JP4367930B2 - Re-tensioning method for existing anchors, anchor re-tensioning jig, and anchor head also serving as a re-tensioning member - Google Patents

Description

  The present invention relates to a method for re-tensioning an anchor for re-tensioning an existing anchor that has been constructed and anchored, an anchor re-tensioning jig used for re-tensioning the anchor, and a re-tensioning member that can also be used as the re-tensioning member It relates to the anchor head.

Anchors constructed for the purpose of reinforcing and stabilizing the ground, structures, etc., so-called ground anchors, are generated by the pulling and tension of the free length of the tension material anchored (consolidated) at the tip of the ground. It is a structure that transmits and imparts the tension force to the ground, structures, etc. as its anchoring force, so if the tension force decreases due to the displacement of the ground etc. due to secular change or the elongation of the tensile material, its function as an anchor Accompanied by a decline in sex. Therefore, usually, the soundness level is inspected almost regularly, and when it is determined that the tension is reduced, the anchor function is maintained for a long time by re-tensioning the anchor. ing.

  Here, when the existing anchor is re-tensioned, a hydraulic center hole jack capable of generating a great traction force is generally used.

  As an example of this re-tensioning method using a center hole jack, for example, the one disclosed in JP-A-11-209974 is cited. In this known re-tensioning method, a large diameter long bolt is screwed into a central screw hole formed in advance in the anchor head, and the long bolt is pulled by a center hole jack placed on a ram chair. It is intended to re-tension the tensile material, that is, the anchor.

  By the way, the above-mentioned general center hole jack used for tension at the time of anchor construction or re-tensioning of an existing anchor can be recognized as a relatively heavy heavy-duty equipment, and it requires a considerable amount of labor to move and install it. This is a general recognition of the center hole jack.

  Here, even if the equipment is relatively heavy, use a center hole jack for tensioning and fixing the tension material if the work environment is in the initial construction with construction facilities such as scaffolding and cranes. I can't feel much inconvenience. However, existing anchors that require re-tensioning are usually in an environment after the removal of construction equipment such as scaffolds and cranes, so when re-tensioning existing anchors, they can withstand the movement and installation of the center hole jack. Since it is required to reproduce construction equipment equivalent to that at the time of initial construction, such as construction of a large-scale scaffolding to be obtained and crane installation, it takes considerable effort and time to re-tension existing anchors. It is generally recognized as a thing.

  That is, in the conventional re-tensioning method using the center hole jack, an increase in the work cost is inevitable.

  In some cases, due to environmental changes around the site with the passage of time, the construction equipment may become unreproducible, so the conventional re-tensioning method using a center hole jack is It cannot be denied that it is inferior in adaptability to on-site environmental changes.

Further, in the re-tension method disclosed in the above-mentioned JP-A-11-209974, it is necessary to use an anchor head in which a screw hole is formed in advance at the time of its initial construction, so it does not have a female screw hole. It must be considered that this re-tensioning method cannot be applied to the current anchor head that has already been constructed, and it cannot be denied that its adaptability and versatility are inferior.
JP-A-11-209974

  The problem to be solved is that a center hole jack is used and that it cannot be applied to an existing anchor head that has already been installed.

  The re-tensioning method for an existing anchor according to the first aspect of the present invention enables a re-tensioning member having through holes serving as screw holes at three or more positions apart from each other, and can be moved integrally with a tensile material in at least the pulling direction. It is most important that the re-tensioning member is moved axially in the pulling direction under the screwing of a series of tension bolts inserted through the through-holes of the re-tensioning member from the end side of the tension member and screwed. Features.

  Further, the re-tensioning method for the existing anchor according to claim 2 is associated with the protrusion of the tension bolt from the re-tensioning member toward the bearing plate under the screw advancement with respect to the through hole as the screw hole in claim 1. The most important feature is that the tension material is pulled and held in the tension direction by pushing up the re-tensioning member with respect to the bearing plate by the tension bolt.

  Furthermore, the method for re-tensioning an existing anchor according to claim 3 is characterized in that, in claim 1, a tension bolt is rotatably inserted into and held by a bolt base arranged by grounding to the bearing plate, and the bolt base is The tension material is pulled in the tension direction by pulling up the re-tensioning member with respect to the bearing plate by this tension bolt under the threading of the through hole as a screw hole with the rotation of the tension bolt as the support base. Towing and holding is the most important feature.

  According to another aspect of the present invention, there is provided a method for re-tensioning an existing anchor, wherein the support head fixedly connected to the existing anchor head is at least integrally movable in the pulling direction. This is the main feature.

  Further, the method of re-tensioning an existing anchor according to claim 5 further comprises a support head fixedly connected to the extending end of the tension member from the anchor head so as to be able to move at least in the pulling direction. The main feature is that it is a re-tensioning member of 1 to 3.

  According to a sixth aspect of the present invention, the existing anchor head is provided with a through-hole serving as a screw hole in advance, so that the anchor head itself is used as the second tension member according to the first to third aspects. As its most important feature.

  Further, in the anchor re-tensioning jig according to the present invention according to claim 7, the through-holes defined as screw holes having at least part of the female thread portion are separated at three or more positions in the non-aligned position with the anchor head. The re-tensioning is connected to the anchor head and any one of the extension ends of the tensile material from the anchor head so that the anchor head can be integrally moved at least in the pulling direction by a predetermined connecting means. A support head that is a member, and a series of tension bolts that are inserted into and screwed into the through-holes that serve as screw holes of the support head, and the support head that is screwed into the through-holes As the tension bolt protrudes from the bearing plate toward the bearing plate, the tension bolt pushes the support head against the bearing plate with this tension bolt, and the tension material is pulled in the tension direction. Traction and holds, that is configured as a push-up type, and its most important features.

  The anchor re-tensioning jig according to claim 8 is formed in a substantially ring shape that can be interposed between the bearing plate and the support head around the anchor head, and a predetermined screw portion is provided on the outer peripheral surface thereof. And an internal sealed head cap having a corresponding threaded portion that can be screwed to a threaded portion on the outer peripheral surface of the base on the inner peripheral surface of the lower end portion, The top surface of this pedestal is defined as the grounding surface at the tip of the tension bolt on the side of the bearing plate, and this pedestal is a head for post-tensioning that protects the head anchoring part of the existing anchor after retensioning against rust. The most important feature is that it is a base for attaching the cap.

  Further, the anchor re-tensioning jig according to the present invention according to claim 9 has three or more through-holes defined as screw holes each having at least a female thread portion separated from each other at a position not aligned with the anchor head. The re-tensioning is connected to the anchor head and any one of the extension ends of the tensile material from the anchor head so that the anchor head can be integrally moved at least in the pulling direction by a predetermined connecting means. A support head as a member, a bolt base arranged to cover at least the anchor head and the support head under grounding to the bearing plate, and a bolt that is suspended and supported rotatably through the insertion. A series of tension bolts inserted and screwed into the support head through hole through the upper end surface of the base, and the rotation of the tension bolt using the bolt base as a support base It was constructed as a lifting mold that pulled and held the tension material in its tension direction by pulling up the support head with respect to the bearing plate by this tension bolt under the screwing with respect to the through hole. The most important feature.

  The anchor re-tensioning jig according to claim 10 further includes an internal hermetic cap body that covers the upper portion of the bolt base in a closed manner, and the cap body is combined with the bolt base. Thus, the main feature is that this is used as a head cap for re-tensioning for protecting the head anchoring portion of the existing anchor after re-tensioning for rust prevention.

Further, in the anchor re-tensioning jig according to the eleventh aspect of the present invention, the anchor head has the through-holes defined in advance as screw holes each having at least a female thread portion at three or more spaced positions in advance. As a member, a series of tension bolts are inserted and screwed into the through holes as screw holes of the anchor head, and the series of tension bolts inserted and screwed into the through holes from the end side of the tensile material are anchor heads. The main feature is that the tension member can be pulled and held in the tension direction by moving the anchor head in the pulling direction with respect to the bearing plate by being screwed with respect to the through hole.

  Furthermore, the anchor re-tensioning jig according to claim 12 is the structure according to claim 11, wherein the tension bolt is screwed into the through hole so as to be able to protrude in the direction of the bearing plate from the anchor head, and is screwed into the through hole. A push-up type that pulls and holds the tension material in the tension direction by pushing up the anchor head against the bearing plate with this tension bolt along with the projection of the tension bolt in the direction of the bearing plate from the anchor head The main feature is that it is configured as.

  Then, the anchor re-tensioning jig according to claim 13 is configured to insert and hold the tension bolt rotatably with respect to a predetermined bolt base arranged by grounding to the bearing plate in the configuration of claim 11. The tension material is pulled and held in the direction of tension by pulling up the anchor head with respect to the bearing plate by this tension bolt under the threading of the through hole with the rotation of the tension bolt with the bolt base as the support base. The main feature is that it is configured as a pull-up type.

  Further, the re-tensioning member combined anchor head of the present invention according to claim 14 is a re-tensioning member having in advance at least three through-holes defined as screw holes having at least part of the female screw part, The tension material can be re-tensioned by moving a series of tension bolts inserted and screwed into the through-hole from the end side of the tensile material to the through-hole and moving the axis in the pulling direction with respect to the bearing plate. This is the main feature.

  Further, the re-tensioning member combined anchor head according to claim 15 is characterized in that, in the structure of claim 14, the insertion path that allows the insertion of the non-circular nut member from the side end opening can regulate the rotation of the nut member. The nut member is provided in communication with a part of the through hole, and the nut member is aligned and arranged from the insertion path to the through hole, so that the nut member can be defined and arranged as a female screw portion of the through hole. This is the main feature.

  According to the re-tensioning method for an existing anchor of the present invention according to claims 1 to 3, the re-tensioning operation for the existing anchor can be performed under the screwing of the tension bolt with respect to the re-tensioning member. However, there is an advantage that it becomes possible easily without using large equipment such as a center hole jack.

  And since it becomes possible to re-tension existing anchors that do not use large equipment such as center hall jacks, the movement and installation labor of equipment during re-tensioning of existing anchors is greatly reduced. Since the construction of a large-scale scaffolding necessary for installation is not required when the existing anchor is re-tensioned, the labor during the work can be greatly reduced, and the work cost is also greatly reduced. This advantage is also obtained by this existing anchor re-tensioning method.

  Further, since it is sufficient to rotate the tension bolt in the tightening direction with a torque wrench or the like, parallel work by a plurality of workers can be performed on a plurality of existing anchors. That is, since the re-tensioning work for a plurality of existing anchors can be performed simultaneously, reduction of work cost by shortening the overall work time can also be obtained as an advantage of the present invention.

  Furthermore, if the tension bolt is maintained in its screwed state, the re-tensioning member, i.e., the tensile material is held in the re-tensioned state, so that a separate member such as a spacer for filling the gap becomes unnecessary, and Since simplification can be sufficiently obtained, according to the present invention, there is an advantage that the workability is surely improved.

And since it is the pulling of the tension | tensile_strength member via a re-tensioning member, it becomes possible to perform the retraction | tension and re-tension, without adding any hand to the existing anchor head. In other words, since it can be applied to an anchor head of the current form that does not consider its connection at all, the existing existing anchor using the current anchor head can be the target of re-tensioning. The advantage that the versatility is reliably improved can be obtained according to the present invention.

  Further, according to the re-tensioning method of the existing anchor according to claim 2, since it is sufficient to screw the tension bolt directly into the through hole of the re-tensioning member, there is an advantage that the configuration can be simplified. is there.

  According to the method for re-tensioning the existing anchor according to the third aspect, since the load in the pulling direction is applied to the tension bolt, an increase in the support load by the tension bolt can be sufficiently expected. That is, there is an advantage that a re-tensioning method that can be used particularly effectively is obtained when the tensile load during re-tensioning is large and when the pulling length is long.

  And in the structure of Claim 4, since the support head fixedly connected with the existing anchor head is actualized as a re-tension member, according to this, the operation | work of the work is not accompanied by complication of a structure. The advantage that simplification is sufficiently possible is obtained.

  Further, in the configuration of claim 5, since the support head fixedly connected to the extending end of the tensile material from the existing anchor head is embodied as the re-tensioning member, according to this, the configuration is complicated. Therefore, there is an advantage that simplification of the work can be sufficiently performed without any change.

  Furthermore, in the structure of Claim 6, since the existing anchor head itself is used as the re-tension member, there exists an advantage that the structure is simplified easily.

  Further, according to the anchor re-tensioning jig of claim 7, there is an advantage that the re-tensioning method of claim 1 and claim 2 can be appropriately performed without complicating the configuration.

  And according to the structure of Claim 8, the anticorrosion protection of the head fixing | fixed part after the re-tensioning in the jig for anchor re-tensioning of Claim 7 can be easily performed without complication of a structure. There are advantages.

  Further, according to the anchor re-tensioning jig of claim 9, there is an advantage that the re-tensioning method of claim 1 and claim 3 can be appropriately performed without complicating the configuration.

  And according to the structure of Claim 10, the anticorrosion protection of the head fixing | fixed part after the re-tensioning in the jig for anchor re-tensioning of Claim 9 becomes easy easily without complication of a structure. There are advantages.

  Further, according to the anchor re-tensioning jig of claim 11, there is an advantage that the re-tensioning method of claim 1 can be appropriately performed without complicating the configuration.

  And according to the structure of this Claim 11, since anchor head itself is utilized as a re-tensioning member, there exists an advantage that a structure is simplified reliably.

  Moreover, according to the structure of Claim 12, there exists an advantage that the re-tensioning method of Claim 1 and Claim 2 can be performed appropriately, without complicating a structure.

  Furthermore, according to the structure of Claim 13, there exists an advantage that the re-tensioning method of Claim 1 and Claim 3 can be performed appropriately, without complicating a structure.

  According to the anchor head combined with the re-tensioning member according to claim 14, the advantage that the re-tensioning method according to claims 1 to 3 can be appropriately performed without complication of the configuration, and claims 11 to The advantage that the 13 anchor re-tensioning jigs can be appropriately configured is obtained.

  Furthermore, according to the structure of Claim 15, since the internal thread part of a through-hole is a separate nut member which can be retrofitted, the generation | occurrence | production of the rust accompanying the secular change from the time of construction in the internal thread part is produced. Since it can be reliably prevented, smooth screwing of the tension bolt at the time of re-tensioning can be easily ensured, so that the workability and the certainty of the work are improved.

  The purpose of re-tensioning an existing anchor without using a center hole jack can be realized without complicating the structure.

  In addition, the adaptability to the current anchor head can be improved at the same time.

  1 to 3 show a first embodiment of an anchor re-tensioning jig 10 according to the present invention. And, as can be seen by comparing the schematic longitudinal sectional view before re-tensioning shown in FIG. 1 with the schematic longitudinal sectional view after re-tensioning shown in FIG. 2, the anchor re-tensioning jig of the present invention 10 is configured such that an existing anchor, that is, its tension member 18 is pulled and re-tensioned by screwing a series of tension bolts 16 toward a bearing plate 14 with respect to a predetermined re-tensioning member.

  As shown in FIG. 4, an anchor (ground anchor) constructed for the purpose of reinforcing and stabilizing the ground, structures, etc. is a tension member 18 having a fixing portion (not shown) consolidated in the ground, for example, A predetermined plurality of PC steel strands are pulled under a predetermined traction force, and an anchor head 22 that can be placed on and engaged with the bearing plate 14 on the structure 20 is extended by a wedge 24 with respect to the extended end 18a. By being fixedly locked, the tension force can be applied to the structure and the ground as a fixing force, but the overall basic structure is known and the structure itself is not the gist of the present invention. Therefore, a detailed description of the structure is omitted here.

  Note that reference numeral 26 indicated by a one-dot chain line in FIG. 4 indicates an internally sealed head for protecting the head fixing portion 28, that is, the upper portion of the bearing plate 14 mainly composed of the anchor head 22, after the anchor construction. It is a cap, and this head cap is normally detachably attached to the pressure bearing plate by bolting or the like.

  The anchor re-tensioning jig 10 according to the present invention pulls the head fixing portion 28 of the anchor (existing anchor) thus constructed, thereby re-tensioning, that is, re-tensioning the tension member 18. As shown in FIGS. 1 and 2, in this first embodiment, the re-tensioning is performed by pushing up the re-tensioning member with respect to the bearing plate 14 as the series of tension bolts 16 are screwed. It is supposed to be.

  The re-tensioning member is connected to the anchor head 22 or the extended end 18a of the tension member 18 extending from the anchor head by a predetermined connecting means so as to be able to move at least in the pulling direction. As shown in FIGS. 1 and 3, here, first, a substantially ring-shaped support head 32 fixedly connected to the anchor head is specifically exemplified as the re-tensioning member.

  The support head (re-tensioning member) 32 is a substantially ring-shaped body that can be arranged around the existing anchor head 22, and the through-holes 34 extending in the direction along the axis thereof are separated at three or more locations, for example, It is formed at equal intervals.

  As can be seen from FIG. 3, in this embodiment, the number of through holes 34 of the support head is embodied as twelve places with an interval of approximately 30 °.

  As can be seen from FIG. 1, the through hole 34 of the support head is defined and formed as a screw hole having at least a partial female thread portion 34a therein, and the tensile member 18 of the tension member 18 with respect to the thread portion is formed. For example, a corresponding number of tension bolts 16 are arranged on the distal side, that is, under direct insertion and screwing from above in the drawing.

  The support head 32 is disposed around the existing anchor head 22, and is connected to the anchor head by a predetermined connecting means so as to be able to move integrally in at least the pulling direction.

  As can be seen from FIG. 3 in addition to FIG. 1, as this connecting means, for example, an arc-like shape corresponding to a plane inserted between the anchor head 22 and the support head 32 in the drawing, that is, from the distal end side of the tensile material. A series of wedges 30 can be illustrated.

  When the wedge 30 is used as the connecting means, the inner peripheral surface 32a of the support head 32 is formed as a tapered surface with the upper end inclined outward (see FIG. 1).

  Here, when this type of anchor (existing anchor) is re-tensioned, it is necessary to provide a head cap for rust prevention protection for the head fixing portion 28 after the re-tension. However, in this configuration in which the support head 32 is arranged around the existing anchor head 22, there is a possibility that the head cap (reference numeral 26 in FIG. 4) at the beginning of construction cannot be reused. Therefore, as shown in FIGS. 1 to 3, in this embodiment, assuming that the head cap (reference numeral 26 in FIG. 4) at the beginning of construction cannot be reused, the head cap mounting base after re-tensioning The pedestal 36 is provided as a constituent member of the anchor re-tensioning jig 10.

  As shown in FIGS. 1 and 3, the pedestal 36 is formed as a substantially ring-like body similar to the support head 32 and can be disposed around the existing anchor head 22. 14 and the support head.

  The pedestal 36 is abutted and grounded at the tip of the tension bolt 16 projecting from the support head 32, and the tension bolt can ensure the function as the pedestal for supporting the tension bolt. It has a width and rigidity capable of grounding.

  The assembly structure of the anchor re-tensioning jig 10 is shown in FIG. Then, the existing anchor by the anchor re-tensioning jig 10 arranged with such an assembly, that is, the re-tension of the tension member 18 is caused by the tension bolt from the end of the tension member to the female thread portion 34a of the support head. This is done under 16 screws.

  That is, after fixed connection of the support head 32 around the anchor head 22 by the wedge (connection means) 30, each tension bolt 16 is screwed under a rotation operation in the tightening direction by a torque wrench or the like, As shown in FIG. 2, the tip of each tension bolt protrudes from the support head in the direction of the support plate 14, in this case, in the base direction at the ground contact portion with the base 36, thereby pushing up the anchor head with respect to the support plate, that is, a tensile material 18 re-tensioning takes place.

  In addition, by setting the tightening torque for each tension bolt 16 in advance with a torque wrench or the like, the uniform traction and tension can be easily secured.

  As described above, in the method for re-tensioning the existing anchor of the present invention, the tension bolt 16 screwed and disposed on the support head 32 is merely rotated in the tightening direction by a torque wrench or the like. Re-tensioning work on the anchor can be easily performed without using large equipment such as a center hole jack.

  That is, according to the present invention, the existing anchor can be re-tensioned without using large equipment such as a center hole jack, so that the movement and installation labor of the equipment when the existing anchor is re-tensioned are greatly reduced. And since the construction of a large-scale scaffolding necessary for the movement and installation of large equipment is not necessary when the existing anchor is re-tensioned, the labor during the work can be greatly reduced from this point, The work cost is also greatly reduced.

  Further, in the present invention, it is sufficient to rotate the tension bolt 16 in the tightening direction with a torque wrench or the like, so that a plurality of workers can perform parallel work on a plurality of existing anchors. That is, since the re-tensioning work for a plurality of existing anchors can be performed simultaneously, the overall work time can be shortened, and the work cost is also sufficiently reduced in this respect.

  Furthermore, according to the present invention, if the tension bolt 16 is maintained in its screwed state, the anchor head 22, that is, the tension member 18 is held in the re-tensioned state. A member becomes unnecessary, Therefore The workability | operativity is improved reliably.

  Even if the structure 20 and the tension member 18 are inclined due to the displacement of the ground or the like, the anchor head 22 can be held at an angle corresponding to the inclination by adjusting the protruding amount of each tension bolt 16. Therefore, it is not necessary to add an angle adjusting member such as an adjuster. Therefore, according to the present invention, the configuration can be sufficiently simplified.

  Then, according to the anchor re-tensioning jig 10 according to the first embodiment of the present invention described above, the above-described existing anchor re-tensioning method can be easily and appropriately performed without complicating the configuration. .

  Further, in the anchor re-tensioning jig 10, the support head 32 is fixedly connected to the existing anchor head 22 by the wedge 30. In other words, since it can be applied to an anchor head of the current form that does not consider its connection at all, the existing existing anchor using the current anchor head can be the target of re-tensioning. The versatility is reliably improved.

  Here, as described above, in the anchor re-tensioning jig 10 of this embodiment, the pedestal 36 serving as a mounting base for the head cap for re-tensioning is disposed on the bearing plate 14. Therefore, in the anchor re-tensioning jig 10 of this embodiment, after the existing anchor is re-tensioned, an internal sealed head cap 38 is attached so as to cover the head fixing portion 28 by using this pedestal 36 ( (See FIG. 2).

  As can be seen from FIG. 3, the pedestal 36 is formed with a threaded portion 40 on the outer peripheral surface thereof. Then, a head cap 38 having a screw portion 42 corresponding to the screw portion 40 on the inner peripheral surface of the lower end is screwed around the pedestal 36 as shown in FIG. Rust prevention protection of the rear head fixing unit 28 becomes possible.

  In addition, since the pedestal 36 to which the tension bolt 16 is grounded is pressed against the bearing plate 14 under the tension force of the tension bolt, the pedestal 36 is fixed on the bearing plate without any other fixing. Its fixed retention is ensured.

  Also, reference numeral 44 in FIG. 2 is a waterproof rubber packing provided on the lower surface of the head cap 38.

  Here, in the above embodiment, the screwing to the pedestal 36 interposed between the bearing plate 14 and the support head 32 is embodied as an attachment form of the head cap 38 after the anchor re-tensioning. It is only an example, and is not limited to this form. For example, a form in which the head cap 38 after anchor re-tensioning is attached under direct bolting to the bearing plate 14 is another example of the attachment form.

  If the head cap 38 is attached without using the pedestal 36, this pedestal can be omitted from the anchor re-tensioning jig 10.

  However, if the ring-shaped pedestal 36 is interposed between the bearing plate 14 and the support head 32 as in this embodiment, the pedestal serving as the mounting base of the head cap 38 is the anchor re-tensioning jig. Therefore, the head cap can be easily attached without complicating the structure. Since the head cap 38 can be attached without any effort to the constituent members of the existing anchor, the workability thereof is also improved with certainty.

  Further, in this embodiment described above, the number of tension bolts 16, that is, the number of support head through-holes 34, is embodied as 12 separated by 30 °. As a result, it is sufficient that there are three or more places that can stably support the tension member 18, and the present invention is not limited to these twelve places.

  However, as the number of tension bolts 16 increases, the load applied to each tension bolt is dispersed, and the shared load per one decreases. Therefore, the larger the number of tension bolts, the corresponding load, that is, the tension load. Can be set large.

  Further, in this embodiment, the tension bolts 16 are disposed over the entire number of the through holes 34 of the support head. However, since the number of tension bolts disposed on the support head 32 may be three or more, the through holes are sufficient. The arrangement of the tension bolts with respect to the total number is not particularly required.

  Further, in this embodiment, the female screw portion 34a of the support head is embodied as a part of the through hole 34. However, the present invention is not limited to this. For example, the female screw portion is provided in the entire region in the axial direction. It may be provided. However, since it is sufficient that the internal thread portion 34a of the support head has a length that can withstand the torque at the time of re-tensioning the existing anchor, the entire length of the through hole 34 does not need to be the internal thread portion, By shortening the length, the forming work and the screwing work can be facilitated, and the workability is improved.

  Here, the wedge 30 is used in the above-described embodiment as a connecting means for fixedly connecting the support head 32 around the existing anchor head 22 so that the support head 32 can be integrally moved in the pulling direction. It is not limited to.

  For example, as shown in FIGS. 5 and 6, there is an existing form of an anchor head 22 of an existing anchor, for example, having a threaded portion 46 on its peripheral surface. A threaded portion 48 corresponding to the threaded portion 46 of this circumferential surface provided on the inner circumferential surface of 32 can be embodied as a connecting means for fixedly coupling the support head to the anchor head.

  In this way, if the corresponding threaded portion 48 that can be screwed to the threaded portion 46 of the anchor head is used as the coupling means, at least the anchor head 22 and the support head 32 can be connected to each other under the mutual screwing. Since the integral movement in the pulling direction can be ensured, as shown in FIG. 7, the existing anchor head 22 is pushed up as the tension bolt 16 is screwed with respect to the female screw portion 34a of the support head, that is, the tension member 18 is moved again. Tension can be secured in the same manner as in the above embodiment.

  Thus, by using the threaded portion 46 provided in advance on the existing anchor head 22, separate connecting means such as wedges are not required, and the number of parts can be reduced. Therefore, simplification of the configuration and simplification of the operation can be obtained.

  In addition, about the same component as the said Example, the same referential mark is attached | subjected in FIG. 5 thru | or FIG. 7, and the description here is abbreviate | omitted.

  Further, as described above, the re-tensioning member for re-tensioning the existing anchor is fixedly connected to either the anchor head 22 or the extension end 18a of the tensile material from the anchor head. Therefore, the support head is not limited to a support head that is fixedly connected to the anchor head as described above. 8 to 10 show an example in which the support head 50 fixedly connected to the extending end 18a of the tensile material is a re-tensioning member.

  As can be seen from FIGS. 8 and 9, this support head (re-tensioning member) 50 has a corresponding number of insertion holes 52 through which the extension end 18 a of the tensile material can be inserted at the center thereof. The wedge head 54 is fitted around the tension member in the insertion hole, whereby the support head is integrally connected to the tension member using the wedge as a connecting means.

  Also in this configuration, a substantially ring-shaped pedestal 36 is disposed around the anchor head 22 between the bearing plate 14 and the support head 50, and a series of tension bolts 16 abut against the pedestal and are grounded. Thus, the tension bolt 18 can be re-tensioned as the support head is pushed up against the bearing plate as shown in FIG. 10 by screwing the tension bolt with respect to the through hole 34 of the support head.

  Then, by providing the threaded portion 40 on the outer peripheral surface of the pedestal 36, it is possible to easily attach the head cap 38 after the anchor re-tensioning as in the above embodiment.

  In this way, when the extension length of the tension member 18 from the anchor head 22 is appropriate, the extension end 18a of the tension member can be used for traction. That is, even in this configuration, it is possible to easily re-tension the anchor without adding any hand to the anchor head 22 of the current form.

  Moreover, in such a case, since the tension member 18 can be pulled and re-tensioned regardless of the shape and form of the existing anchor head 22, the shape and form of the anchor head are special. In particular, it can be used effectively.

  The embodiments described so far are embodied as a so-called push-up type in which the support head is pushed up against the pressure plate 14 under a series of tension bolts 16 screwed to the support head (restensioning member). However, the present invention is not limited to this, and the anchor re-tensioning jig may be configured in a so-called pulling die that re-tensions the existing anchor, that is, the tension member 18 under a series of tension bolts.

  The pulling-type anchor re-tensioning jig 110 is a second embodiment of the present invention, and an example thereof is shown in FIGS.

  As shown in FIGS. 11 and 12, for example, a substantially ring-shaped support head 32 disposed around the existing anchor head 22 can be integrally moved at least in the pulling direction by a wedge (connecting means) 30. Fixedly connected to the anchor head. A bolt base 56 is disposed with grounding to the bearing plate 14 so as to cover the anchor head 22 and the support head 32.

  The bolt base 56 is formed in a hollow trapezoidal shape closed at least on its side surface, and a series of tension bolts 16 inserted into and screwed into the through holes 34 of the support head are rotatably inserted and held at the upper end thereof. Has been.

  An assembly structure of the anchor re-tensioning jig 110 is shown in FIG. Then, the re-tensioning of the existing anchor, that is, the tension member 18 by the anchor re-tensioning jig 110 arranged with such assembly is performed on the internal thread 34a of the support head in the same manner as in the first embodiment. The tension bolt 16 is screwed from the end side of the tension material.

  That is, when the tension bolts 16 screwed to the female threaded portion 34a of the support head via the bolt base 56 are rotated in the tightening direction, respectively, the tension bolt 16 is rotated with respect to the female threaded portion, as shown in FIG. As shown in FIG. 2, the support head 32 is axially moved together with the existing anchor head 22 in the pulling direction from the bearing plate 14, whereby the tension member 18, that is, the existing anchor is re-tensioned.

  As described above, in the anchor re-tensioning jig 110 having this configuration, the tension member 16 is re-tensioned by screwing the tension bolt 16 with respect to the support head 32 serving as the re-tensioning member. The existing anchor can be re-tensioned properly.

  Since the existing anchor is re-tensioned by rotating the tension bolt 16 with a torque wrench or the like, it is the same as in the first embodiment. Therefore, the re-tensioning operation for the existing anchor is also performed in the second embodiment. Can be easily achieved without using large equipment such as a center hole jack. Therefore, the same effect as that of the first embodiment can be easily secured in the anchor re-tensioning jig 110 of the second embodiment. Become.

  Here, as can be seen from FIG. 13, when the existing anchor, that is, the tension member 18 is re-tensioned by the anchor re-tensioning jig 110 of the second embodiment, the tension force from the tension member is changed to the tension bolt 16. Acts as a force pulling in the axial direction. If the load is supported by the tension bolt 16 in the pulling direction, the support force by the tension bolt is higher than that by the tension bolt compression by the anchor re-tensioning jig 10 of the first embodiment. Since it can be kept sufficiently high, it can be used particularly effectively when the tensile load is large and when the pulling length is long.

  Moreover, when using such a bolt stand 56, as shown in FIG. 13, by providing the rubber packing 44 in the lower end, the lower end part can be sealed. Then, by covering the upper part of the bolt base 56 with an internally sealed cap body 58, the combination of the bolt base and the cap body can be used as a head cap for re-tensioning.

  In addition, as a connection means of the cap body 58 with respect to the volt | bolt stand 56, a volt | bolt etc. can be illustrated. Further, reference numeral 60 in FIG. 13 is a waterproof rubber packing provided at the lower end of the cap body 58.

  11 to 13 showing an example of the second embodiment, the wedge 30 is illustrated as a connecting means for fixedly connecting the support head 32 to the anchor head 22. However, the present invention is not limited to this. For example, as shown in FIGS. 14 to 16, when the existing anchor head 22 has a threaded portion 46 on the outer peripheral surface thereof, the inner peripheral surface of the support head 32 is provided. The provided corresponding screw portion 48 can be used as a connecting means between them.

  As shown in FIGS. 14 and 16, even in such a case, the anchor head 22 and the support head 32 are integrally moved in the pulling direction at least under the screwing of the screw portions 46 and 48. Thus, the support head and anchor head can be pulled together by a series of tension bolts 16 rotatably held on the bolt base 56, that is, the tension member 18 can be re-tensioned as described above. .

  Further, as in the first embodiment, the tension member 18 is not limited to being pulled through the anchor head 22, and the tension member 18 can be re-tensioned using the extension end 18a of the tension member from the anchor head 22. is there.

  As can be seen from FIGS. 17 to 19, in this modification, the support head 50 fixedly connected to the extending end 18 a of the tension member using the wedge 54 as a connecting means is connected to the through-hole 34 in a series. It is illustrated as a re-tensioning member to which the tension bolt 16 is screwed. Then, a series of tension bolts that are rotatably inserted into and held by the bolt base 56 are screwed into the through holes 34 of the support head (connecting means) serving as screw holes, and the female screws 34a of the through holes are As the tension bolt is screwed, the support head 50 is axially moved in the pulling direction from the bearing plate 14 as shown in FIG. 19, so that the tension member 18, that is, the existing anchor is re-tensioned.

  By the way, both the above-mentioned first embodiment and second embodiment are intended for re-tensioning of an existing anchor having an anchor head 22 having a current shape and form. That is, the versatility with respect to the current anchor head 22 is reliably improved with the anchor re-tensioning jigs 10 and 110 of the first and second embodiments.

  However, in the case of an anchor to be newly constructed, the shape and form of the anchor head need not be the current one. In such a case, the anchor head itself can be used as a re-tensioning member. It becomes possible.

  An example of such an anchor re-tensioning jig 210 using the re-tensioning member combined anchor head 222 is shown as a third embodiment in FIGS.

  As illustrated, in the anchor re-tensioning jig 210 of the third embodiment, a through hole 34 into which a series of tension bolts 16 are inserted and screwed is formed in the anchor head 222. For example, in a so-called push-up type configuration in which the anchor head 222 is pushed up against the bearing plate 14, a series of tension bolts 16 are connected to the internal threaded portion 34 a of the through hole as shown in FIG. The tip of each tension bolt protrudes in the direction of the bearing plate 14 by screwing under a rotational operation in the tightening direction by a torque wrench or the like, and an anchor for the bearing plate by the corresponding amount. The head is pushed up, that is, the tension member 18 is re-tensioned.

  In the form of the third embodiment, the anchor head 222 itself is used as a re-tensioning member, so there is no additional member as a re-tensioning member. That is, since there is no change in the outer diameter of the head fixing portion 28, as shown in FIGS. 20 and 22, the head cap 26 at the beginning of construction can be sufficiently used even after the anchor is re-tensioned.

  Also in this configuration, since the existing anchor can be re-tensioned by the series of tension bolts 16, the workability is surely improved as in the above embodiments.

  Here, in this configuration, since the anchor head 222 itself is used as a re-tension member, the addition of the member at the time of re-tension is only a series of tension bolts 16. That is, in this configuration, the configuration can be simplified and the cost can be sufficiently reduced by reducing the number of parts.

  Although an example of a push-up type is shown here, as shown in FIG. 23, the anchor head 222 is re-tensioned by using a bolt base 56 that is inserted and held in a series of tension bolts 16 so as to be rotatable. This configuration can be realized as a pull-up type.

  Here, the re-tensioning member / anchor head 222 used in the anchor re-tensioning jig 210 exemplified above has a through hole 34 into which a series of tension bolts 16 are inserted and screwed in advance. However, the threaded portion 34a is not limited to the one provided integrally with the through hole. That is, as the threaded portion of the through hole 34, for example, the re-tensioning member / anchor head 222 may be embodied by using a separate nut member 62 as shown in FIGS.

  As can be seen from FIG. 26 in addition to FIGS. 24 and 25, the re-tensioning member combined anchor head 222 using the separate nut member 62 as the threaded portion of the through hole 34 has a non-circular outer shape from the side end opening. An insertion path 64 that enables insertion of a nut member such as a hexagonal nut member 62 communicates with a part of the through hole, for example, the lower end side, with a width that allows the rotation of the nut member to be restricted. Is provided. The nut member 62 is aligned and arranged from the insertion path 64 to the through hole 34, whereby the nut member is defined and disposed as a female thread portion of the through hole.

  FIG. 26 shows the structure of the head fixing unit 28 at the beginning of construction. As can be seen from this, in this configuration, there is no thread in the through hole 34 of the anchor head 222 at the beginning of construction. When the anchor is re-tensioned after the head cap 26 is removed, the nut member 62 is aligned with the through hole 34 via the insertion path 64 as shown in FIG. 25, and this nut member is shown in FIG. On the other hand, by screwing a series of tension bolts 16 from the end side of the tension member, the anchor head 222 can be pushed up against the bearing plate 14, that is, the tension member 18 can be re-tensioned.

  As described above, in such a configuration, since there is no thread portion in the anchor head 222 at the beginning of construction, rust associated with secular change since construction does not occur in the thread portion. Accordingly, it is possible to easily ensure smooth screwing of the tension bolt 16 at the time of re-tensioning, thereby improving the workability and the certainty of the work.

  In this embodiment, a hexagonal shape is illustrated as the outer non-circular shape of the nut member 62. However, a shape that prevents rotation of the nut member 62 in combination with the insertion path 64 is sufficient. However, the outer shape of the nut member may be a non-circular shape such as a rectangular shape, an elliptical shape, or an oval shape.

  In addition, although an example of a push-up type is shown here, as shown in FIG. 27, a series of tension bolts 16 is rotatably inserted and held by using a bolt base 56, and another pair of nut members 62 is attached. The anchor head 222 that is used and defined as the threaded portion of the through hole 34 can also be easily realized as a pulling die.

  The above-described embodiments are for explaining the present invention, and do not limit the present invention. All modifications, alterations, and the like within the technical scope of the present invention are included in the present invention. It goes without saying that it is done.

  The tensile material is not limited to a strand made of PC steel, and the above configuration can be applied to a PC steel rod, a lock bolt, and the like.

It is a schematic sectional drawing at the time of the assembly | attachment of the jig for anchor re-tensioning concerning 1st Example of this invention. FIG. 2 is a schematic exploded perspective view of the anchor re-tensioning jig shown in FIG. 1. It is a schematic sectional drawing at the time of re-tension of the jig for anchor re-tension shown in FIG. It is a schematic longitudinal cross-sectional view of the said part which shows the head fixing | fixed part of the existing anchor. It is a schematic sectional drawing at the time of the assembly | attachment of the jig for anchor re-tensioning concerning the modification of 1st Example of this invention. FIG. 6 is a schematic exploded perspective view of the anchor re-tensioning jig shown in FIG. 5. It is a schematic sectional drawing at the time of re-tensioning of the jig for anchor re-tensioning shown in FIG. It is a schematic sectional drawing at the time of the assembly | attachment of the jig for anchor re-tensioning concerning another modification of 1st Example of this invention. FIG. 9 is a schematic exploded perspective view of the anchor re-tensioning jig shown in FIG. 8. It is a schematic sectional drawing at the time of re-tensioning of the jig for anchor re-tensioning shown in FIG. It is a schematic sectional drawing at the time of the assembly | attachment of the jig for anchor re-tensioning concerning 2nd Example of this invention. FIG. 12 is a schematic exploded perspective view of the anchor re-tensioning jig shown in FIG. 11. It is a schematic sectional drawing at the time of re-tensioning of the jig for anchor re-tensioning shown in FIG. It is a schematic sectional drawing at the time of the assembly | attachment of the jig for anchor re-tensioning concerning the modification of 2nd Example of this invention. FIG. 15 is a schematic exploded perspective view of the anchor re-tensioning jig shown in FIG. 14. It is a schematic sectional drawing at the time of re-tensioning of the jig for anchor re-tensioning shown in FIG. It is a schematic sectional drawing at the time of the assembly | attachment of the jig for anchor re-tensioning concerning another modification of 2nd Example of this invention. FIG. 18 is a schematic exploded perspective view of the anchor re-tensioning jig shown in FIG. 17. It is a schematic sectional drawing at the time of re-tensioning of the jig for anchor re-tensioning shown in FIG. It is a schematic sectional drawing at the beginning of construction of the re-tensioning member combined anchor head used as the anchor re-tensioning jig according to the third embodiment of the present invention. It is a general | schematic disassembled perspective view of the jig for anchor re-tensioning concerning 3rd Example. It is a schematic sectional drawing at the time of re-tensioning of the jig for anchor re-tensioning shown in FIG. It is a schematic sectional drawing at the time of retensioning of the jig for anchor retensioning concerning the modification of 3rd Example of this invention. In 3rd Example of this invention, it is a schematic sectional drawing at the time of re-tension which shows the example which uses the re-tension member combined anchor head of another form. It is the schematic exploded perspective view seen from the downward direction at the time of using the re-tensioning member combined anchor head shown in FIG. FIG. 25 is a schematic cross-sectional view of an anchor using the re-tensioning member combined anchor head shown in FIG. It is a schematic sectional drawing at the time of the re-tensioning of the jig for anchor re-tensioning based on the modification of 3rd Example using the re-tensioning member combined anchor head shown in FIG.

Explanation of symbols

10, 110, 210 Anchor re-tensioning jig 14 Bearing plate 16 Tension bolt 18 Tension material 22 Existing anchor head 30 Wedge (connection means)
32,50 Support head (re-tension member)
34 Through-hole 34a Female thread part 36 Base 48 Screw part (connection means)
56 Bolt stand 58 Cap body 62 Nut member (Female thread)
64 Insertion path 222 Anchor head also used as a tension member (restension member)

Claims (15)

In an existing anchor re-tensioning method in which an existing tension member fixed and tensioned by a fixed locking of an anchor head that is engaged with and placed on a bearing plate is pulled and tensioned again in the direction of separation of the anchor head from the bearing plate. ,
A predetermined re-tensioning member having through-holes as screw holes at three or more separated positions is provided so as to be able to move integrally with at least the pulling material in the pulling direction,
The axis of the re-tensioning member in the pulling direction with respect to the bearing plate by screwing a series of tension bolts inserted and screwed into the through-hole from the end side of the tension member to the through-hole of the re-tensioning member A method for re-tensioning an existing anchor, wherein the tension member is re-tensioned by movement.   By pushing up the re-tensioning member with respect to the bearing plate by the tension bolt as the tension bolt protrudes from the re-tensioning member toward the bearing plate under screwing with respect to the through hole as a screw hole. The method for re-tensioning an existing anchor according to claim 1, wherein the tension member is pulled and held in the tension direction. The tension bolt is rotatably inserted and held with respect to a predetermined bolt stand arranged by grounding to the pressure plate,
By pulling up the re-tensioning member with respect to the bearing plate by this tension bolt under the threading of the through hole as a screw hole with the rotation of the tension bolt with the bolt base as a support base, The method for re-tensioning an existing anchor according to claim 1, wherein the anchor is pulled and held in the tension direction.   The support head fixedly connected to the existing anchor head so as to be capable of at least integral movement in the pulling direction is used as the re-tensioning member for re-tensioning the tension member by axial movement in the pulling direction. The method for re-tensioning an existing anchor according to any one of 1 to 3.   A support head fixedly connected to the extension end of the tensioning material from the anchor head is re-tensioned by axial movement in the pulling direction so that at least the integral movement in the pulling direction is possible. The re-tensioning method for an existing anchor according to any one of claims 1 to 3, wherein the re-tensioning member is used.   4. The re-tensioning member for re-tensioning the tension member by axial movement in a pulling direction by providing the through-hole serving as a screw hole in the existing anchor head in advance. The re-tension method of the existing anchor as described in any one of. An existing anchor re-tensioning jig for pulling and tensioning an existing tension member fixed and tensioned by a fixed locking of an anchor head to be engaged and placed on a support plate,
Through holes defined as screw holes having at least a female thread portion are provided at three or more spaced positions in a non-aligned position with the anchor head, and the anchor head and the anchor head are separated from the anchor head. A support head serving as a re-tensioning member connected to any one of the extended ends of the tension member so as to be able to move integrally in at least the pulling direction by a predetermined connecting means;
A series of tension bolts inserted into and screwed into the through holes as screw holes of the support head;
And by pushing up the support head with respect to the bearing plate by the tension bolt as the tension bolt protrudes from the support head in the direction of the bearing plate under screwing with respect to the through hole. An anchor re-tensioning jig configured as a push-up type that pulls and holds a tensile material in the tension direction. A pedestal formed in a substantially ring shape that can be interposed between the bearing plate and the support head around the anchor head, and provided with a predetermined threaded portion on an outer peripheral surface thereof;
An internally sealed head cap having a corresponding threaded portion that can be screwed to a threaded portion on the outer peripheral surface of the pedestal on the inner peripheral surface of the lower end portion;
Further comprising
The top surface of the pedestal is defined as a ground contact surface on the side of the pressure plate at the tip of the tension bolt. The anchor re-tensioning jig according to claim 7, wherein the anchor re-tensioning jig is used as a mounting base of the head cap. An existing anchor re-tensioning jig for pulling and tensioning an existing tension member fixed and tensioned by a fixed locking of an anchor head to be engaged and placed on a support plate,
Through holes defined as screw holes having at least a female thread portion are provided at three or more spaced positions in a non-aligned position with the anchor head, and the anchor head and the anchor head are separated from the anchor head. A support head serving as a re-tensioning member connected to any one of the extended ends of the tension member so as to be capable of integral movement at least in the pulling direction by a predetermined connecting means;
A bolt base arranged to cover at least the anchor head and the support head under grounding to the bearing plate;
A series of tension bolts that are inserted and screwed into the through holes of the support head via the upper end surface of the bolt base that is vertically suspended and supported under the insertion;
And pulling up the support head with respect to the bearing plate by the tension bolt under screwing with respect to the through-hole as the tension bolt rotates with the bolt base as a support base. An anchor re-tensioning jig configured as a pull-up type that pulls and holds the tool in the tension direction. An internal sealed cap body that covers the upper portion of the bolt base in a closed manner;
10. The anchor re-tensioning according to claim 9, wherein the cap body is combined with the bolt base to form a head cap for re-tensioning for protecting the head anchoring portion of the existing anchor after re-tensioning against rust. Jig. An existing anchor re-tensioning jig for pulling and tensioning an existing tension member fixed and tensioned by a fixed locking of an anchor head to be engaged and placed on a support plate,
The anchor head serves as a re-tensioning member having in advance at least three through-holes defined as screw holes each having at least a female thread portion, and a series of tension bolts are provided in the screw holes of the anchor head. Inserted and screwed into the through-hole,
Inserted into the through hole from the end side of the tension member, a series of tension bolts screwed due to be screwed to the through hole of the anchor head, the movement axis of the anchor head of the pulling direction with respect to the bearing capacity plate An anchor re-tensioning jig that can pull and hold the tension material in the tension direction. The tension bolt is screwed into the through-hole so that the tension bolt can protrude from the anchor head in the direction of the bearing plate.
When the tension bolt projects from the anchor head in the direction of the bearing plate under the screwing with respect to the through hole, the tension bolt pushes the anchor head against the bearing plate, thereby pulling the tension member. The anchor re-tensioning jig according to claim 11, which is configured as a push-up mold that is pulled and held in a tension direction. The tension bolt is rotatably inserted and held with respect to a predetermined bolt stand arranged by grounding to the pressure plate,
The tension material is pulled in the tension direction by pulling up the anchor head with respect to the bearing plate by the tension bolt under the threading of the through hole with the rotation of the tension bolt using the bolt base as a support base. The anchor re-tensioning jig according to claim 11, wherein the anchor re-tensioning jig is configured to be pulled up and held. In the anchor head that fixes and tensions the tensile material under the fixed connection to the tensile material with placement and engagement with the bearing plate,
As a re-tensioning member having through holes defined as screw holes having at least a female thread part in advance at three or more spaced positions,
A series of tension bolts inserted and screwed into the through-hole from the end side of the tensile material are screwed into the through-hole to move the axis of the tensile material in the pulling direction with respect to the bearing plate. A re-tensioning member combined anchor head characterized by enabling re-tensioning.   An insertion path that allows the insertion of a non-circular nut member from the side end opening is provided in communication with a part of the through hole in a shape that allows the rotation of the nut member to be restricted. 15. The re-tensioning member combined anchor head according to claim 14, wherein the nut member can be defined and disposed as the female thread portion of the through hole by arranging the nut member in alignment with the through hole from the insertion path.

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