JP2023092844A - Synthetic segment and earth-retaining structure - Google Patents

Abstract

To provide a synthetic segment capable of preventing the displacement between a steel shell and concrete, and an earth retaining structure.SOLUTION: The synthetic segment is a synthetic segment for constructing an earth-retaining structure by connecting multiple segments in the circumferential direction and axial direction of the earth-retaining structure, which includes a steel shell and concrete filled inside the steel shell. The steel shell includes: a pair of main girders spaced apart in the axial direction; a skin plate joined to the outer circumference of the main girder; a pair of joint plates joined to both ends of the main girder in the circumferential direction; and a protruding plate that extends in the circumferential direction inside the steel shell and is formed with through-holes. The protruding plate protrudes from the steel shell into the concrete and engages with the concrete.SELECTED DRAWING: Figure 7

Description

The present invention relates to synthetic segments and earth retaining structures used as earth retaining structures such as tunnels.

Conventionally, the urban ring method (registered trademark) is known as a press-in method for earth retaining structures for constructing vertical underground structures. In the urban ring construction method, earth retaining panels are assembled into a ring-shaped structure at the sinking point, and the ring-shaped structure is pressed into the ground with a press-in device. After the ring-shaped structure is pressed into the ground, the inside of the ring-shaped structure is excavated, the soil is removed, and a new ring-shaped structure is added on top of it. An underground structure such as a vertical shaft is constructed by repeating the steps up to.

One of the tunnel construction methods is the shield construction method. In the shield construction method, each time a tunneling machine installed in a vertical shaft advances a certain length, for example, arc-shaped composite segments are assembled into a ring to construct a segment ring at the rear, which is then extended in sequence. This is a method of constructing a shield tunnel by forming a cylindrical lining on the ground.

The composite segment used for the shaft or tunnel as described above is composed of a steel shell having a main girder forming the axial end face of the earth retaining structure, a joint plate forming the circumferential end face, and a skin plate forming the outer peripheral face. It is formed by filling the inside with a filler such as concrete and hardening it (see, for example, Patent Document 1).

JP 2009-074291 A

The composite segment integrates the steel shell and the concrete filled inside the steel shell to exhibit the composite effect of the steel material and the concrete. Therefore, the composite segment integrates the steel shell that constitutes the frame and the concrete that fills the steel shell, prevents the steel shell and concrete from slipping, and has a composite effect that makes them behave in an integrated manner against external forces. It is desired to improve rigidity and strength by making it possible to obtain. In the invention of Patent Document 1, a reinforcing member is used for the main girder in order to suppress the concrete from bulging out to the hollow side. does not have Therefore, according to the invention of Patent Document 1, depending on the size of the synthetic segment or the pressure applied to the synthetic segment, it may not be possible to suppress the swelling caused by the slippage between the skin plate and the concrete, which may cause slippage between the steel shell and the concrete. There is

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a composite segment and earth retaining structure that prevent displacement between the steel shell and the concrete.

The composite segment according to the present invention is a composite segment that constructs an earth retaining structure by connecting a plurality of them in the circumferential and axial directions of the earth retaining structure, and comprises a steel shell and concrete filled inside the steel shell. And, the steel shell comprises a pair of main girders spaced apart in the axial direction, a skin plate joined to the outer peripheral side of the main girder, and a pair of joints joined to both ends of the main girder in the circumferential direction and a protruding plate extending in the circumferential direction inside the steel shell and formed with a hole that is a through hole, the protruding plate protruding from the steel shell into the concrete, It is engaged with concrete.

An earth retaining structure according to the present invention is formed by combining a plurality of the synthetic segments described above in the circumferential direction and the axial direction.

The composite segment of the present invention extends circumferentially within the steel shell and has a protruding plate formed with holes, which are through holes. A protruding plate protrudes from the steel shell into the concrete and engages the concrete. The composite segment can obtain a high fixing effect of the concrete to the steel shell by entering the concrete into the hole, and can prevent the steel shell and the concrete from slipping.

1 is a conceptual diagram of an earth retaining structure according to Embodiment 1. FIG. FIG. 3 is a conceptual diagram of the segment ring according to Embodiment 1 as viewed in the hole axis direction AD; FIG. 2 is a perspective view of an example of a synthetic segment according to Embodiment 1, viewed from the inner peripheral side; FIG. 2 is a perspective view of an example of a synthetic segment according to Embodiment 1, viewed from the outer peripheral side; 4 is a perspective view showing an example of the internal structure of the composite segment according to Embodiment 1; FIG. 4 is a side view showing an example of the internal structure of the composite segment according to Embodiment 1; FIG. 4 is a cross-sectional view showing an example of the internal structure of the composite segment according to Embodiment 1; FIG. FIG. 4 is a plan view of the projecting plate of the composite segment according to Embodiment 1 as viewed in the hole axis direction AD; FIG. 4 is a cross-sectional view showing an example of an internal structure of a first modified example of the composite segment according to Embodiment 1; FIG. 8 is a cross-sectional view showing an example of the internal structure of a second modified example of the composite segment according to Embodiment 1; FIG. 11 is a cross-sectional view showing an example of the internal structure of a third modified example of the composite segment according to Embodiment 1; FIG. 11 is a cross-sectional view showing an example of an internal structure of a fourth modified example of the composite segment according to Embodiment 1; FIG. 8 is a cross-sectional view showing an example of the internal structure of a composite segment according to Embodiment 2; FIG. 11 is a cross-sectional view showing an example of an internal structure of a first modified example of synthetic segment 100 according to Embodiment 2; FIG. 11 is a cross-sectional view showing an example of the internal structure of a second modified example of synthetic segment 100 according to Embodiment 2; FIG. 11 is a cross-sectional view showing an example of an internal structure of a third modified example of synthetic segment 100 according to Embodiment 2;

Hereinafter, synthetic segments according to embodiments will be described with reference to the drawings and the like. In the following drawings including FIG. 1, the relative dimensional relationship and shape of each constituent member may differ from the actual ones. Moreover, in the following drawings, the same reference numerals denote the same or corresponding parts, and this applies throughout the specification. In addition, terms representing directions (eg, up, down, left, right, front, rear, front and back, etc.) are used as appropriate for ease of understanding, but these notations are for convenience of explanation. , the arrangement, direction and orientation of any device, instrument, or component.

Embodiment 1.
[Earth retaining structure 200]
FIG. 1 is a conceptual diagram of an earth retaining structure 200 according to Embodiment 1. FIG. 1 indicates the axial direction of the earth retaining structure 200, and the circumferential direction CD indicates the circumferential direction of the earth retaining structure 200. As shown in FIG. The radial direction RD represents the radial direction of the earth retaining structure 200, the Y1 side represents the inner peripheral side of the earth retaining structure 200, and the Y2 side represents the outer peripheral side of the earth retaining structure 200. there is

The earth retaining structure 200 is used as an earth retaining wall for lining a tunnel, for example, and is installed on the wall surface of an excavation hole formed by excavating natural ground. The earth retaining structure 200 is installed in the ground and used as an earth retaining wall in tunnels, vertical shafts, etc. that constitute subways, road tunnels, water supply and sewerage systems, electric power and communication tunnels, utility tunnels, and the like. Also, the earth retaining structure 200 may be used as an earth retaining wall in a press-fit caisson construction method. When the earth retaining structure 200 is used as an earth retaining wall for a press-in caisson construction method, the earth retaining structure 200 is sunk into the ground by covering an excavated surface in the ground in a construction method such as the press-in construction method.

The earth retaining structure 200 is formed in a tubular shape and has a hollow portion. When the earth retaining structure 200 is used as an earth retaining wall of the press-fit caisson construction method, the earth retaining structure 200 is arranged in the ground such that the cylindrical hole axis direction AD is the vertical direction.

The earth retaining structure 200 is formed in a circular shape when viewed in the hole axis direction AD, and is formed in a cylindrical shape as a whole, but is not limited to a cylindrical shape. If the earth retaining structure 200 is formed in a cylindrical shape, for example, when viewed in the hole axis direction AD, it may have an elliptical shape, an oval shape, or a square shape with rounded corners, or any other shape. may be formed. The earth retaining structure 200 has at least one segment ring 150, or has a plurality of segment rings 150, and the plurality of segment rings 150 are continuously connected in the direction in which the tunnel extends.

[Segment ring 150]
FIG. 2 is a conceptual diagram of the segment ring 150 according to Embodiment 1 viewed in the hole axial direction AD. The segment ring 150 is a structure that covers the excavation surface in the ground. The segment ring 150 is formed in an annular shape when viewed in the hole axial direction AD, and is formed in a tubular shape as a whole. The segment ring 150 is formed in a cylindrical shape, for example, but is not limited to a cylindrical shape.

The earth retaining structure 200 is constructed by connecting a plurality of segment rings 150 along the extending direction of the earth retaining structure 200, that is, along the hole axis direction AD. Note that the earth retaining structure 200 may be composed of one segment ring 150 . When the earth retaining structure 200 is used in, for example, a shield construction method, the earth retaining structure 200 is constructed by arranging segment rings 150 for each round (one ring) of the cross section of the tunnel. Therefore, the segment ring 150 constitutes one unit of the earth retaining structure 200 in the direction in which the tunnel extends.

The segment ring 150 is divided into a plurality of synthetic segments 100 in the circumferential direction CD. That is, a segment ring 150 is formed by arranging a plurality of synthetic segments 100 in a ring shape and connecting adjacent synthetic segments 100 to each other. The segment ring 150 shown in FIG. 2 is described so that the combined segments 100 have approximately the same size in the circumferential direction CD, but the sizes of the combined segments 100 differ depending on the installation position in the circumferential direction CD. It may be formed at

As shown in FIG. 1, in the earth retaining structure 200, the segment rings 150 adjacent in the hole axis direction AD are assembled in an arrangement state in which the positions of the composite segments 100 constituting the segment rings 150 are shifted in the circumferential direction CD. . More specifically, in the earth retaining structure 200, the composite segments 100 forming the segment ring 150 are constructed in a staggered relationship.

[Synthetic segment 100]
FIG. 3 is a perspective view of an example of the composite segment 100 according to Embodiment 1, viewed from the inner peripheral side. FIG. 4 is a perspective view of an example of the synthetic segment 100 according to Embodiment 1 as viewed from the outer peripheral side. FIG. 5 is a perspective view showing an example of the internal structure of synthetic segment 100 according to the first embodiment. FIG. 6 is a side view showing an example of the internal structure of synthetic segment 100 according to the first embodiment. FIG. 7 is a cross-sectional view showing an example of the internal structure of synthetic segment 100 according to the first embodiment. In order to explain the internal structure of the composite segment 100, the illustration of all the concrete 80 is omitted in FIG. 5, and the illustration of the right half of the concrete 80 is omitted in FIG. 7 is a cross-sectional view taken along line AA of FIG. 6. FIG. The synthesized segment 100 will be described with reference to FIGS. 3 to 7. FIG.

The synthetic segments 100 are arranged in an annular shape and connected to each other in the circumferential direction CD to form a tubular segment ring 150 that covers the excavated surface of the ground. A plurality of composite segments 100 are connected in the circumferential direction CD and hole axis direction AD of the earth retaining structure 200 to construct the earth retaining structure 200 . The synthetic segment 100 is a box-shaped structure constructed by combining a plurality of steel materials. The synthetic segment 100 is formed in an arc shape when viewed in the hole axial direction AD of the segment ring 150, and is formed in a curved shape as a whole.

The composite segment 100 has a steel shell 10 and concrete 80 filled inside the steel shell 10 . The composite segment 100 is a composite structure of a box-shaped steel shell 10 and a concrete 80 filled as a filler inside the steel shell 10, and is configured by integrating the steel shell 10 and the concrete 80. It is

The composite segment 100 also has a plurality of main reinforcements 42 extending in the circumferential direction CD in the concrete 80 and spaced apart in the hole axis direction AD. The number of main reinforcing bars 42 is not limited to plural, and may be singular. In addition, the composite segment 100 has a plurality of main reinforcing bars 43 extending in the circumferential direction CD in the concrete 80 and spaced apart in the hole axial direction AD. The number of main reinforcing bars 43 is not limited to plural, and may be singular. The composite segment 100 also has a plurality of force distribution bars 44 extending in the hole axis direction AD and spaced apart in the circumferential direction CD in the concrete 80 . The number of distributing muscles 44 is not limited to plural, and may be singular. In addition, the synthetic segment 100 has a plurality of force distribution bars, which are force distribution bars 45 extending in the hole axis direction AD and provided at intervals in the circumferential direction CD, in the concrete 80 . The number of distributing muscles 45 is not limited to plural, and may be singular.

The composite segment 100 also has a projecting plate 30 projecting inside the steel shell 10 . The synthetic segment 100 may also have a connecting rebar 50 that connects with the projecting plate 30 (see FIG. 9).

As shown in FIG. 5, the steel shell 10 of the composite segment 100 comprises a pair of arc-shaped main girders 11 spaced apart in the hole axis direction AD, and a skin plate 16 joined to the outer peripheral side of the main girder 11. and a pair of joint plates 12 joined to both ends of the main girder 11 in the circumferential direction CD. The steel shell 10 is formed in a box shape by welding and fixing the main girder 11, the joint plate 12, and the skin plate 16 together.

A pair of main girders 11 are portions where adjacent composite segments 100 abut and are portions where adjacent composite segments 100 are connected in the hole axis direction AD of the earth retaining structure 200 and segment ring 150 . The pair of main girders 11 are positioned at both ends of the synthetic segment 100 in the hole axis direction AD of the earth retaining structure 200 and the segment ring 150 . That is, the main girders 11 are provided at both ends of the skin plate 16 in the hole axis direction AD of the earth retaining structure 200 and the segment ring 150, and in the hole axis direction AD, one surface and the other surface of the composite segment 100 are provided. to form

The main girder 11 is formed in a flat plate shape. The main girder 11 is formed in an arc shape in a plan view in the hole axis direction AD according to the cross-sectional shape of the tunnel, and is formed in an annular fan shape. The main girder 11 is formed to extend in the circumferential direction CD and the radial direction RD.

One of the main girders 11 of the pair of main girders 11 is formed with a plurality of bolt holes 13 for connecting vertically adjacent composite segments 100 stacked in the hole axis direction AD. The number of bolt holes 13 is not limited to plural, and may be singular. As an example, one bolt hole 13 is formed in each space partitioned by the shape-retaining material 20 . Further, as shown in FIG. 3 , a bolt box 81 is provided at a portion of the concrete 80 corresponding to the bolt hole 13 . The bolt box 81 forms a space exposing the bolt hole 13 between the concrete 80 and the main girder 11 in the composite segment 100 . The bolt box 81 serves as a work space used for fastening bolts for fastening the main girders 11 of the adjacent combined segments 100 in the hole axis direction AD.

Of the pair of main girders 11, the other main girder 11 is provided with a plurality of bosses 14 for connecting vertically adjacent composite segments 100 stacked in the hole axis direction AD. The number of bosses 14 is not limited to plural, and may be singular. The boss 14 is formed with a mounting hole having an internal thread for threading a bolt.

Composite segments 100 that are adjacent in the hole axial direction AD are bolts provided in bosses 14 using bolt boxes 81 that abut the main girders 11, and the shanks of the bolts inserted through the bolt holes 13 are fastened with nuts. It is connected by concluding. The number of bolt holes 13 and bosses 14 to be formed is not limited to the illustrated example, and is determined in consideration of the size and shape of the composite segment 100, for example. The connection between the composite segments 100 adjacent in the hole axis direction AD is not limited to a structure in which they are connected by bolts and nuts. may be used.

The pair of joint plates 12 is a portion where adjacent composite segments 100 abut and are portions where adjacent composite segments 100 are connected in the circumferential direction CD of the earth retaining structure 200 and the segment ring 150 . A pair of joint plates 12 are members attached to both ends of the composite segment 100 in the circumferential direction CD.

The joint plate 12 is formed in a plate shape and is made of a rectangular steel plate. The joint plate 12 is formed to extend in the hole axial direction AD and the radial direction RD. The joint plate 12 is bridged and fixed between the longitudinal ends of the pair of main girders 11 . The longitudinal direction of the main girder 11 is the circumferential direction CD. A joint for connecting the synthetic segments 100 to form one segment ring 150 may be attached to the end of the synthetic segment 100 where the joint plate 12 is located.

The joint plates 12 are arranged to cover the openings formed by the pair of main girders 11 and the skin plates 16 arranged between the pair of main girders 11 at both ends of the synthetic segment 100 in the circumferential direction CD. there is The joint plates 12 are provided at both ends of the skin plate 16 in the arc direction to form left and right side surfaces of the synthetic segment 100 .

As shown in FIG. 3, the joint plate 12 is formed with a plurality of bolt holes 15 for connecting the laterally adjacent composite segments 100 arranged in the circumferential direction CD of the excavated hole. The number of bolt holes 15 is not limited to plural, and may be singular. Further, as shown in FIG. 3 , a bolt box 82 is provided at a portion of the concrete 80 corresponding to the bolt hole 15 . The bolt box 82 forms a space exposing the bolt hole 15 between the concrete 80 and the joint plate 12 in the composite segment 100 . The bolt box 82 serves as a working space used for fastening bolts for fastening the joint plates 12 of the composite segments 100 adjacent to each other in the circumferential direction CD.

Composite segments 100 that are laterally adjacent in the circumferential direction CD are connected by abutting the joint plates 12 and fastening the shanks of bolts inserted through the bolt holes 15 with nuts. The number of formed bolt holes 15 shown in the figure is an example, and is not limited to this. The connection between the composite segments 100 adjacent in the circumferential direction CD is not limited to a structure in which they are connected by bolts and nuts. may be used.

The skin plate 16 is a plate-like member facing the ground side of the composite segment 100, and is formed by bending a rectangular steel plate into an arc shape in the surface direction. The skin plate 16 is formed in a plate shape having a curved surface. The skin plate 16 is formed to extend in the circumferential direction CD and the hole axial direction AD. The skin plate 16 is formed in a circular arc shape in plan view in the hole axial direction AD and in a square shape in side view in the radial direction RD.

As shown in FIG. 5, the skin plate 16 is joined so as to close the opening of the end face on the ground side of the frame obtained by joining the pair of main girders 11 and the pair of joint plates 12 . That is, the skin plate 16 is attached to the outer peripheral sides of the main girder 11 and the joint plate 12 that constitute the composite segment 100 . The skin plate 16 faces the wall surface of the excavation hole when the composite segment 100 is installed in the ground, and constitutes the peripheral wall of the earth retaining structure 200 on the outer peripheral side.

The steel shell 10 may have a plurality of shape-retaining members 20 joined between the pair of main girders 11 and extending in the hole axis direction AD. The number of shape-retaining members 20 is not limited to plural, and may be singular. Further, the shape retaining member 20 is provided to secure the dimension between the main girders 11 in manufacturing the composite segment 100 . In addition, it is desirable that the composite segment 100 has the shape-retaining material 20 from the viewpoint of strengthening the pressure resistance or from the viewpoint of manufacturing. may not have

The shape retaining member 20 is a member extending in the hole axial direction AD. The shape-retaining member 20 is erected in the direction normal to the surfaces of the main girder 11 and the skin plate 16, and the end of the shape-retaining member 20 is joined to the main girder 11 in the hole axis direction AD. The shape-retaining member 20 is composed of a plate-shaped member such as the one shown in the figure, which is made of a steel plate or the like, or a bar-shaped member made of a reinforcing rod (not shown) or the like.

In the illustrated example, the shape-retaining members 20 are arranged to form a pair with a small interval in the circumferential direction CD. are placed. In other words, the six shape-retaining members 20 are arranged at large and small intervals in the circumferential direction CD. The shape, number and position of the shape retaining members 20 are not limited to the illustrated example, and are determined in consideration of the size and shape of the composite segment 100, for example.

In the synthetic segment 100 according to the embodiment, the shape-retaining member 20 is provided so as to form a gap 60 between itself and the skin plate 16, and the outer reinforcing bars 41, which will be described later, are arranged in the gap 60 and will be described later. The inner reinforcing bar 40 is arranged on the inner peripheral side of the shape retaining member 20 . Note that the composite segment 100 is formed even if the shape-retaining material 20 is joined to the skin plate 16 due to the positional relationship with the outer reinforcing bar 41, and the gap 60 is not formed between the shape-retaining material 20 and the skin plate 16. good.

Composite segment 100 has inner rebar 40 and outer rebar 41 in concrete 80 . The inner reinforcing bar 40 is arranged on the inner peripheral side in the concrete 80 and is composed of a plurality of main reinforcing bars 42 or a plurality of main reinforcing bars 42 and a plurality of distributing reinforcing bars 44 . The outer reinforcing bar 41 is arranged on the outer peripheral side in the concrete 80 and is composed of a plurality of main reinforcing bars 43 or a plurality of main reinforcing bars 43 and a plurality of distributing reinforcing bars 45 . The number of the main reinforcements 42, the main reinforcements 43, the distributing reinforcements 44, and the distributing reinforcements 45 that constitute the inner reinforcing bars 40 and the outer reinforcing bars 41 is not limited to a plurality, and may be singular.

The main reinforcement 42 and the main reinforcement 43 are embedded in the concrete 80 as main steel materials, and arranged so as to extend in the circumferential direction CD of the composite segment 100 . The main reinforcing bars 42 are reinforcing bars arranged on the inner peripheral side (Y1 side) in the radial direction RD, and are also referred to as inner reinforcing bars 40 . A plurality of main reinforcements 42 are provided along the hole axis direction AD of the segment ring 150 . The main reinforcing bars 43 are reinforcing bars arranged on the outer peripheral side in the radial direction RD, and are also referred to as outer reinforcing bars 41 . A plurality of main reinforcements 43 are provided along the hole axis direction AD of the segment ring 150 .

The synthetic segment 100 of the example shown in FIG. Although there is one main reinforcement along the RD, the number of main reinforcements 42 and 43 is not limited to this number. Further, the composite segment 100 may have another main reinforcement arranged between the main reinforcement 42 and the main reinforcement 43 so as to extend in the circumferential direction CD of the composite segment 100 .

The distribution reinforcement 44 and the distribution reinforcement 45 are embedded in the concrete 80 and arranged so as to extend in the hole axial direction AD of the composite segment 100 . The force distributing bar 44 is a reinforcing bar arranged on the inner peripheral side (Y1 side) in the radial direction RD, and is also referred to as an inner reinforcing bar 40 . A plurality of force distribution bars 44 are provided along the circumferential direction CD of the segment ring 150 . The force distributing bar 45 is a reinforcing bar arranged on the outer peripheral side (Y2 side) in the radial direction RD, and is also referred to as the outer reinforcing bar 41 . A plurality of force distribution bars 45 are provided along the circumferential direction CD of the segment ring 150 .

A plurality of force distribution reinforcements 44 are provided in the direction in which the main reinforcements 42 extend, which is the circumferential direction CD. Similarly, the distributing reinforcements 45 are provided in plurality in the direction in which the main reinforcements 43 extend, which is the circumferential direction CD. The composite segment 100 shown in FIG. 5 has six distributing muscles 44 and six distributing muscles 45 along the circumferential direction CD. It is not limited.

The force distributing reinforcement 44 may be formed in a U-shaped bent shape with both ends bent to constrain the plurality of main reinforcements 42 . In the illustrated example, the force distribution reinforcement 44 surrounds and constrains the main reinforcement 42 from the inner peripheral side (Y1 side) in the radial direction RD. In addition, the shape of the force distributing bar 44 is not limited to this shape, and may be formed in a straight line, for example.

The force distributor 45 is formed linearly to extend in the hole axial direction AD. In addition, the shape of the force distributing bar 44 is not limited to this shape, and for example, both ends may be bent to form a U-shaped bent shape.

The force distribution reinforcement 44 and the force distribution reinforcement 45 may be part of a hoop reinforcement formed so as to extend in the radial direction RD and hole axial direction AD of the composite segment 100 . In this case, the force distribution reinforcement 44 is a reinforcement on the inner peripheral side (Y1 side) of the hoop reinforcement, and the distribution reinforcement 45 is a reinforcement on the outer peripheral side (Y2 side) of the hoop reinforcement.

In the composite segment 100, the positional relationship between the main reinforcement 42 and the distributing reinforcement 44 and the positional relationship between the main reinforcement 43 and the distributing reinforcement 45 in the radial direction RD are not limited. For example, the main reinforcement 42 may be located on the outer peripheral side (Y2 side) of the force distribution reinforcement 44 , or the main reinforcement 42 may be located on the inner peripheral side (Y1 side) of the force distribution reinforcement 44 . Similarly, the main reinforcement 43 may be located on the outer peripheral side (Y2 side) of the force distribution reinforcement 45 , and the main reinforcement 43 may be located on the inner peripheral side (Y1 side) of the force distribution reinforcement 45 .

The main reinforcement 42 and the distributing reinforcement 44 are engaged and may be welded to each other. Further, the main reinforcement 42 and the distribution reinforcement 44 are engaged with each other, and may be tied together by a steel wire such as a cord. The main reinforcement 43 and the distribution reinforcement 45 are engaged and may be welded and fixed to each other. Further, the main reinforcement 43 and the distribution reinforcement 45 are engaged with each other and may be tied together by a steel wire such as a wire.

[Anti-slip structure of concrete 80]
(Projection plate 30)
Composite segment 100 has projecting plate 30 . The projecting plate 30 is provided inside the steel shell 10 . The projecting plate 30 extends in the circumferential direction CD inside the steel shell 10 and has a plurality of holes 31 formed along the circumferential direction CD. The number of holes 31 is not limited to plural, and may be singular. The protruding plate 30 protrudes from the steel shell 10 into the concrete 80 and engages with the concrete 80 . In synthetic segment 100 according to Embodiment 1, projecting plate 30 is provided on the inner surface side (Y1 side) of skin plate 16 in radial direction RD. The number of protruding plates 30 provided on the skin plate 16 may be one or plural.

FIG. 8 is a plan view of the projecting plate 30 of the combined segment 100 according to Embodiment 1, viewed in the hole axis direction AD. The protruding plate 30 is made of a flat plate-shaped steel material, and is formed to extend in the circumferential direction CD along the skin plate 16 and to extend in the radial direction RD from the skin plate 16 toward the central portion of the segment ring 150 . . The projecting plate 30 is welded and fixed to the inner surface of the skin plate 16 .

The projecting plate 30 is, for example, a PBL (Perfo-Bond Leisten) dowel. A plurality of holes 31 are formed in the protruding plate 30 along the longitudinal direction of the protruding plate 30, which is the circumferential direction CD. The hole portion 31 forms a hole penetrating the projecting plate 30 in the hole axis direction AD. The hole formed by the hole portion 31 is a circular hole, but the shape of the hole is not limited to the circular hole, and may be a hole of another shape. The synthetic segment 100 functions as a slip stopper for the hole portion 31 of the protruding plate 30 and the concrete 80 .

When the synthetic segment 100 has the shape-retaining material 20 , the tip of the projecting plate 30 may be brought into contact with the shape-retaining material 20 . Further, the protruding plate 30 may be joined to the shape-retaining member 20 at the tip in the protruding direction. By bringing the tip of the projecting plate 30 into contact with the edge of the shape-retaining member 20 in the radial direction RD, the strength against abdominal pressure applied to the composite segment 100 can be improved.

The projecting plate 30 and the shape retaining member 20 may be joined by welding or the like, or may not be joined by welding or the like. When the protruding plate 30 and the shape-retaining member 20 are joined by welding or the like, the strength can be further secured as compared with the case where they are not joined.

Here, the abdominal pressure is the force applied to the center of the earth retaining structure 200 when a tensile force is generated in the main reinforcements arranged in the earth retaining structure 200 in the section where the earth retaining structure 200 formed in a cylindrical shape undergoes positive bending. It is the secondary normal force directed in the direction. In other words, the abdominal pressure is defined as the pressure in the central direction of the earth retaining structure 200 when tensile force is generated in the main reinforcements arranged in the earth retaining structure 200 in the section where the cylindrical earth retaining structure 200 is subjected to tension. It is the secondary normal force directed towards.

(Connecting reinforcing bar 50)
FIG. 9 is a cross-sectional view showing an example of the internal structure of a first modified example of synthetic segment 100 according to Embodiment 1. As shown in FIG. The composite segment 100 may have connecting rebars 50 as shown in FIG. The connecting reinforcing bars 50 are reinforcing bars that bridge the inner reinforcing bars 40 and the projecting plate 30 . Moreover, the connecting reinforcing bar 50 is a reinforcing bar that connects the inner reinforcing bar 40 and the projecting plate 30 . Here, the inner reinforcing bar 40 to which the connecting reinforcing bar 50 connects is the main reinforcing bar 42 arranged on the inner side (Y1 side) in the radial direction RD. In addition, the inner reinforcing bar 40 to which the connecting reinforcing bar 50 connects may be connected to the distributing bar 44 arranged on the inner side (Y1 side) in the radial direction RD.

The connecting reinforcing bars 50 are reinforcing bars extending in the radial direction RD in the composite segment 100 . The connecting reinforcing bars 50 are bent at both ends and formed in a U-shape as a whole. The connecting reinforcing bars 50 are bent at both ends and formed to extend in the hole axial direction AD. Since the connecting reinforcing bar 50 is formed in a U-shape, one end of the connecting reinforcing bar 50 is hooked on the inner reinforcing bar 40 and the other end is inserted through the hole 31 of the protruding plate 30 when manufacturing the composite segment 100 . As a result, the connecting reinforcing bars 50 are engaged with the inner reinforcing bars 40 and the protruding plate 30 . Therefore, since the connecting reinforcing bars 50 are formed in a U-shape, the connecting reinforcing bars 50 can be easily installed in the steel shell 10, and the composite segment 100 can be easily manufactured.

The connecting reinforcing bars 50, the inner reinforcing bars 40, and the protruding plate 30 are not joined by welding or the like. 40 and projecting plate 30 are joined together. Note that the connecting reinforcing bars 50, the inner reinforcing bars 40, and the projecting plate 30 may be joined by welding or the like before the concrete 80 is placed.

9 shows an example in which the connecting reinforcing bars 50 are formed in a U shape, but the shape of the connecting reinforcing bars 50 is not limited as long as it connects the inner reinforcing bars 40 and the projecting plate 30. For example, the connecting reinforcing bars 50 may be formed in a straight center and bent so that both ends face opposite directions. Alternatively, the connecting reinforcing bars 50 may be formed in a straight line and both ends thereof may be joined to the inner reinforcing bars 40 and the protruding plate 30 by welding or the like. Moreover, the connecting reinforcing bar 50 may be rod-shaped or plate-shaped.

In the illustrated example, two connecting reinforcing bars 50 are arranged with an interval in the hole axis direction AD. The number of connection reinforcing bars 50 installed in the hole axis direction AD is not limited to the illustrated example, and is determined in consideration of the size and shape of the composite segment 100, for example. Also, the number of connecting reinforcing bars 50 to be installed in the circumferential direction CD is determined in consideration of, for example, the size and shape of the composite segment 100 .

[Action and effect of synthetic segment 100]
The synthetic segment 100 extends in the circumferential direction CD inside the steel shell 10 and has a protruding plate 30 formed with a hole portion 31 which is a through hole. The protruding plate 30 protrudes from the steel shell 10 into the concrete 80 and engages with the concrete 80 . The composite segment 100 can obtain a high fixing effect of the concrete 80 to the steel shell 10 by entering the concrete 80 into the hole 31, and can prevent the steel shell 10 and the concrete 80 from slipping.

In addition, the steel shell 10 has shape-retaining members 20 joined between the pair of main girders. Therefore, the synthetic segment 100 can improve the strength of the steel shell 10 by the shape-retaining material 20, and can secure the dimension between the main girders 11 in manufacturing the synthetic segment 100.

Moreover, the protruding plate 30 is joined to the shape retaining member 20 at the tip in the protruding direction. In the synthetic segment 100, the tip portion of the protruding plate 30 and the shape-retaining member 20 are joined together in the radial direction RD, so that the synthetic segment 100 can be improved in strength against intra-abdominal pressure.

Further, the synthetic segment 100 is provided in the concrete 80 with main reinforcing bars extending in the circumferential direction CD and distributing reinforcing bars extending in the hole axis direction AD. The synthetic segment 100 can improve the strength of the concrete 80 by having this configuration.

In addition, the composite segment 100 is arranged in the concrete 80 on the inner peripheral side and is composed of the main reinforcement 42, or the main reinforcement 42 and the distributing reinforcement 44, and the inner reinforcing bar 40 arranged on the outer peripheral side, the main reinforcement 43, or , and outer reinforcing bars 41 composed of main bars 43 and distributing bars 45 are provided. The synthetic segment 100 can improve the strength of the concrete 80 by having this configuration.

The composite segment 100 also has connecting reinforcing bars 50 in the concrete 80 that connect the inner reinforcing bars 40 and the projecting plate 30 . The composite segment 100 can improve strength against abdominal pressure applied to the earth retaining structure 200 by having the connecting reinforcing bars 50 . That is, the composite segment 100 can achieve both anti-slippage of the concrete 80 by having the protruding plate 30 and improvement of strength against abdominal pressure by having the connecting reinforcing bars 50 using the protruding plate 30 .

In addition, the connecting reinforcing bars 50 are bent at both ends to form a U-shape. ing. Therefore, since the connecting reinforcing bars 50 are formed in a U-shape, the connecting reinforcing bars 50 can be easily installed in the steel shell 10 when manufacturing the composite segment 100, and the manufacturing of the composite segment 100 is facilitated.

Also, the projecting plate 30 is provided on the skin plate 16 . Since the projecting plate 30 is provided on the skin plate 16, it is easy to install the projecting plate 30 on the skin plate 16, which is the bottom plate side, when manufacturing the synthetic segment 100. Therefore, the projecting plate 30 is provided on other parts. Manufacture of synthetic segment 100 is facilitated as compared to the case. Moreover, since the projecting plate 30 is provided on the skin plate 16 , the rigidity of the skin plate 16 is increased, and the strength against pressure of the composite segment 100 can be enhanced.

In addition, since the earth retaining structure 200 has the composite segment 100, the effect of the composite segment 100 described above can be exhibited.

The synthetic segment 100 of the first modified example has the outer reinforcing bars 41, but the outer reinforcing bars 41 are not included due to the strength required by the synthetic segment 100 or the size of the synthetic segment 100. You don't have to. Further, as shown in FIG. 9 , the composite segment 100 of the first modified example has both the main reinforcing bars 42 and the distributing bars 44 as the inner reinforcing bars 40 . However, the synthetic segment 100 of the first modified example has only one of the main reinforcement 42 and the distributing reinforcement 44 in relation to the strength required by the synthetic segment 100 or the size of the synthetic segment 100. You may have

FIG. 10 is a cross-sectional view showing an example of the internal structure of a second modification of synthetic segment 100 according to Embodiment 1. As shown in FIG. The composite segment 100 may be installed by welding the main bars 43 of the outer reinforcing bars 41 to the skin plate 16 as shown in FIG. FIG. 11 is a cross-sectional view showing an example of the internal structure of a third modified example of synthetic segment 100 according to Embodiment 1. As shown in FIG. As shown in FIG. 11 , the synthetic segment 100 may not have the shape retaining material 20 in relation to the strength required by the synthetic segment 100 or the size of the synthetic segment 100 .

FIG. 12 is a cross-sectional view showing an example of the internal structure of a fourth modified example of synthetic segment 100 according to Embodiment 1. As shown in FIG. As shown in FIG. 12, the synthetic segment 100 does not have the inner reinforcing bars 40 and the outer reinforcing bars 41 in relation to the strength required by the synthetic segment 100 or the size of the synthetic segment 100. good.

Embodiment 2.
FIG. 13 is a cross-sectional view showing an example of the internal structure of synthetic segment 100 according to the second embodiment. Components having the same functions and actions as those of the synthetic segment 100 according to Embodiment 1 are denoted by the same reference numerals, and descriptions thereof are omitted. Hereinafter, the differences of the second embodiment from the first embodiment will be mainly described with reference to FIG.

(Protruding plate 30a)
The synthetic segment 100 has a projecting plate 30a. The projecting plate 30 a is provided inside the steel shell 10 . In the composite segment 100, the protruding plate 30a protrudes from the steel shell 10 toward the inside of the concrete 80 and engages with the concrete 80. As shown in FIG. In the composite segment 100 according to Embodiment 2, a projecting plate 30a is provided on the inner surface side of the main girder 11 in the hole axis direction AD. The number of protruding plates 30a provided on the main girder 11 may be one or plural.

The protruding plate 30a is made of a flat steel material and extends along the main girder 11 in the circumferential direction CD. In addition, the projecting plate 30a protrudes from one main girder 11 of the pair of main girder 11 toward the other main girder 11 . The projecting plate 30a is welded and fixed to the inner surface of the main girder 11 .

The projecting plate 30a is, for example, a PBL (Perfo-Bond Leisten) dowel. A plurality of holes 31a are formed in the protruding plate 30a along the longitudinal direction of the protruding plate 30a, which is the circumferential direction CD. The number of holes 31a is not limited to plural, and may be singular. The hole portion 31a forms a hole penetrating the projecting plate 30a in the radial direction RD. The hole formed by the hole portion 31a is a circular hole, but the shape of the hole is not limited to a circular hole, and may be a hole of another shape. In the composite segment 100, the hole 31a of the protruding plate 30a functions as a slip stopper with respect to the concrete 80. As shown in FIG.

(Connecting reinforcing bar 50a)
FIG. 14 is a cross-sectional view showing an example of the internal structure of the first modified example of synthetic segment 100 according to the second embodiment. The composite segment 100 may have connecting rebars 50a as shown in FIG. The connecting reinforcing bar 50a is a reinforcing bar that bridges the inner reinforcing bar 40 and the projecting plate 30a. Moreover, the connecting reinforcing bar 50a is a reinforcing bar that connects the inner reinforcing bar 40 and the projecting plate 30a. Here, the inner reinforcing bar 40 to which the connecting reinforcing bar 50a is connected is the main reinforcing bar 42 arranged on the inner side (Y1 side) in the radial direction RD. The inner reinforcing bar 40 to which the connecting reinforcing bar 50a connects may be connected to the distributing bar 44 arranged on the inner side (Y1 side) in the radial direction RD.

The connecting reinforcing bar 50a is a reinforcing bar extending in the hole axial direction AD in the composite segment 100. As shown in FIG. The connecting reinforcing bars 50a are bent at both ends and formed in a U-shape as a whole. Both ends of the connecting reinforcing bar 50a are bent and formed to extend in the radial direction RD. Since the connecting reinforcing bar 50a is formed in a U-shape, one end of the connecting reinforcing bar 50a is hooked on the inner reinforcing bar 40, and the other end is inserted through the hole 31a of the protruding plate 30a. , the inner reinforcing bar 40 and the protruding plate 30a. Therefore, since the connecting reinforcing bars 50a are formed in a U-shape, the connecting reinforcing bars 50a can be easily installed in the steel shell 10, and the composite segment 100 can be easily manufactured.

The connecting reinforcing bars 50a, the inner reinforcing bars 40, and the protruding plate 30a are not joined by welding or the like. 40 and the projecting plate 30a are joined. Note that the connecting reinforcing bars 50a, the inner reinforcing bars 40, and the protruding plate 30a may be joined by welding or the like before the concrete 80 is placed.

Although the connecting reinforcing bar 50a shown in FIG. 14 shows an example formed in a U shape, the shape of the connecting reinforcing bar 50a is not limited as long as it connects the inner reinforcing bar 40 and the projecting plate 30a. For example, the connecting reinforcing bars 50a may be formed in a straight center and bent so that both ends face opposite directions. Alternatively, the connecting reinforcing bar 50a may be formed in a straight line and both ends thereof may be joined to the inner reinforcing bar 40 and the protruding plate 30a by welding or the like. Moreover, the connecting reinforcing bar 50a may be rod-shaped or plate-shaped.

Two connecting reinforcing bars 50a are arranged with an interval in the hole axis direction AD. The composite segment 100 includes a connecting reinforcing bar 50a that engages with a protruding plate 30a provided on one of the main girders 11 of the pair of main girders 11, and another connecting reinforcing bar 50a that engages with the protruding plate 30a provided on the other main girder 11 of the pair of main girders 11. and connecting reinforcing bars 50a. However, the composite segment 100 may have only one of the connecting reinforcing bars 50a, for example, considering the size and shape of the composite segment 100, and the like. The number of connecting reinforcing bars 50a installed in the circumferential direction CD is determined in consideration of the size and shape of the combined segment 100, for example.

(Connecting reinforcing bar 50b)
FIG. 15 is a cross-sectional view showing an example of the internal structure of a second modified example of synthetic segment 100 according to the second embodiment. The composite segment 100 may have connecting rebars 50b as shown in FIG. The connecting reinforcing bar 50b is a reinforcing bar that bridges the inner reinforcing bar 40 and the projecting plate 30a. Further, the connecting reinforcing bar 50b is a reinforcing bar that connects the inner reinforcing bar 40 and the projecting plate 30a.

The connecting reinforcing bar 50b is a reinforcing bar extending in the radial direction RD in the composite segment 100. As shown in FIG. The connecting reinforcing bar 50b is bent at both ends and formed in a U-shape as a whole. The connecting reinforcing bars 50b are bent at both ends and are formed so as to extend in the hole axial direction AD. Since the connecting reinforcing bar 50b is formed in a U-shape, one end of the connecting reinforcing bar 50b is hooked on the inner reinforcing bar 40, and the other end is inserted through the hole 31a of the protruding plate 30a. , the inner reinforcing bar 40 and the protruding plate 30a. Therefore, since the connecting reinforcing bars 50b are formed in a U-shape, the connecting reinforcing bars 50b can be easily installed in the steel shell 10, and the composite segment 100 can be manufactured easily. In addition, in the composite segment 100 of the second modified example, the linearly extending body portion 50b1 of the connecting reinforcing bar 50b is inserted through the hole portion 31a of the protruding plate 30a.

The connecting reinforcing bars 50b, the inner reinforcing bars 40, and the protruding plate 30a are not joined by welding or the like. 40 and the projecting plate 30a are joined. Note that the connecting reinforcing bars 50b, the inner reinforcing bars 40, and the projecting plate 30a may be joined by welding or the like before the concrete 80 is placed.

Although the connecting reinforcing bar 50b shown in FIG. 15 shows an example formed in a U-shape, the connecting reinforcing bar 50b is not limited in shape as long as it connects the inner reinforcing bar 40 and the projecting plate 30a. For example, the connecting reinforcing bar 50b may be formed in a straight center and bent so that both ends face opposite directions. Alternatively, the connecting reinforcing bar 50b may be formed in a straight line and both ends thereof may be joined to the inner reinforcing bar 40 and the protruding plate 30a by welding or the like. Moreover, the connecting reinforcing bar 50b may be rod-shaped or plate-shaped.

Two connecting reinforcing bars 50b are arranged with an interval in the hole axis direction AD. The composite segment 100 includes a connecting reinforcing bar 50b that engages with the protruding plate 30a provided on one main girder 11 of the pair of main girders 11, and another connecting reinforcing bar 50b that engages with the protruding plate 30a provided on the other main girder 11 of the pair of main girders 11. and a connecting reinforcing bar 50b. However, the composite segment 100 may have only one of the connection reinforcing bars 50b, for example, considering the size and shape of the composite segment 100, and the like. The number of connecting reinforcing bars 50b installed in the circumferential direction CD is determined, for example, in consideration of the size and shape of the composite segment 100, and the like.

The composite segment 100 of the first modification and the second modification according to the second embodiment has the outer reinforcing bar 41, but the strength required by the composite segment 100 or the size of the composite segment 100 is not sufficient. It is not necessary to have the outer reinforcing bars 41 in relation to the ribs. In addition, the composite segment 100 according to Embodiment 2 has both the main reinforcing bars 42 and the distributing bars 44 as the inner reinforcing bars 40 . However, in the composite segment 100 according to the second embodiment, only one of the main reinforcement 42 and the distributing reinforcement 44 is used in relation to the strength required by the composite segment 100 or the size of the composite segment 100. may have.

(Connecting reinforcing bar 50c)
FIG. 16 is a cross-sectional view showing an example of the internal structure of a third modified example of synthetic segment 100 according to Embodiment 2. As shown in FIG. As shown in FIG. 16 , the composite segment 100 may be provided with a connecting reinforcing bar 50c that penetrates the hole 31a of the protruding plate 30a and connects the inner reinforcing bar 40 and the outer reinforcing bar 41 in the concrete 80 . The connecting reinforcing bar 50c is a reinforcing bar that bridges the inner reinforcing bar 40, the outer reinforcing bar 41, and the projecting plate 30a. Moreover, the connecting reinforcing bar 50c is a reinforcing bar that connects the inner reinforcing bar 40, the outer reinforcing bar 41, and the projecting plate 30a.

The connecting reinforcing bar 50c is a reinforcing bar extending in the radial direction RD in the composite segment 100. As shown in FIG. The connecting reinforcing bar 50c is bent at both ends and formed in a U-shape as a whole. The connecting reinforcing bars 50c are bent at both ends and formed to extend in the hole axial direction AD. In the composite segment 100 of the third modified example, the linearly extending body portion 50c1 of the connecting reinforcing bar 50c is inserted through the hole portion 31a of the protruding plate 30a.

When manufacturing the composite segment 100 of the third modification, one end of the connecting reinforcing bar 50c is hooked to the inner reinforcing bar 40, the main body portion 50c1 is inserted through the hole 31a of the protruding plate 30a, and the other end of the connecting reinforcing bar 50c is attached to the outer reinforcing bar 41. be hooked on In the synthetic segment 100 of the third modified example, the connecting reinforcing bar 50c, the inner reinforcing bar 40, the outer reinforcing bar 41, and the protruding plate 30a are engaged. In the composite segment 100 of the third modification, the connecting reinforcing bars 50c are formed in a U-shape, so that the connecting reinforcing bars 50c can be easily installed in the steel shell 10, and the composite segment 100 can be manufactured easily.

The connecting reinforcing bars 50c, the inner reinforcing bars 40, the outer reinforcing bars 41, and the projecting plate 30a are not joined by welding or the like. The connecting reinforcing bars 50c, the inner reinforcing bars 40, the outer reinforcing bars 41, and the protruding plate 30a are joined by pouring concrete 80 into the steel shell 10 and hardening the concrete 80. As shown in FIG. The connecting reinforcing bars 50c, the inner reinforcing bars 40, the outer reinforcing bars 41, and the protruding plate 30a may be joined by welding or the like before the concrete 80 is placed.

Although the connecting reinforcing bar 50c shown in FIG. 16 shows an example formed in a U-shape, the connecting reinforcing bar 50c may connect the inner reinforcing bar 40, the outer reinforcing bar 41, and the projecting plate 30a. The shape of the blade is not limited. For example, the connecting reinforcing bars 50c may be formed in a straight center and bent so that both ends face opposite directions. Alternatively, the connecting reinforcing bar 50c may be formed in a straight line and both ends thereof may be joined to the inner reinforcing bar 40 and the outer reinforcing bar 41 by welding or the like. Moreover, the connecting reinforcing bar 50c may be rod-shaped or plate-shaped.

Two connecting reinforcing bars 50c are arranged with an interval in the hole axial direction AD. The composite segment 100 includes a connecting reinforcing bar 50c that engages with the protruding plate 30a provided on one main girder 11 of the pair of main girders 11, and another connecting reinforcing bar 50c that engages with the protruding plate 30a provided on the other main girder 11. and a connecting reinforcing bar 50c. However, the composite segment 100 may have only one of the connection reinforcing bars 50c, for example, considering the size and shape of the composite segment 100, and the like. The number of connecting reinforcing bars 50c to be installed in the circumferential direction CD is determined in consideration of the size and shape of the composite segment 100, for example.

[Action and effect of synthetic segment 100]
The composite segment 100 extends in the circumferential direction CD inside the steel shell 10 and has a projecting plate 30a in which a plurality of holes 31 are formed along the circumferential direction CD. The protruding plate 30 a protrudes from the steel shell 10 into the concrete 80 and engages with the concrete 80 . The composite segment 100 can obtain a high fixing effect of the concrete 80 to the steel shell 10 by entering the concrete 80 into the hole 31, and can prevent the steel shell 10 and the concrete 80 from slipping.

The composite segment 100 according to Embodiment 2 has, in the concrete 80, a connecting reinforcing bar 50a, a connecting reinforcing bar 50b, or a connecting reinforcing bar 50c that connects the inner reinforcing bar 40 and the protruding plate 30 together. The composite segment 100 can improve the strength against abdominal pressure applied to the earth retaining structure 200 by having the connecting reinforcing bars 50a, the connecting reinforcing bars 50b, or the connecting reinforcing bars 50c. That is, the synthetic segment 100 according to the second embodiment has both the anti-slippage of the concrete 80 by having the protruding plate 30a and the improvement of the strength against abdominal pressure by having the connecting reinforcing bars 50a and the like using the protruding plate 30a. can be achieved.

Further, the synthetic segment 100 is provided with a connecting reinforcing bar 50c which is inserted through the hole 31a of the protruding plate 30a in the concrete 80 and connects the inner reinforcing bar 40 and the outer reinforcing bar 41 together. The synthetic segment 100 can improve the strength of the concrete 80 by having this configuration.

The connecting reinforcing bars 50a are bent at both ends to form a U-shape. ing. Therefore, since the connecting reinforcing bars 50a are formed in a U-shape, the connecting reinforcing bars 50a can be easily installed in the steel shell 10 when manufacturing the composite segment 100, and the manufacturing of the composite segment 100 is facilitated.

In addition, the connecting reinforcing bars 50b and 50c are bent at both ends to form a U-shape. ing. Therefore, since the connecting reinforcing bars 50b and the connecting reinforcing bars 50c are formed in a U-shape, it becomes easier to install the connecting reinforcing bars 50b and the connecting reinforcing bars 50c in the steel shell 10 when manufacturing the composite segment 100, and the composite segment 100 is easier to manufacture.

Also, the projecting plate 30 a is provided on the main girder 11 . Since the projecting plate 30a is provided on the main girder 11, the rigidity of the main girder 11 is increased, and the pressure resistance strength of the composite segment 100 can be enhanced. In addition, since the protruding plate 30a is provided on the main girder 11, it becomes easier to install the U-shaped connecting reinforcing bars 50a and the like on the protruding plate 30a. facilitating the manufacture of composite segment 100.

In addition, since the earth retaining structure 200 has the composite segment 100, the effect of the composite segment 100 described above can be exhibited.

The configuration shown in the above embodiment is an example, and can be combined with another known technique, and part of the configuration can be omitted or changed without departing from the scope of the invention. It is possible.

10 steel shell, 11 main girder, 12 joint plate, 13 bolt hole, 14 boss, 15 bolt hole, 16 skin plate, 20 shape retaining member, 30 projecting plate, 30a projecting plate, 31 hole, 31a hole, 40 inner side Reinforcing bar 41 Outer reinforcing bar 42 Main reinforcing bar 43 Main reinforcing bar 44 Distributing bar 45 Distributing bar 50 Connecting reinforcing bar 50a Connecting reinforcing bar 50b Connecting reinforcing bar 50b1 Main body 50c Connecting reinforcing bar 50c1 Main body 60 Gap 80 Concrete, 81 bolt box, 82 bolt box, 100 synthetic segment, 150 segment ring, 200 earth retaining structure, AD hole axial direction, CD circumferential direction, RD radial direction.

Claims (12)

A synthetic segment that constructs the earth retaining structure by connecting a plurality of segments in the circumferential direction and the axial direction of the earth retaining structure,
a steel shell;
and concrete filled inside the steel shell,
The steel shell is
a pair of main girders spaced apart in the axial direction;
a skin plate joined to the outer peripheral side of the main girder;
a pair of joint plates joined to both ends of the main girder in the circumferential direction;
a protruding plate extending in the circumferential direction inside the steel shell and having a through hole formed therein;
has
The projecting plate is
A composite segment projecting from the steel shell into the concrete and engaging the concrete. The steel shell is
2. A composite segment according to claim 1, comprising a shape retaining member joined between said pair of main girders. The projecting plate is
The synthetic segment according to claim 2, wherein a tip portion in a projecting direction is joined to the shape-retaining material. In the concrete,
a main reinforcement extending in the circumferential direction;
A composite segment according to any one of claims 1 to 3, wherein said axially extending force distribution bars are provided. In the concrete,
an inner reinforcing bar arranged on the inner peripheral side and composed of the main reinforcing bar or the main reinforcing bar and the distributing bar;
5. The synthetic segment according to claim 4, further comprising an outer reinforcing bar arranged on the outer peripheral side and composed of the main reinforcing bar or the main reinforcing bar and the distributing bar. In the concrete,
6. The composite segment of claim 5, wherein a connecting rebar is provided connecting the inner rebar and the projecting plate. The connecting reinforcing bars are
The synthetic segment according to claim 6, wherein both ends are bent to form a U-shape, one end is hooked on the inner reinforcing bar, and the other end is inserted through the hole. In the concrete,
The composite segment according to claim 5, further comprising a connecting reinforcing bar that passes through the hole of the protruding plate and connects the inner reinforcing bar and the outer reinforcing bar. The connecting reinforcing bars are
9. The synthetic segment according to claim 8, wherein both ends are bent to form a U-shape, one end is hooked on the inner reinforcing bar, and the other end is hooked on the outer reinforcing bar. The projecting plate is
A synthetic segment according to any preceding claim, provided on the skin plate. The projecting plate is
A composite segment according to any one of claims 1 to 9, provided on the main girder. An earth retaining structure formed by combining a plurality of composite segments according to any one of claims 1 to 11 in the circumferential direction and the axial direction.

Images