JPS61155591A - Tunnel enlarging excavation method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is an enlarged tunnel suitable for constructing an enlarged tunnel part in the middle of an existing tunnel covered with a shield segment humid pipe or concrete, etc. Regarding excavation method.

(Prior Art) As a method for enlarging a part of an existing tunnel covered with shield segments, humid pipes, concrete, etc., there is an enlarged tunnel excavation method already proposed by the applicant.

An outline of this enlarged tunnel excavation method will be explained based on FIGS. 1 and 2.

First, as shown in Fig. 1, an enlarged excavation is performed in the circumferential direction of one end of the area C to be expanded, which is set in the middle of the existing tunnel b, which is covered with a humid pipe and concrete covering a. to form an enlarged part d for the starting base. Thereafter, in order to excavate the outer periphery of the existing tunnel b in order to form an expanded tunnel in the area C to be expanded, an expansion shield excavator e is installed in the expanded portion d.

This expansion shield excavation 11e is constructed by assembling each unit consisting of a propulsion blade e1 and a propulsion jack e2 in a circumferential shape. Next, remove the face plate of the circumferential segment f located in front of the road side of the installed expansion shield excavation machine e, and create a temporary reaction force between the shield excavation machine 11e and the face plate on the rear side of the circumferential segment f. A receiver (not shown) is provided, and when the expansion shield excavation 1fie is advanced a predetermined distance while pushing the jack e2 against the face plate on the extended IICIC side, the cone-shaped reaction force receiver 9 is placed as shown in FIG. It is fixed to the rear face plate of the circumferential segment.

Next, rails h and h are laid in the existing thinnels b located on both sides of the enlarged part d for the transmission base, and the rails h
The frames 1 and 1 are movably mounted on the frames i and h, respectively, and the cutting device 2! is placed between the frames i and i. A girder m, on which an erector l for assembly is movably mounted, is installed on the removal device j and the removal device.

Next, the expansion shield tunneling machine e is attached to a cone-shaped reaction force receiver 9.
is directly subjected to the reaction force of the propulsion jack e2 and propelled by one stroke to perform expanded excavation, and at the same time or after this, the covering soil a in the expansion shield excavator e is cut by the cutting device j and the removal device Nk. At the same time, it is removed, and the segment (7) is stretched on the inner surface of the enlarged excavation part using the assembly erector a. After the segment m is stretched, a reaction force is applied to the segment m, and the expansion shield excavator e is again propelled by one stroke, and the above-mentioned operation is repeated. The above-mentioned work is performed over the entire area C to be expanded to construct the expanded tunnel section n.

(Problems to be Solved by the Invention) According to the above construction method, there are advantages in tunnel construction compared to conventional construction methods, such as eliminating the need for shaft excavation and backfilling work, and easy installation and dismantling of an expansion shield excavator. It has the advantage that the expansion work is extremely efficient and construction costs can be significantly reduced, but work efficiency is poor because there is no scaffolding when excavating at the face of the expansion shield excavation machine or when assembling the secondary segment in the expansion excavation part. There is a drawback that if the covering soil of an existing tunnel is removed too early, the face tends to become unstable.

The object of the present invention is to provide an improved method for excavating an enlarged tunnel without such drawbacks.

(Means for Solving the Problems) The present invention involves excavating a part of the planned expansion area of an existing tunnel in the circumferential direction to form an enlarged part for a starting base of an expansion shield excavator, and a Expansion of the area to be expanded Ii! by installing the expansion shield excavator that excavates the outer circumference of the existing tunnel, and driving the shield excavator along the existing tunnel without tearing down the covering earth of the existing tunnel. The present invention is characterized in that, while excavating, the expanded excavation portion is covered with earth in segments, and the earth covering of the existing tunnel in the area to be expanded at the rear thereof is demolished.

(Example) An embodiment of the present invention will be explained with reference to FIGS. 3 and 4.

As with the construction method proposed earlier, first, one side of the planned expansion area (3) was set in the middle of the existing tunnel (2), which was constructed using the propulsion method and covered with concrete (1). Demolish the soil covering (1) at the end. The exposed surrounding ground corresponding to the demolished portion is expanded and excavated in the circumferential direction to form an enlarged portion for a starting base (4). Thereafter, in order to form an expanded tunnel in the planned expansion area It (3), an expansion shield excavation 1l (5) for excavating the outer periphery of the existing tunnel (h) is installed in the expanded section (4).

This expansion shield excavator (5) is not particularly different from the one used in the construction method proposed on the left.

Next, after forming the enlarged part (4), remove the face plate on the front side of the excavation side of the circumferential segment (6) applied to the outer periphery of the enlarged part (4), and remove the face plate on the front side of the excavation side of the shield tunneling machine (5) and the circumferential segment (6). A temporary reaction force receiver (not shown) is provided between the face plates, and when the expansion shield excavator (5) is advanced a predetermined distance by extending the jack (5b) and pressing the rear face plate, a cone-shaped The reaction force receiver (7) is connected to the circumferential segment (6
) is fixed to the face plate on the reverse side.

Next, an assembly erector device (8) that can be assembled and disassembled is disposed in the expanded portion (4).

This erector device (8) that requires assembly is installed in the existing tunnel (2).
A ring-shaped base (such as an IG) is mounted on the base C10 and has a reincarnated inner ring (9) on the inner circumference so that it can move in the axial direction along the outer circumference of the ring. It consists of an assembly lifter 01 mounted movably in the circumferential direction.

The assembly erector (+1) is, for example, mounted on its fixing base (12).
A pinion (not shown) incorporated in 1 is attached to the base (
Guide rail C fixed along the circumferential direction of the outer peripheral surface of the IG
By meshing with the rack (le provided on the top surface of lID) and rotating the pinion with a motor (41 in the figure), it is possible to move in the circumferential direction.Also, although not shown, a ring-shaped base (IG A motor or the like is used to move it in the axial direction of the existing tunnel (2).

Next, the expansion shield ll1i! The cone-shaped reaction force receiver (n) directly receives the reaction force of the propulsion jack (5b) to propel the advancement (5) for one stroke, performs enlarged excavation, and then attaches an erector for assembly to the inner surface of the enlarged excavation part. Segment qe is stretched by (11). After this tensioning, the reaction force is alternately applied to segment ae again, and the expansion shield excavator (5) is advanced 1iI by one stroke again, and segment 0
Stretch e. Repeating this process, the existing tunnel (2
) is large enough to place the front 2 assembly erector device (8), move the assembly erector device (8) around the outside of the existing tunnel (2) as shown in the third figure. Avoid moving to the surface. Then, the above work will be carried out again in the planned expansion area (3
) repeatedly.

After the expansion excavation of the planned expansion area (3) is completed, the covering earth (1) of the existing tunnel (2) in the planned expansion area (3) is demolished using the breaking device (+71) previously placed in the existing tunnel.

The breaking device 0 is connected to the front 1 body slidably connected to each other.
It consists of 0 arms, and the front body has a hydraulic support jack G! Oa) (20b) protrudes in the radial direction,
There are support jacks (21a) (21b) on the rear fuselage.
) are provided to protrude in the radial direction, and are fixedly supported by the soil covering (1) by abutting the extended supporting jacks on the inner surface of the soil covering (1). Then, install the forward jack ■ between the front fuselage ■ copper support jack (2ob) and the hanging fuselage (+!+1 support jack (21a)),
Extend the supporting jacks (20a) (20b) on the front shell ■ side and press y! When the forward gear is retracted with the support jacks (21a and 21b) on the tn body (191 side) retracted, the rear fuselage ag1 is towed to the front fuselage qe side, and the rear body (1! Dll support jack (21a)
(21b) and support jitter G on the front fuselage [phase] side! 0alG! It can be moved forward by contracting Obl and extending the forward jack. In addition, an arm that can be extended, contracted, and rotated by a jack, a motor, or other means is protruded from the rear hoe body q side, and a) of the rotary cutting R is attached to the tip of the arm (2), and this rotary cutting 1 ( 23a), the soil covering (1) is demolished.

Incidentally, the breaking device a71 is not particularly different from that used in the 12 construction methods previously proposed.

Moreover, various methods such as a flame jet can be employed as a means for demolishing the soil covering (1).

In the above embodiment, the explanation was given as a construction method for enlarging a part of an existing tunnel with a humid pipe or a concrete top, but the present invention can also be applied as a construction method for enlarging a part of an existing tunnel partially covered with earth. Yes, in this case, remove some segments without using the @I9i device.

(Effects of the Invention) The present invention excavates a part of the planned expansion area of an existing tunnel in the circumferential direction to form an enlarged part for a starting base like a shield excavation for expansion, and extends the outer periphery of the existing tunnel to the enlarged part. The expansion shield excavation machine for excavation is installed, and the shield excavation machine is propelled along the existing tunnel without demolishing the covering soil of the existing tunnel to carry out the expansion excavation of the area to be expanded, and at the same time, a segment is created in the expansion excavation part. Since the covering earth of the existing tunnel in the planned expansion area on the rear side is torn down, the existing tunnel can be used as a foothold when excavating at the face of the expansion shield excavation machine or when assembling the secondary segment in the expansion excavation section. This has the effect of improving workability, and since the previously installed tunnel remains when excavating at the face, the face is always stable.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing cutting and spreading excavation, which is one step in the previously proposed construction method, Fig. 2 is a sectional view showing the subsequent process, and Fig. 3 is a sectional view showing one step in an embodiment of the present invention. The cross-sectional view, FIG. 4, is a cross-sectional view taken along line 8-Δ in FIG. (1)...cover soil (2)...l! ! Tunnel construction (3)... Expansion planned area (4)...
Expansion part for starting base (5)...Expansion shield excavation dawn (6)...Circumferential segment (7)...Reaction force receiver (8)...Erector device for assembly (9)...・Wheel (10... Base (+
1)... Erector for assembly (+21... Fixed stand A4
...Guide rail (+51...Rack (1G
...Segment Heman...2 people outside the breaking device

Claims (1)

[Claims] A portion of the area to be expanded in the existing tunnel is excavated in the circumferential direction to form an enlarged part for the starting base of the expansion shield excavation machine, and the expansion shield excavation machine that excavates the outer periphery of the existing tunnel is installed in the enlarged part. The shield excavation machine is installed along the existing tunnel without tearing down the covering soil of the existing tunnel to carry out expansion excavation of the area scheduled for expansion, and the expanded excavation portion is covered with earth in segments, and then the expansion planned area is covered with earth. An expansion tunnel excavation method characterized by demolishing the soil covering existing tunnels in the area.