JPH06136738A - Ground freezing construction method - Google Patents
Ground freezing construction methodInfo
- Publication number
- JPH06136738A JPH06136738A JP30756992A JP30756992A JPH06136738A JP H06136738 A JPH06136738 A JP H06136738A JP 30756992 A JP30756992 A JP 30756992A JP 30756992 A JP30756992 A JP 30756992A JP H06136738 A JPH06136738 A JP H06136738A
- Authority
- JP
- Japan
- Prior art keywords
- brine
- ground
- cooling
- freezing
- excavation
- 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.)
- Pending
Links
Landscapes
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、地下の建設工事に先行
して、高水位の軟弱地盤或いは地下での湧水を凍結させ
ることにより地盤を強固にする地盤の凍結工事方法に係
り、地表面下の掘削空間に注入した高熱伝導率の流動体
を介して、広面積の冷却体により上記掘削空間の全域を
含む地盤壁部に亙って効率的且つ短期間に凍結せしめ得
る地盤凍結工事方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground freezing construction method for strengthening the ground by freezing high-level soft ground or underground spring water prior to underground construction work. Ground freezing work that can be frozen efficiently and in a short period of time over a ground wall including the entire area of the above-mentioned excavation space with a large-area cooling body through a fluid with high thermal conductivity injected into the excavation space below the surface. Regarding the method.
【０００２】[0002]
【従来の技術】従来、地下工事の補助的工法の一つとし
て地盤凍結工法があるが、これは地下水位の高い軟弱な
地盤或いは地中の湧水を凍結させて、地盤を強固にする
ことによって掘削をし易くする目的で施行されている。
図５に示すように凍結予定地点に例えば約８００ｍｍ間
隔でボーリングして棒状冷却管１２を地中に埋設し、こ
の冷却管に地上の冷凍装置から冷熱エネルギを供給し
て、前記冷却管の周囲の土壌を点状に凍結させて凍土１
５を形成している。（第１の従来技術という）2. Description of the Related Art Conventionally, there is a ground freezing method as one of the auxiliary construction methods for underground construction. This is to freeze the soft ground with a high groundwater level or the spring water in the ground to strengthen the ground. Has been implemented for the purpose of facilitating excavation.
As shown in FIG. 5, a rod-shaped cooling pipe 12 is buried in the ground by boring at a freezing point, for example, at intervals of about 800 mm, and cooling energy is supplied to the cooling pipe from a refrigeration unit on the ground to surround the cooling pipe. Frozen soil 1
5 is formed. (Referred to as the first conventional technology)
【０００３】又、例えば、地表から適宜の深さに亙って
未凍結土を残し、その周囲を凍結した後、前記未凍結土
を掘削してそこに構築物を建設する場合には、前記凍結
させない部分に相当する冷却用外管の上部内側に断熱材
の充填部を設けて、前記外管との間を冷媒が通過できる
ようにした内管を挿入してなる３重式凍結管（冷却管）
を用い、前記第１の従来技術と同様に該冷却管を地中に
埋設し、冷凍装置から前記内管の冷媒送給孔を介して送
り込まれる冷媒が、前記内管内を通って下部内管に入
り、この下部内管と前記外管との間を通って上昇し、更
に前記内管と前記外管との間を通って外部へ排出すると
いった操作を連続的に繰り返すことによって、前記外管
の断熱材充填部を設けていない部分の外周に凍土を形成
し、前記断熱材充填部の外周は、断熱によって冷媒によ
る冷却が阻止されて凍結しないまま残されるという凍結
方法が知られている。（第２の従来技術という）Further, for example, when unfrozen soil is left at an appropriate depth from the surface of the earth and the surrounding area is frozen, and then the unfrozen soil is excavated to construct a structure there, the frozen A triple freezing tube (cooling) in which a filling portion of a heat insulating material is provided inside the upper portion of a cooling outer tube corresponding to a portion which is not allowed to be inserted, and an inner tube through which a refrigerant can pass between the outer tube is inserted tube)
In the same manner as in the first conventional technique, the cooling pipe is buried in the ground, and the refrigerant fed from the refrigerating device through the refrigerant feeding hole of the inner pipe passes through the inner pipe to form the lower inner pipe. The lower inner pipe and the outer pipe to rise, and then discharge between the inner pipe and the outer pipe to the outside. A freezing method is known in which frozen soil is formed on the outer circumference of a portion of the pipe where the heat insulating material filling portion is not provided, and the outer circumference of the heat insulating material filling portion is left unfrozen because cooling by a refrigerant is blocked by heat insulation. . (Referred to as second conventional technology)
【０００４】また、地中に鋼矢板を打込んで土止め作業
途中に、該鋼矢板と直角に埋設された水道管や下水管、
或いは通信ケーブル等が工事の障害となる場合には、前
記鋼矢板の打込み不能箇所に生じる隙間を塞ぐため、こ
の部分の凍結が行なわれる。この場合、随意の長さの横
断面がＬ字状の固結材、例えばコンクリートによる板体
内に、屈折蛇行した冷却管を挿通して冷却板体とし、こ
れを前記鋼矢板と直角な埋設物とに沿うように埋設し、
冷凍装置から冷熱エネルギを供給して前記冷却板体を凍
結させることにより、障害物と鋼矢板とにより生じる隙
間のある地盤を凍結させる方法がある。（第３の従来技
術という）[0004] Further, a water pipe or a sewer pipe which is buried at a right angle to the steel sheet pile, while driving the steel sheet pile into the ground to stop the earth.
Alternatively, when the communication cable or the like interferes with the construction, this portion is frozen in order to close the gap formed at the non-implantable portion of the steel sheet pile. In this case, a refrigerating meandering cooling tube is inserted into a plate made of an L-shaped solid material having a cross section of an arbitrary length, for example, concrete, to form a cooling plate, which is embedded at right angles to the steel sheet pile. Buried along with,
There is a method of freezing the ground having a gap generated by an obstacle and a steel sheet pile by supplying cold energy from a refrigerating device to freeze the cooling plate body. (Referred to as third conventional technology)
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、前記従
来の第１技術、第２技術はともに、棒状冷却管により点
状の限られた周囲を凍結させることはできるが、広範囲
に亙って面状に凍結させるためには前記冷却管の埋設数
を増加させなくてはならず、しかも凍結部までの深さに
よって何本かの冷却管を溶接等により継足して長くする
必要があり、凍結範囲が点状に限られ而も凍結速度が遅
いだけでなく、冷却管の設置工数と工費が嵩むといった
欠点がある。However, in both the above-mentioned first and second conventional techniques, it is possible to freeze a point-shaped limited periphery by a rod-shaped cooling pipe, but it is possible to cover a wide area with a planar shape. In order to freeze it, it is necessary to increase the number of buried cooling pipes, and it is necessary to lengthen some cooling pipes by welding etc. depending on the depth to the freezing part. However, it is limited to dots, and not only the freezing speed is slow, but also the number of man-hours for installing the cooling pipe and the cost increase.
【０００６】更に前記第３の従来技術による冷却板体を
用いる凍結方法では、冷却管を挿通した前記冷却板体が
コンクリート製のために断熱作用によって凍結を阻害す
るといった障害があり、この凍結方法も凍結速度が遅い
ばかりか余分な冷熱エネルギを消費し、工期が長くなる
という障害がある。Further, in the freezing method using the cooling plate body according to the third prior art, since the cooling plate body having the cooling pipe inserted therein is made of concrete, there is a drawback that the freezing is inhibited by a heat insulation effect. In addition, the freezing speed is slow, and extra cooling energy is consumed, resulting in a longer construction period.
【０００７】本発明の目的は、従来技術の欠点に鑑み、
土質条件の相違による凍結効果と平板冷却体の優位性に
着目し、凍結工事の施工地盤への凍結用冷却体の埋設、
冷凍装置の設置が容易で、地盤の凍結が広範囲且つ短期
間に行ない得る経済的で、安全且つ効率的な地盤凍結工
事の施工方法を提供することにある。The object of the present invention is, in view of the drawbacks of the prior art,
Focusing on the freezing effect due to the difference in soil conditions and the superiority of the flat plate cooling body, embedding the cooling body for freezing in the construction ground of the freezing work,
It is an object of the present invention to provide an economical, safe and efficient construction method for ground freezing work in which a refrigeration system can be easily installed, and the ground can be frozen over a wide area in a short period of time.
【０００８】[0008]
【課題を解決するための手段】本発明は、掘削予定地点
の地表面下をパイロット削孔し、続いてスリット掘削に
より所要の空間を設け、この地下空間に冷却体を投入す
るとともに、周囲の地盤土質の飽水度よりも高熱伝導率
で高比重の流動体例えば鉄粉等の金属粉を含む汚泥を注
入充填して、冷却体と流動体との熱伝導を良好ならし
め、前記冷却体に対して冷凍装置から冷熱エネルギを給
送することにより、前記流動体を介して前記冷却体から
地盤壁部に至る一帯を広範囲に亙って急速に凍結するこ
とを特徴とするものである。According to the present invention, a pilot hole is drilled under the ground surface at a planned excavation point, and then a required space is provided by slit excavation. A fluid of higher specific gravity and higher thermal conductivity than the soil water saturation, for example, sludge containing metal powder such as iron powder is injected and filled to make the heat conduction between the cooling body and the fluid good, On the other hand, by supplying cold energy from a refrigerating device, a zone from the cooling body to the ground wall portion is rapidly frozen over a wide range through the fluid.
【０００９】又、本発明は、好ましくは前記掘削により
設けられた地下空間に投入すべき冷却体は、金属製タン
ク内で平面状に鋼管を並列に並べて両端を共通管に連結
して冷熱エネルギを給送するようにした平板タンク型、
又は１本の鋼製給送管を平面状に屈折蛇行させたヘアピ
ンコイル型、或いは２組のＬ字状鋼製給送管を平面状に
並べて夫々の１辺を複数の分岐管を介して相互に連結し
たアイスパネル型等、平面状に形成すればよい。Further, according to the present invention, preferably, the cooling body to be put into the underground space provided by the excavation is such that the steel pipes are arranged in parallel in a plane in a metal tank and both ends thereof are connected to a common pipe to cool and cool energy. Flat tank type,
Or, a hairpin coil type in which one steel feed pipe is bent and meandered in a plane, or two sets of L-shaped steel feed pipes are arranged in a plane and one side of each is provided with a plurality of branch pipes. It may be formed in a flat shape such as an ice panel type connected to each other.
【００１０】そしてまた本発明は、好ましくは前記冷凍
装置に、ブライン方式又は液化ガス方式の冷凍装置から
冷熱エネルギを給送可能にすればよい。Further, according to the present invention, it is preferable that cold energy can be supplied to the refrigerating apparatus from a brine type or liquefied gas type refrigerating apparatus.
【００１１】[0011]
【作用】従ってかかる技術手段によれば、掘削地盤の性
状如何を問わず、掘削した地下空間に充填した流動体が
周囲の地盤の飽水土の熱的性質よりも高熱伝導率を有し
ているので、上記流動体が板状冷却体の周囲から地盤の
壁部に亘る広い区域に冷却エネルギが効率的且つ急速に
伝えられて凍結を助長せしめることができる。Therefore, according to such a technical means, the fluid filled in the excavated underground space has a higher thermal conductivity than the thermal properties of the saturated soil in the surrounding ground regardless of the properties of the excavated ground. Therefore, the fluid can efficiently and rapidly transfer the cooling energy to a wide area extending from the periphery of the plate-shaped cooling body to the wall portion of the ground to promote freezing.
【００１２】又、掘削空間に埋設される板状冷却体は、
埋設精度を問題にすることがないので、その設置に手間
取らず、広い面積に亙って高熱伝導率の流動体と接触し
て、高速に凍結範囲を拡げることができる。The plate-shaped cooling body embedded in the excavation space is
Since the burying accuracy does not pose a problem, it is possible to expand the freezing range at high speed by contacting with a fluid having a high thermal conductivity over a wide area without taking time and effort for the installation.
【００１３】更にエチレングリコール等のブラインを冷
却媒体とするブライン方式の冷却装置では、冷凍能力の
蓄積ができるために急激な温度上昇を避けることがで
き、又、液化ガス方式の冷却装置は、凍結現場への液化
ガスの搬入にタンクローリー車をそのまま横付けして作
業を開始できる簡便さが有利となる。Further, in a brine type cooling device using brine such as ethylene glycol as a cooling medium, a rapid temperature rise can be avoided because the refrigerating capacity can be accumulated, and a liquefied gas type cooling device can freeze. It is advantageous that the tank truck truck can be installed as it is to carry the liquefied gas to the site and the operation can be started.
【００１４】[0014]
【実施例】以下、図面を参照して本発明の好適な実施例
を例示的に詳しく説明する。ただし、この実施例に記載
されている構成部品の寸法、材質、形状、その相対配置
などは、特に特定的な記載がない限りは、この発明の範
囲をそれのみに限定する趣旨はなく、単なる説明例に過
ぎない。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless otherwise specified, and are simply It is only an example.
【００１５】先ず本発明の実施例に係る地盤凍結工事方
法を説明するに先立ち、システムについて図１により述
べるに、図１（Ａ）、（Ｂ）は夫々異なる実施例ではあ
るが両者ともに地表面下の掘削空間に土壌を凍結させる
ための冷却体１１−１、１１−２又は１１と、上記冷却
体を介して凍結能力を助長する流動体１６とが投入さ
れ、上記冷却体に冷熱エネルギを給送する冷凍装置Ｒを
備えている。First, before explaining the ground freezing construction method according to the embodiment of the present invention, the system will be described with reference to FIG. 1. Although FIGS. 1 (A) and 1 (B) are different embodiments, both of them are ground surfaces. Cooling bodies 11-1, 11-2 or 11 for freezing soil and a fluid body 16 for promoting freezing ability are introduced into the lower excavation space through the cooling bodies to supply cooling energy to the cooling bodies. A refrigerating device R for feeding is provided.
【００１６】そして凍結すべき対象地盤の熱的性質とし
ては、凍結速度、凍結負荷、温度分布、解凍速度等が関
係する熱伝導方程式を解くことによっても求められる
が、平板に対する１次元理論と単管に対する２次元理論
とから、凍結工事の施工上、平板冷却体による凍結速度
が単管冷却に比べて速く、実験結果ともよく合致するこ
とが判っている。The thermal properties of the target ground to be frozen can also be obtained by solving a heat conduction equation related to freezing speed, freezing load, temperature distribution, thawing speed, etc. From the two-dimensional theory for pipes, it has been found that the freezing rate by the flat plate cooling body is faster than that of the single pipe cooling in the construction of freezing work, and agrees well with the experimental results.
【００１７】そこで本発明の実施に用いられる冷却体１
１について図２により説明するに、図２（Ａ）は平板凍
結に最も近似させるに相応しい平板タンク型で、内部を
空洞状に形成しても、又、必要に応じてタンク１２０内
にブラインを充填した状態で、冷熱エネルギを給送する
鋼管を金属製タンク１２０内で、例えば並列に並べて両
端を共通管１１０に連結してもよい。同図（Ｂ）は１本
の鋼管を平面状に沿って多回屈折部１１１をもって蛇行
させて構成したヘアピンコイル型、同図（Ｃ）はＬ字状
の鋼管１１２を２組、夫々の１辺を複数の分岐管１１３
を介して互いに連結して実質的に平面状に構成したアイ
スパネル型を示し、これらは理想的な平板凍結を目的と
して構成されており、重量、価格、凍結後の取扱易さ等
を総合的に勘案して何れかの型を選択することができ
る。Therefore, the cooling body 1 used for implementing the present invention.
2 will be described with reference to FIG. 2. FIG. 2 (A) shows a flat plate tank type that is most approximate to flat plate freezing. Even if the inside is formed in a hollow shape, brine is also stored in the tank 120 if necessary. In the filled state, steel pipes for supplying cold energy may be arranged in parallel in the metal tank 120, for example, and both ends may be connected to the common pipe 110. FIG. 1B shows a hairpin coil type structure in which one steel pipe is meandered along a plane with multiple bending portions 111, and FIG. 1C shows two sets of L-shaped steel pipes 112, one for each Sides with multiple branch pipes 113
It shows an ice panel type that is connected to each other via a to form a substantially flat surface, and these are configured for the purpose of ideal freezing of the flat plate, and the weight, price, ease of handling after freezing, etc. are comprehensive. Either type can be selected in consideration of the above.
【００１８】次に、前記掘削空間に注入充填される流動
体としては、土壌の地中温度を例えば＋１８℃、容積含
水率０．６ｍ3 ／ｍを基準とした時に、土壌の凍結の
前、後で比熱（Ｋｃａｌ／ｍｈ℃）が１．２２５４、
２．３１３７、温度伝播率（ｍ2／ｈ）が１．４４７８
×１０-3、４．５２８８×１０-2を一応の目安とし、掘
削地点の土壌が有する熱伝導度に基いて汚泥を選択すれ
ばよく、例えば、上記汚泥中に鉄粉等の金属粉を混入す
ることによって熱伝導率を向上させることができる。Next, as the fluid to be injected and filled into the excavation space, when the ground temperature of the soil is, for example, + 18 ° C. and the volumetric water content is 0.6 m 3 / m, before the freezing of the soil, Later the specific heat (Kcal / mh ° C) was 1.2254,
2.3137, temperature transfer coefficient (m 2 / h) is 1.4478
The sludge may be selected based on the thermal conductivity of the soil at the excavation point, for example, 10 × 3 −4.5288 × 10 −2, and for example, metal powder such as iron powder may be added to the sludge. By mixing, the thermal conductivity can be improved.
【００１９】更に又、前記冷却体に給送すべき冷熱エネ
ルギについては前記の条件下で凍結潛熱（Ｋｃａｌ／Ｋ
ｇ）が２８．９２７であることに注目し、前記掘削空間
に投入された前記板状冷却体１１−１、１１−２、又は
１１に対する冷熱エネルギの供給源となる冷凍装置Ｒの
冷熱容量を求めることができ、代表的には図１（Ａ）の
ブライン方式、又は同図（Ｂ）の液化ガス方式を選択し
て採用することができる。図１（Ａ）において冷却媒体
としてのブラインは、ブラインクーラ１において冷媒側
より熱を交換されて冷やされ、循環ポンプ６によって冷
却体１１−１、１１−２へパイプラインＰ1及びＰ2を介
して給送され、再度該ブラインクーラ１へ戻されるブラ
インサイクル（点線にて示す）と、上記吸収された熱の
ために冷媒が蒸発して圧縮機２に吸入され、所定の圧力
まで凝縮した後、この高圧ガスを凝縮器３に送って奪熱
して液化し、該凝縮液を膨張弁を介して上記ブラインク
ーラへ送り込まれ、ここで前記ブラインと蒸発の潜熱が
熱交換され、上記ブラインを冷却した後、再度圧縮機に
戻入し、前記サイクルを繰り返す冷媒サイクル（実線で
示す）と、冷却水が吸収した熱を循環ポンプ４によって
冷却塔５へ送られ、外部に放出する冷却サイクル（１点
鎖線で示す）とから構成されている。又、同図（Ｂ）に
示す液化ガス方式による冷凍装置Ｒは、タンクローリ車
２１に加圧して詰込まれている例えば液体窒素を、貯槽
２２及び膨張弁２３を介して、冷却体１１へ給送循環さ
せ、気化ガスとして大気に放出されるものである。Further, the cold heat energy to be fed to the cooling body is subject to freezing heat (Kcal / K) under the above conditions.
Note that g) is 28.927, and the cold heat capacity of the refrigerating apparatus R, which is a supply source of cold heat energy to the plate-shaped cooling bodies 11-1, 11-2, or 11 thrown into the excavation space, It can be determined, and typically, the brine system of FIG. 1A or the liquefied gas system of FIG. 1B can be selected and adopted. In FIG. 1A, the brine as a cooling medium is cooled by exchanging heat from the refrigerant side in the brine cooler 1 and cooled by the circulation pump 6 to the cooling bodies 11-1 and 11-2 through the pipelines P 1 and P 2 . A brine cycle (shown by a dotted line) in which the refrigerant is fed through the compressor and returned to the brine cooler 1 again, the refrigerant is evaporated due to the absorbed heat and is sucked into the compressor 2 and condensed to a predetermined pressure. After that, the high-pressure gas is sent to the condenser 3 to remove heat and liquefy, and the condensate is sent to the brine cooler through an expansion valve, where the brine and latent heat of evaporation are heat-exchanged, and the brine is removed. After cooling, it is returned to the compressor again and the refrigerant cycle (shown by the solid line) in which the above cycle is repeated, and the heat absorbed by the cooling water is sent to the cooling tower 5 by the circulation pump 4 and released to the outside. It is composed of a clou (shown by a one-dot chain line). Further, the refrigerating apparatus R by the liquefied gas system shown in FIG. 1B supplies, for example, liquid nitrogen pressurized and packed in the tank truck 21 to the cooling body 11 via the storage tank 22 and the expansion valve 23. It is circulated and released as vaporized gas into the atmosphere.
【００２０】しかして前記したような本発明の地盤凍結
に不可欠な各手段並びに掘削性能に優れる油圧モータ駆
動式スリット掘削機（図６）を用いて本発明の地盤凍結
工事方法について、図３の施工順序に従って説明する。
先ず図３（Ａ）において凍結対象の未凍土１４の地表面
に、図６（Ｂ）に２点鎖線で示すようなチエーンソー６
３が折畳まれた状態の掘削機を設置して、例えばピット
外形が例えば約３５０ｍｍのパイロット孔を試掘し、こ
の孔底で上記掘削機のチエンソー６３を実線矢示のよう
に開角させて土壌壁を削除しつつ点線矢示の開孔端へ向
って引張り上げていくことによって、３図（Ｂ）のよう
な例えば約２，０００ｍｍ×７５ｍｍのスリット状の地
下空間１０が掘削され、ここで上記掘削機が撤去され
る。そして続いて３図（Ｃ）のように、パイプラインＰ
より冷熱エネルギが給送される例えば厚み５０ｍｍ、縦
２，０００ｍｍ、横１，０００の板状冷却体１１を、先
に掘削された上記地下空間１０内に投入して地上からハ
ンガＨ等により吊り下げるとともに、その土壌の掘削壁
部１３の飽水土がもつ熱的性質の基礎データに徹して、
例えば鉄粉等の金属粉を混入した高熱伝導率をもった汚
泥を流動体１６として注入充填する。ここに、上記掘削
される地下空間１０は本実施例の如くスリット状をはじ
め、立方状に掘削形成しても構わない。As a result, the ground freezing construction method of the present invention using the respective means indispensable for the ground freezing of the present invention as described above and the hydraulic motor driven slit excavator having excellent excavation performance (FIG. 6) will be described with reference to FIG. It will be explained according to the construction order.
First, on the ground surface of the unfrozen soil 14 to be frozen in FIG. 3 (A), a chain saw 6 as shown by a two-dot chain line in FIG. 6 (B).
Install the excavator in the state where 3 is folded, for example, test-drill a pilot hole with a pit outer shape of, for example, about 350 mm, and open the chain saw 63 of the excavator at the bottom of the hole as shown by the solid line arrow. By removing the soil wall and pulling it toward the open end indicated by the dotted arrow, a slit-like underground space 10 of, for example, about 2,000 mm × 75 mm as shown in FIG. 3B is excavated. The above excavator is removed at. Then, as shown in FIG. 3C, the pipeline P
For example, a plate-shaped cooling body 11 having a thickness of 50 mm, a length of 2,000 mm, and a width of 1,000, to which cold energy is fed, is put into the previously excavated underground space 10 and suspended from the ground by a hanger H or the like. As well as lowering it, sticking to the basic data of the thermal properties of the saturated soil of the excavation wall 13 of that soil,
For example, sludge having a high thermal conductivity mixed with metal powder such as iron powder is injected and filled as the fluid 16. Here, the underground space 10 to be excavated may be formed in a cubic shape as well as a slit shape as in the present embodiment.
【００２１】そして次に、前記図３（Ｃ）の地点へ前記
図１に示した冷凍装置Ｒを配設して、投入されている前
記冷却体１１に 配管を通して冷熱エネルギを給送循環
させると、冷却体が全面的に冷却されるに伴って、注入
充填された高熱導電率の汚泥が高効率で冷却されて、掘
削壁部１３への熱伝導作用を助長し、上記冷却体１１の
周辺全体から流動体１６である汚泥を介し掘削壁部１３
の全域に亙って急速に全面凍結するに至るのである。Next, when the refrigerating apparatus R shown in FIG. 1 is arranged at the point of FIG. 3 (C) and the cooling energy is fed and circulated through the pipe to the cooling body 11 being put in. As the cooling body is entirely cooled, the injected and filled sludge having a high thermal conductivity is cooled with high efficiency to promote the heat conduction action to the excavation wall portion 13, and the periphery of the cooling body 11. The whole excavation wall 13 through the sludge that is the fluid 16
It rapidly freezes all over the area.
【００２２】次に本発明の地盤凍結工事方法の異なる実
施例を、掘削された地下空間１０に未凍土１４の上下で
凍土１５を形成する場合について図４により説明する。
冷却体１１−１、１１−２によって未凍土１４の部分を
挟んで上下に並列配置し、冷凍装置からパイプラインＰ
を通して冷熱エネルギの供給を受ける冷却体１１−１お
よび１１−２の掘削壁部１３に対面する区域一体が、流
動体とともに凍土１５となり、冷却体の配置されていな
い一定の深さは未凍土１４のままに区分された施工がで
きる。この場合、上記冷却体相互の上下間隔を広げるの
と同様な熱伝導作用を得るために、上記未凍土１４の部
分に熱伝導率の低い汚泥を注入することによっても前記
同様の局部的な地盤凍結を達成させることが可能であ
る。Next, a different embodiment of the ground freezing construction method of the present invention will be described with reference to FIG. 4 in which the frozen soil 15 is formed above and below the unfrosted soil 14 in the excavated underground space 10.
The uncooled soil 14 is sandwiched between the cooling bodies 11-1 and 11-2 and arranged in parallel in the vertical direction.
The area of the cooling bodies 11-1 and 11-2 facing the excavation wall portion 13 that receives the supply of cold energy through the water forms the frozen soil 15 together with the fluid, and the unfrozen soil 14 has a certain depth where the cooling bodies are not arranged. It is possible to perform construction divided as it is. In this case, in order to obtain a heat conduction effect similar to widening the vertical interval between the cooling bodies, by injecting sludge having a low heat conductivity into the unfrozen soil 14, the same local ground as the above is obtained. Freezing can be achieved.
【００２３】[0023]
【発明の効果】以上記載した如く本発明によれば、従
来、凍結地点で目標通りの掘削精度が得難く、点状の限
られた範囲でしかも凍結速度が遅く、長い工期を要して
いた棒状冷却管による凍結工法や、冷却管を挿通した断
熱製の板状冷却体を用いる凍結工法では短工期の効率的
な急速凍結が実現し得なかったが、広い面積の良熱導伝
性の板状冷却体を用い且つ地下を掘削した空間に、その
地盤壁部の飽水土よりも高い熱伝導率をもつ汚泥の如き
流動体を注入充填することによって、上記板状冷却板に
冷却エネルギを給送循環するようにした結果、流動性あ
る汚泥が掘削空間に隙間なく行きわたって、広面積の上
記板状冷却体と全面的に接触し、凍結すべき地盤に対し
て上記流動性汚泥が熱伝導を援けて凍結が加速され、高
効率の凍土化を可能とし、工期の短縮並びに省エネルギ
にも資することとなる他、工事現場の状況に応じた冷凍
装置を選択的に設置することができる等、地盤凍結工事
方法として著効を奏するものである。As described above, according to the present invention, it has been difficult to obtain the desired excavation accuracy at the freezing point, the point has a limited range, the freezing speed is slow, and a long construction period is required. The freezing method using a rod-shaped cooling pipe or the freezing method using a heat insulating plate-shaped cooling body with a cooling pipe inserted could not realize efficient rapid freezing in a short period of time, but it has a good thermal conductivity in a large area. Cooling energy is applied to the plate-shaped cooling plate by injecting and filling a fluid such as sludge having a higher thermal conductivity than the saturated soil of the ground wall into the space excavated underground using the plate-shaped cooling plate. As a result of the feeding and circulation, the fluid sludge spreads over the excavation space without any gaps, making full contact with the large-area plate-shaped cooling body, and the fluid sludge with respect to the ground to be frozen. Freezing is accelerated by assisting heat conduction, enabling highly efficient frozen soil And, in addition to the also contribute to reducing and energy saving of the construction period, etc. can be selectively installed refrigeration apparatus according to the situation of the construction site, in which exhibits remarkable effects as a ground frozen construction methods.
【図１】本発明の実施例に係る地盤凍結工事方法の概説
図で、（Ａ）はブライン方式、（Ｂ）は液下ガス方式の
冷凍装置による実施例である。FIG. 1 is a schematic view of a ground freezing construction method according to an embodiment of the present invention, in which (A) is a brine system and (B) is a submersible gas system refrigeration system.
【図２】本発明の地盤凍結工事方法における板状冷却体
の異なる実施例を表す縦断面図で、（Ａ）は平板タンク
型、（Ｂ）はヘアピンコイル型、（Ｃ）はアイスパネル
型を示す。FIG. 2 is a vertical cross-sectional view showing another embodiment of a plate-shaped cooling body in the ground freezing construction method of the present invention, (A) is a flat plate tank type, (B) is a hairpin coil type, and (C) is an ice panel type. Indicates.
【図３】（Ａ）はパイロット孔の縦断側面図、（Ｂ）は
スリット掘削空間の縦断側面図、（Ｃ）冷却体の投入並
びに流動体を注入した地下空間の縦断側面図である。3A is a vertical side view of a pilot hole, FIG. 3B is a vertical side view of a slit excavation space, and FIG. 3C is a vertical side view of an underground space into which a cooling body is charged and a fluid is injected.
【図４】本発明の地盤凍結工事方法の異なる実施例の説
明図である。FIG. 4 is an explanatory view of a different embodiment of the ground freezing construction method of the present invention.
【図５】棒状冷却管による従来の土壌凍結法（従来の第
１技術）の説明図である。FIG. 5 is an explanatory diagram of a conventional soil freezing method using a rod-shaped cooling pipe (conventional first technique).
【図６】油圧モータ駆動式スリット掘削機を地下空間に
実装した縦断側面図（Ａ）、及び上面図（Ｂ）である。FIG. 6 is a vertical sectional side view (A) and a top view (B) in which a hydraulic motor-driven slit excavator is mounted in an underground space.
Ｒ 冷凍装置 １０ 地下空間 １１、１１−１、１１−２ 板状冷却体 １３ 掘削壁部 １４ 未凍土 １５ 凍土 １６ 流動体 Ｈ ハンガ Ｐ、Ｐ1、Ｐ2 パイプラインR Refrigerator 10 Underground space 11, 11-1, 11-2 Plate cooling body 13 Excavation wall part 14 Unfrozen soil 15 Frozen soil 16 Fluid H Hanger P, P 1 , P 2 Pipeline
フロントページの続き (72)発明者 井上 一敏 東京都千代田区岩本町３丁目10番１号 三 井建設株式会社内Front page continuation (72) Inventor Kazutoshi Inoue 3-10-1, Iwamotocho, Chiyoda-ku, Tokyo Mitsui Construction Co., Ltd.
Claims (3)
下を凍土化する工事方法において、前記棟土化地点の前
記地表面下に所要の掘削空間を設け、該掘削空間に冷却
体を投入するとともに、該掘削空間の周囲地盤の飽水土
が有する熱的性質よりも高熱伝導率をもつ流動体を注入
充填し、上記冷却体に対して冷凍装置から冷熱エネルギ
ーを給送することにより、上記流動体を介して上記冷却
体の周囲から掘削地盤の壁部に至る範囲一帯を凍結する
ようにしたことを特徴とする地盤凍結工事方法。1. A method of constructing frozen soil below the ground surface around an excavation point prior to underground construction, wherein a required excavation space is provided below the ground surface at the embankment point, and a cooling body is provided in the excavation space. While charging, by injecting and filling with a fluid having a higher thermal conductivity than the thermal property of the saturated soil of the ground around the excavation space, by feeding cold energy from the refrigerating device to the cooling body, A ground freezing construction method, characterized in that the entire area from the periphery of the cooling body to the wall of the excavated ground is frozen via the fluid.
的に平面状冷却体であることを特徴とする前記請求項１
に記載の地盤凍結工事方法。2. The cooling body introduced into the excavation space is a substantially planar cooling body.
Ground freezing construction method described in.
方式の冷凍装置から冷熱エネルギを給送可能としたこと
を特徴とする前記請求項１に記載の地盤凍結工事方法。3. The ground freezing construction method according to claim 1, wherein the refrigerating apparatus is capable of supplying cold energy from a brine type or liquefied gas type refrigerating apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30756992A JPH06136738A (en) | 1992-10-21 | 1992-10-21 | Ground freezing construction method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30756992A JPH06136738A (en) | 1992-10-21 | 1992-10-21 | Ground freezing construction method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06136738A true JPH06136738A (en) | 1994-05-17 |
Family
ID=17970659
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30756992A Pending JPH06136738A (en) | 1992-10-21 | 1992-10-21 | Ground freezing construction method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06136738A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006241905A (en) * | 2005-03-04 | 2006-09-14 | Kajima Corp | Heat conductive material |
| JP2008069246A (en) * | 2006-09-13 | 2008-03-27 | Kajima Corp | Material for freezing use, and ground freezing working method |
| CN102954982A (en) * | 2012-11-01 | 2013-03-06 | 浙江陆特能源科技有限公司 | Underground soil thermophysical property tester |
| WO2016098367A1 (en) * | 2014-12-19 | 2016-06-23 | ケミカルグラウト株式会社 | Ground freezing construction method and ground freezing system |
| JP2019108766A (en) * | 2017-12-20 | 2019-07-04 | 東京電力ホールディングス株式会社 | Maintenance method of frozen soil and construction method of frozen soil |
| CN113356858A (en) * | 2021-07-13 | 2021-09-07 | 中煤第一建设有限公司 | Non-equal-strength composite freezing wall freezing method |
| CN113933337A (en) * | 2021-10-13 | 2022-01-14 | 中国矿业大学 | Boundary active constraint bidirectional freezing and frost heaving test device and use method thereof |
-
1992
- 1992-10-21 JP JP30756992A patent/JPH06136738A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006241905A (en) * | 2005-03-04 | 2006-09-14 | Kajima Corp | Heat conductive material |
| JP2008069246A (en) * | 2006-09-13 | 2008-03-27 | Kajima Corp | Material for freezing use, and ground freezing working method |
| CN102954982A (en) * | 2012-11-01 | 2013-03-06 | 浙江陆特能源科技有限公司 | Underground soil thermophysical property tester |
| WO2016098367A1 (en) * | 2014-12-19 | 2016-06-23 | ケミカルグラウト株式会社 | Ground freezing construction method and ground freezing system |
| JP2016118024A (en) * | 2014-12-19 | 2016-06-30 | ケミカルグラウト株式会社 | Ground freezing method and ground freezing system |
| EP3235955A4 (en) * | 2014-12-19 | 2018-08-15 | Chemical Grouting Co.Ltd. | Ground freezing construction method and ground freezing system |
| US10221537B2 (en) * | 2014-12-19 | 2019-03-05 | Chemical Grouting Co., Ltd. | Artificial ground freezing method and artificial ground freezing system |
| JP2019108766A (en) * | 2017-12-20 | 2019-07-04 | 東京電力ホールディングス株式会社 | Maintenance method of frozen soil and construction method of frozen soil |
| CN113356858A (en) * | 2021-07-13 | 2021-09-07 | 中煤第一建设有限公司 | Non-equal-strength composite freezing wall freezing method |
| CN113356858B (en) * | 2021-07-13 | 2023-02-28 | 中煤第一建设有限公司 | Non-equal-strength composite freezing wall freezing method |
| CN113933337A (en) * | 2021-10-13 | 2022-01-14 | 中国矿业大学 | Boundary active constraint bidirectional freezing and frost heaving test device and use method thereof |
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