JP7373640B2 - Segment piece and segment ring - Google Patents

Description

The present invention relates to a segment piece for tunnel lining, and a segment ring (tunnel lining body) assembled from a plurality of segment pieces.

Segment pieces are used for lining shield tunnels such as road tunnels and underground river tunnels.
The segment piece is a curved divided body made of reinforced concrete, and a segment ring is formed by combining a plurality of segment pieces in the circumferential direction of the tunnel along the excavated surface of the tunnel. The segment ring is connected to the formed segment ring in the tunnel axial direction, thereby constructing a cylindrical tunnel lining.

Segment pieces generally include a concrete structure that forms the segment piece, a plurality of main reinforcing bars that are buried within the concrete structure and extend in the tunnel circumferential direction, and adjacent segments that are provided on the circumferential end face of the concrete structure. It is configured to include a fitting joint (joint hardware) that connects the pieces, and an anchor reinforcement that is connected to the back side of the fitting joint and is buried in the concrete structure.
Specifically, a main reinforcing bar, a fitting joint, and an anchor bar are set at predetermined positions in a formwork, and concrete is poured to form a segment piece made of reinforced concrete.

Further, in Patent Documents 1 and 2, in order to reduce weight, anchor bars are eliminated, and both ends of the main reinforcing bar are extended and connected to the back side of the joint hardware.

Japanese Patent Application Publication No. 2002-021487 JP2017-043884A

By the way, in recent years, deep shield tunnels are being planned. In deep tunnels, high earth pressure and high water pressure generate large compressive forces in the circumferential direction of the tunnel between adjacent segment pieces.

At this time, since there are no main reinforcing bars on the joint surface of the segment piece, the vicinity of the joint surface becomes a weak point. If the thickness of the segment piece in the tunnel radial direction is increased, the yield strength can be improved, but the excavation diameter of the tunnel becomes larger accordingly, leading to an increase in cost. Therefore, there is a need to improve the yield strength of the segment pieces without increasing the thickness of the segment pieces.

In this regard, the techniques described in Patent Documents 1 and 2 can directly transmit the compressive force generated between the joint hardware of adjacent segment pieces to the main reinforcing bars, and can improve the strength.

However, it is understood that compressive force can be reliably transmitted by integrating the joint hardware and the main reinforcing bars by a connecting mechanism for transmitting compressive force, as in Patent Documents 1 and 2, but in reality, manufacturing Moreover, it is difficult to match the length, and using a length adjustment means increases the number of parts and takes time to adjust the length, which poses problems in terms of process and cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a segment piece that can be manufactured relatively easily and has increased resistance against compressive force in the tunnel circumferential direction. . In particular, the present invention makes it possible to easily adjust the length of steel materials that transmit compressive force in the tunnel circumferential direction, and to suitably transmit the compressive force generated in the tunnel circumferential direction without using any parts as length adjustment means. The present invention provides a segment piece or a segment ring made of segment pieces.

The segment piece in the present invention includes a concrete structure that forms the segment piece, a plurality of main steel members that are embedded in the concrete structure and extend in the tunnel circumferential direction, and a plurality of main steel members that are embedded in the concrete structure and extend in the tunnel circumferential direction. The concrete structure includes steel compressive force transmitting members arranged and exposed, and a plurality of reinforcing steel members connected to the back side of the compressive force transmitting members and buried in the concrete structure. Concrete is exposed on the side of the body that runs along the excavated surface of the tunnel, and adjacent segment pieces are pressed against each other by the end surfaces of the concrete structure in the tunnel circumferential direction and by the compressive force transmitting members.
In the present invention, the reinforcing steel material is arranged at a predetermined level with respect to the main steel material so that the compressive force generated between the compressive force transmission members is transmitted from the reinforcing steel material to the main steel material via concrete. are placed along the length of.

The present invention also provides a segment ring in which the plurality of segment pieces described above are combined in the tunnel circumferential direction to form a tunnel lining.

According to the present invention, the compressive force generated between adjacent segment pieces due to high earth pressure and high water pressure is transmitted from the compressive force transmission member to the reinforcing steel material (anchor bar), and from the reinforcing steel material (anchor bar) to the concrete. This can be transmitted to the main steel material (main reinforcing bar) via the segment piece, and the strength of the segment ring assembled with the segment piece can be improved.

Explanatory diagram of segment piece and segment ring Detailed view of a segment piece showing the first embodiment of the present invention Explanatory diagram of the arrangement of anchor muscles Explanatory diagram of the placement of anchor bars relative to the main reinforcing bars Plan view for explaining the joint structure of adjacent segment pieces Detailed view of a segment piece showing a second embodiment of the invention Detailed view of a segment piece showing a third embodiment of the present invention

Embodiments of the present invention will be described in detail below.
FIG. 1 is an explanatory diagram of a segment piece and a segment ring.

The segment ring 100 is formed by combining a plurality of segment pieces 1 having a predetermined unit length in the tunnel axial direction in the tunnel circumferential direction along the tunnel excavation surface, and forms one unit of the tunnel lining. Eggplant. A tunnel lining is constructed by connecting the plurality of segment rings in the tunnel axial direction.

Therefore, the segment piece 1 forms a "curved divided body formed by dividing a cylindrical tunnel structure having a predetermined unit length in the tunnel axis direction into a plurality of parts in the circumferential direction". In addition to the A segment with common specifications, the segment pieces include a wedge-shaped K segment in the tunnel axis direction that is installed at the end of each segment ring, and a B segment that is placed between the K segment and the A segment. be.

Assembly of the segment rings takes place in a shield machine. Therefore, earth pressure and water pressure are not applied to the segment ring during assembly.
As excavation progresses, when the assembled segment rings are exposed outside the shield machine, large earth pressure and water pressure act on the segment rings. As a result, a large compressive force is generated between adjacent segment pieces in the tunnel circumferential direction.

In particular, as tunnels become deeper, the compressive force applied to the segment pieces in the circumferential direction of the tunnel tends to increase due to high earth pressure and high water pressure, and there is a need to improve the strength of the segment pieces. The present invention was made with attention to such problems, and provides a segment piece with high yield strength.

FIG. 2 shows a first embodiment of the present invention, in which (A) is an end view of a segment piece viewed from the tunnel circumferential direction, (B) is a sectional view of the segment piece viewed from the tunnel axial direction, and (C) is an adjacent FIG. 3 is a cross-sectional view of the press-contact portions of matching segment pieces viewed from the tunnel axis direction.

The segment piece 1 has an RC structure (reinforced concrete structure) and is mainly composed of a concrete structure 2.
The concrete structure 2 is formed by setting reinforcing bars and the like, which will be described later, in a formwork having a predetermined shape, and then pouring concrete, solidifying it, and removing the form.

Here, the concrete structure 2 is formed to form a "curved divided body formed by dividing a cylindrical tunnel structure having a predetermined length in the tunnel axis direction into a plurality of parts in the circumferential direction."

Therefore, the concrete structure 2 includes an outer cylindrical surface 2a along the tunnel excavation surface, an inner cylindrical surface 2b, front and rear end surfaces 2c and 2d in the tunnel axis direction, left and right end surfaces in the tunnel circumferential direction (adjacent segment (joint surfaces with the piece) 2e and 2f.

Further, on the outer surface of the concrete structure 2, seal grooves 3 are formed in two stages on the outer circumferential side and the inner circumferential side in the tunnel radial direction from the end surface 2e to the end surface 2c, the end surface 2f, and the end surface 2d, and return to the end surface 2e. has been done. Prior to assembly of the segment rings, water-expandable seal members (not shown) are installed in these seal grooves 3.

Main reinforcing bars 4, hoop bars 5, and hook bars 6 are provided within the concrete structure 2.
The main reinforcing bars 4 are buried as main steel members in the concrete structure 2 and extend in the circumferential direction of the tunnel.
In this example, as can be seen from FIG. 2(A), the main reinforcing bars 4 are 2×12, that is, two stages are provided in the tunnel radial direction, and a plurality (12 main reinforcing bars) are provided in each stage in the tunnel axial direction.

The length of the main reinforcing bar 4 in the tunnel circumferential direction is shorter than the length of the concrete structure 2 in the tunnel circumferential direction, as can be seen from FIG. 2(B). Therefore, a predetermined interval (K in FIG. 4) is provided between both ends of the main reinforcing bar 4 and both end surfaces 2e, 2f of the concrete structure 2.

Hoop reinforcements (band reinforcements) 5 connect two stages of main reinforcing bars 4 in a hoop shape in the tunnel radial direction, and are arranged in plurality at equal intervals in the extending direction of the main reinforcing bars 4 (in this example, it can be seen from FIG. 2(B) (12 pieces) are provided.

The hook bars 6 are provided at the ends of the main reinforcing bars 4. That is, two stages of main reinforcing bars 4 are connected at both ends in the circumferential direction of the tunnel, and a plurality of main reinforcing bars 4 are connected in the direction in which the main reinforcing bars 4 are arranged (as can be seen from FIG. ) provided.

A compressive force transmitting member 7 made of a steel plate is provided on both end faces 2e, 2f of the concrete structure 2 in the tunnel circumferential direction in such a manner as to be exposed flush with the end faces.

The compressive force transmission member 7 is provided in two stages in the tunnel radial direction. When viewed from the end faces 2e and 2f, the two stages of compressive force transmission members 7 are arranged between the two stages of seal grooves 3 and between the two stages of main reinforcing bars 4.
The compressive force transmitting members 7 at each stage are arranged in a band shape in the tunnel axis direction. However, the compressive force transmitting member 7 of each stage is divided into two in the tunnel axial direction from the viewpoint of being able to transmit the compressive force applied to the segment piece in the tunnel circumferential direction to adjacent segment pieces.
Here, the adjacent segment pieces 1 and 1' are brought into pressure contact with each other by the compressive force transmitting members 7.

A plurality of anchor bars 8 are connected to the back side of the compressive force transmitting member 7 in a manner that protrudes from the back face of the compressive force transmitting member 7 for anchorage, and the anchor bars 8 are reinforced within the concrete structure 2. It will be buried as steel material.
Therefore, like the compressive force transmission member 7, the anchor bars 8 are provided in two stages in the tunnel radial direction.

In this example, as can be seen from FIG. 2(A), the anchor bars 8 are provided in 2×6 pieces, that is, in two stages in the tunnel radial direction, and a plurality (six pieces) in each stage in the tunnel axial direction. Since the compressive force transmitting member 7 is divided into two in the tunnel axial direction, three anchor bars 8 are connected to one compressive force transmitting member 7.

Here, the anchor reinforcing bars 8 are placed along the main reinforcing bars 4 within the concrete structure 2.
That is, the anchor bars 8 are arranged along the main reinforcing bars 4 so that the compressive force generated between the compressive force transmitting members 7 is transmitted from the anchor bars 8 to the main reinforcing bars 4 via the concrete. . That is, the anchor reinforcing bars 8 and the main reinforcing bars 4 are arranged at a predetermined distance apart from each other so that a part of each is parallel to each other, and so that they are parallel to each other by a predetermined distance.

In other words, by aligning the anchor bars 8 with the main reinforcing bars 4 and appropriately setting the length of the alignment and the interval between the main reinforcing bars 4 and the anchor bars 8 in the range where they are aligned, as described below. , the above compressive force is transmitted from the anchor reinforcement 8 to the main reinforcing reinforcement 4 via the concrete.

In particular, in this example, as can be seen from the explanatory diagrams in FIG. 2(A) and FIG. 3, 12 main reinforcing bars 4 and 6 anchor bars 8 are arranged in each stage, , one by one, along the two main reinforcing bars 4. This allows the compressive force to be transmitted to be distributed.

Also, when viewed in the circumferential direction of the tunnel, as can be seen from the explanatory diagram of FIG. 3, the anchor bars 8 (see, for example, the anchor bars 8 in the upper left of FIG. 3) are located at the apex of an acute triangle with respect to the two main reinforcing bars 4 along which they are aligned. It will be placed in the position. Thereby, the compressive force to be transmitted can be distributed almost evenly.
In the figure, the anchor bars 8 are placed at the vertices of the isosceles triangle so that they are equidistant from the two main reinforcing bars 4 that are to be followed when viewed in the circumferential direction of the tunnel. . However, it is not necessary that the shape be an isosceles triangle, and a necessary and sufficient distribution performance can be obtained as long as the positional relationship forms an acute triangle.

The concrete structure 2, the compressive force transmission member 7, and the anchor reinforcement 8 will be explained in more detail with reference to the explanatory diagram of FIG.

The thickness T of the segment piece 1 (concrete structure 2) in the tunnel radial direction is preferably 400 to 700 mm, more preferably 450 to 650 mm. This is because if it is smaller than this, compressive force cannot be transmitted, and if it is larger than this, the excavation cross section will become large. The length of the segment piece 1 (concrete structure 2) in the tunnel axial direction is usually 1,000 to 2,000 mm, and in recent years, 1,500 to 2,000 mm is often used in long-distance tunnels.

The distance t1 from the outer circumferential side surface 2a of the concrete structure 2 to the center of the outer circumferential compressive force transmission member 7 (and anchor reinforcement 8), and the distance t1 from the inner circumferential side surface 2b of the concrete structure 2 to the inner circumferential side The distance t3 to the center of the compressive force transmission member 7 (and the anchor muscle 8) is preferably 0.15T to 0.40T, more preferably 0.20T to 0.35T. This is because compressive force cannot be transmitted even if it is smaller or larger than this.

The reinforcing bar diameter (nominal diameter) of the anchor bar 8 is the same as the reinforcing bar diameter of the main reinforcing bar 4, preferably D32 to D51, more preferably D35 to D41. If it is smaller than this, the number of reinforcing bars will increase; if it is larger than this, the number of reinforcing bars will decrease, but the compressive force acting on the entire cross section of the segment piece will not be properly transmitted, and since the amount of reinforcing bars will increase, the weight of the segment itself will increase. It's getting too big.

The arrangement pitch p of the anchor bars 8 in the tunnel axial direction is preferably 4 to 10 times, more preferably 6 to 8 times, the reinforcing bar diameter (nominal diameter) of the anchor bars 8. If it is smaller than this, the distribution of compressive force acting on the entire cross section of the segment piece is good, but the manufacturing effort increases, and if it is larger than this, the compressive force acting on the entire cross section of the segment piece cannot be transmitted properly. be.

Next, a preferable relationship between the anchor bars 8 and the main reinforcing bars 4 will be described with reference to the explanatory diagrams of FIGS. 3 and 4.
Referring to FIG. 4, the length (overlapping length) L of the anchor reinforcement 8 along the main reinforcement 4 is preferably 8D or more, more preferably 8D or more, where D is the reinforcement diameter (nominal diameter) of the anchor reinforcement 8. shall be 12D or more. This is because if it is shorter than this, the compressive force acting on the anchor muscle 8 cannot be sufficiently transmitted.

Further, referring to FIG. 3, the distance (space) S between the surfaces of the main reinforcing bars 4 and the anchor bars 8 is preferably 2D or less, more preferably 2D or less, where D is the reinforcing bar diameter (nominal diameter) of the anchor bars 8. shall be less than or equal to D. This is because if the distance is greater than this, the compressive force acting on the anchor muscle 8 cannot be sufficiently transmitted. Moreover, if it is 2D or less, the main reinforcing bars 4 and the anchor bars 8 can be suitably arranged within the width of the thickness T of the segment piece 1 (concrete structure 2) in the tunnel radial direction.

As mentioned above, the length L of the anchor bar 8 along the main reinforcing bar 4 is 8D or more (more preferably 12D or more), where the diameter of the anchor bar 8 is D, and the length L of the anchor bar 8 along the main reinforcing bar 4 is 8D or more (more preferably 12D or more) By setting the distance S between the surfaces to 2D or less (more preferably D or less), the compressive force generated between the compressive force transmission members 7 is transmitted from the anchor reinforcements 8 to the main reinforcement bars 4 via the concrete. This will lead to

In addition, since the main reinforcing bar 4 is actually curved, if the anchor bar 8 is not curved, the main reinforcing bar 4 and the anchor bar 8 are not parallel to each other. In that case, the distance S between the surfaces of the main reinforcing bars 4 and anchor bars 8 changes within the range in which the anchor bars 8 are placed along the main reinforcing bars 4. Therefore, the maximum value of the distance S within the range along the line should be 2.4D or less, preferably 2D or less, more preferably D or less.

Further, a predetermined interval (K in FIG. 4) between both end faces 2e and 2f of the segment piece and both end faces of the main reinforcing bar 4 also functions as an overlap, but the interval K must be 0.5D or more. Therefore, it is preferable to set it to 2.0D or less. In order to transmit the compressive force generated in the circumferential direction of the tunnel, by setting an interval different from the normal cover standard value, the compressive force generated on each end face (2e, 2f) of the segment piece is transferred to the opposing segment piece. The information can be reliably transmitted to the main reinforcing bars 4.

As described above, various setting conditions for anchor bars (reinforcing steel materials) and main reinforcing bars (main steel materials) have been found at each end of adjacent segment pieces to suitably transmit the compressive force generated in the circumferential direction of the tunnel. It is. Therefore, according to the present embodiment, it is possible to easily adjust the length of the steel material that transmits the compressive force, and it is possible to suitably transmit the compressive force generated in the tunnel circumferential direction without using any parts as length adjustment means. I can do it.

In this embodiment, adjacent segment pieces are further provided between the two stages of compressive force transmitting members 7 on the end surfaces 2e and 2f of the concrete structure 2 in the tunnel circumferential direction (joint surfaces with adjacent segment pieces). Fitting joints (11, 12) are provided that connect in the circumferential direction of the tunnel.

FIG. 5 is a plan view for explaining the joint structure of adjacent segment pieces.
The fitting joint will be described with reference to FIGS. 2 and 5.

The fitting joint consists of a female joint hardware 11 and a male joint hardware 12, and the female joint hardware 11 and the male joint hardware 12 are arranged on one joint surface 2e in the tunnel axial direction, front and rear. provided. Further, on the other joint surface 2f, a male joint metal fitting 12 and a female joint metal fitting 11 are provided side by side in the tunnel axis direction with the front and back reversed.

The female joint hardware 11 includes an anchor portion 11a buried within the concrete structure 2, and a fitted portion 11b integrally formed on the distal end side of the anchor portion 11a. Two anchor bars 13 for fixing are fixed and protrude from the back side of the anchor portion 11a.

The fitted portion 11b has a C-shaped groove 11c (in other words, a hole with a slit and a circular cross section) 11c. This groove 11c has a gentle truncated conical taper in the tunnel axis direction, and is formed so that the inner diameter (groove diameter) gradually decreases (or increases) in the tunnel axis direction.

The male joint hardware 12 includes an anchor part 12a buried in the concrete structure 2, a support part 12b protruding from the tip side of the anchor part 12a in a plate shape, and a bulge formed at the tip side of the support part 12b. It includes a protruding portion 12c having a circular cross section. Two anchor bars 14 for fixing are fixed and protrude from the back side of the anchor part 12a.

The protruding portion 12c has a circular cross section with a diameter larger than the plate thickness of the support portion 12b when viewed in the tunnel axial direction, and extends in the tunnel axial direction. The protruding portion 12c has a gentle truncated conical taper in the tunnel axial direction, and is formed so that its outer diameter gradually decreases (or increases) in the tunnel axial direction.

On the other hand, on the joint surface 2e of the concrete structure 2 in the tunnel circumferential direction, the female joint hardware 11 is stored from the front end face 2c of the concrete structure 2 to the installation site of the female joint hardware 11 in the tunnel axis direction. A groove 15 is formed. Similarly, on the joint surface 2f of the concrete structure 2 in the tunnel circumferential direction, from the rear end surface 2d of the concrete structure 2 to the installation site of the female joint hardware 11 in the tunnel axis direction, there is a female joint hardware 11. A storage groove 15 is formed.

The female joint hardware 11 is installed behind the front end surface 2c or in front of the rear end surface 2d in the tunnel axis direction of the storage groove 15, and is arranged so that the fitted portion 11b does not protrude from the joint surface. Ru. The anchor part 11a and the anchor reinforcement 13 of the female joint hardware 11 are buried in the concrete structure 2.

The male joint hardware 12 is aligned such that the support portion 12b and the protruding strip portion 12c protrude from the joint surface 2e or 2f of the concrete structure 2, and the anchor portion 12a and the anchor reinforcement 14 are buried within the concrete structure 2. be done.

Here, the convex strip 12c of the male joint hardware 12 can be fitted into the groove 11c of the female joint hardware 11, and at this time, the support portion 12b of the male joint hardware 12 is connected to the female joint hardware 11. It can be located in the slit at the tip of the fitted portion 11b.

Therefore, as shown in FIG. 5, for example, by moving the other segment piece 1' in the direction of the arrow in the figure while fixing one segment piece 1, the groove 11c of the female joint hardware 11 can be moved. The protruding portion 12c of the male joint hardware 12 can be fitted in the tunnel axial direction, and this fitting allows the two segment pieces 1, 1' to be connected in the tunnel circumferential direction.
Therefore, the fitting joints (11, 12) can connect adjacent segment pieces in the tunnel circumferential direction by sliding the adjacent segment pieces in the tunnel axial direction and fitting them. The compressive force transmitting member 7 is arranged in a band shape in the tunnel axis direction, and its direction coincides with the direction in which it is slid to fit the fitting joints (11, 12). Therefore, even if the fitting of the fitting joints (11, 12) is insufficient (if there is play), the compressive force transmitting members 7 in the adjacent segment pieces 1, 1' are in opposing positions. The compressive force acting between the segment pieces can be transmitted.

According to this embodiment, even if a large compressive force is generated between adjacent segment pieces 1 due to high earth pressure and high water pressure, this compressive force is transferred from the compressive force transmission member 7 to the anchor reinforcement (reinforcing steel material) 8. It can be transmitted from the anchor reinforcement 8 to the main reinforcing bar (main steel material) 4 along which the anchor reinforcement 8 runs through the concrete, and the strength of the segment piece 1 can be improved.

In particular, by aligning the anchor bars 8 with the main reinforcing bars 4 and appropriately setting the length L of the alignment and the distance S between the main reinforcing bars 4 and the anchor bars 8 within the range of the alignment, In other words, the length L of the anchor reinforcement 8 along the main reinforcement 4 is 8D or more (more preferably 12D or more), where the diameter of the anchor reinforcement 8 is D, and the distance between the surfaces of the main reinforcement 4 and the anchor reinforcement 8 is set to 8D or more (more preferably 12D or more). By setting the distance S to 2D or less (more preferably D or less), a sufficient compressive force transmission effect can be obtained and the yield strength of the segment piece 1 can be improved.

On the other hand, the fitting joints (11, 12) are not required to function as compressive force transmitting members, but only need to have a connecting function when assembling segment rings that are not subjected to earth pressure or water pressure. Therefore, the fitting joint (11, 12) of this embodiment has only one stage and can be miniaturized.

In this embodiment, a flat steel plate is used as the compressive force transmission member 7, and the flat surfaces are brought into contact (pressure contact) with each other. It may be possible to resist the shear force of.

Next, other embodiments of the present invention will be described.
FIG. 6 shows a second embodiment of the present invention, in which (A) is an end view of a segment piece viewed from the tunnel circumferential direction, (B) is a sectional view of the segment piece viewed from the tunnel axial direction, and (C) is an adjacent FIG. 3 is a cross-sectional view of the press-contact portions of matching segment pieces viewed from the tunnel axis direction.
Elements corresponding to those in the first embodiment (FIG. 2) are given the same reference numerals, and different elements will be explained.

In the first embodiment (FIG. 2), the compressive force transmitting members 7 are arranged in a band shape in the tunnel axial direction on the end face of the segment piece 1 (concrete structure 2) in the tunnel circumferential direction, and one compressive force transmitting member 7 A plurality of anchor bars 8 are connected to each other.
On the other hand, in the second embodiment (FIG. 6), a plurality of compressive force transmission members 20 are arranged at intervals in the tunnel axial direction on the end face of the segment piece 1 (concrete structure 2) in the tunnel circumferential direction, One anchor muscle 8 is connected to one compressive force transmission member 20.

In other words, in the second embodiment (FIG. 6), a head having a larger diameter than the anchor muscle 8 is provided at the exposed end of each anchor muscle 8, and this is used as the compressive force transmission member 20.

Even in the second embodiment (FIG. 6) having such a configuration, the same effects as in the first embodiment (FIG. 1) can be obtained.

FIG. 7 shows a third embodiment of the present invention, in which (A) is an end view of a segment piece viewed from the tunnel circumferential direction, (B) is a sectional view of the segment piece viewed from the tunnel axial direction, and (C) is an adjacent FIG. 3 is a cross-sectional view of the press-contact portions of matching segment pieces viewed from the tunnel axis direction.
Elements corresponding to those in the first embodiment (FIG. 2) are given the same reference numerals, and different elements will be explained.

In the third embodiment (FIG. 7), compressive force transmitting members 31 and 32 are used instead of the compressive force transmitting member 7 of the first embodiment (FIG. 2). The compressive force transmitting members 31 and 32 are characterized in that they also serve as fitting joints (female joint hardware 11 and male joint hardware 12) that connect adjacent segment pieces.

The compressive force transmitting members 31 and 32 are installed on both end surfaces (joint surfaces) 2e and 2f of the concrete structure 2 in the tunnel circumferential direction so as to be exposed flush with the end surfaces. A type joint hardware 11 is integrated, and a male type joint hardware 12 is integrated with the compressive force transmission member 32.

Here, on one joint surface 2e, compressive force transmitting members 31 (female joint hardware 11) are provided in two stages on the front side in the tunnel axial direction, and compressive force transmitting members 32 (male joint hardware 11) are provided on the rear side. Hardware 12) is provided in two stages.
In addition, on the other joint surface 2f, the front and rear sides are reversed, and compressive force transmitting members 32 (male type joint hardware 12) are provided in two stages on the front side, and compressive force transmitting members 31 (female type joint hardware 12) are provided on the rear side. Joint hardware 11) is provided in two stages.
Here, the adjacent segment pieces 1 and 1' are pressed against each other by the compressive force transmitting members 31 and 32, specifically, one compressive force transmitting member 31 and the other compressive force transmitting member 32.

The female joint hardware 11 integrated with the compressive force transmission member 31 is provided with, for example, three anchor lines 13 for fixing on the back side of its anchor portion.
Further, the male joint hardware 12 that is integrated with the compressive force transmission member 32 is provided with, for example, three anchor lines 14 for fixing on the back side of its anchor portion.
These anchor bars (reinforcing steel materials) 13 and 14 have the same diameter as the main reinforcing bars (main steel material) 4.

The anchor bars 13 and 14 that are integrated with the compressive force transmitting members 31 and 32 (the female joint hardware 11 and the male joint hardware 12) are similar to the anchor bars 8 that are integrated with the compressive force transmitting member 7 of the first embodiment. It is placed along the main reinforcing bars 4 within the concrete structure 2.
That is, the anchor bars 13 and 14 are connected to the main reinforcing bars 4 so that the compressive force generated between the compressive force transmitting members 31 and 32 is transmitted from the anchor bars 13 and 14 to the main reinforcing bars 4 via the concrete. placed side by side.

In particular, in this example, the anchor bars 13 or 14 are aligned one by one with respect to the two main reinforcing bars 4, and when viewed in the circumferential direction of the tunnel, the anchor bars 13 or 14 are aligned with the two main reinforcing bars 4. With respect to the reinforcing bar 4, it is placed at a position that is the apex of an acute triangle (including an isosceles triangle).

Here, the length (overlapping length) L of the anchor bars 13 or 14 along the main reinforcing bar 4 is preferably 8D or more, where D is the reinforcing bar diameter (nominal diameter) of the anchor bars 13 or 14, or more. Preferably, it is 12D or more.

Further, the distance (space) S between the surfaces of the main reinforcing bar 4 and the anchor bar 13 or 14 is preferably 2D or less, more preferably, Must be D or below.

According to this embodiment, even if a large compressive force is generated between adjacent segment pieces 1 due to high earth pressure and high water pressure, this compressive force is transferred from the compressive force transmitting members 31 and 32 to the joint hardware 11 and 12. It can be transmitted to the anchor bars 13 and 14, and from the anchor bars 13 and 14, via the concrete, to the main reinforcing bar 4 along which the anchor bars 13 and 14 lie, improving the strength of the segment piece 1. be able to.

In particular, the anchor bars 13 and 14 are aligned with the main reinforcing bar 4, and the length of the alignment and the spacing between the main reinforcing bar 4 and the anchor bars 13 and 14 within the range of alignment are determined appropriately as described above. By setting this, it is possible to enhance the compressive force transmission effect and improve the proof strength of the segment piece 1.

When adjacent segment pieces receive compressive force, the compressive force transmitting members 31 and 32 come into surface contact with each other, but at this time, the female joint hardware 11 and the male joint hardware 12 do not come into contact, and the compressive force transmitting members 31, 32 do not come into contact with each other. 32 does not inhibit surface touching between each other.
On the other hand, when adjacent segment pieces are subjected to a tensile force during assembly of the segment ring, the female joint hardware 11 and the male joint hardware 12 are connected to each other and can resist the tensile force.

Therefore, according to the present embodiment, the compressive force transmitting members 31 and 32 also serve as fitting joints (joint fittings 11 and 12) that connect adjacent segment pieces, thereby achieving the effect that the configuration can be simplified. .

The illustrated embodiments are merely illustrative of the present invention, and the present invention encompasses various improvements and improvements made by those skilled in the art within the scope of the claims, in addition to what is directly shown by the described embodiments. Needless to say, this includes changes.
The original claims of Japanese Patent Application No. 2018-133007 were as follows.
[Claim 1]
A segment piece for tunnel lining that comes into pressure contact with an adjacent segment piece at the end face in the circumferential direction of the tunnel,
A concrete structure forming a segment piece,
a plurality of main steel members embedded in the concrete structure and extending in the circumferential direction of the tunnel;
one to a plurality of compressive force transmitting members arranged and exposed on both ends of the concrete structure in the circumferential direction, respectively;
a plurality of reinforcing steel members connected to the back side of the compressive force transmission member and buried within the concrete structure;
It consists of
Adjacent segment pieces are pressed against each other by the compressive force transmitting members,
The reinforcing steel material is arranged along the main steel material so that the compressive force generated between the compressive force transmission members is transmitted from the reinforcing steel material to the main steel material via concrete. Features a segment piece.
[Claim 2]
The main steel material is provided in two stages in the tunnel radial direction, and a plurality of the main steel materials are provided in the tunnel axial direction of each stage,
The segment piece according to claim 1, wherein the compressive force transmitting member and the reinforcing steel material are also provided in two stages in the tunnel radial direction.
[Claim 3]
Claim 1 or claim 1, further comprising a fitting joint for connecting adjacent segment pieces between two stages of compressive force transmission members on end faces of the segment pieces in the tunnel circumferential direction. Segment piece described in 2.
[Claim 4]
The compressive force transmission member is arranged in a band shape in the tunnel axial direction on the end face of the segment piece in the tunnel circumferential direction,
The segment piece according to any one of claims 1 to 3, characterized in that a plurality of reinforcing steel members are connected to one compressive force transmission member.
[Claim 5]
A plurality of the compressive force transmission members are arranged at intervals in the tunnel axial direction on the end face of the segment piece in the tunnel circumferential direction,
The segment piece according to any one of claims 1 to 3, characterized in that one reinforcing steel material is connected to one compressive force transmission member.
[Claim 6]
3. The segment piece according to claim 1, wherein the compressive force transmission member also serves as a fitting joint that connects adjacent segment pieces.
[Claim 7]
The reinforcing steel materials are aligned one by one with respect to the two main steel materials,
The reinforcing steel material is arranged so as to form an apex of an acute triangle with respect to the two main steel materials to be aligned when viewed in the circumferential direction of the tunnel. The segment piece described in one of the above.
[Claim 8]
A segment ring in which a plurality of segment pieces are combined in the circumferential direction of a tunnel to form a tunnel lining,
The segment piece is
A concrete structure forming a segment piece,
a plurality of main steel members embedded in the concrete structure and extending in the circumferential direction of the tunnel;
one to a plurality of compressive force transmitting members arranged and exposed on both ends of the concrete structure in the circumferential direction, respectively;
a plurality of reinforcing steel members connected to the back side of the compressive force transmission member and buried within the concrete structure;
It consists of
Adjacent segment pieces are pressed against each other by the compressive force transmitting members,
The reinforcing steel material is arranged along the main steel material so that the compressive force generated between the compressive force transmission members is transmitted from the reinforcing steel material to the main steel material via concrete. Features a segment ring.

1 Segment piece 2 Concrete structure 3 Seal groove 4 Main reinforcing bar (main steel material)
5 Hoop reinforcement 6 Hook reinforcement 7 Compressive force transmission member 8 Anchor reinforcement (reinforced steel material)
11 Female joint hardware 11a Anchor part 11b Fitted part 11c Concave groove 12 Male joint hardware 12a Anchor part 12b Support part 12c Convex strips 13, 14 Anchor bar 15 Storage groove 20 Compressive force transmission members 31, 32 Compressive force transmission Element

Claims (7)

A segment piece for tunnel lining that comes into pressure contact with an adjacent segment piece at the end face in the circumferential direction of the tunnel,
A concrete structure forming a segment piece,
a plurality of main steel members embedded in the concrete structure and extending in the circumferential direction of the tunnel;
steel compressive force transmitting members arranged and exposed on both end faces of the concrete structure in the tunnel circumferential direction;
a plurality of reinforcing steel members connected to the back side of the compressive force transmission member and buried within the concrete structure;
It consists of
Concrete is exposed on the side of the concrete structure that runs along the tunnel excavation surface,
Adjacent segment pieces are in pressure contact with each other in the tunnel circumferential direction end surfaces of the concrete structure and with the compressive force transmission members,
The reinforcing steel material extends a predetermined length relative to the main steel material so that compressive force generated between the compressive force transmission members is transmitted from the reinforcing steel material to the main steel material via concrete. , placed along the
segment piece. The segment according to claim 1, wherein an exposed area of the compressive force transmitting member disposed on an end face of the concrete structure in the tunnel circumferential direction is smaller than an exposed area of concrete on the end face of the concrete structure in the tunnel circumferential direction. piece. further comprising sealing members attached to both end faces of the concrete structure in the tunnel circumferential direction and extending in the tunnel axial direction,
The segment piece according to claim 1 or 2, wherein the sealing member is attached to an outer peripheral side in the tunnel radial direction than the compressive force transmission member on an end face of the concrete structure in the tunnel circumferential direction. The segment piece according to any one of claims 1 to 3, wherein the compressive force transmission member is provided in two stages in the tunnel radial direction. According to any one of claims 1 to 3, the joint hardware is provided on an end face of the concrete structure in the tunnel circumferential direction, further comprising the joint hardware that connects adjacent segment pieces. Segment pieces listed. A segment ring in which a plurality of segment pieces are combined in the circumferential direction of a tunnel to form a tunnel lining,
The segment piece is
A concrete structure forming a segment piece,
a plurality of main steel members embedded in the concrete structure and extending in the circumferential direction of the tunnel;
steel compressive force transmitting members arranged and exposed on both end faces of the concrete structure in the tunnel circumferential direction;
a plurality of reinforcing steel members connected to the back side of the compressive force transmission member and buried within the concrete structure;
It consists of
Concrete is exposed on the side of the concrete structure that runs along the tunnel excavation surface,
Adjacent segment pieces are in pressure contact with each other in the tunnel circumferential direction end surfaces of the concrete structure and with the compressive force transmission members,
The reinforcing steel material extends a predetermined length relative to the main steel material so that compressive force generated between the compressive force transmission members is transmitted from the reinforcing steel material to the main steel material via concrete. , placed along the
segment ring. The segment according to claim 6, wherein an exposed area of the compressive force transmission member disposed on an end face of the concrete structure in the tunnel circumferential direction is smaller than an exposed area of concrete on the end face of the concrete structure in the tunnel circumferential direction. ring.