JP3929590B2 - Segment joint structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a joining structure of segments that form a cylindrical wall body in the axial direction of an excavation hole by connecting a plurality of them together.
[0002]
[Prior art]
As a method for constructing a tunnel, a so-called shield method is generally used in which a tubular wall body is constructed by assembling segments (mainly made of concrete or steel) on the inner surface side of an excavation hole.
As the segments used in this shield method, flat rectangular and arc-shaped ones are the mainstream, and these segments are joined together by bolts.
As a structure for joining the segments with this bolt, a joint plate having holes communicating with each other when the joint end surfaces of the segments are brought into contact with each other in the vicinity of the joint end surfaces of the segments is embedded. Generally, a structure is used in which a bolt is inserted into the hole portion and a nut is fastened and joined to the bolt. There is also a structure in which insert fittings which are nut members are embedded in the mutual segments, and bolts penetrating through the adjacent segments are fastened and joined together.
[0003]
[Problems to be solved by the invention]
However, in such a structure, the bolt is inserted into the hole formed in the joint end face of the joint at the construction site, and the nut is fastened to the bolt, or the bolt is fastened to the insert fitting embedded in the mutual segment. Therefore, there is a limit to shortening the assembly time because it requires extremely complicated work, and adaptation to automatic assembly by a robot is difficult. Furthermore, even when the secondary lining is omitted, the bolt box formed in the segment must be closed in order to install the bolts and nuts, and a new joint is aimed at speeding up construction and saving labor. The current situation is that there is an urgent need to develop the structure.
Furthermore, there has been a demand for a joining structure capable of reliably transmitting the fastening force to the entire segment when the segments are joined to each other and applying a large joining force to the joining end faces of these segments.
[0004]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a joining structure of segments that can be joined to each other very easily and reliably.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the segment joint structure according to claim 1 is a segment joint structure in which the joint end surfaces are joined to each other in the excavation hole so as to constitute a tunnel wall body. The segment is provided with a joint fitting on each joint end face, the joint fittings are connected to each other by a connection fitting, the joint fittings are provided to face each other, and the end portion is inward. It has a pair of hook-shaped locking portions that are bent locking pieces, and the connecting metal fittings are formed on both sides of the plate-like connecting metal body between the locking portions. An engaging portion having an engaging surface that fits into the space and engages with the locking piece portion is provided, and the joining end surfaces of the segments are abutted to each other in the engaging space of each joining metal fitting. While engaging the engaging parts on both sides By inserting the connecting fitting, the segments are joined to each other, and the engaging surface of the engaging portion of the connecting fitting is a tapered surface gradually approaching rearward in the insertion direction. The locking piece portion has a locking surface that engages with the engaging surface and is a tapered surface inclined in the same direction as the engaging surface, and the joining metal parts to be joined to each other meet the joining end surfaces of the segments. It is characterized in that a gap is formed between each other in a joined state in which the connecting metal fittings are arranged.
Thus, the joining brackets are joined to each other by the joining bracket by inserting the engaging portion of the joining bracket into the engagement space of the joining bracket in a state where the joining end surfaces of the segments are in contact with each other. They are joined together. Moreover, the fastening force of the joining metal fittings by the connection metal fittings is transmitted from the joining metal fittings to the segment, and the joining end surfaces of the segments are joined by a reliable joining force.
[0006]
The segment joint structure according to claim 2 is the segment joint structure according to claim 1, wherein the segment is made of concrete, and the joint metal is anchor anchor embedded in the concrete forming the segment. Are connected.
Thereby, the fastening force of the joining metal fittings by a connection metal fitting is transmitted to the concrete which forms a segment from an anchor reinforcement.
[0007]
The segment joining structure according to claim 3 is the segment joining structure according to claim 2, wherein a plurality of ribs are formed at intervals in the longitudinal direction of the anchor muscle.
Thereby, the fixation strength of the anchor bars to the concrete forming the segments is improved by the ribs formed on the anchor bars.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the joining structure of the segment of embodiment of this invention is demonstrated with figures.
1 and 2, reference numeral 1 denotes a segment. These segments 1 are made of concrete formed in a rectangular shape in plan view, and a ring constituting a tunnel wall body is constructed in the excavation hole by joining the joining end faces 1a in the circumferential direction of the segments 1 to each other. It has come to be. The tunnel wall is constructed by joining the rings together in the axial direction of the excavation hole.
[0009]
These segments 1 are formed with two rows of joining groove portions 1b in the thickness direction on the joining end surface 1a in the circumferential direction, and these joining groove portions 1b are provided with C-shaped joining metal fittings 2 in sectional view. The joining metal fittings 2 are connected to each other by a connecting metal fitting 3 having an I-shaped cross section.
[0010]
As shown in FIG. 3 and FIG. 4, the joining metal fitting 2 is formed by a pair of locking portions 5 formed in a bowl shape having locking pieces 4 at opposing positions. A space formed by the five members is an engagement space 7 in which the engaging portion 6 of the coupling fitting 3 is engaged.
Further, the locking surface 4 a formed by the inner surface of the locking piece portion 4 is a tapered surface that narrows the engagement space 7 in the insertion direction A of the connection fitting 3. That is, in the state where the joining end surfaces 1 a of the segments 1 are abutted with each other, the locking surfaces 4 a of the joining fittings 2 facing each other are tapered surfaces that gradually approach toward the rear in the insertion direction of the connecting fitting 3.
[0011]
Anchor bars 9 are connected to the joining metal fittings 2 at the rear ends thereof, and these anchor reinforcements 9 are embedded in the concrete C forming the segment 1, so that each joining metal fitting 2 is securely attached to the segment 1. It is fixed. The anchor bars 9 are formed with a plurality of ribs 10 at intervals along the length direction thereof, and the strength of fixing to the concrete C is further enhanced by the ribs 10.
[0012]
Moreover, these joining metal fittings 2 are fixed to the segment 1 at a position where a slight gap is formed when the joining end faces 1a of the respective segments 1 are brought into contact with each other.
That is, the end portions on the joining side of these joining fittings 2 are set to positions where they are slightly drawn from the joining end surfaces 1 a of the respective segments 1. The pull-in dimension T is T = about 0.5 mm. Therefore, when the joining end surfaces 1a of the segments 1 are brought into contact with each other, the gap S between the joining fittings 2 of the segments 1 is S = about 1 mm (S = 2T = 2 × 0.5).
[0013]
The connecting fitting 3 for connecting the joining fitting 2 is formed in an I-shaped cross section, and both engaging portions of the connecting fitting main body 8 are fitted into the engaging space 7 of the joining fitting 2 as described above. It is set to 6. The connecting metal fitting body 8 is formed thinner than the gap between the locking pieces 4 of the locking portion 5 constituting the joint fitting 2 and can be inserted therethrough. It is formed thicker than the gap. Further, the engaging surface 6 a formed on the engaging portion 6 of the connecting metal fitting 3 that comes into contact with and engages with the engaging surface 4 a of the engaging piece portion 4 of the joining metal fitting 2 is connected to the engaging surface 4 a of the joining metal fitting 2. Similarly, it is set as the taper surface which adjoins toward the insertion direction back.
[0014]
Next, the case where the segments 1 having the above structure are joined together by the connecting metal fitting 3 will be described.
In the case where the segments 1 are joined to each other by the connecting metal fitting 3, the joining end faces 1a of the segments 1 are first brought into contact with each other.
In this state, as shown in FIG. 5, the engaging portions 6 on both sides of the connecting metal fitting 3 are inserted so as to engage in the engaging spaces 7 formed in the respective joining metal fittings 2.
If it does in this way, the engaging part 6 of the connection metal fitting 3 will be inserted in the engagement space 7 of each joining metal fitting 2, and it will be engaged and connected.
[0015]
Thus, according to the joining structure of the said segment, the engaging part 6 of the connection metal fitting 3 is put into the engagement space 7 of the joining metal fitting 2 in the state which the joining end surfaces 1a of the segment 1 contact | abutted mutually. By inserting, the joining metal fittings 2 can be joined very easily by the connecting metal fittings 3 and the segments 1 can be joined together. In other words, compared to conventional fastening structures using bolts and nuts or fastening structures that fasten bolts to insert fittings, the labor required to join segments can be greatly reduced, and there is no bolt box or the like. Therefore, the work of closing the bolt box can be omitted.
[0016]
Moreover, since each joint fitting 2 is provided at a position where the gap S is formed when the joining end faces 1a of the segments 1 are brought into contact with each other, it is compared with the joining structure in which the joint fittings 2 are in contact with each other. Thus, the fastening force between the joining fittings 2 by the connecting fitting 3 can be reliably transmitted to the segments 1, and a certain joining force between the joining end faces 1 a of these segments 1 can be ensured.
[0017]
That is, when the joining metal fittings 2 are in contact with each other, the fastening force by the coupling metal fittings 3 is transmitted to each other through the joining metal fittings 2 that are in contact with each other. Since the gap S is formed between the metal fittings 2, the fastening force by the connecting metal fitting 2 is transmitted from the joining metal fitting 2 and the anchor bar 9 to the segment 1 and is transmitted via the joining end surface 1 a of the segment 1. Therefore, a reliable joining force is obtained between the joining end faces 1a of the segments 1.
[0018]
In addition, the fastening force between the joint fittings 2 by the connection fitting 3 can be reliably transmitted from the anchor bar 9 to the concrete C forming the segment 1, and thereby, the stickiness at each joint location due to the elasticity of the anchor bar 9 and the like. , Toughness can be improved.
In addition, the ribs 10 formed on the anchor bars 9 can significantly increase the anchoring strength of the anchor bars 9 to the concrete C forming the segment 1, thereby reliably transmitting the fastening force from the anchor bars 9 to the segment 1. Can be done.
[0019]
【The invention's effect】
As described above, according to the segment joining structure of the present invention, the following effects can be obtained.
According to the joining structure of the segment according to claim 1, by inserting the engaging portion of the connecting fitting into the engaging space of the joining fitting in a state where the joining end faces of the segments are in contact with each other, The joining metal fittings can be easily joined to each other by the coupling metal fittings, and the segments can be joined together. In other words, compared to conventional fastening structures using bolts and nuts or fastening structures that fasten bolts to insert fittings, the labor required to join segments can be greatly reduced, and there is no bolt box or the like. Therefore, the work of closing the bolt box can be omitted.
Moreover, since each joint fitting is provided at a position where a gap is formed when the joining end surfaces of the segments are brought into contact with each other, the joining by the joining fitting is compared with the joining structure in which the joining fittings are in contact with each other. The fastening force between the metal fittings can be reliably transmitted to the segments, and a reliable joining force between the joining end faces of these segments can be ensured.
[0020]
According to the joining structure of the segment according to claim 2, the fastening force between the joining fittings by the connecting fitting can be reliably transmitted from the anchor reinforcement to the concrete forming the segment. The stickiness and toughness at each joint location can be improved.
According to the joining structure of segments according to claim 3, the anchor strength of the anchor bars to the concrete forming the segments can be greatly increased by the ribs formed on the anchor bars, and the fastening force from the anchor bars to the segments Can be reliably transmitted.
[Brief description of the drawings]
FIG. 1 is a perspective view of a segment for explaining a joining structure of segments according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of segments joined to each other for explaining a joint structure of segments according to an embodiment of the present invention.
FIG. 3 is a longitudinal sectional view of a joining portion for explaining a joining structure of segments according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view of a joint portion for explaining a joint structure of segments according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view of a joining portion for explaining a joining structure of segments according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Segment 1a Joining end surface 3 Connecting metal fitting 4 Locking piece part 4a Locking surface 5 Locking part 6 Engaging part 7 Engaging space 8 Connecting metal fitting body 9 Anchor bar 10 Rib C Concrete S Gap

Claims (3)

In the excavation hole, it is joined in a state in which the joint end faces face each other, and is a joining structure of the segments constituting the tunnel wall body,
The segment is provided with a joint fitting on each joint end face, and these joint fittings are connected to each other by a connection fitting,
The joint fitting has a pair of hook-shaped locking portions provided to be opposed to each other, and having end portions bent inwardly,
The connecting metal fitting has engaging surfaces on both sides of a plate-like connecting metal fitting main body that engages with the engaging piece by engaging in an engaging space formed between the engaging parts. An engaging portion is provided,
In a state in which the joining end surfaces of the segments are abutted with each other, the segments are joined to each other by inserting the connecting fittings while fitting the engaging portions on both sides into the engaging spaces of the joining fittings. And
The engaging surface of the engaging part of the coupling metal is a tapered surface gradually approaching rearward in the insertion direction, and the engaging piece of the joining metal part has an engaging surface that engages with the engaging surface. It is a tapered surface inclined in the same direction as the engagement surface,
The joining structure for joining segments is characterized in that gaps are formed between the joining fittings that are joined to each other in a joining state in which the joining fittings are arranged by abutting the joining end faces of the segments. The segment joining structure according to claim 1, wherein the segment is made of concrete, and an anchor bar embedded in the concrete forming the segment is connected to the joining metal fitting. The segment joining structure according to claim 2, wherein a plurality of ribs are formed in the anchor bar at intervals in the longitudinal direction.

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