JPH10266758A - Cut-off method for excavated hole mouth and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the effect of cut-off and work efficiency. SOLUTION: An intervening member 3 having a projection 3a mounting to a specific position of an excavated hole member formed by connecting a plurality of unit excavated hole members is connected in a detachable manner, and a hole is excavated with a boring machine by means of the excavated hole member. A mouth cut-off device 10 is pushed in by thrust of the excavated hole member through the projection 3a, and after the completion of pushing in, the intervening member 3 is replaced with the normal unit excavated hole members in a state to substantially close the mouth cut-off device 10 with the excavated hole member, and the hole is again excavated up to required depth.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、削孔口元止水方法
およびそのための装置に関し、さらに詳しくは被圧水下
における削孔の際に削孔口元から土砂および水等が噴出
するのを防止するために適した方法およびそのための装
置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of stopping water at a drilling hole and a device therefor, and more particularly, to preventing earth and sand, water, etc. from spouting from the drilling hole at the time of drilling under pressurized water. And a device therefor.

【０００２】[0002]

【従来の技術】アンカー工事においてはアンカーの建て
込みのために削孔機による削孔が行われる。また、トン
ネル掘削等の水平方向掘削の場合に切羽安定や透水性の
低減等を目的として、トンネル切羽面前方またはその周
辺を薬液注入によって地盤改良するために削孔機による
削孔がなされる。さらに、根切り工事において周辺の建
物への影響を無くすことを目的として、その土留め矢板
または土留め壁の背面部分を薬液注入によって地盤改良
するためにも削孔機による削孔がなされる。2. Description of the Related Art In anchor work, drilling is performed by a drilling machine to install an anchor. In addition, in the case of horizontal excavation such as tunnel excavation, a hole is drilled by a drilling machine in order to improve the ground in front of or around the tunnel face by chemical injection for the purpose of stabilizing the face and reducing water permeability. Further, in order to eliminate the influence on surrounding buildings in the excavation work, a drilling machine is also used to improve the ground of the backing sheet pile or the backside of the retaining wall by injecting a chemical solution.

【０００３】従来から、被圧水下すなわち地下水圧の影
響を受ける地盤において削孔を行った場合に、削孔口元
より水および土砂等が噴出するという問題が生じてい
た。さらに、かかる土砂等の噴出によって、対象地盤の
地態が悪化すること、既に注入されている隣接注入剤が
流出してしまうこと等の問題点を生じていた。[0003] Conventionally, there has been a problem in that, when drilling is performed under pressure to be applied, that is, in a ground affected by groundwater pressure, water, earth and sand, etc., are spouted from the drill hole opening. In addition, such eruption of earth and sand has caused problems such as deterioration of the ground condition of the target ground, and outflow of an already injected adjacent injection agent.

【０００４】本出願人は、特開平６−３１６９２１号公
報において、シートパイルや土留め壁等の構造物に削孔
口元を止水するための口元止水装置（以下、単に口元止
水装置ともいう）を設けることを提案した。[0004] The present applicant has disclosed in Japanese Patent Application Laid-Open No. Hei 6-316921 a mouth water stop device (hereinafter, simply referred to as a mouth water stop device) for stopping water from being drilled in a structure such as a sheet pile or a retaining wall. ) Was proposed.

【０００５】一方、従来のアンカー工事の場合における
止水態様例を次に説明する。図１６に示すように、シー
トパイル８０の所定位置に必要に応じて台座８１を取付
け、この台座８１の孔口８１ａに口元止水装置１００を
仮装着した後、台座８１の孔口８１ａに沿って段差を生
じさせないようにシートパイル８０の孔開けを行ってお
く。口元止水装置１００は、ケーシング９０（同図には
図示せず）が貫通される管状部１０１の後端に、これと
一体となって半径方向に張り出すフランジ部１０２を有
し、フランジ部１０２と鋼板１０４との間に止水ゴム１
０５を介在させて固定したもので、この止水ゴムがケー
シング９０の貫通状態においてその外周面に接して液密
状態に保持する構造である。On the other hand, an example of a water stopping mode in the case of a conventional anchor construction will be described below. As shown in FIG. 16, a pedestal 81 is attached to a predetermined position of the sheet pile 80 as necessary, and the mouth water stop device 100 is temporarily attached to the opening 81 a of the pedestal 81, and then along the opening 81 a of the pedestal 81. The sheet pile 80 is perforated so as not to cause a step. The mouth water stopping device 100 has a flange portion 102 which is integrally formed with a rear end of a tubular portion 101 through which a casing 90 (not shown in the drawing) penetrates, and which protrudes in a radial direction. Water-stopping rubber 1 between 102 and steel plate 104
The structure is such that the waterproof rubber is in contact with the outer peripheral surface of the casing 90 in a penetrating state and is maintained in a liquid-tight state.

【０００６】次に、図１７に示すように、外周面にフラ
ンジ部９１ａを有するフランジ付管状部材９１が先端に
装着されたケーシング９０を用い、フランジ付管状部材
９１の先端を口元止水装置１００に挿入し、フランジ付
管状部材９０のフランジ部９０ａを口元止水装置１００
の鋼板１０４に引掛けた状態で、図示しないパーカッシ
ョンの衝撃力をケーシング９０に与える。この衝撃力に
よりフランジ部９１ａを介して口元止水装置１００を台
座８１に押し込まれる。[0006] Next, as shown in FIG. 17, a casing 90 having a flanged tubular member 91 having a flange portion 91a on the outer peripheral surface is attached to the tip of the casing 90. And the flange portion 90a of the flanged tubular member 90 is
While being hooked on the steel plate 104, an impact force of a percussion (not shown) is applied to the casing 90. The water stop device 100 at the mouth is pushed into the pedestal 81 via the flange portion 91a by this impact force.

【０００７】図１８に示すように、口元止水装置１００
が完全に押し込まれ装着されたならば、図１９に示すよ
うにケーシング９０を引き抜きく。そして、ケーシング
９０からフランジ付管状部材９１を取り外し、代わりに
先端ビットを装着して所望の深度まで削孔を行う（図示
せず）。以降、公知の施工方法と同様にグラウト注入お
よび引張材の建て込み等を行ってアンカーを造成する。[0007] As shown in FIG.
Is completely pushed and attached, the casing 90 is pulled out as shown in FIG. Then, the flanged tubular member 91 is removed from the casing 90, and a tip bit is attached instead, and a hole is drilled to a desired depth (not shown). Thereafter, grout is injected and a tensile member is laid in the same manner as in a known construction method to form an anchor.

【０００８】[0008]

【発明が解決しようとする課題】しかしながら、かかる
従来の削孔口元止水方法においては、止水体の押し込み
完了後、削孔開始までの間における口元の止水が不可能
であった。具体的には、図１９に示すように、口元止水
装置１００の装着後にケーシング９０を引き抜くと、シ
ートパイル８０の背面近傍の被圧水および土砂が口元止
水装置１００を介して一気に噴出していた。このため、
シートパイル等の構造物背面近傍の地態が悪化し、地盤
改良の本来の目的を良好に達成できなかった。However, in such a conventional method for stopping water at a drilling hole, it is impossible to stop water at the mouth from completion of pushing of the water stopping body to the start of drilling. Specifically, as shown in FIG. 19, when the casing 90 is pulled out after the mouth water stop device 100 is mounted, the pressurized water and the earth and sand near the back of the sheet pile 80 squirt through the mouth water stop device 100 at once. I was For this reason,
The ground condition near the back of the structure such as the sheet pile deteriorated, and the original purpose of the ground improvement could not be achieved well.

【０００９】また、従来の口元止水装置においては、シ
ール材（図示の例では止水ゴム）とケーシングとの間に
隙間を生じ易く、その止水効果は十分なものでなかっ
た。Further, in the conventional mouth water stopping device, a gap is easily formed between the sealing material (water stopping rubber in the illustrated example) and the casing, and the water stopping effect is not sufficient.

【００１０】一方、止水効果を向上せしめる応急的な対
策として、削孔部における構造物背面近傍の領域を瞬結
材を用いて改良し、当該領域の被圧水および土砂の流出
を防ぐ方法を採用していた。しかし、この方法は、作業
労力および作業時間等の観点から好ましい方法ではな
い。On the other hand, as an emergency measure to improve the water stopping effect, a method of improving the area near the back surface of the structure in the drilled portion by using an instantaneous binder to prevent the outflow of pressurized water and earth and sand in the area. Was adopted. However, this method is not a preferable method from the viewpoint of work labor and work time.

【００１１】そこで、本発明の主たる課題は、止水性お
よび作業性に優れる削孔口元止水方法およびそのための
装置を提案することにある。Therefore, a main object of the present invention is to propose a method for stopping water at a drilling hole excellent in water stopping property and workability, and an apparatus therefor.

【００１２】[0012]

【課題を解決するための手段】上記課題を達成した本発
明は、削孔機により削孔部材に回転および推進力を与え
ながら対象地盤を削孔する場合において、前記削孔部材
と地盤の削孔口元との間を止水体により封止して止水を
図るに際して、前記削孔部材の長手方向途中にまたは削
孔部材の長手方向途中に介在させた介在部材に張出部を
設け、前記削孔機による削孔部材の推進力により、前記
張出部を介して前記止水体を地盤内に押し込むことを特
徴とする削孔口元止水方法である。According to the present invention, which has achieved the above objects, the present invention provides a method for drilling a target ground while applying rotation and propulsion to the drilling member using a drilling machine. When sealing the gap between the hole and the mouth with a water blocking body to achieve water stopping, a projecting portion is provided on an intervening member interposed in the longitudinal direction of the drilling member or in the longitudinal direction of the drilling member, A method for stopping water at a drilling hole base, wherein the water stopping body is pushed into the ground through the overhang portion by a propulsive force of a drilling member by a drilling machine.

【００１３】この場合、前記削孔部材の長手方向途中に
張出部材を着脱自在に設け、前記止水体の地盤内への押
し込みに先立って前記張出部材を前記削孔部材に固定し
て前記張出部として用い、前記止水体の地盤内への押し
込みが完了した後に、前記張出部材を取り外すのは好ま
しい。In this case, a projecting member is detachably provided in the middle of the drilling member in the longitudinal direction, and the projecting member is fixed to the drilling member prior to pushing the water stopping body into the ground. It is preferable to use the projecting member as a projecting portion and remove the projecting member after the pushing of the water stopping body into the ground is completed.

【００１４】また、前記介在部材を前記削孔部材に着脱
自在とし、前記止水体の地盤内への押し込みに先立って
前記介在部材を前記削孔部材に連結し、前記止水体の地
盤内への押し込みが完了した後に、前記介在部材を取り
外すのも好ましい。Further, the interposed member is made detachable from the drilling member, and the interposed member is connected to the drilling member prior to pushing the water stopping body into the ground, so that the water stopping body is inserted into the ground. It is also preferable to remove the intervening member after the pushing is completed.

【００１５】これらの発明において、前記削孔部材はケ
ーシングからなるのも好ましい。In these inventions, it is preferable that the drilling member is formed of a casing.

【００１６】本発明では、削孔機により削孔を行う場合
の削孔部材の推進力により、張出部を介して止水体を地
盤内に押し込むことによって、削孔と併行してすなわち
削孔口元を削孔部材により塞いだ状態で止水体の押し込
みがなされる。このため、本発明では、前述の従来例の
ような削孔口元からの水および土砂の噴出が実質的にな
い。In the present invention, the water stopping body is pushed into the ground through the overhang by the propulsive force of the drilling member when drilling by the drilling machine, so that the drilling is performed in parallel with the drilling, that is, the drilling is performed. The water stop is pushed in while the mouth is closed by the drilling member. For this reason, in the present invention, water and earth and sand are not substantially spouted from the drill hole as in the conventional example described above.

【００１７】一方、請求項５に記載の発明は、削孔機に
より削孔部材に回転および推進力を与えながら対象地盤
を削孔する場合において、前記削孔部材と地盤の削孔口
元との間を封止して止水を図る削孔口元止水装置であっ
て、前記削孔部材が貫通される管状部と、これと一体と
なって半径方向に張り出すフランジ部とを有し、前記装
置の長手方向に離間する少なくとも２か所において、装
置と一体となり前記削孔部材の外周面に接するシール材
を備えることを特徴とする口元止水装置である。According to a fifth aspect of the present invention, when drilling a target ground while applying rotation and propulsive force to a drilling member by a drilling machine, the drilling member and the ground hole opening of the ground are drilled. A drill hole mouth water stop device that seals the gap to stop water, comprising a tubular portion through which the drilling member is penetrated, and a flange portion that extends integrally with the tubular portion in the radial direction, A mouth water shutoff device comprising a seal member integrated with the device and in contact with the outer peripheral surface of the drilling member at at least two places separated in the longitudinal direction of the device.

【００１８】請求項６に記載の発明は、削孔機により削
孔部材に回転および推進力を与えながら対象地盤を削孔
する場合において、前記削孔部材と地盤の削孔口元との
間を封止して止水を図る削孔口元止水装置であって、前
記削孔部材が貫通される管状部と、これと一体となって
半径方向に張り出すフランジ部とを有し、前記装置の長
手方向に離間する少なくとも２か所において、装置と一
体となり前記削孔部材の外周面に接するシール材を備
え、さらに、前記管状部内と前記フランジ部外面とを連
通する排水通路が設けられていることを特徴とする削孔
口元止水装置である。According to a sixth aspect of the present invention, when drilling a target ground while applying rotation and propulsion to the drilling member by the drilling machine, the gap between the drilling member and the base of the drilling hole of the ground is provided. A drilling hole water stop device for sealing and stopping water, comprising a tubular portion through which the drilling member penetrates, and a flange portion integrally extending with the tubular portion and extending radially, At least two locations spaced apart in the longitudinal direction of the drilling device are provided with a sealing material integral with the device and in contact with the outer peripheral surface of the drilling member, and further provided with a drain passage communicating between the inside of the tubular portion and the outer surface of the flange portion. This is a water stop device at the base of the drilling hole.

【００１９】これら本発明の口元止水装置は、その長手
方向に離間する少なくとも２か所において削孔部材の外
周面に接するシール材を備えるため、従来のものに比べ
て止水性に優れるものである。Since the mouth water stopping device of the present invention is provided with a sealing material that is in contact with the outer peripheral surface of the drilling member at least at two locations separated in the longitudinal direction, the water stopping device is superior in water stopping performance to the conventional one. is there.

【００２０】[0020]

【発明の実施の形態】以下、具体例に基づき本発明につ
いて詳述する。図１は、本発明にいう張出部を設けた削
孔部材の具体例を示しており、単位削孔部材１ａ，１ａ
…を複数連結して構成された削孔部材１Ａに、削孔のた
めの先端ビット２が装着される一方、所定の位置（詳し
くは後述するが、図示の例では最先端の単位ケーシング
の次とされている）に、張出部３ａを有する介在部材３
が連結されたものである。この介在部材３は、少なくと
もその先後の単位削孔部材１ａ，１ａに対して着脱自在
とされるのが好ましい。図示の張出部３ａは、介在部材
３の外周に連続して半径方向に張出すようにして、いわ
ゆるフランジ状に形成したものである。もちろん、本発
明における張出部は、介在部材の外周に連続して形成す
る必要は必ずしもなく、介在部材の外周に一つの又は複
数の張出部を不連続に設けることもできる。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on specific examples. FIG. 1 shows a specific example of a drilling member provided with an overhang portion according to the present invention, and includes unit drilling members 1a, 1a.
Are attached to the drilling member 1A formed by connecting a plurality of drill bits, while the drill bit 1 is mounted at a predetermined position (details will be described later, but in the example shown in FIG. Intervening member 3 having an overhang 3a
Are concatenated. It is preferable that the intervening member 3 is detachably attached to at least the preceding and following unit drilling members 1a, 1a. The projecting portion 3a shown is formed in a so-called flange shape so as to continuously project in the radial direction on the outer periphery of the interposition member 3. Of course, the overhang in the present invention does not necessarily need to be formed continuously on the outer periphery of the intervening member, and one or a plurality of overhangs may be provided discontinuously on the outer periphery of the intervening member.

【００２１】また、図示の例では張出部３ａの削孔部材
１Ａ軸方向の耐力を向上させるべく、介在部材３の外周
面に張出部３ａの背面３ｃから長手方向に延在してフラ
ンジ部３ａを支持する支持凸部３ｂ，３ｂが設けられて
いる。尚、介在部材３の連結位置は、もちろん３本目あ
るいはそれ以降であっても良い。In the example shown in the drawing, in order to improve the axial strength of the projecting portion 3a in the axial direction of the drilling member 1A, a flange extending in the longitudinal direction from the back surface 3c of the projecting portion 3a is provided on the outer peripheral surface of the interposed member 3. Support projections 3b, 3b for supporting the portion 3a are provided. The connecting position of the intervening member 3 may be the third or later.

【００２２】他の例としては、図２に示すように、張出
部４ａを有する張出部材４を削孔部材１Ｂの所定の位置
（後述する）に対して着脱自在に設けたものが提案され
る。As another example, as shown in FIG. 2, it is proposed that an overhanging member 4 having an overhanging portion 4a is detachably provided at a predetermined position (described later) of the drilling member 1B. Is done.

【００２３】この張出部材４は、図３（ａ），（ｂ），
（ｃ）に示すように、管状部４ｅ，４ｅの一端において
その外周に連続して半径方向に張り出すようにしていわ
ゆる管フランジ状に形成したものであり、その軸心につ
いて対称形の２個の部材４Ａ，４Ｂに分解可能とされ、
管状部４ｅ，４ｅの内面は削孔部材１Ｂ外面に接するサ
イズ・形状とされる。The overhang member 4 is shown in FIGS. 3 (a), (b),
As shown in FIG. 2C, two end portions of the tubular portions 4e, 4e are formed in a so-called tube flange shape so as to protrude in the radial direction continuously to the outer periphery thereof. It can be disassembled into members 4A and 4B,
The inner surfaces of the tubular portions 4e, 4e are sized and shaped to be in contact with the outer surface of the drilling member 1B.

【００２４】図示の張出部材４には、図１に示す例と同
様に、その管状部４ｅの外周面に張出部部４ａの背面４
ｆから管状部４ｅ軸方向に延在して張出部４ａを支持す
る支持凸部４ｂ，４ｂおよび４ｃ，４ｃが設けられてい
る。但し本例における支持凸部４ｂ，４ｂおよび４ｃ，
４ｃは、分解状態の部材４Ａ，４Ｂの各々についてその
対向面を構成するように設けられており、これら対向す
る支持凸部４ｂ，４ｂおよび４ｃ，４ｃがボルト（図示
せず）で連結される。４ｄ，４ｄ…はボルト挿通孔であ
る。したがって、これら分解状態の部材４Ａ，４Ｂを削
孔部材１Ｂを挟持するように連結することによって、削
孔部材１Ｂ外周面に張出部材４が取り付けられ、逆に当
該連結を解くことにより削孔部材１Ｂからの張出部材４
の取り外しがなされる。尚、図示の例とは異なり、張出
部材を２つ以状の部材に分解可能に構成しても良い。As shown in FIG. 1, the projecting member 4 has a rear surface 4a of the projecting portion 4a on the outer peripheral surface of the tubular portion 4e.
Support projections 4b, 4b and 4c, 4c that extend in the axial direction from f and support the overhang 4a are provided. However, the support projections 4b, 4b and 4c,
4c is provided so that each of the members 4A and 4B in the disassembled state forms an opposing surface, and the opposing support projections 4b and 4b and 4c and 4c are connected by bolts (not shown). . 4d, 4d... Are bolt insertion holes. Therefore, by connecting these disassembled members 4A and 4B so as to sandwich the drilling member 1B, the projecting member 4 is attached to the outer peripheral surface of the drilling member 1B. Overhang member 4 from member 1B
Is removed. Note that, unlike the illustrated example, the overhanging member may be configured to be disassembled into two or more members.

【００２５】さらに、図４に示すように、張出部５ａを
設けた介在部材５の先端側に、着脱自在の張出部材４を
設けた複数の単位削孔部材１ｃ，１ｃ…よりなる削孔部
材１Ｃも考えられる。５ｂは張出部５ａを支持するため
の支持凸部である。Further, as shown in FIG. 4, a plurality of unit drilling members 1c, 1c,... A hole member 1C is also conceivable. Reference numeral 5b denotes a supporting projection for supporting the overhanging portion 5a.

【００２６】図１〜図４においては、削孔部材は単位削
孔部材を複数連結したものとして図示したが、もちろん
単なる１本の削孔部材であっても良い。また、削孔部材
はケーシングであっても良い。In FIGS. 1 to 4, the drilling member is shown as a plurality of unit drilling members connected to each other. However, it is needless to say that a single drilling member may be used. Further, the drilling member may be a casing.

【００２７】次に、本発明の口元止水装置の具体例につ
いて説明する。尚、下記に示す口元止水装置は、後述す
る本発明に係る口元止水方法の他、従来の口元止水方法
に用いることもできる。図５および図６に示す口元止水
装置（以下、第１具体例という）１０は、削孔部材１が
遊びをもって貫通される管状部１１ａと、その後端（図
中上側）においてその外周に連続して半径方向に張り出
すフランジ部１１ｂとを有する内側部材１１が、これと
略同形でサイズの大きい外側部材１２に間隙をもって内
装され、この間隙に前記内側部材と略同形の内側シール
材１３が挟まれて当該間隙を液密状態とするとともに、
内側シール材１３の管状先端１３ａが内側部材１１の先
端１１ｃよりも先端側（図中下側）において削孔部材１
外周面に接するように延在し、内側部材１１の管状部１
１ａ内面と削孔部材１外面との間隙ｓ１を液密状態とし
たものである。Next, a specific example of the mouth water stopping device of the present invention will be described. The mouth water stopping device shown below can be used for a conventional mouth water stopping method in addition to the mouth water stopping method according to the present invention described later. A mouth water stoppage device (hereinafter, referred to as a first specific example) 10 shown in FIGS. 5 and 6 has a tubular portion 11a through which a drilling member 1 penetrates with play, and a rear end (upper side in the drawings) continuous with an outer periphery thereof. And an inner member 11 having a flange portion 11b projecting in the radial direction is provided with a gap in an outer member 12 having a substantially same shape and a large size, and an inner sealing material 13 having substantially the same shape as the inner member is provided in the gap. While being sandwiched, the gap is made liquid-tight,
The drilling member 1 has a tubular tip 13a of the inner sealing member 13 on the tip side (lower side in the figure) of the tip 11c of the inner member 11.
The tubular portion 1 of the inner member 11 extends so as to be in contact with the outer peripheral surface.
The gap s1 between the inner surface 1a and the outer surface of the hole-piercing member 1 is in a liquid-tight state.

【００２８】さらに、間隙ｓ１について内側部材１１の
後端側においても液密状態を保持するべく、従来の口元
止水装置と同様にシール材１４が配されている。すなわ
ち、フランジ部１１ｂと板状部材１５との間に、外側シ
ール材１４を挟んで固定している。貫通孔１５ａは削孔
部材１が遊びをもって貫通される程度の孔径とされ、貫
通孔１４ａは削孔部材１外周面に接して液密状態を保持
する程度の孔径とされる。Further, in order to maintain a liquid-tight state at the rear end side of the inner member 11 with respect to the gap s1, a sealing member 14 is provided similarly to the conventional mouth water shutoff device. That is, the outer sealing member 14 is fixed between the flange portion 11b and the plate member 15. The through-hole 15a has a diameter such that the drilling member 1 penetrates with play, and the through-hole 14a has a diameter that is in contact with the outer peripheral surface of the drilling member 1 and maintains a liquid-tight state.

【００２９】また、内側部材１１のフランジ部１１ｂ、
外側部材１２のフランジ部１２ｂ、内側シール材１３の
フランジ部１３ｂ、外側シール材１４および板状部材１
５を貫通するボルト挿通孔１８，１８…が設けられ、こ
れら内側部材１１、外側部材１２、内側シール材１３、
外側シール材１４および板状部材１５の全てがボルト１
６，１６…およびナット１７，１７…により固定され
る。Also, the flange portion 11b of the inner member 11,
Flange portion 12b of outer member 12, flange portion 13b of inner seal member 13, outer seal member 14, and plate member 1
Are provided through the inner member 11, the outer member 12, the inner seal material 13,
All of the outer sealing material 14 and the plate-like member 15 are bolts 1
6 and 16 and nuts 17 and 17.

【００３０】図示の例では、内側シール材１３の管状先
端１３ａは内側部材１１の先端１１ｃからさらに先端側
に向かってその径を縮小しつつ削孔部材１外周面に当接
するよう形成されており、間隙ｓ１における装置口元方
向への逆流を防止する逆止弁をなす。この逆止弁によっ
て従来の口元止水装置に比べて格段に優れた止水効果を
発揮する。In the illustrated example, the tubular tip 13a of the inner sealing member 13 is formed so as to abut on the outer peripheral surface of the drilling member 1 while reducing its diameter from the tip 11c of the inner member 11 further toward the tip. And a check valve for preventing backflow in the gap s1 in the direction toward the mouth of the apparatus. With this check valve, a water stopping effect that is significantly superior to that of a conventional mouth water stopping device is exhibited.

【００３１】一方、図７および図８に示す口元止水装置
２０（以下、第２具体例という）は、削孔時の削孔水・
湧水と掘削土の細粒分とが混じり合った泥水の排出等に
用いる排出路を設けたものである。詳しくは同図に示す
よに、前述の第１具体例と略同形状の外側部材２２の内
部に、その管状部２２ａからそのフランジ部２２ｂ端部
まで延在する間隙ｓ２が設けられる。この間隙ｓ２は、
内側シール材２３の先端２３ａよりも先端側における外
側部材内壁２２ｃに設けられた連通孔２２ｄにより外側
部材２２内面と削孔部材１外面との間隙ｓ３に連通する
一方で、外側部材２２のフランジ部２２ｂ端部におい
て、その内側シール材側の壁、内側シール材２３のフラ
ンジ部２３ｂ、内側部材２１のフランジ部２１ｂ、外側
シール材２４および板状部材２５を貫通する連通孔２９
により板状部材２５外面に連通し、間隙ｓ３と板状部材
２５外面装置２０外面とを連通する排出路が構成され
る。On the other hand, the mouth water stopping device 20 (hereinafter, referred to as a second specific example) shown in FIGS.
A drainage path is provided for discharging muddy water in which spring water and fine-grained soil are mixed. As shown in detail in the figure, a gap s2 extending from the tubular portion 22a to the end of the flange portion 22b is provided inside the outer member 22 having substantially the same shape as that of the first specific example. This gap s2 is
While communicating with a gap s3 between the inner surface of the outer member 22 and the outer surface of the drilling member 1 through a communication hole 22d formed in the outer member inner wall 22c on the distal end side of the distal end 23a of the inner seal member 23, the flange portion of the outer member 22 is formed. A communication hole 29 penetrating through the wall on the inner seal material side, the flange portion 23b of the inner seal material 23, the flange portion 21b of the inner member 21, the outer seal material 24, and the plate-like member 25 at the end portion 22b.
Thus, a discharge path communicating with the outer surface of the plate-shaped member 25 and communicating the gap s3 with the outer surface of the plate-shaped member 25 outer surface device 20 is formed.

【００３２】図示の例では、内側シール材２３の管状先
端２３ａが、内側部材２１の先端２１ｃからさらに先端
側に向かってその径を縮小しつつ削孔部材１外周面に接
し、この当接部位ｘからさらに先端側に径を拡大しつつ
延在し外側部材内壁２２ｃに固定されて、管状部２１ａ
内面と削孔部材１外面との間隙ｓ３に対して内側部材２
１の先端側において液密状態を保持する構造とされてい
る。もちろん本第２具体例において第１具体例と同様の
内側シール材を設けても良い。In the illustrated example, the tubular tip 23a of the inner seal member 23 comes into contact with the outer peripheral surface of the drilling member 1 while reducing its diameter from the tip 21c of the inner member 21 further toward the tip side. x extending further from the distal end to the distal end side while being fixed to the outer member inner wall 22c, the tubular portion 21a
For the gap s3 between the inner surface and the outer surface of the drilling member 1, the inner member 2
1 is configured to maintain a liquid-tight state on the tip side. Of course, in the second specific example, an inner sealing material similar to that of the first specific example may be provided.

【００３３】この第２具体例において、その他の構造に
ついては、例えば間隙ｓ４に対して内側部材２１の後端
側においても液密状態を保持するべく、内側部材２１の
フランジ部２１ｂと板状部材２５との間に外側シール材
２４を挟んで固定している点等は、前述の第１具体例と
同様であるから敢えて説明を省略する。尚、同図中、２
４ａは外側シール材の貫通孔、２５ａは板状部材の貫通
孔、２６はボルト、２７はナット、２８はボルト挿通孔
である。In the second specific example, the other structure is such that the flange portion 21b of the inner member 21 and the plate-like member 21 are kept liquid-tight at the rear end side of the inner member 21 with respect to the gap s4, for example. The point that the outer seal member 24 is interposed and fixed between the first example and the second example is the same as in the first specific example described above, and therefore the description thereof is omitted. Incidentally, in FIG.
4a is a through hole of the outer sealing material, 25a is a through hole of the plate member, 26 is a bolt, 27 is a nut, and 28 is a bolt insertion hole.

【００３４】さて、次にアンカー工法の削孔例を引き、
前述の削孔部材および口元止水装置を用いた削孔口元止
水方法について説明するが、本発明はこれに限定される
ものではなく、その他の削孔にも好適に用いることがで
きる。先ず、図９に示すように、シートパイル４０（土
留め矢板等の他の構造物でも同様である。）の所定位置
に必要に応じて台座４１を取付け、台座４１の孔口４１
ａに前述の第１具体例の口元止水装置口１０を仮装着し
た後、この台座４１の孔口４１ａに沿って段差を生じさ
せないようにシートパイル４０の孔開けを行う。次に、
図１０に示すように、複数の単位ケーシング５０ａ，５
０ａ…が連結され、先端ビット２が装着され、かつ所定
の位置（詳しくは後述するが、図示の例では先端ケーシ
ングの次とされている）に張出部３ａを有する介在部材
３が着脱自在に連結されたケーシング５０を、口元止水
装置１０に挿通させて削孔を行う。この削孔において、
張出部３ａが口元止水装置１０の板状部材１５に引掛か
り、削孔の推進力（図中、矢印で示す）が張出部３ａを
介して口元止水装置１０に与えられて、削孔と併行して
口元止水装置１０が台座４１の孔口４１ａに押し込まれ
る。Next, a drilling example of the anchor method will be described.
A method for stopping water at the mouth of a hole using the above-described hole-piercing member and water stopping device at the mouth will be described. However, the present invention is not limited to this, and can be suitably used for other holes. First, as shown in FIG. 9, a pedestal 41 is attached to a predetermined position of a sheet pile 40 (the same applies to other structures such as earth retaining sheet piles) as necessary.
After the mouth water stop device port 10 of the above-described first specific example is temporarily attached to a, a hole is formed in the sheet pile 40 so that a step does not occur along the hole 41 a of the pedestal 41. next,
As shown in FIG. 10, a plurality of unit casings 50a, 50
0a... Are connected, the tip bit 2 is mounted, and the interposition member 3 having the overhang portion 3a at a predetermined position (to be described in detail later, but following the tip casing in the illustrated example) is detachable. Is drilled by inserting the casing 50 connected to the water stop device 10 at the mouth. In this drilling,
The overhang portion 3a is hooked on the plate-like member 15 of the mouth water stop device 10, and the propulsive force of the drilling (indicated by an arrow in the drawing) is given to the mouth water stop device 10 via the overhang portion 3a. The mouth water stop device 10 is pushed into the hole 41 a of the base 41 in parallel with the drilling.

【００３５】図１１に示すように口元止水装置１０が台
座４１に完全に押し込まれたならば、図１３に示すよう
に介在部材３を取り外す。この際に、図１２に示すよう
にケーシング５０が内側シール材１３の先端１３ａの開
口を塞いだ状態を維持できる範囲（図１３参照）であれ
ば、後述する介在部材３の取り外しおよび単位ケーシン
グの連結を容易にするために、必要に応じてケーシング
５０を弱冠後退させることもできる。When the mouth water stopping device 10 is completely pushed into the base 41 as shown in FIG. 11, the intervening member 3 is removed as shown in FIG. At this time, as shown in FIG. 12, if the casing 50 can maintain the state in which the opening of the distal end 13a of the inner seal material 13 is closed (see FIG. 13), the removal of the intervening member 3 described later and the In order to facilitate the connection, the casing 50 can be retracted slightly if necessary.

【００３６】続いて図１３に示すように、取り外した介
在部材３の代わりに通常の単位ケーシング５０ａを代わ
りに取り付けるか、あるいは介在部材３の先後の単位ケ
ーシング５０ａ，５０ａを連結して、図１４に示すよう
に通常のケーシング５０Ａとし、これにより所望の深度
までケーシング削孔を行う。以降、図示しないが、公知
の施工方法に従ってグラウト材注入、引張材の建て込み
等を行ってアンカーを造成する。Then, as shown in FIG. 13, a normal unit casing 50a is attached instead of the removed intervening member 3, or the unit casings 50a, 50a at the front and rear of the intervening member 3 are connected to each other, as shown in FIG. As shown in Fig. 7, a normal casing 50A is used, and the casing is bored to a desired depth. Thereafter, although not shown, the grout material is injected according to a known construction method, a tensile material is erected, and the like, thereby forming an anchor.

【００３７】図１３に示すように、介在部材３の取り外
し時においてもケーシング５０により口元止水装置１０
が実質的に塞いだ状態とされるため、この際にシートパ
イル４０等の構造物背面近傍に抑圧されていた水および
土砂が口元止水装置１０を介して噴出することがない。
また、本例では、削孔と口元止水装置の装着を併行して
行うことができるため作業能率の向上も図られる。さら
に、本例で用いた口元止水装置１０は、従来例と同様の
外側シール材１４に加えて内側シール材１３により構成
される逆止弁を備えており、削孔中あるいは介在部材３
の取り外しの際の止水効果に大変優れるものである。As shown in FIG. 13, even when the intervening member 3 is removed, the casing 50 prevents
Is substantially closed, so that water and earth and sand that have been suppressed in the vicinity of the back surface of the structure such as the sheet pile 40 do not blow out through the mouth water stop device 10 at this time.
Further, in this example, the drilling and the installation of the mouth water stop device can be performed simultaneously, so that the work efficiency is improved. Further, the mouth water stopping device 10 used in the present example is provided with a check valve composed of the inner sealing material 13 in addition to the outer sealing material 14 similar to the conventional example, and is used for drilling or for the interposition member 3.
It is very excellent in the water stopping effect at the time of removing.

【００３８】一方、上記例における施工手順は、介在部
材５の先端側に、着脱自在の張出部材４を取付けたケー
シング（図４参照）を用いる場合でも基本的に同様であ
るのでここでは敢えて説明しない。但し、この場合に
は、介在部材３および張出部材４を介して削孔の推進力
が口元止水装置に与えられる。On the other hand, the construction procedure in the above example is basically the same even when a casing (see FIG. 4) in which the detachable overhanging member 4 is attached to the distal end side of the interposition member 5 is basically the same, so that it is dared here. No explanation. However, in this case, the driving force of the drilling is applied to the mouth water stop device via the intervening member 3 and the overhanging member 4.

【００３９】これに対して、張出部４ａを有する張出部
材４を着脱自在に取り付けたケーシングを用いる場合に
は、図示しないが、削孔の推進力は張出部材４の張出部
４ａを介して口元止水装置に与えられて、削孔と併行し
て口元止水装置が台座に押し込まれる。口元止水装置１
０が台座４１に完全に押し込まれたならば、図１５に示
すように、そのままの状態で張出部材４を分解して取り
外す。ケーシング５１（図示の例では単位ケーシング５
１ａ，５１ａ…が複数連結されたものである）から張出
部材４を取り外した後は、そのまま所望の深度まで削孔
を行う。その他は上記例と同様である。On the other hand, in the case where a casing to which the overhanging member 4 having the overhanging portion 4a is detachably attached is used, although not shown, the propulsive force of the drilling is applied to the overhanging portion 4a of the overhanging member 4. And the water stop device is pushed into the base along with the drilling. Mouth water stop device 1
When 0 is completely pushed into the pedestal 41, the overhanging member 4 is disassembled and removed as it is, as shown in FIG. Casing 51 (in the example shown, unit casing 5
1a, 51a... Are connected to each other), and after the overhanging member 4 is removed, drilling is performed to a desired depth as it is. Others are the same as the above example.

【００４０】このように、張出部材４は、通常用いられ
るケーシング５１に対して着脱自在に取付けられている
ので、必要に応じて張出部材４を分解して取り外すだけ
でケーシングの連結等の手間の掛かる作業を必要とせず
に簡単に通常のケーシング５１となり、ケーシング５１
を後退させる必要は実質的には無く、後退させるとして
も、その後退量は極僅かで済むため、作業能率が非常に
高いものとなる。As described above, since the projecting member 4 is detachably attached to the casing 51 which is normally used, if necessary, the projecting member 4 can be disassembled and removed to simply connect the casing. The ordinary casing 51 can be easily obtained without requiring any troublesome work.
There is substantially no need to retract, and even if it is retracted, the amount of retraction is extremely small, and the work efficiency is extremely high.

【００４１】ここに、以上の説明から明らかなように、
介在部材の連結位置または張出部材の取り付け位置につ
いて所定の位置とは、介在部材または張出部材の取り外
しの際に削孔部材が口元止水装置を実質的に塞いだ状態
となる位置をいう。Here, as is clear from the above description,
The predetermined position with respect to the connection position of the interposition member or the attachment position of the overhang member refers to a position at which the drilling member substantially closes the water stop device at the time of removal of the interposition member or the overhang member. .

【００４２】すなわち、例えば上記介在部材を用いる場
合には、介在部材３の取り外しの際に、少なくともケー
シング５０が外側シール材１４の貫通孔１４ａを塞いだ
状態、好ましくは図１３に示すようにケーシング５０が
内側シール材１３の先端１３ａの開口を塞いだ状態とな
る位置であり、図示のように先端ケーシング１ａの次に
連結する必要は必ずしも無い。That is, for example, when the intervening member is used, when the intervening member 3 is removed, at least the casing 50 closes the through hole 14a of the outer seal member 14, preferably, as shown in FIG. Reference numeral 50 denotes a position where the opening of the distal end 13a of the inner seal material 13 is closed, and it is not always necessary to connect the distal end casing 1a next to the distal end casing 1a as shown in the figure.

【００４３】他方、上記例において、前述の排出路を有
する口元止水装置２０（図７参照）を用いることもで
き、その場合には上記例と同様の止水効果が発揮される
とともに排出路を介して削孔部材削孔時の削孔水・湧水
と掘削土の細粒分とが混じり合った泥水等を排出させる
ことができる。また、上記例において、従来の口元止水
装置（図１５等参照）を用いることもできる。この場合
には、口元止水装置自体による止水効果の向上はないも
のの、前述のように、ケーシングが口元止水装置を実質
的に塞いだ状態で介在部材や張出部材等を取り外すこと
ができるため、従来方法に比べるならば止水効果に優れ
たものとなる。On the other hand, in the above example, the mouth water stopping device 20 having the above-mentioned discharge path (see FIG. 7) can also be used. Through this, it is possible to discharge muddy water or the like in which drilling water / spring water at the time of drilling a drilling member and fine particles of excavated soil are mixed. In the above example, a conventional mouth water shutoff device (see FIG. 15 and the like) can also be used. In this case, although there is no improvement in the water stopping effect of the mouth water stop device itself, as described above, it is possible to remove the interposed member or the overhang member while the casing substantially closes the mouth water stop device. Therefore, the water stopping effect is superior to that of the conventional method.

【００４４】[0044]

【発明の効果】以上のとおり、本発明によれば、止水効
果が高く、かつ作業性に優れる削孔口元止水方法および
そのための装置となる。As described above, according to the present invention, there is provided a method for stopping water at a drilling hole having a high water stopping effect and excellent workability, and an apparatus therefor.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明に係る削孔部材の概略図である。FIG. 1 is a schematic view of a drilling member according to the present invention.

【図２】本発明に係る削孔部材の他の態様を示す概略図
である。FIG. 2 is a schematic view showing another embodiment of a drilling member according to the present invention.

【図３】張出部材を概略的に示す（ａ）正面図、（ｂ）
分解状態の右側面図、および（ｃ）分解部材の斜視図で
ある。3A is a front view schematically showing the overhang member, and FIG.
It is a right side view of an exploded state, and (c) is a perspective view of an exploded member.

【図４】本発明に係る削孔部材のさらに他の態様を示す
概略図である。FIG. 4 is a schematic view showing still another embodiment of the drilling member according to the present invention.

【図５】本発明に係る口元止水装置の第１具体例を概略
的に示す縦断面図である。FIG. 5 is a longitudinal sectional view schematically showing a first specific example of the mouth water stopping device according to the present invention.

【図６】その上面図である。FIG. 6 is a top view thereof.

【図７】本発明に係る口元止水装置の第２具体例を概略
的に示す縦断面図である。FIG. 7 is a longitudinal sectional view schematically showing a second specific example of the mouth water stopping device according to the present invention.

【図８】その上面図である。FIG. 8 is a top view thereof.

【図９】口元止水装置の台座への仮装着状態を概略的に
示す縦断面図である。FIG. 9 is a longitudinal sectional view schematically showing a temporary installation state of the mouth water stopping device on a base.

【図１０】口元止水装置の台座への装着過程を概略的に
示す縦断面図である。FIG. 10 is a longitudinal sectional view schematically showing a process of mounting the mouth water stopping device on a base.

【図１１】口元止水装置の台座への装着完了状態を概略
的に示す縦断面図である。FIG. 11 is a longitudinal sectional view schematically showing a state in which the mouth water stop device is completely mounted on the base.

【図１２】介在部材取り外しのためのケーシング引抜き
状態を概略的に示す縦断面図である。FIG. 12 is a longitudinal sectional view schematically showing a casing withdrawn state for removing an intervening member.

【図１３】介在部材の単位ケーシングへの交換を概略的
に示す縦断面図である。FIG. 13 is a vertical sectional view schematically showing replacement of an interposition member with a unit casing.

【図１４】通常のケーシングによる掘削状態を概略的に
示す縦断面図である。FIG. 14 is a longitudinal sectional view schematically showing a state of excavation by a normal casing.

【図１５】張出部材の取り外しを概略的に示す縦断面図
である。FIG. 15 is a longitudinal sectional view schematically showing removal of the overhang member.

【図１６】従来の口元止水装置の台座への仮装着状態を
概略的に示す縦断面図である。FIG. 16 is a longitudinal sectional view schematically showing a state in which a conventional mouth water stopping device is temporarily mounted on a pedestal.

【図１７】従来の口元止水装置の台座への装着過程を概
略的に示す縦断面図である。FIG. 17 is a longitudinal sectional view schematically showing a process of mounting a conventional mouth water stopping device on a pedestal.

【図１８】従来の口元止水装置の台座への装着完了状態
を概略的に示す縦断面図である。FIG. 18 is a longitudinal sectional view schematically showing a state in which the conventional mouth water stopping device is completely mounted on a pedestal.

【図１９】削孔部材を引き抜いた際の水および土砂の噴
出状態を概略的に示す縦断面図である。FIG. 19 is a longitudinal sectional view schematically showing a state of jetting water and earth and sand when the drilling member is pulled out.

【符号の説明】[Explanation of symbols]

１Ａ〜１Ｃ…削孔部材、１ａ…単位削孔部材、２…先端
ビット、３…介在部材、３ａ…張出部、３ｂ…支持凸
部、４…張出部材、４ａ…張出部、４ｂ，４ｃ…支持凸
部、４ｄ…ボルト挿通孔、４ｅ…管状部、５…介在部
材、５ａ…張出部、５ｂ…支持凸部、１０…口元止水装
置、１１…内側部材、１２…外側部材、１３…内側シー
ル材、１４…外側シール材、１５…板状部材、１６…ボ
ルト、１７…ナット、１８…ボルト挿通孔、２０…口元
止水装置、２１…内側部材、２２…外側部材、２３…内
側シール材、２４…外側シール材、２５…板状部材、２
６…ボルト、２７…ナット、２８…ボルト挿通孔、２２
ｄ，２９…連通孔、ｓ１〜ｓ４…間隙。1A to 1C: drilling member, 1a: unit drilling member, 2 ... tip bit, 3 ... intervening member, 3a ... overhanging portion, 3b ... support convex portion, 4 ... overhanging member, 4a ... overhanging portion, 4b , 4c: support projection, 4d: bolt insertion hole, 4e: tubular portion, 5: interposed member, 5a: overhanging portion, 5b: support projection, 10: water stop device, 11: inner member, 12: outer Member 13, inner seal material 14, outer seal material 15, plate-like member, 16 bolt, 17 nut, 18 bolt insertion hole, 20 water shutoff device, 21 inner member, 22 outer member , 23 ... inner sealing material, 24 ... outer sealing material, 25 ... plate-like member, 2
6 bolts, 27 nuts, 28 bolt insertion holes, 22
d, 29: communication hole, s1 to s4: gap.

Claims (6)

【特許請求の範囲】[Claims] 【請求項１】削孔機により削孔部材に回転および推進力
を与えながら対象地盤を削孔する場合において、前記削
孔部材と地盤の削孔口元との間を止水体により封止して
止水を図るに際して、 前記削孔部材の長手方向途中にまたは削孔部材の長手方
向途中に介在させた介在部材に張出部を設け、 前記削孔機による削孔部材の推進力により、前記張出部
を介して前記止水体を地盤内に押し込むことを特徴とす
る削孔口元止水方法。When drilling a target ground while applying rotation and propulsion to a drilling member by a drilling machine, a gap between the drilling member and a drilling opening of the ground is sealed by a water blocking body. When water is stopped, a projecting portion is provided on an intervening member that is interposed in the longitudinal direction of the drilling member or in the longitudinal direction of the drilling member, and the propulsion force of the drilling member by the drilling machine causes A method for stopping water at a drilling hole, wherein the water stopping body is pushed into the ground through an overhang. 【請求項２】前記削孔部材の長手方向途中に張出部材を
着脱自在に設け、前記止水体の地盤内への押し込みに先
立って前記張出部材を前記削孔部材に固定して前記張出
部として用い、前記止水体の地盤内への押し込みが完了
した後に、前記張出部材を取り外す請求項１記載の削孔
口元止水方法。2. A projecting member is provided detachably in the longitudinal direction of the drilling member, and the projecting member is fixed to the drilling member before the water stopping body is pushed into the ground. The drilling hole base water stopping method according to claim 1, wherein the projecting member is removed after the water stopping body has been pushed into the ground and used as a projecting portion. 【請求項３】前記介在部材を前記削孔部材に着脱自在と
し、前記止水体の地盤内への押し込みに先立って前記介
在部材を前記削孔部材に連結し、前記止水体の地盤内へ
の押し込みが完了した後に、前記介在部材を取り外す請
求項１記載の削孔口元止水方法。3. The interposing member is detachably attached to the drilling member, and the intervening member is connected to the drilling member prior to pushing the water stopping body into the ground, and the water stopping body is inserted into the ground. 2. The method of claim 1, wherein the interposed member is removed after the pushing is completed. 【請求項４】前記削孔部材はケーシングからなる請求項
１〜３のいずれか１項記載の削孔口元止水方法。4. The method according to claim 1, wherein said drilling member comprises a casing. 【請求項５】削孔機により削孔部材に回転および推進力
を与えながら対象地盤を削孔する場合において、前記削
孔部材と地盤の削孔口元との間を封止して止水を図る削
孔口元止水装置であって、 前記削孔部材が貫通される管状部と、これと一体となっ
て半径方向に張り出すフランジ部とを有し、 前記装置の長手方向に離間する少なくとも２か所におい
て、装置と一体となり前記削孔部材の外周面に接するシ
ール材を備えることを特徴とする削孔口元止水装置。5. When drilling a target ground while applying rotation and propulsive force to a drilling member by a drilling machine, sealing between the drilling member and a drilling hole base of the ground to prevent water stoppage. A drilling hole base water stop device, comprising: a tubular portion through which the drilling member is penetrated; and a flange portion integrally extending with the tubular portion and extending in a radial direction, at least separated in a longitudinal direction of the device. A drill hole opening water stop device comprising a seal member integrated with the device at two locations and in contact with an outer peripheral surface of the drilling member. 【請求項６】削孔機により削孔部材に回転および推進力
を与えながら対象地盤を削孔する場合において、前記削
孔部材と地盤の削孔口元との間を封止して止水を図る削
孔口元止水装置であって、 前記削孔部材が貫通される管状部と、これと一体となっ
て半径方向に張り出すフランジ部とを有し、 前記装置の長手方向に離間する少なくとも２か所におい
て、装置と一体となり前記削孔部材の外周面に接するシ
ール材を備え、 さらに、前記管状部内と前記フランジ部外面とを連通す
る排水通路が設けられていることを特徴とする削孔口元
止水装置。6. When drilling a target ground while applying rotation and propulsive force to a drilling member by a drilling machine, sealing between the drilling member and a drilling hole base of the ground to prevent water stoppage. A drilling hole base water stop device, comprising: a tubular portion through which the drilling member is penetrated; and a flange portion integrally extending with the tubular portion and extending in a radial direction, at least separated in a longitudinal direction of the device. At two locations, a seal member is provided integrally with the device and in contact with the outer peripheral surface of the drilling member, and a drainage passage communicating between the inside of the tubular portion and the outer surface of the flange portion is provided. Water stop device at the mouth of the hole.