JP6872931B2 - Invert construction method - Google Patents

Description

The present invention relates to an invert construction method.

In the tunnel after operation, the roadbed may rise due to blistering for some reason. As a countermeasure against board blisters, it is most effective to perform inverting on the part where board blisters occur.
When performing inverts in a tunnel in service, it is common to adopt so-called half-split construction, in which excavation, placing / curing of invert concrete, and backfilling are performed one side at a time. However, when half-split construction is carried out in a general road tunnel, it is necessary to reduce the road width when performing invert construction in the central part of the tunnel. On the other hand, in tunnels such as expressways where the width of the road cannot be reduced, it was necessary to carry out the construction in a closed state.

Therefore, in Patent Document 1, as a construction method for performing invert construction in a tunnel in service without requiring traffic closure, left and right inverts excluding the central portion are constructed and inserted at a location corresponding to the central portion of the invert. A method of connecting the left and right inverts with a steel pipe is disclosed.
Further, in Patent Document 2, the left and right inverts excluding the central portion are constructed, and when one invert is constructed, concrete is formed in the gap formed by extracting the soil mass from the position corresponding to the central portion of the invert. The construction method for connecting the left and right inverts at the center of the tunnel is disclosed.

Japanese Unexamined Patent Publication No. 2014-111861 Japanese Unexamined Patent Publication No. 2016-102369

In the invert construction method of Patent Document 1, the structure of the invert is complicated and it takes time and effort to press-fit the steel pipe, so that the construction period becomes long.
Similarly, in the invert construction method of Patent Document 2, the construction period becomes long because it takes time and effort to extract the soil mass. In addition, since the underside of the road in service is excavated, it is necessary to carry out the construction carefully.
From this point of view, it is an object of the present invention to propose an invert construction method capable of performing construction safely and at an early stage.

The invert construction method of the present invention for solving the above problems includes a pre-construction step in which one side of the center of the tunnel cross section is in service and the other side is inverted, and a state in which the other side of the center of the tunnel cross section is in service. The so-called half-split construction method is adopted, which includes a post-construction process in which invert construction is performed on one side. The pre-construction process is performed with one side of the existing road open as the first temporary passage, the first excavation work for invert excavation on the other side, and the ground exposed by the first excavation work. see write out the invert concrete respect, a first shot設作industry to form the other side invert to cure, the second temporary way road laying the lining plate through支保member on inverting the other side It is equipped with temporary passage work to build a road. In addition, the post-construction process includes the second excavation work for invert excavation on one side and the invert concrete for the ground exposed by the second excavation work as the work to be performed with the second temporary passage open. see write hit a includes a second shot設作industry to form a cured to one side inverted, and a traffic channel construction task of building through path. Then, in the second casting work, the end of the one-side invert is connected to the other-side invert to form a continuous invert from one side to the other, and in the passage construction work, the one-side invert is formed. After backfilling the top and forming one side of the passage, the second temporary passage is removed and the other side is filled on the invert with one side of the passage open as the third temporary passage. It is characterized in that the return and the construction of the other side portion of the passageway connected to the one side portion of the passageway are performed .

According to such an invert construction method, it is possible to construct an invert on a tunnel in service without completely closing the inside of the tunnel. Therefore, it is possible to effectively prevent lifting due to blistering of the board or the like. In addition, since a continuous invert is installed at the bottom of the tunnel, the structure is not complicated and the workability is excellent.

According to the invert construction method of the present invention, tunnel invert can be safely and quickly constructed.

It is sectional drawing which shows the tunnel which concerns on this embodiment. It is sectional drawing which shows the work situation of the preceding construction process, (a) is the first excavation work, (b) is the first placing work. (A) is a cross-sectional view showing a passage temporary construction work of a preceding construction process, and (b) is a cross-sectional view showing a second excavation work of a subsequent construction process. It is sectional drawing which shows the work situation of the follow-up construction process following FIG. 3 (b), (a) is a 2nd casting work, and (b) is a passage construction work. (A) and (b) are cross-sectional views showing the passage construction work following FIG. 4 (b).

In the present embodiment, as shown in FIG. 1, the road tunnel in service (hereinafter, simply referred to as "tunnel 1") is inverted for the purpose of preventing board blistering without completely closing the road. The case where 2 is newly installed will be described.
In the tunnel 1 of the present embodiment, the side wall and the top are covered with the arch-shaped lining concrete 11, the bottom is not provided with an invert, and the existing road 3 is directly constructed on the ground. A central drainage channel 4 is formed in the lower central portion of the existing road 3.

The invert construction method of the present embodiment includes a pre-construction step in which one side (right side in this embodiment) of the tunnel cross-section center C is in service and invert construction is performed on the other side (left side in this embodiment), and a tunnel cross section. This is a so-called half-split construction method, which includes a post-construction step in which invert construction is performed on one side while the other side of the center C is in service.

The pre-construction process includes a first excavation work, a first driving work, and a temporary passage work.
In the preceding construction process, as shown in FIG. 2A, the right side portion of the existing road 3 is opened as a temporary passage 5. In the temporary passage 5, road shoulders 52 and 52 are secured on the left and right sides of the road 51. Safety equipment 6 such as a protective fence is installed at the end of the temporary passage 5 on the C side of the center of the tunnel cross section, if necessary.

In the first excavation work, invert excavation (hereinafter, referred to as "first invert excavation") of the left side portion of the tunnel cross-section center C is performed.
Prior to the first invert excavation, the existing ancillary equipment (evacuation passage, etc.) is removed, and the foot concrete member 21 is formed on the legs of the lining concrete 11 and the support (sprayed concrete or steel support) 12. .. When the construction of the foot concrete member 21 is completed, the bottom of the tunnel 1 is excavated by using an excavator M such as a backhoe. The first invert excavation is performed so as to be on the left side of the center of the road (center C of the tunnel cross section) and to secure a predetermined distance from the central drainage channel 4. That is, in the first invert excavation, the left side portion of the bottom portion of the tunnel 1 is excavated while the right side portion including the central portion of the existing road 3 is left behind. The excavation depth and shape of the first invert excavation are determined according to the cross-sectional shape and dimensions of the newly installed invert 2.

In the first placing work, as shown in FIG. 2B, invert concrete is poured into the ground exposed by the first excavation work, cured, and the left side portion of the invert 2 of the tunnel 1 (left invert 22). ) Is formed. At this time, the left end portion of the left invert 22 is connected to the foot concrete member 21. Also, compact the invert concrete if necessary. The thickness of the invert 2 (left invert 22) is appropriately determined according to the ground conditions and the like. Further, reinforcing bars may be arranged in the invert 2 if necessary.

In the temporary passage work, as shown in FIG. 3A, the temporary passage 5 is constructed on the left invert 22. The temporary passage 5 is formed by laying a lining plate 54 via a support member 53 formed on the left invert 22. The lining plate 54 is laid at a height above the road surface of the road (existing road 3) in a range from the vicinity of the side wall of the tunnel 1 to the central portion of the tunnel cross section. That is, the right end portion of the temporary passage 5 (the lining plate 54 laid at the right end) overhangs the cantilever on the left end portion of the remaining portion of the existing road 3. The structure of the temporary passage 5 is not limited, and may be formed by, for example, constructing a temporary pier along the tunnel axial direction. The temporary passage 5 secures the width required as a passage (the width of the roadway 51 and the left and right shoulders 52 shown in FIG. 2A). In addition, safety equipment 6 such as a protective fence is installed at the end of the temporary passage 5 on the C side of the center of the tunnel cross section, if necessary.

The post-construction process includes a second excavation work, a second driving work, and a passage construction work.
In the post-construction process, as shown in FIG. 3B, the temporary passage 5 formed by the lining plate 54 is opened. In the second excavation work, invert excavation of the central part of the tunnel and the right side (one side) (hereinafter referred to as "second invert excavation") is performed. Prior to the second invert excavation, the existing ancillary equipment is removed, and the foot concrete member 21 is formed on the legs of the lining concrete 11 and the support (sprayed concrete or steel support) 12. When the construction of the foot concrete member 21 is completed, the bottom of the tunnel 1 is excavated by using an excavator M such as a backhoe. At this time, excavation is performed including the lower side of the temporary passage 5 (lining plate 54).

In the second casting work, as shown in FIG. 4A, invert concrete is poured into the ground exposed by the first excavation work, cured, and the invert 2 on the right side of the tunnel 1 (right invert 23). To form. The right end portion of the right invert 23 is connected to the left invert 22 and the right end portion is connected to the footed concrete member 21. Also, compact the invert concrete if necessary.

In the passage construction work, the main road 7 is constructed on the invert 2. First, as shown in FIG. 4B, the upper part of the right invert 23 is backfilled, and the central drainage channel 4 is arranged at the center in the width direction. Next, the right side portion of the main road (traffic route) 7 including the upper part of the central drainage channel 4 is paved. At this time, a gutter of the main road 7 is also laid. When the construction of the right side portion of the main road 7 is completed, as shown in FIG. 5A, the right side portion of the main road 7 is opened as a temporary passage 5, and the support member 53 and the lining plate 54 (FIG. 5). 4 (b)) is removed. Then, as shown in FIGS. 5A and 5B, the left side portion of the tunnel 1 is backfilled, a gutter is laid and paved, and the main road 7 is completed.

As described above, according to the invert construction method of the present embodiment, the invert 2 can be constructed on the tunnel 1 in service without completely closing the inside of the tunnel 1. Therefore, it is possible to effectively prevent the tunnel 1 in service from being lifted due to blistering or the like.
Further, since the temporary passage 5 is formed by the lining plate 54 laid via the support member 53, the width of the temporary passage 5 is not reduced even in a tunnel having a standard internal cross section. In addition, the central part can be excavated. As a result, continuous invert 2 can be applied to the bottom of the tunnel. Further, since the invert 2 is integrally continuous with respect to the crossing direction of the tunnel 1, it is effective as a board blistering countermeasure work and is excellent in stability. Therefore, it is excellent in workability, and by extension, effective measures to prevent board blistering can be taken in a short period of time.
Further, since the lining plate 54 constituting the temporary passage 5 is supported by the support member 53, it is excellent in safety.

The embodiment according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and each of the above-mentioned components can be appropriately modified without departing from the spirit of the present invention.
The tunnel 1 in which the invert 2 is newly constructed is not limited to the road tunnel.
Further, in the above-described embodiment, the case where the left side of the tunnel 1 is constructed first has been described, but the order of construction is not limited, and the right side may be constructed first.

1 Tunnel 2 Invert 3 Existing road 4 Central drainage channel 5 Temporary passage 6 Safety equipment 7 Main road (passage)
C tunnel cross section center

Claims (1)

Pre-construction process in which one side of the center of the tunnel cross section is in service and invert construction is performed on the other side.
This is an invert construction method for a tunnel in service, which comprises a post-construction process in which invert construction is performed on one side with the other side in the center of the tunnel cross section in service.
The pre-construction process is performed with one side of the existing road open as the first temporary passage.
The first excavation work to perform invert excavation on the other side,
See write out the invert concrete against natural ground exposed by said first drilling operation, a first shot設作industry to form the other side invert to cure,
It is provided with a passage temporary work for constructing a second temporary passage by laying a lining plate on the invert on the other side via a support member.
The post-construction process is performed with the second temporary passageway open.
The second excavation work to perform invert excavation on one side and
A second shot設作industry saw write out the invert concrete, to form a cured to one side inverted relative to the natural ground exposed by the second drilling operation,
And the way road construction work to build a through path, equipped with a,
In the second casting operation, the end of the one-sided invert is connected to the other-side invert to form a continuous invert from one side to the other.
In the passage construction work, after backfilling the one-sided invert and forming one side portion of the passage, the second temporary passage is opened with one portion of the passage opened as a third temporary passage. An invert construction method comprising removing a road, backfilling on an invert on the other side, and constructing the other side portion of the passage connecting to one side portion of the passage.

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