JP2003232195A - Tail seal structure of shield - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tail seal structure of a shield, which prevents a reversal of a tail brush and a degradation in cut-off properties. <P>SOLUTION: A main body is composed of a wire brush 21; the wire brush 21 is held in a state of being sandwiched between a plurality of inside protective plates 22 and a plurality of outside protective plates 25; at least two intermediate protective plates 23 and a wire net 24 are interposed within the wire brush 21, so that a tail seal 2 can be constituted. The wire brush 21 is formed so as to be long enough to have a clamping margin. The tail seals 2 are attached to a tail plate 15 in a state of being separated from each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield tail seal structure.

[0002]

2. Description of the Related Art Generally, the shield construction method assembles segments into a ring shape on the inner surface of the tail portion of a shield machine.
The reaction force is taken from this segment to excavate the shield machine. Since the outer diameter of the segment assembled in the shield machine is smaller than the inner diameter of the skin plate of the shield machine, there is tail clearance, and the tail plate is used to prevent groundwater, backfill material, etc. from entering the shield machine. A tail seal is installed between the car and the segment.

[0003]

The tail seal technique for the rectangular shield is an extension of the tail seal technique for the circular shield, but has the following problems. <B> The tail brush on the straight line has a pressing force (tightening force).
Is inferior to that of the circular shield, and the tail brush is reversed due to the uneven tail clearance and the injection pressure of the backfill material, and the sealing purpose cannot be achieved. <B> Tail brushes with uneven tightening force are subject to wear and damage, and the backflow material that has backflowed hardens, resulting in a decrease in waterproofness, wasting tail grease, and increasing water from the tail section. , Hinder excavation work. <C> The tail brush, which is worn or damaged, or whose water blocking performance is deteriorated, causes various problems such as having to be replaced in the mine.

[0004]

SUMMARY OF THE INVENTION The present invention has been conceived in view of the above-mentioned conventional problems, and provides a tail seal structure of a shield in which the tail brush does not reverse and the water blocking performance does not decrease. The purpose is to A further object of the present invention is to provide a shield tail seal structure in which replacement work in a mine is minimized. The present invention is
It is intended to achieve at least one of the above objects.

[0005]

In order to achieve the above object, the shield tail seal structure of the present invention comprises:
A shield tail seal structure that is attached along the inner circumference of a tail portion of a shield and seals a clearance between the inner circumference of the tail portion and the outer circumference of the segment while the tip portion slides on the outer circumference of the segment, The main body of the tail seal is composed of a wire brush, the wire brush is sandwiched between an outer protective plate and an inner protective plate, and an intermediate protective plate and a wire mesh are interposed in the wire brush.

The shield tail seal structure of the present invention is characterized in that the outer protection plate and the inner protection plate are provided in a plurality of structures.

Further, in the tail seal structure of the shield of the present invention, an intermediate protective plate is interposed on the base end side of the tail seal,
The wire mesh is interposed on the tip side.

Further, the tail seal structure of the shield of the present invention is characterized in that the wire mesh is a stainless wire mesh.

Further, the shield tail seal structure of the present invention is characterized in that a plurality of tail seals are attached at intervals.

Further, the wire brush of the shield tail seal structure of the present invention is characterized in that it is formed to have a sufficient length to have a tightening margin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The case where the tail seal structure of the present invention is used for a circular shield will be described, but the tail seal structure of the present invention can also be used for a rectangular shield or an elliptical shield for excavating a rectangular tunnel.

<A> Shield excavator FIG. 1 is a schematic configuration diagram of the shield excavator 1. A cutter head 11 for cutting the natural ground 7 on the face of the face is provided at the tip of the shield machine 1 and a skin plate 14 is connected to the rear of the cutter head 11. A drive device 16 and a control device for the cutter head 11, a device for discharging excavated sediment, and the like are provided in a front portion of the work space covered with the skin plate 14.
An assembly facility for the segment 6, a shield jack 13 and the like are provided in the rear part. The segment 6 composed of a plurality of arc-shaped blocks is circumferentially assembled inside the rear side (tail plate 15) of the skin plate 14 to form a ring-shaped lining body. Press the shield jack 13 against the tip surface of the assembled segment 6 to remove the reaction force,
The ground plate 7 is excavated by the cutter 12 on the front surface while sliding the skin plate 14 with respect to the segment 6.

Since the segment 6 is assembled inside the skin plate 14, a gap δ is provided between the outer periphery of the segment 6 and the drill hole 17. This gap δ is
It is a space obtained by adding the thickness of the tail plate 15 to the amount of tail clearance that enables the smooth sliding of the skin plate 14 with respect to the segment 6. The void δ is filled with a backfill material such as a backfill mortar from the inside of the tunnel to prevent the surrounding ground 7 from collapsing due to the existence of the void δ. The injected backfill material is the skin plate 14 (or the tail plate 1).
5) through the tail clearance between the segment 6 and the inside of the shield machine 1 must be prevented. Therefore, a tail seal 2 is provided at the rear end of the tail plate 15 in order to prevent backfill material, ground water, muddy water, etc. generated by excavation from entering the shield machine 1.

<B> Tail seal The tail seal 2 is attached along the entire inner circumference of the tail plate 15 of the shield machine 1, and the tip end of the tail seal 15 slides on the outer circumference of the segment 6 while the tail seal 15 is attached. The clearance between the inner peripheral portion and the outer peripheral portion of the segment 6 is sealed. The main body of the tail seal 2 is a wire brush 21 made of a metal wire having a long bristle, and both sides of the wire brush 21 are sandwiched between a flexible inner protection plate 22 and an outer protection plate 25. An intermediate protective material 23 and a wire mesh 24 are provided inside. The wire net 24 is, for example, a stainless wire net having elasticity and wear resistance. The tip portion of the wire brush 21 has an inner protective plate 22 and an outer protective plate 2
It projects from 5. Inner protection plate 22 and outer protection plate 25
For example, a spring steel such as a leaf spring is formed into a strip shape, and the wire brushes 21 are sandwiched by being arranged in the circumferential direction. The root portions of the inner protective plate 22 and the outer protective plate 25 with the wire brush 21 sandwiched therebetween (the base end portion of the tail seal 2) are tied with a binding band 3 and further covered with a fixing plate 4. Tail plate 15
The fixing plate 4 is joined by welding or the like to the mounting ring 5 fixed to the inner peripheral surface of the tail seal 2, and the tail seal 2 is attached to the inner peripheral surface of the tail plate 15.

Two inner protective plates 22 and two outer protective plates 25 are provided.
It has a single-piece structure to improve wear resistance. The intermediate protective material 23 and the stainless wire mesh 24 interposed in the wire brush 21 are attached to the intermediate protective material 23 from the base end side of the tail seal 2, and the stainless wire mesh 24 is attached to the tip of the intermediate protective material 23.
Connect. Since the stainless steel wire mesh 24 is located on the tip side, wear resistance is improved. By interposing the intermediate protective material 23 and the stainless wire mesh 24, the wire brush 21
Form a plurality of layers. In this example, two sheets of the intermediate protective material 23 and the stainless steel wire net 24 are interposed, but the number of the interposed particles is a design matter and can be appropriately selected.

It is preferable that the tip portion of the wire brush 21 composed of a plurality of layers is divided to form a step, and the stress applied to the tip portion is distributed and dispersed. Since the wire brush 21 is sandwiched between a plurality of flexible inner protection plates 22 and outer protection plates 25 and the wire brush 21 is formed of a plurality of layers by the intermediate protection material 23 and the stainless wire mesh 24, the tail seal 2 Has excellent resilience when the load is removed and has durability against repeated loads.

The tightening margin of the tail seal 2 will be described with reference to FIG. The tail seal 2 has an angle α of approximately 40 to 50 degrees with respect to the inner peripheral surface of the tail plate 15 (see FIG. 2).
Attached), and is formed with a sufficient length to have a tightening allowance. For example, the distance t between the outer peripheral surface of the segment 6 and the inner peripheral surface of the tail plate 15 is 70
The length of the tail seal 2 is about 30 mm.
By forming from 0 mm to 350 mm, the tightening margin S1 can be 200 mm to 260 mm at the assembly position T1 of the segment 6. By forming in this way, even if the segment 6 is maximally depressed (maximum depression position T2), the interference S2 can be 170 mm to 220 mm. In the rectangular shield construction method, most of the tail seal 2 is a straight line portion,
The pressing force (tightening force) of the tail seal 2 is inferior to that of the circular shield, but the structure of the present invention can sufficiently cope with it.

The tail seal 2 is arranged in the order of the tail seals 2A, 2B and 2C from the excavation direction A in front of and behind the tail seal 2A, 2B and 2C.
It is attached to the tail plate 15 in steps. The length of the third-stage tail seal 2C is made longer than that of the other tail seals 2A and 2B, and most of the external fluid such as backfill material and groundwater is blocked by the third-stage tail seal 2C. . In addition, tail grease or the like is filled between the tail seals 2A, 2B and 2C.

Next, the function of the tail seal 2 will be described. As the shield machine 1 is propelled in the direction A of excavation, the assembled segmented segment 6 is left behind the tail plate 15. Between the segment 6 and the natural ground 7, muddy water or groundwater exists as an external fluid, or a backfill material such as mortar is injected. Here, the tail seal 2 is provided on the tail plate 15 so as to seal between the tail plate 15 and the segment 6 as described above, and the shield machine 1
The external fluid is prevented from entering the inside of the or segment 6.

Front and rear three-stage tail seals 2A, 2B, 2C
Constitutes the tail seal 2 as a whole, and the tail seal 2C has a natural ground 7 at a portion behind the outer protective plate 25.
A backfill material such as mortar is injected into the space δ between the segment 6 and the segment 6. Since the length of the third-stage tail seal 2C is longer than that of the other tail seals 2A and 2B, most of external fluid such as backfill material and groundwater is blocked by the third-stage tail seal 2C. . The external fluid that slightly invades does not enter the shield excavator 1 because it is blocked by the second-stage and first-stage tail seals 2B and 2A.

Thus, the excavation in the excavation direction A is continued while preventing the external fluid from entering the inside of the shield machine 1. The entire tail seals 2A, 2B and 2C act as springs and are strongly pressed against the segments 6, and even if the distance (tail clearance) between the tail plate 15 and the segments 6 is partially different, reliable sealing can be performed. it can. Therefore, the large section tunnel construction method (MM
It is possible to sufficiently seal even with a large tail clearance when a slide steel plate is carried on the back as in the ST method). Further, the shield machine 1 may return (backing) in the direction opposite to the direction A of excavation, but the tail seal 2 is flexible and can be dealt with.

In the tunnel construction in the shield machine 1 as described above, during the curve construction in the up, down, left and right directions, by controlling the excavation direction of the shield machine 1 as shown in FIG. An angle is generated in the center line direction X2 of the segment lining assembled inside, and the rear end of the segment lining is biased in any of the circumferential directions within the tail clearance (the distance between the tail plate 15 and the segment 6). Become. According to the tail seal 2 of the present invention, it has a sufficient restoring force when a large load is removed, so that the bias is absorbed by the elasticity of the tail seal 2 and the tail seal 2 does not reverse.
Curved construction is possible within the allowable absorption range.

As described above in detail, in the present invention, both sides of the wire brush 21 are sandwiched by a plurality of flexible inner protective plates 22 and outer protective plates 25, and the intermediate protective material 23 and the stainless wire net 24 are provided inside. By interposing
It has a sufficient restoring force, enhances the water blocking effect, and is less likely to cause water leakage than the conventional tail seal as a whole. Therefore, even when the external fluid has a high pressure, the water stopping property can be exhibited. Therefore, the additional injection of tail grease becomes unnecessary, and the injection amount can be significantly reduced. Further, since it is possible to dig a long distance without replacing the wire brush 21, it is economical, and the construction period of the entire shield construction can be shortened. Further, in the present embodiment, the tail seals 2 are provided in the front and rear three stages in the order of the tail seals 2A, 2B and 2C, but it is also possible to provide only arbitrary stages.

[0024]

Since the present invention is as described above, the following effects can be obtained. <B> The tail seal has a structure that has a sufficient restoring force when a large load is removed, so that the water blocking effect is enhanced and water from the tail portion can be eliminated. <B> Since the wire brush has an intermediate protective material and a stainless wire mesh, and both sides are sandwiched by a plurality of outer protective materials and inner protective materials, it is possible to sufficiently resist the injection pressure of the backfill material and the tail seal is reversed. There is no. Therefore, there is no backflow of the backfill injection material, and it is possible to eliminate the adverse effects caused by the curing of the injection material. <C> Since the wear resistance is improved by interposing the stainless wire mesh, the consumption of the tail grease is reduced and the number of times the tail brush is replaced in the mine is reduced. Therefore,
Since it is possible to dig a long distance without exchanging the tail seal, it is economical, and the entire construction period of the shield work can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a shield excavator.

FIG. 2 is an explanatory view showing a tail seal structure of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a tail seal and a segment.

FIG. 4 is an explanatory view showing a state during curve construction.

[Explanation of symbols]

1 ... Shield excavator 14 ... Skin plate 15 ... Tail plate 2 ... Tail seal 21 ... Wire brush 22 ... Inside protection plate 23 ... Intermediate protection plate 24 ... Wear resistant member 25 ... Outside protection plate 6 ... ・ Segment

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiaki Okubo             11-11 Kitahamacho, Chita City, Aichi Prefecture Ishikawajima Harima             Heavy industry Aichi factory (72) Inventor Masayuki Araike             11-11 Kitahamacho, Chita City, Aichi Prefecture Ishikawajima Harima             Heavy industry Aichi factory (72) Inventor Katsumi Kadota             11-11 Kitahamacho, Chita City, Aichi Prefecture Ishikawajima Harima             Heavy industry Aichi factory F-term (reference) 2D055 BA01 BB01 JA06

Claims (6)

[Claims] 1. A tail seal structure for a shield, which is attached along an inner peripheral portion of a tail portion of a shield, and a tip portion slides on an outer peripheral portion of a segment to seal a clearance between an inner peripheral portion of the tail portion and an outer peripheral portion of the segment. The main body of the tail seal is a wire brush, the wire brush is sandwiched between an outer protective plate and an inner protective plate, and an intermediate protective plate and a wire mesh are interposed in the wire brush. , Shield tail seal structure. 2. The tail seal structure for a shield according to claim 1, wherein the outer protection plate and the inner protection plate have a plurality of structures. 3. The shield tail seal structure according to claim 1 or 2, wherein an intermediate protective plate is provided on the base end side of the tail seal, and the wire mesh is provided on the tip end side. The tail seal structure of the shield. 4. The shield tail seal structure according to claim 1, wherein the wire net is a stainless wire net. 5. The shield tail seal structure according to claim 1, wherein a plurality of the tail seals are attached at intervals. 6. The shield tail seal structure according to any one of claims 1 to 5, wherein the wire brush is formed to have a sufficient length to have a tightening margin. Tail seal structure.