JP3999853B2 - How to build a tunnel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing a tunnel whose tunnel cross section has an oval or vertically long shape.
[0002]
[Prior art]
In the conventional tunnel, when constructing the tunnel of the up line and the down line, it is necessary to construct two different tunnels or to construct a tunnel having a large cross section.
However, it is difficult to build two tunnels or large-section tunnels when building tunnels under existing roads with limited space. Although there was a demand for technology to construct a tunnel, there was no construction example yet.
[0003]
Therefore, as a method of constructing a tunnel under an existing road with a limited space according to the prior art, it is necessary to make the tunnel two stories or plural stories.
As a construction method for that purpose, a method is considered in which a tunnel is constructed by digging up sequentially from above, and placing secondary lining concrete after excavation is completed.
[0004]
However, this method may cause unforeseen circumstances such as the ground collapsing into the tunnel during excavation and may damage existing surrounding structures.
[0005]
[Problems to be solved by the invention]
The present invention has been made in order to solve the problems expected as problems of the above-described prior art, and provides a method for constructing a tunnel safely and under an existing road in a limited space. Objective.
[0006]
[Means for Solving the Problems]
In the method of constructing the tunnel, the construction of the upper half section of the tunnel frame including the intermediate floor slab formed at the lower portion of the tunnel side wall is completed in advance of the entire section, and then the lower half of the upper half section is excavated, A tunnel construction method characterized by constructing a lower half section of a tunnel frame below the mid-floor plate integrally with the upper half section and constructing a two -story tunnel, and also constructing the upper half section Is constructed in the order of construction of primary reinforcement, excavation, support, foot pile and floor slab, and construction of the lower half section is conducted in the order of construction of horizon, excavation, support, large back excavation, and invert. This is a tunnel construction method.
[0007]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
Hereinafter, an embodiment for constructing a two-story tunnel will be described with reference to the drawings.
[0008]
<A> Outline of tunnel construction FIG. 1 is a cross-sectional view of a tunnel completed by the tunnel construction method according to the present invention.
In the construction of a two-storied egg-shaped or long-section tunnel 1 having a vertically long shape, first, primary reinforcement 4 is performed, excavation up to the first and second benches, support work 2, foot pile 3, and secondary covering Carry out the work 5 and complete the upper half cross section 7 of the mid-slab 6 or more ahead of the whole section.
Subsequently, excavation of the 3rd and 4th benches, support work 2, foot pile 3, and secondary lining 5 were carried out, and the lower half section 8 part below the middle floor slab 6 was constructed, and finally the invert concrete 9 was applied. To complete the construction of the tunnel 1 for all sections.
[0009]
<B> Excavation of 1st bench FIGS. 2 to 4 are cross-sectional views showing excavation up to the 1st bench, slipping out, steel support construction, and shotcrete placement.
FIG. 2 shows a situation where the excavator 10 excavates a point advanced from the point where the primary reinforcement 4, the support 2, and the foot pile 3 have already been completed. FIG. FIG. 4 shows a situation where a new support work 2 is built in the cross section of the tunnel after excavation and the primary reinforcement 4 is performed by the concrete pump car 12.
[0010]
<C> Two-stage bench excavation FIGS. 5 to 7 are cross-sectional views showing excavation up to the second-stage bench, slipping, steel support construction, and shotcrete placement.
In FIG. 5, before performing the two-stage bench excavation, the foot pile 3 is driven from the front of the face, and the following operations are performed in the same manner as the first-stage bench excavation.
[0011]
<D> Construction of the middle floor slab and primary lining After the completion of the two-stage bench excavation, as shown in FIG. 8, the primary lining 4 of the newly dug portion is constructed, and further the middle floor slab 6 is constructed.
As described above, the primary reinforcement 4, the first-stage bench excavation, the second-stage bench excavation, and the construction of the mid-floor slab 6 are performed in advance over the entire section.
With this construction, the upper floor part of the two-story tunnel is completed.
Further, since the mid-slab slab 6 (corresponding to the slab at the center of the tunnel) restrains the protrusion of the side wall, the stability of the side wall can be greatly improved.
[0012]
<E> Three-stage bench excavation FIGS. 9 and 10 are cross-sectional views showing the excavation order of the three-stage bench excavation.
In the case of three-stage bench excavation, as shown in FIG. 9, first, the tsubo portion 13 (both side wall portions) is excavated by the excavator 10 and the support work 2 is subsequently built.
Thereafter, as shown in FIG. 10, the excavator 10, the dump 11, and the excavator 15 complete the excavation and slippage of the large back portion 14.
[0013]
<F> Four-stage bench excavation FIGS. 11 and 12 are cross-sectional views showing the work status of four-stage bench excavation.
The 4-stage bench excavation will proceed in the same way as the 2-stage bench excavation.
[0014]
<G> Invert concrete placement Finally, as shown in FIG. 1, the invert concrete 9 is placed, and the construction of the tunnel 1 in the entire section is completed.
[0015]
Second Embodiment of the Invention
FIG. 13 is a second embodiment and shows a cross-sectional view of a completed three-story tunnel.
In this embodiment, a foot pile 3 is placed further below the first embodiment, and an intermediate floor slab 6 is constructed to construct a three-story tunnel.
About a construction method, since it is a repetition of 1st Example, description is abbreviate | omitted.
[0016]
【The invention's effect】
Since the present invention has been described above, the following effects can be obtained.
<A> Since it is a two-story or multi-story large-section tunnel having an oval or vertically long shape, a plurality of tunnels can be constructed under an existing road in a limited space.
<B> Since the first stage bench is constructed in advance of all sections and the primary reinforcement is performed, safe work can be performed.
<C> Since the middle floor slab (corresponding to the slab at the center of the tunnel) restrains the protrusion of the side wall, the stability of the side wall can be greatly improved.
<D> Since the protrusion of the natural ground on the side wall is restrained, the influence of subsidence, inclination, etc. on the adjacent existing structure can be eliminated.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a tunnel completed by a tunnel construction method according to the present invention.
FIG. 2 is a cross-sectional view showing the state of excavation up to the first stage bench.
FIG. 3 is a transverse cross-sectional view showing the situation of slippage.
FIG. 4 is a cross-sectional view showing a steel support construction, shotcrete placement, and foot pile placement situation.
FIG. 5 is a cross-sectional view showing a state of excavation up to a two-stage bench.
FIG. 6 is a cross-sectional view showing the situation of slipping out.
FIG. 7 is a cross-sectional view showing the steel support construction, the shotcrete placement, and the foot pile placement situation.
FIG. 8 is a cross-sectional view in which a middle floor slab of a newly dug portion is constructed after completion of excavation of a two-stage bench.
FIG. 9 is a cross-sectional view showing a situation where a horizon portion (both side wall portions) is first excavated for excavating a three-stage bench.
FIG. 10 is a cross-sectional view showing a situation where a large back portion is being excavated and displaced.
FIG. 11 is a cross-sectional view showing the work status of four-stage bench excavation.
FIG. 12 is a cross-sectional view showing the situation of slipping out of the above.
FIG. 13 is a cross-sectional view of a completed three-story tunnel according to the second embodiment.

Claims (2)

In the method of building a tunnel,
Completed the construction of the upper half section of the tunnel frame including the mid-floor formed at the bottom of the tunnel side wall in advance for all sections,
Subsequently, the lower half section of the upper half section is excavated, and the lower half section of the tunnel frame below the mid-slab is constructed integrally with the upper half section, and a two -story tunnel is constructed.
How to build a tunnel. In the method of building a tunnel,
Completed the construction of the upper half section of the tunnel frame including the mid-floor formed at the bottom of the tunnel side wall in advance for all sections,
Subsequently, the lower half of the upper half section is excavated, and the lower half section of the tunnel frame below the mid-slab slab is constructed integrally with the upper half section , and a two -story tunnel is constructed,
The upper half section is constructed in the order of primary reinforcement, excavation, support, footpile, and mid- slab,
The construction of the lower half section is characterized by the construction sequence of horizon excavation, support work, large back excavation, invert construction,
How to build a tunnel.

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