Anchors and their installation tools, and earthquake-resistant reinforcement method for concrete support columns using them

Abstract

To provide a construction method allowing an inner diameter of a blockout part (seat digging part) in a concrete structure in which an anchor is installed to be minimized.SOLUTION: An anchor is provided with an anchor body part 30 in a rod shape inserted in an anchor insertion hole 81; a fixing part 40 arranged at a tip side of the anchor body part 30 and fixing the anchor body part 30 in the anchor insertion hole 81 by being pressed on an inner wall surface of the anchor insertion hole 81 through being enlarged in a state it is inserted to a deep part of the anchor insertion hole 81; and a nut 20 having a circular cross section attached on a head part of the anchor body part 30. The anchor body part 30 comprises a male screw part 31 on an outer peripheral surface at its head side as well as a groove part 32 in a radial direction in a tip surface of the head part. The nut 20 is provided with an insertion hole 22 for insertion of the head part of the anchor body part 30 as well as a female screw part 23 in an inner surface of the insertion hole 22 and an engagement part 21 for engaging a fastening tool 50 on its upper surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an anchor and the The present invention relates to a construction jig and a method for seismic reinforcement of concrete support columns using the same. In detail, for example, when carrying out seismic reinforcement work on a concrete support column, a bulge-stop anchor for a panel installed around the concrete support column is used. and Jigs for installing the anchors (driving jigs, tightening jigs), Using these Concrete support columns (e.g., bridge piers) This concerns earthquake-resistant reinforcement construction methods. [Background technology]

[0002] Conventional nuts are generally hexagonal and are tightened using tools such as a wrench, adjustable wrench, or ratchet. With nuts of this shape, if there is an obstacle around the nut when tightening, it may be impossible to operate the tool handle flush with the nut. When the tool handle gets in the way and tightening is impossible, a box wrench or socket wrench can be used to tighten the nut. However, box wrenches and socket wrenches are also tools that are placed over the nut, so a certain amount of space is required around the nut.

[0003] An example of a situation where an obstacle exists around the nut and the wrench handle cannot be operated on the same plane as the nut is when tightening a hexagonal nut on the bottom of a countersunk concrete hole. In addition, the concrete thickness in the countersunk concrete hole is thinner than in other areas, which raises concerns about structural and durability weaknesses.

[0004] After the nut has been tightened, the area where the hole is drilled is protected by filling it with a filler such as mortar (epoxy resin putty in the underwater area). However, from the perspective of the durability and ease of construction of the structure, it is desirable to make the area where the hole is drilled as small as possible. Note that the minimum diameter of the hole is determined by the outer diameter of the tool, such as a box wrench or socket wrench, which is placed over the outside of the hexagonal nut to rotate it, so a hole larger than the size of the hexagonal nut is required.

[0005] To reduce the inner diameter of the counterbore, the outer diameter of the nut attached to the anchor head can be reduced. However, the nut attached to the anchor head is used to attach and secure the anchor to a covering material such as a precast panel, and must have an outer diameter larger than the inner diameter of the anchor insertion hole. In other words, when using a hexagonal nut as in the past, there is a limit to how small the inner diameter of the counterbore can be in order to avoid interfering with the operation of the tightening tool. Therefore, there was a need for the development of an anchor that can be installed without using tightening tools such as a wrench, adjustable wrench, or ratchet.

[0006] Although not intended to reduce the inner diameter of a counterbore, a technology has been proposed for nuts that can be installed without using tightening tools such as a wrench, adjustable wrench, or ratchet (see Patent Document 1). The technology described in Patent Document 1 relates to a double-nut fastener and dedicated tool for the purpose of anti-theft functions, etc. In this technology, a mating recess or mating protrusion is provided on the top surface of the nut. The nut is then tightened using a dedicated tool with a mating portion that fits into the mating recess or mating protrusion. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2014-15990 A Summary of the Invention [Problem to be solved by the invention]

[0008] As mentioned above, when installing anchors in concrete structures (for example, when reinforcing concrete support columns), it is necessary to tighten the nuts that attach and secure the anchors to covering members such as precast panels. In this case, by using a structure that allows the nuts to be tightened without using tightening tools such as wrenches, adjustable wrenches, or ratchets, the inner diameter of the box punch (counterbores) can be reduced.

[0009] Therefore, instead of the anchors that use conventional hexagonal nuts, it was necessary to develop an anchor with a new configuration and its installation jig. After extensive research, the inventors came up with the idea that by using an installation jig that can be operated from the top side of the nut attached to the anchor, the inner diameter of the box punch (counter boring) can be reduced.

[0010] The present invention has been proposed in view of the above circumstances, and provides an anchor and a method for minimizing the inner diameter of a box drilling (counter boring) for a concrete structure in which the anchor is to be installed. the The purpose of this invention is to provide a construction jig and a method for seismic reinforcement of concrete support columns using the same.

[0011] The technology described in Patent Document 1 relates to nuts and dedicated tools for the purpose of preventing theft, and is not intended to reduce the inner diameter of the box-punched hole (spot excavation) in the concrete structure to which the anchor is to be installed. Therefore, in order to reduce the inner diameter of the box-punched hole (spot excavation) in the concrete structure to which the anchor is to be installed, it is necessary to develop not only the shape of the nut but also the jigs (driving jig and tightening jig) for installing the anchor, and the object of the present invention cannot be achieved unless these technologies are developed comprehensively. [Means for solving the problem]

[0012] The anchor according to the present invention and the The construction jig and the method for seismic reinforcement of concrete support columns using the construction jig have the following features in order to achieve the above-mentioned object. The method for seismic reinforcement of concrete support columns is a construction method for, for example, performing seismic reinforcement of bridge piers, and the anchors and the A distinctive feature of this method is that earthquake-resistant reinforcement work is carried out using construction jigs.

[0013] The present invention The anchor and its installation jig are for driving the anchor into a concrete structure and tightening the anchor into a covering member, and include an anchor, an anchor driving jig, and an anchor tightening jig.

[0014] The present invention The anchor includes a rod-shaped anchor body to be inserted into an anchor insertion hole provided in a concrete structure, a fixing portion provided at the tip of the anchor body located within the anchor insertion hole when the anchor body is inserted into the anchor insertion hole and expanded in diameter while inserted deep into the anchor insertion hole to press against the inner wall surface of the anchor insertion hole and fix the anchor body to the deep part of the anchor insertion hole, and a nut having a circular cross section and attached to the head side of the anchor body opposite to the side where the fixing portion is attached, for attaching the anchor body to a covering member. The anchor body has at least a male thread portion near the tip of the anchor body located within the anchor insertion hole when the anchor body is inserted into the anchor insertion hole, and a male thread portion for attaching a nut near the head on the side opposite to the side where the fixing portion is attached, and further has a groove portion on the end surface of the head on the side where the nut is attached. The nut also has an insertion hole for inserting the head of the anchor body, a female thread portion on the inner surface of the insertion hole, and an engagement portion on the side opposite to the side where it is screwed onto the anchor body, for engaging with a tightening jig.

[0015] The anchor according to the present invention The driving jig has a rod-shaped driving body for driving the anchor, with the anchor body extended by being connected to it, a head insertion hole provided on the side where the driving body is connected to the anchor body for inserting the head of the anchor body, and a protrusion that protrudes into the head insertion hole and engages with a groove provided on the side of the anchor body opposite the side on which the fixing part is attached and on which a nut is attached.When driving the anchor, the head of the anchor body is fitted into the head insertion hole, and the protrusion protruding into the head insertion hole is engaged with a groove provided on the head end face of the anchor body on the side on which the nut is attached, and the head of the driving jig is struck with a striking member, thereby inserting the anchor into the anchor insertion hole and fixing the fixing part in the back of the anchor insertion hole. The anchor tightening jig according to the present invention has a rod-shaped tightening body for attaching a nut to the head of the anchor body and tightening the nut to the anchor body, and an engagement operating part provided on the side of the tightening body where the nut is attached and which engages with an engaging part provided on the side of the nut opposite to the side that is screwed onto the anchor body.The head of the anchor body is caused to protrude into a box cutout provided in a covering member, and the nut is screwed onto the head of the anchor body that protrudes into the box cutout.The operating part is then engaged with the engaging part provided on the side of the nut opposite to the side that is screwed onto the anchor body, and the tightening body is rotated in the tightening direction to tighten the nut attached to the head of the anchor body. Furthermore, the nut has an adhesive portion that is provided on the operating portion of the tightening main body and on the side opposite to the side that is screwed onto the anchor main body, and is opposed to the other and attracts the other, and at least one of the opposed adhesive portions can be a magnet.

[0016] The method for seismic reinforcement of a concrete support column according to the present invention is a method for seismic reinforcement of a concrete support column by installing precast panels containing at least hoop reinforcing bars around the outer periphery of the concrete support column, connecting adjacent precast panels with joints, and filling gaps between the concrete support column and the precast panels with grout material. , using a driving jig The process involves driving in the anchor and fixing it in place, then attaching a nut to the head of the anchor. Tightening jig a step of fastening the head of the anchor to the precast panel by tightening the nut using a concrete support column; and a step of filling grout material into the gap between the concrete support column and the precast panel. When you do this, use an anchor. and preventing bulging of the precast panels. The anchors, driving jigs, and tightening jigs used in this earthquake-resistant reinforcement method for concrete support columns have the above-mentioned configurations. That is, the anchor is configured to include a rod-shaped anchor body to be inserted into the anchor insertion hole provided in the concrete support column, a fixing portion provided at the tip of the anchor body located within the anchor insertion hole when the anchor body is inserted into the anchor insertion hole and expanded in diameter while inserted deep into the anchor insertion hole to press against the inner wall surface of the anchor insertion hole and fix the anchor body to the deep part of the anchor insertion hole, and a nut having a circular cross section and attached to the head side of the anchor body opposite to the side where the fixing portion is attached for attaching the anchor body to a precast panel. The anchor body is configured to at least have a male thread portion near the tip of the anchor body located within the anchor insertion hole when the anchor body is inserted into the anchor insertion hole and a male thread portion for attaching a nut near the head on the side opposite to the side where the fixing portion is attached, and further have a groove portion on the end surface of the head on the side where the nut is attached. The nut is provided with an insertion hole for inserting the head of the anchor body, a female thread portion formed on the inner surface of the insertion hole, and an engagement portion for engaging a tightening jig on the side opposite to the side where the anchor body is screwed. Furthermore, the driving jig for driving the anchor into the anchor insertion hole provided in the concrete support column in the process of driving and fixing the anchor into the insertion hole is configured to have a rod-shaped driving body portion for driving the anchor, which is connected to the anchor body portion to extend the anchor body, a head insertion hole provided on the side where the driving body portion is connected to the anchor body, and for inserting the head of the anchor body, and a protrusion that protrudes into the head insertion hole and engages with a groove provided on the side where the nut is attached, opposite to the side where the fixing portion of the anchor body is attached.In the process of driving the anchor into the insertion hole and fixing it, the head of the anchor body is fitted into the head insertion hole when driving the anchor, and the protrusion protruding into the head insertion hole is engaged with a groove provided in the head end face of the anchor body on the side where the nut is attached, and the head of the driving jig is struck with a striking member, thereby inserting the anchor into the anchor insertion hole and fixing the fixing part in the back of the anchor insertion hole. Also, the tightening jig used to tighten the nut attached to the head of the anchor in the process of fixing the head of the anchor to the precast panel is composed of a rod-shaped tightening body for attaching the nut to the head of the anchor body and tightening the nut into the anchor body, and an engagement operating part provided on the side of the tightening body where the nut is attached and engaging with an engaging part provided on the side of the nut opposite the side that is screwed into the anchor body. Then, in the process of fixing the head of the anchor to the precast panel, the head of the anchor body is protruded into a box cutout provided in the precast panel, a nut is screwed onto the head of the anchor body protruding into the box cutout, the operating part is engaged with the engaging part provided on the side of the nut opposite the side screwed onto the anchor body, and the tightening body is rotated in the tightening direction to tighten the nut attached to the head of the anchor body. [Effects of the Invention]

[0017] The anchor according to the present invention and the According to the construction jig and the earthquake-resistant reinforcement method for concrete support columns using the same, the nut attached to the head of the anchor has a circular cross section and is provided with an engaging portion on the top surface. The driving jig covers the head of the anchor body and has a protrusion that engages with a groove provided in the head of the anchor body, so it can be easily attached to the head of the anchor body and the anchor can be reliably driven into the concrete structure. The tightening jig also On the side opposite to the side where the anchor body is screwed The nut has an operating portion that engages with an engaging portion provided on the nut, and by engaging the operating portion with the engaging portion, the nut can be tightened easily and reliably.

[0018] Furthermore, the protrusion on the driving jig is designed to fit into a groove on the head of the anchor body. Therefore, by engaging the protrusion with the groove and rotating the driving jig around its axis, the anchor body can be rotated. This allows the screw-in length of the anchor body relative to the fixing part to be adjusted, making it possible to appropriately adjust the length (extension) of the anchor body that protrudes into the counterbore.

[0019] By using an anchor equipped with a nut of this shape, the inner diameter of the box cutout (counterbore) to be provided in the covering member when attaching the covering member to a concrete structure can be minimized.

[0020] In addition, such anchors and the Construction jig Using Earthquake-resistant reinforcement work for concrete support columns (bridge piers, etc.) So, In covering members (precast panels) attached to concrete support columns (bridge piers, etc.), the inner diameter of the box cutout (seat excavation) can be minimized, so there are almost no weak points in terms of structure or durability. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 2 is a side view of an anchor according to an embodiment of the present invention. [Figure 2]3A and 3B are a side view and a plan view of a nut used in an anchor according to an embodiment of the present invention. [Figure 3] 1 is a side view and a partially enlarged view of an anchor driving jig according to an embodiment of the present invention. FIG. [Figure 4] 3A and 3B are a side view and a plan view of a nut, respectively, of a tightening jig for an anchor according to an embodiment of the present invention. [Figure 5] 1 is a side view of an anchor tightening jig (with magnet) according to an embodiment of the present invention, and a plan view of a nut. [Figure 6] 1 is an explanatory diagram of an anchor installation method according to an embodiment of the present invention. FIG. [Figure 7] 1 is an explanatory diagram showing a procedure for earthquake-resistant reinforcement work on a bridge pier using anchors according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, anchors and anchor installation jigs according to embodiments of the present invention, and a method for seismic reinforcement of concrete support columns using these, will be described with reference to the drawings. Figures 1 to 7 illustrate anchors and anchor installation jigs according to embodiments of the present invention, and a method for seismic reinforcement of concrete support columns using these. Figure 1 is a side view of an anchor, Figure 2 is a side view (a) and a plan view (b) of a nut, Figure 3 is a side view (a) and a partially enlarged view (b) of a driving jig, Figures 4 and 5 are a side view (a) of a tightening jig and a plan view (b) of the nut, Figure 6 is an explanatory diagram of the anchor installation method, and Figures 7(a) to (f) are explanatory diagrams showing the steps of seismic reinforcement work for bridge piers. Note that the anchor installation jigs refer to anchor tightening jigs and anchor driving jigs.

[0023] <Anchor Overview> The anchor 10 according to the embodiment of the present invention has a circular cross-section, unlike conventional nuts with a hexagonal cross-section. As shown in FIGS. 1 to 6 , a tool (tightening jig 50, 50a) is used to rotate the nut 20 from its top surface, thereby minimizing the opening diameter of the box punch 91 required to install the nut 20. That is, an engagement portion 21 is provided on the top surface of the nut 20, and the nut 20 is rotated using a tool (tightening jig 50, 50a) equipped with an operating portion 51 that engages with the engagement portion 21. The engagement portion 21 on the top surface of the nut 20 may be a hole, a straight groove, a cross groove, or the like, and the tightening jig 50, 50a is equipped with an operating portion 51 shaped to engage with the engagement portion 21. The anchor 10 according to the embodiment of the present invention can be applied to a wide variety of general-purpose construction methods, but is particularly suitable as a "swell-stop" anchor 10 for securing a precast panel 90 in underwater construction for seismic reinforcement of bridge piers (see FIG. 7).

[0024] <anchor> As shown in FIG. 1 , the anchor 10 includes an anchor body 30, a fixing portion 40, and a nut 20. The anchor body 30 is a cylindrical member having a male thread 31 on its outer periphery. The male thread 31 may be provided over the entire anchor body 30, or may be provided only near the head where the nut 20 is screwed in and near the tip where the sleeve 41 is screwed in. The fixing portion 40 includes a cylindrical sleeve 41 and a tapered bolt 42 that expands the sleeve 41 by being pushed into the sleeve 41 from its tip. A female thread 43 is provided on the inner surface of the cylindrical sleeve 41, and the male thread 31 on the outer periphery of the anchor body 30 can be screwed into this female thread 43 to attach the sleeve 41 to the anchor body 30. The tip surface of the head of the anchor body 30 has a groove 32 (a so-called slot).

[0025] Then, as shown in FIG. 6 , the anchor body 30 is pushed into the anchor insertion hole 81 with the fixing portion 40 at the tip, and the anchor 10 is driven into the anchor insertion hole 81 using a driving jig 60. The tapered bolt 42 spreads the sleeve 41, and the outer surface of the sleeve 41 presses against the inner surface of the anchor insertion hole 81, thereby fixing the anchor 10 in the anchor insertion hole 81.

[0026] <Nut> The anchor 10 of this embodiment is particularly characterized by the nut 20 and its installation jigs (driving jig 60, tightening jig 50). As shown in Fig. 2, the nut 20 has a circular cross section, and is provided with an insertion hole 22 at its axial center for inserting the anchor main body 30, and on the inner surface of the insertion hole 22 is provided a female thread portion 23 with which the male thread portion 31 provided on the outer peripheral surface of the anchor main body 30 engages.

[0027] An engagement portion 21 for engaging with an operating portion 51 of a tightening jig 50 is provided on the upper surface of the nut 20. The engagement portion 21 shown in FIG. 2 is configured by providing three recesses with a circular cross section at equal intervals in the circumferential direction on the upper surface of the nut 20. The engagement portion 21 is not limited to the form shown in FIG. 2 and may be in any form as long as it can be accessed from the upper surface side of the nut 20 and the nut 20 can be turned. For example, the engagement portion 21 may be formed by providing a straight groove or a cross groove. The form of the operating portion 51 of the tightening jig 50 is determined according to the form of the engagement portion 21.

[0028] <Driving jig> The driving jig 60 is a jig for inserting the anchor 10, before the nut 20 is attached, into the anchor insertion hole 81 and fixing the fixing portion 40 to the bottom of the anchor insertion hole 81. As shown in FIG. 3(a), this driving jig 60 is equipped with a driving body portion 61, a head insertion hole 62, and a protrusion portion 63. The driving body portion 61 is a rod-shaped portion that extends the anchor body portion 30 to drive the anchor 10, and has an outer diameter slightly larger than that of the anchor body portion 30. The length of the driving body portion 61 is set appropriately so that it is easy for the worker to handle, but is at least longer than the depth of the box punch 91 (counter boring).

[0029] A head insertion hole 62, into which the head of the anchor body 30 is inserted, is provided at the tip of the driving body 61. A protrusion 63 is provided at the bottom of the head insertion hole 62, protruding into the head insertion hole 62 and engaging with a groove 32 (slot) provided in the tip surface of the head of the anchor body 30. As shown in FIG. 3(b), the driving jig 60 of this embodiment is provided with a connecting part 64, which is provided at the tip of the driving body 61 and has an outer diameter smaller than that of the driving body 61, and a fitting part 65 attached to the tip side of the connecting part 64. The protruding length of the protrusion 63 provided on the driving body 61 is shorter than the depth of the groove 32 provided in the anchor body 30.

[0030] Furthermore, a male thread portion 66 is provided on the outer peripheral surface of the connecting portion 64, and a protrusion portion 63 is provided at the tip end of the connecting portion 64. A head insertion hole 62 is formed on the tip side of the fitting portion 65, into which the head of the anchor body 30 is inserted. Furthermore, a female thread portion 67 is provided on the inner peripheral surface of the base end side of the head insertion hole 62 provided in the fitting portion 65, into which the male thread portion 66 provided on the outer peripheral surface of the connecting portion 64 is screwed.

[0031] Then, by aligning the head insertion hole 62 with the tip of the driving body 61 and screwing the male threaded portion 64 into the female threaded portion 67, a driving jig 60 equipped with the head insertion hole 62 and the protrusion 63 can be formed at the tip of the driving body 61. Furthermore, a holder attachment hole 68 for attaching a holder (a holding string or a holding ring) for the driving jig 60 may be provided on the head side of the driving body 61.

[0032] To drive the anchor 10, the head of the anchor body 30 is fitted into the head insertion hole 62 of the driving jig 60, the protrusion 63 protruding into the head insertion hole 62 is engaged with the groove 32 provided in the tip surface of the head of the anchor body 30, and the head of the driving jig 60 is struck with a hammer or the like. At this time, the tip surface of the connecting portion 64 provided on the driving body 61 presses against the tip surface of the head of the anchor body 30, allowing the anchor 10 to be driven deep into the anchor insertion hole 81. As described above, the protruding length of the protrusion 63 is shorter than the depth of the groove 32, so the tip surface of the protrusion 63 does not come into contact with the bottom surface of the groove 32 when the anchor 10 is driven.

[0033] Incidentally, when installing the anchor 10 in a concrete structure 80 (for example, a bridge pier 100), variations can occur in the length (extension) of the anchor body 30 protruding into the box hole 91 (counterbored hole) due to factors such as the drilling depth and drilling accuracy of the anchor insertion hole 81 and the finished accuracy of the existing concrete structure 80 (for example, the bridge pier 100). If the protrusion amount (extension) of the anchor body 30 is small, it will hinder the installation of the nut 20. On the other hand, if the protrusion amount (extension) of the anchor body 30 is large, even if a protective material (filler) is filled into the box hole 91 (counterbored hole), the covering thickness of the protective material will be small, and the protective material will not be able to fully function.

[0034] In this embodiment, the groove 32 provided on the head of the anchor body 30 and the protrusion 63 provided on the driving jig 60 function as a flat-head screw and a flat-head screwdriver, respectively. By using this screwdriver function to adjust the screw-in length of the anchor body 30 into the sleeve 41 of the fixing part 40, the length (extension) of the anchor body 30 protruding into the box cutout 91 (counterbore) can be adjusted appropriately. Note that the length (extension) of the anchor body 30 protruding into the box cutout 91 (counterbore) can be adjusted within the length of the female thread portion 43 provided on the sleeve 41.

[0035] <Tightening jig> The tightening jig 50 is a jig for tightening the nut 20 attached to the head of the anchor body 30. As shown in FIG. 4, the tightening jig 50 comprises a tightening body 52, an operation panel 55 provided at the tip of the tightening body 52, and an operation unit 51 provided on the front surface of the operation panel 55. As shown in FIG. 4, the tightening body 52 is a rod-shaped member, and is provided at its tip with the operation unit 51 that engages with the engagement unit 21 provided on the top surface of the nut 20. As described above, the operation unit 51 consists of protrusions provided at three equally spaced locations circumferentially on the top surface of the nut 20 so as to fit into the engagement units 21, each of which has a circular cross section. Note that if the engagement units 21 provided on the top surface of the nut 20 are straight or cross grooves, the operation unit 51 is composed of straight or cross protrusions that engage with these grooves.

[0036] To tighten the nut 20 attached to the head of the anchor body 30 using the tightening jig 50, for example, the head of the anchor body 30 is protruded into a box cutout 91 (counterbore) provided in the covering member (precast panel 90), and the nut 20 is screwed onto the head protruding into the box cutout 91 (counterbore). Then, the operating part 51 of the tightening jig 50 is engaged with the engaging part 21 provided on the top surface of the nut 20, and the tightening body 52 is rotated in the tightening direction.

[0037] In this embodiment, a bolt mounting hole 54 for mounting a hexagonal bolt 53 is provided in the head of the tightening main body 52, and a female thread is formed on the inner peripheral surface of this bolt mounting hole 54. Then, by screwing the shank of the hexagonal bolt 53 into the bolt mounting hole 54, the hexagonal bolt 53 can be mounted on the head of the tightening main body 52.

[0038] The tightening body 52 of the tightening jig 50 is set to a length that protrudes from the box cutout 91 (counterbore) provided in the covering member (precast panel 90), so that by engaging a tightening tool such as a wrench, adjustable wrench, or ratchet with the hexagon bolt 53 protruding outside the box cutout 91 (counterbore), the tightening jig 50 can be rotated with the tightening tool to tighten the nut 20 attached to the head of the anchor body 30. The length of the tightening body 52 is set appropriately so that it is easy for the worker to handle, but it is at least longer than the depth of the box cutout 91 (counterbore).

[0039] <Tightening jig / adsorption by magnet> An embodiment for easily and reliably engaging a tightening jig with a nut 20 will be described. Note that parts having the same functions as those of the tightening jig 50 described above will be described using the same reference numerals. As shown in FIG. 5, this tightening jig 50a has attraction portions 70a and 70b provided opposite to each other on the operating portion 51 of the tightening main body 52 and the upper surface of the nut 20. At least one of the pair of opposing attraction portions 70a and 70b is formed by a magnet. The rest of the configuration is the same as that of the tightening jig 50 described above.

[0040] In the example shown in Fig. 5, cylindrical magnets (one attraction part 70a) are embedded in three locations at equal intervals in the circumferential direction on the top surface of the nut 20. Metal (the other attraction part 70b) that faces each of the magnets (one attraction part 70a) and that the magnet attracts is attached to the operating part 51. Note that the metal that the magnet attracts is attached to the top surface of the nut 20 to form one attraction part 70a, and the other attraction part is formed by embedding a magnet in the operating part 51. 70bIt may also be possible to use the following.

[0041] Furthermore, magnets may be attached to both the operating part 51 and the upper surface of the nut 20 to form a pair of attraction parts 70a, 70b. In this case, the magnets provided on the operating part 51 and the magnets provided on the upper surface of the nut 20 have polarities (north and south poles) that attract each other. In this embodiment, the pair of opposing magnets functions as one attraction part 70a and the other attraction part 70b.

[0042] Furthermore, one of the opposing suction portions 70a may be provided so as to protrude from the upper surface of the operating portion 51 or the nut 20, and the other opposing suction portion 70b may be a recess (not shown) into which the suction portion 70a protruding from the upper surface of the operating portion 51 or the nut 20 fits.

[0043] <Anchor installation procedure> The anchor 10 and its installation jigs (driving jig 60, tightening jig 50) of this embodiment are used when attaching a covering member (e.g., a precast panel 90) to a concrete structure (e.g., a bridge pier). The installation procedure for the anchor 10 will be described with reference to Fig. 6. Note that Fig. 6 only shows the state in which the nut 20 is tightened onto the anchor 10 using the tightening jig 50.

[0044] To install the anchor 10, first, an anchor insertion hole 81 is drilled in a concrete structure 80 using a drill or other drilling tool, as shown in Figure 6. The inner diameter and depth of the anchor insertion hole 81 are adjusted to suit the anchor 10 to be installed. Meanwhile, a box hole 91 (counterbored hole) is provided in advance in the covering member (for example, a precast panel 90) so that the head of the anchor body 30 can protrude and the nut 20 can be attached.

[0045] After the anchor insertion hole 81 is formed, the anchor body 30 is inserted into the anchor insertion hole 81 from the fixing portion 40 side, and the tip of the fixing portion 40 is positioned at the back (hole bottom) of the anchor insertion hole 81. Next, the head of the anchor body 30 is fitted into the head insertion hole 62 of the driving jig 60, and the protrusion 63 protruding into the head insertion hole 62 is engaged with the groove 32 provided on the tip surface of the head of the anchor body 30, and the head of the driving jig 60 is struck with a hammer or the like. This causes the sleeve 41 of the fixing portion 40 to expand in diameter, allowing the anchor body 30 to be fixed in the anchor insertion hole 81.

[0046] Furthermore, the nut 20 is screwed onto the head of the anchor body 30 that protrudes into a box cutout 91 (counterbore) provided in a covering member (for example, a precast panel 90). To screw the nut 20 onto the head of the anchor body 30, the operating part 51 of the tightening jig 50 is engaged with the engaging part 21 provided on the top surface of the nut 20, and the tightening body 52 is rotated in the tightening direction.

[0047] At this time, if suction portions 70a, 70b are provided on the upper surfaces of the operating portion 51 and the nut 20, the opposing suction portions 70a, 70b can be attracted to each other. This makes it easy to position the operating portion 51 relative to the engaging portion 21 provided on the upper surface of the nut 20, and also allows the operating portion 51 to be reliably engaged with the engaging portion 21 provided on the upper surface of the nut 20. In this way, a covering member (e.g., a precast panel 90) can be attached to a concrete structure (e.g., a bridge pier).

[0048] <Seismic reinforcement work for concrete support columns> The anchor 10 and anchor installation jig (driving jig 60, tightening jig 50) according to the present invention can be suitably used when carrying out seismic reinforcement work on concrete support columns (bridges for railways, roads, waterways, etc., and other column structures in general, particularly underwater bridge piers, etc.). Seismic reinforcement work on concrete support columns involves installing precast panels 90 containing at least hoop reinforcing bars around the outer periphery of the concrete support column, connecting adjacent precast panels 90 with joints, and filling the gaps between the concrete support column and the precast panels 90 with grout, thereby seismically reinforcing the concrete support column.

[0049] In earthquake-resistant reinforcement work for concrete support columns, the anchor 10 and anchor installation jig (driving jig 60, tightening jig 50) according to the present invention are used when installing precast panels 90 on the outer periphery of the concrete support column. The method for installing the anchor 10 and the method for using the anchor installation jig according to the present invention are as described above.

[0050] When the concrete structure is a concrete support column, the covering member is a precast panel 90, and the precast panel 90 is wrapped around the concrete support column to perform earthquake reinforcement, the tightening torque of the nut 20 onto the head of the anchor body 30 does not need to be strictly specified. This is because the anchor 10 used here is a so-called "expansion prevention" anchor 10, and is a member whose role is to prevent the precast panel 90 from "expansion" in the circumferential direction due to the pressure of the filler, such as mortar, when the outer peripheral surface of the pier and the inner peripheral surface of the precast panel 90 are filled with the filler.

[0051] By using the anchor 10 and anchor installation jig according to the present invention, it is possible to minimize the inner diameter of the box cutout 91 (spot excavation) in the precast panel 90. Furthermore, by minimizing the inner diameter of the box cutout 91 (spot excavation) in the precast panel 90, there are almost no weak points in terms of structure and durability.

[0052] <Application to earthquake-resistant reinforcement work for bridge piers> The case where the concrete support column is a bridge pier installed underwater will be described in more detail with reference to Figure 7. Figures 7(a) to (f) are schematic diagrams showing the procedure for reinforcing a bridge pier 100 installed underwater.

[0053] To carry out repair work on a pier 100 installed underwater, first a temporary pier 110 is installed close to the pier 100. Then, sediment deposited on the footing 120 is removed and the surface of the pier 100 is treated. Furthermore, a hoist crane 130 is installed on the temporary pier 110 to be used for transporting components (a).

[0054] Thereafter, bending reinforcement bars 140 are installed around the pier 100 (b). Once the installation of the bending reinforcement bars 140 is complete, the precast panels 90 to be used for wrapping are assembled on the temporary pier 110. The precast panels 90 are divided into multiple pieces, and are installed with a predetermined gap (the portion filled with grout material) between them and the pier 100 (c).

[0055] Once the precast panels 90 have been assembled to cover the entire periphery of the pier 100, the cylindrical, integrated precast panel 90 is sunk (d). After this, the anchor 10 and anchor installation jig according to the present invention are used to fix the anchor 10 (anchor body 30) to the pier 100, and a nut 20 is tightened onto the head of the anchor body 30 protruding into a box cutout 91 (counterbore) provided in the precast panel 90.

[0056] Once the installation of the precast panel 90 is complete, underwater separable mortar or concrete is filled between the outer circumferential surface of the pier 100 and the inner circumferential surface of the precast panel 90. In addition, filler (epoxy resin putty for the underwater portion) is filled into the box cutout 91 (counterhole) to prevent rusting of the head of the anchor body 30 and the nut 20 (e).

[0057] By repeating the above-mentioned procedure, the precast panels 90 are stacked up to the desired height, completing the reinforcement work (f). The above-mentioned earthquake-resistant reinforcement work for the pier 100 involves wrapping the existing pier 100 with highly durable precast panels 90 manufactured in a factory, which makes it less likely to develop initial defects and provides excellent durability.

[0058] Furthermore, bending reinforcement can also be achieved by placing rebar in the grouted section and fixing it to the footing 120. Furthermore, for piers 100 installed underwater, construction can be carried out without temporary closing or drying up. Furthermore, since part of the seismic reinforcement work for piers 100 installed underwater is carried out underwater by divers, the use of the anchor 10 and anchor installation jig according to the present invention makes the work easier, increases the safety of the work, and improves the construction quality. The improvement in workability and durability in underwater sections is an excellent effect unique to the present invention, which is demonstrated not only in piers but also in all concrete structures that require underwater construction. [Explanation of symbols]

[0059] 10. Anchor 20 nuts 21 Engagement portion 22 Insertion hole 23 Female thread 30 Anchor body 31 Male thread 32 Groove 40 Fixing section 41 Sleeve 42 Tapered bolt 43 Female thread 50 Tightening jig 50a tightening jig (with magnet) 51 Operation section 52 Tightening body 53 Hexagon bolt 54 Bolt mounting holes 55 Control panel 60 Driving jig 61 Driving body 62 recess 63 Protrusion 64 Connection 65 Fitting part 66 Male thread 67 Female thread 68 Holder mounting hole 70a,b Adsorption part 80 Concrete Structures 81 Anchor insertion hole 90 Precast Panels 91 Unboxing 100 Bridge Pier 110 Temporary Pier 120 Footing 130 Hoist Crane 140 Reinforcement

Claims

1. An anchor and its installation jig for driving an anchor into a concrete structure and tightening the anchor into a covering member, comprising an anchor, an anchor driving jig, and an anchor tightening jig, The anchor is a rod-shaped anchor body to be inserted into an anchor insertion hole provided in the concrete structure; a fixing portion that is provided on the distal end side of the anchor main body located in the anchor insertion hole when the anchor main body is inserted into the anchor insertion hole, and that expands in diameter while inserted deep into the anchor insertion hole to press against an inner wall surface of the anchor insertion hole and fix the anchor main body to the deep part of the anchor insertion hole; a nut having a circular cross section and attached to a head side of the anchor body opposite to a side on which the fixing portion is attached, thereby attaching the anchor body to the covering member, The anchor body portion is At least, when the anchor body is inserted into the anchor insertion hole, the anchor body has a male screw portion near the tip end portion to which the fixing portion is attached, the male screw portion has a male screw portion to which the nut is attached near the head portion on the side opposite to the side to which the fixing portion is attached of the anchor body, and further has a groove portion on the head end surface on the side to which the nut is attached, The nut is an insertion hole for inserting a head of the anchor body, a female screw portion provided on an inner surface of the insertion hole, and an engagement portion for engaging the tightening jig on the side opposite to the side where the anchor body is screwed; The driving jig is a rod-shaped driving body portion that is connected to the anchor body portion to extend the anchor body portion and drive the anchor; a head insertion hole provided on a side where the driving body is connected to the anchor body, into which a head of the anchor body is inserted; a protrusion portion that protrudes into the head insertion hole and engages with the groove portion provided on a side of the anchor body that is opposite to a side on which the fixing portion is attached and on which the nut is attached, When driving the anchor, the head of the anchor body is fitted into the head insertion hole, and the protrusion protruding into the head insertion hole is engaged with the groove provided in the head end face of the anchor body on the side where the nut is attached. In this state, the head of the driving jig is struck with a striking member, thereby inserting the anchor into the anchor insertion hole and fixing the fixing portion in the deepest part of the anchor insertion hole. The anchor tightening jig is a rod-shaped fastening body for attaching the nut to a head of the anchor body and fastening the nut to the anchor body; an engagement operation portion provided on the side of the fastening body where the nut is attached, and engaging with an engagement portion provided on the nut on the side opposite to the side where the nut is screwed onto the anchor body, The head of the anchor body is protruded into a box cutout provided in the covering member, and the nut is screwed onto the head of the anchor body protruding into the box cutout. The operating part is engaged with an engaging part provided on the nut on the side opposite to the side where the nut is screwed onto the anchor body, and the tightening body is rotated in the tightening direction, thereby tightening the nut attached to the head of the anchor body. An anchor and its installation jig.

2. The nut has an operating part for the fastening body, and an adsorption part provided on the opposite side of the side where the nut is screwed onto the anchor body, the adsorption parts being opposed to each other and adsorbing to each other, At least one of the opposing attraction portions is a magnet.

2. The anchor and installation jig according to claim 1.

3. A construction method for seismic reinforcement of a concrete support column by installing precast panels containing at least tie bars around the outer periphery of the concrete support column, connecting adjacent precast panels with joints, and filling gaps between the concrete support column and the precast panels with grout, providing an anchor insertion hole in the concrete support column; a step of driving an anchor into the insertion hole using a driving jig and fixing the anchor; a step of attaching a nut to a head of the anchor and tightening the nut using a tightening jig to fix the head of the anchor to the precast panel; and a step of using the anchor to prevent the precast panel from bulging when the grout material is filled into the gap between the concrete support column and the precast panel, The anchor is a rod-shaped anchor body portion to be inserted into the anchor insertion hole provided in the concrete support pillar; a fixing portion that is provided on the distal end side of the anchor main body located in the anchor insertion hole when the anchor main body is inserted into the anchor insertion hole, and that expands in diameter while inserted deep into the anchor insertion hole to press against an inner wall surface of the anchor insertion hole and fix the anchor main body to the deep part of the anchor insertion hole; a nut having a circular cross section and attached to a head side of the anchor body opposite to a side on which the fixing portion is attached, thereby attaching the anchor body to the precast panel; The anchor body portion is at least, when the anchor body is inserted into the anchor insertion hole, the anchor body has a male screw portion near a tip end portion to which the fixing portion is attached, the male screw portion has a male screw portion to which the nut is attached near a head portion on the side opposite to the side to which the fixing portion is attached of the anchor body, and further has a groove portion on an end surface of the head on the side to which the nut is attached, The nut is an insertion hole for inserting a head of the anchor body, a female screw portion provided on an inner surface of the insertion hole, and an engagement portion for engaging a tightening jig on the side opposite to the side where the anchor body is screwed, In the step of driving the anchor into the insertion hole and fixing it in place, a driving jig for driving the anchor into the anchor insertion hole provided in the concrete support pillar is provided, a rod-shaped driving body portion that is connected to the anchor body portion to extend the anchor body portion and drive the anchor; a head insertion hole provided on a side where the driving body is connected to the anchor body, into which a head of the anchor body is inserted; a protrusion portion that protrudes into the head insertion hole and engages with the groove portion provided on a side of the anchor body opposite to a side on which the fixing portion is attached and on which the nut is attached, In the step of driving the anchor into the insertion hole and fixing it, When driving the anchor, the head of the anchor body is fitted into the head insertion hole, and the protrusion protruding into the head insertion hole is engaged with the groove provided in the head end face of the anchor body on the side where the nut is attached. In this state, the head of the driving jig is struck with a striking member, thereby inserting the anchor into the anchor insertion hole and fixing the fixing portion in the deepest part of the anchor insertion hole. A tightening jig for tightening the nut attached to the head of the anchor in the step of fixing the head of the anchor to the precast panel includes: a rod-shaped fastening body for attaching the nut to a head of the anchor body and fastening the nut to the anchor body; an engagement operation portion provided on the side of the fastening body where the nut is attached, the engagement operation portion engaging with an engagement portion provided on the nut on the side opposite to the side where the nut is screwed onto the anchor body, In the step of fixing the head of the anchor to the precast panel, The head of the anchor body is protruded into a box cutout provided in the precast panel, and the nut is screwed onto the head of the anchor body protruding into the box cutout. The operating part is engaged with an engaging part provided on the nut on the side opposite to the side where the nut is screwed onto the anchor body, and the tightening body is rotated in the tightening direction to tighten the nut attached to the head of the anchor body. A method for seismic reinforcement of concrete support columns.

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