JPH04247197A - Shield machine capable of digging with enlarged diameter - Google Patents

Abstract

PURPOSE:To provide a shield machine, capable of digging with an enlarged diameter, suitably used for constructing a shaft for access for constructing very deep underground railroads, roads, or three-dimensional structure, or for underground connection mutually between very long distance horizontal shield machines. CONSTITUTION:A plural number of spokes 3b and 3c capable of being extended or retracted are attached to the end of a center shaft 4 driven to rotate. Cutter bit support plate 3d and 3c each having a cutter bit 3 are respectively attached to the spokes 3b and 3c. Two pressure resistance partition walls 1b and 1c are arranged side by side in the outer shell 1a of a shield machine. The partition walls 1b and 1c are respectively provided with hatches 5a and 5b for allowing inward and outward passages of persons and materials. The center shaft 4 of the cutter bit 3 is supported for free rotation in the center of the partition walls 1b and 1c. This contributes greatly to the construction of the base of very deep shaft or underground connection in shield construction process.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is applicable to
Expanded diameter suitable for construction of access shafts necessary for constructing roads, railways, or underground three-dimensional space structures at a depth of ~100 m, or underground connection of horizontal shield machines over long distances. Regarding the shield machine capable of drilling.

0002

BACKGROUND OF THE INVENTION In recent years, the utilization of unused underground space, especially deep underground space, has attracted attention, and various technological developments are being carried out. In order to effectively utilize the underground, construction technology for access shaft structures is an important issue. In addition, in long-distance horizontal shield construction, it is known that it is extremely effective to improve construction efficiency by connecting two shield machines that have excavated facing each other underground. (Refer to Japanese Patent Laid-Open Nos. 167895-1989 and 288298-1982).

[0003] At present, closed type muddy water pressurizing shield machines that are effective for constructing deep shaft structures are already known and in use. Regarding existing shielding machines, there are also known shielding machines equipped with a copy cutter device that can excavate an enlarged diameter for the purposes of (a) reducing the shielding machine's propulsion force, and (b) controlling the shielding machine during curved construction. It is also used (Japanese Patent Application Laid-Open No. 62-288298, JP-A No. 63-16
(See Publication No. 7895).

0004

[Problems to be Solved by the Invention] A major problem facing construction technology for deep shaft structures is how to deal with groundwater and groundwater pressure, which increase with increasing excavation depth. Another problem is how to resolve the eventual misalignment of two shield machines that will be connected underground. For the former, it is considered that a treatment method is implemented in which a diameter-enlarging excavation is carried out at the bottom of the shaft, and a large-diameter concrete bottom is built with the necessary and sufficient thickness to stop the groundwater and to strongly withstand groundwater pressure ( (See Figure 5). The latter is a method in which a large-diameter concrete structure is created in advance by expanding the diameter of the underground connection location between the shield machines, and then the center of this concrete structure is hollowed out and a tunnel is penetrated to complete the underground connection. is considered (see Figures 6A and B).

[0005] However, in implementing either method, it is a prerequisite that the necessary and sufficient diameter enlargement is carried out, but at present, there are no concrete methods other than the shield machine equipped with the copy cutter device described above. I don't have the means. The copy cutter device is only capable of expanding the diameter by approximately the same diameter as the outer diameter of the shield machine outer shell, or several tens of centimeters larger than that, and is not suitable for the above-mentioned bottom construction of deep shafts or underground connection method between shield machines. This is a problem to be solved by the present invention because the scale is too small to be applied to the construction of concrete structures carried out in Japan.

[0006]

[Means for Solving the Problems] As a means for solving the problems of the prior art described above, a shield machine capable of drilling an enlarged diameter according to the present invention is rotatably driven as shown in an embodiment in the drawings. A plurality of extendable spokes 3b, 3c are provided in a radial arrangement at the tip of the central shaft 4, and cutter bit support plates 3d, 3e on which a cutter bit 3f is arranged are individually attached to each spoke 3b, 3c. It is characterized by being

Furthermore, two pressure-resistant bulkheads are arranged in parallel on the inside of the shield machine outer shell 1a at substantially right angles to the axis, and each bulkhead is equipped with hatches 5a and 5b through which people or materials can enter and exit, and the bulkhead 1b , 1c, the central shaft 4 of the cutter head 3 is rotatably supported.

[0008]

[Operation] As the spokes 3b and 3c expand and contract, the cutter bit support plate 3d attached to them moves to expand or reduce the diameter of the rotating excavation surface. By the way, the minimum diameter of the rotary excavation surface is about 3 m, and the maximum diameter is about 6 m. By filling and draining water into the diving chamber 1d partitioned into two partition walls 1b and 1c, people and materials can enter and exit from the shield machine side to the face side or vice versa through the respective hatches 5a and 5b. Therefore, it is possible to replace the cutter bit 3, repair the spokes 3b and 3c when they are no longer able to expand and contract, take other troubleshooting measures for the cutter head, or perform various tasks necessary for constructing a base in the expanded diameter excavation section. Make it familiar.

[0009]

Embodiments Next, illustrated embodiments of the present invention will be described. 1A, B, and C briefly schematically illustrate the structure of a shielding machine 1 according to the present invention, and also show states in which the diameter of the cutter head 3 is changed to small, medium, and large. The applied shield machine 1 is of a closed type and pressurizes muddy water. In particular, the cutter head 3 has a structure in which several spokes 3b and 3c are arranged radially at the tip of the central shaft 4, as shown in FIG. 2A or B. Each spoke is 0 to 1 in the radial direction.
The cutter head 3 can be expanded and contracted by about 5 m, and the minimum diameter of the cutter head 3 can be reduced to about 3 m, and the maximum diameter can be expanded to about 6 m. In FIGS. 2A and 2B, 3d is a movable bit support plate attached to spokes 3b and 3c, 3e is a fixed bit support plate, and a large number of cutter bits 3f are regularly arranged on each surface. The central axis 4 of the cutter head 3 is connected to the outer shell 1 of the shield machine.
It is rotatably supported at the center of two pressure-resistant bulkheads 1b and 1c that are arranged in parallel at right angles to the axis on the inside of a. It is said to be configured so that it can move forward and backward. The spokes 3b, 3c of the cutter head 3 are basically configured as a pair of spokes arranged 180° symmetrically as shown in FIG. 2, and in the illustrated example, two pairs (an even number) are provided. Moreover, the amount of expansion and contraction of one pair of spokes 3b is large, and the amount of expansion and contraction of the other pair of spokes 3c is approximately 1
/ It is said to have the second smallest configuration. A fixed bit support plate 3e is attached to the base side of the spoke 3b, which has a large amount of expansion and contraction, and a movable bit support plate 3d is attached to the tip side. Further, a movable bit support plate 3d is attached to the tip side of the spoke 3c, which has a small amount of expansion and contraction. The fixed bit support plate 3e and the movable bit support plate 3d interfere with each other when the cutter head 3 is reduced in diameter to a minimum diameter much smaller than the outer diameter of the shield machine outer shell 1a, as shown in FIG. 2A. It is divided and distributed in a well-balanced manner over the entire rotating excavation surface in an arrangement that does not cause any damage. In addition, when the cutter head 3 is expanded to a maximum diameter that is much larger than the outer diameter of the shield machine outer shell 1a as shown in FIG. A movable bit support plate 3d of 3c and a movable bit support plate 3d of spokes 3b with a large amount of expansion and contraction are arranged in a well-balanced manner over the entire rotary excavation surface. The telescopic structure of the spokes 3b and 3c is usually a telescopic sliding structure divided into a plurality of sections, and a telescopic drive method using a hydraulic jack or the like is adopted. For the rotation of the center shaft 4 and the movement forward and backward in the axial direction, a rotary drive device and a stroke mechanism known for shield machines are employed.

[0010] In order to carry out diameter expansion excavation smoothly and sharply, the bit of the movable bit support plate 3b of the spoke 3b, which has a particularly large amount of expansion and contraction, must be moved on the rotary excavation surface as shown in FIGS. 3A and 3B. In addition to the bit 3f, it is preferable to have a structure in which a bit 3g is also provided on the outer peripheral surface. Next, two bulkheads 1b are installed in parallel inside the shield machine outer shell 1a.
, 1c form two chambers, a face chamber 1f and a diving chamber 1d, and each chamber 1f and 1d
It is possible to independently control its internal hydraulic pressure, and it is also equipped with water injection and drainage equipment and their control equipment. Further, as shown in FIG. 4, high water pressure resistant hatches 5a and 5b, which can be opened and closed, are installed in the two partition walls 1b and 1c in a size and shape that allow for the entry and removal of people or materials.

[0011] Therefore, when the vertical shaft 7 is constructed by using the shield machine 1 described above to reach a deep underground, and the bottom plate construction position is reached, the cutter head 3 is moved as shown in FIG. Expand the diameter and excavate the diameter to a specified bottom thickness (2~
3m). In this diameter-expanding excavation, the amount of muddy water in the face chamber (bottom-expanding excavation part) 1f naturally increases, but the muddy water pressure control mechanism of the shield machine 1 maintains a constant water pressure (5~ 10kg
/cm2). At the stage when the above-mentioned diameter expansion drilling has progressed to a predetermined stroke, the face chamber 1f is opened as necessary.
A flocculant is added to the muddy water inside the tank and stirred well to cause muddy water separation and replacement with fresh water. This ensures good visibility for the diver entering the face chamber 1f. After the fresh water replacement is completed, diving is performed by opening and closing the hatches 5a and 5b of the first bulkhead 1b and second bulkhead 1c of the shield machine 1, and by controlling water injection or drainage and water pressure in the diving chamber 1d partitioned between the two. Let the husband enter the face chamber 1f. Before the diver enters, the cutter head 3 is previously reduced in diameter to its minimum diameter and retreated (raised) to a position as close to the first bulkhead 1b as possible. Then, the cutter head 3 is recovered by a diver disassembling the cutter head 3 and bringing the disassembled parts into the diving chamber 1d. Alternatively, the cutter head 3 can be inserted into the diving chamber 1d through the hatch 5a of the first bulkhead with the diameter reduced to the minimum.
Retrieval may also be carried out by retreating to

After the cutter head 3 is recovered as described above, reinforcing bars and steel frames are brought into the diameter-expanding excavation section as necessary, and reinforcing materials for the bottom plate 6 are installed by assembling them. Note that instead of bringing in a steel frame, the cutter head 3 can be used as a substitute for the steel frame. After installing the reinforcement as described above, the diver returns from the excavation chamber into the shaft 7. Then, the shaft bottom plate 6 is constructed by pouring underwater concrete into the enlarged diameter excavation section using a method of replacing muddy water. As a complete water-stopping means for the shaft bottom plate 6, a shield skin plate 20 constituting the outer shell 1a of the vertical shield machine 1 is configured to be movable about 30 to 100 cm, and is used as a water-stopping plate. That is, as shown in FIG. 5, after pouring underwater concrete in the enlarged diameter excavation section, while the concrete is not yet hardened, the shield skin plate 20 is advanced to penetrate sufficiently deeply into the concrete and solidify. Let it happen. After the concrete of the shaft bottom 6 is completely hardened and completed as described above, the remaining mud in the face chamber 1f is removed, and the main lining is carried out using the outer shell 1a of the shielding machine 1 as a formwork. . In this case, the lower bottom part of the shield segment 8 constructed on the upper part is temporarily supported by a hollow steel pipe and concrete support by operating a propulsion jack. By constructing the main lining with the supporting material involved, construction of the deep shaft 5 approximately 100 m below the ground surface is completed. Thereafter, the pressure inside the first and second bulkheads 1b and 1c is reduced, and the unrecovered main equipment of the vertical shield machine 1, including the cutter head 3, can be dismantled and recovered, and they can be reused. It is.

The shield machine of the present invention can also be suitably applied to horizontal underground joints as shown in FIGS. 6A and 6B. Figure 6A shows the stage where two shield machines 1 and 1, which are to be joined horizontally underground, have approached the position of the joint planned line 10, with a radius of 1 m from the cutter head 3 of the shield machine 1 on the left.
The diameter is greatly expanded by about 1.5 m, and the cutter head 3 is shown in a state in which the cutter head 3 is advanced along the planned line 10 to a stroke that slightly exceeds the position and performs diameter-expanding excavation. This diameter-expanding excavation is a preparation for forming the concrete body 12 in the section of the underground joint. The amount of mud in the expanded diameter excavation section 9 also increases during this diameter expansion excavation, but the mud water pressure control mechanism of the shield machine 1 maintains a constant water pressure and maintains the stability of the ground by changing only the amount of mud while keeping the pressure constant. automatically. The shield machine 1 supports the muddy water pressure with the first partition wall 1b. Thereafter, the cutter head 3 is reduced in diameter to the minimum diameter, and further retreated to be housed within the main body of the shielding machine 1 (inside the outer shell 1a). Next, the diameter of the cutter head 3 of the shield machine 1 on the right side of the figure is expanded, and the cutter head 3 is moved forward by a predetermined stroke to advance the diameter expansion excavation to the position of the planned line 10. As a result, a large hollow diameter enlarged excavation part 9 that completely penetrates the ground is completed. Thereafter, the cutter head 3 is reduced in diameter, moved backward, and housed within the main body of the shielding machine 1. The hollow state of the enlarged diameter excavation part 9 is the same as that of the two shield machines 1.
, 1, its stability is maintained by the pressurized muddy water between the first partition walls 1b, 1b. Note that, depending on the ground characteristics of the underground joint section where the enlarged diameter excavation part 9 is formed, ground improvement by chemical injection method or the like is carried out, for example, in the area 11 surrounded by the dotted line in FIG. 6A, as necessary. The ground improvement 11 is carried out when the stability of the ground at the crown part cannot be ensured under the muddy water pressurization state by the shield machine 1.

[0014] Next, underwater concrete is placed in the enlarged diameter excavation part 9 whose stability is maintained by the pressurized muddy water described above by replacing the muddy water, and the concrete body 12 in the enlarged diameter state is formed as shown in FIG. 6B. form. The water stoppage between the shield machine body and the concrete body 12 is achieved by protruding the water stop plates 20 of the two shield machines 1, 1 and penetrating sufficiently deeply into the concrete 12 before the poured concrete has yet hardened. ensure that Thereafter, when the concrete body 12 has hardened and developed strength, the concrete body 12 is hollowed out and a hole having the same diameter as the horizontal tunnel 13 is penetrated to complete the underground connection.

[0015] Therefore, even if the two shield machines 1, 1 approaching the position of the joint planning line 10 have a positional deviation of about 10 cm, the underground joint can be completed without any hindrance. .

[0016]

[Effects achieved by the present invention] The shield machine capable of excavating an enlarged diameter according to the present invention can greatly contribute to the construction of the bottom of a deep shaft, which is a technical issue in the near future, or the concrete realization of underground joints using the shield method. It contributes.

[Brief explanation of the drawing]

FIGS. 1A, B, and C are schematic illustrations of a shield machine according to the present invention.

FIGS. 2A and 2B are front views of the cutter head section.

FIGS. 3A and 3B are detailed views of the bit support plate.

FIG. 4 is a detailed view of the partition wall.

FIG. 5 is a construction drawing of the bottom of the shaft.

FIGS. 6A and 6B are construction drawings of underground joints.

[Explanation of symbols]

1 Shield machine 4 Central axis 3b spoke 3c spoke 3f cutter bit 3d cutter bit support plate 3e Cutter bit support plate 1a Outer shell 5a Hatch 5b Hatch 3 Cutter head

Claims (2)

[Claims] Claim 1: A plurality of extendable and retractable spokes are provided in a radial arrangement at the tip of a rotationally driven central shaft, and a cutter bit support plate on which a cutter bit is arranged is individually attached to each spoke. A shield machine capable of drilling an enlarged diameter. [Claim 2] Two pressure-resistant bulkheads are arranged in parallel on the inside of the outer shell of the shield machine at substantially right angles to the axis, and each bulkhead is equipped with a hatch through which people or materials can enter and exit. 2. The shield machine capable of excavating an enlarged diameter according to claim 1, wherein the central axis of the cutter head is rotatably supported.