JP2020016024A - Composite segment - Google Patents

Abstract

To provide a composite segment comprising a main steel material having a reasonable and economical structure.SOLUTION: A composite segment for constructing a tunnel lining in the underground includes a long main steel material extending in a tunnel circumferential direction, and an SRC structure segment main body in which the main steel material is embedded. The main steel material has a pair of arc-shaped steel plates installed at intervals in a member thickness direction of the segment main body, and a connection member for connecting the pair of arc-shaped steel plates. The connection member includes a concrete bearing surface facing the tunnel circumferential direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a composite segment that forms a lining.

  When constructing a shield tunnel, a cylindrical lining is constructed by assembling a plurality of segments on the wall of the ground excavated by a shield machine. The segment constituting this lining body is formed in a block having an arc-shaped curved surface obtained by dividing a cylindrical body into a plurality along a circumference and an axial direction, and particularly, as a segment for a large-section tunnel. The steel reinforced concrete structure (hereinafter, referred to as “SRC structure”) using steel as a main steel material extending in the circumferential direction is widely known.

  The main steel material constituting the segment of the SRC structure generally employs a steel material having a gap in the web portion. For example, in Patent Document 1, flat steel beams along the tunnel circumferential direction are paired in the thickness direction of the segment. They are arranged and connected by a lattice material made of a plurality of steel plates arranged with a predetermined spacing therebetween.

JP-A-4-228800

  When the tunnel is constructed on a soft ground or the like where the independence of the ground is low, as shown in FIG. 5, the SRC-constructed segment adds a load to the lining body 50 in addition to a reaction force due to its own weight and a groundwater pressure. Thus, a load P such as an earth pressure acts. For this reason, bending deformation occurs in the segment 51, and a compressive force in the tunnel circumferential direction is applied to the flat steel beam 53 on the outer peripheral surface side of the pair of flat steel beams 53 A so-called positive bending in which a tensile force acts on the flat steel beam 54 in the tunnel circumferential direction occurs.

  At this time, the lattice member 55 made of a steel plate connecting the pair of flat steel beams 53 and 54 is arranged so that the plate surfaces face each other in the tunnel axis direction, and the pair of flat steel beams 53 and 54 is not deformed by shearing. Since the shear force between them is smoothly transmitted, the shear deformation is suppressed. In addition, stud dowels 56 are generally provided on the plate surfaces of the pair of flat steel beams 53 and 54, or irregular shapes are formed. The displacement of the contact surface between the concrete 54 and 54 is suppressed.

  However, the work of installing the stud dowel 56 on the flat steel beams 53 and 54 and forming the uneven shape requires a great deal of labor and tends to be expensive. On the other hand, it is expected that the load P acting on the lining body 50 will increase as the need for a large cross section and a deep tunnel increases, and higher strength is required for the main steel frame 52 constituting the segment 51. You.

  The present invention has been made in view of such a problem, and a main object of the present invention is to provide a composite segment including a main steel material having a reasonable and economical structure.

  In order to achieve the above object, a composite segment of the present invention is a composite segment constituting a lining body of a tunnel constructed underground, and includes a long main steel material extending in a circumferential direction of the tunnel, and a main steel material. And a pair of arc-shaped steel plates, wherein the main steel material is installed at intervals in a thickness direction of the segment body, and a connection for connecting the pair of arc-shaped steel plates. And the connecting member is provided with a concrete bearing surface facing in the circumferential direction of the tunnel.

  According to the above-described composite segment of the present invention, by providing the connecting member of the main steel material with the concrete bearing surface facing in the circumferential direction of the tunnel, the shearing force transmitting the shear force between the pair of arc-shaped steel plates to the connecting member is provided. In addition to the force transmission function, the function of preventing the gap between the arc-shaped steel plate and the concrete can be integrated. For this reason, the number of members constituting the main steel material is greatly reduced, and not only the ease of manufacture is increased, but also the cost can be significantly reduced, and a rational and economic structure can be obtained.

  The composite segment of the present invention is characterized in that a plurality of shaped steel members are used for the connecting member.

  According to the above-described synthetic segment of the present invention, since a shaped steel that is handled in the general market is used as a connecting member, there is no need to newly manufacture a dedicated member, so that the manufacturing cost is increased while increasing the rigidity of the main steel material. It is possible to further reduce.

  In the synthetic segment of the present invention, the section steel is made of a channel steel, and the channel steel is provided with a plurality of gaps in the longitudinal direction of the arc-shaped steel sheet in a manner in which the plate surfaces of the flanges face each other in the circumferential direction of the tunnel. The release portions of the adjacent channel steels are arranged alternately in the forward and reverse directions of the tunnel axis direction.

  According to the above-described composite segment of the present invention, the plurality of channel steels are arranged so that the plate surface of the flange is a concrete bearing surface and the open portions between the flanges are alternately oriented in the forward and reverse directions of the tunnel axis direction. Therefore, even when a plurality of channel steels are employed as the connecting member, rigidity balance can be ensured, and local buckling of the channel steel, which is supported by concrete, can be suppressed.

  According to the present invention, for the connecting member of the main steel material, the shear force transmission function of transmitting the shear force between the pair of arc-shaped steel plates and the function of preventing the gap between the arc-shaped flat steel plate and the concrete can be aggregated, Not only does the number of components that make up the main steel material be significantly reduced, making it easier to manufacture, but also significantly reduces costs, making the composite segment with the main steel material a reasonable and economical structure. It becomes possible.

FIG. 3 is a diagram schematically illustrating a synthesis segment according to the embodiment of the present invention. It is a figure showing the side of a synthetic segment in an embodiment of the invention. It is a figure showing the plane of the main steel material in an embodiment of the invention. It is a figure showing other examples of the main steel material in an embodiment of the invention. It is a figure which shows the outline of the conventional synthetic segment.

  The composite segment of the present invention will be described in detail below with reference to FIGS.

  As shown in FIG. 1, the synthetic segment 10 is assembled along a tunnel circumferential direction and a tunnel axial direction to construct a cylindrical lining body on a wall surface of a ground excavated by a shield machine. An arc-shaped block comprising a segment main body 1 having an outer shape on an arc, and a joint member 5 installed at a circumferential end of the segment main body 1 in a tunnel circumferential direction and having a joint fitting and a joint plate. The joint member 5 may have any structure as long as it can be used for the segments constituting the lining body.

  As shown in the side view of FIG. 2, the segment body 1 is made of an SRC structure including concrete 4, a reinforcing cage 3 buried in the concrete 4, and a long main steel material 2 extending in the circumferential direction of the tunnel. The steel material 2 includes a pair of arc-shaped steel plates 21 and a connecting member 22 that connects the pair of arc-shaped steel plates 21.

  Each of the pair of arc-shaped steel plates 21 extends in the tunnel circumferential direction, is provided with a predetermined space provided with the plate surface facing the member thickness direction of the segment main body 1, and the connecting member 22 is disposed in this space. ing. The connecting member 22 is composed of a plurality of channel steels 23, and the channel steels 23 are arranged at intervals in the longitudinal direction of the arc-shaped steel plate 21.

  As shown in the plan view of the main steel material 2 in FIG. 3, the plurality of channel steels 23 are arranged such that the plate surface of the web 231 faces the tunnel axial direction and the plate surface of the flange 232 faces the tunnel circumferential direction. Is done. The open portions 233 formed between the pair of flanges 232 of the channel steel 23 are alternately oriented in the forward and reverse directions of the tunnel axis direction.

  As shown in FIG. 2, the composite segment 10 provided with the main steel material 2 having the above-described configuration, when a load P that causes bending deformation is applied from the outer peripheral surface side, is applied to the outer peripheral surface side of the segment body 1 in the tunnel circumferential direction. A so-called positive bending occurs in which a compressive force and a tensile force in the tunnel circumferential direction act on the inner peripheral surface side, respectively.

  Then, a shearing force acts on the contact surface between the arc-shaped steel plate 21 and the concrete 4 constituting the segment main body 1. However, the arc-shaped steel plate 21 has a plurality of grooves formed with the plate surfaces of the flanges 232 opposed in the tunnel circumferential direction. Steel 23 is installed. For this reason, the plate surface of the flange 232 acts as a bearing surface of the concrete 4 and resists a behavior in which the arc-shaped steel plate 21 and the concrete 4 tend to shift in the circumferential direction of the tunnel.

  Among the pair of arc-shaped steel plates 21, the arc-shaped steel plate 21 located on the outer peripheral surface side of the segment main body 1 receives a compressive force in the tunnel circumferential direction, and the arc-shaped steel plate 21 located on the inner peripheral surface side applies tensile force in the tunnel circumferential direction. Positive bending occurs in which forces are applied, and shear force is transmitted to each of the plurality of channel steels 23. However, since the channel steel 23 is stiffened by the concrete 4 in contact with the front and back surfaces of the flange 232, the shear force between the pair of arc-shaped steel plates 21 can be smoothly transmitted without causing shear deformation. .

  According to the synthetic segment 10 of the present invention, the connecting member 22 of the main steel material 2 is constituted by a plurality of channel steels 23, and the flanges 232 of the channel steels 23 are arranged such that the plate surfaces face each other in the circumferential direction of the tunnel. Since the bearing surface is used, the shearing force transmitting function of transmitting the shearing force between the pair of arc-shaped steel plates 21 and the function of preventing the displacement between the arc-shaped steel plate 21 and the concrete 4 can be concentrated on the connecting member 22. . For this reason, the number of members constituting the main steel material 2 is greatly reduced, and not only the ease of manufacture is increased, but also the cost can be significantly reduced, and a rational and economical structure can be achieved.

  Further, since the plurality of channel steels 23 are arranged so that the open portions 233 between the flanges 232 are alternately oriented in the forward and reverse directions of the tunnel axis direction, the plurality of channel steels 23 are employed as the connecting member 22. In this case as well, the rigidity balance of the main steel material 2 can be ensured, and the local buckling of the channel steel 23 which is supported by the concrete 4 can be suppressed.

  The composite segment 10 of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  In the present embodiment, when adopting a plurality of channel steels 23 as the connecting members 22 constituting the main steel material 2, these channel steels 23 are arranged on the axis C of the arc-shaped steel plate 21 as shown in FIG. 3. . However, as shown in FIG. 4A, the arc-shaped steel plates 21 may be arranged in a staggered manner with a predetermined amount of displacement in the tunnel axis direction with the axis C interposed therebetween.

  Further, in the present embodiment, a plurality of channel steels 23 are employed as the connecting members 22 constituting the main steel material 2, but the present invention is not limited to this. For example, as shown in FIG. 4 (b), any shaped steel having a surface capable of functioning as a concrete bearing surface, such as an H-shaped steel 24, may be used. The quantity may be any. As described above, when the connecting members 22 are shaped steels such as the channel steel 23 and the H-shaped steel 24 which are handled in the general market, there is no need to newly manufacture a dedicated member, and the rigidity of the main steel material 2 is increased. However, the manufacturing cost can be further reduced.

  Further, in the present embodiment, only two main steel materials 2 are arranged in the segment main body 1 in the tunnel axial direction, but the number is not limited to this.

DESCRIPTION OF SYMBOLS 10 Synthetic segment 1 Segment main body 2 Main steel material 21 Arc-shaped steel plate 22 Connecting member 23 Channel steel 231 Web 232 Flange 233 Opening 24 H-shaped steel 3 Reinforcing cage 4 Concrete 5 Joint member

Reference Signs List 50 lining body 51 segment 52 main steel frame 53 flat steel beam 54 flat steel beam 55 lattice material 56 stud dowel 57 concrete

Claims (3)

A synthetic segment comprising a tunnel lining constructed underground,
A long main steel material extending in the circumferential direction of the tunnel;
An SRC-structured segment body in which the main steel material is embedded,
The main steel material has a pair of arc-shaped steel plates that are installed with an interval in a member thickness direction of the segment main body, and a connecting member that connects the pair of arc-shaped steel plates,
The composite segment includes a concrete bearing surface facing in the circumferential direction of the tunnel. In the synthetic segment of claim 1,
A composite segment wherein a plurality of shaped steel members are used for the connecting member. In the synthetic segment according to claim 2,
The section steel is made of a channel steel,
A plurality of the channel steels are arranged in parallel at intervals in the longitudinal direction of the arc-shaped steel plate in such a manner that the plate surfaces of the flanges face each other in the tunnel circumferential direction, and the release portions of the adjacent channel steels are provided. A composite segment characterized by being alternately oriented in the forward and reverse directions of the tunnel axis.

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