JPH0339151B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to an eccentric construction of an existing shield tunnel in an area to be expanded on the outer periphery of an existing shield tunnel, in order to form, for example, a subway station premises or a sewer pipe connection part. This paper relates to an enlarged excavation method for excavating enlarged tunnels.

(Prior art) Conventionally, this type of enlarged excavation method was
As shown in the figure, a shielding machine main body c has a double inner and outer cylindrical structure consisting of an inner cylinder a for guiding and an outer cylinder b for shielding, which are eccentric to each other. Generally, an expanding shield machine f equipped with a plurality of propulsion jacks e is propelled in the axial direction along the outer circumference of an existing shield tunnel g to excavate the outer circumference of the shield tunnel.

(Problems to be Solved by the Invention) The conventional expansion excavation method has a propelling jack e and a blade part d between the inner cylinder a and the outer cylinder b of the shield machine body c of the expansion shield machine f used. Since an installation space or a discharge space for excavated soil must be provided, the inner cylinder a and the outer cylinder b cannot be brought very close together, and therefore an enlarged tunnel with a large eccentricity with respect to the existing shield tunnel g cannot be excavated. This has the following disadvantage.

In order to solve the above-mentioned inconvenience, the present applicant has proposed in patent application 1, which was filed at the same time, that the area of the inner cylinder of the conventional expanding shield machine, which is close to the outer cylinder, is inwardly convex along its entire length along the axial direction. However, it is desired to propose an efficient method for excavating an enlarged tunnel using such an expanding shield machine.

(Means for Solving the Problems) An object of the present invention is to provide an efficient enlarging excavation method that satisfies the above-mentioned requirements. This is an enlarged excavation method for excavating enlarged tunnels, in which a blade is installed on the front side in the direction of propulsion of the shield machine body, which has a dual inner and outer cylindrical structure, consisting of an inner cylinder for guiding and an outer cylinder for shielding, which are eccentric to each other. It has a mouth and a plurality of propulsion jacks along the inner periphery of the outer cylinder, and a region of the inner cylinder that is evenly adjacent to the outer cylinder is convex inward along its entire length along its axial direction. In an expansion excavation method in which an expansion shield machine is propelled in the axial direction along the outer circumference of the shield tunnel to excavate the outer periphery of the shield tunnel, when constructing the existing shield tunnel, a convex part of the inner cylinder of the expansion shield machine is It is characterized in that the corresponding portions are replaced with segments and left unclosed with excavable filler, and the filler is excavated at the same time as the expanding shield machine is propelled.

(Example) An example of the enlarged excavation method of the present invention will be described below with reference to the accompanying drawings.

1 in the figure shows an expansion shield machine used in the expansion excavation method of the present invention, in which a plurality of shield machine division units 2 each having a substantially fan-shaped cross section are assembled into a donut shape with bolts, etc., and a guiding inner cylinder 3 and a shield are eccentric to each other. A fixed cutter-type cutting edge part 6 is provided along the inner circumference of the edge in the direction of propulsion of the main body, and the blade is A propulsion jack 7 is provided for each splitting unit 2 at the rear of the mouth 6, and the two shield machine splitting units 2 in the area where the inner cylinder 3 and outer cylinder 4 of the main body 5 are close are connected to the inner cylinder. It was designed to convex inward so as to move away from the sides. Instead of the fixed cutter, the blade mouth portion 6 may be configured to include a rotary cutter, a muddy excavation device, or the like between the inner cylinder 3 and the outer cylinder 4 of the shield machine body 5.

Reference numeral 8 in the figure indicates an existing shield tunnel, and when constructing the shield tunnel 8, the expansion shield machine 1
The portion of the inner cylinder 3 corresponding to the convex portion 10 is replaced with a segment 11, and is filled with an excavable filler 12 such as poorly mixed mortar and sealed. In addition, a reinforcing member 14 is interposed between the segments 11 at both ends of the portion of the existing shield tunnel 8 to be filled with the filling material 12 by using brackets 13 provided in advance on each segment 11 at both ends. The filler 1 is applied to the back side of the reinforcing member 14 through a filler injection pipe 15 that penetrates the member 13.
I decided to inject 2. At one end of the area to be expanded 9 of the existing shield tunnel 8 constructed as described above, for example, a vertical shaft (not shown) may be excavated or an enlarged shield excavation method previously proposed by the present applicant (Japanese Patent Laid-Open No. 59-21892) may be used. ) by expansion shield machine 1
A launch base is formed, and the expansion shield machine 1 is assembled and installed there.

Next, the expanding shield machine 1 is propelled along the outer periphery of the existing shield tunnel 8 in the axial direction by the propulsion jack 7 while taking the reaction force by a suitable reaction force receiver (not shown). At this time, the blade part 6 of the enlarged shield machine 1 is
While excavating the planned expansion area 9 on the outer periphery of the existing shield tunnel 8, the filler 12 that seals the existing shield tunnel 8 is simultaneously excavated. These excavated soil and filler 12 are discharged to the rear of the expanding shield machine 1 through a space formed between the inner cylinder 3 and the outer cylinder 4 of the expanding shield machine 1. Next, the segment 11 in the inner cylinder 3 of the expanding shield machine 1 is disassembled, and the segment for the expanding tunnel is assembled behind the expanding shield machine 1. Using the segment as a reaction force receiver, the expanding shield machine 1 is further expanded using the propulsion jack 7. It is propelled to excavate the outer periphery of the existing shield tunnel 8. This excavation work is repeated to form an enlarged tunnel eccentrically around the outer periphery of the existing shield tunnel 8.

(Effects of the Invention) According to the present invention, when constructing an existing shield tunnel, the portion corresponding to the convex portion of the inner cylinder of the expanding shield machine is replaced with a segment and sealed with excavable filler, Since the filler material is excavated at the same time as the expanding shield machine is propelled, simply by propelling the expanding shield machine in the axial direction along the outer periphery of the existing shield tunnel, the protruding part of the inner cylinder of the expanding shield machine can be moved into the existing shield tunnel. This has the effect of being able to efficiently excavate an expansion tunnel on the outer periphery of an existing shield tunnel, or an expansion tunnel that is relatively largely eccentric from the shield tunnel.

In the embodiment described above, an example was shown in which the central region of the existing shield tunnel 8 is enlarged and excavated, but it goes without saying that a desired region such as one end region or the entire region of the existing shield tunnel 8 can be enlarged and excavated.

[Brief explanation of the drawing]

Figure 1 is a front view of the expansion shield machine used in the conventional expansion excavation method when it is propelling the outer periphery of an existing shield tunnel, Figure 2 is its - line sectional view, and Figure 3 is the expansion shield machine used in the expansion excavation method of the present invention. Figure 4 is a front view of the expanding shield machine being used when the outer periphery of the existing shield tunnel is being propelled.
The figure is a partially cutaway perspective view showing the construction state of the existing shield tunnel. 1... Magnifying shield machine, 3... Inner cylinder, 4... Outer cylinder, 5
...Shield machine body, 6. Blade opening, 7. Propulsion jack, 8. Existing shield tunnel, 9. Expansion planned area, 10. Convex portion, 11. Segment, 12. Filling material.

Claims (1)

[Claims] 1 An expansion excavation method for excavating an expansion tunnel eccentric to the existing shield tunnel in the planned expansion area on the outer periphery of the existing shield tunnel. A heavy cylindrical shield machine body is provided with a cutting edge on the front side in the propulsion direction, and a plurality of propulsion jacks are provided along the inner circumference of the outer cylinder, and the area of the inner cylinder close to the outer cylinder is In an expansion excavation method in which the outer periphery of the shield tunnel is excavated by driving an expanding shield machine that is convex inward along the entire length of the shield tunnel in the axial direction along the outer periphery of the shield tunnel, the existing shield tunnel When constructing the expansion shield machine, the part corresponding to the convex part of the inner cylinder of the expansion shield machine is replaced with a segment and sealed with excavable filler, and the filler material is excavated at the same time as the expansion shield machine is propelled. Features: Expanded excavation method.