JPH0586795A - Tunnel constructing method - Google Patents

Abstract

PURPOSE:To effectively use a space in a segment as a working area in a tunnel which is constructed by assembling segments in the ground to be excavated within a mountainous district. CONSTITUTION:A tunnel excavating space for receiving therein a part 22b other than a mortar structure part is defined between the ground 20 which has been excavated by a tunnel excavator 1, and a segment 16 which is assembled and with which the ground 1 is covered. A large diameter duct 33 and a small diameter duct 33 which are prolonged in the excavating direction are laid in the part 22b other than the mortar structure. Power, air, water and the like which are required for the tunnel excavation are fed and retrieved through the large diameter duct 32 and the small diameter duct 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a segment built-in type tunnel construction method utilizing the excavated sectional shape of a mountain tunnel.

[0002]

2. Description of the Related Art In the conventional shield construction method, a temporary work wire or the like is arranged in a segment continuously built from the inside of the shield to the rear so as to connect a power source and a face. It was very disturbing when working. By the way, recently, in a rocky ground such as a mountain tunnel, a shield construction method has been proposed to construct a tunnel by building a ring-shaped segment integrally molded in an oval shape in the circumferential direction into the excavation tunnel. It's starting.

[0003]

However, in a mountain tunnel, since the ground is rock, it is excavated in a horseshoe-shaped cross section. Therefore, if a ring-shaped segment is built in the horseshoe-shaped excavated cross section, The diameter is considerably smaller than the excavated cross section diameter. If work wires and ventilation ducts are temporarily installed in the segment of such a small-diameter tunnel as described above, the work space in the segment will be further narrowed, and the segment will be transported, installed, and backfilled. It becomes very difficult to do such work. Therefore, it has been desired to develop a tunnel construction method that can effectively use the space in the segment as a work area by utilizing the excavated cross-sectional shape of the mountain tunnel. In view of the above circumstances, the present invention is
Provide a tunnel construction method that enables the space in a segment to be effectively used as a work area in a mountain tunnel without laying temporary work wire rods or ventilation ducts inside the ring-shaped segment It is a thing.

[0004]

According to the present invention, a natural ground (2) is provided via an excavation work means (1) arranged at a tip portion in the excavation direction.
Tunnel excavation space (250) by excavating 0)
And a segment (16) having a small cross-sectional area with respect to the cross-sectional area of the tunnel excavation space (250) is formed in the tunnel excavation space (250) in a manner subsequent to the excavation work means (1). When constructing the tunnel structure (251) formed by inserting the tunnel structure (251), the duct accommodating portion (22b) into the tunnel excavation space (250), the tunnel structure (251) and the natural ground (20). And a supply / recovery path (32, 33) for power and fluid in the duct accommodating portion (22b), the excavation work means (1) and the tunnel structure (251). Is arranged so as to communicate with the rear side of the. The numbers in parentheses () indicate the corresponding elements in the drawings for the sake of convenience, and therefore the present description is not limited to the description in the drawings. below

The same applies to the column of [Operation].

[0005]

With the above-described structure, the present invention functions so that the power and the fluid are transported through the supply / recovery paths (32, 33).

[0006]

1 is an external perspective view showing an example of a tunnel excavation apparatus used in the present invention, FIG. 2 is a construction side view showing an example of tunnel excavation work, and FIG. 3 is an example of tunnel excavation work. FIG. 4 is a sectional view showing an example of a tunnel constructed according to the present invention.

As shown in FIG. 2, in the tunnel 25 during the excavation, the tunnel excavation device 1 is formed by excavating the natural ground 20 through the cutter head 9, and the tip of the tunnel excavation space 250 in the excavation direction is formed. On the side (arrow A direction side), the cutting blade 9a is arranged so as to face the face 20a, and the oval segment 16 is provided behind the tunnel excavation device 1 in the excavation direction (arrow B direction side). A plurality of tunnel structures 251 are formed by connecting a plurality of them in a line in the directions of arrows A and B without any gap. Tunnel structure 25
The tip portion of 1, namely the end portion of the already installed segment 16 in the direction of arrow A is arranged inside the tunnel excavation device 1 so as to enter from the rear, that is, from the right side in the drawing.

As shown in FIGS. 1 to 3, the tunnel excavation device 1 has an outer shell 2 formed in a barrel shape. The outer shell 2 is close to the excavation direction, that is, the arrow A and B directions. It is composed of a front body 2A and a rear body 2B which are connected to each other in a retractable manner. That is, the relay cylinder 2C is formed at the front end of the rear body 2B so as to enter the rear end of the front body 2A.
The relay case 2C and the relay case 2C are connected by a plurality of outer shell jacks 2D provided along the inner circumference of each other. Then, by pushing and driving the outer shell jack 2D, the front body 2A and the rear body 2B can be separated from the state in which they are in contact with each other by the pitch L3 of the outer shell jack 2D in the directions of arrows A and B. ing. The front torso 2A has an invert 25b continuously extending from the arrow A direction to the arrow B direction.
As shown in FIG. 2, the rear body 2B is formed with a bottom 2B ₁ on the lower side so as to be shielded from the invert 25b. ing. A plurality of outer shell legs 3 are arranged on the left and right inner side surfaces of the front body 2A and the rear body 2B in a line in the directions of arrows A and B so as to be vertically movable so as to project downward from the lower end portions of the front body 2A and the rear body 2B. Therefore, the outer shell leg 3 provided on the rear body 2B penetrates the bottom portion 2B ₁ . Each outer shell leg 3 is supported by the invert 25b, and each outer shell leg 3 is provided with a hydraulic jack 31, a front trunk 2A and a rear trunk 2B.
Is provided so as to be movable up and down, that is, in the directions of arrows C and D. On the outer side of the front body 2A and the rear body 2B, a temporary void 21 'is formed between the ground body 20 and the ground body 2 of the bedrock.
0 occurs in the form of over-digging due to being excavated by the cutter head 9, and the temporary void 21 ′ is provided with the primary backing material 26 made of non-consolidating particulate material such as sand and Styrofoam beads. It is blow-filled.

At the front end portion of the front body 2A, a front sheet pile 5 for temporarily supporting the arch portion of the face 20a is provided.
A plurality of them are provided along the inner periphery of the front body 2A so as to project and retreat in the directions of arrows A and B by a hydraulic jack or the like, and the excavator 6 is installed on the invert 25b inside the front body 2A. .. The excavator 6 has a body 6a, and the body 6a
A hydraulic unit 6 for operating and driving the excavator 6 is provided at the rear part.
1, a control panel 62, etc. are built in. Further, the machine body 6a is provided with a known slide shoe mechanism 7 for propelling and driving the machine body 6a.
Is a pair of ski-shaped slide shoes 7A, 7B that can support the machine body 6a, and are sequentially and intermittently pushed in the direction of arrow A through the slide jack 7C, the toggle jack 13 and the like to drive the excavator 6 to move. It is configured to walk on its own. A cutter head 9 is provided at the front end of the machine body 6a so as to be swingable in the directions of arrows C, D, E and F, and can be moved forward and backward in the directions of arrows A and B and can be swiveled. At the tip of 9, the ground 2
A cutting blade 9a capable of crushing and excavating rocks such as 0 is provided in the shape of a truncated cone. Cutter head shaft 9b
A screw blade 9c is provided on the outer periphery of the so that the rock, that is, the rock of the cutting face 20a crushed by the cutting blade 9a, is conveyed backward in the direction of arrow B, and slipped behind the screw blade 9c. For gathering 10
Are provided so as to be attached to the base portion of the cutter head shaft portion 9b. The shear collected in the gathering 10 is further transported to the rear via the conveyor 11 provided on the side of the machine body 6a, and is transported to the outside of the tunnel 25 by an appropriate shear transport means. Two canopy jacks 12, 1 lined up in the directions of arrows A and B are provided on the upper portion of the machine body 6a.
2 are mounted so that the cylinders 12a are connected to each other, and the front body 2 is attached to the upper portion of each canopy jack 12.
A canopy 12b formed in the shape of a kamaboko along the inner peripheral surface of the canopy portion of A has arrows C and D through a cylinder 12a.
It is provided so that it can be moved and driven in the vertical direction, which is the direction. Side jacks 15, 15 are mounted on the front and rear sides of the fuselage 6a on both sides in the directions of arrows E and F, respectively, so that the fuselage 6a is supported on the inner surface of the front body 2A. The torso 2A is the canopy jack 12,
It is configured such that it can be joined and separated in the inner circumferential direction of the gallery via 12 and the side jacks 15, 15. Inside the side wall portion of the rear body 2B, an erector 17 for lining up the segment 16 in the rear body of the rear body 2B, that is, in the form of continuously joining in the direction of the arrow B, is provided at the upper side in FIG. 1
7a is provided in a fixed form. Erecta 17
A boom 19 for holding and reversing the segment 16
Is provided so as to be swingable in the directions of arrows G and H via the boom jack 191 and movable in the directions of arrows A and B. Further, in the rear body 2B, segment support means 29 for centering the joined segments 16 and 16 are provided in a form fixed to the bottom portion 2B ₁ as shown in FIG.

At the rear of the rear body 2B, as shown in FIG. 4, the tunnel structure 251 is excavated by the excavator 6 so as to have a horseshoe-shaped cross section. The oval segment 16 built in the rear body 2B is formed so as to be arranged. A backfill layer 21 is formed between the segment 16 and the ground 20, and the backfill layer 21 includes:
The mortar 22 is filled through a grout pump 23 shown on the right side in FIG. A transport carriage 30 for loading the newly built segment 16 in a horizontally long state in the segment 16 and transporting it to the position of the erector 17 in the rear body 2B is in the directions of arrows A and B. You can go back and forth. Backfill layer 21
The mortar 22 filled in the mortar structure part 2 is formed by surrounding the outer circumference of the segment 16 with a thickness W1.
2a is formed and the mortar structure portions 22b, 22b shown on the lower left and right in FIG.
2a and the direction orthogonal to the paper surface of FIG. 4 (arrow A in FIG. 2,
It is formed so as to continuously extend in the B direction). Large-diameter ducts 32, 32 made of PVC pipe or the like are laid inside the outside 22b of the mortar structure (left side in FIG. 4), and inside the outside 22b of the mortar structure (right side in FIG. 4). Is a member similar to the large-diameter ducts 32, 32, and the small-diameter ducts 33, 33, 33 having a slightly smaller diameter can be extended in the excavation direction (directions A and B in FIG. 2) through the joint pipe. It has been laid. The ends of the large-diameter ducts 32 and the small-diameter ducts 33 in the direction of arrow A are opened in the outer shell 2, and the ends in the direction of arrow B are extended to the outside of the tunnel 25 to be opened or a suitable device facility. Is selectively connected to. That is, each large-diameter duct 32 is appropriately connected from the inside of the outer shell 2 to a jet fan for exhaust and drainage, a drainage pump facility, etc., and each small-diameter duct 33.
Is properly connected to the inside of the outer shell 2 from an air compressor for air supply, water supply, a water supply pump facility, and the like. In addition, the small-diameter duct 33 accommodates a drive cable as appropriate and selectively,
The drive cable is connected to an equipment such as a generator at a portion of the tunnel 25 extending in the direction of the arrow B, and the feeder side is the excavator 6, the outer shell jack 2D, and the like.
It is connected to the elector 17 and the like.

Since the tunnel 25 during excavation has the above-described structure, when constructing the tunnel 25, the tunnel excavation device 1 is used to crush the bedrock of the face 20a so that its cross-sectional shape is horseshoe-shaped. By forming the tunnel excavation space 250 in the shape, the excavation is performed in the arrow A direction. To form the tunnel excavation space 250, first, the receiving sheet pile 5 is projected in the direction of the arrow A to support the rock in the face 20a so that the rock cannot fall. Then, the outer shell 2 is pressed through the outer shell leg 3 to drive the hydraulic jack 31 under pressure to obtain a reaction force to the invert 25b.
Push up in the direction. Then, the outer shell 2 has the primary backing material 26.
The ground 20 is supported by being pressed against the arch 25a through the. At the same time, the uncovered ground 2 between the tunnel 25 and the face 20a, which have already been lined.
In the case of 0, the primary backing material 26 prevents the skin from falling off, so that the ground 20 is stably secured. In this way, when the natural ground 20 is supported by the outer shell 2, the canopy jack 12 is pressure-loaded to push the ram 12c upward, that is, in the direction of arrow C, so that the canopy 12b is attached to the canopy portion of the front body 2A.
By pushing the side jacks 15 and 15 under pressure and pushing the rams 15c and 15c laterally, that is, in the directions of arrows E and F, the body 6a is integrated with the front body 2A. In a supported state, the cutter head 9 is rotationally driven while being swung in the directions of arrows C, D, E, and F, so that the ground 20 is cut open via the cutting blade 9a.
The cutting blade 9a is advanced in the arrow A direction by the excavation stroke L1 of the excavator 6. Then, the tunnel excavation space 250 is formed such that the cutting face 20a advances in the direction of arrow A by the excavation stroke L1. Simultaneously with or before the excavation of the cutting face 20a, particles are blown into the temporary void 21 'by appropriately pressing the primary backing material 26 made of foamed steel beads or the like from the arch 25a portion via the pressure feed pipe 27. Fill in shape. Then, the primary backing material 26 blown and filled with such a low pressure as described above becomes the outer shell 2
Without crushing inward, while allowing the deformation of the natural ground 20 to some extent, while preventing the skin from falling off from the overexposed portion,
It can serve to disperse and support the stress acting outward from the outer shell 2 along the outer peripheral surface through the primary backing material 26 to the natural ground 20. In addition, when the natural ground 20 is a poor natural ground such as spring water, extrudability, crushable rock, etc., the natural ground 20 tries to collapse in a form pushing out from the arch 25a portion toward the inside of the excavation cross section. To do. Therefore, when the outer shell leg 3 has its legs extended by further pressurizing the hydraulic jack 31, the outer shell 2 will move to the arch 25a.
Is pushed further toward. Then, the rigidity of the primary backing material 26 that is additionally compressed by being sandwiched between the outer shell 2 and the ground 20 and pressed is increased, and the drag force against the extrusion of the ground 20 can be additionally exerted. As a result, it is possible to prevent the excavated section from being crushed inward.

If the cutter head 9 advances in the direction of arrow A by the excavation stroke L1 of the excavator 6 and the cutting face 20a advances in the excavation direction by L1, the excavation is performed via the slide shoe mechanism 7 here. Move machine 6 forward. At this time, first, the pressure of the hydraulic jack 31 is released to contract the outer shell leg 3. Then, the outer shell leg 3 is lifted from the invert 25b, and the front torso 2A is mounted on the canopy 12b, 12b with the canopy 12b.
It is in a state of being supported by a. In this way, when the side jacks 15 and 15 are pressure-released, and the canopy jacks 12 and 12 are pressure-released, the canopy 12
The front body 2A descends in the downward direction, that is, in the direction of arrow D, together with b and 12b such that the canopy portion of the front body 2A is separated from the primary backing material 26. In this way, when the front body 2A is mounted and supported on the machine body 6a, the slide shoe mechanism 7 is appropriately driven,
The machine body 6a is advanced in the direction of arrow A by the movement stroke L2. Then, since the slide shoes 7A and 7B are formed in the shape of a ski and the ground 20 is rocky, the body 6a with the front body 2A mounted and supported exerts a reaction force on the invert 25b. It is possible to easily advance in the direction of excavation together with the front body 2A in a desired form. In addition, the temporary void 2
The primary backing material 26 filled in 1'is a non-consolidating particulate material such as sand or styrofoam beads, and the primary backing material 26 of the arch 25a portion is a canopy 12b, 12c.
Since the front body 2A has already been cut off and separated from the canopy portion of the front body 2A with the descent of b,
It is possible to easily slip through the temporary void 21 'without hindering the advance of "a". In this way, the front body 2A is moved to the excavator 6a.
After moving forward by the movement stroke L2 while being supported by
When excavating the face 20a again, first, the canopy jacks 12, 12 are driven to push the front body 2A upward, and then the hydraulic jack 31 is pressed to push the outer shell leg 3 downward. The shell 2 is in a state of supporting the natural ground 20. After that, the canopy jacks 12 and 12 and the side jacks 15 and 15 are driven to be pressed again, so that the excavator 6a is supported by the front body 2A, and the drive of the cutter head 9 is restarted. By doing so, the face 20a is excavated. On the other hand, when the front torso 2A and the fuselage 6a move forward, the rear torso 2B is left behind without advancing, and the relay torso 2C exits from the rear end of the front torso 2A in a state of retreating from the front torso 2A. ing. Therefore, the rear body 2B is moved to the rear body 2B when the face 2a is moved forward and the ground 20 in the newly opened portion is appropriately stabilized.
The outer shell leg 3 is contracted, the rear body 2B and the primary backing material 26 are trimmed, and in this state, the outer shell jack 2D is driven to draw the outer shell jack 2D to the front body 2A by a drive stroke L3. The rear body 2B is moved in the direction of arrow A in the shape.

Thus, when the rear body 2B is advanced in the excavation direction by the drive stroke L3 of the outer shell jack 2D, the segment 16 which is located at the most distal end of the lining-installed segment 16, that is, the segment 16 located at the end of the arrow A direction. At the rear part of the rear body 2B, that is, at the end portion in the direction of the arrow B, there is a gap corresponding to the forward movement L3 of the rear body 2B. Therefore, the oblong annular segment 16 is mounted on the segment carrier 30 as shown in FIG. In shape, bring it into the rear body 2B. Then, by arranging the segment 16 in the horizontally elongated state on the side of the erector 17 and driving the boom jack 191, as shown in FIG. It is vertically oriented and inverted by 90 ° so that the axial center CT of the segment 16 coincides with the directions of arrows A and B, which are the tunnel building directions. Then, by pushing out the boom 19 in the direction of the arrow B, the segment 1 which is vertically elongated is raised.
6 is disposed in the rear portion of the rear body 2B, that is, in the vicinity of the end portion in the direction of the arrow B, so as to be connected to the already-installed segment 16 via a fastening bolt or the like. At this time, since the segment 16 is already formed in an oval shape, it is not necessary to assemble the segment pieces divided in the tunnel circumferential direction in an annular shape, and the segment 16 to be newly installed and already installed. Of the segment 16 of the segment support means 29
The joining operation can be easily carried out only by aligning the end faces of the segments 16 and 16 by centering through the.

By the way, a large-diameter duct 32 and a small-diameter duct 33, which are extended from appropriate equipment installed on the side of the tunnel 25 in the direction of the arrow B, have already been formed at the outside 22b of the mortar structure of the backfill layer 21. The large-diameter duct 32 and the small-diameter duct 33 are laid, and the leading end portions of the large-diameter duct 32 and the small-diameter duct 33 are open in the outer shell 2. Then, as the outer shell 2 is advanced in the direction of excavation, that is, the direction of the arrow A, as the segments 16 are sequentially built up as described above, a new backing layer 21 is formed between the outer shell 2 and the segment 16. The temporary voids 21 ′ are formed so as to be continuously extended in the arrow A direction. Therefore, in order to extend and lay the large-diameter duct 32 and the small-diameter duct 33 outside the mortar structure portion 22b at the same time as or before building the segment 16, first, the outer shell leg 3 is driven to drive the hydraulic jack 31. When the legs are extended by, the cross-sectional shape of the tunnel excavation space 250 becomes stable with the ground 20 supported by the outer shell 2. In this way, the large-diameter duct 32 and the small-diameter duct 33 having the lengths adapted to the excavation stroke L1 and the driving stroke L3 of the outer shell jack 2D are already installed via the joint pipe. Install the extension by connecting it to. The drive cable housed in any of the small-diameter ducts 33 is also extended in the direction of arrow A by means of pulling or connecting, as in the large-diameter duct 32 and the small-diameter duct 33. Then, the backfill layer 21 is filled with the mortar 22 at a high pressure via the grout pump 23 to carry out secondary backfill. Then, the natural ground 20 at the portion where the large-diameter duct 32 and the small-diameter duct 33 are extended and laid,
Since the tunnel excavation space 251 has a stable cross-sectional shape which is at or adjacent to the ground 20 of the portion supported by the outer shell 2, the mortar 22 is uniformly and densely provided in the backfill layer 21. Can be filled. Then, the mortar 22 fills the voids between the respective particles of the primary backfill material 26, such as the styrene foam, which have already been filled in the temporary voids 21 ′, and further penetrates into the surface of the natural ground 20, The backing layer 21 is filled. In this way, the segments 16 are sequentially built in the tunnel excavation space 251, and the segments 16 are fixed to the natural ground 20 via the mortar 22 filled in the backfill layer 21, whereby the tunnel structure 251 is constructed. To go. By the way, the main structural member in the tunnel structure 251 is the segment 16 which is the lining member, and the mortar structure portion 2
2a is configured to reinforce the outer circumference of the segment 16 so as to surround it with a winding thickness W1. However, among the mortar 22 filled in the backfill layer 21, the corner portions formed by the side walls 25c and the inverts 25b, that is, the outside 22b of the mortar structure portion arranged on the lower left and right in FIG. It is excluded by design and is not considered as a structural member of the tunnel structure 250. Therefore, the mortar 22 outside the mortar structure portion 22b functions only as a backing material for filling the voids, and by disposing the large-diameter duct 32 and the small-diameter duct 33 as described above, Even if the outside 22b of the structure portion has a cross-section loss, the tunnel structure 2
Not only is 50 not affected, but the outside 22b of the mortar structure can be effectively utilized. Further, since the mortar 22 outside the mortar structure portion 22b is individually connected, the load carrying capacity outside the mortar structure portion is increased. Therefore, even if a large-diameter duct 32 and a small-diameter duct 33 are laid, inexpensive thin PVC pipes are laid. There is no concern that the large-diameter duct 32 and the small-diameter duct 33 will be destroyed by being applied with an excessive load. Similarly, the large diameter duct 32 and the small diameter duct 33 are
Even if it is a C concrete pipe, there is no fear of cracking. In this way, the large-diameter duct 32 and the small-diameter duct 33 laid on the outside 22b of the mortar structure are extended in the direction of the arrow A to be appropriately opened in the outer shell 2, and the drive cable selectively accommodated in the small-diameter duct 33. Is extended and appropriately connected to the outer shell jack 2D, the excavator 6, the erector 17, and the like. Then, since the water supply / drainage, air supply / exhaust, and power supply required for the tunnel excavation device 1 can be performed at all through the large-diameter duct 32 and the small-diameter duct 33, a work duct, a drive cable, or the like is provided in the segment 16. There is no need to lay it separately. Therefore, a sufficient working space is left in the segment 16 even if the space for the transport carriage 30 for transporting the segment 16 can be secured. Further, large-diameter ducts 32, 32 laid on one side of the outside 25b of the mortar structure portion shown on the left side in FIG.
After the tunnel structure 251 is constructed, that is, after the excavation work is finished, the tunnel structure 251 and the inside of the segment 16 are selectively and appropriately connected. And the duct 3 communicating with the natural ground 20
The reference numeral 2 is used as a water drain hole of the natural ground 20, and the duct 32 communicating with the inside of the segment 16 is used as an in-counter drainage duct. By doing so, not only is the large-diameter duct 32, 32 used as a temporary duct for work during excavation,
Since it can be permanently used as a part of the tunnel structure 251, the outside 22b of the mortar structure can be used more effectively.

Thus, the cutting face 20 is cut by the cutter head 9.
While excavating and advancing a, the front body 2A and the rear body 2B are sequentially advanced, and at the same time, the injection and filling work of the primary backing material 26 and the mortar 22 and the building work of the segment 16 are sequentially repeated under appropriate steps. As a result, it is possible to complete the construction of the lining at the same time as the excavation work in the outer shell 2 without the need to separately assemble a steel support and a formwork for concrete in the tunnel 25. Therefore, it goes without saying that the construction time required for constructing the tunnel 25 is short, and the excavation work is performed under the condition that the outer shell 2 always secures the stability of the ground 20 of the face 20a, and Since the primary backfilling work is performed at the same time as the excavation, the internal stress of the ground 20 to be cut open is less likely to be disturbed. For this reason, the tunnel 25 constructed as described above can ensure the safety during construction and can exhibit a stable structural state even after the construction.

[0016]

As described above, according to the present invention,
A tunnel excavation space 250 is formed by excavating the natural ground 20 through excavation work means such as the tunnel excavation device 1 arranged at the tip portion in the excavation direction, and the tunnel excavation space 250 is cut into the tunnel excavation space 250. When constructing the tunnel structure 251 formed by building the segment 16 having a small cross-sectional area with respect to the area in a form following the excavation work means, the tunnel excavation space 25
0, a duct accommodating portion such as the mortar structure outside 22b is provided so as to be arranged between the tunnel structure 251 and the natural ground 20, and the duct accommodating portion includes a power and fluid duct 32, Since the supply and recovery paths such as 33 are arranged so as to connect the excavation work means and the rear side of the tunnel structure 251, the power and the fluid are supplied through the supply and recovery paths. Can be transported. Therefore, it is not necessary to lay in the segment 16 temporary wires and ducts for supplying and recovering the power required for the excavation work means, air, water, etc., so that the space in the segment 16 is used as a work area. It can be used effectively. Therefore, in a mountain tunnel, the segment 16 integrally formed in an oval shape in the circumferential direction is laid down in an oblong shape and transported in a manner to pass through the segment 16 already built, and the work of building is easily performed. As a result, the working environment is improved, the construction efficiency is improved, and as a result, a good-quality tunnel 25 is constructed. Further, according to the present invention, by effectively utilizing the portion of the backfill layer 21 that does not function as a structural member of the tunnel structure 251 as the duct accommodating portion, it is possible to eliminate a wasteful portion in the tunnel 25. I can. Therefore, according to the present invention, since the tunnel 25 having a small cross section and a high space efficiency can be constructed, the tunnel excavation space 2 such as a water channel or a pipeline can be constructed.
It is also suitable for application in tunnels 25 where 50 spaces are limited.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an example of a tunnel excavation device used in the present invention.

FIG. 2 is a construction side view showing an example of tunnel excavation work.

FIG. 3 is a construction top view showing an example of a tunnel excavation work.

FIG. 4 is a cross-sectional view showing an example of a tunnel constructed according to the present invention.

[Explanation of symbols]

 1 …… Tunnel excavation device (excavation work means) 16 …… Segment 20 …… Ground 22b …… Outside mortar structure part (duct accommodating part) 32, 33 …… Duct (feed and recovery route) 250 …… Tunnel excavation space 251 ... Tunnel structure

Claims (1)

[Claims] 1. A tunnel excavation space is formed by excavating a natural ground through excavation work means arranged at a tip end portion in the excavation direction, and the tunnel excavation space has a small size with respect to a cross-sectional area of the tunnel excavation space. When constructing a tunnel structure formed by building a segment having a cross-sectional area in a form following the excavation work means, a duct accommodating portion is provided in the tunnel excavation space, the tunnel structure and the ground. It is provided so as to be arranged between the mountain and the duct accommodating portion, and a power and fluid supply / recovery path is provided.
A tunnel construction method, wherein the excavation work means and the rear side of the tunnel structure are arranged so as to be connected to each other.