JP3562663B2 - Shield method - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a shielding method for civil engineering work.
[0002]
[Prior art]
As a shield machine in which the excavated cross section of the shield is a free cross section, there is a so-called eyeglass type shield machine 2 as shown in FIG. 10, in which a plurality of circular cutter disks 1a and 1b are partially overlapped with each other. . In the figure, reference numeral 5 denotes a cutter bit to be implanted on the cutter disks 1a and 1b.
[0003]
[Problems to be solved by the invention]
In such a compound circular shield machine 2, if the ratio of the horizontal width a to the vertical width b is largely changed, the seagull portion 3, which is a non-excavation area between the cutter disks 1, becomes a resistance to excavation, and the thrust increases and the Struggling with directional control. In particular, when the soil is vertically different, direction control is difficult due to the difference in resistance of the seagull portion 3.
[0004]
Further, in the shield construction method using the above-mentioned double circular shield machine 2, even after assembling the segments, a seagull portion 3 as shown in FIG. 11 is generated, and a reinforcing column or reinforcing wall 4 for connecting the seagull portion 3 vertically is necessary. Indispensable, when the outer diameter of the shield is determined, the ratio of a: b cannot be largely changed, so that the total width b is determined.
[0005]
The presence of the reinforcing member 4 restricts the use after the completion of the inner space.
[0006]
An object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example, excavation of any irregular cross section such as eyebrows can be performed without obstruction of thrust increase and direction control, and the completed tunnel is small in diameter. An object of the present invention is to provide a shield method in which a pillar is not required, and a large pillar having no center pillar or a middle pillar can be installed at an arbitrary position by reinforcing the upper and lower parts even in a large diameter.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is a shield machine in which a plurality of circular cutter discs are arranged in parallel, and a shield in which a roller cutter or a roller-shaped cutter having a tool bit attached thereto is arranged in a non-digging area between these cutter discs. machine by applying a cocoon-shaped shield oval with the peripheral linear portion of the tunnel is assembled in a segment of elliptic circular cocoon shield PC steel bars, the assembly segment PC steel wire and other PC material on site The point is to be nervous.
[0008]
[Action]
According to the present invention, a roller-shaped cutter or a roller-shaped cutter having a tool bit attached thereto is arranged in a non-digging area between cutter disks, and the roller cutter or the like is used to cut a plurality of juxtaposed non-digging areas between cutter disks. Continuous planar excavation can be performed. As a result, the completed tunnel after the segment assembly is free of seagulls, and the elliptical eyebrow shield is constructed by assembling PC steel rods, PC steel wires and other PC materials locally on the surrounding linear part and tightening it. It is possible to have a structure without a center pillar, and because of such a structure without a center pillar, the shape of a segment can be made larger per piece.
[0009]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a front view showing one embodiment of a shield machine used in the shield method of the present invention, FIG. 2 is a perspective view of the same, FIG. 3 is a sectional view taken along the line AA of FIG. 2, and FIG. The same components as those in FIG. 14 showing the conventional example are denoted by the same reference numerals.
[0010]
The shield machine used in the present invention is also a double circular shield machine 2 in which circular cutter discs 1a and 1b having a cutter bit 5 implanted are juxtaposed as in the above-mentioned conventional example. In the example shown in the figure, the plurality of cutter disks 1a and 1b are arranged side by side in the front-back direction as shown in FIG.
[0011]
According to the present invention, a roller cutter 6 having a cutter bit planted on a peripheral surface of a rotary drum is disposed in a seagull portion, which is a non-digging area of the cutter discs 1a and 1b, and the outer circumference of the digging locus of the roller cutter 6 is adjusted. It is possible to dig into an elliptical shape, that is, a so-called eyebrow shape as a whole continuously from the outer circumference of the digging locus of the cutter disks 1a and 1b. Instead of the roller cutter 6, a roller-shaped cutter with a tool bit may be provided.
[0012]
The type of the shield machine may be a muddy water type or an earth pressure type, and the diameter and length of the roller cutter 6 may be arbitrarily changed from the center distance of the double circle when the cutter disks 1a and 1b are juxtaposed.
[0013]
The example shown in FIGS. 3 and 4 is a case of a muddy water type as a shield machine. Chambers 7a and 7b are formed on the back side of 1a and 1b, respectively, and a mud feeding pipe 8 and a mud discharging pipe 9 are connected thereto. I do. In the drawing, reference numerals 10a and 10b denote shafts of the cutter disks 1a and 1b. In the case of the earth pressure type, a screw conveyor is provided instead of the sludge pipe 8 and the sludge pipe 9.
[0014]
When excavating with the compound circular shield machine 2 of the present invention in this way, after cutting with the cutter disks 1a and 1b, the mutually non-excavated areas of the plurality of juxtaposed cutter disks 1a and 1b are cut with the roller cutter 6. As a result, the digging area of the roller cutter 6 is continuous with the digging area of the cutter discs 1a and 1b, and the digging can be performed in an elliptical shape, that is, a so-called eyebrow shape as a whole.
[0015]
In FIG. 5, the cutter disks 1a, 1b, 1c, 1d are arranged side by side to be much longer than that of FIG.
[0016]
Next, a description will be given of a case where the segment 14 to be assembled by digging with such a compound circular shield machine 2 is an elliptical cocoon shield of FIG. The cross-sectional shape of the tunnel assembled by the segments 14 has a straight portion 14a in the center of the periphery. As shown in FIG. 6, a PC steel rod 11 is attached along the inside of the straight portion 14a to form a beam. By tensioning at the fixing section 12, a small-diameter central pillar can be made unnecessary.
[0017]
Note that the segments 14 are arranged in a staggered manner in order to expect the effect of the PC steel rod 11 as an additional beam. In addition, prestressing is basically applied after assembling with the PC steel rod 11, but those having a small shape and those capable of being prestressed at the factory are precast at the factory.
[0018]
FIG. 7 shows another embodiment, in which a wire such as a PC steel wire 13 or CFRP (carbon fiber reinforced plastic) is disposed on the straight portion 14a, and the wire is tensioned at the fixing portion 12 in the same manner. With a small diameter, the middle pillar can be made unnecessary.
[0019]
8 and 9 show the case of a large diameter. Even in this case, the PC steel rod 11 is extended along the inside of the straight part and is tightened at the fixing part 12, or a wire such as the PC steel wire 13 or CFRP is used. Is arranged and tensioned by the fixing unit 12, the middle pillar 15 standing between the upper and lower linear portions can be installed at an arbitrary position.
[0020]
【The invention's effect】
As described above, the shield method of the present invention enables excavation of any irregular cross-section such as eyebrows without obstruction of thrust or direction control, and the completed tunnel has a small diameter and a middle pillar. It becomes unnecessary, and even if it has a large diameter, by reinforcing the upper and lower parts and the like, it is possible to eliminate the middle pillar and to install the middle pillar at an arbitrary position.
[Brief description of the drawings]
FIG. 1 is a front view showing a first embodiment of a shield machine used in a shield method according to the present invention.
FIG. 2 is a perspective view showing a first embodiment of a shield machine used in the shield method according to the present invention.
FIG. 3 is a sectional view taken along line AA of FIG. 2;
FIG. 4 is a BB line in FIG. 2;
FIG. 5 is a front view showing a second embodiment of the shield machine used in the shield method according to the present invention.
FIG. 6 is a front view showing a first example of a segment assembly shape in the shield method according to the present invention.
FIG. 7 is a front view showing a second example of an assembling shape of a segment by the shield method according to the present invention.
FIG. 8 is a front view showing a third example of an assembling shape of a segment by the shield method according to the present invention.
FIG. 9 is a front view showing a fourth example of a segment assembling shape in the shield method according to the present invention.
FIG. 10 is a front view showing a conventional example.
FIG. 11 is a front view of an assembled shape of a segment in a conventional example.
[Explanation of symbols]
1a to 1e: Cutter disk 2: Double circular shield machine 3: Seagull section 4: Reinforcement 5: Cutter bit 6: Roller cutter 7a, 7b: Chamber 8: Mud pipe 9: Drain pipe 10a, 10b: Shaft
11 ... PC steel rod 12 ... Anchoring part
13 ... PC steel wire 14 ... Segment
14a: Straight section 15: Middle pillar

Claims (1)

This is a shield machine in which a plurality of circular cutter discs are arranged side by side. An elliptical cocoon-shaped shield using a shield machine in which a roller cutter or a roller-shaped cutter with a tool bit is placed in the non-digging area between these cutter discs A shield method characterized by assembling PC steel rods, PC steel wires and other PC materials locally on a straight portion around a tunnel assembled with the segments of the oval-shaped cocoon shield, and tensioning the segments .

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