JP3586525B2

JP3586525B2 - Reducer for underground ventilation in shield tunnel construction etc.

Info

Publication number: JP3586525B2
Application number: JP29126596A
Authority: JP
Inventors: 西明彦中; 田勝秀和; 井竜司筒; 田敏雄下
Original assignee: 株式会社イズミ
Priority date: 1996-10-15
Filing date: 1996-10-15
Publication date: 2004-11-10
Anticipated expiration: 2016-10-15
Also published as: JPH10122207A

Description

【０００１】
【発明の属する技術分野】
本発明は主としてシールドトンネル工事において、坑内、特に掘削先端の切羽側に新鮮な空気を供給して、坑内の換気をするため、当該坑内に配備される風管の接続部分に使用して有用なレジューサに関するものである。
【０００２】
【従来の技術】
従来より、シールド工法などによるトンネル等のような坑道築造工事においては、図３に例示するように坑内Ｔに新鮮な空気又は外気を供給すると共に、坑内の空気を外部へ排出するため、その坑内Ｔに風管ＦＡと称される送気管が配置される。この風管ＦＡの後端には、通常、坑外に配置する送風機Ｂが接続され、この送風機Ｂによって外部の新鮮な空気又は外気が坑内、特に、切羽ＣＴの側に送られ、切羽ＣＴ側の熱気を含んだ空気と換気するようにしている。
【０００３】
しかし、シールド工法のトンネルでは、切羽ＣＴに対面する位置したシールドマシンＳＭが配置され、諸々の設備，機器類を搭載した後続台車ＴＲが前記シールドマシンＳＭの後に接続配備されることにより、これらが、切羽側に近いトンネル断面の大半を占有するため、前記風管ＦＡを切羽ＣＴの近くまで延設できないという問題があった。（図３参照）
【０００４】
上記問題点の改善方法として、図４，図５に示す送気方式が提案乃至は実施されているので、次にこの点について説明する。
【０００５】
図４の送気方式は、図３の従来送気方式に加え、後続台車ＴＲから切羽ＣＴの側にかけて、細目の第二風管ＦＡ′を配置すると共にこの第二風管ＦＡ′に専用の中継送風機Ｂ′を取付けた方式である。
【０００６】
ところが、図４の方式をとると、切羽ＣＴ側から坑道Ｔの後方へ向う熱気を帯びた風ｈＷ（図４に鎖線で示す）と、第一の風管ＦＡの先端から切羽側に向う冷風ｃＷとが、風管ＦＡの先端と第２風管ＦＡ′の送風機Ｂ′との近傍で衝突して滞留し、冷風ｃＷが第２風管ＦＡ′から切羽側に効率よく送給されにくい、つまり、換気効率が上らないという問題がある。
【０００７】
図４の方式の問題点に対処するため、図５に示すように、第一風管ＦＡと第二風管ＦＡ′の間を、蛇腹状の伸縮管Ｂｐを介してレジューサＲｅにより接続し、図４の例のような滞流や衝突による乱流が発生しないようにしたものが提案された。
しかし、この方式のものは、空気流路である風管の口径が途中で小さくなるため、風管抵抗が増大して送風機Ｂの能力が限定され、例えば送風機Ｂからの送風距離が大きくなると、途端に送風効率が低下するという別の問題がある。
【０００８】
【発明が解決しようとする課題】
本発明はこのような点に鑑み、径の異なる第一風管と第二風管とを接続しても従来のような問題点のない坑内換気用のレジューサを提供することを、その課題とするものである。
【０００９】
【課題を解決するための手段】
上記課題を解決することを目的としてなされた本発明レジューサの構成は、前後で開口径が異なる短か目の異径筒体の大径側の中心部に、当該筒体の小径側の内径よりも少し大きい開口径を有する短直管を配置して成り、前記筒体の小径側に第二風管を接続すると共に、前記短直管に伸縮管を介して第一風管を接続するようにしたことを特徴とするものである。ここで、第二風管とレジューサはシールドマシンの後続台車に支持させても、坑内の壁に支持させてもよい。第一風管をレジューサの短直管に直接接続する場合には、坑内の壁に支持させ、シールドマシンや台車の移動に合わせ、レジューサ後方の第一風管を継ぎ足すことにより、該レジューサ部分を適宜タイミングで前方へ移動させるか、又は、レジューサの異形筒体の小径側と第二風管の間に伸縮管を介在させて、シールドマシンや台車の移動に追従させる。
【００１０】
【発明の実施の形態】
次に本発明の実施の形態を図に拠り説明する。図１は本発明レジューサを用いたシールド工法トンネルにおける送気システムの形態例を示す側断面図、図２は図１における要部の拡大側断面図である。なお、図１において、図３〜図５と同一符号は同一部分を又は同一部材を指すものとする。
【００１１】
本発明レジューサＲｅは、図２に例示したように、前端２（出口側）と後端３（入口側）とで内径の異なる短か目の異形筒体１の内部中心に、前端２の内径ｃと少なくとも同等以上の内径ｂ、望ましくは、前端２の内径ｃと後端３の内径ａの中間程度の内径ｂを有する短直管４を、支持リブ５を介して配置することにより、形成されている。ここで、各径ａ，ｃ，ｂの関係はｂ²≒ａ²−ｃ²程度であることが望ましい。
【００１２】
本発明レジューサＲｅは、異径筒体１の小径側の先端２に第二風管ＦＡ′を接続する一方、大径側の後端３は開放しておき、この部に位置付けられた短直管４の後端に、図示しないが、第一風管ＦＡの先端を直接に接続するか、又は、図２に示すように伸縮管Ｂｐを介して第一風管ＦＡの先端側を接続して、使用をするものである。
【００１３】
ここで、上記伸縮管Ｂｐは、通常折畳み状態でカプセルＣｐに収容され、当該カプセルＣｐが台車ＴＲに支持されている。従って、坑内Ｔの壁に固定されて移動しない第一風管ＦＡの先端と、台車ＴＲの坑内前進により前方へ移動する本発明のレジューサＲｅは、前記伸縮管Ｂｐが伸長することにより、連結状態が保持される。上記伸縮管Ｂｐが伸び切った場合には、上記レジューサＲｅの短直管４と伸びた伸縮管Ｂｐの間に、新しい伸縮管Ｂｐを挿入するか、又は、上記の伸びた伸縮管Ｂｐと第一風管ＦＡの接合を解き、伸びた伸縮管Ｂｐを再び縮小させてカプセルＣｐ内に入れ、該伸縮管Ｂｐと第一風管ＦＡの間に接続用風管（図示せず）を挿入して接続すればよい。なお、第一風管ＦＡを短直管４に直結する場合には、第二風管ＦＡ′と前記筒体１の先端２の間に、伸縮管（図示せず）を介在させることとなる。
【００１４】
上記のように構成した換気システムでは、図２の本発明レジューサＲｅを通して第一風管ＦＡから第二風管ＦＡ′に送風すると、次のような現象が生じる。
即ち、図２に例示するように、第一風管ＦＡより送られて来た空気ｃＷは、レジューサＲｅの小径側の先端２の側に抜ける空気ｃＷと、このレジューサＲｅの口径が絞り込まれた部分1aに当り、当該レジューサＲｅの開放された後端３の側へ向け逆流する空気ｒＷとに分散されるが、レジューサＲｅの後端側へ向けて漏出する第一風管ＦＡからの空気ｒＷは、切羽ＣＴ側から逆流して来る熱風ｈＷと合流し、同じ方向の空気流として坑口側に滞流することなく流れ出る一方、先端２の側に抜けた冷風は、第二風管ＦＡ′の先端までストレスなく流れるため、送風機Ｂに余計な負坦をかけず、しかも切羽ＣＴ側へは新鮮な空気が常時効率よく供給できることとなるのである。
【００１５】
【発明の効果】
上述のように、本発明では坑内換気用のレジューサを出入口で径の異なる異径筒体と短直管体とを同軸上で組合せた複合構造体としたから、従来のレジューサのように、単に切羽側に配置した小径の風管と坑口側に配置した大径の風管を接続するため、筒体の前，後で口径を異なるだけに形成したものと異なり、送風機に余計な負坦をかけず、しかも、切羽側から逆流して来る熱風を巧みに坑口側へ導出する空気流を作ることができるという、従来の坑内換気用のレジューサでは得られない換気効果をもたらす。
【図面の簡単な説明】
【図１】本発明レジューサを用いたシールド工法トンネルにおける送気システムの形態例を示す側断面図。
【図２】図１における要部の拡大側断面図。
【図３】従来の坑内換気状態の一例の側断面図。
【図４】従来の坑内換気状態の他の例の側断面図。
【図５】従来の坑内換気状態の別の例の側断面図。
【符号の説明】
１異径筒体
２前端
３後端
４短直管
５支持リブ
Ｒｅレジューサ
ａ，ｂ，ｃ口径
ＦＡ第一風管
ＦＡ′ 第二風管
Ｂｐ伸縮管
Ｃｐカプセル
ＣＴ切羽
Ｂ，Ｂ′ 送風機[0001]
TECHNICAL FIELD OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention is mainly used in shield tunnel construction, in which fresh air is supplied to the inside of a pit, particularly to the face side of the excavation tip to ventilate the inside of the pit. It is about reducers.
[0002]
[Prior art]
Conventionally, in a tunnel construction work such as a tunnel by a shield method or the like, as shown in FIG. 3, fresh air or outside air is supplied to a mine T, and air in the mine is discharged to the outside. An air supply pipe called a wind pipe FA is arranged at T. The rear end of the wind pipe FA is connected to a blower B which is usually disposed outside the mine. The blower B sends external fresh air or outside air to the inside of the mine, particularly to the face CT, and the face CT side. I try to ventilate with hot air.
[0003]
However, in the tunnel of the shield method, the shield machine SM facing the face CT is arranged, and the succeeding bogie TR mounted with various facilities and devices is connected and arranged after the shield machine SM, so that these are arranged. However, since the tunnel cross section occupies most of the tunnel section close to the face, there is a problem that the wind pipe FA cannot be extended near the face CT. (See Fig. 3)
[0004]
As a method for solving the above problem, the air supply method shown in FIGS. 4 and 5 has been proposed or implemented, and this point will be described below.
[0005]
The air supply system shown in FIG. 4 is different from the conventional air supply system shown in FIG. 3 in that a fine second air duct FA 'is arranged from the trailing bogie TR to the face CT side and a dedicated second air duct FA' is provided. This is a system with a relay blower B 'attached.
[0006]
However, when the method shown in FIG. 4 is adopted, hot wind hW (shown by a dashed line in FIG. 4) from the face CT to the rear of the tunnel T, and cold wind from the tip of the first wind tube FA toward the face. cW collides and stays in the vicinity of the tip of the wind pipe FA and the blower B 'of the second wind pipe FA', and it is difficult for the cool air cW to be efficiently fed from the second wind pipe FA 'to the face side. That is, there is a problem that ventilation efficiency does not increase.
[0007]
In order to cope with the problem of the method of FIG. 4, as shown in FIG. 5, the first wind pipe FA and the second wind pipe FA ′ are connected by a reducer Re via a bellows-shaped telescopic pipe Bp, As shown in FIG. 4, a turbulent flow due to a stagnant flow or collision has been proposed.
However, in this type, since the diameter of the air tube, which is the air flow path, becomes smaller in the middle, the air tube resistance increases and the capacity of the blower B is limited. For example, when the blowing distance from the blower B increases, There is another problem that the blowing efficiency is reduced immediately.
[0008]
[Problems to be solved by the invention]
In view of the above, the present invention has been made to provide a reducer for downhole ventilation that does not have a problem as in the related art even when the first wind pipe and the second wind pipe having different diameters are connected. Is what you do.
[0009]
[Means for Solving the Problems]
The configuration of the reducer of the present invention made for the purpose of solving the above-mentioned problem is such that the central portion on the large-diameter side of the short or different-diameter cylindrical body having different opening diameters before and after the inner diameter on the small-diameter side of the cylindrical body. A short straight pipe having a slightly larger opening diameter is arranged, and a second wind pipe is connected to the small diameter side of the cylindrical body, and a first wind pipe is connected to the short straight pipe via a telescopic pipe. It is characterized by the following. Here, the second wind tube and the reducer may be supported by a trailing bogie of the shield machine or may be supported by a wall in a pit. When the first wind tube is directly connected to the short straight pipe of the reducer, the reducer portion is supported by the wall of the downhole, and the first wind tube at the rear of the reducer is added in accordance with the movement of the shield machine or bogie. Is moved forward at an appropriate timing, or a telescopic tube is interposed between the small-diameter side of the deformed cylindrical body of the reducer and the second air tube to follow the movement of the shield machine or the bogie.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing an embodiment of an air supply system in a shield tunnel using the reducer of the present invention, and FIG. 2 is an enlarged side sectional view of a main part in FIG. In FIG. 1, the same reference numerals as those in FIGS. 3 to 5 indicate the same parts or the same members.
[0011]
As illustrated in FIG. 2, the reducer Re of the present invention includes an inner diameter of the front end 2 at the center of the inside of the short-shaped deformed cylindrical body 1 having different inner diameters at the front end 2 (outlet side) and the rear end 3 (inlet side). a short straight pipe 4 having an inner diameter b at least equal to or more than c, preferably an intermediate diameter b between the inner diameter c of the front end 2 and the inner diameter a of the rear end 3 is formed by arranging through the support rib 5. Have been. Here, it is desirable that the relationship among the diameters a, c, and b is approximately b ² ≒ a ² −c ² .
[0012]
In the reducer Re of the present invention, the second wind pipe FA 'is connected to the distal end 2 on the small diameter side of the different diameter cylindrical body 1, while the rear end 3 on the large diameter side is left open, Although not shown, the front end of the first air duct FA is directly connected to the rear end of the pipe 4, or the front end side of the first air duct FA is connected via a telescopic pipe Bp as shown in FIG. And use it.
[0013]
Here, the telescopic tube Bp is normally accommodated in the capsule Cp in a folded state, and the capsule Cp is supported by the cart TR. Accordingly, the distal end of the first wind pipe FA fixed to the wall of the pit T and not moving and the reducer Re of the present invention which moves forward due to the advance of the bogie TR under the pit are connected to each other by the expansion and contraction of the telescopic pipe Bp. Is held. When the telescopic tube Bp has been completely extended, a new telescopic tube Bp is inserted between the short straight tube 4 of the reducer Re and the telescopic tube Bp that has expanded, or the telescopic tube Bp and the second telescopic tube that have been stretched are connected to each other. The joint of the one air tube FA is released, the expanded telescopic tube Bp is reduced again, put into the capsule Cp, and a connecting air tube (not shown) is inserted between the telescopic tube Bp and the first air tube FA. Connection. When the first wind pipe FA is directly connected to the short straight pipe 4, a telescopic pipe (not shown) is interposed between the second wind pipe FA 'and the distal end 2 of the tubular body 1. .
[0014]
In the ventilation system configured as described above, when air is sent from the first air duct FA to the second air duct FA 'through the reducer Re of the present invention in FIG. 2, the following phenomenon occurs.
That is, as illustrated in FIG. 2, the air cW sent from the first air duct FA has the air cW that escapes toward the tip 2 on the smaller diameter side of the reducer Re, and the diameter of the reducer Re is narrowed down. The air rW colliding with the portion 1a and flowing back toward the open rear end 3 of the reducer Re is dispersed into the air rW from the first air duct FA leaking toward the rear end of the reducer Re. Merges with the hot air hW flowing backward from the face CT side and flows out without stagnating at the wellhead side as an airflow in the same direction, while the cool air that has escaped to the tip 2 side is discharged from the second wind pipe FA ′. Since the air flows to the tip without any stress, no extra load is applied to the blower B, and fresh air can always be efficiently supplied to the face CT.
[0015]
【The invention's effect】
As described above, in the present invention, the reducer for underground ventilation is a composite structure in which different diameter cylinders and short straight pipes having different diameters at the entrance and exit are coaxially combined. In order to connect the small-diameter wind pipe located on the face side and the large-diameter wind pipe located on the wellhead side, unlike the one formed only with a different diameter before and after the cylindrical body, extra negative carrier is required for the blower. In addition, a ventilation effect that cannot be obtained with a conventional underground ventilation reducer can be obtained, in which an air flow that can efficiently guide hot air flowing backward from the face side to the wellhead side can be created.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing an example of an air supply system in a shield tunnel using a reducer according to the present invention.
FIG. 2 is an enlarged side sectional view of a main part in FIG.
FIG. 3 is a side sectional view of an example of a conventional underground ventilation state.
FIG. 4 is a side sectional view of another example of the conventional underground ventilation state.
FIG. 5 is a side sectional view of another example of a conventional underground ventilation state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Different diameter cylinder 2 Front end 3 Rear end 4 Short straight pipe 5 Support rib Re Reducer a, b, c Diameter FA First wind pipe FA 'Second wind pipe Bp Telescopic pipe Cp Capsule CT Face B, B' Blower

Claims

A short straight pipe having an opening diameter slightly larger than the inner diameter of the small-diameter side of the cylindrical body is arranged at the center of the large-diameter side of the short-diameter cylindrical body having a different opening diameter before and after, A reducer for underground ventilation in shield tunnel construction or the like, wherein a second wind pipe is connected to the small diameter side of the body, and a first wind pipe is connected to the short straight pipe via a telescopic pipe.

2. The underground ventilation reducer according to claim 1, wherein a front end of the first wind pipe is directly connected to a rear end of the short straight pipe.