JP2001003691A - Lining construction of tunnel with rectangular cross section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lining construction of a tunnel with a rectangular cross section that enables a tunnel with a rectangular cross section to be constructed at low cost by use of inexpensive concrete segments. SOLUTION: At the ceiling part (a), floor part, and right and left sidewall parts (c) of a tunnel A dug into a rectangular cross section, end segments 1 are installed at corners on the natural ground, a central segment 2 is installed in the center between the end segments 1, 1, and a plurality of intermediate segments 3 are installed between each end segment 1 and the central segment 2, in such a manner that the segments 1, 2, 3 adjoin to one another along the circumferential and axial directions of the tunnel A. At the ceiling part (a), the floor part and the right and left sidewall parts (c), a plurality of tensioning members 4 are each fixed at both ends to the end segments 1 and are installed in the form of a catenary curve that projects inwards of the tunnel A, to introduce prestress of a predetermined magnitude in the circumferential direction of the tunnel A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lining structure for a tunnel having a rectangular cross section, which is constructed on the ground of a tunnel dug into a rectangular cross section.

[0002]

2. Description of the Related Art For the purpose of using a tunnel, it is often desirable that the cross section of the tunnel is rectangular rather than circular because the so-called dead space is small and the space can be used effectively.

Until now, a square (box-shaped) tunnel has been constructed by a hand-digging type open shield. However, since a bending moment acting on the lining is larger than that of a circular shield, a steel tunnel is used. Segments (steel shell segments) are used, and temporary or permanent middle pillars are arranged as necessary.

[0004]

However, depending on the size of the tunnel, the steel shell segment is more expensive than the concrete segment, and in the case where the middle pillar is arranged, its construction (or removal in the case of temporary construction) depends on its construction. There were problems such as prolonged construction period and high costs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a rectangular cross-section tunnel covering which can be constructed at a low cost by using inexpensive concrete segments. The purpose is to provide an engineering structure.

[0006]

As a means for solving the above-mentioned problems, a lining structure of a rectangular cross-section tunnel according to the present invention is characterized in that a concrete segment is formed on the ground of a tunnel having a rectangular cross-section. Are installed adjacent to each other in the circumferential direction and the axial direction of the tunnel, and a plurality of tendon members are inserted into at least one of the ceiling portion, the floor portion, and the left and right side wall portions of the tunnel so as to extend in the circumferential direction of the tunnel. Introduce prestress.

According to a second aspect of the present invention, in the lining structure of the first aspect, the tension member has a corner portion of the tunnel as a fixed end and is provided in a suspended curve shape projecting inward of the tunnel. Claim 3
In the lining structure of the first or second aspect, the tension member is installed so as to be exposed inside the segment.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 5 show an example of the present invention, in which a ceiling portion a of a tunnel A dug into a rectangular cross section,
In the floor portion b and the left and right side wall portions c, the end segments 1 are provided at each corner of the ground.
A central segment 2 is provided at a central portion between the two, and a plurality of intermediate segments 3 are provided between each end segment 1 and the central segment 2 so as to be adjacent to each other in the circumferential direction and the axial direction of the tunnel A. .

Further, the ceiling part a and the floor part b of the tunnel A
In each of the left and right side wall portions c, a plurality of tendon members 4 are continuously installed in the circumferential direction of the tunnel A between the end segment 1, the center segment, and the middle segment 3 at both ends, respectively. A large amount of prestress is continuously introduced in the circumferential direction of the tunnel A between the end segment 1, the center segment 2 and the middle segment 3 at both ends by the tendon 4.

In this way, a segment ring having a rectangular cross section is formed from the end segment 1, the center segment 2 and the plurality of intermediate segments 3 at both ends, and these segment rings are installed adjacent to each other in the axial direction of the tunnel A. As a result, a segment lining (segment lining body) that is continuous in the axial direction of the tunnel A is formed. The tendon may be inserted also in the axial direction of the tunnel A.

The end segments 1 adjacent to each other in the axial direction of the tunnel A, the center segments 2 and the intermediate segments 3 are connected by a plurality of connection bolts 5.

The end segment 1 has an L-shape when viewed in the axial direction of the tunnel A, and has a substantially groove-shaped cross section that opens inward of the tunnel A. In addition, the corner portion 1a is formed particularly thick, through holes 1b for passing the ends of the tension members 4 are formed at predetermined intervals, and the ends of the tension members 4 are formed at the ends of the through holes 1b. A concave portion 1c for fixing is formed.

Further, bolt holes 1d for inserting connecting bolts 5 for connecting end segments 1 adjacent to each other in the axial direction of the tunnel A are formed at predetermined intervals on both axial sides of the tunnel A.

The center segment 2 is formed in a rectangular parallelepiped having substantially the same cross-sectional size as the end segment 1. Also,
Through hole 2 for passing tendon 4 inward of tunnel A
a are formed at predetermined intervals so as to penetrate in the circumferential direction of the tunnel A, and an opening 2b penetrating in the circumferential direction of the tunnel A is formed near the outside thereof.

Further, a plurality of bolt holes 2c are formed through the axial direction of the tunnel A so as to insert connecting bolts 5 for connecting the central segments 2 adjacent to each other in the axial direction of the tunnel A. The bolt hole 2c communicates with the opening 2b so that the connection bolt 5 can be tightened at the opening 2b. The central segment 2 formed in this way is installed at a substantially central portion between the end segments 1 and 1 at both ends.

The intermediate segment 3 is formed in a substantially groove-shaped cross section opening inward of the tunnel A, and is formed to have substantially the same cross-sectional size as the central segment 2. Further, a plurality of ribs 3a that are continuous in the axial direction of the tunnel A are provided on the inner side at a predetermined interval, and the ribs 3a are formed gradually longer toward the center segment 2 side. Also, rib 3
A groove 3b through which the tendon 4 passes is formed at a predetermined interval at the tip end of "a".

Further, bolt holes 3c are formed on both sides of the tunnel A in the axial direction for passing connecting bolts 5 connecting the intermediate segments 3 adjacent to each other in the axial direction of the tunnel A.

The intermediate segment 3 thus formed
Are provided adjacent to each other between the end segment 1 and the center segment 2 at both ends according to the diameter of the tunnel A. Both ends of the tension member 4 are inserted into the through holes 1b of the end segments 1 at both ends, and are fixed in the concave portions 1c by the fixing nuts 6, respectively.

The central portion of the tension member 4 is inserted into the through hole 2a of the central segment 2, and both side portions are bridged by the concave grooves 3b of the rib 3a of each intermediate segment 3. In this case, since the ribs 3a are gradually formed longer at the center portion located near the center segment 2, the tendon 4 is arranged in a suspension curve shape projecting inward of the tunnel A.

The tension members 4 are installed in a so-called out-cable system, which is exposed in the tunnel A. By installing in this manner, the tendon 4 can be installed even after the segments are assembled, so that the workability is extremely good.

The tension members 4 may be arranged diagonally, for example, as shown in FIG. As a method of introducing the prestress, for example, both ends of the tendon 4 are fixed to the concave portions 1c of the end segments 1 with fixing nuts 6, respectively, and the tendon 4
After the tension is applied to introduce prestress, the central portion of the tension member 4 is fixed to the central segment 2.

Further, a prestress is introduced only at the time of assembling the segment as the primary lining, and the inside of the segment is reinforced with the reinforced concrete as the secondary lining, and then the prestress is released to form a reinforced concrete structure lining. You can also.

FIGS. 6 (a) and 6 (b) show another example of the present invention. In each of the examples, a tension member 4 is provided on each of a ceiling portion a, a floor portion b and left and right side wall portions c of a tunnel A. Are fixed to the end segments 1 and arranged linearly.

At this time, as shown in FIG.
There is a case where the tendon 4 is installed, and a case where the tendon 4 is connected by a connecting member 7 such as a coupler as shown in FIG. In the example of (2), the tendon 4 can be easily installed, and both ends of the tendon 4 can be fixed, and the prestress can be introduced by tension at the central portion, so that the workability is good.

Furthermore, the tendon 4 may be installed after the segments are assembled, or may be installed in each segment in advance.

[0026]

The present invention has the above-described structure,
Plural concrete segments are installed on the inner periphery of a tunnel with a rectangular cross-section, installed adjacent to each other in the circumferential direction and axial direction of the tunnel, and tension members are inserted through the ceiling, floor, and left and right side walls. Since a predetermined large amount of prestress is introduced in the circumferential direction, the inner circumference of the rectangular cross-section tunnel can be lining at extremely low cost by using a cheap concrete segment.

Further, since the tension members are provided at the ceiling, floor, and side wall portions of the rectangular cross-section tunnel at the corners of the tunnel as fixed ends and are respectively provided in the form of a suspension curve projecting inward of the tunnel. In particular, the bending moment acting on the cross section of the tunnel can be very effectively reinforced.

Further, since the tendon is exposed and installed inside the segment, the tendon can be easily installed and the workability is extremely good.

[Brief description of the drawings]

FIG. 1 shows an example of a concrete lining composed of a plurality of segments, (a) is a partial perspective view, and (b) is a front view.

FIGS. 2A and 2B show examples of arrangement of tendon members, wherein FIG. 2A is a partial cross-sectional view of a concrete lining, and FIG.

FIG. 3 shows an end segment, (a) is a perspective view thereof,
(B) is a sectional view, and (c) is a front view.

4A and 4B show an intermediate segment, wherein FIG. 4A is a perspective view, FIG. 4B is a sectional view, and FIG. 4C is a sectional view.

5A and 5B show a central segment, in which FIG. 5A is a perspective view and FIG. 5B is a sectional view.

FIGS. 6A and 6B are cross-sectional views showing other examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 End segment 1a Corner 1b Through hole 1c Depression 1d Bolt hole 2 Center segment 2a Through hole 2b Opening 2c Bolt hole 3 Intermediate segment 3a Rib 3b Concave groove 3c Bolt hole 4 Tensile material 5 Connecting bolt 6 Fixing nut 7 Connecting member

Claims (3)

[Claims] 1. A plurality of concrete segments are installed adjacent to each other in a circumferential direction and an axial direction of a tunnel at the ground of a tunnel having a rectangular cross-section, and are formed on a ceiling portion, a floor portion, and left and right side wall portions of the tunnel. A lining structure for a tunnel having a rectangular cross section, wherein a plurality of tendon members are inserted into at least one place to introduce prestress in a circumferential direction of the tunnel. 2. The lining structure of a tunnel having a rectangular cross section according to claim 1, wherein the tendon is fixed at a corner of the tunnel at a fixed end and is arranged in a suspended curve shape projecting inward of the tunnel. 3. The lining structure of a rectangular cross-section tunnel according to claim 1, wherein the tension member is installed so as to be exposed inside the segment.