JPH0411197A - Tail seal for shield tunneling method using water-impermeable film cover - Google Patents

Abstract

PURPOSE:To prevent a water-impermeable film from being damaged, by forming step parts in several stages in the front end part of a wire brush section on a tail seal which is made into press-contact with the water-impermeable film, around the entire periphery thereof so that the step parts extend in the direction opposite to the excavating direction. CONSTITUTION:A tail seal 1 is arranged around the entire periphery of a shield tail section 12 of a shield machine 10. Then, the front end of the part of wire brush 2 of the seal 1, that is, the part which is made into press-contact with a water-impermeable film is divided into a plurality of front end parts 2A, 2B, 2C, 2D so as to form step parts extending in the direction opposite to the excavating direction of a shield machine. Further, a stress which is exerted mostly to the front end part 2A of the wire brush on the front side of the trail seal 1 as viewed in the excavating direction, is distributed to the other front end parts 2B, 2C, 2D. With this arrangement, it is possible to prevent the water-impermeable film from being damaged.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tail seal for use in a water-impermeable membrane coating shield construction method, and more specifically, the present invention relates to a tail seal for use in a water-impermeable membrane coating shield construction method, and more specifically, a water-impermeable membrane is coated on the outer periphery of a segment to protect it from joints, cracks, etc. of the segment. Impermeable to prevent water leakage! Regarding the tail seal that is most suitable for the coated shield method.

[Prior Art and Problems to be Solved by the Invention] The impermeable membrane coating shield method is described in Japanese Patent Application No. 82-136,97 and No. 82-1488QO, as well as Japanese Patent Application No. 1-1982 filed by the present applicant.
As described in No. 82663, by covering the outer periphery of the segment with an impermeable membrane to prevent water leakage from joints and cracks of the segment, water leakage prevention work called caulking, which is absolutely essential in general shield construction methods, is carried out. This is a construction method that eliminates the need for In addition, Figures 1 and 13 show schematic diagrams of the impermeable membrane coating shield construction method. In Figure 3, IO is the shield machine, 11 is the accumulation membrane device, 12 is the shield tail part of the shield machine IO, and 13 is the water-stop lining. 14 is a segment; 15 is the storage film device 11;
an impermeable membrane coated on the outer periphery of the segment 14 by
Reference numeral 18 indicates that the ground 11 is injected by the water stopping backfilling agent injection device 13
1 is a water-stop backfilling agent injected into the gap between 117 and the segment 14; 1 is a tail seal disposed around the entire circumference of the shield tail portion 12; +8 is a starting shaft;
It is.

The shield tail portion 12 of the shield machine 10 is designed to facilitate ease of movement when making turns or assembling the segments 14, and to improve the shield tail portion 12 whether using a general shield construction method or an impermeable membrane coated shield construction method. Due to the thickness and other factors, the cross-sectional dimension to be excavated is considerably larger than the outer diameter of the segment 14, and a void is created between the segment 14 and the ground 17. If this void is left as it is, the ground will sink, so immediately fill the void between the assembled segment 14 and the ground 17 with a water-stopping agent 16 such as pea gravel or mortar. This prevents ground subsidence. When the water-stopping backfilling agent 16 is injected and filled, there is a risk that the waterstopping backfilling agent 16, ground water, etc. may flow into the shield machine 0 from between the shield tail portion 12 and the segment 14 due to pressure. In order to prevent this inflow, a tail seal 1 is disposed around the entire circumference of the shield tail portion 12.

Tail seals 1 can be roughly divided into two types, rubber tail seals and wire brush tail seals, depending on their materials. However, wire brush tail seals are less watertight than rubber tail seals. Although it is slightly inferior, it is extremely superior in other aspects such as durability, local followability, and ease of replacement, so it is now widely used.

By the way, in the case of the above-mentioned impermeable membrane coating shield construction method, the tail seal 1 does not come into direct contact with the segments 14, but is in pressure contact with the segments 14 through the impermeable* membrane 15 coated on the outer periphery of the segments 14 for sealing. Therefore, in the case of a wire brush type tail seal, the impermeable membrane 15 is easily damaged by the movement of the shield machine 10 as it is propelled during excavation, which not only reduces its durability but also damages it in severe cases. This has the drawback that the water-impermeable membrane 15 may be damaged and the waterproof effect of the water-impermeable membrane 15 is impaired.

[Object of the Invention] Therefore, the object of the present invention is to provide an impermeable membrane coating shield construction method that prevents water-stopping backfilling agent, ground water, etc. from flowing into the shield machine without damaging the impermeable membrane coated on the outer periphery of the segment. Our purpose is to provide tail seals for

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventor has made extensive studies and has arrived at the present invention.

That is, the tail seal for the impermeable membrane-coated shield construction method according to the present invention is arranged around the entire circumference of the shield tail portion of the shielding machine, and from between the shield tail portion and the segment covered with the impermeable membrane. , in a wire brush tail seal for the impermeable membrane coating shield construction method, which prevents water-stopping backfilling agents, etc. that are injected into the gaps between the segments and the ground from flowing into the shield machine, It is characterized in that a wire brush is arranged so that a plurality of steps are formed from the front to the rear in the excavation direction around the entire circumference of the tip of the tail seal that comes into pressure contact.

Further, a preferred embodiment of the tail seal for the impermeable membrane coated shield construction method according to the present invention is: The tip of the wire brush on the front side is brought into pressure contact with the water-impermeable membrane via the synthetic resin sheet, ■ The synthetic resin sheet is a urethane sheet, and ■ The boundary of the step at the tip of the tail seal is water-impermeable. A sheet of substantially the same quality as the membrane is sandwiched and disposed so that the tip of the wire brush rearward from the sheet in the excavation direction comes into pressure contact with the water-impermeable membrane via the sheet.

[Function] According to the present invention, a plurality of steps are formed from the front to the rear in the excavation direction around the entire circumference of the tip of the tail seal that presses against the water-impermeable membrane, so that the front side of the tail seal in the excavation direction is Since the stress that is most applied to the tip of the wire brush can be distributed to each step, even if the pressing force against the tail seal segment is the same, the water-impermeable membrane will not be damaged and the water-stopping property will be improved. can be increased.

Further, a synthetic resin sheet, particularly preferably a urethane sheet having excellent wear resistance, is disposed in close contact with the entire circumference of the tail seal in the forward direction in the excavation direction, so that the tip of the wire brush on the front side in the excavation direction of the tail seal is If it is brought into pressure contact with the water-impermeable membrane through the synthetic resin (urethane) sheet,
Even if the pressing force to the segment is higher, the tip of the wire brush on the front side in the direction of excavation of the tail seal is the part where the load is applied the most, that is, the part where the impermeable membrane is most likely to be damaged.
Since it does not come into direct contact with the water-impermeable membrane, water-stopping properties can be maintained without damaging the water-impermeable membrane.

Furthermore, a sheet of substantially the same quality as the impermeable membrane is inserted at the boundary of the step at the tip of the tail seal, so that the tip of the wire brush at the rear of the sheet in the excavation direction comes into pressure contact with the impermeable membrane through the sheet. In this way, even if there are local irregularities on the surface of the impermeable membrane due to misalignment or missing segments, it will almost completely follow the local irregularities, resulting in high water-stopping properties. Since they are of the same quality, they can almost completely be prevented from being damaged or broken.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view showing one embodiment of a tail seal for an impermeable membrane coating method according to the present invention, FIG. 2 is a schematic sectional view showing another embodiment of the tail seal, and FIG. 3 is a schematic sectional view showing another embodiment of the tail seal according to the present invention. FIG. 2 is a schematic diagram of an impermeable membrane coating method in which a tail seal is used.

In the figure, l is a tail seal mainly composed of a large number of wire brushes 2 bundled together, and is disposed over the entire circumference of the shield tail portion 12 of the shield @10.

3 and 4 are arranged on the front and rear sides of the tail seal 1 in the excavation direction to sandwich and hold the tail seal 1 consisting of the wire brush 2, and also to adjust the angle of the tail seal 1 by the gap between the shield tail portion 12 and the segment 14. It is an armor plate that determines the pressing force to the segment) 14 by setting appropriately. A tail seal 1 consisting of a wire brush 2 sandwiched and held by the armor plate 3.4 is attached to the shield tail portion 12 via a base plate 5 with a fixing device such as a countersunk bolt. Note that it is preferable to insert a wire mesh-like component inside the wire brush 2 of the tail seal 1 to prevent gravel and the like from entering or being mixed in.

Furthermore, the material of the wire brush 2 is not particularly limited as long as it is used as a wire brush tail seal, and its diameter is also not limited, but is preferably 0.3 to 0.4 mm. Further, the length and angle are appropriately determined depending on various conditions during construction, such as the gap between the shield tail portion 12 and the segment 14 described above, the underground pressure, etc.

The tip of the wire brush 2 portion of the tail seal 1, that is, the portion that comes into pressure contact with the impermeable membrane 15 (via the segment 14) is arranged from the front to the rear in the excavation direction of the shield machine 10 as shown in FIG. ! In Figure @3, multiple steps are formed from left to right.

Due to each step, the tip of the two wire brush parts has multiple parts (
In this example, there are four tips 2A and 2B.

It is divided into 2C and 2D. In this way, by dividing the tip portion into a plurality of parts and forming steps, the stress applied most to the wire brush tip portion 2A on the front side in the tail seal excavation direction is reduced to the other tip portions 2B.

Since it can be divided into 2C and 2D, even if the pressure force against the segment 14 of the tail seal 1 is strong enough to damage the water-impermeable membrane 15 if the pressure force does not form a one-step difference, it will not be water-impermeable. High water-stopping properties can be obtained without damaging the membrane 15.

Further, a synthetic resin sheet 6 is disposed in close contact with the entire circumference of the tail seal 1 in the forwardmost direction in the excavation direction, specifically, in the portion between the portion constituting the tip 2A in FIG. 1 and the armor plate 3. ing. The wire brush tip portion 2A on the front side in the direction of excavation of the tail seal by the synthetic resin sheet 6
comes into pressure contact with the water-impermeable membrane 15 through the synthetic resin sheet 6, so even if the pressure contact force on the segment 14 is increased, the area where the load is most applied, that is, where the water-impermeable membrane is most likely to be damaged. Since the wire brush tip portion 2A on the front side in the tail seal excavation direction does not directly contact the water impermeable membrane 15, it is possible to obtain high water-stopping properties without damaging the water impermeable membrane 5.0 Synthetic resin sheet 6 It is preferable to use a urethane sheet which has particularly excellent abrasion resistance.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and as shown in FIG. 2, there are also steps 2A and 2B at the tip of the tail seal 1.

A sheet 7 of substantially the same quality as the impermeable membrane 15 is placed at the boundary between 2C and 2D.
It is preferable to insert and arrange it. Wire brush 2 behind the boundary sheet 7 in the excavation direction (on the right side in Fig. 2)
Since the tip comes into pressure contact with the impermeable membrane 15 through the boundary sheet 7, even if there are local irregularities on the surface of the impermeable membrane 15 due to misalignment or omission of the segments 14, the local irregularities will be removed. Since it can follow almost completely, it has high water-stopping properties, and since it is almost the same as the water-impermeable membrane 15, it can almost completely prevent it from being damaged or broken.

[Effects of the Invention] According to the present invention, the stress that is most applied to the tip of the wire brush on the front side in the tail seal excavation direction can be distributed to the tip of the wire brush other than the frontmost side. Without damaging the impermeable membrane, it is possible to prevent water-stopping backfilling agents, groundwater, etc. from flowing into the shield machine.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a tail seal for an impermeable membrane coating method according to the present invention, FIG. 2 is a schematic sectional view showing another embodiment of the tail seal, and FIG. 3 is a schematic sectional view showing another embodiment of the tail seal according to the present invention. FIG. 2 is a schematic diagram of an impermeable membrane coating method in which a tail seal is used. 1: Tail seal 2: Wire brush part 3.4: Armor plate 5: Base plate 6: Synthetic resin (urethane) sheet 7: Boundary sheet 10: Shield machine 11: Accumulation film device 12: Shield tail part 13: For water stopping Back-filling agent injection device 14: Segment 15: Impermeable membrane 18: Water-stopping back-filling agent] 7: Earth 18 Two-start shaft

Claims (1)

[Scope of Claims] 1. Disposed over the entire circumference of the shield tail part of the shield machine, from between the shield tail part and the segment covered with the impermeable membrane, to between the segment and the ground. In the wire brush tail seal for the impermeable membrane coating shield construction method, which prevents water-stopping backfilling agent, etc. that is injected into the void from flowing into the shield machine, the tip of the tail seal that comes into pressure contact with the impermeable membrane is coated all around the entire circumference. , a tail seal for an impermeable membrane-covered shield construction method, characterized in that wire brushes are arranged so that multiple steps are formed from the front to the rear in the excavation direction. 2. A synthetic resin sheet is closely disposed all around the front of the tail seal in the excavation direction, and the tip of the wire brush on the front side in the excavation direction of the tail seal is pressed against the water-impermeable membrane via the synthetic resin sheet. 2. The tail seal for use in a water-impermeable membrane-coated shield method according to claim 1. 3. The tail seal for a water-impermeable membrane covering shield construction method according to claim 2, wherein the synthetic resin sheet is a urethane sheet. 4. A sheet of substantially the same quality as the impermeable membrane is interposed at the boundary of the step at the tip of the tail seal, so that the tip of the wire brush behind the sheet in the excavation direction comes into pressure contact with the impermeable membrane through the sheet. The tail seal for an impermeable membrane-coated shield method according to claim 2 or 3, characterized in that: