JP2000073686A - Construction method of large section tunnel - Google Patents

Abstract

(57) [Abstract] [Problem] To provide a construction method of a large-section tunnel which enables economical construction, labor-saving construction, and cost reduction. A plurality of single tunnels are excavated while lining with a plurality of steel segments. Next, a plurality of single tunnels are connected to one space, and concrete 5 is cast therein, thereby constructing an outer frame 6 having a large cross section. Next, a large-section tunnel A is constructed by excavating earth and sand in the outer frame 6. At this time, the single tunnels a adjacent in the circumferential direction of the large-section tunnel A are joined to each other by the plurality of joining members 10. Further, a plurality of reinforcing steel bars 4 are arranged continuously in the circumferential direction of the large-section tunnel A in the concrete 5 of the plurality of single tunnels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a large-section tunnel for forming a rectangular or circular large-section tunnel.

[0002]

2. Description of the Related Art Heretofore, as shown in FIG. 18, for example, as shown in FIG. 18, the applicant first builds a rectangular or circular outer shell body 30 having a large cross section, and then builds this outer shell body 30. A large section tunnel construction method has been developed in which a large section tunnel A is constructed by excavating the inner soil with general-purpose heavy equipment.

[0003] At that time, the outer shell body 30 first excavates while lining a single-section shield tunnel a (hereinafter referred to as “simple tunnel”) with a plurality of steel segments 31,
Next, the single tunnels a are constructed by removing a part or all of the partition part b so as to be continuous with one space, and further placing concrete 32 in the continuous space.

[0004] The steel segment 3 used here is also used.
1, a plurality of main girders 33 extend in parallel in the circumferential direction of a single tunnel a as shown in FIG.
A plurality of vertical ribs 34 are attached at predetermined intervals in the longitudinal direction of the main girder 33 between the main frame 33 and the main frame 33 to form a lattice frame, and a skin plate 35 is attached to one side surface of the lattice frame. ing.

As an example of a method for designing the strength of the steel segment 31, there is a method in which the steel segment 31 is designed as a main body structure (body) for lining the large-section tunnel A.
As another design method, the steel segment 31 is not used as the main structure of the large-section tunnel A, and the single-piece tunnel a is not used.
There is a method of using only a structural member for lining a single tunnel a when excavating a tunnel, and arranging reinforcing reinforcing bars forming a main structure of an RC structure separately from the main structure of the large-section tunnel A.

[0006] The former is mainly composed of the main girder 3 of the steel segment 31.
Numeral 3 is regarded as a bending material (beam) that resists the sectional force of the single tunnel a (stress generated by surrounding earth pressure, water pressure, etc.). Each of them is designed to be cross-sectionally regarded as a tensile steel material that forms and resists a composite structure.

[0007]

However, in such a construction method, all the tensile force generated by the sectional force of the large-section tunnel A is dealt with only by the steel segments 31. In addition, by increasing the size of the main girder 33 and the joints between the segments, the steel frame processing becomes large, and the manufacturing cost of the steel segment 31 greatly increases, and the steel material consumption increases,
There was a problem that the weight of the steel segment 31 increased and handling became difficult.

On the other hand, in the latter, since the cross section of the main girder 33 of the steel segment 31 is designed mainly based on the cross-sectional force of the single tunnel a, the consumption of steel material can be reduced and the manufacturing cost of the steel segment 31 can be suppressed. However, since the strength of the steel segment 31 is neglected with respect to the sectional force of the large-section tunnel A, a large amount of steel segments are wasted, resulting in an increase in cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a construction method of a large-section tunnel capable of economical construction, labor-saving construction, and cost reduction.

[0010]

In order to solve the above-mentioned problems, a method of constructing a large-section tunnel according to the present invention according to the first aspect of the present invention is to excavate while covering a plurality of single shield tunnels with steel segments. After that, concrete is poured into the single-piece shield tunnel to construct a large-section outer shell, and then a large-section tunnel is constructed by excavating soil in the outer shell to construct a large-section tunnel. In the above, the steel segment is installed as a resistance member that resists the sectional force of the single-piece shield tunnel and the large-section tunnel, and a plurality of reinforcing bars are arranged in the single-piece shield tunnel as a resistance member that resists the sectional force of the large-section tunnel. To streak.

In the construction method of a large-section tunnel according to a second aspect of the present invention, the tunnel is excavated while covering with a plurality of steel segments, and then concrete is poured into the steel segments to a predetermined thickness. In the method for constructing a large-section tunnel for constructing a large-section tunnel, a steel segment is installed as a resistance member that resists the section force of the tunnel, and a plurality of reinforcing bars are provided in the concrete as a resistance member that resists the section force of the tunnel. Arrange the bars.

According to a third aspect of the present invention, in the method of constructing a large-section tunnel, the single shield tunnels are joined to each other by a plurality of joining members. In the construction method of a large-section tunnel according to claim 4, in claim 1, 2, or 3, the reinforcing steel is used as a resistance member when the steel segment is installed as a resistance member that resists the section force of the large-section tunnel. Arrange the missing parts.

According to a fifth aspect of the present invention, there is provided a method of constructing a large section tunnel, wherein
Reinforcement is continuously arranged in the circumferential direction of the tunnel. In the construction method of a large-section tunnel according to claim 6, in claim 1, 2, 3, 4, or 5, the steel segment has an uneven portion or a plurality of slip stoppers for increasing adhesion to concrete.

In the construction method of a large-section tunnel according to a seventh aspect of the present invention, according to the third, fourth, fifth or sixth aspect, both ends of the joining member are fixed to a steel segment or surrounding concrete.

In the construction method for a large-section tunnel according to claim 8, in claim 3, 4, 5, 6, or 7, the joining member is made of a reinforcing bar, a high-strength reinforcing bar, a PC steel rod, a PC steel stranded wire, or a steel material. Form.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention 1 to 3
Shows an example of a large section tunnel constructed in a rectangular section. In the figure, a plurality of steel segments 1 are double-installed on the ground surface of the large-section tunnel A while being joined to each other in the axial direction and the circumferential direction of the large-section tunnel A. A plurality of shear reinforcing steel materials 3 are installed between the steel segments 1 and 1, and a plurality of reinforcing reinforcing bars 4 are arranged. After that, concrete 5 is cast.

Thus, the steel segment 1 and the reinforcing steel 4
The ground surface of the large-section tunnel A is covered with an outer shell frame 6 of a composite structure of steel and reinforced concrete constructed to a predetermined thickness from the concrete 5 and the concrete 5.

The steel segment 1 is, for example, shown in FIGS.
As shown in (c), a plurality of main girders 7 extend in the circumferential direction of the tunnel A in parallel, and a plurality of vertical ribs 8 are provided between the adjacent main girders 7 in the axial direction of the main girder 7. A rectangular grid frame 2 is formed by attaching at intervals, and the grid frame 2
Is formed by attaching a skin plate 9 to one side.

Each of the main girder 7 and the vertical ribs 8 is formed in a strip shape with a required beam structure (height) and thickness.
Is a material that resists as a bending material (beam) against the sectional force (stress due to earth pressure or water pressure from the surroundings) of a single tunnel a (see FIG. 4) excavated to construct the outer shell body 6. Is designed as

The longitudinal rib 8 is further provided with a large cross-section tunnel A so as to have sufficient strength as a reaction force receiver for obtaining a propulsive force of a shield machine (not shown) for excavating the single tunnel a.
In order to work effectively as a shear connector for the main girder 7 when the is constructed, the main girder 7 is attached at an optimum interval.

The vertical ribs 8 are reinforced by reinforcing ribs 8a as necessary so as to have a sufficient strength as a reaction force receiver for obtaining a propulsion reaction force of the shield machine. Furthermore, the main girder 7
The main girder 7, the vertical rib 8 and the skin plate 9 are joined by welding as shown in FIG. 6 (a), but the vertical rib 8 receives the propulsion reaction force of the shield machine. It is good also as a structure which can be removed after using.

The structure in this case is, for example, as shown in FIG.
As shown in FIG.
a may be protruded, and the both ends may be detachably engaged between the guide ribs 7a.

In this way, when the concrete 5 is poured, the filling property of the concrete 5 can be enhanced, and the vertical ribs 8 can be used repeatedly without being buried in the concrete 5 to be extremely economical. Becomes

Further, by removing the vertical rib 8 as a shear connector, the steel segment 1 and the concrete
If there is a problem with the integration due to the adhesion, the uneven portion 7b is formed on the surface of the main girder 7 as necessary. The uneven portion 7b is also formed on the surface of the skin plate 9 as necessary.

By doing so, the deformation characteristics of the main girder 7 and the skin plate 9 are made as close as possible to those of the reinforcing steel bar 4, so that the proof stress can be improved. It should be noted that instead of providing the uneven portion 7b, a shear connector (slip stopper) such as a stud may be used. Alternatively, the guide rib 7a may be omitted by using the uneven portion 7b as a guide rib 7a that engages both ends of the vertical rib 8.

Further, as shown in FIG. 6 (c), even when the vertical ribs 8 are not particularly removed, an uneven portion 7b to which the concrete 5 easily adheres is formed on the entire surface of the main girder 7 and the concrete is formed. By increasing the adhesive force of 5, the deformation characteristics of the main girder 7 and the reinforcing steel bar 4 can be made as close as possible to improve the proof stress.

Instead of forming the uneven portion 7b on the entire surface of the main girder 7, a shear connector (stopper) made of a stud or the like may be provided at a predetermined interval. The steel segments 1 formed in this manner are doubly installed adjacent to each other in the circumferential direction and the axial direction of the large-section tunnel A as shown in FIGS. 2 and 3.

Particularly, between the steel segments 1 and 1 of the unit tunnel a adjacent to the large-section tunnel A in the circumferential direction, for example, as shown in FIGS.
A plurality of joining members 10 made of a high-strength rebar, a PC steel bar, a PC steel stranded wire, a steel material, or the like are bridged.

The joining member 10 takes into account the reinforcing steel bars 4 arranged between the connecting portions of the single tunnels a, and at least the sectional force (mainly the tensile force) generated between the connecting portions of the single tunnels a. The number, cross-sectional area, installation interval, and the like are designed so as to bear a cross-sectional force equal to or greater than that.

The sectional force generated at the joint between the single tunnels a may be a compressive force, a tensile force, and a shear force due to bending. In designing the joint member 10, the tensile force mainly depends on the design stress and the tensile force. Become.

Both ends of the joining member 10 are inserted into recesses 13 formed in the plurality of vertical ribs 8, respectively, and a sufficient fixing length is secured at both ends of the joining member 10. In addition,
The recess 13 may be formed from the beginning, but the vertical rib 8
Has a function of receiving a reaction force for obtaining the propulsive force of the shield machine, and therefore, it is desirable to provide it at the time of installation of the joining member 10 in order to avoid a decrease in strength due to a sectional defect.

Since the concrete 5 is cast around the joint member 10 installed in this way, the adhesive force of the concrete 5 causes the joint member between the steel segments 1, 1 adjacent in the circumferential direction of the large-section tunnel A to be joined. The transmission of stress is made via 10.

FIGS. 8 (a), 8 (b) and 8 (c) show another example of the joint portion between adjacent steel segments.
One or a plurality of support plates 11 are attached to both ends of the “0” at predetermined intervals.

By doing so, the fixing force at both ends of the joining member 10 is remarkably increased, so that the stress transmission between the steel segments by the joining member 10 can be made more reliable, and the fixing of the joining member 10 can be achieved. Since the length can be reduced, the length of the joining member 10 can be saved. Also, the joining member 1
The installation work of the “0” is also facilitated.

The shear reinforcing steel member 3 is mounted between the outer and inner steel segments 1 and 1 at a predetermined interval in the circumferential direction and the axial direction of the large-section tunnel A, and the shear reinforcing steel member 3 alone is insufficient as a shear reinforcing member. In this case, a necessary amount of the shear reinforcing bar 12 is wound around the reinforcing bar 4 and arranged.

The reinforcing bars 4 are arranged continuously along the main girder 7 in the circumferential direction of the large-section tunnel A near the inner and outer steel segments. In addition, when the main girder 7 of the steel segment 1 is regarded as a tensile steel material that resists the cross-sectional force of the large-section tunnel A, the reinforcing bar 4 has an insufficient amount of reinforcing bar with the main girder 7 alone.

When both the main girder 7 and the skin plate 9 are regarded as tensile steel materials, the amount of reinforcing steel which is insufficient for these two is arranged. The cross-sectional design of the main girder 7 of the steel segment 1 is mainly performed by using the cross-sectional force acting on the single tunnel a and the large cross-section tunnel A as design stress. As the sectional force of the large-section tunnel A at that time, a compressive force due to bending, a tensile force, and a shear force can be considered, but mainly the tensile force is the design stress. Further, the cross-sectional design of the reinforcing steel bar 4 is performed using the cross-sectional force of the large-section tunnel A as a design stress.

In such a configuration, a method of constructing a large-section tunnel according to the present invention will now be described. First, in order to construct the outer shell body 6 of the tunnel A having a large cross section, a plurality of single tunnels a are dug near each other as shown in FIG. 4, for example.

At this time, the ground surface of each single tunnel a is covered with a plurality of steel segments 1 at the tail part of the shield machine. Next, the shear reinforcing steel members 3 are installed at predetermined intervals in each single tunnel a. At that time, the shear reinforcing steel material 3 is
May be installed perpendicular to the material axis, or may be installed obliquely so as to form a truss structure advantageous in strength.

If necessary, cheeks (diagonal members) are attached to the joints between the upper and lower main girders 7 and the shear reinforcing steel members 3 (not shown). Some of the shear reinforcing steel materials 3 are installed as compression reinforcing materials for the steel segments 1. In this case, the shear reinforcing steel materials 3 are installed simultaneously with the steel segments 1.

Next, the adjacent single tunnels a are joined to each other. At this time, the ground around the adjacent single tunnels a, a is improved because it is necessary to prevent collapse at the time of joining. The ground improvement at this time is performed simultaneously with excavation of the single tunnel a, or after excavation of the single tunnel a, or simply a retaining plate which receives the earth pressure of this portion between the adjacent single tunnels a, a (not shown). To prepare for the collapse of the surrounding mountains.

When the soil improvement between the joints is completed, the soil between the single tunnels a, a is removed, and the skin plate 9 of the steel segment 1 provided on each side of the single tunnel a is removed. Adjacent single tunnels a are connected to each other in one space. At that time, the main girder 7 and the vertical ribs 8 may be removed together with the skin plate 9 if necessary. Next, a plurality of joining members 10 are respectively bridged between the ends of the upper and lower steel segments 1 and 1 of the adjacent single tunnel a. Next, a plurality of reinforcing bars 4 are arranged between a plurality of single tunnels a formed in one space continuous in the circumferential direction of the large-section tunnel A in this manner.

The reinforcing steel bars 4 are arranged continuously in the circumferential direction of the large-section tunnel A. Also, in principle, large section tunnel A
Reinforcing bars are also arranged in the axial direction (not shown). When the main girder 7 of the steel segment 1 is regarded as a tensile steel material that resists the section force of the large-section tunnel A, the reinforcing girder 4 arranges a reinforcing bar amount that is insufficient with the main girder 7 alone.

When the skin plate 9 is also considered to be a tensile steel material, the main girder 7 and the skin plate 9 are provided with insufficient reinforcing bars. Further, the reinforcing reinforcing bars 12 are also arranged. Next, when the arrangement of the reinforcing steel bars 4 and the shear reinforcing bars 12 is completed, concrete 5 is poured. Next, when the concrete 5 develops enough strength,
The earth and sand inside the outer shell body 6 is excavated by a general-purpose heavy equipment or the like.
In this manner, a tunnel A having a large cross section that forms a composite structure of steel and reinforced concrete can be constructed from the plurality of steel segments 1, the reinforcing steel bars 4, and the concrete 5.

Since the sectional force acting on the outer shell body 6 having a large cross section is not necessarily uniform in all parts, the steel plate is divided into parts such as the top plate, the side wall and the bottom plate in accordance with the sectional force. A steel / reinforced concrete composite structure including the steel segment 1, the reinforcing bar 4, and the concrete 5, a steel / concrete composite structure including the steel segment 1 and the concrete 5,
Furthermore, labor-saving construction and economic construction can be achieved by using the most appropriate one of the reinforced concrete structures composed of the reinforcing steel bar 4 and the concrete 5.

Steps (1) to (4) are not necessarily performed after excavating the entire single tunnel a, but may be sequentially performed while partially excavating. Embodiment 2 of the Invention FIGS. 9 to 14 show the structure of the joint between the steel segments 1 between the adjacent unitary tunnels a, which will be described in order.

9 (a) to 9 (c) show a case where a plurality of high-strength reinforcing bars, ordinary reinforcing bars, PC steel bars, long bolts, etc. In this case, both ends of the joining member 14 are fixed to the longitudinal ribs 8 by fixing nuts 15, respectively.

In particular, the male male member 16a and the female female member 16b whose contact surfaces are spherical so that the joining member 14 can extend in any direction between the vertical rib 8 and the fixing nut 15. The spherical base 16 is interposed.

A reinforcing rib 17 for transmitting the force of the joining member 14 to the main girder 7 is attached to the vertical rib 8. According to this example, since the joining members 14 joining the steel segments 1 can be oriented in any direction, three-dimensional construction errors occurring in the single tunnels a, a can be easily absorbed, and the construction accuracy can be reduced. Improvement can be achieved.

Further, by directly joining the steel segments 1 with the joining member 14 made of a high-strength reinforcing bar or the like, the stress transmission between the single tunnels a can be performed more reliably.

Next, FIG. 10 shows a plurality of high-strength reinforcing bars or long bolts as shown in FIG. Alternatively, it is joined by a joining member 14 made of a PC steel bar or the like, and the compression side is not joined in particular, but concrete 5 is simply cast. This is particularly intended to save the joining member 14 and save labor in construction.

FIGS. 11 (a) and 11 (b) show a plurality of high-strength rebars as shown in FIG. A compression member 18 made of a shaped steel or the like is provided on the compression side to improve the compression strength on the compression side in particular.

Incidentally, both ends of the compressed steel material 18 are simply butted against the end of the steel segment 1 via a high-strength mortar 19, or the steel member is made of steel by a joining bolt 20 as shown in FIG. It is bolted to the end of the segment 1.

Each of FIGS. 12 and 13 shows an example in which the steel segments 1 are joined to each other when a single tunnel a is lined with a plurality of steel segments 1. FIG. In the figure, the main girder 7 of the steel segment 1 is connected to the joining plate 21 and the plurality of high-strength bolts 2.
2 is a structure in which high-strength bolts are frictionally joined.

FIG. 13 shows a joint plate 23 attached to the end of the steel segment 1 joined by a long bolt 24, and a joint space 23 formed around the long bolt 24 in a filling space 25. This is a structure in which high-strength concrete or mortar 26 is filled.

The filling space 25 is formed by the main girder 7, the skin plate 9, the joint plate 23 and the reinforcing plate 27. By joining the steel segments 1 in this manner, the stiffness of the steel segments 1 and the reinforcing steel bars 4 can be made as close as possible, and the quality of the steel / reinforced concrete composite structure can be significantly improved.

FIGS. 14 (a) and 14 (b) show a single member adjacent to a joining member 28 formed by providing enlarged diameter portions 28a at both ends of a reinforcing bar, a high-strength reinforcing bar, a PC steel bar or the like. The tunnels a are joined together.

In this case, the enlarged diameter portion 28a is for stably transmitting the force to the concrete of the segment, and has a structure in which direct stress transmission between the main girder 7 and the joining member 28 is not considered. .

At this time, the sectional force acting on the upper and lower main girders 7 is basically the vertical main girder 7 located between the upper and lower main girders 7.
Designed to be transmitted to both main girders via A. The vertical main girder 7A is a main girder of a steel segment installed to cover the side of the single tunnel a. Embodiment 3 of the Invention 15 to 17 show an example of a large-section tunnel similarly constructed in a rectangular section. In the figure, a plurality of steel segments 1 are installed on the ground surface of a large-section tunnel A while being joined to each other in the axial direction and the circumferential direction of the large-section tunnel A.

A plurality of reinforcing bars 4 are arranged inside the steel segment 1, and concrete 5 is cast thereafter. Thus, the ground surface of the large-section tunnel A is covered with the outer shell body 6 of the composite steel / reinforced concrete structure constructed to a predetermined thickness from the steel segment 1, the reinforcing steel bar 4, and the concrete 5.

At this time, the steel segment 1 is formed as described in Embodiment 1, and the steel segment 1 and the reinforcing steel bar 4 are installed as described in Embodiments 1 and 2, respectively.
Arrange the bars.

Further, of the reinforcing steel bars 4, the reinforcing steel bars 4 arranged on the steel segment 1 side are the steel segments 1.
Is installed as a resistance member that resists the cross-sectional force of the large-section tunnel A, the shortage of the resistance member is arranged.

[0063]

The present invention has the above-described structure,
In particular, a plurality of steel segments are installed as resistance members that resist the sectional force of a single shield tunnel and the sectional force of a large-section tunnel, and reinforcing bars that are far less expensive than steel segments are arranged as insufficient resistance members. Therefore, it is not necessary to increase the cross-sectional strength of the outer shell body by increasing the size of the joint between the steel segments and the steel segments, thereby achieving labor-saving construction, economical construction, and further cost reduction.

Further, since the single tunnels are joined to each other with joining members, and a plurality of reinforcing steel bars are continuously arranged in the circumferential direction of the large-section tunnel, the outer shell body lining the ground of the large-section tunnel is provided. Proof stress and deformation performance can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing an example of a large-section tunnel.

FIG. 2 is a partial perspective view of an outer shell body lining the inner periphery of the large-section tunnel.

FIG. 3 is a partial cross-sectional view in the tunnel axial direction of an outer shell body lining the inner periphery of a large-section tunnel.

FIG. 4 is a cross-sectional view in a direction perpendicular to the axis of a plurality of single tunnels excavated to construct an outer shell body.

FIG. 5 is a partial perspective view of a large-section tunnel showing an example of arrangement of steel segments, reinforcing bars, joining members, and the like.

FIGS. 6 (a), (b), and (c) are partial perspective views showing an example of a steel segment.

7A and 7B show junctions between single tunnels adjacent to each other in the circumferential direction of the large-section tunnel, FIG. 7A is a sectional view in the tunnel circumferential direction, FIG. 7B is a sectional view taken along the line II in FIG. () Is a cross-sectional view taken along a roll line in (b).

8A and 8B show junctions between single tunnels adjacent to each other in the circumferential direction of the large-section tunnel, FIG. 8A is a sectional view in the tunnel circumferential direction, FIG. 8B is a sectional view taken along the line II in FIG. () Is a cross-sectional view taken along a roll line in (b).

9A and 9B show a joining portion between single tunnels adjacent to each other in the circumferential direction of the large-section tunnel, FIG. 9A is a sectional view in the tunnel circumferential direction, FIG. 9B is a perspective view showing an installation state of the joining member, and FIG.
FIG. 3 is a cross-sectional view of a fixing unit.

FIG. 10 is a cross-sectional view showing a junction between unit tunnels adjacent in the circumferential direction of a large-section tunnel.

FIG. 11A is a cross-sectional view showing a joint between adjacent single tunnels in a circumferential direction of a large-section tunnel, and FIG. 11B is a partial cross-sectional view showing a joint of a compressed steel material.

FIG. 12 is a cross-sectional view showing a junction between unit tunnels adjacent to each other in the circumferential direction of the large-section tunnel.

FIG. 13 is a cross-sectional view showing a junction between unit tunnels adjacent to each other in the circumferential direction of the large-section tunnel.

FIG. 14A is a cross-sectional view showing a junction between single tunnels adjacent to each other in the circumferential direction of the large-section tunnel, and FIG. 14B is a cross-sectional view showing a structure of a fixing portion of the bonding member.

FIG. 15 is a sectional view showing an example of a large-section tunnel.

FIG. 16 is a partial perspective view of an outer shell body lining the inner periphery of the large-section tunnel.

FIG. 17 is a partial cross-sectional view in the tunnel axis direction of an outer shell body lining the inner periphery of the large-section tunnel.

FIG. 18 is a cross-sectional view of an outer shell skeleton lining the inner periphery of the large-section tunnel and a plurality of single tunnels excavated to construct the outer shell skeleton of the large-section tunnel.

FIG. 19 is a perspective view showing an example of a conventional steel segment.

[Explanation of symbols]

 A Large section tunnel a Single tunnel 1 Steel segment 2 Lattice frame 3 Shear reinforcing steel 4 Reinforcing steel 5 Concrete 6 Outer shell 7 Main girder 7a Guide rib 7b Uneven part 8 Vertical rib 8a Reinforcement rib 9 Skin plate 10 Joining Member 11 Support plate 12 Shear reinforcement 13 Concave part 14 Joining member 15 Fixing nut 16 Spherical pedestal 16a Pedestal male fitting 16b Pedestal female fitting 17 Reinforcement rib 18 Compressed steel material 19 Mortar 20 Joining bolt 21 Joining plate 22 Joining bolt 23 Joint plate 24 Long bolt 25 Filling space 26 Concrete or mortar 27 Reinforcement plate 28 Joining member 28a Large diameter portion

Claims (8)

[Claims] After excavating a plurality of single shield tunnels while lining them with steel segments, concrete is poured into the single shield tunnels to construct a large-section shell body. In the method of constructing a large section tunnel by excavating earth and sand in a skeleton, a steel segment is installed as a resistance member that resists a section force of a single shield tunnel and a large section tunnel, and the single shield tunnel is installed. A method of constructing a large section tunnel, wherein a plurality of reinforcing bars are arranged inside the inside as reinforcing members for resisting the section force of the large section tunnel. 2. Construction of a large-section tunnel by digging a tunnel while lining with a plurality of steel segments and then pouring concrete to a predetermined thickness inside the steel segment. In the method, a steel segment is installed as a resistance member that resists the cross-sectional force of the tunnel, and a plurality of reinforcing bars are arranged in the concrete as a resistance member that resists the cross-sectional force of the tunnel. Tunnel construction method. 3. The method according to claim 1, wherein the single shield tunnels are joined with a plurality of joining members. 4. The reinforcing reinforcing bar according to claim 1, wherein when the steel segment is installed as a resistance member for resisting the sectional force of the large-section tunnel, an insufficient reinforcing member is arranged. Or the construction method of the large section tunnel described in 3. 5. The reinforcing reinforcing bar is continuously arranged in the circumferential direction of the tunnel.
The construction method of the large section tunnel described. 6. The construction of a large-section tunnel according to claim 1, wherein the steel segment has an uneven portion or a plurality of slip stoppers for increasing the adhesion to concrete. Construction method. 7. The method for constructing a large-section tunnel according to claim 3, wherein both ends of the joining member are fixed to a steel segment or surrounding concrete. 8. The large joint according to claim 3, wherein the joining member is formed of a reinforcing bar, a high-strength reinforcing bar, a PC steel rod, a PC steel stranded wire, or a steel material. Construction method of cross section tunnel.