JPH0359238B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The shield construction method of the present invention is suitable for use when excavating tunnels etc. with an elliptical cross section.
Regarding oval shield excavators.

(b) Conventional technology Conventionally, most tunnels excavated by shield excavators have circular cross-sections, and therefore the cross-sections are elliptical (here, "ellipse" is defined in the mathematical sense). Not a strict ellipse, but an ``elongated circle'' that is not a ``perfect circle'' such as an ``ellipse'' or ``unusual ellipse.''
It means. Of course, it also includes a strict "ellipse" in the mathematical sense. ) There were no shield excavators capable of excavating tunnels; most of them had circular cutters attached to a cylindrical shield shell facing in the direction of excavation propulsion.

(c) Problems to be Solved by the Invention However, recently there has been a strong demand for tunnels with elliptical cross sections, and there is a desire for the development of a shield excavator that can excavate such elliptical tunnels using the shield method.

Note that when the cross section is elliptical, the cross-sectional area of excavation is larger than that of a normal circular cross-section, so the corresponding excavation reaction force is also large, accelerating the wear of the cutting bit of the cutter, and causing the cutter to be driven. A large hydraulic motor and excavation jack are also required, but there are many disadvantages to having a large excavation jack and hydraulic motor within a narrow shield. Development is desired.

In view of the above circumstances, the present invention allows tunnels with an elliptical cross section to be easily excavated using the shield method, further reduces the reaction force associated with excavation, reduces wear on the excavation bit, and effectively makes the inside of the shield more effective. The purpose is to provide an elliptical shield excavator that can be used effectively.

(d) Means for Solving the Problems That is, the present invention has an outer shell formed in an elliptical cross section with bulges on both sides when viewed from the front in the excavation direction, and the outer shell A circular cutter is provided at the center of the front in the direction of excavation, and a plurality of screw augers each having a drilling bit formed at the tip are arranged symmetrically along the contour of the outer shell in the swollen portion. The excavation bit of the screw auger is arranged in front of the excavation surface of the circular cutter in the excavation direction, and auxiliary excavation means is provided between the upper and lower parts of the circular cutter and the front end of the outer shell in the excavation direction. It is provided so as to protrude forward from the excavation surface of the cutter, and is provided in such a manner that the outer periphery of the circular cutter is surrounded by the screwer and the auxiliary excavation means.

(e) Operation With the above-described configuration, the present invention functions so that soil can be excavated along the oval shell using the cutter and the screw auger.

Further, the circular cutter that excavates the central part of the face acts to excavate the remaining island-shaped portion that has been excavated in an annular manner by the screw auger and the auxiliary excavation means.

(f) Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a front view showing an embodiment of an elliptical shield excavator according to the present invention, FIG. 2 is a side sectional view of FIG. 1, and FIG. 3 is a sectional view of the screw auger portion.

As shown in FIGS. 1 and 2, the elliptical shield excavator 1 has an outer shell 2 formed in an elliptical cylindrical shape as a whole, and inside the outer shell 2, as shown in FIG. As shown, a bearing member 26 and a shaft member 27 are provided concentrically. A rotary shaft 3d forming the cutter 3 is rotatably supported by the bearing member 26 via a seal member 25, and the rotary shaft 3d is formed into a cylindrical shape so as to surround the shaft member 27. A circular cutter 3 is provided on the left side of the rotation shaft 3d in FIG. A gear 3e formed in an annular shape is provided at the right end of the shaft 3d. In addition, gear 3
Hydraulic motors 23, 23 are engaged with e. In addition, a plurality of screw augers 15 are arranged symmetrically along the outer periphery of the outer shell 2 in the bulged portions 2b, 2b of the outer shell 2 that bulge in the left-right direction in FIG. As shown in FIG. 3, each screw auger 15 is provided in a cylindrical housing 16 provided along the outer wall 2c of the outer shell 2 so as to be rotatably driven by a hydraulic motor 17. A cylindrical sub-housing 16a is provided in the lower part of the housing 16 in FIG. A motor 17 is provided. An auger slide jack 29 is provided between the sub-housing 16a and the housing 16, and by driving the ram 29a of the jack 29 to protrude in the directions of arrows C and B, the screw auger 15 is moved together with the sub-housing 16a.
It can be moved in the directions of arrows C and B. In addition, there is a bit 15 at the tip of the screw auger 15.
A is provided.

Further, each bit 15a corresponds to the excavation surface 3 of the cutter 3.
It is located to the left in FIG. 2, that is, to the front in the excavation direction. Between the screw auger 15 and the outer periphery of the outer shell 2 and the cutter 3 provided in the center,
A fixed blade 5 is provided which is formed in the shape of a sharpening needle and is inclined in the direction of the cutter 3. As shown in FIG. An injection nozzle 6 is provided. As a result, the cutter 3 is surrounded by the screw auger 15 and the fixed blade 5 on the left and right sides in FIG. Therefore, the cutter 3 is surrounded by the screw auger 15 and the fixed blade 5.

In addition, behind the cutter 3, that is, on the right side of Fig. 2, there is a mud water chamber 19 that turns the excavated earth and sand into slurry.
The muddy water chamber 19 is connected to an upper portion thereof with a mud feeding pipe 22 for supplying muddy water, and a lower portion thereof connected to a mud discharge pipe 21 for discharging muddy water. Further, as shown in FIG. 3, the muddy water chamber 19 communicates with the bit 15a at the tip of each screw auger through a mud draining hole formed on the side surface of the housing 16 of each screw auger. A plurality of propulsion hydraulic jacks 9 are provided inside the outer shell 2.
A segment 10 in an assembled state is installed on the right side of the ram 9a of the hydraulic jack 9. An ellipse holding device 11 is provided near the rear end of the outer shell 2 to properly hold and shape the ellipse of the assembled segment 10. Also, number 12
is an erector for assembling the segment 10.

Since the elliptical shield excavator 1 has the above configuration, when the elliptical shield excavator 1 excavates a tunnel 13 having an elliptical cross section, as shown in FIG. Turn the excavation surface 3a of the cutter 3 to the left, rotate the hydraulic motor 23, rotate the cutter 3 via the gear 3e, rotation shaft 3d, and arm 3c, and then drive the hydraulic motor 17 to rotate the screw auger. Rotate 15. Then, the screw auger 15 excavates the face portion corresponding to the bulging portion 2b of the outer shell 2, but at this time, ultra-high pressure water is jetted from the nozzle 6 of the fixed blade 5 toward the face 13a, Blade 5
At the same time, the soil around the cutter 3 is excavated in an oval shape that follows the shape of the outer shell 2. Furthermore, at this time, the auger slide jack 29 is driven to extend the screw auger 15 together with the sub-housing 16a in the directions of arrows B and C in FIG. 3, and to project and retreat.
Then, bit 15 at the tip of screw auger 15
a continuously contacts the face 13a, and together with the action of the ultra-high pressure water from the nozzle 6, the excavation operation of the face portion corresponding to the bulge 2b is performed smoothly. Note that since the cutter 3 excavates the central part of the face 13a in a circular manner, the cutter 3 and the screw auger 1
5. By each excavation operation of the fixed blade 5, the cross section of the face 13a is excavated into an elliptical shape. Also,
As the excavation progresses, the hydraulic jack 9 is driven,
Segment 10 in assembled state via ram 9a
When the outer shell 2 is gradually moved in the direction of arrow A, which is the direction of excavation propulsion, using the outer shell 2 as a foothold, a tunnel 13 with an oval cross section that matches the outer shape of the outer shell 2 is formed. Ru. Also, Screw Auger 1
5 are arranged symmetrically in the bulges 2b, 2b on both sides of the outer shell 2 as shown in FIG.
It is generated evenly on the left and right sides of the front view in FIG. 1, and there is no unbalanced excavation reaction force generated when the outer shell 2 excavates. Furthermore, bit 1 of Screw Auger 15
5a and the fixed blade 5, the face 13a is excavated into a groove shape between the outer periphery of the cutter 3 and the tip of the outer shell 2, as shown in FIG. The portion of the face 13a left behind is excavated. Therefore, the excavation force required to excavate the face 13a of the cutter 3 is small, and the excavation reaction force thereof is also small.

Further, as shown in FIG. 3, the earth and sand 20 excavated by each screw auger 15 is conveyed downward in the housing 16 by the rotation of the screw auger 15, and is formed on the side surface of the housing 16. The mud is transported into the mud room 19 through the mud discharge port,
Therefore, the excavated soil 20 by the cutter 3 is carried out to the outside by the mud removal pipe 21.

Furthermore, since each screw auger 15 is formed with a housing 16 and a mud removal port, the earth and sand excavated by each screw auger 15 can be removed from the housing where the auger 15 is installed without falling and spreading. 16 and sent to the mud chamber 19, it is possible to efficiently recover the excavated soil.

In addition, although the above-mentioned embodiment described the case where there is one cutter 3, the number of cutters 3 is not limited to one, and it goes without saying that a plurality of small-diameter cutters 3 may be arranged in combination. be.

(g) Effect of the Invention As explained above, according to the present invention, the cross section seen from the front in the excavation direction has the bulges 2b and 2 on both sides.
A circular cutter such as a cutter 3 is provided at the front center of the outer shell in the direction of excavation, and the protruding portion is provided with a bit 15a or the like at the tip. A plurality of screw augers 15 each having a bit formed therein are arranged symmetrically along the contour of the outer shell, and the excavating bit of the screw auger excavates more than the excavating surface 3a of the circular cutter. auxiliary excavation means such as a fixed blade 5 is provided between the upper and lower parts of the circular cutter and the front end of the outer shell in the excavation direction in a manner protruding forward than the excavation surface of the cutter; Since the screw auger and the auxiliary digging means are arranged to surround the outer periphery of the circular cutter, the cutter 3 covers the center of the oval outer shell 2, and the screw auger 15 covers the bulges 2b, 2.
Since the part corresponding to b is excavated, both
A tunnel 13 with an oval cross section can be easily excavated using the shield method, and the recent tunnel 1 with an oval cross section
Elliptical shield excavator 1 that can meet the excavation requirements of 3.
It becomes possible to provide

In addition, as shown in Figure 1, the screw auger is placed symmetrically on the bulges on both sides of the outer shell along the contour of the outer shell, so the digging reaction force by the auger is absorbed by the outer shell. The shell is generated evenly on the left and right sides of the front in FIG. 1, so that an unbalanced excavation reaction force is not generated when the shell is dug, and the attitude of the shell can be easily controlled.

Furthermore, since the screw auger and the auxiliary excavation means are provided to surround the outer periphery of the circular cutter, the screw auger's excavation bit and the auxiliary excavation means can cut the face between the periphery of the circular cutter and the tip of the outer shell. It is possible to excavate a trench. Therefore, with the circular cutter, it is only necessary to excavate the part of the face that has been excavated and left behind in the form of an island. Preventing premature wear of the cutter, and further downsizing the excavating jack such as the hydraulic motor and hydraulic jack 9 that drive the cutter,
The space inside the shield can be used effectively.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of an elliptical shield excavator according to the present invention, FIG. 2 is a side sectional view of FIG. 1, and FIG. 3 is a sectional view of the screw auger portion. 1...Elliptical shield excavator, 2...Outer shell, 2b
...Bulge, 3...Katsuta, 15...Screw Auger.

Claims (1)

[Scope of Claims] 1. An outer shell having an elliptical cross section with bulges on both sides when viewed from the front in the excavation direction, and a circular cutter is provided at the front center of the outer shell in the excavation direction. A plurality of screw augers each having a drilling bit formed at the tip thereof are arranged symmetrically along the contour of the outer shell, and the drilling bit of the screw auger is provided in the bulged portion, and the drilling bit of the screw auger is arranged symmetrically along the contour of the outer shell. The auxiliary excavation means is disposed forward of the excavation surface of the circular cutter in the excavation direction, and an auxiliary excavation means is protruded forward of the excavation surface of the cutter between the upper and lower parts of the circular cutter and the front end of the outer shell in the excavation direction. An elliptical seed excavator, wherein the screw auger and auxiliary excavation means surround the outer periphery of the circular cutter.