JPS6126467Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a branch tunnel constructed by the shield construction method etc., which is used to excavate a branch tunnel serving a sewerage branch pipe etc. from the inside of a tunnel lined with segments using a shield machine. This relates to a segment for a tunnel entrance.

Typically, tunnels constructed using the shield method are used for sewerage systems, power and communication wiring pits, subways, and the like. Such tunnels are formed by excavating earth and sand using the shield method and lining the excavated wall with concrete or steel segments. When branching out, the conventional shield construction method involves excavating a vertical shaft from the ground after excavating the tunnel and constructing the required branch tunnel. However, in recent years, it has become extremely difficult to acquire land for shafts and carry out construction work due to worsening road conditions, absolute land shortages, and growing local residents' interest in environmental conservation.

In view of these points, we developed a method of constructing a desired branch tunnel from inside the tunnel without excavating a vertical shaft from the ground.

The present invention has been achieved in that the segments assembled as the tunnel lining to form this branch tunnel are pre-assembled in the area where the branch tunnel is to be formed, so that the shield machine can be started smoothly when forming the branch tunnel. The present invention provides a segment for a branch tunnel entrance.

The embodiments of the present invention will be explained with reference to the drawings: 1
is a normal segment lining the inner surface of a tunnel 3 excavated into the ground 2. 4 is the segment for the branch tunnel entrance of the present invention, and the shield machine 5
In order to excavate a predetermined branch tunnel from the inside of the tunnel 3, the ring is incorporated into a part of the segment ring lined with the segment 1.

This wellhead segment 4 is formed by combining a plurality of segments 4, 4...4, and a circular wellhead forming part 6 is provided in the center thereof to enable the opening of the wellhead to be formed. The surrounding part of the tunnel mouth forming part 6 is made into a residual part 7, and the inner peripheral part of the residual part 7 that joins with the tunnel mouth forming part 6 is made to receive the earth pressure of the ground 2. A horizontally protruding cylindrical rib 9 is integrally provided to reinforce the remaining portion 7, and an annular wellhead packing 8 is provided inwardly around the tip of the rib 9 to form a shield. It is designed to prevent groundwater etc. from flowing into the tunnel 3 when the aircraft 5 takes off.

The wellhead forming portion 6 of the wellhead segment 4 is formed into a circular plate surface 10 with a planar shape slightly larger than the cross section of the shield machine 5, and a short portion is formed on the outer peripheral edge thereof in close contact with the inner peripheral surface of the rib 9 of the remaining portion 7. A cylindrical rib 13 is provided, a bolt 11 is passed through a hole 12 drilled in the rib 9 of the remaining portion 7, and the bolt 11 is detachably fastened to the rib 13 of the wellhead forming portion 6. Further, a divided wellhead forming segment portion 6 forming the wellhead forming portion 6
a, 6b, and 6c have ribs 14 protruding toward the tunnel 3 side on the peripheral edges of adjacent plate surfaces, and the opposing ribs 14, 14 are removably fastened with bolts 16.

On the other hand, the remaining part 7 of the segment 4 is formed into a substantially circumferential shape like a general segment, but the peripheral part in contact with the tunnel entrance segment has a tunnel 3 as described above.
Ribs 9 are provided to protrude inward to form a shaft 18 at the entrance of the branch tunnel, and a flange 20 with bolt holes 19 drilled toward the outer circumference is provided at the tip of the shaft 18. The above-mentioned wellhead packing 8 is attached with bolts 23.

In addition, by positioning the ribs 13 of the wellhead forming part 6 on the inner side of the tunnel 3 along the ribs 9 of the remaining part 7, the plate surface 10 of the wellhead forming part 6 is moved inwardly from the plate surface of the remaining part 7. The concave portion is filled with concrete 24 or mortar with a negative mix.

However, this concrete 24 does not necessarily need to be filled, but may be filled in the same way as in the assembly of the segment ring or during backfilling.
Moreover, if the outer part of the rib 9 of the remaining part 7 is opened in the shape of a bulge 21 and then filled with concrete 24, the concrete 24 can be filled with the inner circumferential surface of the bulge-like widening part when removing the tunnel opening forming part 6 inward. It is possible to make sure that the information is accepted and retained.

FIG. 4 shows another embodiment of the present invention, in which ribs 14, 14 protruding from the divided wellhead forming segment parts of the wellhead forming part 6 are spaced apart from each other as they move toward the tip, and the separated part By inserting wedges 17 and tightening bolts 16, the wellhead forming portion 6 can be easily divided.

To explain the operation of the embodiment configured as described above, first, the remaining portion 7 of the wellhead segment 4 will be described.
The ribs 9 of the wellhead forming part 6, the ribs 13 of the wellhead forming part 6, and the divided parts of the plate surface 10 formed by dividing the wellhead forming part 6 are fastened together with bolts 11 and 14, respectively, to form a segment with the same external shape as the general segment 1. segment, and this segment 4 is incorporated into the planned opening position of the branch tunnel when the tunnel 3 is excavated.

Next, when excavating a branch tunnel with the shield machine 5, the shield machine 5 is installed at a predetermined position in the tunnel 3, and a ring-shaped wellhead packing 8 is attached to the flange 20 at the tip of the cylindrical rib 9 with the presser foot 2.
2 with bolts 23. Thereafter, the bolts 11 and 14 are removed, the wellhead forming part 6 is removed, and the wellhead cylinder body 18 is opened. When the wellhead forming part 6 is filled with concrete 24, the wellhead forming part 6 is filled with concrete 24.
Remove the concrete so that it peels off from the surface 24
is left as is, the shield machine 5 is pushed into the tunnel body 18 through the well head packing 8, the cutter of the shield machine 5 is rotated, and a branch tunnel is excavated while cutting the ground 2 or the negative mix concrete 14. It is something. At this time, the skin plate 25 of the shield machine 5 moves forward by the propulsive force of the jack 26 while slidingly contacting the wellhead packing 8, and the cut concrete fragments and earth and sand are discharged outside the machine by circulating muddy water.

As described above, the present invention provides a branch tunnel portal segment 4 that forms a tunnel entrance for excavating a branch tunnel using a shield machine 5 from within a tunnel 3 lined with the segment 1. It is divided into a formed part 6 and a remaining part 7, and the wellhead forming part 6 is removably connected to the remaining part 7, and a rib 9 is provided around the edge of the wellhead of the remaining part 7.
is provided around the rib 9, and a wellhead packing 8 is provided at the tip of the rib 9.
Since the present invention relates to a segment for a branch tunnel entrance, it has the following various functions and effects.

Since the cylindrical rib is provided around the remaining portion of the tunnel opening segment, the shield machine can be easily started without any additional reinforcement being applied to the segment when excavating a branch tunnel.

Since the wellhead forming part of the wellhead segment is attached by bolts to the ribs provided around the remainder, the wellhead can be opened by simply removing the bolts.

Since the wellhead forming part of the wellhead segment is divided into multiple parts and fastened together with bolts, the wellhead forming part can be easily removed by simply removing the bolts, and the wellhead can be removed by inserting a wedge into the divided part. Removal of the forming part becomes easier.

By filling the tunnel opening forming portion of the tunnel opening segment with concrete, it is possible to prevent earth and sand from flowing into the tunnel until excavation by the shielding machine is performed, and the tunnel can be easily cut by the shielding machine.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a simplified vertical sectional side view showing a state in which a shield machine is installed at the opening position of a branch tunnel in a tunnel, and the wellhead packing is pushed open to face the wellhead segment;
FIG. 2 is a front view showing the wellhead segment installed at the branch tunnel opening position, FIG. 3 is a longitudinal side view of the wellhead segment, and FIG. 4 is a longitudinal side view showing another embodiment of the structure shown in FIG. be. DESCRIPTION OF SYMBOLS 1... Segment, 3... Tunnel, 4... Segment for branch tunnel entrance, 5... Shield machine, 6... Tunnel forming part, 7... Remaining part, 8... Tunnel packing, 9... Rib, 14 ...Rib, 16
...Bolt, 17...Wedge-shaped member, 24...Concrete.

Claims (1)

[Scope of Claim for Utility Model Registration] In the segment 4 for a branch tunnel entrance that forms an entrance for excavating a branch tunnel from the inside of the tunnel 3 lined with the segment 1 by the shield machine 5, the inside of the segment 4 is It is divided into a forming part 6 and a remaining part 7, and the wellhead forming part 6 is removably connected to the remaining part 7,
A segment for a branch tunnel entrance, characterized in that a rib 9 is provided around the edge of the exit of the remaining portion 7, and a exit packing 8 is attached to the tip of the rib 9. The segment for a branch handle wellhead according to claim 1, which is a utility model registered, and wherein a desired wellhead forming portion 6 is formed by combining a plurality of wellhead segments 4a, 4a, . . . . The wellhead forming part 6 is divided into a plurality of parts, and a rib 14 is provided protruding from the periphery of each divided part.
4 are fastened to each other by bolts 16. The segment for a branch tunnel entrance according to claim 1 or 2, which is registered as a utility model. The tunnel opening forming part 6 is recessed into the tunnel 3 from the outer periphery of the segment along the ribs 9 provided around the edge of the tunnel entrance in the remaining part 7, and the recess is filled with concrete 24 of a poor mix to form the tunnel opening segment 4. A segment for a branch tunnel entrance according to claim 1, 2, or 3 of the utility model registration claim, which is formed on the same surface as the outer peripheral surface. Utility model registration claim 1, in which ribs 14 protruding from the periphery of the divided portion of the wellhead forming part 6 are fastened with bolts 16 via wedge-shaped members 17
The segment for a branch tunnel entrance according to item 1, 2, 3, or 4.