JP2011012495A - Segment and segment joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a segment capable of securing fixing performance without increasing the size of a segment joint.SOLUTION: The segment 1 of a tunnel includes a skin plate 2 forming an outer peripheral surface of the tunnel, main girders 3, 3 erected at both side edges thereof at an interval in the axial direction, joint plates 4, 4 erected at both end edges of the skin plate at an interval in the peripheral direction, ribs 5, 5A extending between the main girders on a surface of the skin plate to be parallel to the joint plates, segment joints 7 arranged on the joint plates to connect the segment to the other one in the peripheral direction, ring joints 8 arranged at the main girders to connect the segment with the other one in the axial direction, and a concrete part 6. Each of the segment joints extends between a notch formed at the rib 5 erected near the joint plate and the joint plate, and includes a fixing part embedded in the concrete part.

Description

  The present invention relates to a segment used for a shield tunnel lining (outer shell), and a segment joint portion provided at an end of a segment in the circumferential direction of the tunnel.

  Conventionally, it is known to use a synthetic segment formed of steel and concrete when assembling a cylindrical tunnel lining by joining a plurality of arcuate plate-shaped segments in the circumferential direction. (See Patent Documents 1-4 and the like).

  This synthetic segment is a box-shaped steel plate that is placed on the natural ground and forms the outer peripheral surface of the tunnel, a steel plate that surrounds the skin plate, and a skin plate and a steel frame. And the concrete filled in the inner space formed in the above.

  Such synthetic segments can ensure higher rigidity than steel segments, reinforced concrete segments, etc., reducing the construction cost by reducing the tunnel excavation soil volume by reducing the lining thickness. The construction period can be shortened. Note that Patent Document 2 discloses a synthetic segment having excellent fire resistance.

JP 2003-27894 A JP 2007-297906 A JP 2005-351535 A JP 2007-277893 A

  On the other hand, if there is no joint structure with high connection strength so that the segments do not open even when a large moment or tensile load is applied to the tunnel due to a large earthquake, etc. There is a possibility that water leakage may occur inside or the lining may be damaged (see Patent Document 3).

  However, if the lining thickness is made thin as a synthetic segment, the binding force of the concrete covering the joint hardware tends to be weak, so in order to secure the necessary fixing force, the fixing length of the joint hardware is increased, It is necessary to increase the size, which is an impediment to reducing the weight of the segment.

  Accordingly, an object of the present invention is to provide a segment and a segment joint portion that can ensure fixing performance without increasing the size of the segment joint portion.

  In order to achieve the above object, a segment of the present invention is a segment that forms a tunnel outer shell by combining a plurality of segments, and a skin plate that forms the outer peripheral surface of the tunnel, and a distance in the axial direction of the tunnel. A main girder that is erected on both side edges of the skin plate, a joint surface part that is erected on both edges of the skin plate at intervals in the circumferential direction of the tunnel, and the parallel to the joint surface part Between the rib part extended between the main girder parts on the surface of the skin plate, the segment joint part provided in the joint surface part to perform the connection between the circumferential segments, and between the axial segments A tunnel is formed by filling a space surrounded by a ring joint provided in the main girder for connection and at least the skin plate, the main girder, and the joint surface. A concrete portion that forms an inner peripheral surface of the joint portion, and the segment joint portion is bridged between the notch portion formed in the rib portion and the joint surface portion that is erected in the vicinity of the joint surface portion, and the joint surface portion. It has a fixing part embedded in a concrete part.

  Here, the fixing unit may be configured to include a rectangular plate-shaped fixing plate unit and a protrusion protruding in a direction substantially orthogonal to the fixing plate unit.

  In addition, a spacer protruding to the inner peripheral surface side of the tunnel can be attached to the rib portion, and a reinforcing bar can be installed on the spacer to be embedded in the concrete portion.

  Further, the ring joint portion may include a tensile shear joint that can resist the tensile force in the axial direction of the tunnel, and a shear joint that can resist only the shear force in a direction orthogonal to the axial direction. it can.

Further, the segment joint portion of the present invention includes a skin plate that forms an outer peripheral surface of a tunnel, a main girder portion erected on both side edges of the skin plate in the axial direction of the tunnel, and the circumferential direction of the tunnel. A segment joint portion for connecting a segment having a joint surface portion standing on both ends of the skin plate in the circumferential direction;
The rib is extended between the main girder on the surface of the skin plate in parallel with the joint surface, and is spanned between the joint surface and at least the skin plate, the main girder, and the joint. A space surrounded by the surface portion and the rib portion is filled and fixed to the constrained concrete portion.

  The segment of the present invention configured as described above includes a skin plate, a main girder portion standing on the edge thereof, a joint surface portion, and a rib portion extending between the main girder portions on the skin plate surface, It is comprised by the concrete part with which the space formed by these is filled. In addition, the segment joint portion has a fixing portion that spans between a notch portion formed in a rib portion erected in the vicinity of the joint surface portion and the joint surface portion.

  For this reason, the concrete part around the fixing part is in a restrained state sandwiched between the rib part and the joint surface part, and the fixing performance of the fixing part can be improved. In other words, the adhesion force of the fixing part embedded in the constrained concrete is larger than that in the case of being embedded in concrete that is not constrained, so that the desired fixing performance can be ensured even if the fixing part is short. Can do.

  Further, the fixing performance of the segment joint portion can be further enhanced by forming the fixing portion by a rectangular plate-shaped fixing plate portion and a projection portion protruding in a direction substantially orthogonal thereto.

  Furthermore, a reinforcing bar can be easily installed in the desired position of a lining thickness direction by attaching a spacer to a rib part.

  Further, if the ring joint portion is constituted by a tensile shear combined joint that can resist the tensile force and a shear joint that can resist only the shearing force, for example, the tensile force generated in the axial direction of the tunnel during an earthquake The desired yield strength against the shearing force generated in the ring joint portion can be supplemented by reasonable members, and a segment having the desired yield strength can be manufactured economically. Furthermore, the generation | occurrence | production of concentrated stress can be suppressed by disperse | distributing the generation | occurrence | production location of stress.

It is explanatory drawing partially broken in order to demonstrate the structure of the segment of embodiment of this invention. It is the perspective view which looked at the segment from the outer peripheral surface side of the tunnel. It is the perspective view which looked at the segment from the inner peripheral surface side of the tunnel. It is the expansion perspective view seen from the inside of a segment in order to explain the composition around a segment joint part. It is explanatory drawing partially fractured | ruptured in order to demonstrate the structure of a segment joint part periphery. It is an expansion perspective view explaining the structure of the ring joint part periphery before joining. It is an expansion perspective view explaining the structure of the ring joint part periphery after joining.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1-3 is a perspective view illustrating the configuration of the segment 1 of the present embodiment. This segment 1 is an arc plate-like member, and a cylindrical lining (outer shell) of the tunnel is formed by combining a plurality of segments 1.

  Hereinafter, the direction in which the tunnel extends is referred to as the axial direction of the tunnel, the arc direction of the cylindrical tunnel is referred to as the circumferential direction of the tunnel, the ground side of the lining is referred to as the outer peripheral surface of the tunnel, and the inner side of the lining Is called the inner periphery of the tunnel.

  This segment 1 is erected on a skin plate 2 that forms a part of the outer peripheral surface of the tunnel, main girder portions 3 and 3 that are erected on both side edges of the skin plate 2, and both edge edges of the skin plate 2. Joint plates 4 and 4 as joint surface portions, rib portions 5 and 5A extending between the main beam portions 3 and 3 on the surface of the skin plate 2, and a concrete portion 6 filled in the interior are mainly used. It is a synthetic segment.

  The skin plate 2 is formed by bending a thin rectangular steel plate into a circular arc when viewed from the side. The skin plate 2 has a long side in the circumferential direction of the tunnel and a short side in the axial direction of the tunnel.

  An arcuate main girder 3 is erected along the side edge which is the long side of the skin plate 2. That is, the main beam portions 3 and 3 are erected in parallel with an interval in the axial direction of the tunnel.

  As shown in FIG. 5, the main girder 3 includes a pair of flanges 3a and 3a arranged in parallel on the outer peripheral surface side and the inner peripheral surface side of the tunnel, and a web 3b connecting the flanges 3a and 3a. Is formed into a substantially U-shaped cross-sectional view.

  The flanges 3a, 3a and the web 3b are formed of, for example, a strip-shaped steel plate, and are joined to each other by welding or the like with substantially orthogonal crossing. Further, the web 3b is joined so as to protrude slightly toward the inner peripheral surface side than the flange 3a on the inner peripheral surface side of the tunnel.

  Moreover, as shown in FIG. 1-3, the joint board 4 is along the edge used as the short side of the skin plate 2 so that it may connect between the edge parts of the main girder parts 3 and 3 of the circumferential direction of a tunnel. Established. The joint plate 4 is formed of, for example, a rectangular steel plate, and is joined to the end portions of the main girders 3 and 3 by welding or the like.

  The joint plate 4 is provided with a segment joint portion 7 as shown in FIG. The segment joint portion 7 includes an insertion fitting 71 and a receiving fitting 72. That is, the receiving plate 72 is attached to the joint plate 4 of another segment 1 connected to the segment 1 in the circumferential direction at a position facing the insertion fitting 71, and at the position facing the receiving fitting 72. An insertion fitting 71 is attached. Then, by inserting the insertion fitting 71 into the fitting 72, the circumferential connection between the two segments 1 and 1 is performed.

  As shown in FIGS. 4 and 5, the insertion fitting 71 is provided integrally with the insertion portion 71 b that protrudes to the outside of the segment 1 from the joint plate 4, and extends into the segment 1. A fixing plate portion 71a serving as a fixing portion, and a protrusion 71c serving as a fixing portion provided at an end of the fixing plate portion and projecting in a direction substantially orthogonal to the fixing plate portion 71a.

  As shown in FIGS. 4 and 5, the receiving bracket 72 is provided integrally with the receiving portion 72 b that opens toward the outside of the segment 1 in the joint plate 4 and extends into the segment 1. A fixing plate portion 72a serving as a fixing portion is provided, and a protrusion 72d serving as a fixing portion provided at an end of the fixing plate portion 72a and projecting in a direction substantially orthogonal to the fixing plate portion 72a.

  The insertion fitting 71 and the receiving fitting 72 can be manufactured by joining steel materials by welding. Moreover, you may shape | mold integrally as a casting.

  As shown in FIG. 5, the joint plate 4 is provided with an insertion port 72c communicating with the receiving portion 72b of the receiving metal 72, and the insertion portion 71b of the insertion metal 71 of the segment 1 connected to the insertion port 72c. When the segment 1 is moved in the axial direction of the tunnel, the insertion fitting 71 is fitted into the receiving fitting 72.

  Further, the rib portions 5, 5 </ b> A extend between the main beam portions 3, 3 in parallel with the joint plate 4. A plurality of the rib portions 5 and 5A are erected at intervals in the circumferential direction of the tunnel, and the rib portions 5 that are close to the joint plate 4 are used as rib portions 5 on both sides in the circumferential direction of the segment 1. Let the thing arrange | positioned between 5 be rib part 5A. Hereinafter, the configuration will be described focusing on the rib portion 5, and the details of the rib portion 5A having the same configuration will be omitted.

  As shown in FIG. 4, the rib portion 5 is formed of a rectangular steel plate, and is cut out so that the lower half near the center becomes a gate shape, and a communication hole 52 is formed between the rib portion 5 and the skin plate 2. The By this communication hole 52, concrete can be filled without being blocked by the rib portions 5 and 5A.

  Further, as shown in FIGS. 4 and 5, the rib portion 5 adjacent to the joint plate 4 has a groove-shaped cutout portion 51 at a position where the fixing plate portions 71 a and 72 a of the insertion fitting 71 and the receiving fitting 72 are bridged. , 51 are formed.

  By providing the notch 51, the insertion fitting 71 and the receiving fitting 72 can be bridged between the joint plate 4 and the rib portion 5 at an intermediate position in the lining thickness direction (tunnel radial direction) of the segment 1. it can.

  Further, the fixing plate portions 71a and 72a extending from the joint plate 4 side toward the inside of the segment 1 pass through the notch portion 51 of the rib portion 5 and project to the rib portion 5A side, so that the protruding portions 71c, 72d is disposed between the rib portions 5 and 5A.

  Furthermore, a spacer 62 protruding to the inner peripheral surface side of the tunnel is attached to the rib portions 5 and 5A. The spacer 62 can be manufactured by forming a reinforcing bar into an L shape or a U shape. The spacer 62 is fixed by welding its leg portions to the side surfaces of the rib portions 5 and 5A.

  And the reinforcing reinforcing bars 61 are arranged in a lattice shape on the spacers 62. As shown in FIG. 5, the reinforcing reinforcing bars 61 are arranged on the inner peripheral surface side of the tunnel inner peripheral surface side flange 3 a of the main girder portion 3. The arrangement position of the reinforcing bars 61,... In the lining thickness direction of the segment 1 is adjusted by the protruding amount of the spacers 62,.

  Further, as shown in FIG. 1, a cylindrical holding metal 11 is erected at the center of the segment 1. The gripping hardware 11 is used as a gripping part that is gripped by an erector apparatus or the like when the segment 1 is transported and installed.

  Further, an adhesive (not shown) is applied to the surface of the flange 3a of the main girder 3 facing the reinforcing reinforcing bars 61,. This adhesive is applied in order to ensure adhesion with the concrete filled on the surface of the flange 3a, and an epoxy resin adhesive or the like can be used.

  Further, the concrete portion 6 has a box-shaped space formed by the skin plate 2 and the main girder portions 3 and 3 and the joint plates 4 and 4 erected on the edge thereof, and reinforcing steel bars 61 and so on. It is formed by filling concrete up to the buried position.

  Here, as shown in FIGS. 2 and 3, the concrete portion 6 formed in a layered manner on the inner circumferential surface side of the tunnel than the main girder portion 3 is a fire-resistant margin portion 6 a, and the heat generated inside the tunnel is The thickness is set so as to prevent transmission to the steel main girder 3.

  Moreover, the concrete part 6 can be shape | molded with the concrete with high fireproof performance in which synthetic resin fiber, such as a polypropylene fiber or a vinylon fiber, was mixed.

  Further, when filling concrete, the outer periphery of the segment 1 is surrounded by a rigid formwork device (not shown) so that distortion and deformation are not caused by the filling pressure of the concrete. In addition, by providing the formwork apparatus with a vibrator, the concrete filling performance is improved, and a dense concrete portion 6 can be formed.

  Next, a detailed configuration of the ring joint portion 8 serving as a joint in the tunnel axial direction of the segment 1 will be described with reference to FIGS.

  This ring joint portion 8 includes a tensile shear joint 81 capable of resisting a tensile force in the tunnel axial direction and a shearing force orthogonal to the tunnel radial direction (tunnel inner and outer directions), and a shear capable of resisting only the shearing force. And a joint 82. The number of shear joints 82 can be reduced or omitted when the shearing force assumed at the time of design is small.

  The tensile shear joint 81 is composed of a press fitting 811 provided on one segment 1A side and a press fit receiver 812 provided on the other segment 1B side.

  The press fitting 811 includes a press fitting pin portion 811 a that protrudes from the web 3 b of the main girder portion 3 and a fixing portion 811 b that is embedded in the segment 1. In addition, the press-fitting metal fitting 812 includes an insert part 812a that becomes resistance to a pulling force when the press-fitting pin part 811a of the press-fitting metal part 811 is pushed in, and a fixing part 812b that extends rearward.

  Furthermore, the shear joint 82 includes a pin hardware 82a provided on the one segment 1A side and a pin receiving hardware 82b provided on the other segment 1B side.

  When this ring joint portion 8 is connected, first, as shown in FIG. 6, the ring joint portion 8 of the other segment 1B is opposed to the ring joint portion 8 of one segment 1A, and the segment 1B is connected to the shaft of the tunnel. The webs 3b and 3b of the segments 1A and 1B are brought into contact with each other by moving in the direction.

  When the webs 3b and 3b come into contact with each other, as shown in FIGS. 6 and 7, the press-fit pin portion 811a protruding from the web 3b of the press-fit metal 811 is pushed into the insert portion 812a of the press-fit metal 812 facing each other. . On the other hand, the portion of the pin hardware 82a protruding from the web 3b is also inserted into the pin receiving hardware 82b facing each other. Accordingly, the segments 1A and 1B are connected by the ring joint portions 8 and 8.

  Next, the operation of the segment 1 and the segment joint portion 7 of the present embodiment will be described.

  The segment 1 of the present embodiment configured as described above includes the skin plate 2, the main girders 3 and 3 erected on the edge thereof, the joint plates 4 and 4, and the main girder on the skin plate 2 surface. It is manufactured as a synthetic segment by the rib portions 5 and 5A extending between the portions 3 and 3 and the concrete portion 6 filled in the space formed by these. Since such a synthetic segment can be easily designed to optimize the cross section of the steel material, the manufacturing cost of the segment 1 can be reduced.

  Further, the segment joint portion 7 constituting the joint in the circumferential direction of the tunnel has fixing plate portions 71 a and 72 a that are spanned between the notch portion 51 formed in the rib portion 5 adjacent to the joint plate 4 and the joint plate 4. is doing.

  For this reason, the concrete portion 6 around the fixing plate portions 71a and 72a is in a restrained state sandwiched between the rib portion 5 and the joint plate 4, and the fixing performance of the fixing plate portions 71a and 72a can be improved.

  That is, the adhesion force of the fixing plate portions 71a and 72a embedded in the constrained concrete is larger than that in the case where the fixing plate portions 71a and 72a are embedded in the non-restrained concrete. Desired fixing performance can be ensured. For this reason, it can prevent that the insertion metal fitting 71 and the receiving metal fitting 72 enlarge, and the weight of the segment 1 increases or a manufacturing cost increases.

  Further, the fixing portion is formed by the rectangular plate-like fixing plate portions 71a and 72a and the projection portions 71c and 72d protruding in a direction substantially orthogonal thereto, thereby further improving the fixing performance of the segment joint portion 7. it can.

  Furthermore, by providing the notch portion 51 in the rib portion 5, the lengths of the fixing plate portions 71a and 72a can be set regardless of the distance between the rib portion 5 and the joint plate 4. Further, since the rib portion 5 can be provided regardless of the lengths of the fixing plate portions 71a and 72a, the rib portion 5 can be erected and reinforced in the vicinity of the joint plate 4 where stress is easily concentrated.

  Further, by attaching a plurality of spacers 62,... To the rib portions 5, 5A, the reinforcing bars 61,... Can be easily installed at desired positions. For example, the arrangement position of the segment 1 in the lining thickness direction differs between the case where the reinforcing reinforcing bars 61, ... are arranged as crack preventing reinforcing bars and the case where the reinforcing reinforcing bars 61 are arranged as tensile reinforcing reinforcing bars on the inner peripheral surface side of the tunnel. However, by adjusting the protruding amount of the spacers 62,..., The reinforcing bars 61,.

  Further, if the reinforcing bars 61,... Are separated from the flange 3a on the inner peripheral surface side of the tunnel of the main girder part 3 using the spacers 62,..., The reinforcing bars 61,. Concrete is filled in between, and the adhesion of the refractory allowance portion 6a can be increased. Furthermore, by applying an adhesive to the flange 3a, the adhesion between the fireproof margin 6a and the main girder 3 is increased, and peeling can be prevented.

  In addition, by providing the fire-resistant margin part 6a or molding the concrete part 6 with high fire-resistant concrete mixed with synthetic resin fibers, the installation work of the fire-resistant plate can be omitted, and the construction period and cost are reduced. be able to.

  Further, the ring joint portion 8 is composed of a tensile shear joint 81 capable of resisting a tensile force in the tunnel axial direction, and a shear joint 82 capable of resisting only a shear force in an axial orthogonal direction such as a radial direction or a circumferential direction of the tunnel. If it comprises, the desired joint yield strength can be supplemented with a rational member, and the segment 1 of the desired yield strength can be manufactured economically.

  That is, when examining the direction perpendicular to the axis of the tunnel for seismic performance, since the shearing force acts predominantly on the ring joint portion 8, the resistance member of the tensile force compared to the shearing resistance member May be reduced. Even in such a case, if the ring joint portion 8 is configured only by the tensile shear joint 81, the manufacturing cost increases. However, the cost can be reduced by using a rational joint configuration for the desired strength. Can be reduced.

  Furthermore, if the ring joint portion 8 is composed of a plurality of members, the locations where the stress is generated are dispersed, so that the concentrated stress in the main girder portion 3 can be suppressed.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are not limited to this embodiment. Included in the invention.

  For example, in the above-described embodiment, the main girder 3 is formed into a substantially U-shaped cross-sectional view by the pair of flanges 3a, 3a and the web 3b in parallel, but is not limited to this, and the design cross-sectional force is small. In this case, either one of the flanges 3a and 3a can be omitted, or only the plate-like web 3b can be used to reduce the manufacturing cost.

  Moreover, although the said embodiment demonstrated the case where the fireproof allowance part 6a which covers the flange 3a by the side of a tunnel inner peripheral surface was provided, it is not limited to this. Further, the joint surface portion may not be the joint plate 4 but may be a member having an L shape in cross section or a U shape in cross section.

  Furthermore, in the said embodiment, although the concrete part 6 was formed over the whole segment 1, it is not limited to this, With the skin plate 2, the main girder parts 3, 3, and the joint plates 4, 4, In the segment having sufficient strength, it is not necessary to fill the entire surface of the skin plate 2 with concrete, and it extends close to the skin plate 2, the main girders 3, 3, the joint plate 4, and the joint plate 4. Concrete may be filled only in a space surrounded by the rib portion 5 formed.

  In the above embodiment, the projections 71c and 72d of the insertion fitting 71 and the receiving fitting 72 are provided at the ends of the fixing plate portions 71a and 72a. However, the present invention is not limited to this. It can also be provided in the middle of 72a.

  Furthermore, in the above-described embodiment, the one-touch type tensile shear combined joint 81 is described in which the connection is completed simply by pressing the press-fit metal 811 into the press-fit metal 812. However, the present invention is not limited to this. The joint may be a tensile shear combined joint in which a screw metal is provided on the 1A side, a screw receiving metal is provided on the other segment 1B side, and the tip of the screw metal is screwed into a nut portion of the screw receiving metal.

1, 1A, 1B Segment 2 Skin plate 3 Main girder 4 Joint plate (joint surface)
5,5A Rib portion 51 Notch portion 6 Concrete portion 62 Spacer 7 Segment joint portion 71 Insertion fitting 71a Fixing plate portion (fixing portion)
71c Protrusion 72 Receptacle 72a Fixing plate (fixing part)
72d Protrusion part 8 Ring joint part 81 Tensile shear joint 82 Shear joint

Claims (5)

A segment that forms the outer shell of a tunnel by combining a plurality,
A skin plate that forms the outer peripheral surface of the tunnel;
A main girder erected on both side edges of the skin plate at an interval in the axial direction of the tunnel;
A joint surface portion erected on both edges of the skin plate at intervals in the circumferential direction of the tunnel;
A rib portion extending between the main beam portions on the surface of the skin plate in parallel with the joint surface portion;
A segment joint portion provided on the joint surface portion to connect the segments in the circumferential direction;
A ring joint provided in the main girder for connecting the axial segments;
A concrete portion that fills a space surrounded by at least the skin plate, the main girder portion, and the joint surface portion and forms an inner peripheral surface of the tunnel;
The segment joint portion includes a notch portion formed in the rib portion erected in the vicinity of the joint surface portion and a fixing portion that is bridged between the joint surface portion and embedded in the concrete portion. And a segment.   The segment according to claim 1, wherein the fixing portion includes a rectangular plate-shaped fixing plate portion and a protruding portion that protrudes in a direction substantially orthogonal to the fixing plate portion.   The said rib part is attached with the spacer which protrudes in the inner peripheral surface side of the said tunnel, and installs a reinforcing bar in the said spacer, It is made to embed | buy in the said concrete part. segment.   The ring joint portion includes a tensile shear combined joint capable of resisting a tensile force in an axial direction of a tunnel, and a shear joint capable of resisting only a shear force in a direction orthogonal to the axial direction. The segment according to any one of 1 to 3. A skin plate that forms the outer peripheral surface of the tunnel, a main girder that is erected on both side edges of the skin plate in the axial direction of the tunnel, and erected on both edges of the skin plate in the circumferential direction of the tunnel A segment joint portion for connecting a segment having a joint surface portion in the circumferential direction,
The rib is extended between the main girder on the surface of the skin plate in parallel with the joint surface, and is spanned between the joint surface and at least the skin plate, the main girder, and the joint. A segment joint part, which is filled in a space surrounded by a surface part and the rib part and is fixed to a concrete part in a restrained state.

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