JP6302364B2 - Cable bolt fixing structure, cable bolt fixing method, and anchor bolt fixing structure - Google Patents

Description

  The present invention relates to a cable bolt fixing structure, a cable bolt fixing method, and an anchor bolt fixing structure.

  The cable bolt is not tensioned at the time of installation, and a tensile force appears only when displacement occurs due to loosening of the bedrock at the installation site. In the fixing structure using a wedge at the end of the cable bolt, there is a possibility that the wedge will loosen because the strong gripping force of the wedge against the cable bolt is not sufficient when the cable bolt is not pulled. is there. Therefore, conventionally, a cable bolt fixing structure described in Patent Document 1 has been proposed so that the loosened wedge does not fall off. In this fixing structure, an anchor plate and a socket portion are disposed at the rear end portion of the cable bolt, and a wedge is inserted between the cable bolt that passes through the socket portion and the inner wall surface of the socket portion. In order to prevent the wedge from falling off, the rear end surface of the wedge is pressed by a pressing member attached to the outer surface of the socket portion.

JP 2003-314199 A

  In the cable bolt, the wedge may be loosened even during the construction of the fixing structure. According to the fixing structure of Patent Document 1, for example, in the process before attaching the pressing member, there is a possibility that the loose wedge may fall off from the socket portion. Therefore, it is necessary to take another measure to prevent the wedge from falling during construction. Become. Further, in this type of cable bolt, since the rear end portion of the cable bolt includes a cable cut surface, some kind of rust prevention treatment is necessary. In Patent Document 1, it is necessary to spend time and effort on the rust prevention treatment of the rear end portion of the cable bolt that is finally exposed.

  Accordingly, the present invention reduces the possibility of the wedge falling during construction, and can easily perform the rust prevention treatment of the anchor bolt, the fixing method of the cable bolt, and the fixing structure of the anchor bolt. The purpose is to provide.

  The fixing structure of the cable bolt according to the present invention includes a bolt hole drilled in a bolt installation surface, a cable bolt having a distal end inserted into the bolt hole and protruding rearward from the bolt installation surface, and a bolt so as to embed the cable bolt A filling material filled in the hole, a plate through which the cable bolt is inserted and abutted against the bolt installation surface, a socket portion installed behind the plate and through which the cable bolt is inserted, an inner wall surface of the socket portion and the cable bolt And the socket portion has a recess for storing the rear end portion of the cable bolt protruding rearward from the wedge, and at least a part of the socket portion is fitted inside the recess. In addition, a cap that closes the recess and covers the rear end surface of the cable bolt is attached to the rear end of the socket portion. The features.

  According to this fixing structure, the rear end portion of the cable bolt protruding rearward from the wedge is housed in the recess, and the inside of the recess is closed by the cap. Therefore, the rear end portion of the cable bolt can be closed in the recess by a simple operation such as attaching a cap to the rear end of the socket portion, and an antirust effect can be obtained. Further, even when the wedge is loosened and separated from the cable bolt in the step before the cap is attached, the wedge is likely to stay in the recess of the socket portion and the possibility of falling downward is reduced.

  Further, the cap may have a male screw portion that is screwed into a female screw portion formed on the inner wall surface of the concave portion, and the wedge may be pressed forward by the advance of the cap screwed into the concave portion. According to this configuration, the wedge is firmly caught between the cable and the socket portion by pressing from the cap, so that loosening of the wedge is suppressed.

  In addition, the cable bolt fixing structure of the present invention may further include an inner sleeve that is sandwiched between the cap and the wedge in the recess and through which the rear end portion of the cable bolt is inserted.

  In that case, the inner sleeve may have a flange provided at the front end and abutting against the rear end surface of the wedge. According to this configuration, since the rear end surface of the wedge is uniformly pressed by the flange, the wedge is inserted in a correct posture, and the function of gripping the cable bolt by the wedge is correctly exhibited. In addition, the gap between the inner wall surface of the socket portion and the inner sleeve can be widened at the rear portion of the flange, so that, for example, the operator's hand can easily enter from this gap, and the worker can You can check the condition by touching it with your hand.

  The cable bolt fixing structure of the present invention may further include a rust inhibitor stored in the space in the recess. According to this configuration, the rear end portion of the cable bolt housed in the recess is rust-proof.

  The cable bolt fixing method of the present invention is a cable bolt fixing method for constructing any of the cable bolt fixing structures described above, and the rear end portion of the cable bolt protruding further rearward from the wedge is stored. A rust preventive agent filling step of filling the recessed portion with a rust preventive agent, and a cap attaching step of attaching the cap to the rear end of the socket portion and closing the recessed portion after the rust preventive agent filling step. To do. According to this fixing method, since the concave portion of the socket portion is filled with the rust preventive agent before the cap is attached, the rust prevention treatment of the rear end portion of the cable bolt can be efficiently performed.

  The anchor bolt fixing structure according to the present invention includes a bolt hole drilled in a bolt installation surface, an anchor bolt having a distal end inserted into the bolt hole and protruding rearward from the bolt installation surface, and a bolt embedded in the anchor bolt. A filler filled in the hole, a plate that allows the anchor bolt to be inserted and abuts against the bolt installation surface, a socket portion that is installed behind the plate and through which the anchor bolt is inserted, an inner wall surface of the socket portion, and an anchor bolt A socket inserted from the rear between the socket portion and the socket portion having a recess for accommodating the rear end portion of the anchor bolt protruding rearward from the wedge, and at least a part of the socket portion is fitted inside the recess. In addition, a cap that closes the recess and covers the rear end surface of the anchor bolt is attached to the rear end of the socket portion. The features.

  According to this fixing structure, the rear end portion of the anchor bolt protruding rearward from the wedge is housed in the recess, and the inside of the recess is closed by the cap. Therefore, the rear end portion of the anchor bolt can be closed in the recess by a simple operation such as attaching a cap to the rear end of the socket portion, and an antirust effect can be obtained. In addition, even when the wedge is loosened and separated from the anchor bolt in the process before attaching the cap, the wedge is likely to stay in the recess of the socket portion and the possibility of falling downward is reduced.

  According to the present invention, the cable bolt fixing structure, the cable bolt fixing method, and the anchor bolt fixing which can reduce the possibility of the wedge falling during construction and can easily perform the rust prevention treatment of the anchor bolt. Structure can be provided.

(A) is a front view which shows the cable volt | bolt fixing structure which concerns on 1st Embodiment of this invention, (b) is the sectional drawing. It is a disassembled perspective view which shows the principal part of the cable bolt fixing structure of FIG. It is sectional drawing which shows the fixing method for constructing the cable bolt fixing structure of FIG. (A) is a front view which shows the cable volt | bolt fixing structure which concerns on 2nd Embodiment of this invention, (b) is the sectional drawing. It is a disassembled perspective view which shows the principal part of the cable bolt fixing structure of FIG.

  Hereinafter, embodiments of a cable bolt fixing structure, a cable bolt fixing method, and an anchor bolt fixing structure according to the present invention will be described in detail with reference to the drawings. In the following embodiments, a cable bolt fixing structure using a cable bolt 1 as an example of an anchor bolt will be described.

(First embodiment)
Fig.1 (a) is a front view which shows the cable volt | bolt fixing structure 3 which concerns on 1st Embodiment of this invention, FIG.1 (b) is the sectional drawing. FIG. 2 is an exploded perspective view showing a main part of the cable bolt fixing structure 3. In the following description, when words having concepts such as “front”, “back”, “front end”, and “rear end” are used, the right side in FIG. The left side in) is the rear.

  The cable bolt 1 is applied, for example, to a support for securing the dynamic stability of a rock mass during construction or operation in a rock excavation work such as a tunnel, an underground cavity, a dam, and a slope. Since this type of cable bolt is easier to construct than a lock bolt or PS anchor, which is another supporting member, it is applied to reinforcement by a long bolt in a fragile part such as a fault. Further, since the cable bolt is flexible and can be constructed from a narrow space, it is also applied as a prior support in a large section tunnel. Furthermore, since the cable bolt does not require an introduction force and does not require special construction equipment, for example, it can be applied as a cost reduction measure for a PS anchor in an underground cavity.

  The cable bolt fixing structure 3 includes a bolt hole 103 drilled with a diameter of 60 to 120 mm, for example, in a bolt installation surface 101 on the bedrock 100, a cable bolt 1 inserted into the bolt hole 103, and a cable bolt 1 embedded in the bolt hole. And a filler 5 (for example, cement milk, mortar, etc.) filled and hardened in the bolt hole 103 for fixing to 103. The cable bolt 1 is a stranded wire made of, for example, a strand steel material, and its surface is coated with a coating for preventing corrosion. The front end side of the cable bolt 1 is inserted into the bolt hole 103 with a length of about 15 to 20 m, for example, and the rear end of the cable bolt 1, for example, 100 to 200 mm protrudes rearward from the bolt installation surface 101. .

  The cable bolt fixing structure 3 includes a plate 11 through which the cable bolt 1 is inserted and abutted against the bolt installation surface 101, and a cylindrical socket portion 13 that is installed behind the plate 11 and through which the cable bolt 1 is inserted. ing. The plate 11 has a circular opening 11a through which the cable bolt 1 is inserted. The circular front end surface of the socket portion 13 has a larger diameter than the circular opening portion 11a, and is pressed against the rear surface of the plate 11 at the edge portion of the circular opening portion 11a.

  The socket part 13 has a tapered part 15 formed at the front and a cylindrical part 17 formed at the rear of the tapered part 15. The inner wall surface 15a of the taper portion 15 forms a conical surface formed such that the diameter decreases toward the front. The cylindrical portion 17 has a cylindrical shape having an outer peripheral surface common to the tapered portion 15 and extending further rearward from the rear end of the tapered portion 15. The inner diameter of the cylindrical portion 17 is larger than the maximum inner diameter of the tapered portion 15. A female screw portion 17 s is formed on the inner wall surface 17 a of the cylindrical portion 17.

  Further, the cable bolt fixing structure 3 has a wedge 19 that is inserted into a gap between the inner wall surface 15a of the tapered portion 15 and the cable bolt 1 and functions as a wedge. The wedge 19 has a conical surface corresponding to the tapered portion 15 and is composed of two wedge members 19a and 19b facing each other with the cable bolt 1 interposed therebetween. The rear end of the wedge 19 protrudes rearward from the rear end of the tapered portion 15. A rear end portion 1 a of the cable bolt 1 protrudes further rearward from the wedge 19, and the rear end portion 1 a is accommodated in a recess 21 configured as a hollow portion of the cylindrical portion 17.

  Unlike the PS anchor, the cable bolt 1 is not tensioned at the time of installation. Therefore, the cable bolt 1 has no tensile force immediately after the construction of the cable bolt fixing structure 3. The tensile force of the cable bolt 1 is not generated until the displacement associated with the rock 100 is loosened. When a tensile force is generated in the cable bolt 1, the wedge 19 firmly holds the cable bolt 1 so as to bite into the surface of the cable bolt 1 due to the wedge effect. In the fixing structure 3 in this embodiment, the tensile force of the cable bolt 1 is not generated immediately after the construction. In the present cable bolt 1 that generates a tensile force due to a displacement caused by loosening of the bedrock or the like, an operation of introducing a tension force into the cable bolt 1 by fitting a bolt or the like to the end of the cable immediately after construction is not performed.

  Further, the cable bolt fixing structure 3 has an internal screw type cap 23 attached to the rear end of the socket portion 13. On the outer peripheral surface 23a on the distal end side of the cap 23, a male screw portion 23s that is screwed into the female screw portion 17s is formed. With this configuration, the cap 23 closes the inside of the recess 21 and covers the rear end face 1 b of the cable bolt 1 by fitting the front end side of the cap 23 into the recess 21 and screwing in. A tool hole 23t for inserting a tool for rotating the cap 23 is provided on the side surface of the head portion of the cap 23. Further, a bottomed cylindrical hole 23b into which the rear end portion 1a of the cable bolt 1 is inserted from the front is formed on the front end surface of the cap 23.

  Since the rear end surface 1b of the cable bolt 1 is a cut surface cut out from the cable material, there is no coating for preventing corrosion and the metal is exposed, but the rear end surface 1b is in a space closed by the cap 23. By being, generation | occurrence | production of corrosion and rust is suppressed. Further, the recess 21 closed by the cap 23 is filled with a rust inhibitor 27 such as grease. Due to the presence of the rust preventive agent 27, the rear end portion 1 a is immersed in the rust preventive agent 27 in the recess 21, so that the rust preventive effect of the rear end surface 1 b of the cable bolt 1 is further increased. In order to improve the closing property of the recess 21, an O-ring is provided around the front end side of the cap 23, and the O-ring is sandwiched between the front end surface of the head portion of the cap 23 and the rear end surface of the socket portion 13. You may be made to do.

  Further, the cable bolt fixing structure 3 has an inner sleeve 29 that is sandwiched between the cap 23 and the wedge 19 in the recess 21 and through which the rear end portion 1 a of the cable bolt 1 is inserted. The inner sleeve 29 has a cylindrical body part 29c, a flange 29a projecting radially from the body part 29c at the front end, and a flange 29b projecting radially from the body part 29c at the rear end. The flange 29 a contacts the rear end surface 19 s of the wedge 19, and the flange 29 b contacts the front end surface of the cap 23. The flange 29a has a larger diameter than the flange 29b. When the cap 23 is screwed into the socket portion 13 and moves forward, the inner sleeve 29 is pushed forward by the front end surface of the socket portion 13, and the wedge 19 is pushed forward via the inner sleeve 29. Then, the wedge 19 is firmly bitten between the cable bolt 1 and the socket portion 13 by pressing from the cap 23, so that the looseness of the wedge 19 is suppressed.

  At this time, because of the presence of the flange 29a of the inner sleeve 29, the rear end surfaces 19s of the two wedge members 19a and 19b are pushed uniformly and are likely to be flush with each other. The gripping function of the cable bolt 1 is demonstrated correctly. Moreover, since the trunk | drum 29c behind the flange 29a is smaller diameter than the flange 29a, the clearance gap between the said trunk | drum 29c and the inner wall surface 17a of the cylindrical part 17 can be enlarged. Therefore, during construction, for example, the operator's hand can easily enter through this gap, and the operator can check the state of the rear end of the wedge 19 by hand.

  The fixing method for constructing the cable bolt fixing structure 3 will be described with reference to FIG. The fixing method of the present embodiment includes a wedge structure assembling step, a rust preventive agent filling step, and a cap attaching step.

  As shown in FIG. 3, the cable bolt 1 is inserted into the drilled bolt hole 103 and fixed with the filler 5. Thereafter, the plate 11 and the socket portion 13 are inserted into the rear end of the cable bolt 1 and set on the bolt installation surface 101, and the wedge 19 is inserted into the gap between the inner wall surface 15 a of the taper portion 15 of the socket portion 13 and the cable bolt 1. Is inserted (wedge structure assembly process). Thereafter, the inner sleeve 29 is set behind the wedge 19 and the recess 21 is filled with a rust inhibitor 27 so as to fill the recess 21 (rust preventive agent filling step). Thereafter, the cap 23 is screwed into the rear end of the socket portion 13 by using a tool to close the concave portion 21 (cap attaching step). At this time, as the cap 23 advances, excess rust inhibitor 27 overflows from the recess 21 to the outside, and the space of the recess 21 is satisfactorily filled with the rust inhibitor 27. Further, as the cap 23 advances, the wedge 19 is pressed forward via the inner sleeve 29, and the wedge 19 firmly bites between the cable bolt 1 and the socket portion 13.

  Then, the effect by the cable bolt fixing structure 3 and fixing method mentioned above is demonstrated. According to the cable bolt fixing structure 3, the rear end 1 a of the cable bolt 1 protruding rearward from the wedge 19 is housed in the recess 21, and the inside of the recess 21 is closed by the cap 23. Therefore, the rear end portion 1a of the cable bolt 1 can be closed in the recess by a simple operation such as attaching the cap 23 to the rear end of the socket portion 13, and an antirust effect can be obtained. Moreover, since the socket part 13 has the cylindrical part 17 extended to the back rather than the wedge 19, when the wedge 19 loosens and separates from the cable bolt 1 between the above wedge structure assembling process and the cap attaching process. In addition, the wedge 19 is easily retained by being caught in the concave portion 21 of the socket portion 13, and the possibility that the wedge 19 falls downward is reduced.

  Further, according to the fixing method described above, when the cap 23 is attached, the wedge 19 is pressed forward via the inner sleeve 29, and the wedge 19 bites firmly between the cable bolt 1 and the socket portion 13. The loosening of the wedge 19 is suppressed. Further, before attaching the cap 23, the concave portion 21 of the socket portion 13 is filled with a rust preventive agent 27, and the cap 23 is screwed while overflowing the rust preventive agent 27. Rust prevention treatment can be performed more efficiently. In the fixing structure 3 of the present embodiment, a tensile force is generated in the cable bolt 1 due to the displacement accompanying the loosening of the bedrock. Therefore, an operation of introducing a tension force to the cable bolt 1 is not performed at the time of construction. Accordingly, it is not necessary to fit a bolt for applying a tensile force to the rear end portion 1a of the cable bolt 1, and the cable bolt 1 is cut and the rear end portion 1a is placed in the recess 21 of the socket portion 13. There is no problem even if it is housed.

(Second Embodiment)
FIG. 4A is a front view showing a cable bolt fixing structure 53 according to the second embodiment of the present invention, and FIG. 4B is a sectional view thereof. FIG. 5 is an exploded perspective view showing the main part of the cable bolt fixing structure 53. In the cable bolt fixing structure 53 according to the present embodiment, the same or equivalent components as those in the cable bolt fixing structure 3 of the first embodiment are denoted by the same reference numerals in the drawings, and redundant description is omitted. .

  The cable bolt fixing structure 53 includes a cap 73 instead of the cap 23 in the cable bolt fixing structure 3. Since the head portion 73h of the cap 73 has a hexagonal bolt shape, the cap attaching step can be executed using a general-purpose tool such as a hexagon wrench. The cable bolt fixing structure 53 includes a ring-shaped inner sleeve 79 instead of the inner sleeve 29 in the cable bolt fixing structure 3. The inner sleeve 79 does not include the flanges 29 a and 29 b included in the inner sleeve 29, but can achieve a function of transmitting the pressing force from the cap 73 to the wedge 19.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to the said embodiment, You may change in the range which does not change the summary described in each claim. For example, in the embodiment, the structure in which the caps 23 and 73 press the wedge 19 via the inner sleeves 29 and 79 has been described. However, the inner sleeves 29 and 79 are not essential, and the front end surfaces of the caps 23 and 73 are the wedge 19. The rear end face 19s may be pressed directly. Further, in the embodiment, a configuration in which only a part (tip side) of the caps 23 and 73 is fitted into the recess 21 is described as an example, but instead, a cap that is fitted into the recess 21 is used instead. It may be used. Moreover, you may employ | adopt combining suitably the component with which the cable bolt fixing structure 3 of 1st Embodiment is equipped, and the component with which the cable bolt fixing structure 53 of 2nd Embodiment is equipped.

  In addition, the fixing structure 3 and the fixing method according to the cable bolt 1 have been described as the embodiment of the present invention. However, the cable bolt in the fixing structure and the fixing method of the present invention is inserted into the bolt hole of the bedrock and fixed by the filler. It is needless to say that the cable bolt of the fixing structure and the fixing method of the present invention can be replaced by any one that generates a tensile force due to the displacement caused by the loosening of the rock after being applied and has a similar function. That is, the fixing structure of the present invention is not limited to the fixing structure of the cable bolt but can be applied to the fixing structure of all anchor bolts including the cable bolt.

  DESCRIPTION OF SYMBOLS 1 ... Cable bolt (anchor bolt), 1a ... Rear end part, 1b ... Rear end surface, 3,53 ... Cable bolt fixing structure, 5 ... Filler, 11 ... Plate, 13 ... Socket part, 15a ... Inner wall surface, 17a ... Inner wall surface, 17s ... female screw part, 19 ... wedge, 19s ... rear end surface, 21 ... concave part, 23 ... cap, 23s ... male screw part, 27 ... rust preventive agent, 29, 79 ... inner sleeve, 29a ... flange, 101 ... bolt installation surface, 103 ... bolt hole.

Claims (5)

A bolt hole drilled in the bolt installation surface;
A cable bolt having a tip side inserted into the bolt hole and projecting backward from the bolt installation surface,
A filler filled in the bolt hole to embed the cable bolt;
A plate for inserting the cable bolt and abutting against the bolt installation surface;
A socket part installed behind the plate and through which the cable bolt is inserted;
A wedge inserted from the rear between the inner wall surface of the socket part and the cable bolt,
The socket portion has a recess for storing a rear end portion of the cable bolt protruding backward from the wedge,
A male screw portion that is screwed into a female screw portion formed on the inner wall surface of the concave portion is formed at the front portion, the front portion is screwed inside the concave portion, and the inside of the concave portion is closed to close the cable bolt. A cap having a monolithic structure covering the rear end surface is attached to the rear end of the socket part ,
An inner sleeve is provided between the front end face of the cap and the wedge in the recess, and the rear end of the cable bolt is inserted through the inner sleeve.
By the advance of the cap screwed into the recess, the front end surface of the front portion presses the wedge forward through the inner sleeve ,
A fixing structure for a cable bolt, wherein a hole portion into which a rear end portion of the cable bolt protruding rearward of the inner sleeve is inserted is formed in the front end surface . The cable bolt fixing structure according to claim 1 , wherein the inner sleeve has a flange provided at a front end and abutting against a rear end surface of the wedge. Fixing structure of the cable bolt of claim 1 or 2, characterized by further comprising a been antirust agent accommodated in the space of the recess. A cable bolt fixing method for constructing the cable bolt fixing structure according to any one of claims 1 to 3 ,
Rust preventive agent filling step of filling the concave portion in which the rear end of the cable bolt protruding further rearward from the wedge is housed,
A cable bolt fixing method comprising: a cap attaching step of attaching the cap to a rear end of the socket portion and closing the concave portion after the rust preventive agent filling step. A bolt hole drilled in the bolt installation surface;
An anchor bolt having a tip side inserted into the bolt hole and protruding rearward from the bolt installation surface;
A filler filled in the bolt hole so as to embed the anchor bolt;
A plate through which the anchor bolt is inserted and in contact with the bolt installation surface;
A socket part installed behind the plate and through which the anchor bolt is inserted;
A wedge inserted from behind between the inner wall surface of the socket part and the anchor bolt,
The socket portion has a recess for storing a rear end portion of the anchor bolt protruding backward from the wedge,
A male screw portion that is screwed into a female screw portion formed on the inner wall surface of the concave portion is formed at the front portion, the front portion is screwed inside the concave portion, and the inside of the concave portion is closed to close the anchor bolt. A cap having a monolithic structure covering the rear end surface is attached to the rear end of the socket part ,
An inner sleeve is provided between the front end surface of the cap and the wedge in the recess, and the rear end portion of the anchor bolt is inserted through the inner sleeve.
By the advance of the cap screwed into the recess, the front end surface of the front portion presses the wedge forward through the inner sleeve ,
The anchor bolt fixing structure , wherein a hole portion into which a rear end portion of the anchor bolt protruding rearward of the inner sleeve is inserted is formed in the front end surface .

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