JP4125635B2 - segment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a segment used for primary lining of a tunnel excavation cross section.
[0002]
[Prior art]
When constructing various tunnels such as shield tunnels, segments such as RC structures and steel structures are used as covering bodies for excavation surfaces. For example, as disclosed in Patent Document 1, this type of segment is usually manufactured in advance as a segment piece obtained by dividing a cylindrical body into a plurality of portions in the circumferential and axial directions.
[0003]
FIG. 6 shows a detailed internal structure example of the segment piece used for such an application. The segment piece shown in the figure has a segment piece main body 1 formed in a curved plate shape obtained by dividing a cylinder into a plurality of pieces along an axis and a circumferential direction.
[0004]
The segment piece main body 1 is formed into a curved plate shape by placing concrete, and includes an upper surface 2 and a lower surface 3 arranged in parallel to each other in the vertical direction, and a pair of surfaces provided on both side ends in the longitudinal direction are pieces. A pair of surfaces provided on both side ends in the short direction are the inter-ring joint surfaces.
[0005]
One end of a joint fitting 6 used when connecting adjacent joint surfaces 4 is embedded in the joint surface 4 between pieces so as to face the joint surface 4, and anchor bars 9 are connected to the joint fitting 6. Has been. A plurality of main bars 7 and distribution bars 8 are embedded in the segment piece body 1.
[0006]
In the example shown in FIG. 6, the main bars 7 are arranged in two stages so as to bend along the upper and lower surfaces 2, 3, and such main bars 7 are arranged at predetermined intervals in the short direction of the segment piece 1. A plurality are arranged with a gap therebetween.
[0007]
Between the pair of main muscles 7 arranged in the vertical direction, both ends of the power distribution muscle 8 are locked so as to be orthogonal to the longitudinal direction of the main muscle 7. Are provided at predetermined intervals.
[0008]
However, the segment piece having such a structure has a technical problem described below.
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-229788
[Problems to be solved by the invention]
That is, in the segment piece shown in FIG. 6, the stress generated in the joint fitting 6 having one end exposed at the inter-ring joint surface 4 is transmitted to the main bar 7 via the anchor bar 9.
[0011]
However, since the anchor bar 9 and the main bar 7 have a lap joint structure, this stress transmission is caused by one joint fitting 6 → anchor bar 9 → concrete of the main body 1 → main bar 7 → concrete of the main body 1 → anchor bar. 9 → transmitted to the other joint fitting 6, especially when concrete is interposed between the anchor bar 9 and the main bar 7 and there is no direct relationship between the two, so when the segment piece is assembled in an annular shape Stress transmission could not be performed smoothly.
[0012]
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a segment capable of smoothly transmitting stress.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is composed of a plurality of curved plate-like segment pieces having a pair of pieces and an inter-ring joining surface, and tunnel excavation so that the inter-piece joining surfaces are joined to each other. Adjacently arranged along the circumferential direction of the surface, the adjacent segment pieces are interconnected to assemble a ring body, and as the excavation progresses, the inter-ring joint surfaces are joined to each other. In a segment constructed by installing ring bodies adjacent to each other along the tunnel axis direction and connecting adjacent ring bodies to each other in a tubular shape inside the tunnel excavation surface, the segment piece is made of concrete. a curved plate segment piece body formed by a main reinforcement which is embedded in the segment piece body, one end side so as to face the joint surface between the pieces, the segment A joint fitting being embedded in Ntopisu body, both ends so as to respectively joined to said joint fitting and the main reinforcement, and a connecting metal fitting is embedded in the segment piece body, the connecting fitting, the A flat main bar mount in which the end of the main bar is fitted and arranged, and a plurality of connecting rods formed in a substantially concave shape, wherein the main bar mount includes an upper plate, a lower plate, and a space between these plates. Each of the connecting rods has a concave base end side fixed in the insertion hole of the joint fitting, and a pair of other end sides fixed to the upper and lower plates, respectively. Set up .
[0014]
According to the segment configured as described above, the segment piece is formed by placing concrete so that a curved plate-shaped segment piece main body, a main bar embedded in the segment piece main body, and one end face the joint surface between the pieces. Since it has a joint fitting embedded in the segment piece body and a connection fitting embedded in the segment piece body so that both ends are joined to the main bar and the joint fitting respectively, it is connected from the joint bracket. The stress can be transmitted directly to the main muscle through the metal fitting, and the cost of the anchor can be reduced by omitting the anchor and the distribution bar.
[0015]
In this way, when the main reinforcement and the joint fitting are directly connected by the connecting fitting, when considering a circular cross section in which the segment pieces are assembled in an annular shape, the main reinforcement is connected in a ring shape, and the flow of stress as a circular pipe becomes smooth, It becomes a rational structure.
[0018]
The segment piece body can be formed of fiber-reinforced high-fluidity concrete.
[0019]
The fiber reinforcement of the high fluidity concrete can be composed of steel fibers.
The steel fiber is a short fiber having a length of 20 to 60 mm, a diameter of 0.3 to 0.9 mm, and an aspect ratio of 30 to 100, and a mixing rate with respect to concrete is 0.4 to 2.0% by volume. can do.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 1 to 5 show an embodiment of a segment according to the present invention. The segment shown in the figure is composed of a plurality of curved plate-like segment pieces 10 as in the conventional example described above, and each segment piece 10 includes a pair of inter-piece joining surfaces 12 and an inter-ring joining surface. .
[0021]
The plurality of segment pieces 10 are adjacently arranged along the circumferential direction of the tunnel excavation surface so that the inter-piece joining surfaces 12 are joined to each other, and the adjacent segment pieces 10 are mutually connected to form a ring body. I'm assembling.
[0022]
As the excavation progresses, the ring bodies are sequentially installed adjacent to each other along the tunnel axis direction so that the joint surfaces between the rings are joined to each other. It is constructed in a cylindrical shape inside the tunnel excavation surface, thereby lining the tunnel excavation surface.
[0023]
FIG. 1 is a cross-sectional view of a segment piece 10. The segment piece 10 shown in FIG. 1 includes a curved plate-shaped segment piece main body 14 formed by placing concrete and a main bar 16 embedded in the main body 14. , A joint metal fitting 18 and a connection metal fitting 20.
[0024]
The segment piece body 14 includes an upper surface 22 and a lower surface 24 that are curved with substantially the same curvature. In the present embodiment, the concrete used to form the segment piece body 14 is fiber-reinforced high-fluidity concrete.
[0025]
In this fiber-reinforced high-fluidity concrete, steel fibers are reinforcing fibers, and a predetermined amount of short-fiber-like steel fibers are mixed in the concrete. The high fluidity concrete ensures separation resistance and can obtain high fluidity by, for example, mixing powder such as silica fume or adding a thickener.
[0026]
The steel fiber is, for example, a short fiber having a length of 20 to 60 mm, a diameter of 0.3 to 0.9 mm, and an aspect ratio of 30 to 100, and the mixing ratio with respect to concrete is 0.4 to 2.0 volume%. And
[0027]
In the present embodiment, the main bar 16 is formed so as to bend along the shape of the inner and outer surfaces of the segment piece main body 14, and is arranged in two steps at a predetermined interval in the thickness direction of the segment piece main body 14. Has been.
[0028]
Further, as shown in FIG. 2 in the state of arrangement in the width direction with respect to the segment piece main body 14, a plurality of main bars 16 are arranged for each stage at a predetermined interval in the width direction of the main body 14.
[0029]
As shown in FIG. 1, the joint fitting 18 is embedded in the segment piece body 14 such that one end faces the inter-piece joint surface 12 and the end surface is exposed to the joint surface 12.
[0030]
In the case of the present embodiment, in the segment piece 10 shown in FIG. 1, the joint fittings 18 having the same configuration are disposed on the piece-to-piece joint surfaces 12 provided at both ends of the segment piece body 14. .
[0031]
Details of the fitting 18 are shown in FIGS. The joint fitting 18 shown in these drawings includes a C-shaped metal piece 18a having a substantially C-shaped cross section, and a mounting flange 18b integrally provided on the back side of the C-shaped metal piece 18a.
[0032]
The C-shaped metal piece 18a is provided with a fitting portion 18c opened at one end, and in this fitting portion 18c, a fitting fitting provided on another segment piece 10 installed adjacent to the inter-piece joint surface 12 is provided. A convex part is inserted and the joint surfaces 12 between pieces are connected.
[0033]
Four insertion holes 18d are formed through the mounting flange 18b at a predetermined interval. A connecting rod 28 of a connecting fitting 20 to be described later is inserted through the insertion hole 18d.
[0034]
On the other hand, the connecting fitting 20 is embedded in the segment piece main body 14 so that both ends thereof are joined to the main reinforcing bar 16 and the joint fitting 18, respectively. In this embodiment, the main reinforcing stand 26 and the connecting rod 28 are provided. And.
[0035]
As shown in detail in FIG. 2, the connection frame 26 includes an upper plate 26a, a lower plate 26b, and a plurality of connection plates 26c that connect the plates 26a and 26b. ing.
[0036]
The connection frame 26 is provided at a position close to the inter-piece joint surface 12 so that the connection plate 26 c is substantially parallel to the joint surface 12. The upper and lower plates 26a and 26b are provided on both ends of the connection plate 26c, and are arranged so that the main surfaces intersect with the main surface of the connection plate 26c at a predetermined angle.
[0037]
The upper and lower plates 26a and 26b are provided with a plurality of U-shaped grooves 26d opened at the upper ends at predetermined intervals. The main bar 16 is fitted and inserted into each U-shaped groove 26d.
[0038]
The main bar 16 is held in a state of being positioned at a predetermined position with respect to the segment piece main body 14 by being fitted and inserted into the U-shaped groove 26d of the connecting frame 26.
[0039]
In the case of the present embodiment, the connecting rod 28 is bent into a substantially concave shape, and is inserted into the insertion hole 18d of the joint fitting 18 so that both ends of the connecting rod 28 are on the upper side of the connecting frame 26 and lower plates 26a and 26b. It is fixed to the front of the machine by welding.
[0040]
In this case, the connecting rod 28 inserted into the insertion hole 18d of the joint fitting 18 is fixed to the joint fitting 18 by driving a wedge between the insertion hole 18d. The wedge is not necessarily required. For example, the inner diameter of the insertion hole 18d, the connecting rod 28, and the outer diameter can be inserted, and the connecting rod 28 is formed so as to be in close contact with each other. Both may be fixed by bending into a concave shape.
[0041]
According to the connection fitting 20 configured in this manner, by inserting the connection rod 28 into the insertion hole 18d of the joint fitting 18, one end side of the connection fitting 20 is locked to the joint fitting 18, and the two are joined. By fitting the main reinforcing bar 16 into the U-shaped groove 26 d of the connecting frame 26, the other end of the connecting fitting 20 is joined to the main reinforcing bar 16.
[0042]
In this case, the connection frame 26 and the connection rod 28 are fixedly connected because both ends of the connection rod 28 are fixed to the upper and lower plates 26a and 26b of the connection frame 26.
[0043]
Accordingly, the left connecting bracket 26 and the right connecting bracket 26 are fitted and locked together by interposing the left connecting rod 28, the connecting mount 26, the main reinforcement 16, the right connecting mount 26, and the connecting rod 28. Or it is directly connected by fixed joining.
[0044]
Now, according to the segment comprised as mentioned above, the segment piece 10 is formed by placing concrete, a curved plate-shaped segment piece main body 14, a main bar 16 embedded in the segment piece main body 14, and one end side being a piece. A joint fitting 18 embedded in the segment piece body 14 so as to face the inter-joint surface 12 and a connection fitting embedded in the segment piece body 14 so that both ends thereof are joined to the main bar 16 and the joint bracket 18, respectively. 20, stress can be transmitted directly from the joint fitting 18 to the main reinforcement 16 via the connection fitting 20, and the anchor reinforcement and the distribution reinforcement are omitted to reduce the cost. Can do.
[0045]
Thus, when the main reinforcement 16 and the joint fitting 18 are directly connected by the connecting fitting 20, when considering a circular cross section in which the segment pieces 10 are assembled in an annular shape, the main reinforcement 16 is connected in a ring shape, and the flow of stress as a circular pipe Becomes smooth and has a reasonable structure.
[0046]
In the case of the present embodiment, the curved plate-shaped segment piece main body 14 formed by placing concrete is made of steel fiber reinforced high-fluidity concrete. Deformation performance increases and toughness increases.
[0047]
Moreover, since steel fiber restrains the progress of the crack which exists in the segment piece main body 14 by steel fiber reinforcement, the resistance with respect to crack generation becomes high. Furthermore, even if there is a potential crack in the segment piece body 14 due to the steel fiber reinforcement, it does not peel off, which is advantageous when omitting the secondary lining.
[0048]
Moreover, the tensile strength of the segment piece main body 14 becomes large by steel fiber reinforcement, and there exists a possibility that the amount of main reinforcement can be reduced. Furthermore, since the shear strength of the segment piece main body 14 is increased by the steel fiber reinforcement, the performance does not deteriorate even if the reinforcing bars are omitted.
[0049]
【The invention's effect】
As described above in detail, according to the segment according to the present invention, stress can be transmitted smoothly and the amount of reinforcing bars can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a segment piece constituting a segment according to the present invention.
FIG. 2 is an explanatory side view of FIG. 1;
3 is a plan view of a joint fitting used in the segment piece shown in FIG. 1. FIG.
4 is a side view of FIG. 3. FIG.
FIG. 5 is an explanatory view showing a state where a connecting rod is inserted into the joint fitting shown in FIG. 1;
FIG. 6 is a cross-sectional view of a conventional segment piece.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Segment piece 12 Interpiece joining surface 14 Segment piece main body 16 Main reinforcement 18 Joint metal fitting 20 Connection metal fitting 26 Main reinforcement frame 28 Connection rod

Claims (4)

It is composed of a plurality of curved plate-like segment pieces with a pair of pieces and an inter-ring joining surface,
Adjacently arranged along the circumferential direction of the tunnel excavation surface so that the inter-piece joint surfaces are joined to each other, and assembling a ring body by interconnecting adjacent segment pieces, with the progress of excavation, The ring bodies are sequentially installed along the tunnel axis direction so that the joint surfaces between the rings are joined to each other, and the adjacent ring bodies are connected to each other to form a cylindrical shape inside the tunnel excavation surface. In the segment to be built,
The segment piece is a curved plate segment piece body formed by placing concrete;
Main bars embedded in the segment piece body;
A fitting fitting embedded in the segment piece body, with one end facing the joint surface between the pieces,
Both ends are joined to the main bar and the joint fitting, respectively, and a connection fitting embedded in the segment piece body,
The connection fitting includes a flat main bar pedestal on which an end of the main bar is fitted and arranged, and a plurality of connection rods formed in a substantially concave shape,
The main muscle mount is composed of an upper plate, a lower plate, and a plurality of connecting plates that connect these plates,
Each of the connecting rods has a concave base end side fixed in the insertion hole of the joint fitting, and a pair of other end sides fixed to the upper and lower plates, respectively . The segment according to claim 1, wherein the segment piece body is formed of fiber-reinforced high-fluidity concrete. The segment according to claim 2, wherein the fiber reinforcement of the high fluidity concrete is made of steel fibers. The steel fiber is a short fiber having a length of 20 to 60 mm, a diameter of 0.3 to 0.9 mm, and an aspect ratio of 30 to 100, and a mixing rate with respect to concrete is 0.4 to 2.0% by volume. The segment according to claim 3.

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