JP2017210809A - Jig and method for forced unloading from anchor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forced unloading jig for an anchor that enhances work safety when lifting a load from an anchor cable.SOLUTION: A forced unloading jig for an anchor comprises an unloading wedge fitted on a tip part of an anchor head 7, a cylindrical coupler case 2 for enclosing the unloading wedge, jack means for applying tension to the coupler case, and a release pipe 6 fitted on a hole 7a of the anchor head after the fastening wedge has been removed from the hole. The release pipe 6 has an end 6a inserted and fastened to the anchor head hole, and a body part 6b fitted to surround an outer peripheral surface of an anchor cable 4 between the anchor head and the coupler case. A protrusion 6c on the other end of the release pipe penetrates inside from an outside of a hole of the coupler case and comes in contact with an edge surface 3a of the unloading wedge separated appropriately from an edge surface 2b of the coupler case, thus lifting tensile force from the anchor cable.SELECTED DRAWING: Figure 3

Description

  The present invention relates to, for example, an existing cable replacement / repair related to a cable used for an oblique cable of a cable-stayed bridge, a retaining wall, a retaining wall, or a slope (hereinafter referred to as an anchor cable). The present invention relates to a jig used for forcibly unloading the tensile force of an anchor, and an anchor unloading method using the jig.

  For example, the diagonal cable of the cable-stayed bridge is installed obliquely from the main tower to the abutment in order to suspend the bridge girder, and the anchor head having a conical hole is attached to the anchor head of the cable. A plurality of wedges formed conically in the hole are disposed in a state of being set on the outer peripheral surface of the diagonal cable. Then, the wedge driven in from the outside to the inside grips the diagonal cable by the inner teeth engraved in the circumferential direction of the inner wall surface of the wedge biting into the outer peripheral surface of the diagonal cable. Further, due to the tensile force of the diagonal cable, the wedge is restrained by the conical peripheral wall of the hole and the wedge bites into the outer peripheral surface of the diagonal cable more, so that the end of the diagonal cable is brought into contact with the anchor head. It is supposed to be retained.

  When repairing or replacing the diagonal cable, the tensile force of the diagonal cable must be unloaded from the state in which the diagonal cable is tensioned and fixed. For this purpose, the diagonal cable must be pulled by the jack means at the fixing portion, and then pulled out from the end face of the anchor head, and the wedges biting into the diagonal cable must be taken out from the hole of the anchor head.

  Therefore, conventionally, as described in Patent Document 1, as the above-described solution, the tip end portion of an anchor cable (corresponding to a diagonal cable) is held by unloading wedges, and the unloading wedges are held by jacks. The fixing wedge is separated from the anchor head by applying a tensile force to the anchor cable via the anchor cable and removed from the anchor cable. Thereafter, a flat shutter is inserted between the unloading wedge and the anchor head, and then the tensile force (tensile force) applied to the anchor cable by the jack is unloaded.

  The tip of the unloading wedge is brought into contact with one side of the shutter so that the unloading wedge is in contact with the shutter in the same direction as the anchor cable moves due to unloading. It is prevented from moving. When the outer coupler holding the unloading wedge is forcibly moved to the fixing side, the unloading wedge is relatively moved to the opposite side, and the wedge effect of the unloading wedge is deactivated. . Thus, it is known that the tensile force (tensile force) of the anchor cable is unloaded.

JP 2003-268766 A

  However, in the conventional cable unloading method, since the wedge is forcibly released by the shutter plate member having the U-shaped notch, attention must be paid to the contact state with respect to the end surface of the unloading wedge. Visual monitoring cannot be neglected, and it is necessary to pay attention to work safety. The anchor unloading jig and the unloading method according to the present invention have been proposed to solve such a problem.

  The gist of the present invention for solving the above-mentioned problems of the anchor unloading jig according to the present invention is to fix the anchor head by means of a fixing wedge disposed on the anchor head of the anchor portion of the anchor cable. A jig for unloading the tensile force of the anchor cable held by projecting the distal end portion of the cable from an end surface, wherein the outer peripheral portion is a tapered surface attached to the distal end portion of the anchor head. An unloading wedge for unloading, and a conical-shaped hole that penetrates the taper surface of the unloading wedge in an axial direction so that the end surface of the unloading wedge extends from the end surface on one end side of the case A reaction force is applied to the tubular coupler case containing the unloading wedge and appropriately spaced from the end surface on one end side of the case so as not to protrude, and the anchoring portion for the anchor cable. After the anchoring cable is pulled through the anchor wedge, the fixing wedge is separated from the anchor head hole, so that the coupler case is pulled, and the fixing wedge is removed from the anchor head hole. One end portion is inserted into the hole, and a main body portion is attached so as to surround an outer peripheral surface of the anchor cable between the anchor head and the coupler case, and a protruding portion at the other end portion is connected to the coupler case. A hole that enters the hole from the outside to the inside and abuts against the end surface of the unloading wedge that is appropriately spaced from the end surface of the case, and unloads the tensile force of the anchor cable. It is comprised from the release pipe divided | segmented along an axis line.

  The other end portion of the coupler case is provided with a connecting means for connecting to an end portion of a jack tension transmitting member and one end portion of a joint member screwed at the other end portion.

  The coupler case internal space between the unloading wedge and one end of the joint member is provided with a biasing means for biasing the unloading wedge toward the anchor head.

  The ram chair, which is a reaction force member in the jack means, is a cylindrical body, and a side wall of the ram chair surrounds the outer peripheral surface of the anchor cable and allows a window to be inserted into the hole of the anchor head. It is provided.

  On the inner wall surface of the ram chair, there is provided a lifting prevention means for preventing the anchor head from floating from the fixing portion due to the tensile force of the jack means.

  Attachment means for detachably attaching a handle member for safety work is provided on each outer peripheral portion of the release pipe divided body.

  The gist for solving the above-mentioned problems of the anchor unloading method according to the present invention to achieve the object is to form a forcible unloading jig for an anchor according to the present invention, and to release the release pipe into the hole of the anchor head. After the insertion, the protrusion at the other end of the release pipe prevents the unloading wedge from moving toward the anchor head, and the unloading wedge and the coupler case where the tensile force is released are relative to each other. By releasing the tension restraint state of the unloading wedge by movement, the tensile force of the anchor cable is unloaded.

  The end portion of the ram chair is provided with a supporting pressure plate for ensuring the supporting pressure by the jack of the jack means, and the pulling operation by the jack is performed.

  While the anchor head is prevented from being lifted from the fixing portion by the pulling force of the jack means by the lifting prevention means provided on the inner wall surface of the ram chair, the anchor cable is pulled by the jack means to lift the fixing wedge. Including the removal.

  According to the forced unloading jig of the anchor and the forced unloading method of the present invention, the protruding portion on the other end side of the release pipe in which the unloading wedge contained in the coupler case is attached to the anchor head side By releasing the pulling force of the coupler case pulled by the jack means, the tightening and gripping action of the unloading wedge is released, and the anchor cable is unloaded.

  Further, when the fixing wedge is taken out and removed, the anchor head is prevented from being lifted from the fixing portion, and the safety of the unloading operation is ensured.

  Furthermore, by providing an urging means in the internal space of the coupler case, the unloading wedge is urged toward the anchor head to bite into the anchor cable, and the anchor cable can be reliably pulled by the jack means. it can.

  Each of the release pipe split bodies is provided with attachment means for a handle member. Therefore, when the release pipe is inserted into the hole of the anchor head and attached to the outer peripheral portion of the anchor cable, the attachment work is performed. This has the excellent effect of ensuring safety.

It is explanatory drawing (A)-(C) along the operation | movement procedure of the unloading method which concerns on this invention. It is explanatory drawing (A)-(C) along the operation | movement procedure of the unloading method which concerns on the same this invention. It is explanatory drawing (A)-(C) along the operation | movement procedure of the unloading method which concerns on the same this invention. It is a use state side view which fractures | ruptures and shows a part of apparatus in the use condition of the unloading apparatus 1 which concerns on the same invention. As for the unloading apparatus 1 according to the present invention, a perspective view (A) of a state in which the coupler case 2 and the tension transmission member 8b are mounted on the anchor head 7, the unloading wedge 3 and the press which are sequentially installed in the coupler case 2 It is a side view (B) of the member 11, the biasing means 12, and the joint member 10, respectively. 2 is a perspective view of the unloading apparatus 1 according to the present invention in a state in which a ram chair 14 is covered with a hanker head 7. FIG. FIG. 3 is a perspective view of the unloading apparatus 1 according to the present invention in a state in which the release pipe 6 is inserted into the anchor head 7 by the handle member 15 after the fixing wedge 5 is removed. They are the side view (A) and the top view (B) of the unloading wedge 3 in the unloading apparatus 1 according to the present invention. Sectional view (A) of coupler case 2 assembly, sectional view of coupler case 2 (B), sectional view of pressing member 11 (C), sectional view of joint member 10 of unloading apparatus 1 according to the present invention (D). It is the top view (A) and longitudinal cross-sectional view (B) of the bearing plate 13 of the unloading apparatus 1 which concerns on the same invention. They are the longitudinal cross-sectional view (A) of the ram chair 14 which is a reaction force member of the unloading apparatus 1 which concerns on the same invention, a front view (B), and a rear view (C). It is the front view (A) and longitudinal cross-sectional view (B) of the lifting prevention means 14b provided in the ram chair 14 of the unloading apparatus 1 which concerns on the same invention. They are the side view (A) and front view (B) which fractured | ruptured a part of release pipe 6 of the unloading apparatus 1 which concerns on the same invention.

  The anchor unloading jig 1 according to the present invention and the forcible unloading method for constructing the anchor using the forcible unloading jig 1 are as shown in FIGS. In addition, the anchor case 4 and the unloading wedge 3 are pulled and tensioned by the coupler case 2 and the unloading wedge 3, and the fixing wedge 5 is pulled out and removed, and then the unloading wedge 3 is gripped by the release pipe 6. Is released, and the tensile force (tensile force) of the anchor cable 4 is reliably unloaded.

  The anchor unloading jig 1 will be described with reference to the drawings. As shown in FIG. 1 (A), an anchor cable 4 made of a PC steel wire used for a cable-stayed bridge, a slope, a retaining wall or the like is perforated in the anchor head 4 at a fixing portion at both ends of the cable. It is held by the wedge effect by the fixing wedge 5 inserted in the conical hole 7a.

  An end 4a of the anchor cable 4 is projected from the end face of the anchor head 7 by a dimension a (for example, 80 mm). The fixing wedge 5 is a set of three divided bodies each having a biting tooth (not shown) on the inner peripheral surface.

As shown in FIG. 4, the schematic configuration of the anchor unloading jig 1 for pulling the end 4a of the anchor cable 4 in the pulling direction is as follows.
Unloading (pulling) wedge 3 having a tapered surface on the outer peripheral portion thereof and internal teeth 3b for biting on the inner peripheral surface thereof, which is a divided body attached to the distal end portion of the anchor head 7.
1C, FIG. 4 and FIG. 4 having a conical shape and a hole 2a (see FIGS. 1B and 1C) that engage with the tapered surface of the unloading wedge 3 in the axial direction. As shown in FIG. 7 (A), the unloading wedge 3 is contained by being appropriately separated from the end surface 2b of the case one side so that the end surface 3a of the unloading wedge 3 does not protrude from the end surface 2b of the case. A cylindrical coupler case 2 to be
In order to separate the fixing wedge 5 from the hole 7a of the anchor head 7 by applying a reaction force to the fixing portion 7b for the anchor cable and pulling the anchor cable 4 through the unloading wedge 3, Jack means 8 for pulling the coupler case 2;
After the fixing wedge 5 is removed from the hole 7a of the anchor head 7, one end 6a is inserted into the hole 7a (see FIG. 3A), and the anchor head 7 and the coupler case 2 are inserted. The main body 6b is mounted so as to surround the outer peripheral surface 4b (see FIG. 2C) of the anchor cable 4 between and the protruding portion 6c at the other end to the hole 2a of the coupler case 2 from the outside to the inside. To the end surface 3a of the unloading wedge 3 that is appropriately separated from the case end surface 2b and unloads the tensile force of the anchor cable 4, and the cylindrical body is moved in the longitudinal direction. The release pipe 6 is divided along the axis.

  Each component will be described in turn. The unloading wedge 3 is another metal wedge member different from the fixing wedge 5 of the anchor head 7 in the fixing portion 7b shown in FIG. 4, and is shown in FIGS. 6 (A) and 6 (B). Thus, it has a taper-shaped outer peripheral surface which is divided into three in the circumferential direction and has a conical shape as a whole, and has inner teeth for cable biting on the inner peripheral surface. Although the fixing wedge 5 is different in size and the like, the basic structure and operation are the same.

  As shown in FIGS. 7A and 7B, the coupler case 2 is for pulling the end portion 4a of the anchor cable 4 and is a metal cylinder elongated in the axial direction. As shown in FIGS. 4, 7A and 7D, the other end portion 2c of the coupler case 2 includes an end portion 8c of the tension transmitting member 8b of the jack 8a and the other end portion 10a. A connecting means (for example, a screw portion) 2d for connecting with one end portion 10b of the joint member 10 to be screwed is provided on the inner peripheral portion.

  Further, as shown in FIGS. 7A and 7C, a pressing member 11 for pushing the unloading wedge 3 included in the coupler case 2 toward the anchor head 7 is provided. The through hole 11 a of the pressing member 11 is provided for inserting the end 4 a of the anchor cable 4.

  In the internal space of the coupler case 2, the unloading wedge 3 is urged toward the anchor head 7 between the enclosed unloading wedge 3 and the one end 10 b of the joint member 10. A biasing means (one example, a coil spring) 12 is provided.

  As shown in FIG. 4, the jack means 8 concentrates the load on a center hole type jack 8a, a PC steel rod 8b as a tension transmission member, a nut 8d as a fixing member for the PC steel rod 8b, and the like. The pressure bearing plate 13 as an auxiliary member for securing the pressure bearing of the jack 8a and the cylindrical ram chair 14 as a reaction force member for taking a reaction force on the fixing portion 7b. Each component of the jack means 8 will be described.

  As shown in FIG. 8, the pressure bearing plate 13 is a metal disk-like body having a required thickness, and a through hole 13 a is provided in the central portion so that the tension transmitting member 8 b is inserted. Further, as shown in FIG. 9, the ram chair 14 is a metal cylindrical body as a whole, and a release pipe 6 is surrounded on the side wall of the anchor cable 4 so as to surround the hole 7 a of the anchor head 7. A window 14a is provided to enable the work to be inserted into the window 14a. Further, a jack hole 14g and a fixing hole 14h are respectively provided in the flange portions at both ends of the cylindrical body in the ram chair 14 with appropriate hole diameters.

  Further, on the inner wall surface of the ram chair 14, as shown in FIG. 4, a lifting prevention means 14 b for preventing the anchor head 7 from floating from the fixing portion 7 b due to the tensile force of the jack means 8 is provided in a cylindrical body. It is attached along the axial direction which is the longitudinal direction of the.

  As shown in FIGS. 9 and 10, the shape and the like of the lifting prevention means 14 b is a long and thin metal rectangular bar member. The mounting screw 14f (see FIG. 4) is inserted into a through hole 14e provided in the side wall of the cylinder 14d of the ram chair 14, and the tip of the screw is screwed into the screw hole 14c to prevent the lifting. The means 14b is attached and fixed to the inner wall surface of the cylindrical body 14d. Accordingly, as shown in FIGS. 5B and 5C, the end face of the anchor head 7 is suppressed at the end face on the one end side in the longitudinal direction of the lift preventing means 14b to prevent the anchor head 7 from lifting. It is.

  Next, the joint member 10 is a member for transmitting the tensile force of the jack means 8 to the coupler case 2, and as shown in FIG. 7D, the whole is a metal cylinder. A male screw portion is provided on the outer peripheral surface on the one end portion 10b side, and a female screw portion 10c is provided on the inner peripheral wall surface of the recess on the other end portion 10a side. As shown in FIG. 7A, the male screw portion on the one end portion 10 b side is screwed into the connecting means 2 d of the coupler case 2. Further, the end portion 8c of the tension transmitting member 8b is screwed into the female screw portion 10c.

  Further, as shown in FIGS. 11A and 11B, the release pipe 6 is a divided body obtained by dividing the cylindrical body into two parts in the circumferential direction, and the center portion combining the divided bodies is connected to the anchor cable 4. Is to be inserted.

  A screw part 6e, which is an attaching means for detachably attaching the handle member 15 to the outer peripheral part of the main body part 6b (see FIG. 5-C), is provided at the middle part of the release pipe 6 in the longitudinal direction. When the release pipe 6 is mounted in the hole 7a of the anchor head 7, the handle member 15 is gripped and the release pipe 6 is operated so that an operator can work away from the anchor head 7 so that work safety is achieved. It is for aiming at.

  After forming the anchor unloading jig 1 according to the present invention described above, a method for forcibly unloading the anchor constructed using the anchor unloading jig 1 will be described with reference to the drawings. To do. First, as shown in FIGS. 1A and 1B, the coupler case 2 is inserted into the end 4a of the anchor cable 4 projecting from the end face of the anchor head 7 with a dimension a (about 80 mm). Insert it from 2a. The end face on one end side of the coupler case 2 abuts on the end face of the fixing wedge 5.

  Next, as shown in FIG. 1 (C), the unloading wedge 3 shown in FIG. 6 is inserted from the other end side of the coupler case 2 and driven in the direction toward the anchor head 7 with a tool. The unloading wedge 3 is attached to the end 4 a of the anchor cable 4.

  As shown in FIG. 1C, the end surface 3 a of the unloading wedge 3 is at a position appropriately separated from the end surface 2 b on one end side of the coupler case 2.

  Thereafter, the pressing member 11 is placed on the unloading wedge 3 with respect to the coupler case 2 as shown in FIGS. 12, the joint member 10 is screwed into the connecting means 2d of the coupler case 2 to close the opening. Thereby, the urging force of the urging member 12 acts to push the unloading wedge 3 into the anchor head 7 via the pressing member 11.

  And as shown to FIG. 5-A (A), the edge part 8c of the tension | tensile_strength transmission member 8b is screwed together and connected with the thread part 10c of the said joint member 10. FIG.

  After that, as shown in FIG. 5B, the tension transmission member 8b, the coupler case 2, and the anchor head 7 are attached to the tension transmission member 8b from the fixing hole 14h side on one end side of the ram chair 14 which is a reaction force member. The flange portion at one end is brought into contact with the base 9 and the ram chair 14 is placed.

  The position of the ram chair 14 is adjusted so that the lifting prevention means 14b is on the center line of the anchor head 7, and the ram chair 14 is disposed. The lifting prevention means 14b may be previously attached to the inner wall surface of the ram chair 14, or after the ram chair 14 is placed on the base 9, the lifting prevention means 14b is inserted through the window 14a. Then, it may be attached and fixed with the attachment screw 14f.

  Thereafter, as shown in FIG. 4, a pressure bearing plate 13 is disposed on the ram chair 14, and a jack (for example, a center hole jack) 8a is further disposed, and the tension transmitting member 8b is fixed by a nut 8d. In addition, a supply / discharge hose (not shown) of the high-pressure oil supply device is connected to the high-pressure oil connection portions 8e and 8f, respectively.

  As shown in FIG. 4, after the jack means 8 is disposed on one end side of the ram chair 14, as shown in FIGS. 2 (A) and 4, the high-pressure oil supply device connects the high-pressure connection portions 8e and 8f. The jack means 8 is actuated via, the reaction force is applied to the fixing portion 7b, and the coupler case 2 is pulled straight by the bearing plate 13. After the coupler case 2 moves in the pulling direction and a slight gap b is generated, the unloading wedge 3 firmly holds the end 4a of the anchor cable 4 and pulls it up.

  As shown in FIG. 2B, when the coupler case 2 moves by dimension C (about 45 mm), the fixing wedge 5 is pulled out from the hole 7a of the anchor head 7, so that the fixing wedge 5 is removed from the ram chair 14. Is removed from the window 14a using a tool or the like. Thus, the state shown in FIG.

  In addition, when unloading the last one of the plurality of anchor cables 4, the anchor head 7 is also pulled together with the fixing wedge 5 and tends to float from the fixing portion 7b. As shown in FIGS. 4 and 5-B, the anchor head 7 is prevented from being lifted by restraining the end face of the anchor head 7 with the end face of the lift preventing means 14b of the ram chair 14.

  Next, as shown in FIG. 3A, a pair of one end portions 6a of the release pipe 6 of the two-divided body are attached to the hole 7a of the anchor head 7 related to the removed fixing wedge 5. For this purpose, as shown in FIG. 5C, the handle member 15 is attached to the main body portion 6b of the release pipe 6 by screwing the end portion thereof to the attaching means 6e. The operator holds the handle member 15 and inserts the two-part release pipe 6 from the window 14a of the ram chair 14, and inserts the respective end portions 6a into the holes 7a of the anchor head 7, The release pipes 6 and 6 are put on the outer peripheral surface 4b of the anchor head 4 between the head 7 and the coupler case 2 so as to face each other.

  Next, as shown in FIG. 3 (B), the jack unit 8 gradually relaxes the tensile force of the coupler case 2. As a result, the coupler case 2 returns to the anchor head 7 side, and the protrusion 6c of the release pipe 6 enters the hole 2a of the coupler case 2 from the outside to the inside.

  Further, when the coupler case 2 whose tensile force is weakened moves to the anchor head 7 side, the end surface 6d of the projecting portion 6c of the release pipe 6 is separated from the end surface 2b without protruding from the end surface 2b. It contacts the end surface 3a.

  Next, as shown in FIG. 3 (C), when the tension on the coupler case 2 is further unloaded by the jack means 8, the coupler case 2 moves to the anchor head 7 side. This is because the unloading wedge 3 cannot move due to contact with the end surface 6d of the projecting portion 6c of the release pipe 6, but the restraining force of the coupler case 2 against the unloading wedge 3 is weakened. The component force acts on the tapered surface of the hole 2a of the coupler case 2 by the reaction force of the unloading wedge 3 held by the restraining force, and the coupler case 2 is forcibly moved to the anchor head 7 side.

  In this way, the clamping force applied to the unloading wedge 3 by the hole 2a of the coupler case 2 is released, and as a result, the relative movement d between the unloading wedge 3 and the coupler case 2 (FIG. 3B, (Comparison with (C)), the gripping force (clamping force) of the unloading wedge 3 against the anchor cable 4 is relaxed, and the tensile force of the anchor cable 4 is unloaded.

  As described above, in the anchor unloading method, the unloading operation of the anchor cable 4 by the forced unloading jig 1 is repeatedly performed. The above-described embodiment is merely an embodiment, and is not particularly limited by this embodiment. The embodiment includes a part of alternative means such as other well-known techniques and well-known techniques, and the contents of the claims. Should not be interpreted narrowly.

  According to the forced unloading jig for anchors and the forced unloading method according to the present invention, the present invention can be widely applied to unloading cables to which a tensile force (tensile force) is applied.

1 Anchor unloading jig,
2 Coupler case, 2a hole,
2b end face, 2c other end,
2d connecting means (screw part),
3 Wedge for unloading, 3a end face,
3b internal teeth,
4 anchor cable, 4a end,
4b outer peripheral surface,
5 fixing wedge,
6 release pipe, 6a one end,
6b body part, 6c protrusion part,
6d end face, 6e attachment means (screw part),
6f through hole,
7 anchor head, 7a hole,
7b fixing section,
8 Jacking means,
8a jack (example: center hole jack)
8b Tension transmission member (PC steel bar),
8c end, 8d nut,
8e, 8f High pressure oil connection part,
9 base,
10 joint member, 10a other end,
10b one end, 10c screw part,
11 pressing member, 11a through-hole,
12 Biasing means (coil spring),
13 bearing plate,
14 reaction force member (ram chair), 14a window,
14b Lifting prevention means (disk holder),
14c screw hole,
14d cylinder, 14e through-hole,
14f mounting screw, 14g jack hole,
14h fixing hole, 14j mounting hole,
15 Handle member.

Claims (9)

A jig for unloading the tensile force of the anchor cable held by the tip of the cable protruding from the end face of the anchor head by a fixing wedge disposed on the anchor head of the anchor portion of the anchor cable Because
Unloading wedge for unloading having a tapered surface on the outer peripheral portion thereof in a divided body attached to the tip of the anchor head;
It has a hole that penetrates in the axial direction in a conical shape that engages with the tapered surface of the unloading wedge so that the end surface of the unloading wedge does not protrude from the end surface of the case end as appropriate. A cylindrical coupler case that is spaced apart and encloses the unloading wedge;
Jack means for pulling the coupler case in order to separate the anchoring wedge from the hole of the anchor head by taking a reaction force on the anchor cable fixing portion and pulling the anchor cable through the unloading wedge;
After the fixing wedge is removed from the hole of the anchor head, one end portion is inserted into the hole and the main body portion surrounds the outer peripheral surface of the anchor cable between the anchor head and the coupler case. And the protruding portion of the other end enters the hole of the coupler case from the outside to the inside and contacts the end surface of the unloading wedge that is appropriately separated from the end surface of the case, and the tensile force of the anchor cable A release pipe formed by dividing the cylindrical body along the longitudinal axis,
Anchor unloading jig characterized by. The other end portion of the coupler case is provided with a connecting means for connecting with one end portion of the joint member screwed at the end portion and the other end portion of the tension transmission member of the jack,
The anchor unloading jig according to claim 1, wherein: The coupler case internal space between the unloading wedge and one end of the joint member is provided with a biasing means for biasing the unloading wedge toward the anchor head.
The anchor unloading jig according to claim 1, wherein the anchor is forcibly unloaded. The ram chair, which is a reaction member in the jack means, is a cylindrical body, and the side wall is provided with a window that allows the release pipe to be inserted into the hole of the anchor head while surrounding the outer peripheral surface of the anchor cable. Being done,
The anchor unloading jig according to any one of claims 1 to 3. The inner wall surface of the ram chair is provided with a lifting prevention means for preventing the anchor head from floating from the fixing portion due to the tensile force of the jack means.
The anchor unloading jig according to any one of claims 1 to 4, wherein: Each outer peripheral portion of the release pipe divided body is provided with an attaching means for detachably attaching a handle member for safety work,
The anchor unloading jig according to any one of claims 1 to 5, wherein: Forming the anchor unloading jig according to any one of claims 1 to 6,
After the release pipe is inserted into the hole of the anchor head, the unloading wedge is prevented from moving to the anchor head side by the protrusion at the other end of the release pipe, and the unloading wedge and the tensile force are released. The tension of the anchor cable is unloaded by releasing the tension restraint state of the unloading wedge by relative movement with the coupler case.
An anchor unloading method characterized by At the end of the ram chair, a supporting plate for securing the supporting pressure by the jack of the jack means is provided, and the pulling work by the jack is performed,
The method for forcibly unloading anchors according to claim 7. While the anchor head is prevented from being lifted from the fixing part by the pulling force of the jack means by the lifting prevention means provided on the inner wall surface of the ram chair, the anchor cable is pulled by the jack means to lift the fixing wedge. Removing,
The method for forcibly unloading anchors according to claim 7 or 8.

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