JP2012002003A - Handrail post erection method and post erection hole forming mold used for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a handrail post erection method capable of facilitating formation of a post erection hole and improving construction efficiency.SOLUTION: A post erection hole forming mold 1 is composed of a cylindrical bottomed inner tube 2 with clearance forming projection leveled parts 5 protrusively provided on both sides of outer peripheral surface of the inner tube 2 and an outer tube 4 consisting of a pair of half-split bodies 3, 3 fitted over the inner tube 2 so that the opposed end faces 3o, 3o of both of the half-split bodies 3, 3 abut on the respective both side end faces 5o, 5o of the projection leveled parts 5. After the post erection hole forming mold 1 is suspended in a sheathing wall form 13, concrete 20 is placed in the form 13. After the concrete is solidified, the inner tube 2 of the mold 1 is pulled out from the outer tube 4 and then impact is applied to the upper end of each half-split body 3 of the outer tube 4 from the outside and both of the half-split bodies 3, 3 are fallen toward the inside by utilizing a clearance S formed by the projection leveled parts 5 to separate each half-split body 3 from the concrete and lift it. Then, a post mounting anchor 23 is inserted into a post erection hole H to erect a handrail post.

Description

  The present invention relates to a handrail strut standing method for standing a handrail strut on a dam wall such as a veranda and a pillar standing hole forming mold used in this method.

  Wood that forms the lower end of the strut at the strut standing position of the formwork for the weir wall that is assembled and formed at the outdoor end of the veranda as a method of standing the handrail strut on the weir wall of the veranda formed of concrete Set up the support column standing hole forming mold, cast concrete into the weir wall mold, and after solidifying the concrete, remove the column support hole forming mold, and form the support column standing hole There is a method of inserting a lower end portion of a handrail support column or an anchor for mounting a column and fixing it with a mortar or a curable adhesive to stand upright.

  In the above method, when removing the pillar standing hole forming mold after the dam wall concrete is solidified, the concrete is fixed to the outer peripheral surface of the mold, so that it is difficult to remove, usually the mold The frame is smashed and removed with a hammer, etc., but it takes a lot of work to remove the frame, so that the work efficiency is deteriorated. It was very uneconomical because it was not possible.

  In view of the above circumstances, the present invention is a method for standing a handrail strut that can easily form a pillar standing hole and can improve the construction efficiency, and a pillar standing hole forming mold used in this method. The purpose is to provide.

  Means for solving the above-described problems will be described with reference numerals in the embodiments described later. The method for erecting the handrail strut according to the first aspect of the present invention is provided vertically on both sides of the outer peripheral surface of the inner cylinder 2. The bottomed cylindrical inner cylinder 2 projecting from the gap-forming convex step 5 extending to the opposite end surfaces 3o and the end surfaces 3o of the halves 3 and 3, respectively, are opposite end surfaces 5o of the convex step portions 5, respectively. A column-standing hole forming mold 1 constituted by a pair of halves 3 and 3 that are externally fitted to the inner cylinder 2 so as to abut on 5o is placed inside the dam wall mold 13 The concrete 20 is placed in the mold frame 13 after being suspended, and after the solidification, the inner cylinder 2 of the mold 1 is pulled out from the outer cylinder 4, and then each half of the outer cylinder 4 is divided. The upper end of the body 3 is hit from the outside, and the halves 3 and 3 are respectively collapsed inward using the gaps S formed by the convex steps 5. By doing so, each halved body 3 is separated from the concrete 20 and pulled up, and a handrail column or column mounting anchor 23 is inserted into the column standing hole H of the dam wall 12 formed thereby. The feature is that the sliding column is erected.

  The invention according to claim 2 is a mold for forming a pillar standing hole used in the method for standing the handrail pillar according to claim 1, wherein a gap is formed extending vertically on both sides of the outer peripheral surface of the inner cylinder 2. The bottomed cylindrical inner cylinder 2 projecting from the convex stepped portion 5 and the opposed end surfaces 3o, 3o of the halves 3, 3 are in contact with both end surfaces 5o, 5o of the convex stepped portions 5. An outer cylinder 4 made of a pair of halves 3 and 3 fitted on the inner cylinder 2, and an attachment piece for attaching the inner cylinder 2 to the dam wall mold 13 at the upper end of the inner cylinder 2 7 is provided, and each half 3 of the outer cylinder 4 is provided with a notch groove 8 for bolt insertion at the upper end portion, and a bolt 6 protruding from the outer surface of the upper end portion of the inner cylinder 2 is inserted into the notch groove 8. By tightening with a nut 10, the outer cylinder 4 fitted on the inner cylinder 2 is fixed.

  According to a third aspect of the present invention, the inner cylinder 2 is formed in a tapered shape and the halves 3 and 3 of the outer cylinder 4 are formed in a tapered shape. It is formed so as to be fitted to the tapered inner cylinder 2.

  According to a fourth aspect of the present invention, in the mold for forming a pillar standing hole according to the second or third aspect, each of the halves 3 of the outer cylinder 4 has a large number of protrusions 11 formed on the outer surface thereof. And

  The effect of the invention by the above solution will be described with reference numerals of the embodiments described later. According to the invention according to claim 1, the pillar-standing hole forming mold 1 is replaced with the dam wall mold 13. After suspending and supporting at the position where the support column is erected, concrete 20 is placed in the dam wall mold 13, and after solidification, the inner cylinder 2 of the mold 1 is pulled out from the outer cylinder 4. By hitting the upper end of the half-divided body 3 from the outside and using the gap S formed by the convex stepped part 5 to cause the half-divided bodies 3, 3 to fall down, 3 was separated from the concrete 20 and pulled up, and a pillar mounting anchor 23 (or a handrail pillar) was inserted into the pillar standing hole H of the dam wall 12 formed thereby to stand the handrail pillar. From the above, the pillar standing hole H can be easily and easily formed at the pillar standing position of the dam wall 12 to increase the construction efficiency. It is improved, yet since the post elevational 設穴 forming die 1 can be many times repeated use, it is very economical.

  According to the second aspect of the present invention, the column-standing-hole-forming mold 1 has a bottomed cylindrical inner shape in which the gap-forming convex step portions 5 extending vertically are provided on both sides of the outer peripheral surface of the inner tube 2. A pair of halves 3, 3 that are externally fitted to the inner cylinder 2 so that the opposite end faces 3o, 3o of the cylinder 2 and the halves 3, 3 are in contact with both end faces 5o, 5o of each convex stepped portion 5. 3, and an attachment piece 7 for attaching the inner cylinder 2 to the dam wall mold 13 is provided at the upper end of the inner cylinder 2, and each half 3 of the outer cylinder 4 is provided. Is provided with a bolt insertion notch groove 8 at the upper end portion, and a bolt 6 protruding from the upper end portion of the inner cylinder 2 is inserted into the notch groove 8 and tightened with a nut 10 to be externally fitted to the inner cylinder 2. Since the outer cylinder 4 is fixed, in use, the entire metal fitting 1 can be suspended by simply attaching the attachment piece 7 to the required portion of the weir wall mold 13. When the inner cylinder 2 is pulled out, the inner cylinder 2 can be easily pulled out by loosening and removing the nut 10 from the bolt 6 and pulling up the attachment piece 7.

  According to the invention of claim 3, the inner cylinder 2 is formed to be tapered and tapered, and the two halves 3 and 3 of the outer cylinder 4 are fitted to the tapered inner cylinder 2. Since it is formed, the pulling-out operation of the inner cylinder 2 is further facilitated.

  According to the invention of claim 4, each half 3 of the outer cylinder 4 has a large number of projections 11 formed on the outer surface thereof, and the projection 11 causes a large number of projections 11 to be formed on the inner wall surface of the column erect hole H. Since the concave portion 22 is formed, the cement mortar 24 or the curable adhesive injected when the column lower end portion or the column mounting anchor 23 is inserted into the column standing hole H enters the recess 22 and is cured, The handrail support column can be firmly erected in the support column standing hole H by the biting effect of the cement mortar 24 or the curable adhesive on the inner wall surface of the support column standing hole H.

It is a perspective view which shows one Embodiment of the support | pillar standing hole formation metal mold | die which concerns on this invention. (a) is a front view of the same mold, and (b) is a side view. It is a perspective view of the state which decomposed | disassembled the metal mold | die same as the above into the outer cylinder which consists of an inner cylinder and a pair of halves. (a) is a front view of the inner cylinder, (b) is a side view, (c) is a plan view, and (d) is a bottom view. (a) is explanatory drawing which shows the mold for dam walls, and the support | pillar standing hole formation metal mold | die suspended by this, (b) is the sectional view on the AA line of (a). This shows how to set up the handrail struts. (A) is an explanatory diagram of the concrete placed in the dam wall formwork, and (b) is the pillar standing hole forming mold buried in concrete. It is explanatory drawing of the state cut away from the mold for dam walls. It is explanatory drawing of the state which has pulled out the inner cylinder from the metal mold | die for pillar standing hole formation buried in concrete. (a) is explanatory drawing which shows a pair of half split body of the outer cylinder which remained after pulling out the inner cylinder, (b) is explanatory drawing which shows the state which has pulled out the half split body from the support | pillar standing hole. (a) is an explanatory view showing a state in which the handrail support column is inserted into the formed support column standing hole, and (b) is a figure in which the lower end portion of the handrail support column inserted into the support column mounting hole is hardened with mortar or the like. It is explanatory drawing which shows a state. It is a perspective view in the state where a handrail was installed.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. A post-standing-hole forming mold 1 shown in FIGS. 1 to 3 includes a bottomed cylindrical inner cylinder 2 and a pair of halves on both sides. It is comprised by the outer cylinder 4 which consists of the split bodies 3 and 3. FIG. As can be seen from FIGS. 3 and 4, the inner cylinder 2 is formed into a tapered bottomed rectangular tube with a stainless steel plate and is tapered by front and rear side plates 2 a and 2 a, left and right side plates 2 b and 2 b, and a bottom plate 2 c, On each of the left and right side plates 2b, a protruding step portion 5 for forming a gap extending in the vertical direction protrudes from the center portion in the width direction. Further, the front and rear side plates 2a of the inner cylinder 2 are provided with bolts 6 projecting outward from the inner side of the side plate 2a at the center in the width direction of the upper end. Further, an attachment plate (attachment piece) 7 for attaching the inner cylinder 2 to a later-described dam wall mold is fixed to the upper end portion of the inner cylinder 2 between the left and right side plates 2b and 2b. The mounting plate 7 is provided with two vertically long bolt insertion long holes 7a and a horizontally long metal drawing long hole 7b.

  As shown in FIGS. 1 and 3, the half halves 3 and 3 of the outer cylinder 4 are formed so as to be externally fitted from both the front and rear sides of the tapered inner cylinder 2. The opposite end faces 3o and 3o of the halves 3 and 3 are brought into contact with both side end faces 5o and 5o of the protruding step portion 5 projecting from the left and right side plates 2b of the inner cylinder 2 at the time of external fitting. . Each halved body 3 is formed of a front plate portion 3a and left and right side plate portions 3b, 3b in a substantially U-shaped cross section. Further, as shown in FIG. 3, each half-divided body 3 is formed with a notch groove 8 for bolt insertion at the upper end portion, and a bolt 6 protruding from the outer surface of the upper end portion of the inner cylinder 2 is inserted into the notch groove 8. The outer cylinder 4 fitted on the inner cylinder 2 is fixed by being inserted and tightened with a nut 10 via a washer 9. Each half 3 is formed with a large number of protrusions 11 on the outer surface of the front plate portion 3a.

  1 and 2 show a state in which an outer cylinder 4 consisting of a pair of halves 3 and 3 on both sides is fitted and fixed to the inner cylinder 2, and FIG. 3 shows a pair of halves on both sides forming the outer cylinder 4. The state which removed the bodies 3 and 3 from the inner cylinder 2 is shown. In order to form the post-standing hole forming mold 1 for attaching the half halves 3, 3 of the outer cylinder 4 to the inner cylinder 2 from the state shown in FIG. 3, the halves 3, 3 are attached to the inner cylinder 2. Inserting a notch groove 8 protruding from the outer surface of the upper end portion of each half 3 into the bolt 6 on the inner cylinder 2 side, and screwing a nut 10 to the bolt 6 via a washer 9 while approaching the front and rear side portions. By tightening, the half halves 3 and 3 are fitted into the inner cylinder 2, and the opposite end faces 3 o and 3 o of the half halves 3 and 3 abut against both side end faces 5 o and 5 o of the convex step portion 5. Thus, the post-standing hole forming mold 1 as shown in FIGS. 1 and 2 is formed.

  1 and 2, when separating the inner cylinder 2 and the outer cylinder 4 from the column-standing hole forming mold 1 in the state shown in FIGS. 1 and 2, the nut 10 is loosened and the nut 10 is removed from the bolt 6 together with the washer 9. After that, the inner cylinder 2 may be pulled upward from both halves 3 and 3 of the outer cylinder 4.

  Next, the standing method of the handrail support | pillar by use of the above-mentioned support | pillar standing hole formation metal mold | die 1 is demonstrated, referring FIGS.

  5A is a cross-sectional view showing a dam wall mold 13 for forming the dam wall 12 of the veranda as shown in FIG. 10, and FIG. 5B is a cross-sectional view taken along the line AA of FIG. is there. As is well known, the dam wall mold 13 is formed by an indoor dam plate 13a made of plywood or the like, an outdoor dam plate 13b, a bottom plate 13e, and support frames 13c and 13d made of square members or the like. A reinforcing bar 14 is disposed inside the frame. The support frame 13d is used as a mold for supporting the lower end side of the indoor dam plate 13a and forming the drainage channel 15 (see FIG. 10) of the veranda. Further, as shown in FIG. 5 (a), triangular strip-shaped protrusions 13f are provided on the upper end of the inner wall surface of the indoor side dam plate 13a and the upper and lower end portions of the inner wall surface of the outdoor dam plate 13b. The protruding strip 13f is for chamfering the corner of the dam wall 12 to be formed. Further, a protrusion 13g for draining is provided on the upper wall surface of the bottom plate 13e.

  Now, as shown in FIGS. 5 (a) and 5 (b), the dam wall mold 13 is suspended from the dam wall mold 13 as shown in FIGS. The wooden bases 16 and 16 are placed on the support frames 13c and 13c of the indoor side barrier plate 13a and the outdoor side barrier plate 13b corresponding to the standing position of the pillars, and the beam material made of an angle material over both the bases 16 and 16 is provided. 17, the beam member 17 is fixed to the dam wall mold 13 by driving or screwing a nail or a wood screw 21 so as to extend from the horizontal piece 17a of the beam member 17 through the base 16 to the support frame 13c.

  From the two bolt insertion holes (not shown) provided in the vertical piece 17b of the beam member 17 fixed at a required position on the dam wall mold 13 in this way, the mounting plate ( The bolts 18 are inserted into the two long holes 7a and 7a provided in the attachment piece 7), the nuts 19 are screwed together, the heights are adjusted appropriately using the long holes 7a, and then the nuts 19 are tightened. Thus, as shown in FIGS. 5 (a) and 5 (b), the column-standing hole forming mold 1 is suspended and supported at the column-standing position in the dam wall 7. FIG. At this time, the upper end portions of the inner and outer cylinders 2 and 4 of the mold 1 have a required length (for example, about one fifth of the length of the inner and outer cylinders 2 and 4), and the concrete placement upper limit line in the dam wall mold 13 The mold 1 is suspended so as to be positioned above L (see FIG. 5 (a)), and bolts 6 and nuts 10 for fixing the outer cylinder 4 to the inner cylinder 2 are driven as described later. So that it is not buried in the concrete 20 to be used.

  As shown in FIG. 6 (a), the concrete 20 is placed in the dam wall mold 13 after the column-standing hole forming mold 1 is suspended in the dam wall mold 13 as described above. To do. At this time, the surface of the mold 1 that is in direct contact with the concrete 20 is the surface of each of the halves 3 and 3 that form the outer cylinder 4, the lower surface of the bottom plate 2c of the inner cylinder 2, and the projections for forming the gaps. It is a surface portion of the stepped portion 5. When the concrete 20 is solidified, as shown in FIG. 6 (b), the bolts 18 and nuts 19 fixing the mounting plate 7 of the mold 1 to the beam member 17 are removed, and the nail or wood screw 21 is removed. Then, the beam member 17 and the pedestal 16 are removed. The dam wall mold 13 is disassembled and removed when the concrete 20 is sufficiently solidified, and the formed dam wall 12 is exposed by dismantling and removing the mold 13.

  Then, as shown in FIG. 6 (b), the inner cylinder 2 and the outer cylinder 4 of the pillar standing hole forming die 1 embedded in the dam wall 7 with the upper end portion remaining at the required length are joined. After the nut 10 of the bolt 6 is loosened and removed, the inner cylinder 2 of the mold 1 is pulled out from the outer cylinder 4 as shown in FIG. In this case, the entire surface of each half 3 that forms the outer cylinder 4 is bonded to the concrete wall surface of the column erect hole H formed by the mold 1, but the inner cylinder 2 is the lower surface of the bottom plate 2c. The inner cylinder 2 is covered with the halves 3 and 3 of the outer cylinder 4 for the most part on the surface side, just by bonding the surface part of the convex part 5 for forming the gaps and the gap-forming convex part 5 to the concrete wall surface. Therefore, the bottom surface of the bottom plate 2c of the inner cylinder 2 and the gap are applied to the inner cylinder 2 by applying a suitable blow to the upper end of the gap forming convex portion 5 of the inner cylinder 2 from the outside. Since the surface portion of the forming convex step portion 5 is peeled off from the concrete wall surface of the pillar standing hole H, a bar material such as a bar is thrust into the fitting extraction hole 7b of the attachment plate (attachment piece) 7 and pulled up. Thus, the mold 1 can be pulled out relatively easily.

  When the inner cylinder 2 is pulled out from the outer cylinder 4 as described above, only the pair of halves 3 and 3 forming the outer cylinder 4 are left in the dam wall 12. As shown in FIG. 7, gaps S and S are formed between the end faces 3o and 3o facing each other by the gap forming convex steps 5 and 5 of the extracted inner cylinder 2, so that each half As shown in the figure, the upper end portion of the split body 3 is hit with an impact P, and the half split body 3 is tilted inward as shown in FIG. As shown in FIG. 8 (a), the formed pillar standing hole H can be completely peeled off from the concrete wall surface, so that the pillar standing hole is formed in the dam wall 12 as shown in FIG. 8 (b). H is formed. In addition, a large number of concave portions 22 are formed on the inner wall surface of the column standing hole H by the large number of convex portions 11 on the outer surface of each half body 3.

  As shown in FIG. 9 (a), the pillar mounting anchor 23 is inserted into the pillar standing hole H formed at the pillar standing position of the dam wall 12 as shown in FIG. 9 (b). Cement mortar 24 is injected. In place of the cement mortar 24, a curable adhesive may be injected. In the case of the cement mortar 24, since it takes 1 to 2 days to harden, the tubular handrail support 25 is fitted to the support attaching anchor 23 after the hardening. As shown in FIG. 9 (b), since the cement mortar 24 enters and hardens in a large number of recesses 22 formed in the inner wall surface of the upright hole H, the bite of the cement mortar 24 that has entered the recesses 22 is cured. Due to the attachment effect, the column mounting anchor 23 is effectively integrated with the dam wall 12 via the cement mortar 24, and the column mounting anchor 23 can be firmly installed in the column standing hole H of the dam wall 12.

  Then, as shown in FIG. 10, a cylindrical handrail support column 25 is fitted to the support column mounting anchor 23, and this cylindrical handrail support column 25 is fixed to the support column mounting anchor 23 with screws 26. By attaching the crosspiece 28 and the vertical crosspiece 29, the handrail 30 can be installed.

  In the embodiment shown in FIG. 9 and FIG. 10, a cement mortar 24 or a curable adhesive is prepared by inserting a column mounting anchor 23 into a column standing hole H formed in the dam wall 12 by the column standing hole forming mold 1. The handrail strut 25 is fitted to the anchor 23, but the lower end portion of the handrail strut is directly inserted into the pillar standing hole H, and the cement mortar 24 or a curable adhesive is used. It may be fixed and erected.

  As described above, the method for erecting the handrail strut according to the present invention suspends the strut standing hole forming mold 1 from the strut standing position in the weir wall mold 13 and then uses it for the weir wall. Concrete 20 is placed in the mold 13, and after the solidification, the inner cylinder 2 of the mold 1 is pulled out from the outer cylinder 4, and then the upper end of each half 3 of the outer cylinder 4 is hit from the outside, Each half 3 is separated from the concrete 20 and pulled up by causing the two halves 3 and 3 to fall inward using the gap S formed by the convex step 5, thereby Since the column mounting anchor 23 (or handrail column) is inserted into the column support hole H of the formed dam wall 12 so that the column rail column is erected, the column is placed at the column erection position of the dam wall 12. Standing hole H can be formed easily and easily, and the construction efficiency can be greatly improved. Because it can be any number of times repeated use, it is very economical.

  Further, the support-standing-hole-forming mold 1 includes a bottomed cylindrical inner cylinder 2 projecting vertically projecting gap forming step portions 5 extending vertically on both sides of the outer peripheral surface of the inner cylinder 2, and both halves. From the outer cylinder 4 made up of a pair of halves 3 and 3 that are externally fitted to the inner cylinder 2 so that the opposite end faces 3o and 3o of the third and third faces abut both end faces 5o and 5o of each convex step portion 5 In the upper end portion of the inner cylinder 2, an attachment piece 7 for attaching the inner cylinder 2 to the dam wall formwork 13 is provided, and each half-divided body 3 of the outer cylinder 4 is inserted into a bolt at the upper end portion. A notch groove 8 is provided, and a bolt 6 protruding from the upper end portion of the inner cylinder 2 is inserted into the notch groove 8 and tightened with a nut 10 so that the outer cylinder 4 fitted to the inner cylinder 2 is fixed. Therefore, in use, the entire metal fitting 1 can be suspended and the inner cylinder 2 can be pulled out simply by attaching the attachment piece 7 to the required portion of the dam wall mold 13. Sometimes, the inner cylinder 2 can be easily pulled out by loosening the nut 10 and removing it from the bolt 6 and pulling up the attachment piece 7.

  Further, in this mold 1, the inner cylinder 2 is formed in a tapered shape so that both the half halves 3 and 3 of the outer cylinder 4 are formed in a tapered manner so as to be externally fitted to the tapered inner cylinder 2. Therefore, the operation of pulling out the inner cylinder 2 is further facilitated.

DESCRIPTION OF SYMBOLS 1 Support | pillar standing hole formation die 2 Inner cylinder 3 Half split body 3o End face of half split body 4 Outer cylinder 5 Convex step part for gap formation 5o Side end face of convex step part 6 Bolt 7 Mounting plate (attachment piece)
8 Notch groove for bolt insertion 10 Nut 11 Protrusion 12 Weir wall 13 Formwork for weir wall

Claims (4)

  The bottomed cylindrical inner cylinder projecting vertically projecting step portions for forming gaps extending vertically on both side portions of the outer peripheral surface of the inner cylinder, and the opposite end surfaces of both halves contact the both end surfaces of each convex step portion. After supporting a pillar standing hole forming mold constituted by a pair of halves that are externally fitted to the inner cylinder in such a manner as to be suspended at the pillar standing position in the dam wall mold, Concrete is placed in the mold, and after the solidification, the inner cylinder of the mold is pulled out from the outer cylinder, and then the upper end of each half of the outer cylinder is hit from the outside, By making both halves fall inward using the gaps formed, each half is separated from the concrete and pulled up, and in the pillar standing hole of the dam wall formed thereby A method for erecting a handrail post in which a handrail post is inserted by inserting a handrail post or a post mounting anchor.   A pillar-forming hole forming mold for use in the handrail-strut erection method according to claim 1, wherein a gap-forming convex step portion extending vertically is provided on both sides of the outer peripheral surface of the inner cylinder. The bottom cylinder-shaped inner cylinder and the outer cylinder formed of a pair of halves that are externally fitted to the inner cylinder so that the opposite end surfaces of both halves are in contact with both end surfaces of the convex steps, A mounting piece for mounting the inner cylinder to the dam wall mold is provided at the upper end of the cylinder, and a notch groove for inserting a bolt is provided at the upper end of each half of the outer cylinder. A column-standing hole forming mold configured to fix the outer cylinder fitted to the inner cylinder by inserting a bolt projecting from the outer surface of the upper end of the cylinder and tightening with a nut.   3. The pillar standing hole forming hole according to claim 2, wherein the inner cylinder is formed in a tapered shape with a narrowed bottom, and both halves of the outer cylinder are formed so as to be externally fitted to the tapered cylindrical inner cylinder. Mold.   The mold for forming a pillar standing hole according to claim 2 or 3, wherein each half of the outer cylinder has a plurality of protrusions formed on an outer surface thereof.

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