JPS6217070B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an enlarged tunnel excavation method and its apparatus, and more particularly to an enlarged tunnel excavation method and apparatus for excavating an enlarged tunnel in the middle of a normal tunnel.

In this type of conventional expansion excavation method, a vertical hole is excavated from the ground in the area planned for expansion in a normal tunnel excavated by a primary shield excavation machine with a normal diameter.
It was common practice to widen the normal diameter tunnel. However, the above-mentioned construction method has drawbacks such as the difficulty of securing a place to excavate a vertical hole in the recent overcrowded ground conditions, and the need to backfill the excavated vertical hole after completing the widening work. Improvement was desired.

Therefore, in Japanese Patent Application No. 56-153966 (Japanese Unexamined Patent Publication No. 58-98595), the applicant of this application previously excavated a normal diameter tunnel with a primary shield excavator, and then excavated one end of the planned expansion area of the tunnel. A starting base will be created by partially expanding the excavation, and the expanding shield excavator will be assembled and installed at this launching base, and the expanding shield excavator will be propelled while sequentially removing the primary segments that have already been installed over the entire area scheduled for expansion. We proposed a construction method in which an enlarged tunnel was constructed by enlarging the tunnel and constructing a secondary segment on the inner surface of the widened section.

The purpose of this application is to further improve this construction method, and its gist is to use a primary shield excavator to excavate a tunnel of normal diameter, and when the area to be expanded is reached, a starting base is set up behind the primary shield excavator, and at this starting base, A construction method and device for assembling an expanding shield excavating machine and connecting it to the primary shield excavating machine, and excavating an expanding tunnel while simultaneously advancing the primary shield excavating machine and the expanding shield excavating machine using a propulsion jack of the expanding shield excavating machine. It is.

This improves the previously proposed construction method, which required constructing a single primary segment over the entire area planned for expansion and removing it again during widening work, shortening the construction period and making it more economical. This will further improve the effectiveness of the project.

Embodiments of the present invention will be described below with reference to the drawings. First, as shown in FIG. A diameter tunnel 2 is excavated to one end of the area 3 to be expanded, and a primary segment 4 is applied to the inner surface of the normal diameter tunnel 2.

The primary shield excavator 1 is propelled by extending the jack 1a using the already tensioned primary segment 4 as a reaction force receiver, and after excavating the face, the jack 1a is retracted and the erector device is attached to the inner surface of the tunnel. This is similar to the conventional shield construction method, in which a new primary segment is connected to an already tensioned primary segment for tensioning.

Next, several rings of the primary segment 4 stretched at one end of the area to be expanded 3 behind the primary shield excavator 1 are removed from the inside of the tunnel, and the inner end of the removed ring is marked as shown in FIG. 1B. A circumferential shield excavator 7 is installed in a steel box 6 buried at the bottom of the circumference, and a circumferential shield excavator 7 is installed along the guide ring 5 while extending the jack 7a of the excavator. Perform excavation and build launch base 8. On the inner surface of this starting base 8, inward U-shaped circumferential segments 9 made of steel are installed in succession each time circumferential excavation is performed to prevent the collapse of the ground.
Depending on the soil quality, ground improvement by chemical injection or the like may be performed in the area 10 around the base indicated by diagonal lines.

Next, inside the starting base 8, the
As shown in FIG.
Assemble and install 1.

Next, the front plate 9a of the circumferential segment 9 is removed, and as shown in FIG. Expanding shield excavator 11 while extending the jack 13 one segment at a time as a reaction force receiver.
As shown in FIG.
4 in sequence. This initial propulsion is carried out until just before the sliding contact between the tail seal of the expansion shield tunneling machine 11 and the circumferential segment 9 is released, and then the initial propulsion jack 13 and the temporarily assembled segment 1
Remove 4.

Then, as shown in Fig. 5, a secondary segment 14 is integrally stretched on the inner surface of the circumferential segment 9, and the jack 11a of the enlarged shield excavator 11 is extended using the secondary segment 14 as a reaction force receiver to extend the enlarged shield excavation. While moving the machine 11 forward, the front primary segments 4 are sequentially removed and the secondary segments 14 are connected and added to the enlarged excavation area. Then, when the tip end portion 11b of the enlarged shield tunneling machine 11 overlaps with the rear end of the skin plate 1c of the primary shield tunneling machine 1, both shield tunneling machines 1 and 11 are connected together, and the primary segment 4 and the secondary segment 14
A reinforcing reaction force receiver 15 using diagonal members is installed between the two. The connecting portion 16 of both shield tunneling machines 1 and 11 is
An enlarged view of the skin plate 1c on which the tail seal 1d on the rear end side of the primary shield tunneling machine 1 is attached, as shown in an enlarged view of the connection part in FIG. 6A and in FIG. The skin plate 11c on the front end side of the shield tunneling machine 11 is superimposed on both sides of the adjustment plate 17, and the backing plates 18 are provided on both sides, and the mounting bolts 19 that pass through these are screwed into the nuts 20 to join them together. be done.

Both the shield tunneling machines 1 and 11 integrally joined in this way use the jack 11a on the side of the expanding shield tunneling machine 11 as a propulsion device for the expansion planned area 3, and the reinforcement reaction force receiver 15 and the secondary segment 1.
4 to simultaneously advance while taking the reaction force, excavate a tunnel of normal diameter with the cutting edge part 1b of the leading primary shield excavator 1, and then the enlarging shield excavator 11 that follows.
This peripheral area is widened at the cutting edge portion 11b. Then, the erector device 12 sequentially stretches the secondary segments 14 on the inner surface of the expanded tunnel that has been excavated, and when the construction of the expanded tunnel for the entire area of the planned expansion area 3 is completed, the expanded shield is sent from the primary shield excavator 1. The excavator 11 is removed and dismantled.

Further, when a normal diameter tunnel is to be subsequently excavated, the primary shield excavator 1 is propelled by the jack 1a in the same manner as described above.

According to the construction method and equipment of the above embodiment, since the primary shield excavator 1 and the expansion shield excavator 11 advance simultaneously, there is no need to extend the primary segment over the entire area to be expanded. However, there is no need to remove it.

Further, the blade opening 1b of the primary shield excavator 1 is positioned in front of the blade opening 11b of the enlarged shield excavator 11, and after excavating a normal diameter tunnel, the surrounding area is subsequently expanded and excavated. This makes it suitable for excavating in clay or silty soil.

As described above, according to the construction method and device of the present invention, the expansion shield excavation machine assembled at the expansion part for the starting base provided at one end of the area to be expanded is integrally connected to the primary shield excavation machine, and the shield This involves constructing an enlarged tunnel while simultaneously advancing the excavator.

Therefore, unlike the conventional method of digging a vertical hole from the ground during widening work, there is no need to be restricted by ground conditions or backfill the vertical hole after widening work, and it is possible to use the normal diameter tunnel proposed earlier by the applicant. Unlike the construction method in which the primary segments, which are installed in advance and expanded over the entire area to be expanded, are sequentially removed during the excavation, expanding excavation is carried out without installing secondary segments. It is possible to further improve work efficiency.

[Brief explanation of the drawing]

The drawings all show embodiments of the present invention, and FIG. 1 is an explanatory diagram showing the construction state of the expansion part for the starting base, FIG. 2 is an explanatory diagram showing the assembled state of the expansion shield excavator, and FIG. 5 and 4 are explanatory diagrams showing the initial excavation state, and FIGS. 5 and 6 are explanatory diagrams showing the connected state of the primary shield excavation machine and the enlarged shield excavation machine. Explanation of symbols, 1...Primary shield tunneling machine, 2...Normal diameter tunnel, 3...Expansion planned area, 4...Primary segment, 5...Guide ring, 6...Steel box,
7... Circumferential shield excavator, 8... Starting base, 9... Circumferential segment, 10... Base surrounding area, 11... Expanding shield excavator, 12... Erector device, 13... Initial propulsion jack, 14... Temporary assembly segment, 15...
Reinforcement reaction force receiver, 16... Connection part, 17... Adjustment plate, 18
...Backing plate, 19...Mounting bolt, 20...Nut.

Claims (1)

[Scope of Claims] 1. While excavating a normal diameter tunnel with a primary shield excavator, an enlarged part for a starting base is provided when the area to be expanded is reached, and the enlarged shield excavator is assembled within the enlarged part, and the enlarged shield excavator is assembled into the primary shield excavator. connect,
An expansion tunnel excavation method characterized in that an expansion tunnel is excavated while a primary shield excavation machine and an expansion shield excavation machine are simultaneously advanced using a propulsion jack of the expansion shield excavation machine. 2 Consists of a primary shield excavator that excavates a tunnel of normal diameter, and an enlarged shield excavator that excavates an enlarged tunnel, and the enlarged shield excavator is detachably attached to the primary shield excavator, and A shield excavator characterized in that the shield excavator is mounted so that the blade opening of the shield excavator is positioned forward of the blade opening of the enlarged shield excavator.