JP5695953B2 - Short circuit prevention method in cathodic protection method - Google Patents

Description

  The present invention relates to a method for preventing a short circuit in a cathodic protection method.

  2. Description of the Related Art Conventionally, an anticorrosion construction method is known as a reinforcement corrosion prevention method for a reinforced concrete structure. In this cathodic protection method, a groove is formed on a groove forming surface of a reinforced concrete structure using a concrete cutter or the like, and a long electrode for anticorrosion made of titanium or the like is embedded in the groove. And corrosion of a reinforcing bar can be prevented by energizing both with the embedded electrode for cathodic protection as an anode and a reinforcing bar as a cathode (see Patent Document 1 below).

JP 2010-138686 A

  However, in the anticorrosion for such a reinforced concrete structure, a conductive member such as a binding metal (numbered wire) for binding the reinforcing bar is exposed inside the groove in which the electrode for the anticorrosion is embedded, and this conductive member If a short circuit occurs between the buried electrode for cathodic protection, the anticorrosion effect cannot be obtained as a result.

  In order to prevent such trouble, conventionally, before the electrode for cathodic protection is embedded in the groove, the presence or absence of exposure of the conductive member in the groove has been visually inspected. However, such visual inspection cannot always sufficiently find the conductive member.

  Then, this invention aims at provision of the short circuit prevention method which can detect reliably the exposure of the electroconductive member in the groove | channel formed in the reinforced concrete structure, and can prevent a short circuit reliably.

The method for preventing short circuit in the cathodic protection method of the present invention includes a magnet having a size corresponding to the size of the groove in the groove formed on the groove forming surface of the reinforced concrete structure, along the groove. The magnet is moved, and a short-circuit prevention process is performed on a portion where the magnet attracting force is generated.

According to the above method, when the conductive member is exposed in the groove, when the magnet is moved along the groove with the magnet having a size corresponding to the size of the groove in the groove, Since the magnet is attracted to the exposed conductive member by the magnet's unique magnetic force, the operator can reliably know that the conductive member is exposed at the position where the magnet is attracted, preventing short circuit By knowing the position where the treatment needs to be performed and performing the short circuit prevention process at that position, it is possible to reliably prevent the short circuit between the conductive member and the electrode for cathodic protection embedded in the groove.

In the method for preventing a short circuit in the cathodic protection method of the present invention, a method of applying an insulating treatment as a short circuit preventing process to the portion attracted by the magnet can be employed. By performing an insulation process as a short circuit prevention process, it is possible to reliably prevent a short circuit between the conductive member and the electrode for cathodic protection embedded in the groove.
Further, in the short circuit prevention method in the cathodic protection method of the present invention, the groove forming surface is one of a pair of facing surfaces that are close to each other, and the groove has a pair of facing surfaces facing each other. Is formed so as to extend from one end of the space to the inside of the space, and the magnet is attached to the tip of the rod-shaped body, and the rod-shaped body is operated in a direction along the groove. Thus, it is possible to employ a method of moving the magnet between one end and the other end of the groove.

  According to the short circuit prevention method in the cathodic protection method of the present invention, when the conductive member is exposed in the groove, when the magnet is moved along the groove with the magnet in the groove, the magnet is Because it is attracted to the conductive member by its own magnetic force, the operator can surely know that the conductive member is exposed at the position where the magnet is attracted, and the position where it is necessary to perform a short-circuit prevention treatment Knowing and performing the short circuit prevention treatment at that position, it is possible to reliably prevent a short circuit between the conductive member and the electrode for anticorrosion embedded in the groove.

It is a partially broken side view of the cutting state showing one embodiment of the present invention in use condition. It is a side view of a rail body including the pressing means. It is a rear view of the rail body including the pressing means. It is a top view of the rail body including the pressing means. It is a rear view of the rail space | interval holding | maintenance part. It is a top view of the groove formation part. It is a side view of the groove formation part. It is a rear view of the groove forming part. It is the schematic side view showing the process (state in which the pre-drill was formed in the back surface of a bridge girder) of the groove formation. It is the schematic side view showing the process (state which inserted the rail body in the space) of the groove | channel formation. It is the schematic side view showing the process (state which attached the groove formation part to the rail body) of the groove formation. It is the schematic side view showing the process (state which raised the rail body) of the groove formation. It is a schematic side view showing the process of forming the groove (a state where the groove forming portion is moved forward to form a groove). It is front sectional drawing showing the same anode installation procedure (inspection state of an electroconductive member). It is side surface sectional drawing showing the same anode installation procedure (state which has filled the groove | channel with the 1st mortar). It is side surface sectional drawing showing the same anode installation procedure (state which has pressed the anode against the 1st mortar). It is front sectional drawing showing the same anode installation procedure (state which has pressed the anode against the 1st mortar). It is side surface sectional drawing showing the same anode installation procedure (state which has filled the groove | channel with the 2nd mortar). It is a perspective view of the anode installation part of the same anode installation apparatus. It is a top view of the anode installation part of the same anode installation apparatus. It is a rear view of the anode installation part of the same anode installation apparatus. It is a side view which combines the use condition of the anode installation part of the same anode installation apparatus.

  Hereinafter, the short circuit prevention method in the cathodic protection method according to an embodiment of the present invention will be described. This short-circuit prevention method is carried out for grooves formed on the groove forming surface of a reinforced concrete structure (hereinafter referred to as a concrete structure). After the short circuit prevention method is implemented, a long anode (electrode for anticorrosion) made of a metal such as titanium is embedded in order to prevent corrosion of the reinforcing bars arranged inside the concrete structure.

  First, the cutting device used for forming a groove in a concrete structure will be described. The cutting device is used to form a groove having a predetermined length on a groove forming surface of a concrete structure. The cutting device is inserted in a narrow place and is useful for forming a groove on the groove forming surface in the narrow place.

  A narrow place here is a place where a pair of facing surfaces facing each other cannot enter or is so close to each other that the distance between the facing surfaces is 10 to 40 cm, for example. It is a place like this. One of the opposing surfaces is a groove forming surface that is a target for forming a groove.

  As shown in FIG. 1, the cutting apparatus 1 includes a narrow space between a top end surface 3 of an abutment 2 that is a concrete structure and a back surface 5 of a bridge girder 4 that is a concrete structure facing the top end surface 3 in the vertical direction. A groove 7 having a predetermined width and a predetermined length is formed by using the back surface 5 as one opposing surface as a groove forming surface among the top end surface 3 and the back surface 5 as opposing surfaces that are inserted into a clear space 6. It is a device to do. In this case, the groove 7 is formed of a groove bottom surface and side surfaces that rise from the groove bottom surface and face each other in the lateral direction.

  The formation direction of the groove 7 is a linear direction along the span of the bridge beam 4 as indicated by an arrow 8 in FIG. Therefore, in the groove forming direction, the parapet 9 side of the abutment 2 is defined as the front side, and the opposite abutment (not shown) side as the opposite side is defined as the rear side. Moreover, the left-right direction (groove width direction) is defined toward the front, the right side is one side, and the left side is the other side.

  The cutting device 1 includes a rail body 10 that is used so as to contact the back surface 5, pressing means 11 </ b> A and 11 </ b> B that press the rail body 10 toward the back surface 5 side (upward), and a groove along the rail body 10. And a groove forming portion 12 movable in the forming direction (front-rear direction).

  As shown in FIGS. 2 to 4, the rail body 10 includes a top plate portion 13, a body portion 14, and guide rails 15 </ b> A and 15 </ b> B. In particular, the top plate portion 13 is integrally formed from three top plate components. That is, the top plate portion 13 includes a right top plate portion 16 on one side, a left top plate portion 17 on the other side, and a connecting body 18 that integrally connects and fixes the front end portions of the left and right top plate portions 16 and 17 together. It is configured and is formed in a U shape with a rear portion opened in plan view. With this configuration, the cutting blade protruding space 19 is provided in the central portion in the left-right direction (see particularly FIG. 4).

  The top and bottom plate portions 16 and 17 on both the left and right sides are spaced apart in the left-right direction via the cutting blade protruding space 19. The right top plate portion 16 is set to have a smaller left / right width than the left top plate portion 17 (the left top plate portion 17 is set to have a larger left / right width than the right top plate portion 16).

  With this configuration, the entire cutting blade protruding space 19 is located on one side from the center of the rail body 10 in the left-right direction so that the other end 19a of the cutting blade protrusion space 19 is positioned at the substantially center in the left-right direction of the rail body 10. The position is shifted. The top plate portion 13 has a flat upper surface 20, and the upper surface 20 is a contact portion that contacts the back surface 5 of the bridge girder 4 from below. Specifically, the top plate portions 16 and 17 on both the left and right sides are a pair of contact portions that are spaced apart in the left and right direction via the cutting blade protruding space 19, and each top plate portion 16, The upper surface of 17 contacts the back surface 5 of the bridge girder 4 from below.

  The trunk portion 14 is configured in a frame shape to form a groove forming portion accommodating space for accommodating the groove forming portion 12 below the top plate portion 13, and includes a right top plate portion 16 and a left top plate portion. 17, body skeleton members 21 </ b> A and 21 </ b> B are provided on the lower side of each. Each trunk | skeleton part member 21A, 21B uses the thing of the same structure symmetrically. Each trunk | skeleton part member 21A, 21B is specifically formed in the cross-sectional shape of channel steel.

  In other words, the body skeleton members 21A and 21B are fixed to the bottom plates 22 and 23 parallel to the top plate portion 13 and the back surfaces of the right top plate portion 16 and the left top plate portion 17 parallel to the bottom plates 22 and 23, respectively. The fixed plates 24, 25 and the side plates 26, 27 standing from the ends of the bottom plates 22, 23 so as to integrate the bottom plates 22, 23 and the fixed plates 24, 25 (hanging down from the fixed plates 24, 25). As viewed, it is formed in a U-shaped cross section.

  The body portion 14 includes plate-like reinforcing ribs 28 on the outer sides in the left-right direction of the side plates 26 and 27. The reinforcing ribs 28 are arranged at predetermined intervals in the front-rear direction, and each reinforcing rib 28 is set to a width that does not protrude laterally from the bottom plates 22 and 23 (fixed plates 24 and 25).

  As the trunk skeleton members 21A and 21B are arranged below the right top plate portion 16 and the left top plate portion 17, respectively, the trunk skeleton members 21A and 21B are separated from each other in the left-right direction. (See FIG. 3). The body part 14 has mounting plate members 31 and 32 for attaching rail spacing members 30 (see FIG. 5) on the rear ends of the side plates 26 and 27 of the body frame members 21A and 21B, respectively, on the outer sides in the left-right direction. It is provided integrally so as to protrude. The mounting plate members 31 and 32 are arranged in the middle of the rear ends of the side plates 26 and 27, respectively.

  In addition, the rail interval holding member 30 includes one side portion 30A that is superimposed on the one side mounting plate member 31 from the rear side, the other side portion 30B that is superimposed on the other side mounting plate member 32 from the rear side, the one side portion 30A, and From the intermediate part 30C between the other side parts 30B, it is integrally formed in a plate shape. Further, post-mounting holes 30a and 30b are formed on the plate surfaces of the one side portion 30A and the other side portion 30B so as to match the pre-mounting holes 31a and 32a formed in the mounting plate members 31 and 32, respectively, in the front-rear direction. Has been.

  An intermediate upper portion of the intermediate portion 30C is cut out in the left-right direction, and an insertion cutout 30c for inserting a hook-shaped pressing tool described later is formed. Then, mounting bolts (not shown) are inserted into the rear holes 30a and 30b from the rear and screwed into the mounting front holes 31a and 32a, so that the rail interval holding member 30 is passed to the mounting plate members 31 and 32. Can be installed as.

  The trunk | drum 14 is further provided with cover 33A, 33B in which the cross section was formed in the shape of angle iron (unequal side angle iron). The covers 33A and 33B are formed in an L-shaped cross section that is upside down, and are arranged with the long side portions 34 and 35 on the outside in the left and right direction and the short side portions 36 and 37 on the inside in the left and right direction. In one cover 33 </ b> A, the upper surface of the short side portion 36 is fixed to the back surface of the fixing plate 24. The other cover 33 </ b> B has an upper surface fixed to the rear surface of the left top plate portion 17.

  The guide rails 15 </ b> A and 15 </ b> B are disposed in the groove forming portion receiving space so as to guide the groove forming portion 12 in the groove forming portion receiving space formed by the body portion 14. Specifically, the guide rails 15A and 15B are provided as a pair on the left and right sides, and are fixed to the opposing inner side surfaces (side plates 26 and 27) of the trunk skeleton members 21A and 21B, respectively.

  Each guide rail 15A, 15B has an upper wall 38, 39 along the left-right direction, a lower wall (guide wall) 40, 41 below the upper wall 38, 39 and parallel to the upper wall 38, 39, The walls 38, 39 and the lower walls 40, 41 are formed in a U-shaped cross section from the vertical walls 42, 43 that integrally connect the walls 38, 39. In the present embodiment, the upper surfaces of the lower walls 40 and 41 are guide surfaces 40a and 41a for guiding the groove forming portion 12 in the groove forming direction, with respect to the left and right top plate portions 16 and 17 as contact portions. , And are arranged apart from the top face 3 as the other facing surface. Further, the inner surfaces of the vertical walls 42 and 43 are side guide surfaces 42a and 43a for guiding the first cart 60 in the groove forming direction with both side surfaces 60a and 60a of the first cart 60 described later.

  Next, the pressing means 11A and 11B will be described. One pressing means 11A, 11B is provided on each of the left and right sides of the rail body 10 (provided as a pair of left and right). These pressing means 11A and 11B are jacks (see FIG. 2). More specifically, the pressing means 11A and 11B are pantograph jacks in which link members 55, 56, 57, and 58 are combined.

  The pressing means 11A and 11B are disposed in a region of the trunk skeleton members 21A and 21B where the middle part in the front-rear direction is omitted, and are disposed so as to be displaced forward and backward by the left and right trunk skeleton members 21A and 21B. Yes. Any one of the pair of pressing means 11A and 11B may be front and any may be rear. In the present embodiment, the pressing means 11A on one side is disposed in front of the pressing means 11B on the other side. The upper portions 48 and 49 of the pressing means 11A and 11B are fixed to the left and right outer portions of the back surfaces of the right top plate portion 16 and the left top plate portion 17, respectively. That is, the pressing means 11 </ b> A and 11 </ b> B are contained within the left and right width of the top plate part 13.

  The cutting device 1 includes operation members 52 and 53 for operating the vertical height (extension / contraction) of the pressing means 11A and 11B. The operation members 52 and 53 are screw shaft members and are screwed from the rear to an operation block 54 (only the pressing means 11A on one side in FIG. 2 is shown) which is a nut member provided by the pressing means 11A. . By the rotation of the operation members 52 and 53 around the axis, the pressing means 11A and 11B are expanded and contracted in the vertical direction by changing the connecting angle between the link members 55, 56, 57 and 58. Further, the operation members 52 and 53 are supported by the rail body 10 so that the middle portions in the axial direction pass through the insides of the covers 33A and 33B.

  Next, the groove forming portion 12 will be described with reference to FIGS. The groove forming part 12 includes a first carriage 60, a drive motor part 61 fixed to the first carriage 60, and a cutting blade 62 connected to a drive shaft of a motor (not shown) provided in the drive motor part 61. The support shaft holding member 63 and a duct portion 64 for sucking concrete dust are provided.

  The first carriage 60 is a guided body that is movable along guide surfaces 40a and 41a (see FIGS. 7 and 8) that are upper surfaces of the lower walls 40 and 41 of the guide rails 15A and 15B. As shown in FIG. 6, the first carriage 60 is formed of a rectangular plate member having a longitudinal direction in the front-rear direction when seen in a plan view. Casters (wheels) 65 </ b> A and 65 </ b> B are attached to the four corners of the back surface of the first carriage 60 so as to be rotatable around the left and right lateral wheel shafts. These casters 65A and 65B are placed on the guide surfaces 40a and 41a of the guide rails 15A and 15B, and the first carriage 60 is guided in the front-rear direction.

  As shown in FIG. 7, in a state where the first carriage 60 is moved horizontally, the pair of left and right casters 65A on the front side is rotated by the pair of left and right casters 65B whose rotation center axis (wheel axis) is on the rear side. It is attached to the first carriage 60 via an attachment member (not shown) so as to be positioned below the center axis (wheel axis). Both casters 65A and 65B are set to have the same diameter.

  Side end surfaces (side portions) 60a, 60a on the left and right sides of the first carriage 60 are flat surfaces (smooth surfaces) along the vertical direction. These left and right side end surfaces 60a, 60a are surfaces that can come into contact with inner surfaces (corresponding to side guide surfaces) 42a, 43a of the vertical walls 42, 43 of the guide rails 15A, 15B. In other words, when the first carriage 60 is attached to the rail body 10, the displacement in the left-right direction is regulated loosely by the inner surfaces 42a, 43a of the vertical walls 42, 43.

  As shown in FIG. 6, a cutout portion 66 that is long in the longitudinal direction is formed in a part of the first carriage 60. The first cart 60 includes a pressed member 68 that is used to press it forward. The pressed member 68 is in the center in the left-right direction of the rear end portion of the upper surface 60 b of the first carriage 60, and has a base 69 fixed to the upper surface 60 b of the first carriage 60, and upward from the rear end of the base 69. It is integrally formed from the pressed plate 70 extended toward the surface. A pair of nut members 71 are attached to the pressed plate 70 so as to protrude rearward from each other while being spaced apart in the left-right direction.

  The drive motor unit 61 includes a cylindrical body 72, fixing means 73 for fixing the body 72 to the first carriage 60, a protrusion 74 disposed at the tip of the body 72, and a shaft extending from the protrusion 74. And a member 75. The body 72 has a drive motor (not shown) incorporated therein. The body 72 is inserted into the notch 66 with the drive shaft center 72a of the drive motor extending along the front-rear direction. The fixing means 73 includes a buffer body 76 provided in the front and rear and a mounting belt 77 for buffering vibration caused by driving of the drive motor unit 61.

  The buffer body 76 is made of synthetic rubber, and is attached to the body 72 so as to externally fit the entire body 72 in the circumferential direction (around the drive shaft of the drive motor). The attachment belt 77 is provided for each shock absorber 76 and attaches the body 72 to the first carriage 60 via the shock absorber 76. The attachment belt 77 is firmly fixed to the first carriage 60 with bolts 82 penetrating the plate surface of the first carriage 60. With this configuration, the attachment belt 77 is wound around the shock absorber 76 so as to compress the shock absorber 76 against its elasticity, and the body 72 is held by the first carriage 60.

  The projecting portion 74 is provided at the distal end portion of the body 72 and is disposed so as to project forward from the notch portion 66. The projecting portion 74 includes a bevel gear mechanism (not shown). A rotating shaft 84 (corresponding to a support shaft of the cutting blade 62) connected to the drive shaft via the bevel gear mechanism or the like protrudes horizontally toward the other side. That is, the rotating shaft 84 is cantilevered at the base end side on the body portion 14 side, and the driving force of the driving motor is transmitted from the driving shaft to the rotating shaft 84, whereby the axis along the front-rear direction. The driving force around the center 72a is converted into the driving force around the axis 84a along the left-right direction. A shaft member 75 having a larger diameter than that of the rotating shaft 84 is fitted and fixed to the rotating shaft 84.

  The cutting blade 62 has a thickness corresponding to the width of the groove 7 to be formed. As shown in FIG. 7, the cutting blade 62 has a disk portion 85 and a plurality of cutting edges 62 formed on the outer peripheral portion of the disc portion 85 so as to protrude further radially outward from the outer peripheral portion at predetermined intervals in the circumferential direction. The blade portion 86 is integrally formed. The cutting blade 62 is fitted and fixed with its center of rotation close to the tip of the shaft member 75.

  The rotation shaft 84 as a support shaft that is the rotation center of the cutting blade 62 is arranged to be higher than the wheel shaft that is the rotation center of the front caster 65A. Further, the rotation shaft 84 is arranged in front of the wheel shaft of the front caster 65A, so that at least the outer peripheral upper end of the cutting blade 62 is positioned forward of the caster 65A.

  When the groove forming portion 12 is mounted on the rail body 10, the cutting blade 62 is positioned substantially at the center in the left-right direction of the rail body 10 so that the outer peripheral portion 87 of the cutting blade 62 protrudes upward from the cutting blade protruding space 19. (See FIG. 8). The protruding amount of the cutting blade 62 from the cutting blade protruding space 19 substantially matches the depth of the groove 7 to be formed. And the depth of the groove | channel 7 is the depth which does not contact the reinforcing bar in a concrete structure, and the state which approaches a reinforcing bar as much as possible is preferable.

  The cutting blade 62 has a larger diameter than the thickness (vertical height) of the drive motor unit 61. That is, the upper end portion of the outer peripheral portion 87 of the cutting blade 62 is positioned higher than the upper end portion of the drive motor portion 61, and the lower end portion of the outer peripheral portion 87 of the cutting blade 62 is positioned lower than the casters 65A and 65B. It is set to be.

  As described above, the support shaft holding member 63 is for holding the rotating shaft 84 that is cantilevered. In other words, the support shaft holding member 63 is for holding the rotating shaft 84 that is a support shaft of the cutting blade 62 via the shaft member 75.

  As shown in FIGS. 7 and 8, the support shaft holding member 63 is formed in a single plate shape and is arranged so as to be aligned with the cutting blade 62 in the axial direction of the rotation shaft 84. Specifically, the support shaft holding member 63 is formed in a rectangular shape whose longitudinal direction is the front-rear direction when viewed from the side, the front side as one end side in the longitudinal direction holds the rotating shaft 84, and the other end The rear side as a side is fixed to the first carriage 60.

  The support shaft holding member 63 is dimensioned so that it does not protrude upward with respect to the upper end portion of the outer peripheral portion 87 of the cutting blade 62 and does not protrude downward with respect to the lower end portion of the outer peripheral portion 87 of the cutting blade 62. ing. However, the support shaft holding member 63 is set so as to protrude further forward with respect to the front end portion of the outer peripheral portion 87 of the cutting blade 62. The front end surface 63a of the front end projecting forward is a surface that can contact the connecting body 18 from the rear.

  The duct portion 64 is disposed on the back surface of the first carriage 60, and includes a duct 91 fixed to the back surface at a position immediately behind the cutting blade 62, and a dust suction hose 92 connected to the duct 91. ing. The duct 91 is disposed and fixed on the back surface of the first carriage 60 so that the cutting blade 62 side is open, and the dust suction hose 92 is connected to the rear end portion of the duct 91. A suction device (not shown) is detachably connected to the dust suction hose 92.

  The groove forming part 12 having the above-described configuration has an overall vertical height excluding the cutting blade 62 from the guide surfaces 40a, 41a of the lower walls 40, 41 of the guide rails 15A, 15B to the lower surfaces of the upper walls 38, 39. It is set to be smaller than the height. In other words, the groove forming portion 12 is a groove forming portion formed by the body portion 14 below the top plate portion 13 with the cutting blade 62 protruding upward from the cutting blade protruding space 19 of the top plate portion 13. It is accommodated in the accommodation space and held by the guide rails 15A and 15B.

  Next, a procedure for installing (embedding) the anode 95 on the back surface 5 of the bridge girder 4 using the cutting apparatus 1 having the above-described configuration, that is, a procedure for carrying out the cathodic protection method on the bridge girder 4 will be described. First, a groove forming procedure for forming the groove 7 using the cutting device 1 will be described. In forming the groove, the first carriage 60 and the groove forming part 12 are used in combination.

The outline of the procedure of groove formation is as follows (1) to (8).
(1) On the back surface 5 of the bridge girder 4, marking for clearly indicating a site where the groove 7 is formed is applied.
(2) A pre-excavation (for example, a groove shape having a predetermined length in the front-rear direction) 4a is formed in a portion of the abutment 2 that is rearwardly removed from the top end surface 3 (see FIG. 9). ).
(3) The rail body 10 is inserted into the space 6 between the top end surface 3 of the abutment 2 and the back surface 5 of the bridge beam 4 facing each other (see FIG. 10). Further, the groove forming portion 12 is inserted along the rear end portion side of the rail body 10 (see FIG. 11).
(4) The rail body 10 is moved in the front-rear direction and the left-right direction of the space 6 so that the cutting blade 62 substantially matches the pre-drilling 4a.
(5) The jack is extended to lift the rail body 10, and as shown in FIG. 12, the top surface 20 of the top plate portion 13 as the contact portion of the rail body 10 is brought into pressure contact with the back surface 5 of the bridge girder 4 ).
(6) The drive motor unit 61 is driven to rotate the cutting blade 62, and the groove forming unit 12 is moved forward along the rail body 10 (see FIG. 13).
(7) Further, the groove forming portion 12 is moved forward along the rail body 10.
(8) When the groove forming part 12 is moved to the innermost part (front end part) of the rail body 10 and the length in the front-rear direction of the groove 7 is still required, the jack is shrunk so that the upper surface 20 of the rail body 10 is bridged. 4 is separated from the back surface 5 of the No. 4, and the rail body 10 is further moved forward to carry out (5) to (7).
That's it.

  Next, the steps (1) to (8) will be described in detail in order. First, the step (1) will be described. The position for marking is to know the position of the reinforcing bars embedded in the bridge girder 4 in advance, to the required position based on the arrangement of the reinforcing bars to be subjected to the cathodic protection method, at predetermined intervals in the lateral direction (width direction) of the bridge girder 4 It is preferable to apply.

  Next, the step (2) will be described. The pre-drilling 4a is formed by the concrete cutter etc. in the said marking position. In FIG. 10, a support member such as a hinge that supports the bridge girder 4 with respect to the top end surface 3 of the abutment 2 is omitted. As this preliminary excavation 4a, for example, a groove having a predetermined length formed in the front-rear direction so that the front end portion is continuous with the marking can be considered.

  The pre-dig 4a is preferably formed in advance in the lateral direction on the back surface 5 of the bridge girder 4 (girder end) in accordance with the number of grooves 7 to be formed. Moreover, as a formation area of the pre-drill 4a, from the site | part which remove | deviated from the site | part (site which forms the space space 6) which opposes the top end surface 3 of the abutment 2 of the back surface 5 of the bridge girder 4 of the space space 6 It is preferable to extend the rear end (about the rear entrance). The reason for forming the pre-dig 4a is to secure the biting of the cutting blade 62 with respect to the back surface 5 (an opportunity to start cutting).

  The process (3) will be described. The operator inserts the rail body 10 from the rear to the front at a desired position in the space 6 so that the top plate 13 is on the upper side and the guide rails 15A and 15B are on the lower side (see FIG. 10). At this time, if the jack is contracted, the height of the cutting device 1 as a whole is low. Therefore, even if the space space 6 is narrow, the rail body 10 can be easily inserted into the space space 6. it can.

  When the rail body 10 is inserted into the space 6, the lower portions 50 and 51 of the jack are placed on the top end surface 3 of the abutment 2. At this time, the rail body 10 is not inserted into the space 6 in all the regions in the front-rear direction, and the rear end portion of the rail body 10 protrudes rearward from the space 6.

  Subsequently, the operator places the groove forming portion 12 in the rear of the rail body 10 so that the casters 65A and 65B are placed on the guide surfaces 40a and 41a of the lower walls 40 and 41 of the guide rails 15A and 15B. (That is, the groove forming part 12 is accommodated in the groove forming part accommodating space of the rail body 10 from the rear) (see FIG. 11). At this time, the rail body 10 is not inserted into the space space 6 in all the regions in the front-rear direction, and the rear end portion of the rail body 10 protrudes rearward from the space space 6. The groove forming portion 12 can be easily attached.

  When the groove forming portion 12 is inserted into the rail body 10 as described above, the portion of the outer peripheral portion 87 of the cutting blade 62 located on the upper side is separated from the cutting blade protruding space 19 by the top of the rail body 10. It will be in the state which protruded upwards with respect to the upper surface 20 of the board part 13. FIG. Further, the side end surfaces 60a, 60a of the first carriage 60 face the inner surfaces 42a, 43a of the vertical walls 42, 43 of the guide rails 15A, 15B slightly spaced apart so as to be loosely fitted.

  When the insertion of the groove forming portion 12 into the rail body 10 is completed, the rail interval holding member 30 is attached to the groove forming portion 12. In this case, as described above, mounting rails are inserted into the rear holes 30a and 30b from the rear and screwed into the mounting front holes 31a and 32a, so that the rail interval holding member 30 is attached to the mounting plate members 31 and 32. Can be installed to deliver.

  The process (4) will be described. The operator can move the rail body 10 in the front-rear direction and the left-right direction in the space 6 so that the cutting blade 62 of the groove forming portion 12 inserted into the rail body 10 substantially matches the preliminary excavation 4a formed in the step (2). Move with the direction position in mind. When this positioning is completed, the process proceeds to step (5).

  In the step (5), the operation members 52 and 53 of the jack as the pressing means are rotated using an operation tool (not shown) such as an electric tool. Then, since the lower portions 50 and 51 of the jack are placed on the top end surface 3 of the abutment 2, the jack extends upward, and the groove forming portion 12 is mounted by the lifting force (pushing force). The rail body 10 itself rises toward the back surface 5 of the bridge girder 4 (see FIG. 12).

  That is, due to the extension of the jack, the rail body 10 moves to the back surface 5 side of the bridge girder 4, and the groove forming portion 12 held by the rail body 10 also moves to the back surface 5 side of the bridge girder 4 with this movement. When the rail body 10 approaches the back surface 5 side of the bridge girder 4 and finally the upper surface 20 of the top plate portion 13 comes into pressure contact with the back surface 5 of the bridge girder 4, a narrow space (space space) of the rail body 10 is obtained. 6) The placement in is completed. The height position at which the rail body 10 is fully raised is specified as the position at which the upper surface 20 of the top plate portion 13 of the rail body 10 is pressed against the back surface 5 of the bridge girder 4. And the outer peripheral part 87 which protruded upwards from the cutting blade protrusion space 19 of the cutting blade 62 enters the pre-dig 4a and is pressed against it.

  The process (6) will be described. When the operator electrically drives the drive motor unit 61, the driving force of the drive motor is transmitted to the rotary shaft 84 via the drive shaft, and the cutting blade 62 and the rotary shaft 84 have an axial center 84 a along the left-right direction. Rotate around. In this case, the cutting blade 62 rotates clockwise in FIG. Then, the rail body 10 is moved forward along the groove forming portion 12. And the said hook-shaped pressing tool etc. are prepared and the groove | channel formation part 12 is pressed ahead using this. Alternatively, it may be pushed electrically by using a separate drive mechanism.

  In this embodiment, the first carriage 60 includes a pressed member 68, and the pressed plate 70 includes a pair of nut members 71 spaced apart in the left-right direction, so that the groove forming portion 12 is pressed. For this purpose, it is preferable that the nut member 71 is pressed by attaching the tip of the pressing tool. The pressing tool is inserted into the insertion notch 30c of the rail interval holding member 30 from behind. And the formation of the groove | channel 7 starts by pressing the groove | channel formation part 12 ahead with a pressing tool.

  By the way, as described above, in the state where the first carriage 60 of the groove forming portion 12 is moved horizontally, the rotation center axis of the pair of left and right casters 65A on the front side is the rotation center of the pair of left and right casters 65B on the rear side. The casters 65A and 65B are positioned below the shaft and have the same diameter. According to this configuration, when the groove forming portion 12 is inserted into the rail body 10 from the rear and both the front and rear casters 65A and 65B are placed on the guide surfaces 40a and 41a, the first carriage 60 is caster 65A and 65B. The front portion is inclined upward (the rear portion is inclined downward) by the height difference. When the operator presses the groove forming portion 12 forward, the rear caster 65B presses so as not to separate from the guide surfaces 40a and 41b, so that the cutting blade 62 moves upward with the front caster 65A as a fulcrum. The state of being pushed by (the back surface 5 side of the bridge girder 4) is maintained. By pressing the first carriage 60 while maintaining this state, the depth of the groove 7 can be secured constant.

  In addition, the force which presses the groove | channel formation part 12 ahead needs to resist the hardness of concrete so that the cutting blade 62 can cut the surface part of concrete by the rotation. When the formation of the groove 7 is started, if it is easier to work without mounting the rail interval holding member 30, the rail forming portion 12 is pushed by the operator's own hand without mounting the rail interval holding member 30. It is also possible to make it. The rail spacing member 30 can be used even after the groove 7 is formed to a certain length.

  The step (7) will be described. Furthermore, the groove | channel 7 along the front-back direction is formed in the back surface 5 by moving the groove formation part 12 along the rail body 10 ahead. The groove forming portion 12 can be moved until the front end face 63a of the support shaft holding member 63 contacts the connecting body 18 (see FIG. 13). Further, since the groove forming portion 12 does not move further forward when the front end surface 63a of the support shaft holding member 63 abuts on the connecting body 18, the cutting blade 62 does not hit the connecting body 18, and therefore the cutting blade 62 Can be prevented from being damaged. Further, the front end face 63a of the support shaft holding member 63 abuts on the connecting body 18, thereby avoiding a situation in which the groove forming portion 12 is unexpectedly detached from the front end portion of the rail body 10, and ensuring safety. be able to.

  By the way, as described above, the force that presses the groove forming portion 12 forward needs to resist the hardness of the concrete so that the cutting blade 62 can cut the surface portion of the concrete by its rotation. Therefore, a load (external force) corresponding to the cutting of concrete acts on the cutting blade 62. Since the rotary shaft 84 is cantilevered, the external force becomes a large moment around the fulcrum (around the axis of the drive shaft), vibrations associated with concrete cutting, etc. There is a risk of blurring.

  However, since the rotation shaft 84 as a support shaft of the cutting blade 62 is held by the support shaft holding member 63 fixed to the first carriage 60, the external force as described above is applied to the rotation shaft 84 via the cutting blade 62. Even if it works, the rotation behavior of the cutting blade 62 can be stabilized by suppressing the shake of the rotating shaft 84. Therefore, it is possible to ensure the forming accuracy of the groove 7 formed from the side surface facing the groove bottom surface corresponding to the cross-sectional shape of the outer peripheral portion 87 of the cutting blade 62.

  Further, the side end surfaces 60a, 60a on both the left and right sides of the first carriage 60 are surfaces that can come into contact with the inner surfaces 42a, 43a of the vertical walls 42, 43 of the guide rails 15A, 15B, and the vertical walls 42 of the guide rails 15A, 15B. , 43 are surfaces which can loosely restrict the displacement of the first carriage 60 in the left-right direction. For this reason, the inner surfaces 42a and 43a serve as side guide surfaces in the forward movement along the guide rails 15A and 15B of the first carriage 60, so that both end portions of the first carriage 60 are forward (groove forming direction). It can guide smoothly towards. Accordingly, in the rail body 10, the first carriage 60 can be guided in a state where the first carriage 60 is reliably aligned in the front-rear direction, so the groove 7 can also be formed linearly along the front-rear direction, and the molding accuracy of the groove 7 can be increased. Can be secured.

  In addition, there is a connecting body 18 at the front end portion of the rail body 10, and the position is reliably held so that the positional relationship between the guide rails 15A and 15B is not displaced. However, the rear end portions of the guide rails 15A and 15B are For the convenience of inserting the groove forming portion 12, a member having a function such as the connecting body 18 cannot be provided in advance. For this reason, after inserting the groove forming part 12 into the rail body 10, the rail spacing holding member 30 shown in FIG. 15B, even if an external force that separates the rear end portions of the guide rails 15A and 15B in the left-right direction is applied, the separation distance between the rear end portions of the guide rails 15A and 15B due to the holding force of the rail interval holding member 30 Can be held.

  As described above, the guide surfaces 40a and 41a of the guide rails 15A and 15B have the front end side held by the connecting body 18 and the rear end side held by the rail interval holding member 30, so that the separation distance in the lateral direction as a whole is increased. Can be prevented from changing unexpectedly. Therefore, the groove forming portion 12 can be moved without being displaced in the left-right direction, and the groove forming accuracy can be ensured.

  By the way, a concrete structure is generally blended with a material for securing strength having a different particle size called aggregate. Depending on the particle size of the aggregate, when the cutting blade 62 rotates and moves forward, a large load may be applied to the cutting blade 62. However, with respect to the rotation center axis (wheel axis) of the pair of left and right casters 65A on the front side, the first carriage 60 is arranged such that the rotation center axis (wheel axis) of the pair of left and right casters 65B on the rear side is located above. Installed on. For this reason, when the groove forming portion 12 is mounted on the rail body 10 so that the casters 65A and 65B are placed on the guide surfaces 40a and 41a, the rear side is formed between the lower surface of the upper walls 38 and 39 and the groove forming portion 12. A wider clearance is generated.

  For this reason, when a large load is applied to the cutting blade 62 by the aggregate, the rear part (the rear casters 65B and 65B) of the first carriage 60 mainly moves upward so as to be lifted from the guide surfaces 40a and 41a. Absorbs the load on the blade 62. Therefore, it is possible to suppress blurring, breakage, and damage during rotation of the cutting blade 62 due to an excessive load on the cutting blade 62, thereby ensuring the forming accuracy of the groove 7 (the shape of the groove 7). The durability of the cutting blade 62 can be improved.

  The step (8) will be described. When the groove forming part 12 is moved to the innermost part (front end part) of the rail body 10 and the length of the groove 7 in the front-rear direction is required, the jack is once shrunk and the upper surface 20 of the rail body 10 is Separated from the back surface 5. If it does so, since the pressing force of the jack which has positioned the rail body 10 will be cancelled | released, there will be nothing which prevents the movement of the rail body 10 in the front-back direction. Therefore, the rail body 10 can be easily moved further to the back side (front), and the operator can form the longer groove 7 by performing the steps (5) to (7) again. it can.

  When the formation of one groove 7 is completed, the cutting device 1 (rail body 10) is moved laterally leftward or rightward along the back surface 5 so that the cutting blade 62 coincides with the next marking position. The required number of grooves 7 are sequentially formed by moving and repeating the operations (3) to (8) or (5) to (8). That is, the cutting device 1 is moved with the amount of movement of the cutting device 1 in the lateral direction substantially equal to the groove forming interval, and the grooves 7 are formed sequentially. The above is the process for forming the groove.

  The cutting device 1 is configured such that only the outer peripheral portion 87 of the cutting blade 62 of the groove forming portion 12 is exposed from the rail body 10 and the other portion is accommodated in the rail body 10 (groove forming portion accommodating space). Therefore, it is possible to suppress the height of the entire cutting apparatus 1 from being increased by that much, and it can be used extremely effectively even in a narrow space with a low height.

  Therefore, in a narrow space where an operator cannot enter, such as a space 6 formed by the top end surface 3 of the abutment 2 and the back surface 5 of the bridge girder 4, the reinforcing bars arranged inside the concrete structure In order to prevent corrosion, the groove 7 in which the anode 95 is embedded is formed on the back surface 5. For example, the shape of the space space 6 can be obtained without requiring the work to hang the top end surface 3 of the abutment 2 to secure the work space. The groove 7 can be formed while maintaining In this way, since the operator can omit the hanging work (work for widening the space 6), the construction of the groove formation becomes extremely easy.

  When the formation of the groove 7 is completed, the process proceeds to the step of burying the anode 95 in the groove 7. In the process of embedding the anode 95, first, it is necessary to know the metal exposure such as the binding metal of the reinforcing bar in the groove 7 formed. This is because, if the conductive member is exposed in the groove 7 and the conductive member comes into contact with the anode 95 to be buried later, a short circuit occurs between the conductive member and the anode 95, and the effect of the anticorrosion is obtained. This is to prevent an event that it cannot be obtained.

  Therefore, as shown in FIG. 14, the magnet G is put into the groove 7 that has been formed, and is moved along the groove 7. The magnet G is preferably used by being attached to the distal end portion of the bowl-shaped material S having a length that can sufficiently reach the innermost portion of the groove 7. And if the magnet G is moved and the attraction | suction force by the magnetic force of the magnet G arises, since there will be exposure of an electroconductive member there, a short circuit prevention process will be given to the area | region. In this way, by examining the presence or absence of exposure of the conductive member into the groove 7 using the magnet G, it is possible to surely know whether or not the conductive member is exposed into the groove 7 and to perform a short-circuit prevention treatment. it can. As the short-circuit prevention treatment, a metal removal treatment for removing the exposed portion of the metal and an insulation treatment for applying an insulating material so as to cover the exposed metal can be considered.

  As described above, after performing the short-circuit prevention treatment as necessary, as shown in FIG. 15, the groove 7 is filled with the first mortar (grouting material) 115 to a predetermined thickness. The first mortar 115 is a mixture of fine aggregate and water only in cement. At the time of filling, the mortar injection tool M that can accommodate a certain amount of the first mortar 115 is filled over the entire length direction of the groove 7 to the back of the groove 7 (groove bottom surface). Then, the anode 95 is inserted into the groove 7 before the first mortar 115 is cured.

  Here, as shown in FIGS. 16 and 17, the anode 95 is formed of a long band-shaped metal body having a mesh, and the metal body is bent at the center in the width direction (short direction). The width of the anode 95 in the bent state is set larger than the width of the groove 7. The mesh has a rhombus shape formed during stretching when the anode 95 is processed into an expanded metal shape.

  In order to attach the anode 95 to the groove 7 filled with the first mortar 115, the groove forming part 12 (in the figure, the cutting blade 62 is removed and replaced with the electrode pressing body 99 shown in the figure in the groove forming part 12 described above. , Only the electrode pressing body 99 is described). The electrode pressing body 99 is formed in a disk shape with a center hole 99a formed at the center of rotation. The outer peripheral portion 106 of the electrode pressing body 99 is formed by an inclined surface in which both sides in the thickness direction are inclined toward the center in the thickness direction so that the center portion of the blade thickness is radially outward (maximum diameter). It is the outer peripheral tip. The diameter of the electrode pressing body 99 is set slightly smaller than that of the cutting blade 62.

  With the anode 95 inserted into the groove 7 in a certain length from the rear to the front with the bent portion facing upward, the operations shown in the above (3) to (5) are performed. Then, the operation shown in (7) is performed. Then, the outer peripheral tip of the electrode pressing body 99 is inserted into the bent portion of the anode 95, and the anode 95 is sequentially pressed upward (in the groove bottom side) in the longitudinal direction. Since the first mortar 115 contains only fine aggregate, the first mortar 115 enters between the rhombic meshes of the anode 95, and the anode 95 holds the holding power of the first mortar 115 and the side of the anode 95 itself. The anode 95 can be held without dropping from the groove 7 due to the elastic force in the direction.

  Thus, in order to mount the anode 95 in the groove 7, the cutting blade 62 of the groove forming portion 12 is removed and replaced with the electrode pressing body 99, and this is moved along the rail body 10 to push in the cutting device 1. By using it as a tool, the electrode pressing body 99 can be reliably pushed into the groove 7 by the lifting force of the jack. Then, if the cutting blade 62 is removed and replaced with the electrode pressing body 99 and the electrode pressing body 99 is pushed into the groove 7 by the pushing-up force of the jack, the rail body 10 is attached to mount the electrode pressing body 99 in the groove 7. Is not required to be removed from the space 6. Moreover, since the cutting device 1 can also be used as a means for pushing up the electrode pressing body 99, the work efficiency for mounting the anode 95 is good, and a special device is prepared for pushing up the electrode pressing body 99. It is not necessary.

  The anode installation operation as described above is performed for each groove 7, and subsequently, as shown in FIG. 18, the second mortar 116 is placed in the space of the groove 7 that is not filled, similarly to the filling of the first mortar 115. And fill. The second mortar 116 may be a mortar using a coarser aggregate than the aggregate blended in the first mortar 115 or the same mortar as the first mortar 115. In this way, the anode 95 can be reliably installed in the groove 7.

  As the anode installation work, all the grooves 7 are formed in advance, and the filling of the first mortar 115, the installation of the anode 95, and the filling of the second mortar 116 are sequentially performed on each groove 7. May be filled with the first mortar 115, the anode 95 may be installed, and the second mortar 116 may be filled. 7 may be sequentially installed, and then the second mortar 116 may be sequentially filled in all the grooves 7. The selection of the procedure can be arbitrarily selected according to the work environment.

  In any case, the rail body 10 is moved along the back surface 5 to the left or right, which is the lateral direction, and is arranged along the next groove 7. The anode 95 is sequentially installed in all the grooves 7 by repeating the anode installation operation of moving the electrode pressing body 99 and pushing the anode 95 into the next groove 7. That is, the anode 95 can be installed in the grooves 7 in order by setting the amount of movement of the rail body 10 in the lateral direction to be substantially equal to the distance between the grooves, so that the anode can be installed efficiently.

  In addition, after the groove 7 is formed using the cutting device 1, an electrode installation device that is a unique device may be used to attach the anode 95 to the groove 7. Here, based on FIGS. 19-22, the electrode installation apparatus 96 for installing the anode 95 in the groove | channel 7 is demonstrated. The electrode installation device 96 includes the rail body 10 already described and an electrode installation portion 97 that can move in the front-rear direction along the rail body 10. Since the structure of the rail body 10 is as described above, the description thereof will be omitted, and the electrode installation portion 97 will be described below.

  The illustrated electrode installation portion 97 includes a carriage (hereinafter referred to as “second carriage”) 98 and an electrode pressing body 99. The second carriage 98 is guided along the rail body 10 in the groove forming direction. Specifically, the second carriage 98 is guided for electrode installation that can move in the front-rear direction along the guide surfaces 40a and 41a of the guide rails 15A and 15B. The left and right widths of the body are set equal to those of the first carriage 60. The second carriage 98 is formed between a pair of left and right caster (wheel) attachment region 101 to which the caster 100 (wheel) is attached, and the caster (wheel) attachment region 101, and the electrode pressing body 99 is installed. It is formed from a plate member having a region portion 102. The plate member constituting the second carriage 98 is formed in a shape in which unnecessary portions are omitted in consideration of weight balance at the left and right side portions with respect to the center in the left-right direction and weight reduction. In particular, a specific region 105 between the electrode support wall 103 and the pressing wall 104 described later is cut away.

  The electrode support wall 103 is erected at the front end (front end) of the second carriage 98. The electrode support wall 103 is formed so as to rise upward at the front end portion of the front projecting portion of the installation region portion 102, and an insertion hole 103a for allowing the anode 95 to pass in the front-rear direction is formed at the center in the left-right direction. ing. In addition, the electrode support wall 103 is set to a width that is considerably smaller than the left and right width of the second carriage 98, and is disposed so as to be shifted to the other side with respect to the left and right width center of the second carriage 98. Therefore, the insertion hole 103a is also displaced from the center of the left and right width of the second carriage 98 on the other side. The amount of positional deviation of the insertion hole 103a from the center in the left-right direction of the second carriage 98 is equal to the amount of positional deviation of the cutting blade 62 in the cutting device 1.

  At the rear end portion of the second carriage 98, the pressing wall 104 for pressing the second carriage 98 from the rear to the front is provided upright. The pressing wall 104 is set to have the same width as the left and right width of the second carriage 98, and the vertical height is set lower than the vertical height of the installation region portion 102. Further, the pressing wall 104 is formed with an attachment hole 104a for attaching a distal end portion of a pressing rod member (not shown). The position of the mounting hole 104a in the left-right direction is shifted to the other side with respect to the center of the left-right width of the second carriage 98, and the amount of position shift is the amount of position shift of the insertion hole 103a in the installation region portion 102. Is the same. Therefore, the mounting hole 104a and the insertion hole 103a are in the same position in the left-right direction. However, the mounting hole 104a is formed at a lower position in the vertical direction than the insertion hole 103a.

  The electrode pressing body 99 has the same configuration as that described with reference to FIGS. 16 and 17. That is, with reference to these drawings, the electrode pressing body 99 is formed in a disk shape in which a central hole 99a is formed at the center of rotation. An internal thread is formed on the peripheral surface of the center hole 99a. The outer peripheral portion 106 of the electrode pressing body 99 is formed by an inclined surface in which both sides in the thickness direction are inclined toward the center in the thickness direction so that the center portion of the blade thickness is the outermost in the radial direction (maximum diameter). It is the outer peripheral tip.

  As shown in FIGS. 21 and 22, the electrode pressing body 99 is disposed between the electrode support wall 103 and the pressing wall 104, and a substantially lower half thereof is a notch between the electrode support wall 103 and the pressing wall 104. It is attached to the second carriage 98 via the support means 107 so as to protrude downward from the specified area 105. The electrode pressing body 99 is supported by the support means 107 at a position displaced from the center in the left-right direction of the second carriage 98 so that the center in the thickness direction coincides with the position in the left-right direction of the insertion hole 103a. . The height position of the upper end portion of the electrode pressing body 99 is set to be higher than the insertion hole 103a.

  The support means 107 includes a support piece 108 erected on the upper surface of the second carriage 98 so as to be flush with the end face of the specific region 105 notched between the electrode support wall 103 and the pressing wall 104, and the support piece 108. Is formed of a support shaft body 109 penetrating in the left-right direction and a bush 110 that externally fits one end portion of the support shaft body 109.

  The shaft body 109 has an axial center extending in the left-right direction, a male screw 109a is formed on the other side, and is secured from the support piece 108 by a snap ring 112. The electrode pressing body 99 is attached to the support shaft body 109 by the center hole 99a being screwed into the male screw. An annular buffer member 113 is interposed between the electrode pressing body 99 and the support piece 108.

  The casters (wheels) 100 protrude downward from the back surface of the second carriage 98, are provided in the left and right caster (wheel) attachment region portions 101, and are arranged in pairs in the left-right direction. These casters 100 are disposed on the back surface of the second carriage at the same position in the front-rear direction.

  The electrode installation portion 97 having such a configuration is used by being mounted on the rail body 10. The electrode installation portion 97 is a groove forming portion accommodation space formed by the body portion 14 below the top plate portion 13 in a state where the electrode pressing body 99 protrudes upward from the cutting blade protruding space 19 of the top plate portion 13. (In this case, it is accommodated in the electrode installation portion accommodating space) and is held by the guide rails 15A and 15B. Specifically, the electrode installation portion 97 is mounted by inserting the caster 100 between the guide rails 15A and 15B so that the caster 100 is placed on the guide surfaces 40a and 41a of the guide rails 15A and 15B.

  When the anode 95 is installed in the groove 7 using the electrode installation portion 97, the groove 7 has already been formed. Therefore, the rail body 10 is inserted into the space 6 in advance and the top end surface 3 of the abutment 2 and the bridge girder 4 You may install in general between the back surfaces 5. However, since it is necessary to align the electrode pressing body 99 of the electrode installation portion 97 with the groove 7, fine adjustment in the left-right direction of the rail body 10 after the electrode installation portion 97 is mounted on the rail body 10 is appropriately performed. is necessary.

  When the electrode installation portion 97 is attached to the rail body 10, as shown in FIG. 22, the anode 95 is inserted through the insertion hole 103a of the electrode support wall 103 from the front to the rear in advance, The upper end of the body 99 is retracted (introduced). The anode 95 is held so that the outer peripheral tip of the electrode pressing body 99 is inserted into the bent portion. Then, when the electrode pressing body 99 is aligned with the groove 7 and the jack is extended so that the upper surface 20 of the top plate portion 13 is pressed against the back surface 5 of the bridge girder 4, the upper end of the electrode pressing body 99 is extended (pushing up). Enters the groove 7, and the rear end of the anode 95 at the upper end of the electrode pressing body 99 is pushed into the starting point of the mounting of the anode 95 in the groove 7. Push forward along 10.

  At this time, the operator may directly press the electrode installation part 97, but the electrode installation part 97 is attached by attaching the tip of the pressing rod member to the mounting hole 104a of the pressing wall 104 and pressing the pressing rod member. Can be pushed in easily. As the electrode installation portion 97 is pushed in, the anode 95 is pressed to the back side (first mortar 115) of the groove 7, and is held (held) between the first mortar 115 and the outer peripheral tip of the electrode pressing body 99. Thus, the electrode pressing body 99 is rotated around the support shaft body 109 by the clamping force, and the anode 95 is sequentially drawn from the insertion hole 103 a as the support shaft body 109 rotates, and the anode 95 is sequentially mounted in the groove 7. .

  When the mounting of the anode 95 for one groove 7 is completed, the rail body 10 is moved so as to align the electrode pressing body 99 with the next groove 7 filled with the first mortar 115 in advance. Through the above operation, the anode 95 is installed for each groove 7. Then, after the installation of the anode 95 in the groove 7 is completed, the second mortar 116 is filled in the groove 7 and the electrode installation work is completed.

  In the operation of using the rail body 10 and installing the anode 95 in the groove 7 using the electrode installation portion 97, it is not necessary for the operator to install the anode 95 by inserting an arm into the narrow portion in the narrow portion. 95 can be installed very easily and efficiently.

  Thus, the electrode installation part 97 is movable in the groove 7 along the second carriage 98, and the second carriage in a state of being rotatable about the axis along the back surface 5 that is perpendicular to the groove forming direction and is the groove forming surface. A disk-shaped electrode pressing body 99 attached to 98 and an electrode support wall 103 as a guide portion for introducing and guiding the anode 95 to the outer peripheral portion of the electrode pressing body 99 are provided. Then, by moving the second carriage 98 in the groove forming direction, the outer peripheral portion of the electrode pressing body 99 moves the anode 95 aligned with the groove 7 as the second carriage 98 moves in the groove forming direction. The anode 95 can be installed in the groove 7 while pressing toward the groove bottom side.

  In the above embodiment, the groove 7 for installing the anode 95 is formed in the back surface 5 of the bridge girder 4 in the narrow space 6 formed by the relationship between the top end surface 3 of the abutment 2 and the back surface 5 of the bridge girder 4. Explained. However, in addition to the abutment 2, the groove 7 is formed on the back surface 5 of the bridge girder 4 in the narrow space 6 formed by the relationship between the top end surface of the pier supporting the bridge girder 4 and the back surface 5 of the bridge girder 4. Even if it exists, the cutting device 1 can be used similarly to the said embodiment. In this case, as long as the setting in the front-rear direction is along the axial center of the bridge girder 4, any girder end of both girder ends may be the front. In addition to the abutment 2, the electrode installation device 96 also has a groove formed in the back surface 5 of the bridge girder 4 in a narrow space 6 formed by the relationship between the top end surface of the pier on which the bridge girder 4 is supported and the back surface 5 of the bridge girder 4. 7 can be used in the same manner as in the above embodiment.

  In the said embodiment, it demonstrated by the case where the groove | channel 7 was formed in the back surface 5 of the bridge girder 4. FIG. However, the cutting device 1 can also form the grooves 7 in the top end surface 3 of the abutment 2 in a narrow space 6. In this case, the rail body 10 and the groove forming portion 12 are used so as to be reversed upside down, and the lower portions 50 and 51 of the pressing means 11A and 11B are pressed against the back surface 5 of the bridge girder 4 to 20 is pressed against the top end surface 3 of the abutment 2, and the rail body 10 is mounted in the space 6. The electrode installation device 96 also uses the rail body 10 and the electrode installation portion 97 so as to be turned upside down, so that the anode 95 is installed in the groove 7 formed in the top end surface 3 of the abutment 2 in the narrow space 6. Can do.

  In addition, in the said embodiment, it demonstrated by the case where both of a pair of opposing surfaces which oppose are the surfaces of a concrete structure. However, if one surface forming the groove 7 is the surface of a concrete structure, the other surface may be the surface of a concrete structure, such as a wood structure or a stone structure.

  DESCRIPTION OF SYMBOLS 1 ... Cutting device, 2 ... Abutment, 3 ... Top end surface, 4 ... Bridge girder, 4a ... Pre-drilling, 5 ... Back surface, 6 ... Spatial space, 7 ... Groove, 10 ... Rail body, 11A, 11B ... Pressing means, 12 ... Groove forming part, 13 ... Top plate part, 15A, 15B ... Guide rail, 19 ... Space for cutting blade protrusion, 31, 32 ... Plate member, 40a, 41a ... Guide surface, 60 ... First carriage, 60a, 60a ... side End face, 60c ... Front face, 61 ... Drive motor part, 62 ... Cutting blade, 63a ... Front end face, 65A, 65B ... Casters, 66 ... Notch part, 72a ... Drive shaft, 73 ... Fixing means, 74 ... Projection part, 75 ... Shaft member, 76 ... Buffer, 84 ... Rotating shaft, 95 ... Anode, 97 ... Electrode installation part, 98 ... Second carriage, 99 ... Electrode pressing body, 103 ... Electrode support wall, 103a ... Insertion hole, 115 ... First 1 mortar, 116 ... second mortar

Claims (3)

With the magnet having a size corresponding to the size of the groove placed in the groove formed on the groove forming surface of the reinforced concrete structure, the magnet is moved along the groove, and the attraction force of the magnet is increased. A method for preventing a short circuit in the cathodic protection method, wherein a short circuit preventing process is performed on the generated portion.   2. The method for preventing a short circuit in the cathodic protection method according to claim 1, wherein an insulating process is performed as a short circuit preventing process on the portion to which the magnet is attracted. The groove forming surface is one opposing surface of a pair of opposing surfaces that are close to each other.
The groove is formed so as to reach the inside of the space space from one side end portion in the space space where a pair of opposed surfaces are opposed to each other.
The magnet is attached to the tip of the bowl;
3. The short circuit prevention in the cathodic protection method according to claim 1, wherein the magnet is moved between one end and the other end of the groove by manipulating the bowl in a direction along the groove. Method.

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