JP4453879B2 - Shield tunnel method - Google Patents

Description

  The present invention relates to a shield tunnel method constructed by assembling segments while excavating with a shield machine.

  In the civil engineering shield method, when the shield tunnel is constructed by assembling the segments while excavating with a shield machine, the shield tunnel 1 is arranged in a direction perpendicular to the flow direction of the groundwater flow 6 as shown in FIG. It may be constructed in the permeable soil layer 2.

  In order to prevent the ingress of groundwater into the tunnel, the shield tunnel 1 is made of, for example, steel that does not allow water to enter the outer shell of the segment, and a sealing material for water stoppage is provided between the segment pieces and between the segment rings. Since the water blocking structure is interposed, when the shield tunnel 1 is constructed in the permeable soil layer 2, the flow of the groundwater flow is blocked by the shield tunnel 1. In the figure, 3 indicates an impermeable soil layer.

  When the groundwater flow 6 is blocked by the shield tunnel 1, the groundwater flow 6 located downstream of the place where the shield tunnel 1 is constructed has a water level B after the tunnel construction higher than the water level A before the shield tunnel 1 construction. As a result, the well 4 or the like provided in this region causes inconveniences such as the well withering.

  On the other hand, in the groundwater flow 6 located upstream from the place where the shield tunnel 1 is constructed, the water level C after the tunnel construction is higher than the previous water level A, and as a result, the building 5 constructed in this area. Leakage and inundation occur in the basement.

  In addition, since the water level (water amount) is different between the upstream side and the downstream side of the groundwater flow 6 with respect to the shield tunnel 1, the earth pressure and the water pressure are also generated in the segment. For this reason, a high strength (high proof stress) segment is required.

  The object of the present invention is to eliminate the inconvenience of the conventional example, and when the shield tunnel is built in the permeable soil layer in the direction orthogonal to the flow direction of the groundwater flow, the groundwater level fluctuates without blocking the groundwater flow. An object of the present invention is to provide a shield tunneling method that can prevent the occurrence of such a phenomenon and does not affect the surroundings.

In order to achieve the above-mentioned object, the present invention provides a shield tunneling method constructed by assembling segments while excavating with a shield machine, and the segment outer shell is formed of a structural member having pressure resistance. The inner face plate is made of water-tight and has a sealed structure, and only the tail void part of the segment piece in the water-permeable section located in the water-permeable soil layer is filled with water-permeable backfill filler so that this segment piece is water-permeable. The tail void portion of a general segment piece that is not located in the permeable soil layer is filled with a general backfill injection material, and a backfill filler material that is injected into the tail void portion of the segment piece in the water permeable section is provided. By filling it as a material with water permeability such as porous material, high void material, gap creating material, foaming material, etc. Shield tunnel forms a water-permeable means through which ground water along the segment on the outside of the segments so as not to block the groundwater flow, and between the segment piece which imparts permeability means permeability segment and general segment piece A flexible bag-like body made of materials such as rubber, vinyl, etc. is built in, and after assembly, an injecting material is injected into the bag-like body using air, water, mortar, or other fluid objects. The gist is to interpose a special segment piece for preventing intrusion, which causes the swell to stick to the ground.

  According to the first aspect of the present invention, the backfilling material to be applied to the tail void portion is made of a material having water permeability, so that the groundwater is surrounded by the outer periphery of the segment where the backfilling material is filled. Since it passes, the groundwater can be easily permeated without processing the segment.

  As described above, the shield tunneling method of the present invention is a water permeable method that does not block the groundwater flow in the shield tunnel even when the shield tunnel is built in the permeable soil layer in a direction orthogonal to the flow direction of the groundwater flow. Since the means is provided, the water flow allows the groundwater flow to flow in the same direction as before the tunnel construction through the tunnel without being blocked by the shield tunnel. Therefore, since there is no change in the water level upstream and downstream of the groundwater flow after the tunnel is built across the shield tunnel, there is no uneven soil pressure or uneven pressure on the shield cross section, and it is a lightweight and inexpensive segment. Tunnel lining can be performed. In addition, tunnels can be constructed at free positions without being affected by groundwater flow.

  Then, by making the backfilling filler material for the tail void part of a material having water permeability, groundwater passes through the outer periphery of the segment where the backfilling filler is filled. Without applying it, you can easily permeate the groundwater.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the shield tunnel method of the present invention. In the shield tunnel method constructed by assembling segments while excavating with a shield machine, the outer shell of the segment is formed of a structural member having pressure resistance. Of these structural members, the face plate inside the mine is formed with a water-tight structure to form a sealed structure, and the ground water passes through the tail void portion 27 formed between the outer surface of the segment piece 7 and the ground 20 as a water-permeable means. The backfilling material 28 to be injected into the tail void portion 27 is made of a material having water permeability as possible.

  Examples of the material of the backfill filler 28 include a porous material, a high void material, a gap creating material, and a foamable material. The porous material is a material with internal voids in which the filler itself has water permeability, for example, a water-permeable material such as pumice, lightweight aggregate, pearlite, hard sponge, etc., and the high void material is a filler. It is a material having a large inter-particle void, such as sand, gravel, beads, pearlite, or a material obtained by processing a polymer material into a square shape.

  The gap creating material has no or few voids during the filling operation, but generates sufficient voids for water permeability when filling is completed. For example, high-concentration salt water, polymer material, gel material, shaving cream Is used as a fluidizing material, and after filling in the tail void part 27, a void is created by agglomerating and solidifying or defoaming with an antifoaming agent, a solidifying material, a flocculant, water, etc. is there.

  The foamable material is not foamed when the tail void portion 27 is filled, but foams after filling to become a porous material and has a water permeability function.

  Further, the backfill filler 28 is not limited to a single material as described above, and the filler may be replaced. For example, the backfill filler 28 itself does not solidify, for example, a gel-like material, As a shaving cream-like material, this is temporarily filled and replaced later with a material having water permeability such as a porous material.

  As shown in FIG. 2, this water-permeable backfilling filler 28 is also filled only in the tail void part 27 of the segment piece 7 in the water-permeable section located in the water-permeable soil layer 2 to give water permeability to the segment piece 7 The tail void portion 27 of the general segment piece 29 that is not located in the permeable soil layer 2 is filled with a general backfilling injection material 30.

  In this case, when the backfilling injection material 30 having no general water permeability enters the tail void portion 27 of the water permeable section, the water permeability of the water permeable section is impaired. Therefore, a special segment piece 31 for preventing intrusion is interposed between the segment piece 7 having water permeability in the water-permeable section and the general segment piece 29.

  The segment piece 31 incorporates a flexible bag-like body 32 made of a material such as rubber or vinyl. After assembly, the bag-like body 32 is filled with an injection material 33 made of a fluid substance such as air, water, or mortar. Is injected to inflate the bag-like body 32, and this is brought into close contact with the natural ground 20 side.

  Due to the close contact of the bag-like body 32 with the natural ground 20 side, the gap between the segment piece 7 having water permeability and the general segment piece 29 is sealed, and the backfilling injection material 30 having no general water permeability is formed in the water-permeable section. Intrusion into the tail void portion 27 is prevented. Thereby, the groundwater flow 6 of the permeable soil layer 2 flows through the backfill filler 28 having water permeability in the tail void portion 27 and flows along the peripheral surface of the segment piece 7, and is prevented from flowing from upstream to downstream. There is nothing.

It is a vertical front view which shows the construction state of one Embodiment of the shield tunnel construction method of this invention. It is a vertical side view of the principal part which shows the construction state of one Embodiment of the shield tunnel construction method of this invention. It is explanatory drawing of the shield tunnel built in a permeable earth layer.

DESCRIPTION OF SYMBOLS 1 ... Shield tunnel 2 ... Permeable soil layer 3 ... Impervious soil layer 4 ... Well 5 ... Building 6 ... Groundwater flow 7 ... Segment piece 20 ... Ground
24… Skin plate
25 ... Tail seal 26 ... Water shielding plate
27 ... Tail void part 28 ... Backfill filler
29… Segment piece 30… Backfill injection material
31… Segment piece 32… Bag
33. Injection material

Claims (1)

In a shield tunnel method constructed by assembling segments while excavating with a shield machine, the segment outer shell is formed of a structural member having pressure resistance, and the face plate on the inner side of the structural member is waterproof. It is formed into a sealed structure, and a backfill filler having water permeability is filled only in the tail void portion of the segment piece of the water-permeable section located in the water-permeable soil layer to provide a water-permeable means to this segment piece. The tail void part of the general segment piece not located in the layer is filled with a general backfilling injection material, and the backfilling filler material injected into the tail void part of the segment piece in the water permeable section is made of a porous material, a high void material, Filling this with a material that has water permeability, such as a production material or foaming material, allows the shield tunnel to block the groundwater flow. Along the segment to form a permeable means through which ground water on the outside of the segments so as not to, and between the segment piece which imparts permeability means permeability segment and general segment piece, rubber, materials such as vinyl After the assembly, the bag-shaped body is inflated by injecting an injecting material with a fluid object such as air, water, mortar, etc. into the bag-shaped body. A shield tunneling method characterized by interposing a special segment piece for preventing intrusion that is closely attached to the side of the door.

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