JPH0711897A - Tunnel structure - Google Patents

Abstract

PURPOSE:To resist the earth pressure of a banking having large depth sufficiently while facilitating the execution of work and shortening the term of work. CONSTITUTION:A plurality of concrete slabs 12, in which reinforcements 11 are projected to an outer circumferential surface and which are made of precast concrete, are connected and a tunnel wall body 13 is constituted, concrete 14 is placed on the outer circumferential surface of the tunnel wall body 13 on a field while covering the reinforcements 11, and a banking 3 is carried out while covering concrete 14 and tunnel structure is constructed. The concrete slabs 12 can be lightened, the execution of work is facilitated, and the term of work can also be shortened. The tunnel wall body 13 as the composite structure of the concrete slabs 12 and placed concrete 14 has structure capable of sufficiently resisting the earth pressure of the banking 3 having large depth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure suitable for, for example, a tunnel of a type in which a cut-through road is replaced with a tunnel road and an embankment is applied thereon.

[0002]

2. Description of the Related Art When a cut-through road is made into a tunnel road and the surface of the embankment obtained after embankment is applied to it, for example, is converted into a leisure facility, the tunnel wall can withstand the earth pressure of the embankment. The demand becomes more severe as the embankment has a particularly large depth (for example, a covering thickness of about 10 to 20 m). The wall of the tunnel has conventionally been constructed by casting concrete on site or simply connecting precast concrete plates.

[0003]

If all the tunnel walls are cast on site, the formwork required for casting will require sufficient reinforcement to prevent collapse and an enormous amount of concrete will be required. Will lead to the prolongation of. Moreover, when precast concrete is used, since it is heavy enough to withstand earth pressure, transportation and installation work are extremely difficult and impractical.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a tunnel structure capable of withstanding the earth pressure of a large depth of embankment while facilitating the construction and shortening the construction period. I am trying.

[0005]

The present invention has been made in order to achieve the above-mentioned object, and a plurality of precast concrete slabs incorporating rebars projecting over substantially the entire outer peripheral surface are connected to each other. The concrete wall is characterized in that the concrete wall is cast on the outer peripheral surface of the concrete slab on the spot to obtain a tunnel wall body, and then the tunnel wall body is covered with embankment. Further, the reinforcing bar is constituted by a dowel bar embedded in the concrete slab, and a main bar and a force distributing bar fixed to the dowel bar and extending in the circumferential direction and the axial direction of the tunnel wall body.

[0006]

According to the tunnel structure of the present invention, the tunnel wall is a composite structure of the precast concrete slab and the cast concrete, and the concrete slab may have a thickness that can withstand the pressure of the cast concrete. Therefore, since it is possible to reduce the weight of the concrete slab, it is relatively easy to transport and install, and since the required amount of concrete is added to form a composite (structure), the construction is easy and the construction period is short. Be promoted. Further, the tunnel wall body obtained by placing concrete on the outer peripheral surface of the concrete slab by casting concrete and integrating them together has a structure capable of sufficiently withstanding a large earth pressure as a whole.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which a cut-through road, which was previously a cut-through road, is passed through a road 2 in a tunnel 1 constructed according to the present invention, and a fill 3 is applied on the tunnel 1. Reference numeral 4 indicates the slope of the previous cut-through road, and 5 indicates the existing ground.

As shown in detail in FIG. 2, the tunnel 1 has a plurality of precast concrete slabs 12 in which reinforcing bars 11 projecting over substantially the entire outer peripheral surface are incorporated and connected in the tunnel length direction. Concrete wall 13 is cast on the entire surface to cover the reinforcing bar 11 to obtain a tunnel wall 14. In this case, the concrete slab 12 is a circular arc slab that forms a cross section of the tunnel 1 with one set on the left and right, and one end of each of the base concrete 1
5, the other end surfaces are in contact with each other and connected, and this connecting portion serves as the top.

The concrete slab 12 is made lightweight by setting the slab thickness to an extent that it can withstand the pressure of the cast concrete 13. In this case, the reinforcing bar 11 is
As shown in FIG. 3 and FIG. 4, a U-shaped perforation 11a embedded in the concrete slab 12 and protruding in the radial direction thereof.
A main bar 11b that is welded to the inside of the gibber 11a and extends in the circumferential direction of the concrete slab 12, and a force distribution bar 11c that is welded to the inside of the main bar 11b and extends in the axial direction of the concrete slab 12 (tunnel 1) Three types are assembled, and the projecting length of the gibber streak 11a from the concrete slab 12 is set to be slightly longer than the thickness of the concrete slab 12. When the concrete 13 is poured, it is carried out by using a mold such as a metal platform, and is integrated with the concrete slab 12 through the reinforcing bar 11. Casting concrete 13
Has a covering thickness with respect to the reinforcing bar 11 set to be slightly thinner than the thickness of the concrete slab 12.

In order to construct the tunnel 1, the plurality of concrete slabs 12 are transported and installed, the concrete 13 is poured and cured, and the embankment 3 is formed. On the surface of the embankment 3, for example, leisure facilities are constructed.

According to the tunnel 1 having the above structure, the reinforcing bar 11
Since the concrete slab 12 incorporating the is designed to be lightweight, it is relatively easy to carry and install the concrete slab 12. The tunnel wall 14 obtained by placing the concrete 13 on the outer peripheral surface of the concrete slab 12 by placing the concrete 13 and integrating them is a composite structure of the concrete slab 12 and the cast concrete 13. As a whole, the structure can sufficiently withstand a large earth pressure, and the embankment 3 will perform its function over a long period of time even at any large depth.

[0012]

As described above, according to the tunnel structure of the present invention, a tunnel wall body is constructed by connecting a plurality of precast concrete slabs into which reinforcing bars protruding almost all over the outer peripheral surface are incorporated. On the outer peripheral surface of this tunnel wall,
It is characterized in that it is made by embankment after the concrete is cast on site, covering the rebar, and that the concrete slab can be made lighter, so that it can be transported and installed relatively easily, and the concrete can be placed. Since the amount of concrete is relatively small, the construction can be facilitated and the construction period can be shortened.Moreover, it can be obtained by placing concrete on the outer peripheral surface of the concrete slab covering the reinforcing bars and integrating them. The tunnel wall body provided has an effect of having a structure capable of sufficiently withstanding the earth pressure of the embankment of any large depth.

[Brief description of drawings]

FIG. 1 is an overall front view of a tunnel according to an embodiment of the present invention.

FIG. 2 is a front view showing details of the tunnel of the embodiment.

FIG. 3 is a perspective view showing a structure of a reinforcing bar.

FIG. 4 is a side view of the same.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Tunnel, 3 ... Embankment, 11 ... Reinforcing bar, 11a ... Gibel bar, 11b ... Main bar, 11c ... Distribution bar, 12 ... Concrete plate, 13 ... Casting concrete, 14 ... Tunnel wall.

Claims (2)

[Claims] 1. A plurality of precast concrete slabs in which reinforcing bars protruding into substantially the entire outer peripheral surface are incorporated,
A tunnel structure in which concrete is cast on the outer peripheral surface of the concrete slab on the spot to obtain a tunnel wall body, and thereafter, the tunnel wall body is covered and embankment is applied. 2. The rebar is composed of a dowel reinforcement embedded in the concrete slab, and a main reinforcement and a distribution reinforcement fixed to the dowel reinforcement and extending in the circumferential direction and the axial direction of the tunnel wall. Claim 1 characterized by the above.
The described tunnel structure.