JPH045598Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is designed to reduce the gap that occurs between the starting port of the mine wall and the outer circumferential surface of the shield tunneling machine or segment when the shield tunneling machine is launched from the starting shaft. This invention relates to a sealing device for preventing underground water from gushing into a shaft.

[Prior art and problems] In the shield method, especially the mud pressurized shield method, it is essential to employ a seal device at the starting entrance of the starting shaft.

Conventionally, as a sealing device, a thick annular elastic sealing plate A with pressure resistance in mind, as shown in FIG. 1, has been commonly used.

However, since this seal plate A is usually made of a thick plate of hard natural rubber or synthetic rubber, it cannot be used on the outer peripheral surface of a shield excavator, especially a folding type shield excavator with a step for construction on a sharp curve. Trackability is extremely poor. Therefore, from the gap between the seal plate A and the outer circumferential surface of the shield excavator, highly pressurized water from the ground, highly pressurized mud water, or highly pressurized backfill mortar during shield construction may gush out and the entire amount cannot be stopped. There were many failures. Also,
When a soft-mesh seal plate is used to improve its ability to follow the outer peripheral surface of a shield tunneling machine, there are problems such as poor durability and breakage.

[Purpose of invention]

The object of this invention is to provide a sealing device for a shield starting shaft that can solve the above-mentioned problem and prevent the eruption of groundwater etc. very easily.

[Structure of the idea]

In order to achieve the above object, this invention is an entrance packing that fixes the outer periphery to the front surface of the shaft wall around the starting mouth of a shaft for starting the shield excavator. or an annular seal main plate that slides into contact with the outer peripheral surface of the segment on the rear side in the traveling direction;
It is installed between this main seal plate and the mine wall, is coaxially adhered to the main seal plate, and is attached to the outer periphery of the shield excavator or segment on the side in the excavation direction of the shield excavator from the sliding contact position of the main seal plate. an annular seal auxiliary plate in sliding contact with each other, the main seal plate and the auxiliary seal plate are each formed of an elastic member, and the inner diameter of the main seal plate is smaller than the outer diameter of the shield tunneling machine; The inner diameter of the auxiliary seal plate is smaller than the inner diameter of the main seal plate, and the main seal plate is thicker than the auxiliary seal plate.

〔Example〕

This invention will be explained in detail below using illustrated examples.

In FIGS. 2 and 3, reference numeral 1 denotes a starting shaft, which is composed of a surrounding shaft wall 2.

A starting port 4 is provided in the pit wall 2 at a position for starting the shield excavator 3.

On the front side of the shaft wall 2 in the vicinity of the starting port 4 of the shaft 1, a sealing device 5 serving as an entrance packing is fastened at its outer peripheral edge with bolts 7 or the like via a presser plate 6. The seal device 5 shields the inner diameter of the excavator 3
a pressure-resistant thick annular elastic seal main plate 8 located on the outside so as to have a smaller diameter than the outer diameter of the seal main plate 8; and a thin annular elastic seal auxiliary located on the inside so that the inner diameter is smaller than the inner diameter of the seal main plate 8. The main seal plate 8 and the auxiliary seal plate 9 are coaxially bonded to each other. The main seal plate 8 and the auxiliary seal plate 9 may be made of any material as long as it has elasticity, and natural rubber or synthetic rubber is a good example.

Therefore, in order to launch the shield tunneling machine 3 from the shaft 1, first insert the front part of the shield tunneling machine 3 into the opening of the sealing device 5, and then insert the inner part of the seal main plate 8 of the sealing device 5 into the outer peripheral surface of the shielding machine 3. The peripheral edge and then the inner peripheral edge of the seal auxiliary plate 9 are brought into elastic contact and installed in the starting port 4. After that, the shield excavator 3 is started according to the usual method. That is, the thick pressure-resistant main seal plate 8 comes into elastic contact with the outer circumferential surface of the shield tunneling machine 3, and then the subsequent thin, soft seal auxiliary plate 9 seals the gap that still exists.

Furthermore, as the shield excavator 3 excavates,
The sealing device 5 also applies to the level difference with the segment 10.
Due to its restoring force, the seal is very effectively sealed in the same manner as described above.

Incidentally, it has been confirmed in construction that when a 6 mm thick auxiliary seal plate 9 is bonded to a 25 mm thick rubber seal main plate 8, the outflow of groundwater etc. is significantly reduced.

By the way, when installing the shield tunneling machine 3 in the starting port 4, there is a risk that the thin sealing auxiliary plate 9 may get caught on the outer circumferential bit 11 on the front surface of the shield tunneling machine 3 at its inner peripheral edge and be damaged, so be careful not to slip in advance. Preferably, a material (not shown) is attached or applied. Note that 12 is a floor slab.

[Effect of idea]

According to this invention, the inner peripheral edge of the thick annular elastic seal main plate and the thin annular elastic seal auxiliary plate, which has an inner diameter smaller than the inner diameter of the seal main plate, are coaxially bonded to the outer peripheral surface of the shield tunneling machine. Since the inner peripheral edge of the base is brought into elastic contact with the inner peripheral edge of the
Good workability and work environment can be maintained inside the starting shaft.

[Brief explanation of the drawing]

Fig. 1 is a schematic longitudinal sectional side view of a part of a conventional sealing device fixed to the front side of a shaft wall of a starting shaft, and Fig. 2 is a part of a sealing device fixed to the front side of a pit wall of a starting shaft according to the present invention. FIG. 3 is a schematic vertical side view showing the state of the shield tunneling machine launched from the starting shaft according to the present invention and the seal device fixed to the front surface of the shaft wall of the starting shaft. 1... Starting shaft, 2... Pit wall, 3... Shield excavator, 4... Starting port, 5... Seal device, 6...
... Pressing plate, 8... Annular elastic seal main plate, 9... Annular elastic seal auxiliary plate.

Claims (1)

[Scope of utility model registration request] Entrance packing is an entrance packing that fixes the outer periphery to the front side of the shaft wall near the starting entrance of a shaft to start the shield machine, and this entrance packing is performed on the rear side of the shield machine or segment in the direction of movement. An annular seal main plate that is in sliding contact with the outer circumferential surface, and an annular seal main plate that is installed between this seal main plate and the tunnel wall, is coaxially adhered to the seal main plate, and is closer to the direction of excavation of the shield excavator than the sliding contact position of the seal main plate. and an annular seal auxiliary plate that slides on the outer periphery of the shield tunneling machine or the segment, the main seal plate and the auxiliary seal plate are each formed of an elastic member, and the inner diameter of the main seal plate is the same as that of the shield tunneling machine. The auxiliary seal plate has a smaller diameter than the outer diameter, and the inner diameter of the auxiliary seal plate is smaller than the inner diameter of the main seal plate, and the main seal plate is thicker than the auxiliary seal plate. Seal device for shield launch shaft.