JP3544534B2 - Tunnel section widening method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of constructing a tunnel constituting, for example, an underground road, a subway, a sewer, and the like, and more particularly to a tunnel capable of simply constructing a widened section for evacuation, branching, merging, etc. in a part of the tunnel. It is intended to propose a section widening method.
[0002]
[Prior art]
Conventionally, tunnel construction has generally employed a shield method. The shield method is the same because once the shield machine is installed on the excavation path, the shield machine will excavate and construct the tunnel lining, so the tunnel can be constructed without affecting the ground. This is an excellent method for constructing a tunnel with a continuous diameter.
On the other hand, for example, as shown in FIG. 7 and FIG. 8, in addition to the number of lanes of the main road tunnel 1, a widening tunnel 2 for constructing a deceleration lane or an acceleration lane is required at a branch junction of an underground road. The widening of the tunnel cross section at the branch junction of the tunnel is constructed by the open-cutting method including the main line tunnel in the conventional construction technology.
[0003]
When digging the whole, including the main tunnel 1 and the widening tunnel 2, the width reaches several tens of meters and the length reaches approximately several hundred meters, so the occupied width and occupied area required for construction are increased, It had a significant impact on the environment and was an important issue in construction.
For this reason, a tunnel section widening method using a shield method has been considered, in which the area to be constructed by the open-cut method is reduced as much as possible. FIG. 9 shows an example. In the example shown in FIG. 9, the main tunnel 1 is dug by the main shield machine 3, a pier 4 is constructed at the start end position of the widening section, and the side shield machines 5A and 5B are lowered to the underground through the pit 4. The shield machines 5A and 5B are mounted on both sides of the main shield machine 3. The widened section is dug by the composite shield machine in which the side shield machines 5A and 5B are mounted on both sides of the main shield machine 3, and the wide tunnel 2 is constructed. A stand is formed again at the end position of the widening section, and the side shield machines 5A and 5B are removed from underground through the stand.
[0004]
[Problems to be solved by the invention]
The current tunnel widening method has the following disadvantages as disadvantages.
(1) When collectively constructing the widened cross section with a shield machine, a large-scale open-cutting work is involved in assembling and remodeling the shield machine by providing a stand at the end of the widened cross section.
(2) Since the tunnel is excavated by a shield machine having a large tunnel section width, if the tunnel cover is small, there is a high possibility that the ground surface will have an influence such as land subsidence.
[0005]
(3) Since large-scale construction equipment is required for assembling and remodeling the shield machine, it occupies the upper part of the pier (generally, a public road) for a long time, and has a large influence on the ground.
(4) When the tunnel section is expanded underground, large-scale ground improvement work is required, so that the number of days and costs required for the construction are large.
(5) In order to construct a branch junction of a road tunnel, a construction technique for branching is required in addition to a method of widening a tunnel section.
An object of the present invention is to propose a tunnel section widening method capable of constructing a widened portion with a reduced influence on the ground and without large-scale excavation work.
[0006]
[Means for Solving the Problems]
According to claim 1 of the present invention, in the tunnel section widening method of providing a widened tunnel in a partial section of the main tunnel, a main line tunnel lining to be constructed in contact with the widened tunnel is provided at a position where the widened tunnel is to be constructed. An opening surface is arranged toward the virtual construction position, and a wide-width tunnel lining with a substantially U-shaped cross section is constructed, and the main line tunnel is in contact with the top and bottom floor slabs of this wide-width tunnel lining by a shield method. We propose a tunnel section widening method to construct lining.
[0007]
According to a second aspect of the present invention, in the tunnel section widening method according to the first aspect, the widening tunnel lining is constructed by an open-cutting method, and a temporary wall that closes an opening surface of the U-shaped cross section is temporarily provided inside the opening surface, We propose a method of widening the tunnel section, which has the role of a supporting material to join the upper and lower slabs, and bury the earth and sand outside the temporary wall to construct the main line tunnel lining.
According to a third aspect of the present invention, in the widening method of the tunnel section according to the first aspect, the widening tunnel lining is constructed by a shield method, and together with the construction of the widening tunnel lining, a temporary wall that closes the opening surface from the opening surface to the inside is constructed. Then, we propose a method of widening the tunnel cross section, which has the role of a supporting material to join the upper and lower slabs, and bury the earth and sand outside the temporary wall to construct the main line tunnel lining.
[0008]
According to claim 4 of the present invention, in any of the tunnel section widening methods according to claims 1, 2, and 3, the construction for constructing the main line tunnel lining includes the upper floor slab and the lower floor constituting the widening tunnel lining. This paper proposes a tunnel section widening method that uses a shield method that includes both ends of the plate in the cutting area .
[0009]
Furthermore, a wide-width tunnel lining having a U-shaped cross section with one side opened is constructed, and the main line tunnel lining is constructed by making contact with the opening surface of the wide-width tunnel lining having the U-shaped cross section. Thus, the junction between the main tunnel and the widening tunnel can be easily achieved .
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 6 show one embodiment of the tunnel section widening method according to the present invention. This embodiment shows a case where the widening tunnel lining is constructed by the open-cutting method.
That is, as shown in FIG. 1, two continuous retaining walls 12-12 are formed with a gap corresponding to the width of the widened tunnel lining 11. The earth and sand in a portion surrounded by the retaining walls 12-12 is dug, and a widened tunnel lining 11 having a substantially U-shaped cross section is constructed at the bottom thereof. The shape of the widened tunnel lining 11 has a substantially U-shaped cross-sectional shape in which a virtual side is opened when the main line tunnel lining is constructed. Further, a case is shown in which the opening surface side is gradually widened outward, and the structure is such that the bonding strength with the cylindrical main line tunnel lining is enhanced by this shape.
[0011]
A temporary wall 13 is formed inside the widening tunnel lining 11. Further, slide hoods 14 are mounted on the outer sides of the upper deck 11A and the lower deck 11B of the widening tunnel lining 11, respectively. The slide hood 14 is configured such that the slide hood 14 can be freely slid from the inside of the widened tunnel lining 11 to the side where the main line tunnel is constructed through a long hole or the like formed in the widened tunnel lining 11.
The retaining wall 12-12 is removed with the widening tunnel lining 11, the temporary wall 13, and the slide hood 14 attached thereto, and the sand is buried in the upper portion of the widening tunnel lining 11 (see FIG. 2). Numeral 10 indicates backfilled earth and sand. At this time, the portion surrounded by the temporary wall 13 and the opening surface of the widening tunnel lining 11 is also filled with the earth and sand 10.
[0012]
With the earth and sand backfilled and the widening tunnel lining 11 buried in the earth and sand, the shield machine is excavated to a position in contact with the opening surface of the widening tunnel lining 11. FIG. 3 shows this state. A broken line 15 shown in FIG. 3 indicates a shield machine excavation line. The shield machine excavates while cutting a part of the tip of the upper deck 11A and the lower deck 11B of the widening tunnel lining 11. For this purpose, the tops of the upper slab 11A and the lower slab 11B are subjected to construction that does not include reinforcing bars. By constructing the main line tunnel lining 16 while cutting the end portions of the upper floor slab 11A and the lower floor slab 11B in this way, the main line tunnel lining 16 and the widening tunnel lining 11 can be formed as shown in FIG. In particular, it is possible to avoid that the main line tunnel lining 16 and the widening tunnel lining 11 are largely separated from each other, and that an accident in which the earth and sand collapses from the gap portion occurs.
[0013]
Since further the have a sliding hood 14 is provided on each outer side of the top floor plate 11A and the lower deck 11B of expansion width tunnel lining 11, main tunnel lining slides hood 14 is at a position where the main line tunnel lining 16 is constructed 16, the slide hood 14 can also shield a slight gap generated between the main line tunnel lining 16 and the widening tunnel lining 11.
FIG. 5 shows the details. On the outer periphery of the main line tunnel lining 16, a backfill injection material 17 applied by a shield method is arranged. By moving the slide hood 14 toward the main line tunnel lining 16, the tip of the slide hood 14 pierces the layer of the backfill material 17. In this state, a soil improvement agent is injected from an injection pipe built in the slide hood 14, and the soil at the joint between the slide hood 14 and the backfilling material 17 is ground improved (solidified), and the upper floor of the widening tunnel lining 11 is laid. The gap between the plate 11A, the lower deck 11B, and the main line tunnel lining 16 has a waterproof structure. Reference numeral 18 shown in FIG. 5 denotes a waterproofing portion solidified by the ground improving agent.
[0014]
In parallel with obtaining the waterproofing portion 18 by the slide hood 14 in an emergency, the temporary wall 13 provided on the widened tunnel lining 11 and the segment 16A of the main line tunnel lining 16 surrounded by the widened tunnel lining 11 ( 6 (represented by a dotted line in FIG. 6), and a construction for permanently connecting the widening tunnel lining 11 and the main tunnel lining 16 is carried out, whereby the main tunnel 1 and the widening tunnel 2 shown in FIG. You can get a tunnel that communicates with.
Although the case where the widening tunnel lining 11 is constructed by the open-cutting method has been described above, the widening tunnel lining 11 can also be constructed by the seeding method. When constructing the widening tunnel lining 11 by the shield method, a shield machine whose excavation surface is set to the cross-sectional shape of the widening tunnel is prepared, and segments are spread around the excavation simultaneously with excavation. In this case, by constructing the temporary wall 13 together with the widening tunnel lining 11, the widening tunnel lining 11 and the temporary wall 13 shown in FIG. 2 can be constructed underground. Since the construction method after the state shown in FIG. 2 is constructed is the same as the construction method shown in FIGS. 3 to 5, further description is omitted here.
[0015]
【The invention's effect】
As described above, according to the present invention, the widened tunnel lining 11 having a substantially U-shaped cross section is constructed and prepared in advance, and the main line tunnel lining 16 is formed along the opening surface of the widened tunnel lining 11. Since the widening part is constructed by the shield method, a part of the main line tunnel lining 16 is removed, and the widening tunnel and the main line tunnel are connected to each other, the widening part can be provided in the tunnel by simple construction. In particular, when the widening tunnel lining 11 is constructed by the open-cutting method, since the width is about 10 meters and the length is about several 100 meters, the cut-off area can be reduced compared to the conventional open-cut method. , The influence on the ground can be reduced. In addition, when constructing a wide tunnel with a length of about several hundred meters, it is conceivable to construct with a shield method, but it is more costly to adopt open cut method than to construct a small section using a shield machine. Can be done at low cost.
[Brief description of the drawings]
FIG. 1 is a sectional view for explaining an example of an initial step of a tunnel section widening method according to the present invention.
FIG. 2 is a sectional view for explaining a step subsequent to the step shown in FIG. 1;
FIG. 3 is a sectional view for explaining a step subsequent to the step shown in FIG. 2;
FIG. 4 is a cross-sectional view for explaining a state where the main line tunnel lining has been constructed by the process shown in FIG. 3;
FIG. 5 is a cross-sectional view for explaining a waterproofing process performed in the situation shown in FIG. 4;
FIG. 6 is a cross-sectional view for explaining a completed state of the main line tunnel and the widening tunnel constructed by the method of the present invention.
FIG. 7 is a sectional view for explaining an actual example in which a widened portion is required in a partial section of a tunnel.
FIG. 8 is a sectional view taken along the line AA shown in FIG. 7;
FIG. 9 is a perspective view for explaining a conventional tunnel section widening method.
[Explanation of symbols]
1 Main Line Tunnel 2 Widening Tunnel 11 Widening Tunnel Lining 11A Upper Floor Slab 11B Lower Floor Slab 12 Retaining Wall 13 Temporary Wall 14 Slide Hood 15 Shield Machine Drilling Line 16 Main Line Tunnel Lining 17 Backfill Injection Material 18 Waterproofing Section

Claims (4)

In the tunnel cross-section widening method of installing a widening tunnel in a section of the main line tunnel,
At the position where the widening tunnel is to be constructed, the opening surface of the main line tunnel lining to be built in contact with this widening tunnel is arranged toward the virtual construction position, and the widening tunnel lining with a substantially U-shaped cross section is constructed A tunnel cross-section widening method comprising constructing a main line tunnel lining by a shield method in contact with the top and bottom floor slabs of the widening tunnel lining. 2. The tunnel section widening method according to claim 1, wherein the widening tunnel lining is constructed by an open-cutting method, and a temporary wall closing the opening surface of the U-shaped cross section is temporarily provided inside the opening surface, and the upper floor slab and the lower floor slab are combined. A tunnel cross-section widening method characterized by having a role as a supporting material to be joined and constructing a main line tunnel lining by burying earth and sand outside the temporary wall. 2. The tunnel cross-section widening method according to claim 1, wherein the widening tunnel lining is constructed by a shield method, and a temporary wall for closing the opening surface from the opening surface to the inside is constructed together with the construction of the widening tunnel lining. A tunnel cross-section widening method characterized by having a role of a supporting material for joining the plates and constructing a main line tunnel lining by burying earth and sand outside the temporary wall. In any of the tunnel cross-section widening methods according to claims 1, 2, and 3, the construction for constructing the main line tunnel lining is performed at both ends of an upper floor slab and a lower floor slab constituting the widening tunnel lining. A tunnel cross-section widening method characterized by being constructed by a shield method that partially covers the cutting area.

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