JPH1121872A - Method and device for improving weak layer ground of lower part of stone bond layer - Google Patents
Method and device for improving weak layer ground of lower part of stone bond layerInfo
- Publication number
- JPH1121872A JPH1121872A JP9187190A JP18719097A JPH1121872A JP H1121872 A JPH1121872 A JP H1121872A JP 9187190 A JP9187190 A JP 9187190A JP 18719097 A JP18719097 A JP 18719097A JP H1121872 A JPH1121872 A JP H1121872A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- stone
- auger
- bit
- blade
- 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.)
- Granted
Links
Landscapes
- Earth Drilling (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、港湾の護岸等が設置さ
れた部分における海底の軟弱地盤の改良に係り、特に、
例えば軟弱層の上部に砂層を設置し、その上に破砕石層
である捨石マウンド層を敷設した状態で、その上部に護
岸が構築された形式の従来型港湾施設における、捨石マ
ウンド層である積石層下部の軟弱層の土質改良に係る新
規な工法及びそのための装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the improvement of soft ground on the seabed in a portion where a seawall of a port is installed.
For example, a sand layer is placed above a soft layer, and a rubble mound layer, which is a crushed stone layer, is laid on top of it, and a rubble mound layer in a conventional port facility with a seawall built on top of it. The present invention relates to a novel method for improving the soil quality of a soft layer below a stone layer and an apparatus therefor.
【０００２】[0002]
【従来の技術】最近、海底の軟弱層の土質を改良した後
に護岸が構築される事例もあるが、過去に構築された一
般的な港湾の護岸等は、概ね海底の軟弱層の上に計画に
より計算された或る厚さの砂層を設置し、更にその上部
に直径が２０cm〜１００cm程度の破砕石にて構成される
捨石マウンド層を築造し、その上部に各種の方法にて護
岸が構築されている。2. Description of the Related Art In recent years, there has been a case where seawalls are constructed after improving the soil quality of a soft layer on the seabed. However, seawalls and seawalls constructed in the past are generally planned on the seabed on the soft layer. A sand layer of a certain thickness calculated by the above is installed, and a rubble mound layer composed of crushed stone with a diameter of about 20 cm to 100 cm is built on top of it, and seawalls are built on top of it by various methods Have been.
【０００３】この様な旧式の護岸における捨石層を貫通
して、その下部の軟弱層の土質を改良し、地震その他の
地質変化に対応する場合には、強力なトルクと切刃ビッ
トを有するロックオ−ガを用いて捨石層の破砕石を切砕
し、土質改良手段を軟弱層まで到達させて行う次の様な
方法が知られている。 高圧ジェット固結液の噴射により改良面積円を拡大さ
せて軟弱層を土質改良する方法。 機械的に拡大翼を伸長させて、固結液と軟弱土砂とを
機械的に撹拌混合させて土質改良する方法。 上記２方法を同時に行う方法。[0003] In the case of penetrating the rubble layer in such an old revetment and improving the soil quality of the soft layer thereunder to cope with earthquakes and other geological changes, a rock and rock having a strong torque and a cutting bit is required. The following method is known in which a crushed stone in a rubble layer is crushed using a moth, and soil improvement means is reached to a soft layer. A method of improving the soil quality of a soft layer by expanding the improvement area circle by spraying high-pressure jet consolidation liquid. A method of mechanically extending the expanding wings and mechanically stirring and mixing the consolidation liquid and soft earth and sand to improve soil quality. A method in which the above two methods are performed simultaneously.
【０００４】然し、上記の方法のみでは、高圧液の噴
射孔が極小であるために詰まる恐れがあり、充分なる撹
拌を行うにはその改良時間が長くなると同時に噴射孔が
詰まった時の処理が難しい。の方法では、機械混合撹
拌のために、粘性度の高い軟弱地盤においては均一な混
合撹拌が難しく、かつそれを行うには、混合撹拌に要す
る時間を充分に掛けねばなない。更にの方法はこれら
を併用した方法であって、軟弱土と固結液を混合撹拌す
ることにより軟弱層を削孔径よりも大きな平面径に渡っ
て地盤改良を行う方法である。However, with the above method alone, the injection hole for the high-pressure liquid may be clogged due to its extremely small size. To achieve sufficient stirring, the time required for the improvement is prolonged, and at the same time, the treatment when the injection hole is clogged is required. difficult. According to the method (1), it is difficult to perform uniform mixing and stirring on soft ground having high viscosity due to mechanical mixing and stirring. A further method is a method in which these are used in combination, and is a method of improving the ground over a plane diameter larger than the borehole diameter by mixing and stirring the soft soil and the consolidation liquid.
【０００５】この様な在来工法を図４乃至図１０により
具体的に説明する。第１の従来工法に使用される装置
は、図４により明らかなごとく回転ロッド０２の先端に
削孔用のビット０３が装着されており、ビット０３の下
部の吐出口０４から液状物を吐出又は噴射させ、ビット
０３の上部には拡縮自在な撹拌翼０５が装着され、その
上部に略水平方向に向けて高圧の液状物を噴射する水平
ノズル０６が設けられ、更にその上方位置に斜め下方向
に高圧の液状物を噴射する傾斜ノズル０７が設けられた
概略構造である。[0005] Such a conventional construction method will be specifically described with reference to FIGS. As shown in FIG. 4, the apparatus used in the first conventional method has a drilling bit 03 attached to the tip of a rotating rod 02, and discharges or discharges a liquid material from a discharge port 04 below the bit 03. An expandable and contractible stirring blade 05 is mounted on the upper part of the bit 03, and a horizontal nozzle 06 for injecting a high-pressure liquid material in a substantially horizontal direction is provided on the upper part thereof. This is a schematic structure in which an inclined nozzle 07 for injecting a high-pressure liquid material is provided.
【０００６】この様な装置により、先ず吐出口０４から
液状物を吐出又は噴射しつつ、ロッド０２を回転させな
がらビット０３にて地盤Ｅを削孔して、一般的に転石混
じりの硬質地盤Ｅ１、軟弱地盤（要改良土質）Ｅ２と掘
進して所定の深度である下部硬質地盤Ｅ３に達した後、
回転ロッド０２を逆回転させることにより拡縮自在な撹
拌翼０５を拡翼させる。次いで、図５、図６に示すごと
き高圧の液状物ノズルである水平ノズル及び傾斜ノズル
０６、０７から周知の固結用液を高圧噴射させながら、
回転ロッド０２を引き上げることにより軟弱地盤Ｅ２の
土質を改良する。所定の上方部位置即ち軟弱地盤上方部
位に達した後、回転ロッド０２を正回転させて拡縮自在
な撹拌翼０５を縮翼させると共に、高圧の液状物ノズル
０６、０７からの固結用液の高圧噴射を止めて、回転ロ
ッド０２を引き抜くことにより地盤の中間層のみを改良
（ＥＦ部分）する工法である。With such an apparatus, the ground E is first drilled with the bit 03 while rotating the rod 02 while discharging or jetting a liquid material from the discharge port 04. After digging with the soft ground (improved soil quality) E2 and reaching the lower hard ground E3 at a predetermined depth,
By rotating the rotating rod 02 in the reverse direction, the expandable and contractable stirring blade 05 is expanded. Next, while injecting a well-known consolidation liquid from the horizontal nozzles and the inclined nozzles 06 and 07, which are high-pressure liquid nozzles as shown in FIGS.
By raising the rotating rod 02, the soil quality of the soft ground E2 is improved. After reaching the predetermined upper position, that is, the upper part of the soft ground, the rotating rod 02 is rotated forward to cause the expandable / contractible agitating blade 05 to contract, and the liquid for consolidation from the high-pressure liquid nozzles 06 and 07 is discharged. This is a method of improving only the middle layer of the ground (EF portion) by stopping the high pressure injection and pulling out the rotating rod 02.
【０００７】しかし、この様な工法にあっては、上部の
硬質地盤Ｅ１が粗い密度の玉石或いは礫で構成されてい
る場合には、回転ロッド０２を引き抜く際に、玉石或い
は礫層の掘削孔壁０８が崩壊し、降下時に掘削した小掘
削孔０９内に、崩れた玉石或いは礫が落下して埋もれる
ことがある。その場合、拡縮自在な攪拌翼０５と削孔用
ビット０３とならなる出っ張り部が障害となり、改良装
置全体を引き抜くことができなくなる等の欠点を有して
いた。However, in such a construction method, when the upper hard ground E1 is made of coarse boulders or gravel, the drilling hole of the boulders or gravel layer is formed when the rotating rod 02 is pulled out. The wall 08 collapses, and broken cobblestones or gravel may fall and become buried in the small excavation hole 09 excavated at the time of descent. In this case, the projecting portion serving as the expandable / contractible stirring blade 05 and the drill bit 03 becomes an obstacle, and has a drawback in that the entire improvement device cannot be pulled out.
【０００８】図７乃至図９に示す第２の在来工法は、や
はり地盤Ｅ下方においてその中間層の軟弱地盤Ｅ２を改
良する装置並びに工法である。従来公知のピッチの大き
な螺旋翼１０を有する硬質ロッド０２の先端に、ロック
削孔用ビット０３を装着し、その上部に開閉式となった
撹拌翼０５が設けられ、上方の玉石混じり砂礫地盤Ｅ１
を降下削孔していく際には撹拌翼０５を削孔方向、即ち
ロッド０２に沿って垂直方向に閉翼装着しておき、地盤
改良目的の軟弱地盤Ｅ２に到達すると、ロッド０２内側
から油圧装置等により開閉式に撹拌翼０５を垂直方向か
ら水平方向に開き（図８参照）、軟弱地盤Ｅ２の土砂を
ビット０３の先端の吐出口０４から吐出される固結用液
と混合させつつ、該地盤Ｅ２を改良して改良部ＥＦと
し、所定の深度に到達すると撹拌翼０５にて混合撹拌し
つつロッド０２を引き上げ、上方の目的深度即ち軟弱改
良地盤Ｅ２の上端まで引き上げが完了すると、油圧装置
により撹拌翼０５を降下削孔時と同じように垂直方向に
ロッド０２に沿って閉翼装置し、下降時に掘削された掘
削孔０９より引き抜く工法（図９参照）がある。The second conventional construction method shown in FIGS. 7 to 9 is an apparatus and a construction method for improving the soft ground E2 in the middle layer below the ground E. A lock drill bit 03 is attached to the tip of a conventionally known hard rod 02 having a large spiral blade 10 having a large pitch, and an openable / closable stirring blade 05 is provided on the top thereof.
When the drilling is performed, the stirring blade 05 is mounted in the drilling direction, that is, in the vertical direction along the rod 02. When the blade reaches the soft ground E2 for the purpose of ground improvement, the hydraulic pressure is applied from the inside of the rod 02. The stirrer blades 05 are opened and closed by a device or the like in the horizontal direction from the vertical direction to the horizontal direction (see FIG. 8), and while the soil of the soft ground E2 is mixed with the consolidation liquid discharged from the discharge port 04 at the tip of the bit 03, The ground E2 is improved to form an improved portion EF. When the ground E2 reaches a predetermined depth, the rod 02 is pulled up while being mixed and stirred by the stirring blades 05. When the raising is completed to the upper target depth, that is, the upper end of the soft improved ground E2, the hydraulic pressure is increased. There is a construction method in which the agitating blade 05 is vertically closed along the rod 02 in the same manner as in the case of the down drilling by the apparatus, and is withdrawn from the excavation hole 09 excavated at the time of descending (see FIG. 9).
【０００９】しかし、この様な工法においても、上部の
地盤Ｅ１が良く締まった硬質地盤の場合には大した問題
は生じないが、玉石や礫を主体とした粗い密度の地盤で
ある場合、即ち捨石マウンド層のごとき場合には、降下
削孔時に造成した土砂混合の削孔０９に、掘削孔周辺の
玉石並びに礫が崩壊落下し、垂直方向に畳まれた開閉式
の撹拌翼０５である出っ張り部分並びに削孔ビット０３
の出っ張り部分が障害となって、改良装置全体を引き抜
くことができなくなる欠点を有していた。[0009] However, even in such a construction method, no significant problem occurs when the upper ground E1 is a hard ground that is well-tightened, but when the ground is coarse ground mainly composed of boulders or gravel, ie, In the case of a rubble mound layer, a cobblestone and gravels around the excavation hole collapse and drop into the drilled hole 09 made of earth and sand at the time of drilling, and the opening and closing type stirring blade 05 is folded vertically. Part and drill bit 03
Has a drawback in that the projecting portion becomes an obstacle and the entire improved device cannot be pulled out.
【００１０】図１０は、上記図７乃至図９のごとき従来
工法を用いて、港湾施設の一部である既設の護岸の下層
部軟弱地盤を改良する工程に関する説明図である。旧式
工法に依る港湾施設は一般に、軟弱地盤Ｅ２の上部にあ
る程度の砂層を施した後、直径が約２０cm〜１００cmの
破砕石Ｓからなる捨石マウンド層Ｅ１を造成し、その上
に堤防等の構築物Ｍを設置すると共に、その内部水域を
埋立てる等して種々の港湾施設が建設されている。FIG. 10 is an explanatory view showing a process of improving the soft ground under the existing revetment which is a part of the port facility by using the conventional method as shown in FIGS. 7 to 9 described above. In general, a port facility based on the old-fashioned method forms a rubble mound layer E1 made of crushed stone S having a diameter of about 20 to 100 cm after applying a certain amount of sand layer on the soft ground E2, and constructing a dike or the like thereon. Various port facilities have been constructed by installing M and reclaiming its internal water area.
【００１１】この様な旧式工法による港湾施設等が設置
された部分の軟弱地盤における、例えば地震対策等の目
的で、既設の上層部捨石マウンドＥ１を掘削し、その下
層である軟弱地盤Ｅ２のみを地盤改良するには、該図１
０に示すように、一般にはロッド外周にピッチの大きな
螺旋翼１０を設けた所謂硬質ロッド０２の先端に、ビッ
ト０３及び任意数の開閉式の撹拌翼０５を備えたロック
オーガを用いて行っている。For the purpose of, for example, earthquake countermeasures, the existing upper layer rubble mound E1 is excavated in the soft ground in the portion where the harbor facilities and the like by the old construction method are installed, and only the soft ground E2 as the lower layer is excavated. To improve the ground,
As shown in FIG. 0, generally, a so-called hard rod 02 having a spiral wing 10 with a large pitch provided on the outer periphery of a rod is used at the tip of a so-called hard rod 02 using a rock auger provided with a bit 03 and an arbitrary number of openable / closable stirring blades 05. I have.
【００１２】この場合、上記の従来例における説明でも
明らかな様に、開閉式の撹拌翼０５を折り畳んだ状態で
捨石マウンドＥ１を掘削し、次いで攪拌翼を閉翼して軟
弱地盤Ｅ２を改良した後、再び開閉式の撹拌翼０５を折
り畳んだ状態でロックオーガを抜き上げるのであるが、
該軟弱地盤改良作業中に図示のごとく、捨石Ｓの端部Ｓ
Ｅが各所において掘削孔０９内に入り込んでくる。その
理由は、上記捨石マウンドが破砕石Ｓのみにより形成さ
れていて、これらの破砕石Ｓは例えば堆積土等により相
互に結合されていないので、オーガの掘削振動等によっ
て容易に滑動し、例えば図示のごとく硬質ロッドの螺旋
翼間に入り込み、結局これらの滑動破砕石の為にオーガ
の抜き上げが不能となってしまうのである。In this case, as is clear from the description of the conventional example, the rubble mound E1 is excavated in a state where the openable stirring blade 05 is folded, and then the stirring blade is closed to improve the soft ground E2. Later, the rock auger is pulled out with the openable stirring blade 05 folded again,
During the soft ground improvement work, as shown in FIG.
E enters the borehole 09 at various places. The reason is that the rubble mound is formed only by the crushed stones S, and since these crushed stones S are not mutually connected by, for example, sedimentary soil or the like, they easily slide by the auger excavation vibration or the like. As described above, they penetrate between the spiral wings of the hard rod, and eventually these sliding crushed stones make it impossible to pull out the auger.
【００１３】[0013]
【発明が解決しようとする課題】これら公知の装置及び
工法は、捨石層の下部の軟弱地盤層を改良する工法自体
について見れば適当であると思われる。しかし、この様
な軟弱層地盤の改良にあっては、ある位置において軟弱
層を改良した後これらの装置を抜き取り、次の例えば隣
接位置で繰り返し新たな作業に入るために、強力なロッ
ク用切刃ビットで破砕石の積石により構成されている捨
石層を切砕削孔する必要があるが、捨石層は自然的に積
み重ねて組成されているために、比較的粗い密度であ
る。そのため、捨石層の一部の破砕石は切砕されるが、
他の多くの破砕石は強力なロックビットのトルクによ
り、ロックビットの外側の層内即ち外周部の破砕石間に
押し込まれる場合が多い。そして、該押し込まれた積石
は、ロックビットの通過後ロッドの掘削振動等によって
掘削孔内に戻り、地盤改良装置を引き抜く際に、地盤改
良用撹拌機械装置を該掘削孔内に再び移動された上記積
石が妨害し、その引き抜きを不能とする不具合があっ
た。本発明は、この様な不具合を解消し、作業が確実で
作業性の高い積石層下部の軟弱層地盤の改良工法及びそ
のための装置を提供するものである。These known devices and methods seem to be appropriate in view of the method of improving the soft ground layer below the rubble layer. However, in such improvement of the soft layer ground, after the soft layer is improved at a certain position, these devices are withdrawn, and then, for example, a new work is repeatedly performed at an adjacent position. It is necessary to cut and drill a rubble layer made of crushed stone with a blade bit, but the rubble layer has a relatively coarse density because it is naturally stacked and composed. Therefore, some crushed stones in the rubble layer are cut,
Many other crushed stones are often pushed into the outer layer of the lock bit, i.e., between the crushed stones at the outer periphery, by the strong rock bit torque. Then, the pushed stone is returned into the excavation hole by the excavation vibration of the rod after passing through the lock bit, and when the ground improvement device is pulled out, the ground improvement agitating machine is moved again into the excavation hole. Further, there was a problem that the above-mentioned stones were obstructed, making it impossible to pull out the stones. The present invention is to solve such a problem and to provide an improved construction method for a soft ground under a stone layer, which is reliable and has high workability, and an apparatus therefor.
【００１４】[0014]
【課題を解決するための手段】強力なトルクで捨石層を
掘削可能なロックビットと、高圧固結液噴射口と、拡縮
可能な攪拌翼とを有するロックオーガであって、該オー
ガのロッドには該攪拌翼の縮翼状態外径より大きい径で
且つそのピッチが掘削される積石層の捨石の平均直径よ
りも小さい螺旋翼を設けた上記ロックオーガを用い、該
ロックオーガの攪拌翼を縮翼状態でビットにより積石層
を掘削し、続いて軟弱層を該ビット及び噴射口からの圧
力流体により掘削すると共に、上記攪拌翼を拡翼して固
結剤と軟弱掘削土を攪拌混合し、その後該攪拌翼を縮翼
した状態で且つ上記螺旋翼の端部で上記捨石層の積石の
滑動による掘削孔の閉塞を防止しながら、ロックオーガ
を上記積石層上部まで抜出す操作を繰り返すことを特徴
とする積石層下部の軟弱地盤を改良する工法、及び、捨
石層からなる積石を掘削可能なロックオーガであり、回
転ロッドの先端に固結液噴射口とロックビットを有し、
その上部に拡縮自在な複数の攪拌翼と、水平方向及び下
方傾斜方向に液体を噴射する噴射口と、更に上方のロッ
ドには、該攪拌翼の縮翼時の外径よりもやや大きな外径
であってそのピッチが掘削される積石の平均的直径より
小さい螺旋翼を、少なくとも改良作業時に該ロッドが最
下点まで嵌入された状態でのその捨石層面より上方位置
まで設けられていることを特徴とする積石層下部の軟弱
地盤を改良するための装置である。A lock auger having a lock bit capable of excavating a rubble layer with a strong torque, a high-pressure consolidating liquid injection port, and a scalable impeller, wherein a rod of the auger is provided. Is a rock auger provided with a spiral blade having a diameter larger than the outer diameter of the impeller in the impeller state and having a pitch smaller than the average diameter of the rubble of the stone layer to be excavated. The rock layer is excavated by the bit in the contracted state, and the soft layer is excavated by the pressurized fluid from the bit and the injection port, and the agitating blade is expanded to mix the binder and the soft excavated soil. Then, an operation of extracting the rock auger up to the upper part of the piling stone layer while the stirring blade is being compressed and preventing the excavation hole from being blocked by the sliding of the piling stone of the rubble layer at the end of the spiral blade. The lower part of the stone layer characterized by repeating Method for improving soft ground, and a excavation lock auger a product stone consisting of rubble layer has a consolidating liquid injection port and the lock bit to the tip of the rotary rod,
A plurality of expandable / shrinkable stirring blades at the upper part thereof, an injection port for injecting liquid in the horizontal and downward inclined directions, and an outer diameter slightly larger than the outer diameter of the stirring blade at the time of the blade shrinkage. A spiral wing whose pitch is smaller than the average diameter of the stone to be excavated is provided at least above the surface of the rubble layer in a state where the rod is fitted to the lowest point at the time of improvement work. This is a device for improving soft ground under a stone layer, characterized by the following features.
【００１５】[0015]
【実施の形態】本発明の詳細を図１乃至図３により説明
する。図１は、本発明に係る工法を実施するためのロッ
クオーガの一部を概念的に示すもので、通常のロックオ
ーガ同様に任意の支承手段及び回転駆動手段（図示せ
ず）により駆動されるオーガ軸１２の先端部には、掘削
ビット１３及び地盤改良剤用又は補助掘削用の高圧流体
噴射口１４を備えたいる。また、該掘削ビットの上部に
は例えば上下各一対の拡縮攪拌翼手段１５、１５及び同
じく上下に必要数の掘削用及び地盤改良剤用噴射口１
６、１６を有している。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described with reference to FIGS. FIG. 1 conceptually shows a part of a lock auger for carrying out a method according to the present invention, and is driven by any supporting means and a rotation driving means (not shown) like a normal lock auger. The tip of the auger shaft 12 is provided with a drill bit 13 and a high-pressure fluid injection port 14 for a ground improvement agent or for auxiliary drilling. In addition, for example, a pair of upper and lower expansion / contraction stirrer means 15 and 15 and upper and lower required numbers of excavating and ground improving agent injection ports 1 are provided above the excavating bit.
6 and 16.
【００１６】更に、本発明の装置においては、その特徴
点であるオーガ軸１２の略々全長に渡って、又は少なく
とも上方位置の拡縮翼１５が縮翼状態である（図中実
線）位置より上方から、該オーガ軸が施工中に嵌入され
る捨石層からなる地盤Ｅ上面位置に相当する位置の長さ
に渡って、可成り小さいピッチＰの螺旋翼２０を有して
いる。この場合、螺旋翼２０のピッチＰは理論的には掘
削される捨石層の破砕石Ｓの直径によりその上限が決定
されるが、少なくとも掘削時にビットのトルクにより掘
削孔外周部に押込まれた捨石の大部分が、再び滑動して
該螺旋翼の間に入り込むのを防止するために必要なピッ
チ間隔に設けられることが重要である。Furthermore, in the apparatus of the present invention, the expanding / contracting blade 15 at the upper position is located substantially over the entire length of the auger shaft 12 which is the characteristic point, or at least above the position where the expanding / contracting blade 15 is in the contracted state (solid line in the figure). Accordingly, the auger shaft has a spiral blade 20 having a considerably small pitch P over a length corresponding to the position of the upper surface of the ground E made of a rubble layer to be inserted during construction. In this case, the upper limit of the pitch P of the spiral blade 20 is theoretically determined by the diameter of the crushed stone S of the rubble layer to be excavated. It is important that the majority of be placed at the pitch spacing necessary to prevent it from sliding again into the spiral wing.
【００１７】図２Ａ、Ｂは、前記螺旋翼２０の外周部
と、例えば上下拡縮攪拌翼の拡翼時の外周軌跡との関係
を示す図であって、該図に明らかなごとく攪拌翼を縮翼
すると図に破線ｒで示すように、その外径寸法が上記螺
旋翼２０の外径の軌跡（符号２０で示す）内に収るよう
に構成されている。また、同図Ａ、Ｂから明らかなよう
に、例えば上下一対の攪拌翼１５、１５は互に位相が９
０゜ずれた位置に設けられるのが良く、同様に地盤改良
剤等の流体噴射口１６、１６も、なるべく９０゜位相の
異なる位置（図１参照）に設けることが好ましい。FIGS. 2A and 2B are diagrams showing the relationship between the outer peripheral portion of the spiral blade 20 and the outer peripheral trajectory of the vertical expanding / contracting stirring blade at the time of expanding the blade, for example. When the blade is winged, as shown by a broken line r in the figure, the outer diameter dimension is configured to be within the locus of the outer diameter of the spiral blade 20 (indicated by reference numeral 20). As is clear from FIGS. A and B, for example, the upper and lower stirring blades 15, 15 have a phase of 9
It is preferable to be provided at a position shifted by 0 °, and similarly, it is also preferable to provide the fluid injection ports 16 and 16 of the ground conditioner or the like at positions (see FIG. 1) having a phase difference of 90 ° as much as possible.
【００１８】図３は、上記本発明の装置を用いた新規な
施工法を説明するための説明図であって、これにより本
発明の工法を図１０の従来例と対比して説明する。図１
０と同様に旧式工法に依る港湾施設の軟弱層地盤Ｅ２上
には、一般的に砂層を施した後に直径が約２０cm〜１０
０cm程度の破砕石Ｓからなる捨石マウンド層Ｅ１が造成
されており、その上に堤防等の構築物Ｍが設置されてい
る。この様な構築物Ｍの基礎部である捨石マウンドＥ１
下部の軟弱地盤Ｅ２を、上記図１０と同様の方法によ
り、上記本発明に係る構造のオーガを用いて施工する。FIG. 3 is an explanatory view for explaining a new construction method using the above-described apparatus of the present invention. The method of the present invention will be described in comparison with the conventional example of FIG. FIG.
In the same way as in the case of No. 0, the diameter of about 20 cm to 10 cm is generally formed on the soft ground E2 of the port facility based on the old method after the sand layer is applied.
A rubble mound layer E1 made of crushed stone S of about 0 cm is formed, and a structure M such as a dike is installed thereon. Rubble mound E1 which is the foundation of such a structure M
The lower soft ground E2 is constructed using the auger having the structure according to the present invention in the same manner as in FIG.
【００１９】この場合、掘削ロッド１２の先端部に設け
たロックビット１３により捨石マウンドＥ１の破砕石Ｓ
を切砕削孔した後、攪拌翼１５により軟弱層地盤Ｅ２の
土と固結液を攪拌混合して地盤改良がなされる。ところ
で、本発明の工法においては、上記本発明の装置におい
て説明したごとく、従来公知の硬質ロッドに設けられた
螺旋翼よりも一般的には相当にピッチの短い螺旋翼を有
するロッドを用い、従来工法と同様に切砕削孔及び地盤
改良がなされる。この過程において、捨石マウンドＥ１
の各破砕石Ｓの内の多くはロックビット１３のトルクに
より外周に押出され、更に外周部にある破砕石の間隙等
に押込まれると同時に、その上部に位置する上記ピッチ
の短い螺旋翼端部により内方への滑動を阻止されてい
る。In this case, the crushed stone S of the rubble mound E1 is fixed by the lock bit 13 provided at the tip of the drill rod 12.
Is ground, and the soil of the soft ground E2 and the consolidation liquid are stirred and mixed by the stirring blades 15 to improve the ground. By the way, in the method of the present invention, as described in the above-described apparatus of the present invention, a rod having a spiral blade having a considerably shorter pitch than a spiral blade provided on a conventionally known hard rod is generally used. The drilling and ground improvement will be done in the same way as the construction method. In this process, rubble mound E1
Most of the crushed stones S are extruded to the outer periphery by the torque of the lock bit 13 and further pushed into the gaps of the crushed stones at the outer periphery, and at the same time, the spiral pitch of the short pitch located at the upper part thereof The part is prevented from sliding inward.
【００２０】次いで、軟弱地盤の土と固結液とを攪拌混
合後、攪拌翼を縮翼した状態で掘削ロッド１２を回転さ
せながら徐々のに引き抜くが、この場合、螺旋翼２０は
上記のごとく平均的破砕石の直径よりも小さいピッチＰ
に構成されているので、掘削孔１９の外周部に押込まれ
た破砕石は何れも上記螺旋翼外周端の何れかの部分に当
接した状態が維持されて、該螺旋翼間に入り込むことが
できない状態のまま引く抜かれる。この場合、掘削時に
切砕されない状態で外周方向に押し込まれた破砕石は、
その殆どの外径が上記螺旋翼のピッチＰよりも大きいも
のである点が重要である。従って、本発明工法に用いら
れるロックオーガの螺旋翼ピッチは、施工現場に積石さ
れている破砕石の平均的直径に適応した寸法のものを用
いることが重要である。また、この様にして引抜かれた
後の掘削孔１９内には、仮に周囲の破砕石が滑動して該
掘削孔内に落下しても全く不都合がなく、却って下部改
良地盤部の混合土と一体化されて強固な改良地盤が構成
されるものである。Next, after the soil of the soft ground and the consolidation liquid are stirred and mixed, the excavating rod 12 is gradually pulled out while rotating the excavating rod 12 in a state where the stirring blade is contracted. In this case, the spiral blade 20 is connected as described above. Pitch P smaller than average crushed stone diameter
Therefore, any crushed stone pushed into the outer peripheral portion of the excavation hole 19 is kept in contact with any part of the outer peripheral end of the spiral blade, and may enter between the spiral blades. It is pulled out in a state where it can not be done. In this case, the crushed stone pushed in the outer peripheral direction without being cut during excavation,
It is important that most of the outer diameter is larger than the pitch P of the spiral blade. Therefore, it is important that the pitch of the spiral wings of the rock auger used in the method of the present invention be a size adapted to the average diameter of the crushed stone piled on the construction site. In addition, in the excavation hole 19 after being pulled out in this way, even if the surrounding crushed stone slides and falls into the excavation hole, there is no inconvenience. It is integrated to form a solid improved ground.
【００２１】[0021]
【効果】本発明の第１の効果は、ロックビットにて掘削
孔時に切砕された破砕片は、螺旋翼の羽に乗せられて上
方に運ばれるが、破砕されない捨石は、地盤が粗い密度
の積石層であるため掘削孔外周の積石層の破砕石間隙に
押し込められる。ここで、螺旋翼のピッチが大きい場合
には、一度押込まれた破砕石が掘削ロッドの振動で掘削
孔中へ戻り、該ロッドの回転に支障が生じるが、螺旋翼
の間隔が例えば２０cm程度の短い間隔の場合には、掘削
孔中に戻りかかった石が回転する螺旋翼端に押されて再
び積石層の中に押し込まれる。また第２に、上記のごと
き現象を繰り返すことにより、掘削孔の周囲の積石層の
粗い密度状態が厚密な状態に変わり、地盤改良装置を引
き上げる時には該掘削孔の外周の石が掘削孔内に移動す
ることが無くなり、容易に装置を引き上げることができ
て、装置の引き抜き不能な現象を防止することができ
る。更に第３に、螺旋翼のピッチを短くすることにより
掘削ロッドの剛性がより高くなり、粗い密度の積石層を
掘削する場合に生ずる滑り現象による、堅孔（掘削孔）
の曲りを防止することができると言う格別の作用効果を
も奏する。[Effect] The first effect of the present invention is that the crushed pieces cut at the time of the drilling hole by the rock bit are carried upward by being put on the wings of the spiral wing, but the crushed stone that is not crushed has a rough ground. Because it is a piling stone layer, it is pushed into the crushed stone gap of the piling stone layer around the drilling hole. Here, when the pitch of the spiral blades is large, the crushed stone once pushed back into the drilling hole due to the vibration of the drilling rod and hinders the rotation of the rod, but the interval between the spiral blades is, for example, about 20 cm. In the case of a short interval, the stone that has returned into the wellbore is pushed by the rotating spiral blade tip and is pushed again into the bedrock layer. Secondly, by repeating the above-mentioned phenomenon, the coarse density state of the stone layer around the excavation hole changes to a dense state, and when the ground improvement device is pulled up, the stone on the outer periphery of the excavation hole is excavated. The device can be easily lifted up, and the phenomenon that the device cannot be pulled out can be prevented. Thirdly, by shortening the pitch of the spiral blades, the rigidity of the drilling rod is increased, and a solid hole (drilled hole) due to a sliding phenomenon that occurs when drilling a coarse-densed stone layer.
It also has an extraordinary effect of being able to prevent bending.
【図１】本発明の装置における掘削軸部分の側面図であ
る。FIG. 1 is a side view of a digging shaft portion of the apparatus of the present invention.
【図２】図１に示す掘削軸の各攪拌翼上部からみた平面
図である。FIG. 2 is a plan view of the excavating shaft shown in FIG. 1 as viewed from above each stirring blade.
【図３】本発明の工法の施工状態を説明する概念図であ
る。FIG. 3 is a conceptual diagram illustrating a construction state of the construction method of the present invention.
【図４】従来工法を説明する概念図である。FIG. 4 is a conceptual diagram illustrating a conventional method.
【図５】図４同様の工法経過説明概念図である。FIG. 5 is a conceptual diagram illustrating the progress of a method similar to FIG.
【図６】図５と同様の概念図である。FIG. 6 is a conceptual diagram similar to FIG.
【図７】他の従来工法を説明する概念図である。FIG. 7 is a conceptual diagram illustrating another conventional method.
【図８】図７同様の工法の経過説明概念図である。FIG. 8 is a conceptual diagram illustrating the progress of a method similar to FIG.
【図９】図８と同様の概念図である。FIG. 9 is a conceptual diagram similar to FIG.
【図１０】従来工法の施工状態を説明する概念図であ
る。FIG. 10 is a conceptual diagram illustrating a construction state of a conventional method.
０２、１２ 掘削ロッド ０３、１３ 掘削ビット ０４、０６、０７、１４、１６ 流体噴射口 ０５、１５ 拡縮攪拌翼 Ｅ１ 捨石マウンド Ｅ２ 軟弱地盤 Ｅ３ 下部硬質地盤 ＥＦ 地盤改良部位 Ｓ 積石 Ｍ 防波堤 02,12 Drilling rod 03,13 Drilling bit 04,06,07,14,16 Fluid injection port 05,15 Expansion / contraction stirrer blade E1 Ripstone mound E2 Soft ground E3 Lower hard ground EF Ground improvement site S Stone mound Breakwater
Claims (4)
クビットと、高圧固結液噴射口と、拡縮可能な攪拌翼と
を有するロックオーガであって、該オーガのロッドには
該攪拌翼の縮翼状態外径より大きい径で且つそのピッチ
が掘削される積石層の捨石の平均直径よりも小さい螺旋
翼を設けた上記ロックオーガを用い、該ロックオーガの
攪拌翼を縮翼状態でビットにより積石層を掘削し、続い
て軟弱層を該ビット及び噴射口からの圧力流体により掘
削すると共に、上記攪拌翼を拡翼して固結剤と軟弱掘削
土を攪拌混合し、その後該攪拌翼を縮翼した状態で且つ
上記螺旋翼の端部で上記捨石層の積石の滑動による掘削
孔の閉塞を防止しながら、ロックオーガを上記積石層上
部まで抜出す操作を繰り返すことを特徴とする積石層下
部の軟弱地盤を改良する工法。1. A lock auger having a lock bit capable of excavating a rubble layer with a strong torque, a high-pressure consolidating liquid injection port, and a stirring blade which can be expanded and contracted. The rock auger provided with spiral wings having a diameter larger than the outer diameter of the crushed stone layer and a pitch smaller than the average diameter of the rubble of the stone layer to be excavated is used, and the stirring blades of the rock auger are set in the crushed state. Excavation of the stone layer by the bit, and then excavation of the soft layer by the pressurized fluid from the bit and the injection port, and the agitating blades are spread to mix and mix the binder and the soft excavated soil. Repeating the operation of extracting the rock auger to the upper part of the piling stone layer while preventing the blockage of the excavation hole due to the sliding of the piling stone of the rubble stone layer at the end of the spiral blade while the stirring blade is being compressed. Improved soft ground under the pebble layer Construction method.
のロッドの先端部と拡縮攪拌翼の近傍に２段設け、該２
段の内上方の噴射口は、下方に傾斜して固結液を噴射で
きるものであるオーガを使用することを特徴とする請求
項１記載の積石層下部の軟弱地盤を改良する工法。2. The high pressure consolidation liquid injection port is provided in two stages near the tip of the rod of the rock auger and near the expansion / contraction stirrer blade.
2. The method according to claim 1, wherein an auger capable of injecting the consolidation liquid by inclining downward is used as an injection port in an upper part of the step.
オーガであり、回転ロッドの先端に固結液噴射口とロッ
クビットを有し、その上部に拡縮自在な複数の攪拌翼
と、水平方向及び下方傾斜方向に液体を噴射する噴射口
と、更に上方のロッドには、該攪拌翼の縮翼時の外径よ
りもやや大きな外径であってそのピッチが掘削される積
石の平均的直径より小さい螺旋翼を、少なくとも改良作
業時に該ロッドが最下点まで嵌入された状態でのその捨
石層面より上方位置まで設けられていることを特徴とす
る積石層下部の軟弱地盤を改良するための装置。3. A rock auger capable of excavating a pile consisting of a rubble layer, having a condensed liquid injection port and a lock bit at the tip of a rotating rod, and a plurality of expandable and contractible stirring blades on an upper portion thereof. The injection port that injects the liquid in the direction and the downward inclination direction, and the rod further above has an outer diameter slightly larger than the outer diameter of the stirring blade at the time of contraction, and the average pitch of the stones to be excavated. A helical wing smaller than the target diameter is provided at least to a position above the rubble layer surface in a state where the rod is fitted to the lowest point at the time of the improvement work, and the soft ground at the lower part of the stone layer is improved. Equipment for doing.
cmの範囲内であることを特徴とする請求項３記載の積石
層下部の軟弱地盤を改良する装置。4. A pitch of the spiral wing is 15 cm to 50 cm.
4. The apparatus for improving soft ground under a piling layer according to claim 3, wherein the area is within a range of cm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9187190A JP3056700B2 (en) | 1997-06-30 | 1997-06-30 | Construction method and equipment for improving soft ground under the pile |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9187190A JP3056700B2 (en) | 1997-06-30 | 1997-06-30 | Construction method and equipment for improving soft ground under the pile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1121872A true JPH1121872A (en) | 1999-01-26 |
| JP3056700B2 JP3056700B2 (en) | 2000-06-26 |
Family
ID=16201688
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9187190A Expired - Lifetime JP3056700B2 (en) | 1997-06-30 | 1997-06-30 | Construction method and equipment for improving soft ground under the pile |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3056700B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013167139A (en) * | 2012-02-17 | 2013-08-29 | Tenox Corp | Soil improvement method and soil improving device |
| JP2017179756A (en) * | 2016-03-29 | 2017-10-05 | エポコラム機工株式会社 | Method and device for ground improvement |
| JP2021025200A (en) * | 2019-07-31 | 2021-02-22 | 旭化成建材株式会社 | Drilling device and column building method using drilling device |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101053436B1 (en) * | 2010-04-26 | 2011-08-02 | 조현준 | Improved stirring bit |
-
1997
- 1997-06-30 JP JP9187190A patent/JP3056700B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013167139A (en) * | 2012-02-17 | 2013-08-29 | Tenox Corp | Soil improvement method and soil improving device |
| JP2017179756A (en) * | 2016-03-29 | 2017-10-05 | エポコラム機工株式会社 | Method and device for ground improvement |
| JP2021025200A (en) * | 2019-07-31 | 2021-02-22 | 旭化成建材株式会社 | Drilling device and column building method using drilling device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3056700B2 (en) | 2000-06-26 |
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