JP3787637B2 - Assembly bolt fall prevention device for mortise segment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mortise-attached assembly bolt drop prevention device for preventing a temporary fastening assembly bolt used when assembling a mortise segment to form a shield tunnel lining when the tunnel is used.
[0002]
[Prior art]
In general, shield tunnels are made by assembling concrete segments in a ring shape and extending the lining in order. Recently, tenons and tenon grooves that fit each other are formed on the joint end surface (joint surface between rings) on the tunnel axial direction side. However, a so-called tenoned segment with a tenoned segment has been developed in which the fitting is made to resist the shear load of the joint. In addition, a segment having a mortise and a mortise groove on the circumferential side joining end surface (inter-segment joining surface) of the segment has been developed.
[0003]
As shown in FIGS. 8 and 9, the mortise-attached segment is assembled by allowing the bolt insertion hole 4 to open through the joint surface 3a of the segment from the recess 2 formed on the inner peripheral side surface of one segment 1a. The anchor nut 5 is embedded in the joint surface 3b of the segment 1b, and the entire lining 7 is secured while temporarily fastening the assembly bolt 6 by passing the bolt insertion hole 4 through the recess 2 and screwing it into the anchor nut 5. I try to assemble it.
[0004]
FIG. 8 shows an inter-ring joint, and FIG. 9 shows an inter-segment joint.
[0005]
The assembly bolt 6 used here is not for maintaining the joint strength between the segments after assembly, and after the assembly is completed, its function is finished and unnecessary, and the lining is applied to the inner peripheral surface. It is used in a state where the inner peripheral side surface of the segment is exposed to the inner surface of the tunnel without performing the next lining.
[0006]
[Problems to be solved by the invention]
In conventional shield tunnels with mortise segments as described above, assembly bolts are not required after the lining is assembled, but it takes a lot of work to remove them, leaving them as is rather than removing them for reuse. It is left attached because it reduces costs.
[0007]
However, since this assembled bolt is normally exposed on the inner surface of the tunnel, it can be considered that it will loosen due to vibration and fall off when the tunnel is used.
[0008]
SUMMARY OF THE INVENTION In view of such circumstances, the present invention aims to provide an assembly bolt drop prevention device for a tenoned segment that effectively prevents the assembly bolt from dropping off in a tunnel that is mainly used with the inner peripheral side surface of the segment exposed. It was made as.
[0009]
[Means for Solving the Problems]
The feature of the present invention for solving the conventional problems as described above and achieving the intended purpose is that the tenon and tenon grooves formed on the joint surface around the segments are fitted to each other so that the segments are joined to each other. Assemble between adjacent joint surfaces by screwing an assembly bolt into an anchor nut embedded in the joint surface of the other segment through a bolt insertion hole penetrating from the concave portion of the inner peripheral surface of one segment to the joint surface of the segment. In the shield tunnel lining, the cylinder is embedded with the tip opening exposed outside the opening of the bolt insertion hole in the recess on the inner peripheral side of the segment , and the bolt retaining protrusion can be freely inserted into and removed from the cylinder. And after the assembly bolts are tightened, the bolt retaining protrusions are projected to the bolt head extension position .
[0010]
In addition, forming the cylinder tip opening smaller than the inner diameter of the cylinder portion, slidable in the cylinder, and provided with a flange for retaining the larger diameter than the tip opening at the cylinder inner end of the bolt retaining protrusion, and It is preferable that a female screw is provided on the inner surface of the front end opening of the cylinder, and a plug body for preventing the protrusion of the bolt retaining projection is detachably screwed into the female screw.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same part as the prior art example mentioned above, and duplication description is abbreviate | omitted.
[0012]
In the figure, reference numeral 10 denotes an assembled bolt drop prevention device according to the present invention. This device 10 has a cylinder 11 embedded in a segment 1a, and a bolt retaining projection 12 housed in the cylinder 11 and having a distal end side that is freely accessible through a cylinder opening.
[0013]
The cylinder 11 has an opening portion 11 b having a diameter smaller than the inner diameter of the cylindrical portion on one end side of the cylindrical portion 11 a, and the other end side is closed by a bottom lid 13. A female screw is formed on the inner peripheral surface of the opening 11b, and the plug body 14 is screwed into the female screw.
[0014]
A bolt 12 retaining projection 12 is housed in the cylinder 11 such that the distal end side 12a protrudes from the opening 11b of the cylinder 11, and the end of the projection 12 on the inner side of the cylinder passes through the cylindrical portion 11a of the cylinder 11 in the axial direction. The retaining flange 12b having a larger diameter than the opening 11b is integrally formed, and the entire body is accommodated in the cylinder 11 with the plug 14 fitted in the opening.
[0015]
The cylinder 11 is embedded in an arrangement in which the opening 11b is exposed on the surface of the recess 2 formed on the inner peripheral surface of the segment, and the bolt head 5a in a state where the assembly bolt 6 is screwed into the anchor nut 5 and tightened. It is installed at a position where the protrusion 12 protrudes on the extension side.
[0016]
When installing the assembled bolt drop prevention device configured as described above, as shown in FIG. 7, the plug 14 of the cylinder opening 11b is removed, and the bolt penetrated through the mold 15 for forming the concave portion 2 of the segment therethrough. 16 is screwed into the opening 11b to be fixed to the mold member 15, and concrete is cast to form a segment. As a result, the cylinder 11 is embedded with the opening 11b exposed at the surface of the concave portion 2 of the segment.
[0017]
Then, the bolts 16 are removed, the segment mold is removed, and the segments are carried into the tunnel with the plugs 14 screwed into the openings 11b as shown in FIG. Connect the segments and assemble the lining. After the assembly is completed in this way, the plug 14 is removed.
[0018]
As a result, at the position where the cylinder opening 11b faces downward, the protrusion 12 protrudes by its own weight as shown in FIGS. 3, 4 and 5, and protrudes to the extended side of the assembly bolt head 6a. Even if it is loosened, it comes into contact with the protrusion 12 and is prevented from falling off.
[0019]
Note that a protrusion pushing means (not shown) such as a coil spring may be housed in the back of the flange in the cylinder 11 so that the protrusion 12 protrudes reliably.
[0020]
However, when there is no protrusion pushing means, the protrusion 12 remains in the cylinder 11 under its own weight when the cylinder opening 11a is horizontal to upward and the protrusion 12 does not protrude under its own weight. Then, the assembly bolt does not fall off, and it is not always necessary because it does not need to be prevented from coming off.
[0021]
【The invention's effect】
As described above, the assembly bolt drop-off prevention device for the tenoned segment according to the present invention is such that the tenon and tenon grooves formed on the joint surface around the segment are fitted to each other and the segments are joined to each other, and between the joint surfaces adjacent to each other. A shield tunnel in which an assembly bolt is screwed into an anchor nut embedded in the joint surface of the other segment through a bolt insertion hole penetrating from the recess on the inner peripheral surface of one segment to the joint surface of the segment In the lining, the bolt retaining protrusion protrudes from the bolt insertion hole opening of the concave portion on the inner peripheral side surface of the segment to the head extension position of the assembly bolt inserted through the bolt insertion hole. Therefore, even if the assembly bolt used for temporary fixing at the time of assembly is loosened, it will not fall out, resulting in danger to traffic. It is eliminated.
[0022]
Also, the cylinder is embedded with the tip opening exposed in the recess on the inner peripheral side surface of the segment, and a bolt retaining protrusion is removably accommodated in the cylinder. After the assembly bolt is fastened, the bolt retaining protrusion is inserted into the cylinder. By projecting to the bolt head extension position, it is easily installed by insert molding integrally at the time of manufacturing the segment, and it is prevented from falling off without requiring special troublesome work at the site.
[0023]
Furthermore, the cylinder's tip opening is formed smaller than the inner diameter of the cylinder, and the cylinder can be slid and provided with a flange with a larger diameter than the tip opening to prevent the bolt from falling off. Projections at places where prevention is required can be projected by their own weight, and workability is good.
[0024]
Furthermore, by providing a female screw on the inner surface of the opening at the tip of the cylinder and removably screwing a stopper for preventing the protrusion of the bolt retaining projection into the female screw, it is possible to attach to the mold material during insert molding to the segment. It can be easily supported by a mounting bolt that penetrates the mold material.
[Brief description of the drawings]
FIG. 1 is a half cross-sectional view in the tunnel radial direction of a lining by a tenoned segment installed with the apparatus of the present invention.
FIG. 2 is a partial cross-sectional view of the upper part of the lining in the tunnel axis direction.
FIG. 3 is an enlarged cross-sectional view showing an inter-ring joint of the same lining.
FIG. 4 is an enlarged sectional view showing a joint part between the segments.
FIG. 5 is an enlarged cross-sectional view of the bolt drop-off device used in the example shown in FIGS.
FIG. 6 is an enlarged cross-sectional view showing a state when the assembled bolt is tightened.
FIG. 7 is an enlarged cross-sectional view showing a state in which concrete is placed while being supported by the same mold material.
FIG. 8 is a cross-sectional view showing an inter-ring joint of a lining by a conventional tenoned segment.
FIG. 9 is a cross-sectional view showing a joint portion between the segments.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a, 1b Segment 2 Recessed part 3a, 3b Joint surface 4 Bolt insertion hole 5 Anchor nut 5a Bolt head 6 Assembly bolt 6a Assembly bolt head 7 Covering 10 Assembly bolt fall prevention device 11 Cylinder 11a Cylindrical part 11b Opening part 12 Bolt removal Stop projection 12a Tip side 12b Retaining flange 13 Bottom cover 14 Plug body 15 Mold material 16 Bolt

Claims (3)

The tenon and tenon groove formed on the joint surface around the segment are fitted to each other to join the segments, and the adjacent joint surfaces are penetrated from the concave portion on the inner peripheral side surface of one segment to the joint surface of the segment. In the shield tunnel lining that is assembled by screwing the assembly bolt into the anchor nut embedded in the joint surface of the other segment through the bolt insertion hole,
Outside the bolt insertion hole opening of the concave portion on the inner peripheral side surface of the segment, a tip opening is exposed and a cylinder is embedded, and a bolt retaining protrusion is housed in the cylinder so that it can be freely inserted and removed. An assembly bolt drop prevention device for a tenoned segment, characterized in that a bolt retaining protrusion is projected to the bolt head extension position . The cylinder front end opening is formed smaller than the inner diameter of the cylinder part, and a flange for preventing a larger diameter than the front end opening and slidable in the cylinder is provided at the inner end of the cylinder of the bolt retaining protrusion. Assembling bolt fall prevention device for mortise segment as described. 3. An assembly bolt for a mortise segment according to claim 1 or 2, wherein a female screw is provided on the inner surface of the tip opening of the cylinder, and a stopper for preventing protrusion of the bolt retaining protrusion is detachably screwed into the female screw. Fall-off prevention device.

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