JP5176514B2 - Segment, shield tunnel construction method, and shield tunnel - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a segment that can be constructed without using a backfilling material, a shield tunnel construction method using the same, and a shield tunnel thereof, in constructing a shield tunnel that does not block groundwater flow.

Conventionally, in constructing a shield tunnel, there has been proposed a technique for avoiding this when a groundwater flow flowing through the ground is blocked by the shield tunnel.
For example, in Patent Document 1, a tail void, which is a gap between a segment back surface and a natural ground, is filled with a water-permeable backfill material such as a porous material, thereby bypassing groundwater around the tunnel. A shield tunnel that forms a flow path is disclosed.
JP-A-10-280888

  However, in the shield tunnel disclosed in Patent Document 1, it is necessary to procure a backfill material having water permeability, which is troublesome and increases the material cost.

  The present invention has been made in view of the above points, a segment capable of constructing a shield tunnel without blocking a groundwater flow without using a backfill material, a shield tunnel construction method using the same, and The purpose is to provide the shield tunnel.

To achieve the above object, the present invention provides a segment used in the construction of the of shielded tunnel,
A segment body,
A bag body provided on the back surface of the segment main body and inflated by being filled with a filler;
A water permeable portion provided on the back surface of the bag body and having water permeability ;
Wherein the back surface of the permeable portion, prior to lysis does not pass the tail sealing soluble sheet is characterized that you have provided (first invention).

According to the segment of the present invention, after assembling the segment ring with this segment, the bag body is filled with a filler, whereby the bag body expands and the water permeable portion is pressed against the ground, and the reaction force causes the ground to enter the ground. Fixed to. Here, since the water-permeable part that contacts the natural ground is also constructed in a ring shape, the groundwater flow flows in from a part of the ring-shaped water-permeable part and circulates around the ring-shaped water-permeable part. Since it flows out from the other part, the shield segment which does not interrupt | block a groundwater flow can be constructed.
In addition, when installing a segment in a tunnel that has been excavated, a tail brush is provided between the back of the segment and the inner surface of the shielded excavator to prevent water from entering the tunnel from the tail void. At the same time, a tail seal (high viscosity grease) is supplied to the portion, but the tail seal may enter the gap of the water permeable portion and reduce the flow of water in the water permeable portion.
On the other hand, according to the segment of the present invention, since the water-soluble sheet is provided on the back surface of the water permeable portion, the tail seal does not enter the water permeable portion when installing the segment. After the installation, when the groundwater comes into contact with the water-soluble sheet, the water-soluble sheet is dissolved and washed away together with the tail seal by the groundwater, so that the water permeability of the water-permeable portion is not impaired.

According to a second invention, in the first invention, the filling material has fluidity when filled into the bag body, and after filling into the bag body, it hardens over time and has a predetermined compressive strength. It becomes the hardened | cured material which has this, It is characterized by the above-mentioned.
According to the segment of the present invention, since the filler becomes a cured body having a predetermined compressive strength, the shield segment can be reliably fixed at a predetermined position while the bag body is pressed against the ground.

A third invention is characterized in that, in the first or second invention, the bag body is made of a material that does not leak at least the water filling portion side of the filling material filled therein.
According to the segment of the present invention, since the filler filled in the bag body does not leak into the water permeable portion, the filler penetrates into the gap of the water permeable portion and seals the gap, thereby reducing the water permeability. There is nothing.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the invention, the bag body has an inner surface between the segment main body portion and the water permeable portion before the filler is filled in the bag body. It is bonded so that the space is fixed, and when the filler is filled, the bonding portion is released by the filling pressure.
According to the segment of the present invention, when the segment is installed in the excavated tunnel, the water permeable portion is fixed to the segment main body portion without filling the bag body with the filler. The water permeable part can be appropriately installed on the ground surface.

  According to a sixth invention, in any one of the first to fifth inventions, the water-permeable portion is configured of hetimalon, porous concrete, or a water-permeable bag filled with sand or gravel.

  7th invention is the method of constructing the shield tunnel which does not interrupt | block a groundwater flow, Comprising: The bag which is provided in the back surface of a segment main-body part and the said segment main-body part, and expands by being filled with a filler A plurality of segments comprising a body and a water permeable portion provided on the back surface of the bag body and having water permeability, and segmenting at a position crossing at least groundwater flowing through the ground in the construction path of the shield tunnel A step of pressing the water permeable portion against the ground by filling the bag body with the filler, and a step of curing the filler filled in the bag body. And

A fifth invention is characterized in that, in any one of the first to fourth inventions, the water-permeable portion is composed of hetimalon, porous concrete, or a water-permeable bag filled with sand or gravel.

6th invention is the method of constructing the shield tunnel which does not interrupt | block a groundwater flow, Comprising: The bag which is provided in the back surface of a segment main-body part and the said segment main-body part, and expand | swells by being filled with a filler A plurality of segments comprising a body and a water permeable portion provided on the back surface of the bag body and having water permeability, and segmenting at a position crossing at least groundwater flowing through the ground in the construction path of the shield tunnel A step of pressing the water permeable portion against the ground by filling the bag body with the filler, and a step of curing the filler filled in the bag body. And

The seventh invention is a shield tunnel that does not block the groundwater flow, and is provided on the back surface of the segment main body portion and the segment main body portion, and the bag body that expands by being filled with the filler, Assembling the segment ring at a position crossing at least the groundwater flowing in the ground, among the construction routes of the shield tunnel, using a plurality of segments comprising a water permeable portion provided on the back surface of the bag body and having water permeability, By filling the bag body with the filler, the water-permeable portion is pressed against the ground, and the bag is filled with the filler, which is constructed.

  As shown in FIGS. 1A and 1B, the segment 100 includes a segment main body 110, a bag body 120 provided on the back surface of the segment main body 110, and a water permeable portion 130 provided on the back surface of the bag body 120. Consists of In addition, the segment 100 is manufactured as a piece obtained by dividing a ring-shaped structure serving as a covering body into several pieces in the same manner as a normal segment, and can be used in appropriate combination with a normal segment.

  The segment main body 110 is a portion that supports earth pressure received from the natural ground in order to prevent the natural ground from collapsing. As the segment main body 110, reinforced concrete, steel, ductile, or a combination of these can be used in the same manner as a commonly used segment material.

  A through hole 112 is formed in the segment body 110 from the space in the tunnel to the ground. The normal segment is also provided with such a through hole in order to fill the tail void, which is a gap between the segment back surface and the ground, with the backfill material. When using as, this through-hole is good also as the through-hole 112 of the segment 100 of this embodiment.

  The through-hole 112 is provided with a check valve 114 so that the filler once filled from the tunnel inner space side does not flow backward to the tunnel inner space side.

  The bag body 120 is made of an impermeable material that does not leak the filling material filled therein, and is made of, for example, a vinyl chloride sheet. The bag body 120 includes an opening 120a that allows the inside of the bag 120 to communicate with the through hole 112. When the filler is filled from the hole on the space side in the tunnel of the through hole 112, the opening from the through hole 112 is opened. A filler is introduced into the bag body 120 via 120a. Note that the material of the bag body 120 has sufficient strength that it does not rupture when the filler is filled with a filling pressure that fixes the segment 100 assembled in a ring shape.

  For example, the bag body 120 is formed in a flat shape so as to be provided along the back surface of the segment main body 110, and when the inside is filled with a filler, the bag body 120 expands to increase its thickness.

  In addition, in the state where the bag body 120 is not filled with the filler, the facing surface inside the bag body 120 is adhesive or Velcro (registered trademark) so that the water permeable portion 130 is fixed to the segment main body portion 110. The water-permeable part 130 can be appropriately installed on the natural ground surface. Then, when the bag body 120 is filled with the filler, the adhesive portion is released by the filling pressure, and the bag body 120 expands.

  As a filler, what mixed the bentonite, water glass, etc. with the cement normally used as a backfilling material of a shield tunnel, for example can be used. The filling material is not limited to this, and has fluidity when filled into the bag body 120, and has a compressive strength necessary for fixing the segment 100 by hardening to the bag body 120 with the passage of time after filling. Any material can be used as long as it becomes a cured body (for example, only cement may be used).

  The water permeable portion 130 is made of a material having a predetermined compressive strength and a water permeability coefficient. Specifically, the water permeable part 130 introduces groundwater that circulates to the ground pressed in that state and rigidity enough to maintain a predetermined thickness even when a compressive load accompanying the expansion of the bag body 120 acts. For example, Hetimaron (registered trademark), porous concrete, or a water-permeable bag filled with sand or gravel can be used. Hetimaron is a three-dimensional reticulated molded product made of plastic manufactured by Shinko Nylon. The material is not limited to these, and any material may be used as long as it has a predetermined water permeability and a predetermined strength, such as pumice, lightweight aggregate, pearlite, and hard sponge.

  In addition, a water-soluble sheet 132 made of, for example, a water-soluble polymer or hydrolytic paper is provided on the back surface of the water-permeable portion 130. When installing the segment 100 in the excavated tunnel, a tail brush is provided between the back surface of the segment 100 and the inner surface of the shielded excavator to prevent groundwater from entering the tunnel from the tail void. A tail seal (high-viscosity grease) is supplied to the portion, but by providing the water-soluble sheet 132, the tail seal can be prevented from entering the water-permeable portion 130. That is, when the tail seal enters the gap of the water permeable portion 130, the water permeability of the water permeable portion 130 is reduced, but the water-soluble sheet 132 can prevent such a water permeability reduction. In addition, after the segment 100 is installed, the water-soluble sheet 132 is dissolved by contact with the groundwater and is washed away by the groundwater together with the tail seal. As a result, the groundwater can enter the permeable portion 130 and be distributed. become.

  The thickness of the segment 100 described above is the sum of the thickness of the segment main body 110, the thickness of the bag body 120 filled with the filler, and the thickness of the water permeable portion 130. It is necessary to make it small by the thickness of the bag body 120 and the water permeable part 130 with respect to a general segment. In this case, it is preferable to take measures so as not to reduce the strength of the segment 100 by increasing the amount of reinforcing bars provided in the segment main body 110 or using high-strength concrete.

Next, the installation method of the segment 100 in the construction of the shield tunnel using the segment 100 will be described.
FIG. 2 is a flow showing a method for installing the segment 100. FIG. 2 shows an area near the wall surface of the tunnel excavated by the shield excavator.
As shown in FIG. 2, the installation method of the segment 100 includes a segment ring assembly step S10, a shield excavator forward movement step S20, a filler filling step S30 for filling the bag body 120 with a filler, This includes a curing step S40 for curing the filler filled in the bag body 120.

  First, in the segment ring assembling step S10, the segment ring is assembled by using the segment 100 at a position crossing at least the ground water flowing through the ground in the shield tunnel construction route. The method of assembling the segment ring is the same as the assembling of a normal segment, that is, the segment 100 is transported to the tunnel tip by a segment carriage or the like, and an erector or Assemble it like a ring by human power.

For example, assembling is performed sequentially symmetrically from the lower part of the ring, and finally a key segment is inserted into the longest part. When assembling these segments 100, the segments 100 (or ordinary segments) adjacent in the tunnel axis direction are fixed with bolts or pins, etc., and rubber or synthetic resin for water-stopping is used for the joints. The packing is provided.
After assembling the segment ring in this manner, the shield excavator forward movement step S20 is then performed.

  A tail brush 52 is provided on the inner peripheral surface of the skin plate 50 of the shield excavator so as to follow the rearmost surface of the segment 100, and a tail seal 53, which is a high-viscosity grease, is supplied. The inner peripheral surface of the excavator and the rearmost surface of the segment 100 are sealed to prevent the underground water and earth and sand on the natural ground 60 side from entering the tunnel space. As described above, since the water-soluble sheet 132 is provided on the surface of the water permeable portion 130 which is the rearmost surface of the segment 100, the tail seal 53 does not enter the water permeable portion 130.

  When the shield excavator moves forward, a gap (tail void 54) is generated between the natural ground 60 and the water permeable portion 130 located on the rearmost surface of the segment.

  In the filler filling step S30, the bag body 120 is inflated by filling the filler 140 from the through space 112 of the segment 100 from the inner space side of the tunnel, and the water permeable portion 130 is brought into close contact with the natural ground 60 so that the tail void 54 is eliminated. Let

  Then, in the curing step S40, the installation of the segment 100 is completed by curing the filler 140 filled in the bag body 120 for a predetermined time.

  According to the segment 100 according to the present embodiment described above, the segment main body 110, the bag body 120 provided on the back surface of the segment main body section 110 and inflated by being filled with the filler 140, and the bag body 120 By comprising a water permeable portion 130 provided on the back surface and having water permeability, by assembling the segment ring with this segment 100 and then filling the bag body 120 with the filler 140, the bag body 120 expands and water permeability The portion 130 is pressed against the natural ground and fixed to the tunnel wall surface by the reaction force. Further, since the filler 140 becomes a cured body having a predetermined compressive strength, the segment 100 can be reliably fixed at a predetermined position while the bag body 120 is pressed against the ground.

FIG. 3 is a cross-sectional view of the segment ring 10 fixed to the tunnel wall surface and orthogonal to the tunnel axis.
In addition, as shown in FIG. 3, the permeable portion 130 that contacts the natural ground is also formed in a ring shape, so that the groundwater flow flows from one side of the ring-shaped permeable portion 130, Since it goes around and flows out from the other side of the ring-shaped water-permeable portion 130, the shield segment 100 that does not block the groundwater flow can be constructed.

  In addition, a normal backfill material is mixed with bentonite or water glass in cement to provide water shielding, and is filled in a tail void 54, which is a gap between the segment and the ground 60, so that a joint between the segments can be obtained. However, the shield tunnel disclosed in Patent Document 1 uses a water-permeable backfill material, so the ground 60 is connected between the segments. There is a risk of groundwater entering the tunnel space through joints.

  On the other hand, in the segment 100 according to the present embodiment, since the bag body 120 made of a material having impermeability is provided between the water permeable portion 130 and the segment main body portion 110, the groundwater is tunneled from the natural ground 60. It is possible to prevent intrusion into the inner space. Furthermore, the bag body 120 is filled with a normal backfilling material having a water-blocking property, so that even if the bag body 120 is damaged, the ground water is prevented from entering the tunnel space.

  Note that the bag body 120 of the present embodiment is made of a material having an impermeability that does not leak the filler 140 filled in the interior to the outside. However, the present invention is not limited thereto, and the filler 140 filled in the interior is not limited to this. Any material or structure that expands without leaking to at least the water permeable portion 130 side may be used. In other words, it is sufficient that the filler 140 is leached into the water permeable portion 130 so that the filler 140 is cured in the water permeable portion 130 and the water permeability of the water permeable portion 130 is not impaired.

Further, the embodiment according to the present invention may be as follows.
FIG. 4 shows a schematic configuration of a segment 200 according to the second embodiment. FIG. 4 (a) is a perspective view, and FIG. 4 (b) is a sectional view taken along line BB of FIG. 4 (a). .
As shown in FIG. 4, the segment 200 according to the second embodiment has a cross-sectional structure provided on the segment main body 210 and the back surface of the segment main body 210, similarly to the segment 100 according to the first embodiment. The bag body 220 and the water permeable portion 230 provided on the back surface of the bag body 220 are made of steel and plate-like ribs 214 projecting in the direction of natural ground and segmented in a lattice shape. The bag body 220 and the water permeable portion 230 are housed in the enclosed areas so that the bag body 220 and the water permeable portion 230 do not protrude from the tips of the ribs 214. It is provided to be. A water-soluble sheet 132 is provided on the back surface of each water permeable portion 230 provided in a region surrounded by the ribs 214, and each bag body 220 is also provided with a through hole 212 communicating with the inside thereof. ing.

FIG. 5 is a diagram illustrating an operation in the forward movement process S20 of the shield excavator of the shield tunnel in which the segment 200 according to the second embodiment is installed.
As shown in FIG. 5, by adopting such a configuration of the segment 200, when the shield excavator described in FIG. 2 moves forward, the ribs 214 are formed on the inner periphery of the skin plate 50 of the shield excavator. Since the tip of the tail brush 52 provided on the surface is bent so as not to reach the water-soluble sheet 132, it is possible to suppress the tip of the tail brush 52 from scratching and damaging the water-soluble sheet 132. Thereby, it is possible to prevent the tail seal 53 from entering from the damaged water-soluble sheet 132 and lowering the water permeability of the water permeable portion 230.
For the water permeable portion 230 of the segment 200, for example, a gravel filled with a water permeable bag is used.

FIG. 6 is a cross-sectional view when the filling material 140 is filled in the bag body 220 of the segment 200 shown in FIG.
As shown in FIG. 6, when the bag body 220 is filled with the filler 140 and the bag body 220 expands, the water permeable portion 230 is pressed against the natural ground 60 by being discharged from the enclosed rib 214. At the same time, it expands in the horizontal direction. Thereby, the segment 200 is fixed to the natural ground 60, and the shield tunnel which has a water-permeable area | region in an outer periphery will be constructed | assembled, and interruption | blocking of a groundwater flow is avoided.

The schematic structure of the segment 100 which concerns on 1st embodiment is shown, The figure (a) is a perspective view, The figure (b) is AA sectional drawing of the figure (a). It is a flow which shows the installation method of the segment 100. FIG. It is sectional drawing orthogonal to a tunnel axis | shaft of the segment ring 10 of the state fixed to the tunnel wall surface. The schematic structure of the segment 200 which concerns on 2nd embodiment is shown, The figure (a) is a perspective view, The figure (b) is BB sectional drawing of the figure (a). It is a figure which shows operation | movement in the forward movement process S20 of the shield type excavator of the shield tunnel in which the segment 200 which concerns on 2nd embodiment was installed. It is sectional drawing when the filler 140 is filled in the bag body 220 of the segment 200 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Segment ring 50 Skin plate 52 Tail brush 53 Tail seal 54 Tail void 60 Ground 100,200 Segment 110,210 Segment main body part 112,212 Through hole 114 Check valve 120,220 Bag body 130,230 Water permeable part
132 Water-soluble sheet 140 Filler 214 Rib S10 Assembly process S20 Forward movement process S30 Filler filling process S40 Curing process

Claims (7)

A segment used to build a shield tunnel,
A segment body,
A bag body provided on the back surface of the segment main body and inflated by being filled with a filler;
A water permeable portion provided on the back surface of the bag body and having water permeability ;
Wherein the back surface of the permeable portion, characterized that you have a water-soluble sheet is provided which does not pass through the tail seal prior to lysis segment.   The filler has fluidity when filled into the bag body, and after being filled into the bag body, the filler is cured with the passage of time to become a cured body having a predetermined compressive strength. The segment of claim 1.   The segment according to claim 1, wherein the bag body is made of a material that does not allow the filler filled therein to leak at least to the water-permeable portion side. The bag body is bonded so that the inner surface of the bag body is fixed between the segment main body portion and the water permeable portion before the bag body is filled with the filler.
The segment according to any one of claims 1 to 3, wherein when the filler is filled, the adhesive portion is released by the filling pressure. The segment according to any one of claims 1 to 4 , wherein the water permeable portion is composed of hetimalon, porous concrete, or a water permeable bag filled with sand or gravel. A method of constructing a shield tunnel that does not block the groundwater flow,
A segment comprising: a segment body part; a bag body provided on the back surface of the segment body part and inflated by being filled with a filler; and a water permeable part provided on the back surface of the bag body and having water permeability. Using a plurality of steps, assembling a segment ring at a position crossing at least groundwater circulating in the ground, among the construction routes of the shield tunnel;
A step of pressing the water permeable portion against the ground by filling the bag with the filler;
A step of curing the filler filled in the bag, and a method for constructing a shield tunnel. It is a shield tunnel that does not block the groundwater flow,
A segment comprising: a segment body part; a bag body provided on the back surface of the segment body part and inflated by being filled with a filler; and a water permeable part provided on the back surface of the bag body and having water permeability. Using multiple, assemble a segment ring at a position that crosses at least the groundwater that circulates in the ground, among the construction routes of the shield tunnel,
By filling the bag body with the filler, the water permeable portion is pressed against the ground,
A shield tunnel constructed by curing the filler filled in the bag.

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