JP5723538B2 - Cutable concrete segments and shield tunnel walls - Google Patents

Description

  The present invention generally relates to the structure of a wall of a shield tunnel excavated by a shield machine that excavates in the ground. In particular, the present invention relates to a concrete segment that can be cut by a shield machine and such a segment. It relates to the wall of the shield tunnel constructed by the segment.

  Conventionally, according to the shield method of building tunnels such as roads and railways while excavating underground with a shield machine, the excavation part formed behind the shield machine by excavating the shield machine A segment tunnel wall body is constructed by assembling and installing segments along the inner wall surface.

  The segment used for the segment tunnel wall body is required to be a safe and solid structure that can withstand the soil and water pressure load of the surrounding ground and secure the predetermined tunnel interior, and is usually made of reinforced concrete, steel, Concrete and steel composite segments are used.

  On the other hand, after a tunnel is constructed by the shield method, it is required to further construct a branch tunnel in a direction different from this tunnel.

  In the conventional technology, once the main line segment is installed in the ground with a shield, the branch segment is excavated by the open-cut method, and a ramp tunnel or a junction between the main tunnel and the lamp tunnel is newly installed in combination with the freezing method. There was a need to do.

  This method has a problem that the construction period is long and the cost is very high. Various methods have been proposed to solve this problem, but few have been practically used.

  Conventionally, in starting and reaching a shield machine, a shaft wall that can be cut by a shield machine is used as part of the shaft wall, and the shaft wall is directly cut by a bit of the shield machine (patent) Reference 1).

  Or, as shown in FIG. 15, a part of the segment wall body 100 of the existing tunnel is configured with the segment 1 that can be cut by the shield machine in advance, as shown by hatching, and the existing tunnel is excavated. In some cases, cutting is performed by a shield machine 200 different from the shield machine used to construct a T-joint of a pipeline, a branch of a road tunnel, or a junction.

  As the segment 1 that can be cut by a shield machine, for example, RC using a rope-like fiber reinforced resin reinforcing bar (FRP bar) in which a reinforcing fiber such as carbon fiber or glass fiber is impregnated with resin instead of a reinforcing bar A segment, an FRU segment in which the RC portion is replaced with FRU (Fiber Reinforcing Urethane), an unreinforced concrete segment reinforced with short fibers, and the like have been proposed (see, for example, Patent Document 2 and Patent Document 3).

JP-A-5-302490 Japanese Patent No. 275163 JP-A-4-213695

  However, when constructing a T-joint of a pipe line by a shield machine, a branch of a road tunnel, or a junction, the segment cutting section is long, so the conventional FRP rebar + concrete soil that ends with excavation of only about 1 m Unlike cutting with a retaining wall, high-speed cutting is required. Further, since the segment cutting section is long, the wear of the bit of the shield machine is severe, and it is necessary to improve the wear of the bit.

  In addition, if the ground is vibrated due to poor cutting performance during segment cutting, the work must be stopped in the worst case, so the cutting vibration level is particularly low in cutting segments with long segment excavation sections. Is required.

The present inventors have conducted many research experiments to solve the above problems,
1. By setting the ratio of the lightweight aggregate constituting the coarse aggregate in the concrete (hereinafter, the lightweight aggregate as the coarse aggregate is referred to as “lightweight coarse aggregate”) to a predetermined amount,
(1) The torque during cutting decreases rapidly.
(2) The vibration level during cutting is greatly reduced,
(3) Cutting is possible even if the digging speed of the shield machine is increased.
2. Wear of the bit is reduced by setting the ratio of the lightweight aggregate constituting the fine aggregate in the concrete (hereinafter, the lightweight aggregate as the fine aggregate is referred to as “lightweight fine aggregate”) to a predetermined amount. ,
3. When the cross-sectional area of the FRP line is not too small and not too large, the FRP line is well cut and cut into a size that does not cause a problem in uptake.
I got the knowledge.

  The present invention has been made on the basis of such novel findings by the present inventors.

  It is an object of the present invention to provide a cutable concrete segment and a shield tunnel wall which can greatly reduce torque and bit wear during cutting by a shield machine and reduce vibration. .

  Another object of the present invention is to provide a concrete segment and a shield tunnel wall that can increase the cutting speed of the shield machine.

The above objective is accomplished by a machinable concrete segment and a shield tunnel wall according to the present invention. In summary, according to the first aspect of the present invention, a part of the curved circumferential portion of the shield tunnel wall for constructing the wall of the shield tunnel excavated by the shield machine is configured. In a segment made of concrete, which can be cut by a shield machine using concrete as a base material and fiber reinforced resin reinforcement as reinforcement,
The concrete includes cement, water, and aggregate, and the water-cement ratio is 20 to 40% by weight. The aggregate includes coarse aggregate and fine aggregate. The maximum size of the coarse aggregate is 5 ~ 50 mm, the maximum size of the fine aggregate is less than 5 mm,
The coarse aggregate includes a lightweight coarse aggregate, the lightweight coarse aggregate is used in an amount of 30 to 100% by weight with respect to the entire coarse aggregate, and the fine aggregate includes a lightweight fine aggregate, A lightweight fine aggregate is used in an amount of 5 to 100% by weight based on the whole fine aggregate.
The reinforcing bar is the fiber-reinforced resin reinforcing material that is a round or rectangular rod having a cross-sectional area of 2 mm ² or more and less than 500 mm ² .
A concrete segment is provided.

According to one embodiment of the present invention, the concrete is further a resin fiber 0.01-1.0 vol% saw including the total volume of the concrete,
Whether the resin fiber is a fiber made of a thermosetting resin such as an epoxy resin or a vinyl ester resin, or a fiber made of a thermoplastic resin such as polyamide, polycarbonate, polypropylene, or PPS. Or a fiber made of a thermoplastic epoxy resin .

According to another embodiment of the present invention, the fiber-reinforced resin reinforcing material is formed by impregnating a resin into a reinforcing fiber,
The reinforcing fiber is an inorganic fiber such as carbon fiber, glass fiber or basalt fiber, or an organic fiber such as aramid, polyester, nylon or vinylon, or a hybrid in which a plurality of the fibers are mixed. Type
The resin is a thermosetting resin such as an epoxy resin or a vinyl ester resin, a thermoplastic resin such as nylon or PPS, or a thermoplastic epoxy resin.

According to the second aspect of the present invention, a shield tunnel having a wall region constructed of a concrete segment that can be cut by a shield machine using concrete as a base material and fiber reinforced resin reinforcement as reinforcement. In the wall of
A wall of a shield tunnel is provided, wherein the concrete segment is a concrete segment configured as described above.

According to one embodiment of the second aspect of the present invention, the concrete segments are connected to other segments by segment joints in the circumferential direction of the shield tunnel and the extension direction of the shield tunnel,
The joint member forming the segment joint is made of a resin, or made of a fiber reinforced resin in which a reinforced fiber is impregnated with a resin.

  According to another embodiment of the second aspect of the present invention, the segment joint is a partial side joint, a joint plate, or a bolt.

  According to another embodiment of the second aspect of the present invention, the segment joint is a fiber reinforced resin strand in which the fixing portion is made of metal or resin, and the strand is inserted through the connecting segment. Arrange and tension the strands to tightly connect between the segments.

According to another embodiment of the second aspect of the present invention, the concrete segment includes a hanging metal fitting and an inlet for suspending the concrete segment,
The hanging metal fitting and the injection port are made of a resin, or made of a fiber reinforced resin in which a reinforced fiber is impregnated with a resin.

  According to the present invention, torque and bit wear during cutting by a shield machine can be significantly reduced, vibration can be reduced, and blockage of the shield machine can be prevented. In addition, the cutting speed of the shield machine can be increased.

It is a perspective view which shows one Example of the shield tunnel wall body which concerns on this invention. It is a perspective view which shows one Example of the concrete segments which concern on this invention. FIGS. 3A and 3A are perspective views showing the internal structure of an embodiment of a concrete segment according to the present invention, and FIGS. 3A and 3B are sectional views taken in the axial direction. . FIGS. 3B and 3A are perspective views showing the internal structure of an embodiment of a concrete segment according to the present invention, and FIGS. 3B and 3B are cross-sectional views taken in the axial direction. . It is a perspective view which shows the internal structure of one Example of the concrete segments which concern on this invention. FIG. 4A is a diagram showing the relationship between the ratio of lightweight coarse aggregate and the vibration level, and FIG. 4B is a diagram showing the relationship between the ratio of lightweight fine aggregate and the amount of wear. FIG. 5A is a diagram showing a schematic configuration of a concrete segment cutting test facility, and FIG. 5B is a diagram showing a schematic configuration of a concrete segment bending test facility. One Example of the joint between pieces is shown, Fig.6 (a) is the figure seen from the end surface extended in the circumferential direction of a segment, FIG.6 (b) is a perspective view of a coupling metal fitting. FIG. 7 (a-1) and FIG. 7 (b-1) are views seen from the end surface extending in the circumferential direction of the segment, and FIG. 7 (a-2). , (B-2) is a view from the inside of the tunnel. FIG. 8 (a) is a view seen from an end face extending in the circumferential direction of the segment, and FIG. 8 (b) illustrates reinforcement of the end face of the segment. It is a figure and it is the figure seen from the end surface extended in the circumferential direction of a segment. It is an end elevation which shows the other Example of the joint between pieces, and extends in the circumferential direction of the segment seen in the axial direction of the tunnel. FIG. 10 (a-1), (b-1), and (c-1) are views showing a joint portion of a segment extending in the circumferential direction from the outside of the segment. 10 (a-2), (b-2), and (c-2) are views of the joining end surface on one side of the segment. Fig. 11 (a) is a perspective view showing a concave portion of a side mechanism, and Fig. 11 (b) is a cross section taken along line XX in Fig. 11 (a). 11 (c) and 11 (d) are perspective views showing specific examples of comb-shaped reinforcing bars. It is a perspective view which shows the other Example of the joint between rings. It is a perspective view which shows one Example of the concrete segments which concern on this invention. Fig.14 (a) is a perspective view which shows the internal structure of the other Example of the concrete-made segments based on this invention, FIG.14 (b-1), (b-2), and FIG.14 (c-) 1), (c-2) is a figure explaining the reinforcement aspect using a reinforcing bar. It is a figure explaining the conventional shield tunnel wall body.

  Hereinafter, the concrete segment which can be cut and the wall of a shield tunnel according to the present invention will be described in more detail with reference to the drawings.

Example 1
FIG. 1 shows a part of a shield tunnel wall 100 installed by assembling segments along an inner wall surface of an excavation part by a shield construction method for constructing a tunnel such as a road or a railway while excavating the underground with a shield machine. Indicates. The shield tunnel wall body 100 is configured by connecting a plurality of concrete segments 1 in the circumferential direction and the extension direction (axial direction) of the tunnel.

  FIG. 2 shows one concrete segment 1. Since the concrete segment 1 constitutes a part of the curved circumferential portion of the shield tunnel wall 100, a predetermined radius (R), thickness (H), center angle (θ), and tunnel Are arc-shaped segments extending in the width (W) along the extending direction. Usually, the inner peripheral surface radius (R) is 1 to 15 m, the thickness (H) is 0.1 to 2 m, the central angle (θ) is 10 ° to 100 °, and the width (W) is 0.3. -3 m.

  The cutable concrete segment (hereinafter referred to as “easy-cutting concrete segment”) 1 of the present invention is a shield tunnel wall body 100 having a structure as shown in FIG. For example, it is used in advance in a portion where a cutting by a machine is required, for example, a T-type junction of a pipe line, a branch of a road tunnel, or a junction part.

  3 (A), (a), and (b) show an embodiment of the easily cutable concrete segment 1 of the present invention. The easily cutable concrete segment 1 of the present invention is a concrete segment that can be cut by a shield machine using a concrete 20 as a base material and a fiber reinforced resin reinforcing material as a reinforcing bar 10.

  That is, the easily cutable concrete segment 1 is a concrete structure having a reinforcing bar 10 inside, and the reinforcing bar 10 is located on the inner peripheral surface side of the segment along the vertical direction of the segment (circumferential direction of the tunnel). And the curved rod-shaped inner muscles 11 and outer muscles 12 located on the outer peripheral surface side, and further along the lateral direction of the segment (tunnel extension direction), the inner muscles 11 and the outer muscles. The rod-shaped stirrup 13 is disposed around the inner muscle 11 and the outer muscle 12 so as to be orthogonal to the inner muscle 11 and the outer muscle 12. In FIGS. 3 (A) and 3 (a), a pair of inner and outer muscles 11 and 12 each made of a plurality of muscle materials are shown as the inner and outer muscles 11 and 12 for easy understanding of the drawing. Usually, a plurality of sets, for example, 2 to 5 sets are arranged.

  The inner muscle 11, outer muscle 12 and the like are subjected to R processing and bending processing at the time of manufacturing the muscle material, or are deformed into an R shape by its own weight or external force. And it assembles using a vinyl connection according to the usual rebar rod assembly.

  3 (B), (a), and (b) show another modified example of the easily cutable concrete segment 1 of the present invention.

  In the easily cutable concrete segment 1 shown in FIGS. 3B, 3 </ b> A, and 3 </ b> B, the inner reinforcement 11 and the outer reinforcement 12 are perpendicular to the inner reinforcement 11 and the outer reinforcement 12, respectively. Are arranged and bound by vinyl connection. Further, in this example, the inner muscle 11 and the outer muscle 12 are bound to a U-shaped stirrup 13 by a vinyl connection, and are held apart by a predetermined distance.

  FIG. 3C shows another modification of the easily cutable concrete segment 1 of the present invention.

  In this example, the easy-cutting concrete segment 1 includes assembly bars 15 installed at predetermined intervals along the circumferential direction of the segment. The assembly line 15 has the same configuration as the lattice line 10 which is a fiber-reinforced resin line material formed in a lattice shape to be described later. The lattice line 10 will be described in detail later.

  In FIG. 3 (C), three assembly bars 15 are provided for easy understanding of the drawing. However, the present invention is not limited to this, but usually three to five sets are arranged.

  In this example, when the segment 1 is manufactured, a predetermined number of assembly bars 15 are installed in the circumferential direction on the outer peripheral surface of the mold 90 formed in a convex shape, and the assembly bars 15 are used. The rebar rod can be easily assembled by binding the inner reinforcement 11, the outer reinforcement 12, and the distribution bar 14 with a vinyl connection.

  In addition, in each example of the present embodiment and other modified examples, the cross-sectional shape that is the reinforcing bar 10 is a round or rectangular rod shape, and the inner bar 11, the outer bar 12, the stirrup 13, the power distribution bar 14. The assembly bar 15 is a fiber reinforced resin bar material. The fiber reinforced resin reinforcing material will be described later in detail.

(concrete)
The feature of the present invention lies in the configuration of the concrete 20 which is the base material of the easily cutable concrete segment.

  That is, as described above, the present inventors have conducted many research experiments on concrete in order to reduce wear of the bit. As a result, the lightweight aggregate constituting the coarse aggregate in the concrete, that is, the lightweight coarse bone. It was confirmed that by setting the ratio of the material to a predetermined amount, the torque at the time of cutting by the shield machine rapidly decreases and the vibration is reduced. Hereinafter, an embodiment of concrete used in the present invention will be described.

  In this embodiment, the concrete 20 includes cement, water, and aggregate, and the aggregate includes coarse aggregate and fine aggregate. In addition, if desired, the concrete can further contain 0.01 to 1.0% by volume of resin fibers with respect to the total volume of the concrete. The resin fiber is a short fiber, and the fiber length is usually about 0.5 to 6 cm.

The resin fibers, epoxy resin, or a fiber produced by heat-curable resin such as a vinyl ester resin, or polyamide, polycarbonate, fibers made by polypropylene pin Ren, thermoplastic resin such as PPS Or a fiber made of a thermoplastic epoxy resin.

  As known in the art, the aggregate consists of natural aggregate and artificial aggregate, and as natural aggregate, river sand, river gravel, sea sand, sea gravel, mountain sand, mountain gravel, natural lightweight aggregate, Artificial aggregates include crushed sand, crushed stone, slag sand, slag crushed stone, artificial lightweight aggregate, artificial weight aggregate, and the like.

  In the present specification, basically, “coarse aggregate” means an aggregate of 5 mm or more and 50 mm or less using a 5 mm sieve, and “fine aggregate” means an aggregate of less than 5 mm. It shall be said.

  That is, also in the present invention, according to the conventional regulations, the coarse aggregate has a maximum dimension of 5 to 50 mm, and the fine aggregate has a maximum dimension of less than 5 mm.

  However, since the aggregates in the actual site are mixed in large and small particle sizes, the “coarse aggregate” referred to in the present specification uses a 5 mm sieve and aggregates of less than 5 mm. Means an aggregate containing 85% or more of 5 mm or more and 50 mm or less, and “fine aggregate” means an aggregate of less than 5 mm of 85% or more, 5 mm or more and 10 mm or less of 15% or less. It shall mean the aggregate that contains it.

  The concrete 20 has a water-cement ratio of 20 to 40% by weight as in the conventional case.

  What is important in the present invention is that the coarse aggregate includes a lightweight aggregate (that is, a lightweight coarse aggregate), and the lightweight coarse aggregate is used in an amount of 30 to 100% by weight based on the entire coarse aggregate. . In this embodiment, the lightweight coarse aggregate is an artificial lightweight aggregate containing expanded shale, expanded clay, expanded slate, fired fly ash and the like as material components.

  The inventors of the present invention are composed of (1) lime crushed stone and (2) lightweight coarse aggregate, and the ratio of lime crushed stone and lightweight coarse aggregate is changed to make a fiber reinforced resin. A muscle specimen 1S was produced and subjected to a cutting test. In the cutting test, the cutting test was performed with a cutting test machine using the cutting test equipment shown in FIG.

Here, the bit of the cutting test machine is
-Bit material: E5
-Bit width: 20 mm, tip R: 3 mm
A single-edged flat bit was used. In addition, a new bit was prepared for each condition, and the amount of reduction at the tip of the bit was measured after cutting a certain cutting distance. The results are shown in Table 1 below and FIG.

  As can be seen from the results of Table 1 and FIG. 4 (a), when the proportion of the light coarse aggregate exceeds 30% by weight, particularly when it exceeds 90% by weight, the torque and vibration are reduced sharply during cutting. It could be confirmed. When the amount of lightweight coarse aggregate was less than 30% by weight, there was no significant reduction in torque and vibration during cutting.

  Preferably, in the present invention, the fine aggregate includes a lightweight fine aggregate (hereinafter, the lightweight aggregate as the fine aggregate is referred to as “lightweight fine aggregate”), and the lightweight fine aggregate is referred to as the fine aggregate. Use 5 to 100% by weight based on the whole. In the present embodiment, the lightweight fine aggregate is an artificial lightweight aggregate containing expanded shale, expanded clay, expanded slate, fired fly ash and the like as material components in the same manner as the lightweight coarse aggregate.

  As shown in Table 2 and FIG. 4 (b), it was found that when the proportion of the lightweight fine aggregate exceeds 5% by weight, the wear of the bit during cutting is greatly reduced. When the amount of lightweight fine aggregate was less than 5% by weight, the wear of the bit during cutting was not significantly reduced.

(Fiber-reinforced resin reinforcing material)
In the present embodiment, the rod-shaped fiber reinforced resin reinforcing material used as the inner reinforcement 11, the outer reinforcement 12, the power distribution reinforcement 14, the stirrup 13 and the like constituting the reinforcement reinforcement 10 is aligned in one direction. It is formed by impregnating a resin into the reinforced fibers of long fibers oriented in the above manner.

  The reinforcing fiber is any one of inorganic fibers such as carbon fiber, glass fiber, and basalt fiber, or organic fibers such as aramid, polyester, nylon, and vinylon, or a hybrid type in which a plurality of the fibers are mixed. It is said. As the resin to be impregnated, a thermosetting resin such as an epoxy resin or a vinyl ester resin, a thermoplastic resin such as nylon or PPS, or a thermoplastic epoxy resin is used. The resin impregnation amount for the reinforcing fibers is 20 to 70% by volume.

  The inventors of the present invention changed the cross-sectional area according to the following specifications to produce round and rectangular rod-shaped fiber reinforced resin reinforcing material, embedded in concrete blended according to the present invention, and made of fiber reinforced resin. A muscle specimen 1S was produced. A cutting test was performed on the specimen 1S using a cutting test equipment shown in FIG. 5A in the same manner as described above, with a 20 mm wide single-edged flat bit. Table 3 shows the results.

According to the results of research experiments by the present inventors, as can be seen from Table 3, the fibers forming the rod-shaped inner muscle 11, outer muscle 12, power distribution muscle 14, stirrup 13 and the like which are reinforcing bars 10 It has been found that the reinforcing resin reinforcing material is preferably a round or rectangular rod having a cross-sectional area of 2 mm ² or more and less than 500 mm ² .

When the cross-sectional area of the rod-shaped fiber reinforced resin reinforcing material is 500 mm ² or more, before the fiber reinforced resin reinforcing material is cut with a bit, the concrete around the fiber reinforced resin reinforcing material is dropped first, and the fiber It was found that the fiber reinforced resin reinforcing material vibrates during cutting of the reinforcing resin reinforcing material, so that the vibration during cutting becomes very large. Conversely, if the cross-sectional area of the fiber reinforced resin reinforcing material is smaller than 2 mm ² , the fiber reinforced resin reinforcing material will not be cut properly during cutting, and a phenomenon of entanglement with the bit will occur, resulting in a sharp increase in torque during cutting. Was confirmed.

(Fiber-reinforced resin reinforcing material specimen)
Reinforcing fiber: Carbon fiber (fiber diameter 7μm)
Resin: Epoxy resin Impregnation amount: 50% by volume
(concrete)
Water cement ratio: 30% by weight
Aggregate: Coarse aggregate: Fine aggregate = 53 wt%: 47 wt%
28-day strength (compressive strength): 35 N / mm ²

  Next, the structural stability of the concrete segment according to the present invention was examined.

  Beam fiber (H) 125 mm, carbon fiber reinforced resin reinforcing rods (rods) 11 and 12 having a diameter of 6 mm as tensile reinforcing bars in a concrete segment of the above-mentioned composition is 0.3% by volume. The used specimen 1S was produced. This specimen 1S was subjected to a three-point bending test. FIG. 5B shows a schematic configuration of the three-point bending test apparatus.

  In the three-point bending test, the radius of curvature (R) of the outer curvature of the specimen 1S was 900 mm, and the distance between the two-point supports was 996 mm.

In order to prevent the specimen 1S from being destroyed by shearing, 0.2% by volume of the stirrup 13 that is a carbon fiber reinforced resin reinforcing material (rod) having a diameter of 8 mm was disposed. The strength of the concrete 20 was 50 N / mm ² .

  As a result of the bending test, the specimen 1S was destroyed in the concrete crushing mode, and it was confirmed that the thin carbon fiber reinforced resin reinforcing material functions sufficiently as a tensile reinforcing bar.

(Concrete segment connection)
The concrete segment 1 according to the present invention having the above-described configuration forms the wall 100 of the shield tunnel by connecting to other segments with segment joints in the circumferential direction of the shield tunnel 100 and the extending direction of the shield tunnel 100. To do. Basically, the joint member constituting the segment joint is made of a resin material or a fiber reinforced resin material.

  1, 2, 6 to 9, and FIGS. 10 to 12, as a segment joint, each segment is connected by contacting the end surfaces with each other in the circumferential direction. The joint 50 between pieces (see FIGS. 6 to 9) on which the axial force N and the bending moment M act, and the end faces are connected in the axial direction (extension direction) of the tunnel. There is an inter-ring joint 60 (see FIGS. 10 to 12) that transmits shearing force and exhibits a staggered attachment effect.

Inter- piece joint Inter- piece joint 50 is in an environment where compressive force is applied, but tensile resistance is expected at the joint portion. Basically, joint metal fittings made of resin material or fiber-reinforced resin material are used together. They are joined with bolts, nuts, etc. made of resin material or fiber reinforced resin material.

  In the present embodiment, the following structure is suitably employed as the inter-piece joint 50.

(1) As shown in FIGS. 6 (a) and 6 (b), a fitting hardware 51 and an anchor portion 52 of a resin material or a fiber reinforced resin material (hereinafter referred to as “resin system”) are integrated. Molded and fastened with resin bolts and nuts 53 (53a, 53b).

  That is, as shown in FIG. 6B, a joint metal 51 and an anchor 52, which are integrally molded with a resin-based material or manufactured by an adhesive assembly, are installed on the end face of the segment, and a resin-based bolt and nut is installed. At 53, they are fastened together. In this embodiment, the joint hardware 51 includes a flat plate 51a in which a bolt through hole 54 is formed, and a support plate 51b that is integrally formed perpendicularly to the flat plate 51a in order to attach the anchor portion 52. However, the shape of the joint hardware 51 is not limited to this.

  In this embodiment, the joint hardware 51 is attached to the segment end face by attaching the anchor portion 52 to the segment end face, and the adjacent segments 1 are in contact with each other by the flat plate 51a. Here, the bolts 53a are passed through the bolt holes 54 of the both contact plates 51a, and the two flat plates 51a are fastened by the nuts 53b.

(2) As shown in FIG. 7, a box 59 is provided in a place reserved from the end face of the segment, and is fastened with resin-based bolts and nuts 53 (53a, 53b).

  That is, FIG. 7A-1 is a cross-sectional view of the segments 1 adjacent to each other as viewed in the tunnel extension (axis) direction, and FIG. 7A-2 is a diagram of the segments 1 adjacent to each other. It is the figure seen from the inside of a tunnel.

  Each segment 1 is formed with a rectangular (box-shaped) recess 59 in the present embodiment at a predetermined distance from the contact surface of each segment 1, and penetrates between each box-shaped recess 54. A hole 55 is formed, a bolt 53a is passed from one recess 59 through the through hole 55 to the other recess 59, and a nut 53b is tightened.

  A box-shaped recess 54 is formed in each segment 1 according to the number of bolts 53a to be fastened. In this embodiment, two pieces are formed, but the present invention is not limited to this.

  Moreover, as shown in FIGS. 7B-1 and 7B-2, the box shape formed on the segment end face can be a triangular recess 59, and in this case, between the recesses 59 A curved through hole 55 penetrating through the first concave portion 59 is formed, and a curved bolt 53a is passed from one concave portion 59 through the curved through hole 55 to the other concave portion 59, and the nut 53b can be tightened. Also in this example, the bolt 53a and the nut 53b are made of a resin material.

(3) As shown in FIG. 8A, a resin-based insert hardware 56 is embedded in one segment end face, and a resin-based bolt 53a is inserted in an oblique direction from the other.

  In addition, in the joint between pieces, as shown in FIG.8 (b), it is preferable to install the U-shaped supporting fiber reinforcement bar | burr 17 between the inner and outer muscles 11 and 12. FIG.

(4) As shown in FIG. 9, a plurality of segments 1 </ b> A to be cut were produced from non-cutting segment pieces 1 </ b> B with fiber reinforced resin strands, for example, carbon fiber reinforced resin strands (hereinafter “ It is referred to as “carbon fiber type”.)

  That is, when the through hole 58 for passing the carbon fiber wire 57 is formed in advance in the concrete segment 1A manufactured according to the present invention and the tunnel wall body 100 is formed, the segment piece 1B that is not to be cut. The carbon fiber type wire 57 fixed by the fixing part 57a made of metal or resin is passed through the other end of the wire, and the fixing made of metal or resin of the segment piece 1B that is not to be cut. Fixes to the portion 57b. As a result, the segments 57 can be in close contact with each other and connected.

(5) Although it is set as the structure similar to FIG. 9, a metal wire like a copper wire can be used instead of a carbon fiber-type wire. That is, the segment 1A to be cut can be tightened using the segment piece 1B that is not to be cut using a metal wire, and can be removed immediately before cutting.

Inter-Ring Joint Next, the inter-ring joint 60 in the tunnel axis direction of each segment constituting the tunnel wall 100 will be described.

  As shown in FIG. 1, each segment 1 in the tunnel wall 100 is pressed against the segments 1 by the residual thrust of the shield jack in the tunnel axis direction. Consider the transmission of shear force.

  The side mechanism 61 constituting the inter-ring joint 60 is formed with a convex portion 61a on the end surface extending in the circumferential direction of one adjacent segment 1 that abuts, and extending in the circumferential direction of the other segment 1. It is configured by forming a recess 61b on the end face.

  FIG. 10A-1 is an end view of the circumferential end surface of the segment as viewed in the axial direction of the tunnel, and FIG. 10A-2 is a front view of the circumferential end surface of one segment. . In this example, the convex portion 61a and the concave portion 61b are formed across the end surface. This is a so-called continuous tenon.

  Fig. 10 (b-1) is an end view of the circumferential end surface of the segment as viewed in the axial direction of the tunnel, and Fig. 10 (b-2) is a front view of the circumferential end surface of one segment. . In this example, the convex portion 61a and the concave portion 61b are formed in a circular shape at a substantially central portion of the end surface. It is a so-called partial shape called a saddle type.

  Fig. 10 (c-1) is an end view of the circumferential end surface of the segment as viewed in the axial direction of the tunnel, and Fig. 10 (c-2) is a front view of the circumferential end surface of one segment. . In this example, the convex portion 61a and the concave portion 61b are formed in a track shape in which both ends are semicircular at the substantially central portion of the end surface. This is a so-called oval-type partial tenon.

  FIG. 11 shows the oval mechanism 61 described above with reference to FIGS. 10 (c-1) and 10 (c-2).

  FIG. 11A is a perspective view of the end face of the segment in which the recess 61b is formed. FIG. 11B is a central cross-sectional view taken along the line XX in FIG.

  As shown in FIG. 11 (b), the tenon mechanism 61 of the inter-ring joint 60 is comb-shaped as shown in FIG. 11 (c) above and below the tenon recess 61b, or in FIG. 11 (d). It can be reinforced by inserting a reinforcing bar 62 made of a fiber reinforced resin having a “K” shape as shown.

  Further, in the ring joint 60, at the point where the tensile resistance is required in a curved section or the like, the joint similar to the above (1) to (3) is combined with the above-mentioned hozo mechanism 61 as in the case of the piece joint 50 described above. Can be adopted.

  Further, as shown in FIG. 12, as in the joints (4) and (5) in the case of the piece joint 60 described above, the tensile resistance material 63 is provided between the plurality of segments 1A and 1B adjacent in the tunnel axis direction. Can be installed. The tensile resistance material 63 is a carbon fiber-based wire, and fastens a plurality of segments 1A to be cut from segment pieces 1B that are not to be cut.

  That is, when the through hole 64 for passing the wire 63 is formed in advance in the concrete segment manufactured according to the present invention and the tunnel wall body 100 is formed, the fixing portion 63a of the segment piece 1B that is not to be cut is formed. Through the fixed carbon fiber-based wire 63, the other end of the wire 63 is further fixed to the fixing portion 63b of the segment piece 1B that is not to be cut.

  Furthermore, although it is set as the structure similar to the above-mentioned, it is also possible to use a metal wire such as a PC steel wire instead of a carbon fiber-based wire and remove it immediately before cutting.

(Hanging hardware)
As shown in FIG. 13, an inlet 1a for backfill injection is formed in the segment 1 for use in transporting, hanging up, assembling with an erector, etc., and a hanging hardware 70 can be installed. It is said that.

  According to the present embodiment, the injection port 1a for backfill injection is made of a resin material or a fiber-reinforced resin material, that is, a resin material, and is embedded in the segment 1. On the other hand, as shown in FIG. 13, the hanging hardware 70 is used by embedding a resin female insert 1b on the segment side. That is, in this embodiment, a steel joining jig 70 as a hanging metal fitting is integrally attached and fixed to the segment 1 by screwing four steel bolts 71 into the female insert 1b of the segment. When a large tensile resistance is required for straightening or the like, a plurality of female inserts 1b are embedded, and the shape of the joining jig 70 is used. The hanging hardware 70 may also be made of a resin material.

Example 2
Next, with reference to FIG. 14, a second embodiment of the machinable concrete segment according to the present invention will be described.

  As shown in FIG. 14, the overall configuration and joint structure related to the concrete segment 1 of the present embodiment are the same as the concrete segment 1 and joint structures 50 and 60 described in the first embodiment. Are different in the structure of the reinforcing fiber 10 made of fiber reinforced resin. Accordingly, the description of the first embodiment is used for the entire configuration of the concrete segment 1 and the joint structures 50 and 60, and the description thereof is omitted here. The fiber-reinforced resin reinforcement that constitutes the characterizing portion of this embodiment is used. The muscle 10 will be described.

  In the first embodiment, the reinforcing bar 10 made of fiber reinforced resin is a rod having a round or rectangular cross section. However, a sheet-like lattice bar formed in a lattice shape is provided inside the concrete segment 1 of this embodiment. 10 is arranged.

  In FIG. 14, for the sake of easy understanding of the drawing, the lattice bars 10 are shown as the inner muscles 11 and the outer muscles 12, respectively. A plurality of layers, for example, 2 to 5 layers, are laminated on the inner peripheral side and the outer peripheral side of the segment, respectively.

In addition, the internal reinforcement 11 and the external reinforcement 12 as the lattice reinforcement 10 are made of a fiber reinforced resin material in which a reinforcing fiber having the same configuration as the rod described in the first embodiment is impregnated with resin. In addition, the horizontal stripes 11b and 12b are arranged in a lattice pattern, integrally molded, and hardened. Vertical stripe 11a, 12a and horizontal stripes 11b, 12b, similarly to the case of Example 1, the cross-sectional area is set to 2 mm ² or more 500 mm ² smaller than round or rectangular fiber reinforced resin muscle material. Moreover, the space | interval (w1, w2) of the vertical stripes 11a and 12a and the horizontal stripes 11b and 12b shall be w1, w2 = 5-30 cm.

  As shown in FIGS. 14 (b-1) and 14 (b-2), each of the lattice bars 11 and 12 is provided with a resin base height base 14 (14a, 14b) and laminated on the base 14. It is installed, and the arc-shaped inner muscle 11 and outer muscle 12 are formed by the deflection of its own weight. Of course, each lattice line 11, 12 may be R-processed in advance.

  In addition, when a shear reinforcement is required, as shown in FIGS. 14 (c-1) and 14 (c-2), a stirrup 13 which is a U-shaped fiber-reinforced resin reinforcing material is installed at a necessary place. However, the inner muscle 11 and the outer muscle 12 may be connected.

DESCRIPTION OF SYMBOLS 1 Concrete segment 2 Concrete 10 Reinforcement reinforcement 11 Inner reinforcement 12 Outer reinforcement 13, 14 Star wrap 50 Piece joint 60 Ring joint

Claims (8)

A segment for constructing a wall of a shield tunnel excavated by a shield machine, comprising a part of the curved circumference of the shield tunnel wall, made of concrete and made of fiber reinforced resin In a concrete segment that can be cut by a shield machine with reinforcing bars as reinforcement,
The concrete includes cement, water, and aggregate, and the water-cement ratio is 20 to 40% by weight. The aggregate includes coarse aggregate and fine aggregate. The maximum size of the coarse aggregate is 5 ~ 50 mm, the maximum size of the fine aggregate is less than 5 mm,
The coarse aggregate includes a lightweight coarse aggregate, the lightweight coarse aggregate is used in an amount of 30 to 100% by weight with respect to the entire coarse aggregate, and the fine aggregate includes a lightweight fine aggregate, A lightweight fine aggregate is used in an amount of 5 to 100% by weight based on the whole fine aggregate.
The reinforcing bar is the fiber-reinforced resin reinforcing material that is a round or rectangular rod having a cross-sectional area of 2 mm ² or more and less than 500 mm ² .
A concrete segment characterized by that. The concrete is further a resin fiber 0.01-1.0 vol% saw including the total volume of the concrete,
Whether the resin fiber is a fiber made of a thermosetting resin such as an epoxy resin or a vinyl ester resin, or a fiber made of a thermoplastic resin such as polyamide, polycarbonate, polypropylene, or PPS. The concrete segment according to claim 1 , wherein the concrete segment is a fiber made of a thermoplastic epoxy resin . The fiber-reinforced resin reinforcing material is formed by impregnating a resin into a reinforcing fiber,
The reinforcing fiber is an inorganic fiber such as carbon fiber, glass fiber or basalt fiber, or an organic fiber such as aramid, polyester, nylon or vinylon, or a hybrid in which a plurality of the fibers are mixed. Type
The resin, epoxy resin, thermosetting resin such as a vinyl ester resin, or, nylon, such as PPS thermoplastic resin, or, according to claim 1 or 2, characterized in that a thermoplastic epoxy resin either A concrete segment as described in the paragraph. In the wall of a shield tunnel with a wall region constructed with a concrete segment that can be cut by a shield machine using concrete as a base material and fiber reinforced resin reinforcement as reinforcement,
The said concrete segment is a concrete segment as described in any one of Claims 1-3 , The wall body of the shield tunnel characterized by the above-mentioned. In the circumferential direction of the shield tunnel and the extension direction of the shield tunnel, the concrete segments are connected to other segments by segment joints,
Joint member forming the segment joint, or are made of a resin, or the shield tunneling according to claim 4, characterized in that the resin in the reinforcing fibers are produced by impregnating fiber reinforced resin Wall body. The shield tunnel wall according to claim 5 , wherein the segment joint is a partial side joint, a joint plate, or a bolt. The segment joint is a strand made of fiber reinforced resin in which the fixing portion is made of metal or resin, and the strand is inserted through the connecting segment, the strand is tensioned, and the segments are in close contact with each other. The shield tunnel wall according to claim 5 , wherein the shield tunnel wall is connected. The concrete segment includes a hanging hardware and an inlet for suspending the concrete segment,
The said suspension metal fitting and injection hole are produced with resin, or are produced with the fiber reinforced resin by which resin was impregnated to the reinforced fiber, The term in any one of Claims 4-7 characterized by the above-mentioned. The wall of the shield tunnel described in 1.

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