material) proceeds, so the consolidation attenuation is a constant value. You can unload it after it converges.
[0016]
【Example】
Hereinafter, the present invention will be described in more detail with reference to specific examples. Here, an example in which viscous soil having a water content ratio of 48% is used as the treatment target soil is shown.
Cement-based solidifying material for general soft soil (trade name: Youth Tabira 10) was added in an amount of 60 kg per 1 m ^{3 of} clay soil, and kneaded for 5 minutes with a 5 liter mixer to obtain freshly treated soil. This freshly treated soil was filled in a steel cylindrical mold having a diameter of 5 cm and a height of 10 cm installed on the bottom plate, and compacted by a tapping method.
[0017]
Consolidation curing was performed with the apparatus shown in FIG. After moving the formwork filled with treated soil to the curing device so that the bottom plate and the bottom porous plate (porous stone) set in advance at a predetermined position on the curing device base plate are moved to the curing device, the bottom plate is removed The bottom surface of the treated soil is placed on the bottom perforated plate with the filter paper in between, and then the porous plate is placed on the top surface of the treated soil in the mold with the filter paper in between, and then the pressing member is placed in the collar. Inserted and finished setting to the curing device.
[0018]
Consolidation curing was performed by changing the loading load (mass) to 0 (no loading), 10, 20, and 30 kg. However, the degree of consolidation progressed was continuously measured with a displacement meter. Measured and monitored. The entire device is installed in a constant temperature room at 20 ° C.
Table 1 shows the degree of consolidation 100 minutes after the start of consolidation for which any load can be regarded as convergence. In Table 1, the height of the treated soil upper surface after 100 minutes of consolidation is shown as the amount of settlement defined by the difference from the height of the treated soil upper surface immediately after filling.
[0019]
Next, the effect of the consolidation in the stabilization treatment with the solidified material was examined for those that were consolidated and cured for 7 days. Three test specimens were prepared for each of four loads of 0 (no load), 10 kg, 20 kg, and 30 kg, the uniaxial compressive strength was measured, and the average value of the three specimens was measured for each load. As shown in Table 1.
[0020]
[Table 1]

[0021]
When compaction is applied to the treated soil that is still insufficiently solidified in a state where drainage is possible, the shrinkage of the specimen will be added to the physicochemical action of the solidified material (the settlement ratio of the top surface of the specimen). Is positively correlated with the loading load, and the uniaxial compressive strength after stabilization treatment, for example, at 7 days of age, is expected to increase significantly. The results shown in Table 1 Indicates that the curing device of the present invention provides a specimen that reproduces these two characteristics.
[0022]
Next, the upper load was fixed at 30 kg, and the test was repeated while changing the specimen preparation date, and the reproducibility of the strength improvement by the consolidation treatment was examined. The results are shown in Table 2.
The expression intensity is reproduced very well.
In order for a device or method designed to achieve a certain purpose to be practical, it is indispensable to provide what can be regarded as the same and result when operated under the same conditions. However, the results in Table 2 show that the curing device of the present invention gives a specimen having excellent reproducibility.
[0023]
[Table 2]

[0024]
【The invention's effect】
The curing device of the present invention provides a stabilized soil sample including the effects of load loading and drainage. The reproducibility of the stabilization treatment effect expression in the specimen is also good. In addition, the mechanism is simple, and it is excellent in workability and economy. By using a specimen prepared using the curing apparatus of the present invention, it is possible to obtain data including the influence of consolidation, and by using this data, it is possible to grasp stabilization processing conditions that are more realistic. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a curing device of the present invention.
[Explanation of symbols]
1 treated soil 2 formwork 3 collar 4a upper perforated plate,
4b Lower perforated plate 5 Loading platform 6 Weight 7 Press member 8a Upper drain pipe 8b Lower drain pipe 9 Displacement meter

Claims

For the purpose of obtaining a specimen for measuring the effect of solidification treatment, when curing the treated soil prepared by adding and mixing the solidification material to the treated soil, the treated soil is placed at the bottom of the cylindrical formwork for indoor blending tests. After filling the collar part beyond the upper end surface of the cylindrical formwork so that at least one of the collar parts installed at the upper part of the mold form is sealed with a perforated plate that substantially allows only water to pass, From the perforated plate derived from the treated soil loaded with the load, the longitudinal direction of the cylindrical mold filled with the treated soil during the curing period is set up and down and a load is applied by a weight from above. The exuded water is discharged out of the system by a drainage device, the specimen is demolded, and the specimen obtained by smoothing at the upper end surface position of the mold is directly subjected to a uniaxial compressive strength test. Curing method for solidified material treated soil.

A curing device that adds curing material to the soil to be treated and mixes it to the treated soil for the purpose of obtaining a specimen for measuring the effect of solidification treatment. At least one end of the device is substantially porous. With respect to the processing soil filled in the cylindrical formwork sealed with a plate, the longitudinal direction is the vertical direction, and the formwork and the collar part are interlocked with the descending of the loading table and the loading table inserted into the upper part of the moldwork. It consists of a transmission part that transmits the load to the inner treated soil, and the load load device that can adjust the load applied to the treated soil in the mold by the weight installed on the loading platform, and the treated soil loaded with the load A solidifying material treatment soil curing device, characterized in that it is composed of a discharge device for discharging exudate from the perforated plate originating from the outside of the system.