JPH08303188A - Shield machine - Google Patents

Abstract

PURPOSE: To prevent the generation of retention and closing in a sludge withdrawal pipe due to stone contained in soil and sand in a facing, and to discharge soil and sand in the facing smoothly to the rear. CONSTITUTION: A shield machine has a bulkhead 2 parting a facing 32 and an underground section in a section immediately after a cutter head 7 excavating a bedrock 36 in a front section. A sludge discharge opening 4 for discharging soil and sand in the facing is formed and a stop gate 3 opening and closing the sludge discharge opening 4 is fitted to the bulkhead 2. A sludge withdrawal pipe 13 passing soil and sand in the facing through the rear section of the machine is connected to the sludge discharge opening 4. The sectional shape of the sludge withdrawal pipe 13 is formed in an elliptical cross section expanded in the horizontal direction, and the major axis of the sludge withdrawal pipe 13 is formed in 1.15-1.30 to a minor axis. A trommel 14 separating stone contained in soil and sand in the facing into mud and sand while being rotated is installed at the terminal of the sludge withdrawal pipe 13.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、セミシールド工法によ
る導水路や下水道等のトンネルの掘削に用いられるシー
ルド掘進機であって、石が含まれる切羽内土砂を、滞留
や詰まりを起こさせずに後方へ排出する、シールド掘進
機に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield machine used for excavating tunnels such as headraces and sewers by the semi-shield construction method, which does not cause retention or clogging of earth and sand in the face containing stones. It relates to a shield machine that discharges backwards.

【０００２】[0002]

【従来の技術】シールド掘進機を先導体とし、その直後
へ地山を支える管体を後方の発進立坑内のジャッキで押
し込んで推進させながら埋設していくセミシールド工法
による、導水路や下水道等の内径０.８〜１.２ｍ程度の
トンネル掘削において用いるシールド掘進機では、切羽
内圧力を保持して掘削地山を支えるため、バルクヘッド
前方の切羽内に泥土を圧入している。この切羽に圧入し
た泥土は、掘削した土砂と混合して流動性をもつ切羽内
土砂を形成する。切羽内土砂は、バルクヘッドの排泥口
から、この排泥口と掘進機後方のトロンメルとを接続す
る排泥管内に導入される。この後切羽内土砂は排泥管を
通り、トロンメルで石と泥土・砂に分離され、それぞれ
別に地上へ回収される。これら切羽内土砂が通る排泥管
は、従来は円断面の一般的な形状の管が用いられてき
た。こうした管内では、上層に比重が軽く粒子の細かい
土などが、下層に比重が重く形の大きい石などが集まり
やすい傾向にある。切羽内土砂に含まれる石は、多くが
長径と短径の比が１：０.７程度の楕円体形状の玉石で
あるので、管内で石の上側に別の石が重なって流れるこ
ともよくある。このため、上下の石がかかわり合って管
内の流れを滞らせ、排出速度が遅くなるばかりでなく、
管内壁に石がはまって外れなくなると管の閉塞が起き
て、掘進機全体の運転の支障となっていた。2. Description of the Related Art A semi-shield construction method in which a shield machine is used as a front conductor, and immediately after that, a tube that supports the ground is pushed by a jack in the starting shaft behind and buried while promoting In a shield machine used in tunnel excavation with an inner diameter of about 0.8 to 1.2 m, mud is pressed into the face in front of the bulkhead in order to maintain the pressure inside the face and support the excavated ground. The mud pressed into this face mixes with the excavated earth and sand to form a fluid face inside the face. Sediment in the cutting face is introduced from the mud discharge port of the bulkhead into the mud discharge pipe that connects the mud discharge port and the trommel behind the machine. After this, the earth and sand in the cutting face passes through the mud pipe, is separated by trommel into stone and mud and sand, and is collected separately on the ground. As the mud discharge pipe through which the earth and sand inside the cutting face pass, a pipe having a generally circular cross section has been conventionally used. In such a pipe, soil with small specific gravity and fine particles tends to gather in the upper layer, and stones with large specific gravity and large shapes tend to gather in the lower layer. Most of the stones contained in the earth and sand in the face are ellipsoidal-shaped boulders with a ratio of major axis to minor axis of about 1: 0.7, so it is easy for another stone to flow over a stone in the pipe. is there. For this reason, not only the upper and lower stones are involved but the flow in the pipe is stagnated, and not only the discharge speed slows down, but also
When stones stuck to the inner wall of the pipe and could not be removed, the pipe was blocked, which hindered the operation of the entire excavator.

【０００３】[0003]

【発明が解決しようとする課題】本発明が解決しようと
する課題は、上記した問題点を解決し、石による滞留・
閉塞が発生しにくく、切羽内土砂をスムーズに後方へ排
出できるシールド掘進機を提供することにある。The problem to be solved by the present invention is to solve the above-mentioned problems and
(EN) It is intended to provide a shield machine which is less likely to be clogged and which can smoothly discharge the earth and sand in a face to the rear.

【０００４】[0004]

【課題を解決するための手段】かかる課題を解決した本
発明の構成は、トンネル前方で地山を掘削するカッター
ヘッドの後側に、切羽と坑内とを隔てるバルクヘッドを
設け、同バルクヘッドに切羽内土砂排出用の排泥口を設
け、後方に設けられた泥土・砂と石を分離するトロンメ
ルとこの排泥口を排泥管で接続する、トンネル掘削用の
シールド掘進機において、排泥管の内部断面形状が水平
方向に長くした楕円断面で、その長径が短径の１.１５
〜１.３０倍となっていることを特徴とするシールド掘
進機にある。SUMMARY OF THE INVENTION The structure of the present invention, which has solved the above-mentioned problems, is provided with a bulkhead separating a face and a mine behind a cutterhead for excavating the ground in front of a tunnel. A shield excavator for tunnel excavation that has a mud discharge port for discharging sediment in the face, and a trommel that is provided in the rear to separate mud, sand, and stones and this mud discharge port is connected by a mud pipe. The internal cross-sectional shape of the pipe is an elliptical cross-section that is long in the horizontal direction, and the major axis is 1.15 with the minor axis.
It is in a shield machine, which is characterized by being up to 1.30 times.

【０００５】[0005]

【作用】本発明のシールド掘進機では、切羽内土砂を排
出するため排泥口を開放すると、バルクヘッドで隔てら
れた切羽と掘進機内部を含む坑内との圧力差によって排
泥口から切羽内土砂が排泥管内に流れ込む。排泥口は切
羽内圧力保持のため、断続的にしか開放されないが、排
出時の高い排出圧力により、流れ込んだ切羽内土砂は排
泥管内を後方に向かって進んで行く。排泥管内の断面形
状は、水平方向に拡がった楕円断面で、その長径が短径
の１.１５〜１.３０倍になっており、同じ断面積の円管
よりも管内の上部および下部の面の曲率が小さく、楕円
体形状の玉石の形に合う断面形状であるため、管内で玉
石が上下に二個重なって円管ならば詰まるような場合で
も、下の石が円管に比べて、より管内下方まで下がるこ
とができ、上側の石が下側の石を乗り超えるための残り
の空間が大きくなる。そしてこの残りの空間も円管に比
べて水平方向に広く、より玉石に適したものであるか
ら、重なった石を詰まらせずに流すことができる（図
７、図８参照）。土砂全体に対しても、管内が円管より
も上下に小さく、水平方向に広いので、土や砂・石など
の上下への偏在が起こりにくく、管内をこれら大きさの
異なるものがほどよく分散した状態で流すことができ
る。このようにして管内を流れて進んだ土砂・石は掘進
機後方のトロンメルに入り、土砂と石が分離されてそれ
ぞれ外部に回収される。排泥管の長径が短径に対する
１.１５〜１.３０倍という範囲を外れると、長径が１.
１５倍より小さい場合には石をスムーズに通す効果がな
く円管同様玉石が上下に重なって詰まる割合が多くな
る。逆に長径が１.３０倍より大きい場合には、管内の
上下の間隔が詰まり過ぎて、流せる最大の石の寸法が同
じ断面積の円管に比べ小さくなってしまい、楕円体形状
以外の石が通りにくくなる。In the shield machine of the present invention, when the mud opening is opened to discharge the earth and sand in the face, the pressure difference between the face separated by the bulkhead and the inside of the machine including the inside of the machine causes the inside of the face to be cut. Sediment flows into the mud pipe. The mud discharge port is opened only intermittently to maintain the pressure inside the cutting face, but due to the high discharge pressure at the time of discharge, the sediment inside the cutting face moves backward in the mud pipe. The cross-sectional shape of the sludge pipe is an elliptical cross-section that expands in the horizontal direction, and the major axis is 1.15 to 1.30 times the minor axis. Since the curvature of the surface is small and the cross-sectional shape matches the shape of an ellipsoidal cobblestone, even if two cobblestones are piled up and down in the pipe and a circular pipe is clogged, the lower stone is compared to the circular pipe. , It is possible to go down to the lower part of the pipe, and the remaining space for the upper stone to get over the lower stone becomes large. The remaining space is wider in the horizontal direction than the circular pipe and is more suitable for boulders, so that overlapping stones can be flowed without clogging (see FIGS. 7 and 8). Even for the whole earth and sand, the inside of the pipe is smaller than the circular pipe vertically and is wide in the horizontal direction, so uneven distribution of soil, sand, stones etc. is unlikely to occur, and those of different sizes are moderately dispersed in the pipe It can be drained as it is. The earth and sand and stones that have flowed through the pipe in this way enter the trommel behind the excavator, where the earth and sand and stones are separated and collected outside. If the major axis of the sludge pipe deviates from the range of 1.15 to 1.30 times the minor axis, the major axis becomes 1.
If it is less than 15 times, there is no effect of smooth passage of stones, and as with circular pipes, the ratio of cobblestones that are piled up and down increases. On the other hand, if the major axis is larger than 1.30 times, the upper and lower spaces in the pipe are too close, and the size of the largest stone that can be flowed will be smaller than that of a circular pipe with the same cross-sectional area. Becomes difficult to pass.

【０００６】[0006]

【実施例】本発明の実施例を図面に基づいて説明する。
本実施例は、排泥管楕円断面の長径を短径の１.２５倍
としたシールド掘進機の例である。図１は実施例を示す
正面図、図２は実施例の前半部分の垂直断面図、図３は
実施例の後半部分の垂直断面図、図４は実施例の前半部
分の水平断面図、図５は実施例の後半部分の水平断面
図、図６は図２のＡ−Ａ断面図、図７は実施例の排泥管
内流動状態を示す説明図、図８は従来の排泥管内流動状
態を示す説明図、図９は実施例を用いたトンネル掘削作
業を示す説明図である。本実施例のシールド掘進機１
は、最前方で回転して地山３６の掘削を行なうカッター
ヘッド７の直後に切羽３２と坑内作業空間を隔てるバル
クヘッド２がある。カッターヘッド７を駆動する機構
は、シールド８内の減速機付電動機９で発生する駆動力
を、バルクヘッド２中央を貫通する回転主軸１０に歯車
１１を介して伝え、回転主軸１０と直結したカッターヘ
ッド７を回転させる仕組みとしている。一方、バルクヘ
ッド２には切羽内土砂排出用の排泥口４や、切羽内圧力
を検知する圧力センサ５用の圧力導入孔６、および切羽
圧入用泥土供給口１２を設けると共に、排泥口４を開閉
するストップゲート３を取付けている。排泥口４には、
ここから導入される切羽内土砂をシールド掘進機１後部
へ通す排泥管１３が接続している。この排泥管１３の断
面形状は水平方向に拡がった楕円断面であり、その長径
Ｌを短径Ｒに対して１.２５倍としている（図７参
照）。排泥管１３の終端には駆動装置１５により回転し
ながら切羽内土砂に含まれる石３４を泥土や砂と分離す
るトロンメル１４を設置している。分離された泥土や砂
を収容する貯泥槽１６は地上に設けたタンク２７と排泥
パイプ２２で接続され、同じく地上の真空吸引装置２６
からの吸引力がここまで伝わるようにしている。一方ト
ロンメル１４で分離された石３４の排出手段として、立
坑３５部まで石３４を運搬するトロッコ２４が設置され
る。逆に切羽３２へ泥土を圧入するために、泥土を供給
する送泥装置２８を地上に設け、送泥パイプ２３でバル
クヘッド２の泥土供給口１２と接続している。こうした
各装置が接続されたシールド掘進機１は、立坑３５内に
設置される元押しジャッキ２５からの押圧力を地山３６
を支えるヒューム管３１を介して最後端の受圧部１８で
受け、これを支えとしながら、受圧部１８の直前にある
中押しジャッキ１７で推進する仕組みである。本実施例
のシールド掘進機１を用いたトンネルの掘削方法では、
地上の送泥装置２８から送泥パイプ２３を通して圧送さ
れる泥土をバルクヘッド２の泥土供給口１２から切羽３
２内に圧入し、切羽内圧力を高くして地山３６の崩壊を
防ぎながら、カッターヘッド７を回転させて掘削を行な
っていく。掘削と同時にシールド掘進機１は中押しジャ
ッキ１７により推進し、所定量推進すると、その分元押
しジャッキ２５によりヒューム管３１が押し込まれて、
トンネル部分の地山３６が支えられると共にシールド掘
進機１全体が前進した形になる。カッターヘッド７で掘
削された土砂３３や石３４は、切羽３２に圧入した泥土
と混合され、流動性を持った切羽内土砂として切羽内圧
力を維持し掘削地山の崩壊を防ぐ役割を果たす。切羽内
土砂の量が増大して切羽内圧力が適正値を超えた場合に
は、バルクヘッド２のストップゲート３により、排泥口
４を開いて土砂を排出する。切羽内圧力が下がると、ス
トップゲート３により再び排泥口４を閉鎖して、切羽内
圧力が下がり過ぎないようにしている。排泥口４から導
入された切羽内土砂は排泥管１３に入り、管内を土と砂
および石が混合した状態で進む。排泥管１３は水平方向
に拡がった楕円断面であり、その長径が短径の１.２５
倍のため、楕円体形状の玉石を含む土砂が均等に分散
し、石も詰まらず、整然と流れる。排泥管の内径の比が
上記の範囲を外れると、円管同様玉石が上下に重なって
詰まり易かったり、逆に管内上下間隔が縮まり過ぎて、
流せる最大の玉石の寸法が同じ断面積の円管に比べ小さ
くなったりするため、本実施例の長径と短径の比のもの
が実用性が高い。土砂および石３４は排泥管１３を通っ
てから、トロンメル１４に達し、石３４と泥土・砂に分
離される。泥土および砂は貯泥槽１６に入り、真空吸引
装置２６で吸引されて排泥パイプ２２を通り、タンク２
７へ回収される。タンク２７に回収された泥土の一部
は、送泥装置２８に送られて再び切羽３２へ戻される。
一方、トロンメル１４で分離された石３４はまとめてト
ロッコ２４により立坑３５部まで運ばれ、外部に搬出さ
れる。シールド掘進機１内部は、トロンメル１４部まで
後方から作業者が入って作業することができ、トロンメ
ル１４で土砂が詰まったりした場合には作業者が直接除
去等を行う。An embodiment of the present invention will be described with reference to the drawings.
The present embodiment is an example of a shield machine in which the major axis of the elliptical section of the sludge discharge pipe is 1.25 times the minor axis. 1 is a front view showing an embodiment, FIG. 2 is a vertical sectional view of a first half portion of the embodiment, FIG. 3 is a vertical sectional view of a second half portion of the embodiment, and FIG. 4 is a horizontal sectional view of a first half portion of the embodiment. 5 is a horizontal sectional view of the latter half of the embodiment, FIG. 6 is a sectional view taken along the line AA of FIG. 2, FIG. 7 is an explanatory view showing the flow state in the sludge pipe of the embodiment, and FIG. 8 is the conventional flow state in the sludge pipe. FIG. 9 is an explanatory view showing a tunnel excavation work using the embodiment. Shield machine 1 of this embodiment
The bulkhead 2 that separates the face 32 and the underground working space immediately after the cutter head 7 that rotates at the forefront to excavate the natural ground 36. The mechanism for driving the cutter head 7 transmits the driving force generated by the electric motor 9 with a speed reducer in the shield 8 to the rotary main shaft 10 penetrating the center of the bulkhead 2 via the gear 11 to directly connect the rotary main shaft 10. The mechanism is such that the head 7 is rotated. On the other hand, the bulkhead 2 is provided with a mud discharge port 4 for discharging sediment in the face, a pressure introduction hole 6 for a pressure sensor 5 for detecting the pressure inside the face, and a mud supply port 12 for press-fitting the face. A stop gate 3 for opening and closing 4 is attached. In the mud discharge port 4,
A mud pipe 13 for connecting the earth and sand in the face introduced from here to the rear of the shield machine 1 is connected. The cross-sectional shape of the sludge pipe 13 is an elliptical cross-section that is expanded in the horizontal direction, and the major axis L is 1.25 times the minor axis R (see FIG. 7). At the end of the mud discharge pipe 13, a trommel 14 is installed which is rotated by a drive unit 15 to separate the stones 34 contained in the earth and sand from the face from the mud and sand. The mud storage tank 16 that stores the separated mud and sand is connected to a tank 27 provided on the ground by a mud discharge pipe 22, and also a vacuum suction device 26 on the ground.
The suction power from is transmitted to here. On the other hand, as a means for discharging the stones 34 separated by the trommel 14, a dolly 24 that transports the stones 34 to the shaft 35 is installed. On the contrary, in order to press the mud into the face 32, a mud feeding device 28 for feeding the mud is provided on the ground, and the mud feeding pipe 23 is connected to the mud feeding port 12 of the bulkhead 2. The shield machine 1 to which each of these devices is connected receives the pressing force from the source push jack 25 installed in the vertical shaft 35 as a natural ground 36.
The pressure receiving portion 18 at the rear end receives the pressure through the fume pipe 31 that supports the pressure hose, and the middle pressing jack 17 immediately in front of the pressure receiving portion 18 supports the pressure receiving portion 18. In the tunnel excavation method using the shield machine 1 of the present embodiment,
The mud fed under pressure from the mud sending device 28 on the ground through the mud sending pipe 23 is fed from the mud feeding port 12 of the bulkhead 2 to the face 3
2 is pressed into the inside of the face to increase the pressure inside the face to prevent the ground 36 from collapsing, and the cutter head 7 is rotated for excavation. Simultaneously with the excavation, the shield machine 1 is propelled by the middle pushing jack 17, and when the pushing amount is propelled by a predetermined amount, the fume pipe 31 is pushed by the former pushing jack 25,
The ground 36 of the tunnel portion is supported and the shield machine 1 as a whole is advanced. The earth and sand 33 and stones 34 excavated by the cutter head 7 are mixed with the mud soil press-fitted into the cutting face 32, and serve as fluid inside the cutting face to maintain the pressure inside the face and prevent the excavated ground from collapsing. When the amount of earth and sand in the face increases and the pressure in the face exceeds an appropriate value, the mud discharge port 4 is opened by the stop gate 3 of the bulkhead 2 to discharge the earth and sand. When the pressure inside the face decreases, the drainage port 4 is closed again by the stop gate 3 so that the pressure inside the face does not drop too much. The earth and sand in the cutting face introduced from the mud discharge port 4 enters the mud discharge pipe 13 and proceeds in the pipe in a state where soil, sand and stone are mixed. The sludge pipe 13 has an elliptical cross-section that extends horizontally, and its major axis is 1.25 with its minor axis being the minor axis.
Due to the double, the sand and sand containing the ellipsoidal cobblestones are evenly distributed, and the stones do not get clogged and flow neatly. When the ratio of the inner diameter of the sludge pipe is out of the above range, the boulders are piled up and down like the circular pipe and are easily clogged, or conversely, the vertical distance in the pipe is too short,
Since the size of the largest boulder that can be flowed is smaller than that of a circular pipe having the same cross-sectional area, the one having the ratio of the major axis to the minor axis of this embodiment is highly practical. The earth and sand and the stone 34 reach the trommel 14 after passing through the mud pipe 13, and are separated into the stone 34 and the mud / sand. The mud and sand enter the mud storage tank 16, are sucked by the vacuum suction device 26, pass through the mud discharge pipe 22, and enter the tank 2
Recovered to 7. A part of the mud collected in the tank 27 is sent to the mud sending device 28 and returned to the cutting face 32 again.
On the other hand, the stones 34 separated by the trommel 14 are collectively carried by the truck 24 to the shaft 35, and are carried out to the outside. Inside the shield machine 1, a worker can work from the rear up to the trommel 14 part. When the trommel 14 is clogged with soil, the worker directly removes it.

【０００７】[0007]

【発明の効果】本発明は、排泥管断面形状を水平に長
く、長径が短径の１.１５〜１.３０倍の楕円とした構成
を採用することにより、排泥管内を大きな石を含む土砂
がスムーズに流れて滞留・閉塞が起こりにくく、土砂・
石の排出が迅速に行える上、排泥管の詰まりを除く作業
の頻度が著しく減少するため、全体の掘進作業が効率良
く進められる。EFFECTS OF THE INVENTION According to the present invention, by adopting a construction in which the cross section of the sludge discharge pipe is horizontally long and has an ellipse whose major axis is 1.15 to 1.30 times the minor axis, a large stone is discharged inside the sludge pipe. Sediment including sand flows smoothly and retention and blockage are hard to occur,
The stones can be discharged quickly, and the frequency of work to clear the clogging of the mud pipe is significantly reduced, so that the overall excavation work can proceed efficiently.

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

【図１】実施例を示す正面図である。FIG. 1 is a front view showing an embodiment.

【図２】実施例の前半部分の垂直断面図である。FIG. 2 is a vertical sectional view of a first half portion of the embodiment.

【図３】実施例の後半部分の垂直断面図である。FIG. 3 is a vertical sectional view of the latter half of the embodiment.

【図４】実施例の前半部分の水平断面図である。FIG. 4 is a horizontal sectional view of a first half portion of the embodiment.

【図５】実施例の後半部分の水平断面図である。FIG. 5 is a horizontal sectional view of the latter half of the embodiment.

【図６】図２のＡ−Ａ断面図である。6 is a cross-sectional view taken along the line AA of FIG.

【図７】実施例の排泥管内流動状態を示す説明図であ
る。FIG. 7 is an explanatory diagram showing a fluidized state in the sludge discharge pipe of the embodiment.

【図８】従来の排泥管内流動状態を示す説明図である。FIG. 8 is an explanatory view showing a flow state in a conventional sludge discharge pipe.

【図９】実施例を用いたトンネル掘削作業を示す説明図
である。FIG. 9 is an explanatory diagram showing a tunnel excavation work using an example.

【符号の説明】[Explanation of symbols]

１ シールド掘進機 ２ バルクヘッド ３ ストップゲート ４ 排泥口 ５ 圧力センサ ６ 圧力導入孔 ７ カッターヘッド ８ シールド ９ 減速機付電動機 １０ 回転主軸 １１ 歯車 １２ 泥土供給口 １３ 排泥管 １４ トロンメル １５ 駆動装置 １６ 貯泥槽 １７ 中押しジャッキ １８ 受圧部 １９ パッキン ２０ ビクトリックジョイント ２１ 方向修正ジャッキ ２２ 排泥パイプ ２３ 送泥パイプ ２４ トロッコ ２５ 元押しジャッキ ２６ 真空吸引装置 ２７ タンク ２８ 送泥装置 ２９ 坑内送風用コンプレッサ ３０ エアパイプ ３１ ヒューム管 ３２ 切羽 ３３ 土砂 ３４ 石 ３５ 立坑 ３６ 地山 1 shield machine 2 bulkhead 3 stop gate 4 mud discharge port 5 pressure sensor 6 pressure introduction hole 7 cutter head 8 shield 9 electric motor with speed reducer 10 rotating main shaft 11 gear 12 mud supply port 13 drainage pipe 14 trommel 15 drive device 16 Mud tank 17 Medium push jack 18 Pressure receiving part 19 Packing 20 Vitric joint 21 Direction correction jack 22 Draining pipe 23 Mud sending pipe 24 Truck 25 Original push jack 26 Vacuum suction device 27 Tank 28 Mud sending device 29 Mine air blowing compressor 30 Air pipe 31 Hume pipe 32 Face 33 Soil 34 Stone 35 Vertical shaft 36 Rock

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 トンネル前方で地山を掘削するカッター
ヘッドの後側に、切羽と坑内とを隔てるバルクヘッドを
設け、同バルクヘッドに切羽内土砂排出用の排泥口を設
け、後方に設けられた泥土・砂と石を分離するトロンメ
ルとこの排泥口を排泥管で接続する、トンネル掘削用の
シールド掘進機において、排泥管内部の断面形状が水平
方向に長くした楕円断面で、その長径が短径の１.１５
〜１.３０倍となっていることを特徴とするシールド掘
進機。1. A bulkhead for separating a face and a mine is provided on the rear side of a cutter head for excavating the ground in front of a tunnel, and the bulkhead is provided with a sludge discharge port for discharging sediment in the face and provided on the rear side. In a shield excavator for tunnel excavation, in which a trommel that separates the mud, sand and stones that has been separated and this drainage port are connected by a drainage pipe, the cross-sectional shape of the inside of the drainage pipe is an elliptical cross section that is elongated in the horizontal direction. 1.15 whose major axis is the minor axis
~ 1.30 times the shield machine.