JP3492924B2 - Shield excavator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when constructing a small diameter tunnel lining portion and a large diameter tunnel lining portion on a tunnel excavation wall surface excavated by a shield excavator, segments of these large and small diameter tunnel lining portions. The present invention relates to a shield excavator capable of excavating while taking a propulsion reaction force according to a diameter.

[0002]

2. Description of the Related Art When excavating a tunnel with a shield excavator, for example, for soft ground where groundwater or the like exists, a large-diameter, thick-walled segment is constructed along the tunnel excavation wall surface to withstand earth pressure. In the case of ground with a small soil water pressure, a thin wall segment with an outer diameter smaller than the above large diameter segment is constructed and solidification of mortar etc. is made between the outer peripheral surface and the tunnel excavation wall surface. Tunnel linings are constructed by filling materials.

As a concrete method for constructing such large and small diameter tunnel linings by a shield excavator, for example, an inner tail having a certain thickness is mounted in the tail portion of the shield excavator, and the inner circumference of the inner tail is mounted. Assemble small-diameter segments sequentially along the surface ゝ Install a small-diameter tunnel lining of a specified length on the front end surface of the small-diameter segment while taking the propulsion reaction force of the propulsion jack, and remove the inner tail when installing a large-diameter segment. Segments with an outer diameter larger than the small diameter segment are sequentially assembled along the inner peripheral surface of the tail part, and a predetermined length along the tunnel excavation wall surface while applying the propulsion reaction force of the propulsion jack to the front end surface of this segment. The method of constructing a large-diameter tunnel lining part is adopted.

[0004]

However, according to the above method, the tunnel lining having the same internal space and the different outer diameter, that is, the large and small diameter tunnel covering by the segments having the same inner diameter and different thickness. Even if construction is possible, there is a wide (large diameter) space part with a large inner diameter segment and a narrow (small diameter) space part with an outer diameter smaller than the inner diameter of the large diameter segment. It is difficult to construct continuously. That is, in the case of segments having different thicknesses as described above, since the front end faces of these segments overlap on the circumference of the same diameter, the spreader attached to the rod end of the propulsion jack is the front end of any segment. It can be pressed against the surface to take propulsion reaction force,
In the case of a large-diameter segment and a small-diameter segment whose outer diameter is smaller than the inner diameter of this large-diameter segment, the front end faces of these large-small-diameter segments are separated in the radial direction without overlapping and the front end face of one segment This is because if the rod end of the propulsion jack can be abutted, it cannot be abutted on the front end face of the other segment.

The present invention has been made in view of the above problems, and a large-diameter tunnel lining portion composed of large-diameter segments and a small-diameter tunnel covering composed of a segment having an outer diameter smaller than the inner diameter of the large-diameter segment. It is an object of the present invention to provide a shield excavator which can be constructed by using the same propulsion jack on the front end face of these large and small diameter segments while applying a propulsive reaction force to the working part.

[0006]

In order to achieve the above object, the shield excavator of the present invention sequentially assembles segments in a skin plate, and installs the segments on the front end face of the assembled segment along the inner peripheral surface of the skin plate. A shield excavator configured to excavate a tunnel by abutting a plurality of propulsion jacks arranged in the circumferential direction, the shield excavator comprising :
Attach an annular fixing plate to the inner surface of the kin plate.
The swing fulcrums are set at predetermined intervals in the circumferential direction of this fixed plate.
And one end is attached to the swing fulcrum and the other end
The arm member supporting the propulsion jack to the center of the turning fulcrum.
It is displaced in the inward and outward directions in accordance with propulsion jacks are moved inward and outward in the radial segments by the turning drive means as heart
Is configured.

The shield excavator according to claim 2,
The invention according to (1) is characterized in that the swivel fulcrum is formed by a propulsion jack fixed to the outer peripheral portion of an annular fixing plate.

[0008]

[Operation] When constructing a small diameter tunnel lining on the excavated tunnel excavation wall while excavating the tunnel with the shield excavator, the annular inner tail member can be separated beforehand in the tail portion of the skin plate of the tunnel excavator. The small diameter segments are sequentially assembled along the inner peripheral surface of the inner tail member. Then, the propulsion jack provided in the skin plate is translated inward to a position where the axial center of the rod faces the front end face of the small diameter segment.

In this state, the rod of the propulsion jack is extended and its end face is pressed against the front end face of the small-diameter segment assembled in the inner tail member, and a propulsive reaction force is applied to this front end face to extend the rod for shield excavation. The small diameter segment is sent to the excavation wall surface side while the machine is excavated, and the excavation wall surface is lined. By repeating this work, a small-diameter tunnel lining part is constructed by the small-diameter segments that are sequentially connected along the tunnel excavation wall surface. The space formed between the tunnel excavation wall surface and the small diameter segment is filled with a solidifying material such as mortar, and the tunnel excavation wall surface is lined with a small diameter tunnel lining portion through a solidified layer of this solidifying material. .

In this way, after the small diameter tunnel lining portion of the desired length is constructed on the tunnel excavation wall surface to be excavated while the tunnel excavator is being advanced, when the tunnel excavator reaches the construction position of the large diameter tunnel lining portion, the skin is cut off. The inner tail member connected to the tail portion of the plate is separated from the tail portion and an annular reaction force receiving segment member is assembled in the skin plate, and the outer peripheral portion of the rear surface of the reaction force receiving segment member is used as the inner tail member. The inner peripheral portion is connected to the front end face of the small diameter segment so as to face each other.

On the other hand, the propulsion jack mounted in the skin plate is translated outward to a position where the axial center of the rod faces the front end face of the large diameter segment assembled along the inner peripheral face of the skin plate. Let In this state, first, by pushing the rod end of each propulsion jack against the front surface of the outer peripheral portion of the reaction force receiving segment member and extending it, the tunnel excavator is excavated, and the inner tail member along with the small diameter segment at the forefront is advanced in accordance with the excavation. Send it to the wall surface of the tunnel excavation.

After that, the rod of the propulsion jack is contracted to assemble a large-diameter segment for one ring along the inner peripheral surface of the skin plate in the space between the rod and the reaction force receiving segment member. The tunnel excavator is propelled by pressing and extending the propulsion jack against the front end face of the diameter segment. Furthermore, each time a tunnel excavator excavates a certain length, a large-diameter segment for one ring is sequentially assembled along the inner peripheral surface of the skin plate and is connected to the large-diameter segment that was assembled first, and is sent out to the rear, The diameter segment lining is constructed.

In this way, by translating the propulsion jack arranged in the skin plate inward,
By supporting the propulsion reaction force on the front end face of the small-diameter segment and constructing a small-diameter tunnel lining part, and by translating it in the outward direction, the propulsion reaction force is supported on the front end face of the large-diameter segment and the large-diameter segment is supported. It is intended to perform the construction of the tunnel lining section, the driving means into and out direction of propulsion jacks, upper
The slewing fulcrums are provided at predetermined intervals in the circumferential direction on an annular fixing plate that is integrally provided on the inner peripheral surface of the skin plate, and the arm member is swiveled inward and outward by expanding and contracting a jack or the like around each slewing fulcrum. In this way, the propulsion jacks mounted and supported on the tip of each arm member are displaced in and out.

Further, as described in claim 2 , the swivel fulcrum is formed by a propelling jack different from the propelling jack that swivels in and out, and the propelling jack is formed on the front end surface of the large diameter segment. If it is provided on the outer peripheral part of the above-mentioned annular fixing plate facing each other, when constructing a large diameter tunnel lining part, when the small diameter segment is constructed on the front end face of the large diameter segment where the circumference of the end face is longer than the small diameter segment With this, a large-diameter tunnel lining section can be constructed by pressing a large number of propulsion jacks.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a concrete embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a large-diameter tunnel lining portion A is constructed, and then the large-diameter segment lining portion A is continued. FIG. 3 is a simplified vertical sectional side view of a shield excavator T that is constructing a small-diameter tunnel lining section B.
Is the cutter head 21 at the front end of the opening of the skin plate 1.
Is rotatably arranged, and a tail seal 22 is attached to the inner peripheral surface of the rear end portion of the tail portion 1a of the skin plate 1 over the entire circumference. Further, there is a certain distance in front of the tail portion 1a. The outer peripheral end surfaces of the annular front and rear fixing plates 2 and 3 are integrally fixed to the inner peripheral surface of the skin plate 1 with a small space in the front-rear direction.

As shown in FIGS. 2 and 4, a plurality of pairs of left and right propulsion jacks 4 and 4 are arranged at predetermined intervals in the circumferential direction on the front and rear fixing plates 2 and 3, and each pair of propulsion jacks 4 and 4 is arranged. There is provided a drive means including a swing drive jack 5 for simultaneously swinging the propulsion jacks 4 and 4 inward and outward of the front and rear fixing plates 2 and 3. A mechanism for displacing and moving the propulsion jacks 4 and 4 inward and outward by the operation of the turning drive jack 5 will be described. As shown in FIGS. 3 and 4, the front and rear fixing plates 2 and 3 communicate with each other on the same center line. The center holes 6a and 6b are provided at predetermined intervals in the circumferential direction, and the center holes 6 corresponding to the front and rear are formed.
The fixed propulsion jack 7 is inserted into a and 6b, and the flange portion 7a fixed to the outer peripheral surface of the rear end of each fixed propulsion jack 7 is fixed to the rear fixing plate 3 with a bolt, and the left and right sides of each fixed propulsion jack 7 are fixed. As shown in FIG. 2, the front and rear fixing plates 2 and 3 on one side are provided with arc-shaped guide holes 8a and 8b which are long in the radial direction of the front and rear fixing plates 2 and 3 with the fixed propelling jack 7 as the center.

Further, the base end portions (outer end portions) of the pair of left and right arm members 9a and 9b are rotatably supported at the central portions of the fixed propelling jacks 7 projecting forward from the front side fixing plate 3. A pair of left and right propulsion jacks 4 and 4 are supported by the tip portions (inner end portions) of these arm members 9a and 9b in a fitted state, and rear portions of the propulsion jacks 4 and 4 are provided with the left and right guide holes. Fixed propelling jacks 7 are inserted into 8a and 8b, respectively, so as to be movable inward and outward, with the fulcrum as a fulcrum.

Further, a cylinder chamber 10 which is long in the radial direction of the front and rear fixing plates 2 and 3 is formed between the facing surfaces of the front and rear fixing plates 2 and 3 inside each fixed propulsion jack 7 and slides in the cylinder chamber 10. A long hole in which a piece 11 is slidably mounted and a front fixing plate 2 facing the cylinder chamber 10 communicates with the schilling chamber 10.
A small-diameter shaft 11 formed by projecting 12 and protruding on the front end surface of the sliding piece 11
a is projected forward through the long hole 12, and the small diameter shaft 11a
The inner ends of the pair of left and right connecting rods 13a and 13b are rotatably connected to the protruding end of the connecting rods 13a and 13b, and the outer ends of these connecting rods 13a and 13b are connected to the central portions of the pair of left and right arm members 9a and 9b. The turning drive jack 5 is connected between one arm member 9a and the support piece 2a projecting forward from the inner peripheral end of the front side fixing plate 2.

Accordingly, when the turning drive jack 5 is expanded and contracted, one arm member 9a turns inward and outward about the fixed propulsion jack 7 and at the same time the other arm member 9a moves.
9b pivots in opposite directions via a pair of left and right connecting rods 13 and 13b and a sliding piece 11 that slides inward and outward in the cylinder chamber 10, and is supported by the tips of these left and right arm members 9a and 9b. The left and right propelling jacks 4 and 4 are configured to be moved inward and outward at the same time along the left and right arcuate guide holes 8a and 8b, respectively. Then, when the propulsion jacks 4 and 4 are moved outward, the rods of the respective jacks projecting rearward together with the fixed propulsion jack 7 are assembled into a ring-shaped large-diameter segment member 2a. The front end surface of the small-diameter segment B1 is formed by assembling the rods of the propulsion jacks 4 and 4 into a plurality of small-diameter segment members 2b in a ring shape while being brought into contact with the front end surface of the segment A1. It is configured to abut. As shown in FIG. 2, the fixed plate 2 is provided with a stopper member 31 which is detachably attached via a bolt 32 or the like between the opposed end portions of the central portions of the arc-shaped guide holes 8a and 8b, and the above-mentioned propulsion is performed. When the jack 4 is moved inward and outward, the jack 4 is removed, and after the movement, the jack 4 is attached and the propulsion jack 4 is fixed at that position.

Cutter head 21 of the shield excavator T
As shown in FIG. 1, the skin plate 1 is rotatably supported by a partition plate 23 stretched at the front end portion thereof, and is rotatably driven by an appropriate rotary drive mechanism (not shown). . Further, the space between the cutter head 21 and the partition wall plate 23 is formed in the excavated earth and sand intake chamber 24, of the earth and sand discharge means 25 consisting of a screw conveyor installed in the machine below the earth and sand intake chamber 24. The front end of the opening is faced, and the earth and sand is discharged from the earth and sand discharging means 25 to the outside through a discharge passage such as a discharge pipe.

Reference numeral 26 denotes a backing material injection port formed at a proper position of the skin plate 11, which communicates with an injection pipe 27 which is fixed in the longitudinal direction of the outer peripheral surface of the skin plate 11. The backing material 14 is injected from the rear end of the opening toward the tunnel excavation wall surface t excavated by the tunnel excavator T.

In FIG. 1, the small-diameter tunnel lining portion B is constructed on the excavated wall surface t while excavating the tunnel by the shield excavator T, and subsequently the large-diameter tunnel lining portion B is constructed. It shows a state in which the small-diameter tunnel lining portion B is being constructed again after the construction of the small-diameter segment lining portion A after the construction of the large-diameter segment lining portion A. The space between t and t is filled with the solidified material layer C, the inner diameter of the large-diameter tunnel lining portion A is larger than the outer diameter of the small-diameter tunnel lining portion B, and the outer peripheral surface thereof is excavated. It is constructed so as to be along the wall surface t.

In such a method of constructing the large-diameter tunnel lining portion A and the small-diameter tunnel lining portion B, when the small-diameter tunnel lining portion B is constructed, the rod of the turning drive jack 5 is contracted so that The arm members 9a, 9b are swung inward about the fixed propulsion jack 7, and the propulsion jacks 4 supported by the tip portions of these arm members 9a, 9b,
By moving 4 along the left and right circular arc guide holes 8a, 8b to the inner ends of the guide holes 8a, 8b at the same time, the tips of the rods of these propulsion jacks 4, 4 correspond to the front end face of the small diameter segment B1. Displace to the position. On the other hand, the tail portion of the skin plate 1 behind the propulsion jacks 4 and 4.
As shown in FIG. 5, an annular inner tail member 15 having a constant thickness is formed on the inner peripheral surface of 1a so that the width in the tunnel length direction is larger than the width in the tunnel length direction of the small diameter segment B1 for one ring. To the inner surface of the tail 1a
It connects so that it can be separated via.

In this state, a plurality of small-diameter segment members curved in an arc shape along the inner peripheral surface of the inner tail member 15 are assembled into an annular shape, so that the outer peripheral surface of the inner tail member 15 is formed.
After forming a ring-shaped small-diameter segment B1 that slidably contacts the tail seal 17 attached to the inner peripheral surface of the, and connecting the small-diameter segment B1 to the front end of the already-assembled small-diameter segment B1, the inner tail By pushing the rod end of the propulsion jack 4 against the front end surface of the small diameter segment B1 assembled in the member 15 to extend the rod, a propulsive reaction force is applied to the small diameter segment B1 to advance the shield excavator T.

As the shield excavator T excavates, the small-diameter segment B1 in the inner tail member 15 is pushed toward the tunnel excavation wall surface t side while sliding its outer peripheral surface into the tail seal 17 attached to the inner tail member 15. When the outer peripheral surface of the front end portion of the small-diameter segment B1 is fed to the position where it slidably contacts the tail seal 17, the shield excavator T is stopped to contract the rod of the propulsion jack 4, and the front end surface of the small-diameter segment B1 is again formed. After assembling the small diameter segment B1 for one ring along the inner peripheral surface of the inner tail member 15, the rod is extended and sent to the tunnel excavation wall surface t side.
The small-diameter segment B1 is successively sent to the excavation wall surface t side every time the tunnel excavator T excavates a constant-length tunnel portion to form a small-diameter tunnel lining portion B having a desired length.

Since the small-diameter segment B1 is assembled along the inner peripheral surface of the inner tail member 15 when the small-diameter tunnel lining B is formed, when the small-diameter segment B1 is sent to the excavation wall surface t side, A ring-shaped space is formed between the outer peripheral surface of the small-diameter segment B1 and the excavation wall surface t. Therefore, every time the small-diameter segment B1 for one ring is pushed to the excavation wall surface t side, the inner tail member 15 is inserted into the space.
Solid material filling hole (not shown) penetrating between the front and rear end faces of the
A solidified material layer C, which is made of a mixture of mortar or cement and a part of excavated earth and sand, is filled and hardened to form a thickened solidified material layer C, and the tunnel excavation wall surface t is covered with the small diameter tunnel covering t. This is a structure in which the engineering department B is built.

When the small-diameter tunnel lining portion B having a desired length is formed as described above and the shield excavator T reaches the building position of the large-diameter tunnel lining portion A, the tail portion 1a of the skin plate 1 and the inside thereof are inspected. Locking metal fitting 16 connecting with the tail member 15
By removing the inner tail member 15 slidably along the tail portion 1a of the skin plate 1 and extending the rod of the turning drive jack 5 to fix the left and right arm members 9a, 9b to the fixed propulsion jack 7. The propulsion jacks 4, 4 supported by the tips of the arm members 9a, 9b are pivoted outwardly about the center, and the left and right circular arc guide holes 8a, 8b are provided.
By moving the guide jacks 8a and 8b to the outer ends of the guide holes 8a and 8b at the same time, the tips of the rods of the propulsion jacks 4 and 4 are displaced to positions corresponding to the front end face of the large diameter segment A1. The fixed propulsion jack 7 is attached to the outer peripheral portions of the front and rear fixed plates 2 and 3 corresponding to the front end face of the large-diameter segment A1, so that all the propulsion jacks 4 moved outward,
4 is in a state of being arranged concentrically with the fixed propulsion jack 7.

In this state, as shown in FIG. 6, the outer diameter becomes the outer diameter of the inner tail member along the inner peripheral surface of the skin plate 1 between the propulsion jack 4 and the front end surface of the inner tail member 15. An annular reaction force receiving segment member 18 having an inner diameter substantially equal to that of the small diameter segment B1 is assembled, and a rear surface of an outer peripheral portion of the reaction force receiving segment member 18 is integrally connected to a front end surface of the inner tail member 15 and an inner periphery thereof. The rear surface of the part is brought into contact with or brought close to the front end surface of the small diameter segment B1 without being connected.

Then, the reaction force receiving segment member 18
After pushing the rod ends of the propulsion jacks 4 and 7 against the front surface of the outer periphery of the propulsion jack 4 and extending the propeller jacks 7, the reaction force receiving segment member 8 exerts a propulsion reaction force to excavate the shield excavator T for a certain length, and then the propulsion jacks 4 and 7. 7 is contracted to assemble a plurality of large-diameter segment members annularly along the inner peripheral surface of the skin plate 1 in the space between the rod end and the outer peripheral front surface of the reaction force receiving segment member 18. By assembling a large-diameter segment A1 for one ring by means of the above, the rear end surface of the large-diameter segment A1 is integrally connected to the front surface of the outer peripheral portion of the reaction force receiving segment member 18 by a bolt, and then propelled to the front end surface of this large-diameter segment A1. By pushing the jacks 4 and 7 to extend the shield excavator T, the large-diameter segment A1 is relatively moved to the tunnel excavation wall surface t side together with the reaction force receiving segment member 18 and the inner tail member 15. Move to.

When the rear portion of the large-diameter segment A1 is sent out from the skin plate 1 to the tunnel excavation wall surface t side, the shield excavator T is stopped and the rods of the propulsion jacks 4 and 7 are contracted, and again one ring worth. After assembling the large-diameter segment A1 along the inner peripheral surface of the skin plate 1 and connecting the large-diameter segments A1 and A1 to each other, the rods of the propulsion jacks 4 and 7 are extended to excavate the shield excavator T and to increase the large diameter. The segment A1 is sent to the tunnel excavation wall surface t side. At this time, the backing material injection port 26 provided in the skin plate 1 is provided in the gap between the large diameter segment A1 extruded along the inner peripheral surface of the tunnel excavation wall surface t as the shield excavator T excavates and the excavation wall surface t. The backing material 14 is injected from the above through the injection pipe 27 to provide a backing material layer. In this way, the large-diameter segment A1 is sequentially connected for each excavation of the tunnel of a constant length of the shield excavator T and is sent to the excavation wall surface t side to form the large-diameter tunnel lining portion A of a desired length. .

After the construction of the large-diameter tunnel lining portion A, to move to the construction of the small-diameter tunnel lining portion B again, the propulsion jacks 4 and 4 are displaced inward and, as shown in FIG. After connecting the outer peripheral rear surface of the reaction force receiving segment member 18 of the same size and the same shape as the reaction force receiving segment member 18 to the rear end surface of the diameter segment A1 by bolts, the inner peripheral surface of the tail portion 1a of the skin plate 1 Assemble a new annular inner tail member 15 along with the inner tail member 15 by attaching the inner tail member 15 to the tail portion 1a.
A state in which the rear end surface of the small-diameter segment B1 assembled along the inner peripheral surface of the inner tail member 15 is abutted on the front surface of the inner peripheral portion of the reaction force receiving segment member 18 without being connected. Then, the rod end of the propulsion jack 4 is pressed against the front end face of the small-diameter segment B1 to extend the shield excavator T.

Thereafter, in the same manner as the construction method of the small diameter tunnel lining portion B described above, the shield excavator T assembles the small diameter segment B1 having the same length as the small diameter segment B1 for one ring and one ring for each advance. While being integrally connected to the front surface of the small-diameter segment B1 previously assembled and slidably contacting with the tail seal 17 of the inner tail member 15, the shield excavator T sequentially pushes it toward the excavation wall surface t side and the excavation wall surface t. The space between the small-diameter segment B1 and the small-diameter segment B1 is filled with a solidifying material to construct the small-diameter tunnel lining B having a predetermined length. In the above embodiment, the jack is used as the turning drive means, but the present invention is not limited to this, and the turning drive means may be rotationally driven by a motor or manually.

[0033]

As described above, according to the shield excavator of the present invention, the segments are sequentially assembled in the skin plate, and the segments are sequentially arranged on the front end face of the assembled segment along the inner peripheral surface of the skin plate. A shield excavator that supports the thrust of a plurality of propulsion jacks and advances a tunnel and sends a segment to the excavated tunnel excavation wall surface to line the tunnel. Therefore, when constructing a large-diameter tunnel lining part with a large-diameter segment along the tunnel excavation wall surface excavated by a shield excavator, the propulsion jack is placed outward. It can be moved to face the front end face of the large diameter segment and a small diameter tunnel lining with a small diameter segment can be constructed. Even if the outer diameter of the small-diameter segment is smaller than the inner diameter of the large-diameter segment, the propulsion jacks should be moved inward so that the rods of these propulsion jacks reliably face the front end surface of the small-diameter segment. Therefore, the propulsion reaction force of the propulsion jack can be reliably and firmly received by these segments in both large and small diameter segments, so that large and small diameter tunnel linings can be constructed smoothly and efficiently. is there.

Further, fixing a fixing plate annular the inner peripheral surface of the skin plate provided fulcrum circumferentially to the fixed plate at predetermined intervals, supports the propulsion jack tip around a revolving fulcrum Since the propulsion jacks are moved inward and outward by rotating the arm members with the revolving drive jacks, the propulsion jacks supported at the tips of all the arm members can be quickly and accurately formed into small-diameter segments. Depending on the large diameter segment, it can be displaced to a position facing the front end faces of these segments.

Further, according to the invention of claim 2 ,
The swivel fulcrum is provided on the outer peripheral portion of the fixed plate, and the swivel fulcrum is formed by a propulsion jack that is different from the propulsion jack that swivels in and out, so when constructing a large-diameter tunnel lining part, It is possible to increase the number of propulsion jacks to be pressed against the front end face of the large-diameter segment whose end face has a longer circumferential length than the small-diameter segment, and to efficiently construct the large-diameter tunnel lining portion.

[Brief description of drawings]

FIG. 1 is a simplified vertical sectional side view of a shield excavator that is constructing a tunnel.

FIG. 2 is a front view of a fixed plate provided with a propulsion jack,

FIG. 3 is an enlarged vertical side view of a part thereof,

FIG. 4 is a vertical sectional front view thereof,

FIG. 5 is a simplified vertical side view showing a state where a small-diameter tunnel lining is being constructed,

FIG. 6 is a simplified vertical cross-sectional side view showing a state where construction of a large-diameter tunnel lining portion has started.

[Explanation of symbols]

1 skin plate 2, 3 annular fixing plate 4 propulsion jack 5 Jack for turning drive 7 fixed propulsion jack 8a, 8b circular guide hole 9a, 9b Arm member T shield excavator A1 Large diameter segment B1 small diameter segment Large diameter tunnel lining section B Small diameter tunnel lining section t Tunnel excavation wall

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshinori Asahi 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka City Okumura Gumi Co., Ltd. (56) References JP-A-8-93381 (JP, A) (58) Survey Areas (Int.Cl. ⁷ , DB name) E21D 9/06 E21D 11/08

Claims (2)

(57) [Claims] 1. A tunnel is formed by sequentially assembling segments in a skin plate, and abutting a plurality of propulsion jacks circumferentially arranged along an inner peripheral surface of the skin plate on a front end surface of the assembled segment. a constructed shield excavator to excavation, of the skin plate
An annular fixing plate is fixed to the peripheral surface.
A fulcrum is provided at every predetermined interval in the direction.
, One end is attached to the turning fulcrum and the other end is equipped with a propulsion jack.
Swing drive of the supported arm member around the swing fulcrum
A shield excavator characterized in that the propulsion jack is configured to be moved inward and outward by means to displace the propulsion jack inward and outward according to the diameter of the segment. 2. A fulcrum is characterized by a propulsion jacks secured to the outer periphery of the fixed plate of an annular claim 1
Shield excavator described in.