JP3918648B2 - Tunnel impermeable structure and steel box segment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water-blocking lining structure for a tunnel and a steel box-shaped segment that completes water-tightness and lining of a water-proof plug by establishing water-blocking in the tunnel.
[0002]
[Prior art]
Key points of tunnels to prevent leakage of harmful substances, such as tunnel construction in specific areas and underground facilities for radioactive waste, which prevent vegetation changes from occurring due to the water level of the ground surface being lowered by tunnel spring water In underground tunnel construction where it is necessary to provide a water-impervious plug, water-tightness that ensures water-tightness is required.
[0003]
However, in conventional tunnel construction, cement-based lining materials are used for lining and shielding. Will be required.
[0004]
In other words, lining with perfect water-blocking performance is not practical for general tunnels, so the tunnel lining material is cement-based, and in the case of the mountain tunnel method, it is laid with cast-in-place concrete lining. In the case of the shield method, concrete segments are often used. However, in the former case, it is impossible to construct a complete water barrier lining because it is impossible to make concrete cracks zero. In the latter case, it is possible to ensure water-stopping by inserting rubber or other sealing material between the joints of the segments, but since the secondary lining concrete cannot be cracked to zero, a complete water-blocking cover is required. It is difficult to build a craft.
[0005]
In addition, as shown in the outline of the underground buried tunnel in the underground facility for radioactive waste, as shown in Fig. 3, the tunnel 10 is constructed with a waterproof plug 11 that satisfies the following conditions. Therefore, harmful nuclides that leak from the waste into the groundwater in a minute amount are prevented from leaking into the living area on the surface of the earth using the tunnel 10 as a waterway.
[0006]
However, the water shielding plug 11 needs to solve the following problems.
(1) Water shielding performance deteriorates due to long-term alteration and dissolution in groundwater.
{Circle around (2)} In order to generate a permeability increase area in the loose area around the tunnel, it is necessary to install a widening plug having a larger cross section than the standard cross section.
(3) The support material and lining structure for stably maintaining the tunnel space with a large cross section will deteriorate the water shielding performance over a long period of time.
(4) The permeability increase area in the loose area around the tunnel cannot be suppressed.
[0007]
For this reason, the water-insulating plug 11 formed in the plug construction section and provided with the manhole 12 is made of high-quality natural clay, which is a material that is easy to ensure water-proofing without deterioration over a long period of time. One bentonite is used. The compressed bentonite 13 is formed into a shell structure by assembling segments with a steel partition frame 14 and tie rod bolts 15 on both sides thereof, and is compressed by a tunnel support structure 16 configured as a shell structure. .
[0008]
And while construction of the water-impervious plug 11, construction is promoted while utilizing the manhole 12. After the construction is completed, the manhole 12 is sealed with high-quality natural clay bentonite.
[0009]
However, since the concrete lining structure 17 is installed before and after the water shielding plug 11 and the cement lining material 17 is used for the tunnel lining structure 17, cement is added to the groundwater after a long period of time. There is a concern that the components may elute and chemically change the bentonite of the water shielding plug 11.
[0010]
Bentonite is high quality during the period when Na ions are prevalent in exchangeable cations, whereas when Ca ions predominate, the performance deteriorates, so Ca ions in the cement component are the cause of adverse effects. As a result, the water impermeability in the tunnel 10 is not reliable.
[0011]
Therefore, the tunnel construction in a specific area or the underground buried tunnel construction where a water shielding plug is installed in the underground facility of radioactive waste requires water shielding to ensure water tightness, but it completely solves the above problems The current situation is that the water barrier lining structure of the tunnel has not yet been provided.
[0012]
[Problems to be solved by the invention]
The present invention proposes an improved structure in view of the above situation, and establishes a water-blocking lining structure for a tunnel that completes water-tightness and lining of a water-blocking plug by establishing water-blocking in the tunnel. We provide steel box segments.
[0013]
[Means for Solving the Problems]
The water-blocking lining structure of the tunnel according to the present invention comprises a lining structure composed of segments made of a high-density clay-based soil material, and the segments are formed in a box shape opened to the bedrock side to form a high-density clay-based interior. Filled with soil material. Then, the tunnel lining structure is made into a shell structure formed by assembling segments, or a water-impervious plug in a radioactive waste underground facility, and the shell structure formed by assembling segments is backed up with bentonite and slurry. It has a feature.
[0014]
Further, the steel box-shaped segment according to the present invention is a segment used for the above-mentioned tunnel impermeable structure of a tunnel, and is a steel box formed by opening the bedrock side and a high density filled in the steel box. It consists of clay-based soil materials.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The water-impervious lining structure of the tunnel according to the present invention is configured by arranging a segment filled with a high-density clay-based soil material inside a steel box with an open bedrock side. By constructing a steel box formed by opening the bedrock side and a high-density clay-based soil material filled in the steel box, water shielding in the tunnel is established.
[0016]
DESCRIPTION OF EMBODIMENTS Embodiments of a water-blocking lining structure for a tunnel and a steel box-shaped segment according to the present invention will be described below in detail with reference to the drawings.
[0017]
FIG. 1 shows a perspective view of a water barrier lining structure of a tunnel according to the present invention and an embodiment of a steel box segment partially taken out. The impermeable structure 1 according to the present invention is not specified at the front and rear joining positions of a plurality of steel box-shaped segments 2 to be described later. Constructed in a cylindrical or shell structure to ensure watertightness.
[0018]
The steel box-shaped segment 2 is formed in a steel box 4 having a predetermined shape according to the cylindrical shape of the lining or the shell structure, with the outer side 3 being opened by processing the steel plate. The steel box 4 is configured as a single steel box-shaped segment 2 by being filled with bentonite 5 which is a high-density clay-based soil material up to the outer surface of the steel box 4.
[0019]
FIG. 2 is a state diagram for explaining the secular change state of the water-blocking lining structure according to the present invention.
[0020]
In the figure, FIG. 2A shows a state in which the steel box-shaped segment 2 is arranged on the rock surface 6, and a slight gap 7 is provided between the steel box-shaped segment 2 and the rock surface 6. Bentonite is present while leaving. It is sufficient that the gap 7 formed between the steel box-shaped segment 2 and the rock surface 6 is sufficient to perform construction workability smoothly, and is not so large as to be exaggerated in the drawing. In particular, when the tunnel lining structure is a shell structure formed by assembling the steel box segments 2, it is also effective to back up in accordance with a general construction method.
[0021]
As the backing material in this case, a bentonite-based slurry material such as a mixed material of bentonite and water or a mixed material of bentonite, ethanol and water is suitable. The gap is formed in a sealed state by filling between the rock surface and the rock surface 6.
[0022]
FIG. 2 (b) shows the state where the impermeable lining structure 1 has been properly aged, and when the groundwater from the rock surface 6 has entered the tunnel, it becomes water droplets 8 and becomes a steel box. When the groundwater is dropped into the bentonite 5 filled in the shape segment 2 and the groundwater is absorbed and absorbed into the bentonite, or the gap is filled with the bentonite-based slurry material, the groundwater is also absorbed and absorbed into the bentonite-based slurry material. become. As a result, the bentonite 5 and bentonite-based slurry material of the steel box-shaped segment 2 absorb water and expand, thereby sealing the water space between the steel box-shaped segment 2 and the rock surface 6. Further, since the expansion of bentonite 5 also seals the joints between the steel box-shaped segments 2, the water shielding performance of the lining structure 1 is surely exhibited, and the shell structure of the segments is backed up. In some cases, these functions will be further increased.
[0023]
Bentonite is a material that has existed stably for more than several hundred thousand years in the natural underground environment. When there is no material that produces a chemical impact such as cement in the vicinity, long-term soundness is maintained. It can be expected and does not exhibit mechanical strength by itself, but it can fully exhibit desired strength by filling the steel box-shaped segment 2 as in the present invention. The box-shaped segment 2 functions as a supporting structure material until the tunnel is backfilled.
[0024]
Furthermore, the swelling of bentonite is achieved by filling the water space between the steel box-shaped segment 2 and the rock surface 6 so that the hydraulic conductivity is as small as 1E-8 m / s to 1E-13 m / s. The water path of groundwater is blocked, and at the same time, there is no generation of water-permeable pathways due to cracks like cement-based materials.
[0025]
The tunnel impermeable structure of the tunnel and the steel box-shaped segment according to the present invention do not use cement-based materials at all. Therefore, the elements that deteriorate the bentonite are removed, and the steel material is used for a long time. Even when the volume is reduced to zero due to corrosion, the bentonite that swells the space where the steel material has disappeared seals this and prevents the generation of water, thus ensuring the establishment of tunnel water shielding. .
[0026]
As described above, the present invention has been described in detail on the basis of the embodiment. However, the water-blocking lining structure and the steel box-shaped segment of the tunnel according to the present invention are not limited to the above-described embodiment. It goes without saying that various modifications can be made without departing from the spirit of the present invention with respect to the specific structure and material of the form, segments and the like.
[0027]
【The invention's effect】
The water-blocking lining structure of the tunnel according to the present invention comprises a lining structure with segments made of high-density clay-based soil material, and the segments are formed in a box shape opened to the rock mass side to form a high-density clay-based inside Filled with soil material. Then, the tunnel lining structure should be a shell structure formed by assembling the segments, or a water-impervious plug for radioactive waste underground facilities, and the shell structure formed by assembling the segments should be backed with bentonite and slurry. Because it is a feature, it has the effect of perfecting the water tightness and lining of the water shielding plug by establishing water shielding in the tunnel.
[0028]
Further, the steel box-shaped segment according to the present invention is a segment used for the above-mentioned tunnel impermeable structure of a tunnel, and is a steel box formed by opening the bedrock side and a high density filled in the steel box. Since it is composed of clay-based soil materials, it has the effect of providing effective segments to complete the water tightness and lining of the water barrier plugs by establishing the water barrier in the tunnel.
[Brief description of the drawings]
FIG. 1 is a diagram of an embodiment of a water-blocking lining structure of a tunnel and a steel box-shaped segment according to the present invention. FIG. 2 is a secular change diagram of a steel box-shaped segment according to the present invention. Schematic diagram of impermeable plugs in underground facilities [Explanation of symbols]
1 Water-blocking lining structure, 2 Steel box-shaped segment, 3 Outside, 4 Steel box 5 Bentonite, 6 Rock surface, 7 Gap, 8 Water drop,
10 tunnels, 11 water blocking plugs, 12 manholes,
13 Bentonite filler, 14 Steel partition frame,
15 tie rod bolts, 16 tunnel support structure, 17 lining structure,

Claims (3)

A segment used for tunnel lining structure,
A steel box that is open only on the bedrock side and enclosed in a box shape with a steel plate, and is formed into a shape that matches the cylindrical shape or shell structure of the lining,
Bentonite that has been filled up to the outer surface of the steel box in advance;
A steel box segment characterized by comprising: A tunnel impermeable structure, characterized in that the tunnel lining structure is a structure formed by assembling the steel box-shaped segments of claim 1 . The water-impervious lining structure according to claim 2, wherein a bentonite-based slurry material is backed up between the steel box-shaped segment of claim 1 and the rock surface of the tunnel.

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