JP6888928B2 - Segment for cutting site - Google Patents

Description

The present invention relates to a segment for a cutting site that is assembled in the circumferential direction and the axial direction of the wall body in order to form at least a part of the wall body constituting the shield tunnel.

Conventionally, the shield method has been widely adopted when constructing tunnels such as roads and railways or tunnels for constructing sewer pipes. The shield method excavates a tunnel while propelling a shield machine equipped with an excavation blade at the tip underground. Then, while excavating the ground with this shield machine, a tunnel wall body is constructed by sequentially assembling segments along the inner wall surface around the excavated portion (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2001-220999

By the way, a plurality of shield tunnels may be branched or merged. In that case, at the branching / merging portion of each shield tunnel, the overlapping portion of each shield tunnel is cut by a shield machine or the like. At this time, if the segment is made of reinforced concrete, the reinforcing bar becomes an obstacle and it is not easy to cut with a shield machine.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a segment for a cutting portion capable of cutting a part of a shield tunnel when merging / branching the shield tunnel.

The segment for a cutting portion according to the present invention is a segment assembled in the circumferential direction and the axial direction of the wall body in order to form at least a part of the wall body constituting the shield tunnel, and is formed of concrete and has an outer peripheral surface. A segment body having an inner peripheral surface and having axial end surfaces at both ends in the axial direction, and a resin material, which is arranged on the outer peripheral surface side inside the segment body and extends in the circumferential direction. , A plurality of first main bar members arranged at predetermined intervals in the axial direction and a resin material, arranged on the inner peripheral surface side inside the segment body and extending in the circumferential direction. , A plurality of second main bar members arranged at predetermined intervals in the axial direction, and at least one of the outer peripheral surface side surface and the inner peripheral surface side surface of each of the first main bar members. A plurality of first projecting members extending in the axial direction and arranged at predetermined intervals in the circumferential direction, and at least one of the outer peripheral surface side surface and the inner peripheral surface side surface of each of the second main bar members. It includes a plurality of second projecting members that are arranged, extend in the axial direction, and are arranged at predetermined intervals in the circumferential direction.

In the segment for cutting site, the plurality of first projecting members are arranged on the inner peripheral surface side surface of each of the first main bar members, and the plurality of second projecting members are the second main bar members. It can be assumed that it is arranged on the surface on the outer peripheral surface side of the above.

In each of the cutting site segments, the axial lengths of the plurality of first projecting members are the same as the axial lengths of the first main bar members, and the axial lengths of the plurality of second projecting members are the same. Can be the same as the axial length of each of the second main bar members.

In each of the above-mentioned segments for cutting parts, a plurality of first main bar members extending in the axial direction inside the segment body, connecting the plurality of first main bar members, and arranged at predetermined intervals in the circumferential direction. A plurality of second force distribution bars extending in the axial direction inside the segment body, connecting the plurality of second main bar members, and arranged at predetermined intervals in the circumferential direction. A member can be further provided.

In each of the cutting site segments, the relationship between the distance P1 between the first projecting members arranged in the circumferential direction and the width W1 of each first projecting member in the circumferential direction is 3 ≦ P1 / W1 ≦ 7. The relationship between the distance P2 between the second projecting members arranged in the circumferential direction and the width W2 in the circumferential direction of each of the second projecting members satisfies 3 ≦ P2 / W2 ≦ 7. can do.

In each of the above-mentioned segments for cutting parts, it is possible that the outer diameters of both ends of the first and second main bar members in the circumferential direction are formed to be larger than the outer diameters of the other parts.

In the segment for the cutting portion, the distance between the adjacent first main bar members and the distance between the adjacent second main bar members can be 50 to 400 mm.

In each of the cutting site segments, the first and second main bar members are formed in a rectangular cross section, and have an axial length of 30 to 60 mm and a radial length of 19 to 40 mm. It can be.

In each of the cutting site segments, the first and second main bar members may be made of a resin material containing a plurality of fibers extending in the circumferential direction.

According to the cutting site segment according to the present invention, when the shield tunnel is merged or branched, a part of the shield tunnel can be cut.

It is sectional drawing of one Embodiment of the shield tunnel which concerns on this invention. It is a side view of the 1st segment for a non-cut part. It is a figure which looked at the 1st segment of FIG. 2 from the inner peripheral surface side. FIG. 2 is a cross-sectional view taken along the line AA of FIG. It is a front view which looked at the resin muscle structure included in the segment for a cutting part from the axial direction. FIG. 5 is a plan view of the resin muscle structure of FIG. 5 as viewed from the outer peripheral surface side. It is a perspective view which shows the state which two shield tunnels are drilled. It is sectional drawing of a part of the confluence part D of the 1st shield tunnel A. It is a side view of the segment for another cutting part which concerns on this invention. It is a side view of the segment for a cutting part which concerns on Example. FIG. 10 is a plan view of FIG. FIG. 10 is a cross-sectional view of FIG. It is a figure which shows the outline of a bending load test. It is a graph which shows the relationship between the crack width and a load which concerns on Example and comparative example.

Hereinafter, an embodiment of a segment for a cutting portion according to the present invention will be described with reference to the drawings. This segment is used to form at least a part of the wall body of the shield tunnel, and by assembling a plurality of segments in the axial direction and the circumferential direction of the shield tunnel, at least a part of the wall body is formed. ..

<1. Overview of shield tunnel>
FIG. 1 is a cross-sectional view of a shield tunnel according to the present embodiment. As shown in FIG. 1, the wall body constituting this shield tunnel has a plurality of segments having an arcuate cross section, that is, four first segments 10A having a central angle of about 60 degrees and two having a central angle of about 45 degrees. By combining the second segment 10B and the third segment 10C having a central angle of about 20 degrees in the circumferential direction, a wall body having a circular cross section is formed. More specifically, the four first segments 10A are connected in the circumferential direction, and the second segment 10B is connected to the first segment 10A arranged at both ends thereof. A third segment 10C is connected between the two second segments 10B. Further, the axial lengths of the segments 10A to 10C are the same. By assembling the seven segments in this way, a cylindrical tunnel unit is formed.

When assembling the tunnel unit, first, four first segments 10A are connected, and then the second segment 10B is connected to the first segment 10A arranged at both ends. Finally, the third segment 10C is connected between the two second segments 10B. Therefore, in the two second segments 10B, the end faces facing each other are formed so as to be parallel to each other. Therefore, the end faces of the third segment 10C in the circumferential direction are also formed so as to be parallel to each other.

The shield tunnel is formed by connecting the tunnel units in the axial direction. However, in the adjacent tunnel units, the joints between the segments formed in each tunnel unit are arranged so as not to be continuous in the axial direction. That is, in the adjacent tunnel units, the rotation positions of the segments around the axis are connected so as to be different.

As will be described later, the shield tunnel according to the present embodiment merges with the shield tunnel constructed after the fact, so that a part of the wall body can be cut by the shield machine. Therefore, the three segments 10A to 10C constituting the wall body are formed for either the non-cut portion or the cut portion. The segment for the non-cut portion is formed of reinforced concrete, and the segment for the cut portion is formed of concrete containing a resin reinforced concrete. Hereinafter, the segment for the non-cut portion and the segment for the cut portion will be described in detail.

<2. Segments for non-cut parts>
Hereinafter, an example in which the first segment 10A is used as a segment for a non-cutting portion will be described. FIG. 2 is a front view of the first segment for a non-cut portion, FIG. 3 is a view of the first segment of FIG. 2 as viewed from the inner peripheral surface side, and FIG. 4 is a sectional view taken along line AA of FIG.

As shown in FIGS. 2 to 4, the first segment 10A includes a segment main body 1 formed of concrete and a reinforcing bar structure 2 arranged inside the segment main body 1. The segment body 1 is formed in a rectangular cross section having an inner peripheral surface 11 inward in the radial direction, an outer peripheral surface 12 outward in the radial direction, and a pair of axial end surfaces 13 facing in the axial direction. Further, at both ends in the circumferential direction, rectangular end faces 14 in the circumferential direction connected to the other first segment 10A or the second segment 10B are formed. Pins 15 projecting in the axial direction are attached to the axial end surface 13 of any one of the segment main bodies 1 at predetermined intervals in the circumferential direction. Then, on the other axial end surface 13, insertion holes (not shown) into which pins of other segments are inserted are formed at predetermined intervals in the circumferential direction.

On the inner peripheral surface 11 of the segment main body 1, a plate-shaped joint 16 for connecting the segments in the circumferential direction is attached to one end in the circumferential direction. In the present embodiment, the two joints 16 are arranged in the axial direction and are arranged so as to project in the circumferential direction. Each joint 16 can be fixed to the inner peripheral surface 11 of the segment body 1 with bolts, for example. Further, a groove 17 having a semicircular cross section extending in the axial direction is formed on the circumferential end surface of the segment body 1. When the segments are connected in the circumferential direction, the grooves 17 of each segment are combined to form a through hole having a circular cross section. For example, a pipe member made of vinyl chloride or the like filled with mortar can be inserted into the through hole. As a result, the assembled state of the adjacent segment can be maintained together with the joint 16.

Further, a seal groove (not shown) extending along the circumferential direction can be formed on any of the axial end faces 13 of the segment body 1. Then, after connecting the segments in the axial direction, the seal groove can be filled with, for example, a resin seal material. This makes it possible to seal the gaps between the axially adjacent segments. Further, side grooves (not shown) are formed on the end faces in both circumferential directions so as to be continuous with the seal grooves, and the side grooves can also be filled with a resin sealing material. This makes it possible to seal the gaps between the segments connected in the circumferential direction.

A gripping metal fitting 3 is fixed to the inner peripheral surface of the segment main body 1 near the center in the circumferential direction. The gripping hardware 3 is gripped by a transporting device when transporting the first segment 10A.

Further, the segment body 1 can be formed of concrete containing an aggregate. As such an aggregate, for example, the size of the maximum coarse aggregate is preferably 15 mm or less, and more preferably 10 mm or less. In addition to aggregates, fibers such as aramid fibers can also be contained.

Next, the reinforcing bar structure 2 will be described. The reinforcing bar structure 2 is composed of a plurality of sub-bars 21 formed in a rectangular frame shape and a plurality of main bars 22 connecting these sub-bars 21 in the circumferential direction. The auxiliary bar 21 is formed by bending a rod-shaped metal bar bar into a rectangular shape along the inner peripheral surface 11, the outer peripheral surface 12, and the pair of axial end surfaces 13 of the segment body 1. Then, a plurality of auxiliary muscles 21 are arranged in the circumferential direction at predetermined intervals. Further, the main bar 22 is a rod-shaped metal bar, is fixed at a predetermined interval along the inner peripheral edge of the sub bar 21, and extends along the circumferential direction of the segment body 1.

Such a first segment 10A can be manufactured, for example, by arranging the reinforcing bar structure 2 in the formwork and then placing concrete containing the above-mentioned aggregate in the formwork. When the second segment 10B and the third segment 10C are used as segments for non-cutting portions, they are formed in the same manner as described above.

<3. Segment for cutting site>
FIG. 5 is a front view of the resin bar structure included in the segment for the cutting portion as viewed from the axial direction, and FIG. 6 is a plan view of the resin bar structure of FIG. 5 as viewed from the outer peripheral surface side.

Hereinafter, an example in which the first segment 10A is used as a segment for a cutting portion will be described. The first segment 10A includes a segment main body 1 made of concrete and a resin bar structure 40 arranged inside the segment main body 1 and made of a muscular material made of resin. Since the segment body is the same as the segment for the non-cut portion described above, the resin muscle structure will be described below.

As shown in FIGS. 5 and 6, the resin bar structure 40 includes a plurality of resin main bar members 51 and 52 arranged along the circumferential direction of the segment body 1 and along the axial direction of the segment body 1. It is formed by combining a plurality of resin-made force distribution muscle members 61 and 62 and a plurality of resin-made vertical muscle members 7 extending in the radial direction of the segment main body 1. The main bar members 51 and 52 are rod-shaped members having a rectangular cross section extending in an arc shape, and are arranged along the outer peripheral surface side and the inner peripheral surface side of the segment body. Further, the force distribution muscle members 61 and 62 are also rod-shaped members having a rectangular cross section, and are arranged along the outer peripheral surface side and the inner peripheral surface side of the segment. Here, the main bar member arranged on the outer peripheral surface side of the segment main body 1 is referred to as a first main bar member 51, and the main bar member arranged on the inner peripheral surface side is referred to as a second main bar member 52. Further, the force distribution muscle member arranged on the outer peripheral surface side of the segment body 1 is referred to as a first force distribution muscle member 61, and the force distribution muscle member arranged on the inner peripheral surface side is referred to as a second force distribution muscle member 62. I will do it.

The plurality of first main bar members 51 are arranged at predetermined intervals along the axial direction. Similarly, the plurality of second main bar members 52 are also arranged at predetermined intervals along the axial direction. In the present embodiment, four first main bar members 51 and four second main bar members 52 are used, but the number thereof is not particularly limited. The axial lengths of the first and second main bar members 51 and 52 can be, for example, 30 to 60 mm. Further, the radial lengths of the first and second main bar members 51 and 52 can be, for example, 19 to 40 mm. This point can be the same for the force distribution muscle members 61 and 62 and the vertical muscle member 7.

Further, a plurality of rectangular parallelepiped projecting members 81 and 82 are fixed to the inner peripheral surface 511 of each first main bar member 51 and the outer peripheral surface 521 of the second main bar member 52, respectively. Here, the projecting member fixed to the first main bar member 51 is referred to as a first projecting member 81, and the projecting member fixed to the second main bar member 52 is referred to as a second projecting member 82. The plurality of first projecting members 81 extend over the entire length of the first main bar member 51 in the axial direction, and are arranged at predetermined intervals in the circumferential direction. Similarly, the plurality of second projecting members 82 also extend over the entire length of the second main bar member 52 in the axial direction and are arranged at predetermined intervals in the circumferential direction. The height of the first and second projecting members 81 and 82 from the first and second main bar members 51 and 52 can be, for example, 5 to 20 mm. Further, the lengths (widths) W1 and W2 of the first and second projecting members 81 and 82 in the circumferential direction can be, for example, 15 to 80 mm. Further, the interval P1 of the first projecting members 81 arranged in the circumferential direction and the interval P2 of the second projecting members 82 arranged in the circumferential direction can be, for example, 45 to 560 mm. The relationship between W1, W2, P1, and P2 can be as shown in the following equations (1) and (2).
3 ≦ P1 / W1 ≦ 7 (1)
3 ≦ P2 / W2 ≦ 7 (2)

This is because when P1 / W1 and P2 / W2 are smaller than 3, the distance between the projecting members 81 and 82 becomes too small, or the width of the projecting members 81 and 82 is too large, so that the main bar members 51 and 52 This is because the contact area between the surface of the surface and the segment body 1 becomes small, and it is difficult to improve the adhesive force of the main bar members 51 and 52 to the segment body 1. On the other hand, if it is larger than 7, the distance between the projecting members 81 and 82 becomes too large, or the width of the projecting members 81 and 82 is too small, so that the adhesive force of the main bar members 51 and 52 to the segment body 1 is improved. Because it is difficult.

The projecting members 81 and 82 can be fixed to the main bar members 51 and 52 by various means such as adhesives and bolts. In addition, the protruding members 81 and 82 can be formed by cutting the inner peripheral surfaces 511 and the outer peripheral surfaces 521 of the main bar members 51 and 52.

The plurality of first force distribution bar members 61 extend in the axial direction and are arranged at predetermined intervals in the circumferential direction so as to connect the outer peripheral surfaces 512 of the plurality of first main bar members 51. Similarly, the plurality of second force distribution bar members 62 extend in the axial direction and are arranged at predetermined intervals in the circumferential direction so as to connect the inner peripheral surfaces of the plurality of second main bar members 52.

Further, the plurality of vertical bar members 7 are rod-shaped members having a rectangular cross section. The plurality of vertical bar members 7 are arranged at predetermined intervals along the circumferential direction, and connect the first main bar member 51 and the second main bar member 52 arranged on the end face side in the axial direction. .. Specifically, the diameter is such that the axial end surface of the first main bar member 51 arranged on the most axial end surface 13 side with respect to the segment body 1 and the axial end surface of the second main bar member 52 are connected. It extends in the direction. Both ends of each vertical muscle member 7 are fixed to the first main muscle member 51 and the second main muscle member 52 at the positions where the force distribution muscle members 61 and 62 are fixed, respectively.

It is preferable that the main muscle members 51, 52, the force distribution muscle members 61, 62, and the vertical muscle members 7 are arranged in a grid pattern at intervals of about 50 to 400 mm. Further, these members can be fixed to each other with an adhesive, a bolt or the like.

Next, the material constituting the resin muscle structure 40 will be described. Each member constituting the resin streak structure 40 can be a foam molded body made of a foamed resin material containing fibers.

Each member 51, 52, 61, 62, 7 contains a large number of fibers extending in one direction. In the present embodiment, the extending directions of the main bar members 51 and 52, the force distribution bar members 61 and 62, and the vertical bar members 7 and the extending directions of the fibers are substantially the same. This fiber refers to a continuous long fibrous material, and examples thereof include glass fiber, carbon fiber, polyamide fiber, polyester fiber, polyolefin fiber, polyimide fiber, and cellulose fiber. Of these, glass fiber is preferable in terms of heat resistance and cost.

The shape of the fiber is not particularly limited, and examples thereof include roving, roving cloth, mat, strand mat, and non-woven fabric. Of these, roving is preferable in terms of productivity.

The amount of the fiber is not particularly limited, but if it is too small, the rigidity of the obtained foamed molded product is lowered or uneven, and if it is too large, the entire fiber bundle cannot be uniformly impregnated with the foamable resin liquid. Therefore, 20 to 150 parts by weight is preferable with respect to 100 parts by weight of the resin material so that the rigidity does not vary.

The diameter of the fiber is also not particularly limited, but if it is too thin, the fiber will be cut during impregnation, and if it is too thick, the surface area of the fiber will decrease and the adhesion with the foamable resin liquid will decrease. 2 to 100 μm is preferable because the strength of the member is reduced.

Further, as the resin material, for example, a foaming resin liquid containing a foaming agent such as water, which is foamed and cured, can be used. As such a foamable resin liquid, for example, polyurethane resin, phenol resin, polyester resin and the like are preferably used. Further, the foamable resin liquid can contain a solid filler. The solid filler means a short fibrous or powdery filler, for example, inorganic short fibrous materials such as glass fibers, asbestos fibers and mineral fibers, natural fibers such as cotton and hemp, and recycled fibers such as rayon. , Organic short fibers such as synthetic fibers such as polyamide, polyester, and polyolefin, inorganic powders such as calcium carbonate, talc, clay, silica sand, silas balloon, and pebble, and wood flour, bamboo flour, starch, rice bran, etc. Examples thereof include organic powders, mixtures thereof, and cutting chips of long fiber reinforced foam moldings. A typical example of the foamed resin material as described above is Fiber reinforced Foamed Urethane (FFU).

Such a first segment 10A can be manufactured, for example, by arranging the resin bar structure 40 in the formwork and then placing concrete containing the above-mentioned aggregate in the formwork. .. When the second segment 10B and the third segment 10C are used for the cutting portion, they are formed in the same manner as described above.

<4. Structure of the confluence of shield tunnels>
FIG. 7 is a perspective view showing a state in which two shield tunnels are connected. In FIG. 7, the first shield tunnel A is formed by the shield machine W that excavates the second shield tunnel B when the second shield tunnel B that follows is merged with the first shield tunnel A that was constructed in advance. The confluence D is formed by cutting the wall body of the tunnel. Similarly, when the second shield tunnel B is branched from the first shield tunnel A, the wall body of the first shield tunnel A is cut.

FIG. 8 is a cross-sectional view of a part of the confluence D of the first shield tunnel A. In FIG. 8, at the confluence D of the first shield tunnel A, the cutting region by the shield machine W is indicated by the alternate long and short dash line Z. In the cross section shown in FIG. 8, two first segments 10A and one second segment 10B arranged in the cutting region are formed of segments for the cutting portion. The other segments are formed by segments for non-cutting parts. However, which segment is used for the cut portion or the non-cut portion is not limited to this, and can be appropriately determined according to the construction situation.

<5. Features>
According to the above embodiment, the following effects can be obtained.
(1) When a part of the wall body of the shield tunnel is formed by the segment for the cutting part as described above, the resin bar structure 40 included in the segment body 1 for the cutting part has the same strength as the reinforcing bar structure. Since it is possible to cut while holding it, it is possible to cut a part of the wall body with a shield machine for a shield tunnel that follows and merge the shield tunnels.

(2) In the resin bar structure 40 according to the present embodiment, the projecting members 81 and 82 are provided on the main bar members 51 and 52. As a result, when a bending load is applied to the segment, that is, when a load from the radial direction of the tunnel is applied, it is possible to prevent the main bar members 51 and 52 from slipping in the circumferential direction with respect to the segment body 1. It is possible to improve the adhesive force of each of the main bar members 51 and 52 to the segment body 1. As a result, the strength of the segment body 1 against a bending load can be improved, and for example, it is possible to prevent cracks or the like from occurring in the concrete constituting the segment body 1 or the expansion of the cracks that have occurred.

(3) Since the main muscle members 51 and 52, the force distribution muscle members 61 and 62, and the vertical muscle member 7 are formed with a gap between them, the cost of forming the resin muscle structure 40 can be reduced. .. In particular, since the cross-sectional shape and spacing of each member are set as described above, the strength can be maintained even with a small number of members.

<6. Modification example>
Although one embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. The following modifications can be combined as appropriate.

<6-1>
In the above embodiment, the main bar member, the force distribution bar member, and the vertical bar member constituting the resin bar structure are formed of rod-shaped members having a rectangular cross section, but the shape is not particularly limited, and for example, The cross section may be circular.

<6-2>
For the main bar members 51 and 52, for example, as shown in FIG. 9, the outer diameter of the end portion in the circumferential direction can be increased. In this example, the thickness of both ends of the main bar member 51 is increased by laminating a plurality of plate-shaped reinforcing members 9 on the inner peripheral surfaces 511 and the outer peripheral surfaces 512 of both ends of the main bar member 51. As a result, steps are formed at both ends of the main bar member 51, so that the main bar member 51 can be fixed to the segment body 1 when a load is applied to both ends of the segment. However, the method of increasing the outer diameter of the end portion of the main bar member 51 is not particularly limited, and it may be formed so that at least one of the axial direction and the radial direction of the main bar member 51 is increased.

<6-3>
In the above embodiment, the protrusions 81 and 82 are provided on the inner peripheral surface 511 of the first main bar member 51 and the outer peripheral surface 521 of the second main bar member 52, but the present invention is not limited to this, and the outer circumference of the first main bar member 51 is not limited thereto. Protruding members 81 and 82 may be provided on the inner peripheral surface 522 of the surface 512 and the second main bar member 52. However, if the projecting members 81 and 82 are provided on the outer peripheral surface 512 of the first main bar member 51 and the inner peripheral surface 522 of the second main bar member 52, the gap between the projecting members 81 and 82 and the formwork is small when concrete is cast. Therefore, it is preferable to arrange the concrete as in the above embodiment because the concrete may be insufficiently filled.

Further, the axial lengths of the projecting members 81 and 82 are the same as the axial lengths of the main bar members 51 and 52, but they do not necessarily have to be the same, and the projecting members 81 and 82 may be shortened. Alternatively, it may be made to slightly protrude from the main bar members 51 and 52. Further, the cross-sectional shapes of the projecting members 81 and 82 are not particularly limited, and in the above-described embodiment, the cross-sectional shape is rectangular, but it can also be formed into a triangular shape, a polygonal shape, or a curved surface shape.

<6-4>
The number and arrangement of the main bar members 51 and 52, the force distribution bar members 61 and 62, and the vertical bar members 7 constituting the resin bar structure 40 are not particularly limited, and can be appropriately changed in a grid pattern. Further, these members may be made of resin so as to be machinable, and are not limited to the foam molded product described above. Therefore, it is not particularly limited as long as it is a resin material having a predetermined strength. Further, in the present invention, at least the main muscle members 51 and 52 need be provided, and the force distribution muscle members 61 and 62 and the vertical muscle member 7 can be provided as auxiliary.

<6-5>
In the above embodiment, the first to third segments 10A to 10C have been described, but the shape of the segment is not limited to this, and is formed in an arc shape so as to form at least a part of the wall body of the shield tunnel. It suffices if it is done. Further, it may be a partially linear segment.

Hereinafter, examples of the present invention will be described. However, the present invention is not limited to the following examples.

First, as an example, segments for cutting sites as shown in FIGS. 10 to 12 were produced. Here, for the purpose of experiment, the segment is formed so as to extend straight without forming a curve. The main bar member, the force distribution bar member, the vertical bar member, and the protrusion member constituting the resin bar structure were formed of a long glass fiber reinforced plastic foam. The dimensions of each member are as shown in FIGS. 10 to 12.

The concrete constituting the segment body had the following physical characteristics.

The difference between the comparative example and the embodiment is that the protruding member is not provided in the comparative example, and all other points are the same as those in the embodiment.

As shown in FIG. 13, a bending load was applied to the Examples and Comparative Examples formed as described above. That is, a downward load was applied at two locations near the center in the longitudinal direction of each segment. Then, as the load changed, the width of the crack generated at the central point X in the longitudinal direction on the lower surface of each segment was measured. The results are shown in FIG.

As shown in FIG. 14, it can be seen that the width of the cracks in the examples is smaller than that in the comparative examples even when the applied load is large. Therefore, in the embodiment, it can be seen that the provision of the projecting member improves the crack dispersibility or strength against the bending load acting on the segment.

1 Segment body 51 1st main muscle member 52 Type 2 muscle member 61 1st force distribution muscle member 62 2nd force distribution muscle member 81 1st protrusion member 82 2nd protrusion member

Claims (9)

A segment for a cutting site that is assembled in the circumferential direction and the axial direction of the wall body in order to form at least a part of the wall body constituting the shield tunnel.
A segment body formed of concrete, having an outer peripheral surface and an inner peripheral surface, and having axial end surfaces at both ends in the axial direction.
A plurality of first main bar members formed of a resin material, arranged on the outer peripheral surface side inside the segment body, extending in the circumferential direction, and arranged at predetermined intervals in the axial direction.
A plurality of second main bar members formed of a resin material, arranged on the inner peripheral surface side inside the segment body, extending in the circumferential direction, and arranged at predetermined intervals in the axial direction.
A plurality of first projecting members arranged only on the inner peripheral surface side surface of each first main bar member, extending in the axial direction, and arranged at predetermined intervals in the circumferential direction.
A plurality of second projecting members arranged only on the outer peripheral surface side surface of each of the second main bar members, extending in the axial direction, and arranged at predetermined intervals in the circumferential direction.
A segment for cutting sites. The axial length of the plurality of first projecting members is the same as the axial length of each of the first main bar members.
The segment for a cutting portion according to claim 1, wherein the length of the plurality of second projecting members in the axial direction is the same as the length of each of the second main bar members in the axial direction. A plurality of first force distribution muscle members extending in the axial direction inside the segment body, connecting the plurality of first main muscle members, and arranged at predetermined intervals in the circumferential direction.
A plurality of second force distribution muscle members extending in the axial direction inside the segment body, connecting the plurality of second main muscle members, and arranged at predetermined intervals in the circumferential direction.
The segment for a cutting site according to claim 1 or 2, further comprising. The relationship between the distance P1 between the first projecting members arranged in the circumferential direction and the width W1 of each of the first projecting members in the circumferential direction satisfies 3 ≦ P1 / W1 ≦ 7.
Claims 1 to 3 that the relationship between the distance P2 between the second projecting members arranged in the circumferential direction and the width W2 of each of the second projecting members in the circumferential direction satisfies 3 ≦ P2 / W2 ≦ 7. The segment for the cutting site described in any of. The segment for a cutting portion according to any one of claims 1 to 4, wherein the outer diameters of both ends of the first and second main bar members in the circumferential direction are formed to be larger than the outer diameters of the other parts. The segment for a cutting portion according to any one of claims 1 to 5, wherein the distance between the adjacent first main bar members and the distance between the adjacent second main bar members are 50 to 400 mm. Any of claims 1 to 6, wherein the first and second main bar members are formed in a rectangular cross section, and have an axial length of 30 to 60 mm and a radial length of 19 to 40 mm. Segment for cutting site described in Crab. The segment for a cutting portion according to any one of claims 1 to 7, wherein each of the first and second main bar members is formed of a resin material containing a plurality of fibers extending in the circumferential direction. The segment for a cutting portion according to any one of claims 1 to 8, wherein the first main bar member and the second main bar member are formed in a rectangular cross section.

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