JP2008144504A - Concrete anchoring member for composite segment and composite segment using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily manufacturable concrete anchoring member for a composite segment and the composite segment using it simply attachable to a steel member (a skin plate), achieving excellent anchoring effect of concrete securely, and reducing anchoring costs. <P>SOLUTION: This member for enhancing the property for anchoring concrete 20 on the skin plate 4 is composed of a plurality of vertical reinforcing bars 7 arranged at a predetermined interval and horizontal reinforcing bars 8 arranged on these vertical reinforcing bars 7 at a predetermined interval by crossing them orthogonally and by joining crossing points of both of the reinforcing bars by welding and is constituted by netted reinforcing bars 6 joined with the skin plate 4 by welding. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a concrete fixing member of a composite segment that constructs a tunnel wall by connecting in a circumferential direction and an axial direction of the tunnel, and a composite segment using the same.

The synthetic segment that constructs the tunnel wall is made of steel and concrete, and is resisted by protrusions (fixing material) provided on the steel to prevent the steel and concrete from peeling off and fix.
Such a fixing material is welded to steel and embedded in concrete to exert a fixing effect, but this fixing effect is related to the amount of welding to the steel and the surface area of the fixing material. It is necessary to increase the surface area of the fixing material relative to the welding area.

  There is a conventional synthetic segment in which a large number of bolt-shaped studs are provided by welding on the inner surface side (the side on which concrete is placed) of the skin plate constituting the synthetic segment as a fixing material. Some skin plates have protrusions as fixing materials on the inner surface thereof (see, for example, Patent Document 1).

JP-A-5-163894 (page 3, FIG. 3, FIG. 4)

In the synthetic segment as shown in FIG. 3 of Patent Document 1, a large number of studs must be welded and joined to the skin plate one by one. There was a problem.
Further, as shown in FIG. 4 of Patent Document 1, when using a skin plate (steel plate with protrusions) provided with protrusions, not only is the steel material expensive, but generally, the steel sheet with protrusions can be used because the protrusions are low. There was a problem that the range was limited.
Furthermore, in any case, since the surface area is small, the concrete is not sufficiently fixed, and there is a risk of peeling from the skin plate.

  The present invention has been made to solve the above-described problems, and is easy to manufacture, easy to attach to a steel material (skin plate), can reliably exhibit the effect of fixing concrete, and cost. It is an object of the present invention to provide a concrete fixing member having a synthetic segment that can reduce the above-mentioned and a synthetic segment using the same.

  The concrete fixing member of the composite segment according to the present invention is a member that is provided on the inner surface side of the skin plate that constitutes either or both of the outer peripheral side and the inner peripheral side, and is a member for enhancing the fixing of the concrete to the skin plate. And this member is comprised with the mesh reinforcement.

  Moreover, the concrete fixing member of the composite segment according to the present invention is provided on the inner surface side of the skin plate that constitutes either or both of the outer peripheral side and the inner peripheral side, and enhances the concrete fixing to the skin plate. A plurality of vertical reinforcing bars arranged at predetermined intervals, and arranged above and below these vertical reinforcing bars at predetermined intervals and perpendicularly, and the intersections of the two are welded and joined. It consists of horizontal reinforcing bars and is composed of mesh reinforcing bars welded to the skin plate.

Reinforcing bars having an outer diameter of 3 to 10 mm were used for the vertical reinforcing bars and the horizontal reinforcing bars that form the above-described net reinforcing bars.
Moreover, the space | interval of the vertical reinforcement and horizontal reinforcement which form said mesh reinforcement was 50-150 mm.
Furthermore, a plurality of tangled bars were provided on the above-mentioned rebar.

Supporting legs were provided on the above-mentioned rebar, and the rebar was held at a predetermined height from the skin plate.
In addition, a U-shaped or wavy support leg is attached to the lower surface of the above-described rebar, and the support leg is welded to the skin plate.

The composite segment according to the present invention includes a pair of axial walls, a skin plate joined to either or both of the outer peripheral side and the inner peripheral side of the axial wall, and both ends of the axial wall and the skin plate. Concrete is cast in a region formed by the joined circumferential walls, and the concrete fixing member according to any one of claims 1 to 7 is provided on the inner surface side of the skin plate.
In addition, a high-fluidity concrete having a maximum aggregate size of 20 mm, a slump flow of 60 cm ± 10 cm, and an air amount of 2% ± 1% was used as the concrete.
Moreover, said axial direction wall was comprised with the steel pipe or the concrete filling steel pipe.

  According to the present invention, a highly reliable synthetic segment that is easy to manufacture and can be easily attached to a steel material (skin plate), can reliably exert a concrete fixing effect, and can reduce costs. A concrete fixing member and a composite segment using the same can be obtained.

[Embodiment 1]
1 is an explanatory diagram of a composite segment according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of FIG.
In both figures, 1 is a synthetic segment, a pair of axial walls 2a and 2b made of a steel plate 3 formed in an arc shape along the circumferential direction of the tunnel, and a steel plate welded to the outer peripheral side of the axial wall. And a circumferential fixing wall 5a, 5b welded to both end portions of the axial plates 2a, 2b and the skin plate 3, and a concrete fixing member made of a rebar on the inner surface side of the skin plate 4. 6 is provided integrally.

  Reference numeral 20 denotes concrete placed in a box-shaped region surrounded by the axial walls 2a and 2b, the skin plate 4 and the circumferential walls 5a and 5b, but the concrete 20 is omitted in FIG. Although not shown, a skin plate or a steel bar may be provided between the two axial walls 2a and 2b at a predetermined interval to maintain the interval between them and to reinforce them. In order to prevent 20 cracks and the like, a plurality of reinforcing bars may be arranged in the longitudinal direction (circumferential direction) and the width direction (axial direction).

As shown in FIG. 3, the rebar which constitutes the concrete fixing member 6 is slightly shorter than the length of the skin plate 4 in the longitudinal direction (circumferential direction), and the width direction (axis) Direction) and a plurality of reinforcing bars 7 (hereinafter referred to as vertical reinforcing bars) arranged at a predetermined interval S ₁ , and slightly shorter than the axial width of the skin plate 4 and perpendicular to the vertical reinforcing bars 7. a plurality of reinforcing bars 8 arranged at intervals S ₂ (hereinafter, referred to as transverse reinforcing bar) becomes from a, it is obtained by forming a network by welding the intersection of the two.

  In the embodiment, reinforcing bars having an outer diameter of 6 mm are used for the vertical reinforcing bars 7 and the horizontal reinforcing bars 8. However, the outer diameters of the reinforcing bars 7 and 8 are appropriately selected according to the size and structure of the composite segment 1. However, since the skin plate 4 is generally a thin plate, the weld leg length of the rebar 6 is about 3 to 5 mm. It is desirable to use 8 having an outer diameter of about 6 to 8 mm.

In the embodiment, the spacing S ₁ of the longitudinal reinforcing bars 7, 100 mm both the spacing S ₂ of the horizontal reinforcing bar 8, therefore, although the size of the mesh was 100 × 100 mm, which is also of synthetic segments 1 size, It should be selected appropriately according to the structure, concrete 20 to be placed, etc. Generally, the interval S ₁ between the vertical bars 7 and the interval S ₂ between the horizontal bars 8 is about 50 to 150 mm, preferably about 80 to 120 mm. It is. In addition, the space | interval of both the reinforcing bars 7 and 8 does not necessarily need to be equal, and the mesh formed by this may be a rectangle.

  As shown in FIG. 3, the rebar 6 configured as described above is placed on the skin plate 4 with the vertical rebar 7 facing downward, and a plurality of longitudinal bars of each vertical rebar 7 are placed on the skin plate 4. Each is welded and integrated. Although the figure shows the case where the vertical rebar 7 is joined to the skin plate 4 with the vertical rebar 7 facing down, it is placed on the skin plate 4 with the horizontal rebar 8 facing down, and the horizontal rebar 8 is welded to the skin plate 4. May be.

  As shown in FIGS. 1 and 2, the skin plate 4 is joined to the outer peripheral side of the axial walls 2a and 2b with the rebar 6 inside, and the circumferential walls 5a and 5b are joined to both ends thereof. Then, if the concrete 20 is placed in the box-shaped region formed by these, the composite segment 1 is completed. At this time, since the concrete 20 is reliably filled in the mesh of the rebar 6 and between the skin plate 4 and the horizontal rebar 8 (or the vertical rebar 7), the concrete 20 is firmly fixed to the skin plate 4.

FIG. 4 is a cross-sectional view of another example of the synthetic segment according to the present embodiment.
In the case of FIG. 1 and FIG. 2, the case where the skin plate 4 is joined to the outer peripheral side of the composite segment 1 and the concrete 20 is placed with the inner peripheral side opened is shown, but in FIG. The skin plate 4a provided with the rebar 6 on the inner surface side is welded to the inner peripheral side of the segment 1 as well. The skin plates 4 and 4a may be provided only on the inner peripheral side of the composite segment 1 (the same applies to other embodiments).
In this case, since the composite segment 1 has a closed cross section, when filling the concrete 20, first, a circumferential wall (for example, 5b) is joined to one end portion, and the concrete is introduced into the inside from the other opened end portion. After filling 20 and the concrete 20 is solidified, the circumferential wall 5a may be joined to the other end.

FIG. 4 (b) shows a substantially S-shape with a predetermined interval in the longitudinal direction on the rebar 6 provided on the outer skin plate 4 and the inner skin plate 4a in the composite segment 1 of FIG. 4 (a). A tangled muscle 9 is provided.
By the way, in the synthetic segment 1 according to the present embodiment, in particular, in the synthetic segment 1 as shown in FIG. 4, the concrete 20 is firmly fixed to the skin plate 4 (4 and 4a), and the bending strength and bending rigidity of the segment S are increased. In order to ensure the above, it is necessary that the concrete 20 is filled to every corner including the rebar 6. Therefore, in the present embodiment, high-fluidity concrete (hereinafter sometimes simply referred to as concrete) having a maximum aggregate size: 20 mm, slump flow: 60 cm ± 10 cm, and air amount: 2% ± 1% was used. As a result, it was possible to reliably fill the concrete 20 to every corner (the same applies to other embodiments).

According to the present embodiment configured as described above, the concrete fixing member 6 provided on the skin plates 4 and 4a (hereinafter simply referred to as 4) is configured by the net reinforcing bar. The welding joining to the plate 4 is easy, and the cost can be reduced.
Moreover, the height of the concrete fixing member can be arbitrarily set by changing the outer diameter of both or one of the vertical reinforcing bars 7 and the horizontal reinforcing bars 8 of the rebar 6.

  Further, the mesh rebar 6 has a large surface area, and the concrete 20 is filled in the mesh and between the skin plate 4 and the horizontal rebar 8 (or the vertical rebar 7). Yes, it will not peel off. Note that, as shown in FIG. 4B, if a tangled reinforcing bar 9 is provided between the outer and inner mesh rebars 6, the fixing property of the concrete 20 is further improved, and the concrete 20 is cracked. Can be prevented.

  Further, by providing the concrete fixing member 6 made of mesh rebar on the skin plate 4, it is possible to reliably secure the fixing property between the steel material and the concrete 20, thereby obtaining a synthetic segment that is easy to manufacture and highly reliable. Can do.

[Embodiment 2]
FIG. 5 is an explanatory diagram of a composite segment according to Embodiment 2 of the present invention, and FIG. 6 is a cross-sectional view taken along line BB in FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In Embodiment 1, although the case where the axial direction walls 2a and 2b of the synthetic segment 1 were formed with the steel plate 3 was shown, this Embodiment formed the axial direction walls 2a and 2b with the steel pipe 10 of a square cross section. It is.

  The steel pipe 10 constituting the axial walls 2a and 2b of the composite segment 1 according to the present embodiment is bent into an arc shape along the circumferential direction of the tunnel, filled with concrete 20 inside, and restrained at both ends thereof. The plates 11 are joined. Thereby, the steel pipe 10 and the concrete 20 are integrated, and the bending strength and bending rigidity of the steel pipe 10 can be improved.

  And between the outer peripheral surface of both the steel pipes 10 or the outer peripheral side of both the steel pipes 10, the skin plate 4 provided with the mesh reinforcement 6 which is the concrete fixing member described in FIG. The circumferential walls 5a and 5b are joined, and the concrete 20 is placed in a region surrounded by these. In this case, the horizontal reinforcing bar 8 of the mesh reinforcing bar 6 is formed to be slightly shorter than the width of the region where the concrete 20 is placed, and hence the distance between the steel pipes 10. The steel pipe 10 may be formed by welding the end of a steel plate to form a square cross section.

  Also in the present embodiment, as shown in FIG. 4 of the first embodiment, a skin plate 4 a provided with a rebar 6 on the inner surface side may be joined to the inner peripheral side of the composite segment 1, A tangled bar 9 may be provided on the rebar 6 of the skin plates 4 and 4a. The constraining plates 11 provided at both ends of the steel pipe 10 may be omitted, the openings may be closed with the circumferential walls 5a and 5b, and the steel pipe 10 may not be filled with the concrete 20 and may remain hollow. Good.

The synthetic segment 1 according to the present embodiment can obtain substantially the same effect as in the case of the first embodiment. However, since the axial walls 2a and 2b are formed of the steel pipe 10, the steel pipe 10 is buckled. Therefore, it is possible to ensure the rigidity capable of withstanding the load when placing the concrete 20 without providing reinforcing means.
Furthermore, since the support strength of the side surface of the synthetic segment 1 is improved, it is possible to withstand a large pushing force during construction, thereby reducing the manufacturing time of the synthetic segment 1 and improving the workability. .

[Embodiment 3]
In each of the above embodiments, the case where the vertical reinforcing bar 7 or the horizontal reinforcing bar 8 of the mesh reinforcing bar 6 as a concrete fixing member is directly welded and joined to the skin plate 4 is shown. In order to ensure the thickness, the rebar 6 is held at a predetermined height position with a gap from the skin plate 4.

In the present embodiment, for example, a plurality of support legs formed by bending steel bars into a U shape or a wave shape are welded to the lower surface of the rebar 6 so as to maintain a predetermined height, and this support is formed. The legs are welded to the skin plate 4 to secure a predetermined gap between the skin plate 4 and the rebar 6. Instead of providing the support legs, the rebar 6 may be formed by bending in the longitudinal direction or the width direction into a wave shape, a bellows shape, or the like, and a gap may be provided between the skin plate 4.
According to the present embodiment, since the concrete 20 is sufficiently and reliably filled between the skin plate 4 and the rebar 6, the fixing effect of the concrete 20 can be further enhanced.

  In the above description, the case where the concrete fixing member (reinforcing bar) 6 according to the present invention is used for the composite segment 1 according to the first and second embodiments is shown, but the present invention is not limited to this, and other structures are used. The concrete fixing member of the present invention can also be used for the synthetic segment.

It is explanatory drawing of the synthetic | combination segment which concerns on Embodiment 1 of this invention. It is AA sectional drawing of FIG. It is explanatory drawing of the concrete fixing member (mesh rebar) of FIG. It is sectional drawing of the other example of the synthetic | combination segment of FIG. It is explanatory drawing of the synthetic | combination segment which concerns on Embodiment 2 of this invention. It is BB sectional drawing of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Composite segment, 2a, 2b Axial wall, 3 Steel plate, 4, 4a Skin plate, 5a, 5b Circumferential wall, 6 Concrete fixing member (mesh rebar), 7 Vertical rebar, 8 Horizontal rebar, 9 Tangle rebar, 10 Steel pipe , 11 Restraint plate, 20 concrete.

Claims (10)

A member for increasing the fixation of concrete to the skin plate, provided on the inner surface side of the skin plate constituting both or one of the outer peripheral side and the inner peripheral side of the composite segment,
A composite fixing member for a composite segment, characterized in that the member is composed of a rebar. A member for increasing the fixation of concrete to the skin plate, provided on the inner surface side of the skin plate constituting both or one of the outer peripheral side and the inner peripheral side of the composite segment,
The member includes a plurality of vertical reinforcing bars arranged at predetermined intervals, and a horizontal reinforcing bar arranged above or below the vertical reinforcing bars at a predetermined interval and orthogonally, and an intersection of the two is weld-joined. A composite segment concrete fixing member comprising a mesh reinforcing bar welded to the skin plate.   3. The composite segment concrete fixing member according to claim 2, wherein a reinforcing bar having an outer diameter of 3 to 10 mm is used for the vertical reinforcing bar and the horizontal reinforcing bar forming the mesh reinforcing bar.   The concrete fixing member for a composite segment according to claim 2 or 3, wherein a distance between the vertical reinforcing bar and the horizontal reinforcing bar forming the mesh reinforcing bar is 50 to 150 mm.   The composite fixing member for a composite segment according to any one of claims 2 to 4, wherein a plurality of tangled bars are provided on the rebar.   3. A structure in which a support leg is provided on the mesh rebar instead of the mesh rebar that is welded to the skin plate, and the mesh rebar is held at a predetermined height from the skin plate. The concrete fixing member of the synthetic segment in any one of -5.   7. The composite segment concrete fixing member according to claim 6, wherein a U-shaped or corrugated support leg is attached to the lower surface of the rebar, and the support leg is welded to the skin plate. A pair of axial walls, a skin plate joined to one or both of the outer peripheral side and the inner peripheral side of the axial wall, and a circumferential wall joined to both ends of the axial wall and the skin plate. In the composite segment formed by placing concrete in the formed area,
A synthetic segment comprising the concrete fixing member according to claim 1 provided on an inner surface side of the skin plate.   9. The synthetic segment according to claim 8, wherein high-fluidity concrete having a maximum aggregate size of 20 mm, a slump flow of 60 cm ± 10 cm, and an air amount of 2% ± 1% is used as the concrete.   The synthetic segment according to claim 8 or 9, wherein the axial wall is formed of a steel pipe or a concrete-filled steel pipe.

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