JP7307438B2 - Tunnel lining rebar support device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for supporting reinforcing bars of a secondary lining of a tunnel (lining reinforcing bars).

For example, in mountain tunnels constructed by the NATM (New Austrian Tunneling Method) method, the primary lining is constructed by erecting arch-shaped steel shoring along the excavated surface of the ground and spraying shotcrete on the excavated surface. Then, a secondary lining of reinforced concrete structure will be constructed on the inner circumference side of the primary lining with a waterproof sheet interposed.

The secondary lining is constructed by pouring concrete with the rebar assemblies arranged along the inner circumference of the primary lining. Prior to pouring concrete, the rebar assembly is supported using a number of lining rebar support devices distributed about the inner circumference of the primary lining.

As disclosed in FIG. 5 of Patent Document 1, FIGS. 9 to 15 of Patent Document 2, Patent Document 3, and the like, a general lining reinforcing bar support device is used for fixing a waterproof sheet to a primary lining. A fixing structure and an anchor rod having a base end screwed into the fixing structure and extending radially inward of the tunnel are provided, and the reinforcing bars of the reinforcing bar assembly (lining reinforcing bars) are connected to the anchor rods. .

JP-A-2000-352299 JP 2004-150117 A JP 2006-70656 A

In order to ensure the concrete cover thickness of the secondary lining, the position of the rebar assembly is important. It is not easy to connect while Also, it is not easy to adjust the position after connecting the lining reinforcing bars to the anchor rods.

In order to solve the above problems, the present invention provides a fixing structure for fixing a waterproof sheet to the inner circumference of a primary lining of a tunnel, and an anchor structure connected to the fixing structure and extending radially inward of the tunnel from the fixing structure. and a device for supporting lining rebars constituting a rebar assembly of a secondary lining by the anchor structure,
The anchor structure includes an anchor rod having a base end connected to the fixing structure and extending radially inward of the tunnel; and an adjusting nut that is screwed on the anchor rod to the distal end side of the mounting position of the connecting structure to adjust the position of the connecting structure.
According to the above configuration, the position of the connecting structure can be easily adjusted by turning the adjustment nut, and thus the position of the reinforcing bar assembly can be adjusted. In particular, even after the reinforcing bar assembly is connected to the lining reinforcing bar support device, the position of the reinforcing bar assembly can be easily adjusted by rotating the nut.

In one aspect of the present invention, the anchor structure further includes a support tube that is attached to the anchor rod and is slidable in the axial direction of the anchor rod, and the connection structure is attached to the support tube and is attached to the support tube. The adjusting nut is screwed onto the anchor rod toward the distal end of the support tube, and the position of the connecting structure can be adjusted by adjusting the position of the support tube. Adjust.
According to the above configuration, since the position of the connecting structure is adjusted via the support tube slidably attached to the anchor rod, the position adjustment work can be performed more easily.

In the aspect described above, preferably, the reinforcing bar assembly includes an outer reinforcing bar assembly arranged radially outside the tunnel and an inner reinforcing bar assembly arranged radially inside the tunnel, and the connection structure comprises: a first connection structure connecting the lining reinforcing bars of the outer reinforcing bar assembly; and a second connecting structure connecting the lining reinforcing bars of the inner reinforcing bar assembly, wherein the first connecting structure is the support cylinder. and the second connecting structure is sandwiched between the support tube and the adjusting nut.

In the aspect described above, preferably, the reinforcing bar assembly includes an outer reinforcing bar assembly arranged radially outside the tunnel and an inner reinforcing bar assembly arranged radially inside the tunnel, and the connection structure comprises: a first connection structure connecting the lining reinforcing bars of the outer reinforcing bar assembly; and a second connecting structure connecting the lining reinforcing bars of the inner reinforcing bar assembly, wherein the first connecting structure and the second connecting structure. Connecting structures are attached to the support tube at intervals.

In the above-mentioned other aspect, preferably, the connecting fitting has a base portion having a female thread portion and a pair of parallel hook portions extending from both side edges of the base portion, and the lining reinforcing bars are inserted into the hook portions. The base portion and the pair of hook portions constitute the insertion portion, and the connection structure further includes a tightening screw, the tightening screw being screwed into the female thread portion of the base portion and having a distal end of the anchor. hits the circumference of the rod.

Preferably, the anchoring structure has a long nut arranged inside the waterproof sheet and protruding radially inward of the tunnel, and the base end of the anchor rod adjusts the screwing depth of the long nut. Allowed and screwed together.
According to the above configuration, the projection length of the anchor rod from the fixing structure can be adjusted.

According to the lining reinforcing bar supporting device of the present invention, it is possible to easily adjust the position of the lining reinforcing bars of a tunnel.

1 is a cross-sectional view showing a schematic structure of a tunnel constructed using a lining reinforcing bar support device according to the present invention; FIG. FIG. 2 is an enlarged vertical cross-sectional view along line II-II of FIG. 1, showing the lining reinforcing bar support device according to the first embodiment in a state before secondary lining concrete is cast; It is the side view which looked at the principal part of the said lining reinforcing-bar support apparatus from the III direction in FIG. It is a figure equivalent to Drawing 3 showing a lining reinforcing bar support device concerning a 2nd embodiment. It is a longitudinal cross-sectional view which shows the connection structure of the lining reinforcing-bar support apparatus which concerns on 3rd Embodiment. FIG. 11 is a side view showing a second connection structure that connects the lining reinforcing bars of the inner reinforcing bar assembly in the lining reinforcing bar supporting device according to the fourth embodiment. It is a side view which shows the connection structure of the lining reinforcing-bar support apparatus which concerns on 5th Embodiment. FIG. 10 is a view equivalent to FIG. 2 showing a different fixing structure in the lining reinforcing bar support device according to the sixth embodiment. FIG. 21 is a vertical cross-sectional view showing a still different fixing structure in the lining reinforcing bar support device according to the seventh embodiment. FIG. 20 is a vertical cross-sectional view showing a still different fixing structure in the lining reinforcing bar support device according to the eighth embodiment.

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG.
As shown in FIG. 1, the NATM tunnel consists of a primary lining 2 constructed on the excavated surface 1a of the natural ground 1, and a secondary lining 6 constructed on the inner circumference of the primary lining 2 via a waterproof sheet 5. and
The primary lining 2 is constructed by H-shaped steel shorings 3 erected in an arch shape along the excavation surface 1a at intervals in the longitudinal direction of the tunnel and concrete 4 sprayed on the excavation surface 1a. there is
The waterproof sheet 5 is made of a resin sheet such as EVA, and serves to prevent water from the natural ground 1 from entering the secondary lining 6 through the primary lining 2 .

The secondary lining 6 is constructed with concrete 7 and reinforcing bar assemblies 8 and 9 embedded in this concrete 7 .
A reinforcing bar assembly 8 on the radially outer side of the tunnel (on the side of the primary lining 2) (hereinafter referred to as an outer reinforcing bar assembly) and a reinforcing bar assembly 9 on the radially inner side of the tunnel (hereinafter referred to as an inner reinforcing bar assembly) , are spaced apart radially of the tunnel. The reinforcing bar assemblies 8 and 9 are respectively a large number of reinforcing bars 8a and 9a (lining reinforcing bars) extending in the longitudinal direction of the tunnel (direction perpendicular to the paper surface of FIG. 1) and a large number of reinforcing bars extending curvedly in the circumferential direction of the tunnel. 8b and 9b (lining reinforcing bars) are bound at their intersections to form a lattice (net).

Prior to placing the concrete 7 of the secondary lining 6, the waterproof sheet 5 is fixed to the inner periphery of the primary lining 2 by a number of lining reinforcing bar support devices A, and the reinforcing bar assemblies 8 and 9 are attached to the primary lining 2. To support. A number of lining rebar support devices A are spaced circumferentially and longitudinally of the tunnel.

As shown in FIGS. 2 and 3, each lining reinforcing bar support device A includes a fixing structure 10 and an elongated anchor structure 20 connected to the fixing structure 10 and extending radially inward of the tunnel. The fixing structure 10 plays a role of fixing the waterproof sheet 5 to the primary lining 2 and holding the anchor structure 20 . Anchor structure 20 serves to support inner rebar assembly 8 and outer rebar assembly 9 .

The fixing structure 10 has a receiving metal fitting 11 arranged outside the waterproof sheet 5 , an engaging metal fitting 12 arranged inside the waterproof sheet 5 , a push screw 13 and a long nut 14 .
The receiving metal fitting 11 has a base portion 11a and a pair of receiving pieces 11b connected to both side edges of the base portion 11a and inclined so as to approach each other. Fixed. The engaging metal fittings 12 include a base portion 12a, a pair of leg portions 12b connected to both side edges of the base portion 12a and inclined so as to approach each other toward the tip, and a pair of legs projecting in opposite directions from the tip of the pair of leg portions 12b. and an engaging piece 12c. The pair of legs 12b are closer than the position shown in FIG. 2 in the natural state. A nut 12n (female screw portion) is fixed to the base portion 12a of the engaging metal fitting 12 and arranged between the pair of leg portions 12b. A push screw 13 is screwed onto the nut 12n.

With the waterproof sheet 5 covering the receiving metal fitting 11, after the engaging metal fitting 12 is pushed toward the receiving metal fitting 11 through the waterproof sheet 5, a tool hooking portion consisting of a hexagonal hole formed in the end face of the push-in screw 13 is formed. By inserting a tool into 13a and screwing in the push screw 13, the pair of leg portions 12b of the engaging fitting 12 are spread apart. As a result, the pair of engaging pieces 12c are engaged with the pair of receiving pieces 11b of the receiving fitting 11 through the waterproof sheet 5. As shown in FIG. In this way, the waterproof sheet 5 can be fixed to the shoring 3 without damaging it.
In the fixed state of the waterproof sheet 5, the push-in screw 13 protrudes radially inward of the tunnel from the base portion 12a of the engaging metal fitting 12, and a long nut 14 is screwed to the projecting end, preferably in a screwed state. is crimped to the push-in screw 13. The push screw 13 and the long nut 14 may be integrated by welding via a metal plate.

The anchor structure 20 includes an anchor rod 22 whose proximal end is screwed into the long nut 14 of the fixing structure 10 , a support cylinder 23 fitted to the anchor rod 22 , and a distal end of the anchor rod 22 . a connecting structure 30 (first connecting structure) that connects the outer reinforcing bar assembly 8; and a connecting structure 40 (second connecting structure) that connects the inner reinforcing bar assembly 9.

In this embodiment, the anchor rod 22 has male threads over its entire length, but may have male threads only at both ends. The tip of the anchor rod 22 is formed with a tool hooking portion 22a having a hexagonal cross section for hooking a tool when screwing the long nut 14 thereon.
The support tube 23 is slidable in the axial direction of the anchor rod 22 . The adjustment nut 24 is arranged on the distal end side of the support cylinder 23 .

The connecting structure 30 has a connecting fitting 31 formed by bending a metal plate and a tightening screw 35 . The connecting fitting 31 has a base portion 32 and a pair of parallel plate-shaped hook portions 33 extending from both side edges of the base portion 32 at right angles. The insertion portion 34 is configured by the base portion 32 and the portions of the pair of hook portions 33 near the base portion 32 .
A nut 32a (female threaded portion) is fixed to the inner surface of the base portion 32, and a tightening screw 35 is screwed into the nut 32a.

The support tube 23 is inserted through the insertion portion 34 of the connecting fitting 31 , the reinforcing bars 8 a of the outer reinforcing bar assembly 8 are fitted to the pair of hook portions 33 , and in this state, the tightening screw 35 is screwed into the support tube 23 . By pressing against the peripheral surface, the outer reinforcing bar assembly 8 is connected to the support tube 23 .

The connecting structure 40 has a connecting fitting 41 formed by bending a metal plate and a tightening screw 45 . The connecting metal fitting 41 includes a connecting plate portion 42 having an insertion hole 42a (insertion portion), a curved holding portion 43 connected to one side of the connecting plate portion 42, and a connecting plate portion 41 connected to both sides of the holding portion 43. and a pair of parallel hook portions 44 extending in orthogonal directions. A tightening screw 45 is screwed into the female screw portion of the pressing portion 43 .

The anchor rod 22 is passed through the insertion hole 42 a of the connecting fitting 40 , the connecting plate portion 41 is sandwiched between the support cylinder 23 and the adjusting nut 24 , the reinforcing bars 9 a of the inner reinforcing bar assembly 9 are inserted into the pair of hook portions 44 , and the pressing portion 43 is inserted. The inner reinforcing bar assembly 9 is connected to the anchor rod 22 by inserting the reinforcing bar 9b into the anchor rod 22, screwing in the tightening screw 45, and pressing the tip of the reinforcing bar 9b against the reinforcing bar 9b.

According to the above configuration, the projection length of the anchor rod 22 from the fixing structure 10 can be adjusted by adjusting the screwing depth of the anchor rod 22 with respect to the long nut 14 . In addition, in the connection structure 30, the position of the connection fitting 31 can be adjusted with respect to the support cylinder 23 in the axial direction of the anchor rod 22 with the tightening screw 35 loosened. 9 can be adjusted as appropriate.

By turning the adjusting nut 24, the position of the support tube 23 can be adjusted along the anchor rod 22, and thus the position of the connecting structure 30 connected to the support tube 23 can be adjusted. At the same time, the connecting fitting 40 can also be position-adjusted along the anchor rod 22 while being held between the support tube 23 and the adjusting nut 24 . Since adjustment is performed by rotating the adjustment nut 24, not only before the reinforcing bar assemblies 8 and 9 are connected to the anchor structure A by the connecting structures 30 and 40, but also after connecting the reinforcing bar assemblies 8 and 9, the comparison is made. The position can be easily adjusted with a relatively small force.
In particular, since the support tube 23 slides with respect to the anchor rod 22, the position adjustment work of the connection structure 30 can be performed more smoothly.

Next, another embodiment of the present invention will be described. In the following embodiments, constituent parts corresponding to those in the preceding embodiments are denoted by the same reference numerals or similar reference numerals, and detailed description thereof will be omitted.

In the second embodiment shown in FIG. 4 , a connection structure 30A (second connection structure) that connects the inner reinforcing bar assemblies 9 is also attached to the support tube 23 . This connection structure 30A has the same configuration as the connection structure 30 (first connection structure) that connects the outer reinforcing bar assemblies 8 . In this embodiment, the adjustment nut 24 abuts the end face of the support tube 23 directly or via a washer (not shown). In the second embodiment, since the two connecting structures 30 and 30A are attached to the support tube 23, position adjustment by the adjusting nut 24 can be performed more smoothly.

In the third embodiment shown in FIG. 5, a connecting structure 50 having a different form is used. This connecting structure 50 can be used instead of the connecting structure 30 of the first embodiment or the connecting structures 30, 30A of the second embodiment. This connecting structure 50 has a connecting fitting 51 and a tightening screw 55 formed by bending a metal plate. The connecting fitting 51 has a base portion 52 formed with a female threaded portion 52a and a pair of engaging portions 53 extending from both side edges of the base portion 52 in parallel with each other. The pair of engaging portions 53 are formed with insertion holes 53a.

The support tube 23 is passed through the insertion holes 53a of the pair of engaging portions 53 of the connecting fitting 51, and the reinforcing bar 8a of the outer reinforcing bar assembly 8, for example, is inserted into the space between the base portion 52 and the pair of engaging portions 53 and the support tube 23. By tightening the tightening screw 55 screwed into the female threaded portion 52a of the base portion 52 and pressing the tip of the tightening screw 55 against the peripheral surface of the reinforcing bar 8a, the reinforcing bar 8a strongly hits the support cylinder 23. concatenated.

In the fourth embodiment shown in FIG. 6, a connecting structure 30B for the inner reinforcing bar assembly 9 has the same configuration as the connecting structures 30, 30A of the first and second embodiments, and includes a connecting fitting 31 and a tightening screw. 35. However, the distance between the pair of hook portions 33 of the connecting fitting 31 is slightly larger than the outer diameter of the anchor rod 22 and smaller than the outer diameter of the support tube 23 . In this embodiment, a pair of hook portions 33 are sandwiched between the support cylinder 23 and the adjustment nut 24. As shown in FIG. A washer 39 is interposed between the hook portion 33 and the adjusting nut 24 .

When adjusting the position of the connecting structure 30B together with the support tube 23 to which the connecting structure (not shown) for the outer reinforcing bar assembly is attached, the tightening screw 35 is loosened beforehand. After the position adjustment by rotating the adjustment nut 24 is completed, the tightening screw 35 is tightened and the tip thereof is pressed against the peripheral surface of the anchor rod 22, thereby strongly pressing the anchor rod 22 and the reinforcing bar 9a.

In the fifth embodiment shown in FIG. 7, the reinforcing bars 9a are connected to the anchor rods 22 only by the connection structure 30C without using the support tube 23. As shown in FIG. 30 C of this connection structure are the same structures as the connection structure 30B of 4th Embodiment. If two connection structures 30C connect the outer rebar assembly 8 and the inner rebar assembly 9 to the anchor lock 22, an adjustment nut 24 is placed on each connection structure 30C. The position adjustment of the connection structure 30C by rotating the adjustment nut 24 and the connection between the anchor rod 22 and the reinforcing bar 9a by the tightening screw 35 are the same as in the fourth embodiment.

Embodiments using different fusing structures will now be described. These anchor structures can be combined with any of the anchor structures of the first to fifth embodiments.
In the fixing structure 10A of the sixth embodiment shown in FIG. 8, the base end portion of the anchor rod 22 is screwed into the nut 12n of the engaging fitting 12 without using the push screw 13 and the long nut 14 of the first embodiment. there is By spreading the pair of leg portions 12 b of the engaging fitting 12 with the base end portion of the anchor rod 22 , the pair of engaging pieces 12 c are engaged with the receiving fitting 11 . With this configuration, the length of protrusion of the anchor rod 22 cannot be adjusted, but the number of parts of the anchoring structure 10A can be reduced.

A fixing structure 60 according to the seventh embodiment shown in FIG. The bracket 61 has a female threaded portion 61a, is arranged outside the waterproof sheet 5, and is fixed to the shoring 3 of the first lining 2 by welding. The pressing plate 62 is arranged inside the waterproof sheet 5 and faces the receiving metal fitting 61 with the waterproof sheet 5 interposed therebetween. The through bolt 63 passes through the pressing plate 62 and the waterproof sheet 5 and is screwed into the female threaded portion 61 a of the receiving metal fitting 61 . The through bolt 63 protrudes from the pressing plate 62, and a long nut 64 is screwed to the projecting end. By tightening the long nut 64 , the waterproof sheet 5 is sandwiched between the pressing plate 61 and the receiving metal fitting 61 . The base end of the anchor rod 22 is screwed into the long nut 64 so that the screwing depth can be adjusted.

A fixing structure 60A of the eighth embodiment shown in FIG. 10 uses a receiving metal fitting 61 and a pressing plate 62 similar to those of the seventh embodiment, but does not use a through bolt 63 and a long nut 64. As shown in FIG. In this embodiment, the base end portion of the anchor rod 22 passes through the retainer plate 62 and the waterproof sheet 5 and is screwed into the female screw portion 61a of the receiving metal fitting 61 . A fixing nut 65 is screwed onto the anchor bolt 22 , and by tightening the fixing nut 65 toward the pressing plate 62 , the waterproof sheet 5 is sandwiched between the pressing plate 62 and the bracket 61 .

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the invention.
The connection structure may be fixed to the support tube so that its position cannot be adjusted. In this case, the connection structure may be composed of short reinforcing bars.
In the above embodiment, the reinforcing bar assembly of the secondary lining has a two-layer structure including the outer reinforcing bar assembly 8 and the inner reinforcing bar assembly 9, but it may have a single layer structure.
In the above embodiment, the connecting structure connects the reinforcing bars extending in the longitudinal direction of the tunnel in the reinforcing bar assembly, but may also connect the reinforcing bars extending in the circumferential direction.
The anchorage structure may anchor the tarpaulin at locations other than the shoring in the primary lining.

INDUSTRIAL APPLICABILITY The present invention is applicable to construction of tunnels.

2 Primary lining 5 Waterproof sheet 6 Secondary lining 7 Concrete 8, 9 Reinforcement assembly 8a, 8b, 9a, 9b Reinforcing bar (lining reinforcing bar)
10, 10A, 60, 60A Fixing structure 14, 64 Long nut 20 Anchor structure 22 Anchor rod 23 Support cylinder 24 Adjusting nut 30, 30A, 30B, 30C Connection structure 31 Connection metal fitting 32 Base 32a Nut (female screw part)
33 hook portion 34 insertion portion 35 tightening screw 40 connection structure 41 connection fitting 42 connection plate portion 44 hook portion A lining reinforcing bar support device

Claims (5)

a fixing structure for fixing a waterproof sheet to the inner periphery of the primary lining of the tunnel; and an anchor structure connected to the fixing structure and extending radially inward of the tunnel from the fixing structure, wherein the anchor structure In the device for supporting the lining reinforcing bars that constitute the reinforcing bar assembly of the next lining,
The anchor structure is
an anchor rod having a proximal end connected to the anchoring structure and extending radially inwardly of the tunnel;
a support cylinder mounted on the anchor rod and slidable in the axial direction of the anchor rod;
a connection structure that is attached to the support tube and connects the lining reinforcing bars;
an adjustment nut that is screwed onto the anchor rod toward the distal end of the support tube and adjusts the position of the connection structure by adjusting the position of the support tube;
with
The connection structure has a connection fitting whose position can be adjusted in the axial direction with respect to the support cylinder, and a tightening screw, and the connection fitting is a portion engaged with one of the lining reinforcing bars and the support cylinder. including
The tightening screw is screwed into the connecting fitting, and tightened with the tip thereof in contact with the other of the lining reinforcing bar and the supporting tube, so that the lining reinforcing bar and the supporting tube are in contact with each other. A tunnel lining reinforcing bar support device , characterized by being connected . wherein the rebar assemblies include an outer rebar assembly positioned radially outward of the tunnel and an inner rebar assembly positioned radially inward of the tunnel;
a first connecting structure as the connecting structure attached to the support cylinder and connecting the lining reinforcing bars of the outer reinforcing bar assembly;
a second connection structure sandwiched between the support tube and the adjustment nut to connect the lining rebars of the inner rebar assembly;
The tunnel lining reinforcing bar support device according to claim 1 , characterized by comprising : The second connection structure includes a connection plate portion having an insertion hole, and a portion connected to the connection plate portion and connecting the lining reinforcing bars of the inner reinforcing bar assembly, wherein the connection plate portion extends into the insertion hole. 3. The lining reinforcing bar support device according to claim 2, wherein the anchor rod is inserted and sandwiched between the support tube and the adjusting nut. wherein the rebar assemblies include an outer rebar assembly positioned radially outward of the tunnel and an inner rebar assembly positioned radially inward of the tunnel;
wherein the connecting structure includes a first connecting structure connecting the lining reinforcing bars of the outer reinforcing bar assembly and a second connecting structure connecting the lining reinforcing bars of the inner reinforcing bar assembly;
2. The tunnel lining reinforcing bar supporting device according to claim 1 , wherein the first connecting structure and the second connecting structure are attached to the support tube with a space therebetween. The fixing structure has a long nut that is arranged inside the waterproof sheet and protrudes inward in the radial direction of the tunnel, and the base end of the anchor rod is screwed into the long nut so that the depth of screwing can be adjusted. The tunnel lining reinforcing bar support device according to any one of claims 1 to 4, characterized in that it is screwed.

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