JPH07127374A - Method for constructing tunnel - Google Patents

Abstract

PURPOSE:To certainly execute works for reinforcement and water stopping without difficulties even when bedrock to which a tunnel is constructed is weak, and to easily execute work for lining for the inner wall of the tunnel with reinforced concrete. CONSTITUTION:In excavating a tunnel with its cross section divided into four parts of upper right, upper left, lower right and lower left, excavation is executed, from a first quarter 1 on one side on the upper part, and is advanced to a second quarter 7 right below the first quarter, to a third quarter 12 on the other side on the upper part, and to a fourth quarter 15 right below the third quarter. The excavation is executed with a middle wall 4 left behind for partitioning the cross section of the tunnel into the right and the left parts and after the middle wall 4 is removed, work for an invert 10 serving as a floor slab is executed. Then, work for lining is executed on the inner wall, extending upward from the invert 10, and thereby closure is made early for each of the parts of the cross section of heading, and reinforcement against the earth pressure acting on the tunnel from above is made by the middle wall 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel construction method for constructing a large-section tunnel on soft ground such as a hydrous unconsolidated gravel layer.

[0002]

2. Description of the Related Art As a method for constructing a tunnel, a shield construction method of excavating with a shield excavator and a construction method of directly excavating the natural ground with an ordinary excavator or blasting are known. The shield method is suitable for excavation on soft ground and urban areas, and is a method that has been widely adopted in recent years, but the shield excavator uses a steel cylindrical frame called a skin plate with a diameter of, for example, 10 m. Since it is technically difficult to make it larger than that and it is difficult to install it, it shields wide roads with multiple lanes and large cross-section tunnels that can pass through these roads and railways together. It cannot be excavated by the construction method, and in the past, the construction method by the direct excavation was used.

[0003]

However, in the method of direct digging, in the case where the ground to be tunneled is a soft ground such as a hydrous unconsolidated gravel layer, in order to construct a tunnel having a large cross section, There is a problem in that construction is difficult because it is necessary to consider static pressure as well as soil pressure when the water level is above the tunnel.

Further, when lining the inner wall of the tunnel, considering the earth pressure and the hydrostatic pressure, it is suitable to perform the lining with reinforced concrete, but in this case, since the tunnel has a large cross section, When transporting and assembling on the inner wall side of the tunnel, the number of rebars to be transported increases and the diameter of the rebars also increases, so that manual work or transportation by a simple crane, etc., imposes a heavy burden on workers and cranes. There is a problem that the transfer work becomes difficult and complicated, and not only the lining with reinforced concrete becomes difficult, but also the construction period becomes long.

The present invention has been made in view of the above circumstances, and can easily and surely stop water and reinforce even when the ground to be tunneled is a soft ground such as an unconsolidated gravel layer containing water. It is an object of the present invention to provide a tunnel construction method capable of performing the lining and easily lining the inner wall of the tunnel with reinforced concrete.

[0006]

In order to achieve the above object, the tunnel construction method according to claim 1 of the present invention is as follows.
After excavating one of the upper quadrants of the tunnel cross section, excavate the lower quadrant immediately below it, then excavate the other quadrant above, and then the lower quadrant immediately below At this time, excavation is performed by leaving an inner wall that divides the tunnel cross-section space into left and right, then, after removing this inner wall, an invert part that will be a floor slab is constructed, and then the tunnel inner wall above the invert part is covered. It is characterized by working.

The tunnel construction method of claim 2 is the method of claim 1.
In the above, the lining of the invert part and the inner wall of the tunnel is constructed by reinforced concrete.

The tunnel construction method of claim 3 is the method of claim 1
Or 2, in lining the inner wall of the tunnel, after constructing a sheet for water stop along the inner wall of the tunnel, constructing a support work for assembling the reinforcing bar from the floor slab along the inner wall of the tunnel, and thereafter, The feature of this method is to attach concrete to the support work and to attach concrete to the support, and to place concrete.

The tunnel construction method of claim 4 is the method of claim 3
At the time of transporting the grid-shaped reinforcing bars to a predetermined position of the support work, inside the inner wall of the tunnel, guide rails are arranged in the circumferential direction along the inner wall of the tunnel.
It is characterized in that a carrier truck is provided movably along the inner wall of the tunnel, and the carrier truck transports the lattice-shaped reinforcing bars to a predetermined position of the support work.

[0010]

According to the tunnel construction method of claim 1 of the present invention, when excavating the tunnel section by dividing the section into four parts vertically and horizontally, the four halves on the upper side of the tunnel cross section and the four quadrants on the lower side immediately below the tunnel section. Half, the other quadrant on the upper side, and the lower quadrant immediately below it are excavated sequentially, at that time, excavating leaving an inner wall that divides the tunnel cross-sectional space into left and right, and then removing this inner wall Later, by constructing the invert part that will be the floor slab, and then lining the tunnel inner wall above the invert part, early closing of each back and back is performed, and reinforcement against earth pressure acting from above the tunnel is also performed. Is performed by the inner wall.

According to the tunnel construction method of claim 2,
The reinforcement of the tunnel with a large cross section will be made stronger by constructing the invert part and the lining of the tunnel inner wall with reinforced concrete.

According to the tunnel construction method of claim 3,
After constructing a sheet for waterproofing along the inner wall of the tunnel, a supporting work for assembling the reinforcing bars was constructed from the invert part along the inner wall of the tunnel, and then the supporting structure was assembled with reinforcing bars in a grid pattern. The inner wall of the tunnel will be lined with reinforced concrete, which will ensure the waterproofing of the tunnel by assembling the reinforcing bars and placing concrete.

According to the tunnel construction method of claim 4,
Inside the inner wall of the tunnel, guide rails are arranged in the circumferential direction along the inner wall of the tunnel, and on this guide rail, a carriage is provided so as to be movable along the inner wall of the tunnel. By transporting to a predetermined position for supporting work, even in a tunnel with a large cross section, the reinforcing bars to be mounted on the inner wall surface can be transported easily, quickly and safely.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the tunnel construction method of the present invention will be described below with reference to the drawings. 1 to 7 are diagrams showing an embodiment of a tunnel construction method of the present invention in the order of steps. In the present invention, the cross section of the tunnel is divided into four parts to be excavated. First, if the current water level is located above the tunnel, a few meters below the tunnel to be excavated as a pre-stage step of this excavation. In addition, the drainage shield and the drainage boring are used to lower the water level, and the ground is improved by injecting a chemical solution into the ground if necessary.

After that, as shown in FIG. 1, the upper one (left side) quadrant 1 of the tunnel cross section is excavated by a predetermined length in the longitudinal direction of the tunnel. This excavation is carried out by a breaker which is an excavator in which a striking force is applied by using compressed air only when attached to the tip, and the shear generated by the excavation is scooped by a side dump shovel and carried out by a dump truck. Next, the concrete 2 is sprayed on the inner wall surface of the excavation, and then the inner wall surface of the excavation is reinforced by the lock bolts 3 ... The lock bolts 3 are formed by drilling the inner wall surface of the excavation using a crawler jumbo, inserting the lock bolts into the holes, and tightening the nuts. Also, when excavating the upper quadrant 1 of the tunnel cross section, the inner wall 4 described later is used.
Excavation is performed while leaving half the thickness of the upper portion 4a of the above, and concrete 5 is also sprayed on the portion of the inner wall 4 which becomes the upper portion 4a and further reinforced by the lock bolts 6 ...

Next, as shown in FIG. 2, the quadrant 7 immediately below the digged quadrant 1 is excavated for a predetermined length in the longitudinal direction of the tunnel, and concrete 8 is sprayed on the excavated inner wall surface. The inner wall surface of the excavation is reinforced with lock bolts 9 ... In this case, drilling, concrete spraying,
The lock bolt 9 is inserted in the same manner as described above, but the concrete 8 is also sprayed onto the portion where the invert portion 10 described later is constructed. When excavating the lower quadrant 7 of the tunnel cross section, the inner wall 4 to be described later is also used.
Excavation is performed with half the thickness of the lower portion 4b of the inner wall 4 left, and the concrete 11 is also sprayed on the lower portion 4b of the inner wall 4.

Next, as shown in FIG. 3, the other (right) quadrant 12 on the upper side of the tunnel section is excavated by a predetermined length in the longitudinal direction of the tunnel in the same manner as described above, and concrete is excavated on the excavated inner wall surface. 13 is sprayed, and the inner wall surface of the excavation is further reinforced by lock bolts 14 ... In the case of this excavation, the upper part 4 of the middle wall 4 that divides the tunnel cross-section space into left and right
The upper part 4a of the inner wall 4 is formed in the upper half of the tunnel cross section by excavating while leaving half the thickness of the portion a.

Next, as shown in FIG. 4, the quadrant 15 immediately below the digged quadrant 12 is excavated for a predetermined length in the longitudinal direction of the tunnel, and concrete 16 is excavated on the excavated inner wall surface.
And the inner wall surface of the excavation to the rock bolt 1
7 ... so reinforce. In this case, the concrete is sprayed also on the portion where the invert portion 10 described later is constructed. Further, in the case of this excavation, the lower portion 4b of the inner wall 4 is formed in the lower half of the tunnel section by excavating while leaving half the thickness of the portion that becomes the lower portion 4b of the inner wall 4 that divides the tunnel sectional space into left and right. The upper and lower portions 4a of the inner wall 4 that are formed are vertically connected to each other to form the inner wall 4 that divides the tunnel cross-sectional space into left and right as shown in FIG.

When the excavation is performed as described above, the earth wall can be reinforced against the earth pressure acting from above the tunnel, and the stability of the face, the loosening of the ground and the subsidence of the ground can be prevented. .

When the excavation of the tunnel is completed for a predetermined length, the inner wall is removed as shown in FIG. 6, and the invert portion 10 is constructed and the tunnel inner wall (side wall and arch portion) is constructed as follows. Perform lining. As shown in FIG. 7, the entire inner wall of the excavated tunnel (including the invert part 10)
After applying the sheet 18 for stopping water, first, the invert portion 10 is applied as follows. That is, after spraying the protective mortar 20 on the water blocking sheet 18 constructed in the invert part 10, a plurality of grid-like reinforcing bars 21 in which reinforcing bars are assembled in a grid shape are arranged in the circumferential direction of the inverting part 10. In this case, the grid-shaped reinforcing bars 2 adjacent to each other in the circumferential direction
1) The two are overlapped with each other to some extent to make the joining more reliable. Further, the grid-shaped reinforcing bars 21 are arranged vertically with a predetermined space therebetween, and a plurality of stopper bars 22 are arranged between these grid-like reinforcing bars.

As shown in FIG. 8, the stopper bar 22 includes a large number of mountain-shaped vertical rebars 23 ... Arranged in parallel at a predetermined interval, and a large number of linear horizontal bars 24 ... Is fixed by welding to form a reinforcing bar support 25, and a wire mesh 26 having a small opening degree capable of preventing the outflow of concrete is fixed to the entire surface of one side of the reinforcing bar support 25 except the top. A stopper bar 22 having a structure is arranged on the protective mortar 20 and the grid-shaped reinforcing bar is
By arranging, it is possible to prevent the concrete from flowing out in the circumferential direction when the concrete is placed in the invert portion 10. Further, since the vertical reinforcing bars 23 ... Have a mountain shape, the stopper bars 22 can be installed by simply placing them on the protective mortar 20. Further, the vertical reinforcing bars 23 and the horizontal reinforcing bars 24 are welded together. Therefore, it is possible to form a strong concrete weir having sufficient strength.

After the reinforcement of the invert portion 10 is completed as described above, concrete is poured into the invert portion 10. In this case, the invert part 10 has a convex curved surface formed downward, and the cast concrete tends to flow toward the bottom of the invert part 10, but the stopper bars 22 ... Are arranged in the invert part 10. Therefore, this flow can be prevented by the stopper ribs 22 ..., and the invert portion 10 having a uniform thickness can be easily and surely constructed. When placing concrete on the invert part 10, the support pieces 27, 27 made of H-shaped steel, which is a part of the support 28 for assembling the reinforcing bars for lining the tunnel inner wall, are placed in front of the concrete. The supporting pieces 27, 27 are fixed by arranging them at both ends of the invert portion, and by placing concrete on the invert portion.

After the construction of the invert part 10 is completed, the inner wall of the tunnel (side wall and arch part) is lined. First, the support work pieces 27, 27 fixed to both ends of the invert part 10
Next, the next support piece 27 is sequentially connected to the inner wall side of the tunnel along the circumferential direction to construct a support piece 28 having a substantially arc shape as a whole. In order to convey the supporting piece 27 in the tunnel, the supporting piece 27 is used to convey the supporting piece 27.

Then, the reinforcing bars for the lining are conveyed and assembled to the supporting work 28 as follows. That is, as a reinforcing bar to be assembled, a grid-shaped reinforcing bar 31 formed by assembling rod-shaped reinforcing bars in a grid shape is formed in advance in a factory or on site, and the grid-shaped reinforcing bar 31 is provided on the protective mortar 20 along the inner wall of the tunnel. Arranged and support 2 at a predetermined position
Assemble to 8. At that time, the grid-shaped reinforcing bars 3 adjacent to each other
1. The two are wrapped to some extent to make the joint more reliable.

The grid-shaped reinforcing bar 31 is a reinforcing bar conveying device 30.
Transport by. Here, the configuration of the reinforcing bar conveying device 30 will be described with reference to FIGS. 9 and 10. The reinforcing bar transfer device 30 includes a frame 32 provided inside the inner wall surface of the tunnel, guide rails 33 attached to the frame 32 and arranged circumferentially along the inner wall surface of the tunnel, and the guide rail 33. A transport carriage 34, which is movably provided along the inner wall surface of the tunnel and transports the lattice-shaped reinforcing bars 31 to the support 28, is mainly configured.

Four wheels 35 are attached to the lower end of the frame 32. These wheels 35 roll on a pair of rails 36, 36 so that the frame 32 extends along the longitudinal direction of the tunnel. It is provided to be movable. A moving frame 37 is arranged above the frame 32, and the moving frame 37 is provided so as to be movable left and right with respect to the frame 32 by rollers 38. On the other hand, a hydraulic cylinder 39 is installed above the frame 32.
The moving frame 37 is moved to the left and right.

On the moving frame 37, a plurality of support rods 40 ... Are erected at right and left at predetermined intervals and in parallel with each other in the longitudinal direction of the tunnel. On the other hand, above the support rods 40, a pair of guide rails 33, 33 extending in the circumferential direction along the inner wall surface of the tunnel are arranged inside the supporting work 28.
3, 33 are supported by the tip portions of the support rods 40 ... The guide rail 33 is formed in a curved shape substantially parallel to the inner wall surface of the tunnel, and is formed by, for example, connecting H-shaped steels bent in a predetermined curvature in the circumferential direction.

A transport carriage 34 is provided on the guide rail 33 so as to be movable along the guide rail 33. That is, four wheels 34 a are attached to the carrier truck 34, and the wheels 34 a are rolled on the guide rails 33, so that the carrier truck 34 is movably provided along the guide rails 33. There is. A roller chain 33a is stretched on the upper surface of the guide rail 33 along the longitudinal direction of the guide rail 33, and both end portions of the roller chain 33a are provided at both end portions of the guide rail 33, respectively. It is locked to the locking portions 33a, 33a with the take-up. On the other hand, at the center of the upper surface of the carrier truck 34, the carrier truck 3
A drive unit 45 for driving the drive unit 4 is provided. The drive unit 45 has an electric motor 45a, and the roller chain 33a is hooked on the electric motor 45a to drive the electric motor 45a.
By rotating a, the transport carriage 34 is moved along the roller chain 33a.

Further, a plurality of guide rollers 41 ... Are attached to the guide rail 33, and the guide rail 3
Bend rollers 42 are rotatably provided in the vicinity of both ends of 3, respectively. The cable reel 43 rotatably supported at the right side of the bend roller 42.
, A power feeding cable 44 is unwound and continuously wound around the bend roller 42, the guide roller 41, ..., And the tip end thereof is connected to the electric motor 45a. on the other hand,
From the hydraulic hose reel 48 rotatably supported at the left side position of the bend roller 42, the hydraulic hose 48
a is unwound, continuously hung on the bend roller 42, the guide roller 41, ... And connected to the hydraulic cylinder. Further, on the upper surface of the carrier vehicle 34, there is provided a reinforcing bar setting portion 46 for setting the grid-shaped reinforcing bars 31 so as to approach and separate from the inner wall surface side of the tunnel. The reinforcing bar setting section 46 is composed of a pair of elevating sections 47, 47. The elevating part 47 is of a so-called pantograph shape in which a plurality of link materials are crossed and rotatably connected to each other. The elevating part 47 is moved up and down by a hydraulic cylinder (not shown) connected to a lower end of the link material. The grid-shaped reinforcing bars 31 placed on 47 are set.

On the frame 32, the carriage 3
A supply device 50 for supplying the grid-shaped reinforcing bars 31 is provided at the position 4. That is, a pair of guide frames 51, 51 are erected on the frame 32 so as to be parallel to each other and substantially vertically, and the guide frames 51, 51 are mounted on the guide frames 51, 51.
2 is provided so that it can be raised and lowered. The lift truck 52 is provided with a drive unit 53 that drives the lift truck 52. The drive unit 53 has an electric motor 53a, and a chain 54 extending in the longitudinal direction (vertical direction) of the guide frame 51 and fixed at both ends is hooked on the electric motor 53a. By rotating 53a, the lift truck 52 is moved up and down along the chain 54.

A support base 55 is fixed to the lift carriage 52, and two sets of supply portions 56 for supplying the grid-shaped reinforcing bars 31 to the carrier carriage 34 are provided on the support base 55 vertically separated from each other. ing. As shown in FIG. 10, each supply unit 56 includes a fixed frame 57 and a movable frame 5 provided on the fixed frame 57 so as to be movable in the longitudinal direction of the tunnel.
8 and the main components. The fixed frame 5
7, a drive unit 60 having the same configuration as the drive unit 45 is provided, while a moving frame 58 is provided with a chain (not shown). The moving frame 58 is moved in the longitudinal direction of the tunnel by rotating an electric motor (not shown) of the driving unit 60. Further, as shown in FIG. 9, a hydraulic cylinder 61 is provided on the support base 55, and the hydraulic cylinder 61 adjusts the inclination angle of the fixed frame 57 with respect to the horizontal plane.

In the supply device 50 having the above-mentioned structure, after the grid-shaped reinforcing bars 31 are placed on the moving frame 58, the lifting carriage 57 is lifted to the vicinity of the origin position of the carriage 34.
Next, by moving the moving frame 58 forward, the grid-shaped reinforcing bars 31 are supplied to the upper position of the carrier truck 34. The supplied grid-shaped reinforcing bars 31 raise the elevating part 47 of the carrier carriage 34 to raise the carrier carriage 34. To be received by. Further, in the frame 32, four hydraulic cylinders 62 ... Inside the guide rail 33.
Is attached, and by extending the support support 63 fixed to the piston rod of each hydraulic cylinder 62 to the outside of the guide rail 33, the grid-shaped reinforcing bar 3
The support work 28 for assembling 1 is supported in the tunnel to prevent it from collapsing.

In order to convey the lattice-shaped reinforcing bar 31 to a predetermined assembly position by using the reinforcing bar conveying device 30 having the above structure,
First, after the grid-shaped reinforcing bars 31 are placed on the moving frame 58 of the supply device 50, the lifting carriage 52 is raised to the vicinity of the origin position of the transport carriage 34, and then the moving frame 58.
The grid-shaped reinforcing bars 31 are moved by moving the carriage 3 forward.
4 to the upper position. Next, the grid-shaped reinforcing bars 31 are moved from the moving frame 58 to the elevating part 47 by elevating the elevating part 47 of the reinforcing bar setting part 46 of the carriage 34.
Hand over to. When the lattice-shaped reinforcing bars 31 are delivered, the inclination angle of the fixed frame 57 is adjusted to adjust the inclination of the lattice-shaped reinforcing bars 31 to reliably deliver the lattice-shaped reinforcing bars 31.

After that, by driving the drive unit 45 of the transport carriage 34 (rotatably driving the electric motor 45a), the transport carriage 34 is moved along the guide rail 33 and stopped at a predetermined position. In this case, the cable 44 is arranged along the guide rail 33, and the electric carriage 45 a is moved by engaging the electric motor 45 a with the cable 44. It can be moved smoothly.

Next, by further raising the elevating part 47, the lattice-shaped reinforcing bar 31 is brought close to the supporting work 28 for assembling the reinforcing bar and is attached to the supporting work 28. And
By repeating the supply of the grid-shaped reinforcing bars 31 by the supply device 50, the movement of the grid-shaped reinforcing bars 31 by the carriage 34, and the assembling to the support 28 in sequence, the grid is formed along the circumferential direction on the inner wall surface side of the tunnel. Assemble the reinforcing bar 31. When the assembly of the grid-shaped reinforcing bars 31 is completed, the reinforcing bar conveying device 30
Is moved in the longitudinal direction of the tunnel, and the assembling of the grid-shaped reinforcing bar 31 at the next position is performed through the same steps as described above.
By repeating this, the lattice-shaped reinforcing bars 31 are assembled one after another on the inner wall surface of the tunnel.

Incidentally, the support work 28 for assembling the grid-shaped reinforcing bars 31 uses the feeding device 50 of the reinforcing-bar transferring apparatus 30 and the carrier truck 34 to carry it to the tunnel inner wall surface side in the same manner as the grid-shaped reinforcing bars 31. The supporting work support 63 is extended to the inner wall surface side of the tunnel by the hydraulic cylinder 62, and is supported by the supporting work support 63.

After the assembling of the grid-shaped reinforcing bars 31 is completed as described above, a formwork (not shown) is arranged inside the grid-shaped reinforcing bars 31 and concrete is placed therein to complete the lining of the tunnel inner wall. .

[0038]

As described above, according to the first aspect of the present invention.
According to the tunnel construction method of, when excavating the tunnel cross section into four parts in the vertical and horizontal directions, one of the upper four quarters of the tunnel cross section, the lower four quarters directly below the tunnel cross section, and the other upper four quarters, The lower quadrant immediately below is excavated one by one, and at that time, the inner wall that divides the tunnel cross-section space into left and right is left, and then the inner wall is removed, and then the invert part that will be the floor slab is constructed. After that, since the inner wall of the tunnel above the invert part was lined, early closing for each back can be done, and reinforcement against earth pressure acting from above the tunnel can be performed by the inner wall, It is possible to prevent face stability, loose ground and subsidence. Therefore, even if the ground for which the tunnel is to be constructed is soft ground such as a hydrous unconsolidated gravel layer, the construction of a tunnel having a large cross section can be performed easily and reliably.

According to the tunnel construction method of the second aspect, since the lining of the invert portion and the inner wall of the tunnel is constructed of reinforced concrete, the reinforcement of the tunnel having a large cross section can be made stronger.

According to the tunnel construction method of claim 3, after the sheet for waterproofing is constructed along the inner wall of the tunnel, the support for assembling the reinforcing bar is constructed from the invert portion along the inner wall of the tunnel, and thereafter, Since the grid-shaped reinforcing bars in which the reinforcing bars are assembled in a grid shape were attached to the support work and concrete was placed, the lining of the tunnel inner wall with reinforced concrete that ensured the waterproofing of the tunnel was easily performed. You can

According to the tunnel construction method of the fourth aspect, the guide rails are disposed inside the inner wall of the tunnel in the circumferential direction along the inner wall of the tunnel, and the carrier is provided along the inner wall of the tunnel along the inner wall of the tunnel. Since it is provided so as to be movable and the grid-shaped reinforcing bars can be transferred to the predetermined position of the support work by this transfer cart, it is possible to easily, quickly and safely transfer the reinforcing bars to be mounted on the inner wall surface even in a large section tunnel. Not only can it be done, but the construction period can be shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of a tunnel construction method of the present invention, showing a state in which an upper left quadrant of a tunnel is excavated.

FIG. 2 is a sectional view showing a state where the lower left quadrant of the tunnel is excavated.

FIG. 3 is a sectional view showing a state in which the upper right quadrant of the tunnel has been excavated.

FIG. 4 is a sectional view showing a state in which the lower right quadrant of the tunnel is excavated.

FIG. 5 is a sectional view showing a state in which an inner wall is left.

FIG. 6 is a sectional view showing a state in which the excavation of the tunnel is completed.

FIG. 7 is a cross-sectional view showing a state where grid-like reinforcing bars for lining are arranged on the inner wall of the tunnel.

FIG. 8 is a perspective view showing a stopper streak arranged in the invert portion.

FIG. 9 is a front view showing a reinforcing bar conveying device.

FIG. 10 is a side view of the same.

[Explanation of symbols]

 1 Upper quadrant of the tunnel cross section 4 Middle wall 7 Lower quadrant of the tunnel cross section 10 Inverted part 12 Other quadrant of the upper side of the tunnel cross section 15 Other quadrant of the lower side of the tunnel cross section 18 Stop Water sheet 21, 31 Lattice reinforcing bar 22 Stopper bar 28 Supporting work 30 Rebar carrier device 33 Guide rail 34 Carriage cart

Front page continuation (72) Inventor Aki Sakaki Ao Sakaki 2-10-26 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd. (72) Shuji Maekawa 2-10-26 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd. (72) Inventor Yukihisa Inagawa 144 Shijomachi, Motosu-gun, Gifu Prefecture Gifu Industry Co., Ltd. (72) Toru Yamazaki 144 Shijocho, Motomasu-cho, Gifu Prefecture Gifu Industrial Co., Ltd. In-house (72) Inventor Toshio Kai 2-1-1, East Port, Kokurakita-ku, Kitakyushu, Fukuoka Prefecture Sumitomo Steel Co., Ltd. Steel Products Co., Ltd.

Claims (4)

[Claims] 1. A tunnel construction method for constructing a large cross-section tunnel, wherein when excavating a tunnel cross section into four sections, up, down, left and right, first of all, after excavating one upper half of the tunnel section, Excavate the lower quadrant directly below,
Then, after excavating the other upper half, when excavating the lower half just below it, excavate leaving the inner wall that divides the tunnel cross-section space into left and right, and then removing this inner wall After that, construct the invert part that will be the floor slab, and then
A tunnel construction method characterized by lining the tunnel inner wall above the invert portion. 2. The tunnel construction method according to claim 1, wherein the lining of the invert portion and the tunnel inner wall is constructed of reinforced concrete. 3. The tunnel construction method according to claim 1 or 2, wherein when lining the tunnel inner wall, a sheet for waterproofing is constructed along the inner wall of the tunnel, and then a support work for assembling the reinforcing bar is applied to the inner wall of the tunnel. After that, build a grid-like rebar, which is made by assembling rebars in a grid pattern, into the support work.
A tunnel construction method characterized by placing concrete. 4. The method for constructing a tunnel according to claim 3, wherein when the lattice-shaped reinforcing bars are transported to a predetermined position for supporting work,
Inside the inner wall of the tunnel, guide rails are arranged in the circumferential direction along the inner wall of the tunnel, and on this guide rail, a carriage is provided so as to be movable along the inner wall of the tunnel. A tunnel construction method characterized by transporting to a predetermined position of support work.