JPS6217069B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for enlarging and excavating the outer periphery of an already excavated normal diameter tunnel, and in particular, a device for enlarging and excavating a tunnel, which is capable of arbitrarily enlarging and excavating by varying or eccentrically enlarging the diameter of the enlarged excavation. It is related to the device.

The shield method is often used as an excellent construction method for tunnel excavation for subway construction and underground cable burying work, but when building subway stations or connecting underground cables, it is often necessary to use the shield method. It becomes necessary to enlarge the section.

The conventional method for carrying out the above expansion work is as follows:
Generally, a shaft was dug from the ground in the area where the tunnel was to be expanded using the shield method, and this shaft was used to construct the expanded tunnel. However, in recent years, it has become increasingly difficult to carry out the implementation due to restrictions on various types of above-ground and underground structures, especially in urban areas, and the cost has also increased due to the fact that the shafts that have been excavated have to be backfilled, except for a portion, after expansion work. There was also a problem.

Therefore, the present applicant previously proposed in Japanese Patent Application No. 56-153966 (Japanese Unexamined Patent Publication No. 58-98595) a tunnel expansion excavation method that improves the above conventional method. This new construction method involves excavating a normal-diameter tunnel using a primary shield machine, then removing the primary segment at one end of the area scheduled for expansion and performing enlarged excavation to construct a starting base, and then assembling and installing the expanded This is a construction method in which a shield machine is propelled in the axial direction along the outer circumference of a normal diameter tunnel, and the enlarged section is constructed by performing widening work while removing the primary segment and attaching the secondary segment to the enlarged excavated section.

The present application proposes an enlarged tunnel excavation device suitable for performing enlarged excavation within a range with a relatively short axial length such as the starting base, and the gist of the present application is as follows.

This is a device that sequentially removes the primary segments of the area scheduled for expansion installed in a normal diameter tunnel and expands and excavates the outer periphery of the primary segment. A circumferential shield machine that excavates the outer periphery in the circumferential direction, and a primary segment at both ends of the planned expansion area that rotatably supports the proximal end side of the circumferential shield machine. 2. A tunnel expanding excavation device, characterized in that the circumferential shield machine has separable upper and lower bodies that are fitted into each other, and a fluid cylinder is installed between the bodies.

As a result, there is no need to provide a vertical shaft when carrying out enlarged excavation, and enlarged excavation can be carried out efficiently in the area to be enlarged by parallel work with normal diameter tunnel excavation. In particular, since the circumferential shield machine can be expanded and contracted in the radial direction using a built-in fluid jack, it is possible to perform enlarged excavation of any diameter concentrically with the normal tunnel, as well as eccentric enlarged excavation. This is a new and effective tunnel expansion excavation device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, embodiments of the apparatus of the present invention will be described with reference to the drawings together with the construction method.

First, as shown in FIGS. 1 and 2, the lower primary segment 3a of the primary segment 3 in the area to be expanded 2, which is formed on the outer periphery of the normal diameter tunnel 1, is removed, and the primary segment 3a in the area to be expanded is removed. The guide ring pieces 5a and 6a on the lower side of the divisible guide rings 5 and 6 that have been installed in advance between the primary segment 3 and the adjacent primary segment 4 outside the planned expansion area are removed. Then, a steel box 7 with a rectangular cylindrical frame is installed in the position of the removed primary segment 3a, and the necessary length is added by pressing it into the ground below with jacks etc. to sink it into the earth and sand inside the steel box. After digging out the base plate 7a and the reaction force receiver 8 are respectively attached as shown in FIG.

Note that the steel box 7 is for retaining the earth, and may be omitted depending on the soil quality of the ground.

Next, as shown in FIG. 4, the base end sides of the circumferential shielding machine A are fitted into the removed guide ring pieces 5a and 6a, respectively, and then each is housed in the steel box 7. Attach the guide ring pieces 5a, 6a to their original positions again.

This circumferential shield machine A has a cutting edge 9 formed at the tip of the propelling side and a propulsion jack 10 built inside, like a general shield machine, and has a substantially U-shaped cross section with an arcuate outer circumferential side. .

In particular, the circumferential shield machine A of the present invention has a machine body that is separably divided into two parts, an upper body 11 and a lower body 12 that are fitted together, and a hydraulic or pneumatic fluid cylinder 1 whose base is pivotally connected to both bodies.
3 and 14 are attached, and the body can be expanded and contracted. That is, when the fluid cylinders 13 and 14 are most retracted, the height of the aircraft body is L ₁ as shown in Figure 4A, and when they are most extended, the height of the aircraft body is L 1 as shown in Figure 4A.
L ₂ , thereby allowing expanded excavation to be performed within the range of L ₁ to _{L 2} in the radial direction.

As mentioned above, the circumferential shielding machine A is rotatably mounted at its proximal end on each guide ring 5, 6 attached to the primary segment 4 located at both ends of the area to be expanded 2, as shown in FIG. steel box 7
The front plate 7b of the shield machine A is removed and the reaction force of the propulsion jack 10 is initially received by the reaction force receiver 8 attached to the rear plate 7c of the steel box to propel the circumferential shield machine A.

Then, while excavating the earth and sand inside the propelled circumferential shield machine, a circumferential segment 15 having an arcuate outer circumferential side and a U-shaped cross section is installed in the space behind the shield machine created by the forward movement. are fixed to the guide rings 5 and 6, respectively. After that, the reaction force is sequentially received by the newly installed circumferential segments 15 in place of the reaction force receiver 8, and the circumferential shield is guided by each guide ring 5, 6 while sequentially removing the inner primary segment 3. The machine A is propelled along the outer periphery of the normal diameter tunnel 1 to carry out a desired enlarged excavation over the entire circumference.

For example, when enlarging excavation in a concentric circle with the normal diameter tunnel 1, it is sufficient to propel the body of the circumferential shield machine with the fluid cylinders 13 and 14 at a desired constant height.

Also, as shown in Fig. 6, the center O ₁ of the normal diameter tunnel 1
Expanding tunnel 1 of an eccentric circle centered on O ₂
6, set the fluid cylinders 13 and 14 to the maximum height L ₁ at the bottom of the drawing, which is the minimum excavation diameter, and set the fluid cylinders 13 and 14 to the maximum height L 1 at the top of the drawing, which is the maximum excavation diameter. The height of the machine body is extended to L ₂ , and excavation is carried out while increasing or decreasing the height of the machine body in the middle part.
In this case, the fuselage height (radial expanded excavation width) L ₂
-L ₁ is made to match the center deviation O ₂ -O ₁ . The above enlarged circumferential shield machine A and steel box 7 after excavation
The rear plate 7c is dismantled and removed, and an enlarged tunnel 16 having a circumferential segment 15 stretched on its inner surface as shown in FIGS. 7 and 8 is constructed. In addition, if it is desired to construct an axially longer expanded tunnel using the expanded tunnel 16 as a starting point, a vehicle propelled in the axial direction along the outer periphery of the primary segment, as previously proposed by the applicant, is inserted into this expanded tunnel. A magnifying shield machine is installed, and the front plate 15 of the circumferential segment is
Remove a and perform enlarged excavation along the direction of the arrow. In the above embodiment, when excavating a normal diameter tunnel, guide rings were attached in advance to the end faces of the primary segments at both ends of the area scheduled for expansion. If it is installed on the inner surface of the segment and the base end of the circumferential shield machine is made to protrude inward, it can be installed during expansion work, so it is not necessary to install it in advance at least when excavating a tunnel with a normal diameter. Therefore, the area to be expanded can be arbitrarily set.

Further, it is also possible to add this guide ring each time the primary segment of the area to be expanded is successively removed along the circumferential direction when performing expansion work.

Furthermore, the circumferential shield machine of the above embodiment is a hollow body with a substantially U-shaped cross section with an open front face on the propulsion side, and is designed to excavate the ground mainly by hand digging.
Similar to the conventional axially propelled shield machine, it is also possible to modify it to an earth pressure type or mechanical digging type.

As mentioned above, the tunnel expansion excavation device of the present application is
By making the circumferential shield machine, which is propelled along the circumference by a guide ring, expandable and retractable in the radial direction, it is possible to create arbitrary expanding tunnels that are concentric with the normal diameter tunnel or eccentrically expanding tunnels as appropriate. It is something that can be excavated.

In addition, in the above embodiment, the eccentric circle was exemplified, but
By adjusting the expansion and contraction of the cylinder, it is of course possible to perform enlarged excavation in concentric circles or ellipses, and it is also possible to perform enlarged excavation in a rectangular shape, although the four corners are gently arcuate.

[Brief explanation of the drawing]

Figures 1, 2, 3, 5, and 6 are process explanatory diagrams showing the enlarged tunnel excavation method;
Fig. 4A is a front view of the circumferential shielding machine of the present invention in a contracted state, Fig. 4B is a front view of the circumferential shielding machine of the present invention in an extended state, Fig. 7 is an end view of the enlarged tunnel in the completed state, and Fig. 8 is a 7 is a sectional view taken along the line -- in FIG. 7. Explanation of symbols: 1... Normal diameter tunnel, 2... Area to be expanded, 3, 4... Primary segment, 5, 6... Guide ring, 7... Steel box, 8... Reaction force receiver, 9...
Blade mouth, 10... Propulsion jack, 11... Upper body, 12... Lower body, 13, 14... Fluid cylinder, 15... Circumferential segment, 16... Enlarged tunnel, A... Circumferential shield machine, L ₁ , L ₂ ... Height of the aircraft, O ₁ , O ₂ ... Center of the tunnel.

Claims (1)

[Scope of Claims] 1. A device for sequentially removing primary segments of an area to be expanded installed in a normal diameter tunnel and enlarging and excavating the outer periphery thereof, wherein a cutting edge is formed on the propulsion tip side, and a built-in propulsion device is provided. A circumferential shield machine that excavates the outer periphery of the normal diameter tunnel in the circumferential direction with a jack, and all of the primary segments at both ends of the area to be expanded, which rotatably supports the proximal end of the circumferential shield machine. The circumferential shield machine includes a guide ring installed concentrically around the circumference, and the circumferential shield machine is characterized in that separable upper and lower bodies are fitted into each other, and a fluid cylinder is installed between the bodies. Tunnel expansion excavation equipment.