JP2017003451A - Inspection method of anchor member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more correctly determine that pull-out strength of an anchor member is normal.SOLUTION: A method for inspecting pull-out strength of an anchor bolt 1 to a foundation body 2 is configured so that, in a state in which a structure 3 is attached to the foundation body 2 by screwing of the anchor bolt 1 and a nut 4, when the nut 4 is tightened with a torque wrench 6, if the nut 4 does not rotate, and a torque applied to the nut 4 is equal to or higher than a prescribed value, it is determined that the pull-out strength of the anchor bolt 1 is normal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an improved technique of a method for inspecting the pullout strength of an anchor member installed on a foundation body with respect to the foundation body.

  As is well known, for example, an anchor member such as an anchor bolt is installed on the foundation body in order to fix a structure such as a road sign to the foundation body such as concrete.

  The pullout strength of the anchor member with respect to the base body is very important because it directly relates to the strength of fixing the structure to the base body. That is, when the pullout strength of the anchor member with respect to the base body is low, the fixing strength of the structure to the base body is low. Therefore, not only immediately after the anchor member is installed on the foundation body, but also after the structure is attached to the foundation body by screwing between the anchor member and a tightened member such as a nut. Even regular inspections were desired.

  As a method for inspecting the pullout strength of such an anchor member, for example, Patent Document 1 proposes the following method. In other words, it is confirmed whether a predetermined torque can be obtained when a nut is screwed from the tip of an anchor bolt projecting on the top surface of the gantry placed on the foundation to the top surface of the gantry and the nut is tightened with a torque wrench. Then, the pullout strength of the anchor bolt is diagnosed.

JP-A-10-48112

  However, in the inspection method of Patent Document 1, it is confirmed whether or not a predetermined torque is obtained when the nut is tightened with a torque wrench, and when the predetermined torque is obtained, the pullout strength of the anchor bolt is normal. Deciding. However, even when a predetermined torque is obtained when a member to be tightened such as a nut is tightened with a torque wrench, a situation may occur in which the pullout strength of the anchor member such as an anchor bolt is not normal. There was sex.

  In view of the above circumstances, an object of the present invention is to more accurately determine that the pullout strength of an anchor member is normal.

  The method for inspecting an anchor member according to the present invention, which was created to solve the above-mentioned problems, is installed on the foundation body in order to attach the structure to the foundation body by screwing with a tightening member that can be tightened with a torque wrench. A method for inspecting a pulling strength of the anchor member with respect to the base body, wherein the structure is attached to the base body by screwing the anchor member and the tightened member. When the tightening member is tightened with the torque wrench, the pulling strength is increased when the tightening member does not rotate and the torque applied to the tightening member becomes a predetermined value or more. It is characterized by judging that is normal.

  Here, the anchor member is, for example, an anchor bolt that is installed in advance before the foundation body is completed, a post-installed anchor that is installed in the foundation body after the foundation body is completed, and the like (hereinafter the same). Moreover, as a to-be-clamped member, the member which has external thread parts, such as a volt | bolt, for example, the member which has internal thread parts, such as a nut, is mentioned, for example (hereinafter the same).

  Moreover, the predetermined value of torque is a value of torque corresponding to the value of the pulling strength with respect to the base body required for the anchor member (hereinafter the same). The predetermined value of the torque can be calculated by a known calculation formula. For example, if it is an approximate value, the value of the required pulling strength (axial force) is F (kN), the value of the torque corresponding to this pulling strength is T (N · m), and the anchor member or tightening member When the outer diameter of the male screw part is d (mm), T = 0.2 × F × d.

  In the above configuration, when the tightening member is tightened with a torque wrench, the anchor member does not rotate and the torque applied to the tightening member exceeds a predetermined value. It is determined that the pullout strength of the steel is normal. Therefore, for example, even when the torque applied to the member to be tightened exceeds a predetermined value, a situation occurs in which the pullout strength of the anchor member such as the member to be tightened is not normal. In this case, it can be determined that the pullout strength is normal. In other words, according to the anchor member inspection method of the present invention, it is possible to more accurately determine that the pullout strength of the anchor member is normal.

  Moreover, in said structure, a to-be-tightened member is fastened with a torque wrench in the state in which the structure was attached to the base body by screwing of an anchor member and a to-be-tightened member. Therefore, it is not necessary to prepare for inspection such as loosening or removing the tightened member and mounting the inspection instrument. For this reason, the pullout strength of the anchor member can be easily inspected, whereby the pullout strength of a large number of anchor members can be inspected.

  In the above configuration, the anchor member is an anchor bolt, and the tightened member is a nut, and when the nut is tightened with the torque wrench, the nut rotates and is applied to the nut. If the torque remains below the predetermined value, it may be determined whether or not the anchor bolt is rotating.

  If the nut rotates when the nut is tightened with a torque wrench and the torque applied to the nut remains below the specified value, the anchor bolt or the surrounding base body breaks and the pullout strength of the anchor bolt May have declined. However, even in this case, there is a possibility that the pullout strength of the anchor bolt is not lowered and the nut is merely loosened. As in this configuration, when the nut rotates and the torque applied to the nut remains below a predetermined value, it is determined whether or not the anchor bolt rotates, and if the anchor bolt does not rotate The possibility of loosening of the nut is high. Therefore, according to this configuration, it is possible to distinguish between loosening of the nut and reduction of the pullout strength of the anchor bolt.

  As described above, according to the present invention, it can be determined more accurately that the pullout strength of the anchor member is normal. In addition, it is possible to perform inspection of a large number of anchor members by facilitating the inspection of the pullout strength of the anchor member on the base body.

It is a schematic fragmentary sectional view which shows the periphery of the anchor member of the test object of the inspection method of the anchor member which concerns on embodiment of this invention. It is a flowchart which shows the inspection method of the anchor member which concerns on embodiment of this invention. It is a flowchart which shows the modification of the inspection method of an anchor member. It is a schematic fragmentary sectional view which shows the periphery of the modification of an anchor member.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic partial cross-sectional view showing the periphery of an anchor member to be inspected in the anchor member inspection method according to the embodiment of the present invention. An anchor bolt 1 as an anchor member is a sleeve driving type post-installed anchor. The anchor bolt 1 includes a bolt part 1a and a sleeve part 1b through which the bolt part 1a is inserted. The bolt portion 1a has a male screw portion 1c at one end and a truncated cone-shaped head portion 1d at the other end. The sleeve portion 1b has an expanded portion 1e that is expanded in the radial direction by engagement with the head portion of the bolt portion 1a. The anchor bolt 1 is fixed to the hole 2a of the base body 2 by the extended portion 1e.

  The anchor bolt 1 is installed on the foundation body 2 in order to attach the structure 3 to the foundation body 2. The anchor bolt 1 has a structure 3 attached to the base body 2 by screwing of a male screw portion 1c with a female screw portion of a nut 4 as a member to be tightened. The structure 3 is, for example, a road sign or road illumination. The foundation body 2 has a predetermined strength and is, for example, concrete, stone wall or the like.

  The structure 3 has a mounting plate portion 3 a that is attached in a state of being in contact with the base body 2. The mounting plate portion 3a is provided with a fool hole 3b, and the male screw portion 1c of the anchor bolt 1 is inserted into the fool hole 3b. A washer 5 is fitted into the male screw portion 1c protruding from the fool hole 3b, and the female screw portion of the nut 4 is screwed into the male screw portion 1c protruding from the washer 5. The attachment plate portion 3a is sandwiched between the base body 2 and the nut 4 by screwing the anchor bolt 1 and the nut 4, whereby the structure 3 is attached and fixed to the base body 2.

  A torque wrench 6 for tightening the nut 4 to inspect the pull-out strength of the anchor bolt 1 has a spanner-type head portion 6a. In a state where the head portion 6a is attached to the nut 4 screwed into the male screw portion 1c of the anchor bolt 1, the tip portion of the male screw portion 1c can be visually recognized. Further, the torque wrench 6 has a display portion 6 b that displays the value of torque applied to the nut 4.

  Next, an anchor member inspection method according to an embodiment of the present invention will be described with reference to the flowchart of FIG.

  In the method for inspecting an anchor member of the present invention, as shown in FIG. 1, the structure 3 is implemented with the structure 3 attached to the base body 2 by screwing the anchor bolt 1 and the nut 4.

  First, in step S <b> 1, the head portion 6 a of the torque wrench 6 is attached to the nut 4, and the nut 4 is tightened by the torque wrench 6.

  Next, in step S2, it is determined whether or not the nut 4 does not rotate and the torque applied to the nut 4 is equal to or greater than a predetermined value. Specifically, it is determined whether or not the nut 4 is rotated by visually recognizing the nut 4, and the torque value displayed on the display unit 6 b of the torque wrench 6 is checked to determine the torque applied to the nut 4. It is determined whether or not a predetermined value is exceeded. Whether or not the nut 4 is rotated is determined indirectly by whether or not the torque wrench 6 is rotated, by directly checking the torque wrench 6 or visually checking the nut wrench 6 instead of directly viewing the nut 4. May be.

  When the nut 4 does not rotate and the torque applied to the nut 4 is equal to or higher than a predetermined value (when it is Yes) as a result of the determination in step S2, the pullout strength of the anchor bolt 1 is normal. (Step S3). In other cases (when No), it is determined that the pullout strength of the anchor bolt 1 is abnormal (step S4).

  In addition, after confirming that the torque applied to the nut 4 has reached a predetermined value or more, it is preferable to immediately stop applying the torque by the torque wrench 6. This is because if the torque is excessively applied, the anchor bolt 1 or the surrounding base body 2 may be destroyed.

  In the above description, when the determination result of step S2 is No, it is determined that the pullout strength of the anchor bolt 1 is abnormal (step S4). However, the present invention is not limited to this. For example, as shown in FIG. 3, when the determination result in step S2 is No, the determination may be further performed. That is, it progresses to step S5 and it is determined whether the nut 4 rotates and the torque provided to the nut 4 remains below a predetermined value.

  As shown in FIG. 3, when the determination result of step S5 is No, it is determined that the anchor bolt 1 is abnormal (step S4). When the determination result of step S5 is Yes, it progresses to step S6, visually recognizes the anchor bolt 1, and determines whether the anchor bolt 1 is rotating.

  If the determination result in step S6 is Yes, the pullout strength of the anchor bolt 1 is abnormal, assuming that the pullout strength of the anchor bolt 1 is reduced by destroying the anchor bolt 1 or the surrounding basic body 2. Judgment is made (step S4). If the determination result of step S6 is No, it is determined that the nut 4 is loose (step S7). In this case, as indicated by a dotted line, the nut may be retightened with an appropriate torque (step S8), and then the process may return to step S1 to perform the inspection again.

  In the inspection method of the anchor bolt 1 according to the embodiment of the present invention configured as described above, the following effects can be enjoyed.

  When the nut 4 is tightened with the torque wrench 6 and the nut 4 does not rotate and the torque applied to the nut 4 exceeds a predetermined value, it is determined that the pullout strength of the anchor bolt 1 is normal. To do. Therefore, for example, when a situation occurs in which the pull-out strength of the anchor bolt 1 is not normal such that the nut 4 rotates even when the torque applied to the nut 4 exceeds a predetermined value. It can be avoided that the pulling strength is normal. That is, according to the inspection method of the anchor bolt 1 of the present embodiment, it can be more accurately determined that the pullout strength of the anchor bolt 1 is normal.

  Further, the nut 4 is tightened with the torque wrench 6 while the structure 3 is attached to the base body 2 by screwing the anchor bolt 1 and the nut 4. Therefore, it is not necessary to prepare for the inspection such as loosening or removing the nut 4 and mounting the inspection instrument. For this reason, the pullout strength of the anchor bolt 1 can be easily inspected, whereby the pullout strength of a large number of anchor bolts 1 can be inspected.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical idea. For example, in the said embodiment, although the structure 3 was attached to the upper surface of the base body 2, the structure 3 may be attached to the slope of a base body, a side surface, or a lower surface. In this case, in order to inspect the pull-out strength of the anchor bolt 1, when an inspection method in which an inspection instrument is mounted by loosening or removing the nut 4 is used, the nut 4 is loosened or removed. There is a possibility that the structure 3 falls off from the base body 2. Therefore, the inspection method of the present invention that does not require loosening or removing the nut 4 becomes more meaningful.

  Further, in the above embodiment, the anchor bolt 1 of the anchor member has the male screw portion 1c, and the nut 4 of the member to be tightened to be tightened by the torque wrench 6 has the female screw portion. And the member to be tightened may have a male screw part. For example, as shown in FIG. 4, when the present invention is applied to a post-installed anchor of a tightening type cone nut type, the anchor member includes a nut portion 7a and a sleeve portion 7b, and the nut portion 7a has a female screw. Part. And a to-be-tightened member is the volt | bolt 8, and has the external thread part 8a. In this case, the sleeve portion 7b has an expanded portion 7c that is expanded in the radial direction by engagement with the tapered portion of the nut portion 7a. The anchor member is fixed to the hole 2a of the base body 2 by the expanded portion 7c.

  Note that the post-installed anchor of the tightening type cone nut type includes a bolt 8 and a washer 9 in addition to the nut portion 7a and the sleeve portion 7b. Thus, the anchor member and the tightened member of the present invention include a case where the anchor member and the tightened member are part of the structure of the post-installed anchor.

  Moreover, in the said embodiment, although the head part 6a of the torque wrench 6 was a spanner type | mold, a type | mold other than this may be sufficient. However, if the head portion 6a of the type that covers the tip of the male screw portion 1c of the anchor bolt 1 when attached to the nut 4 is used, is the anchor bolt 1 not visible in step S6 and is the anchor bolt 1 rotated? Cannot determine whether or not.

1 Anchor bolt (anchor member)
2 Foundation body 3 Structure 4 Nut (tightened member)
6 Torque wrench 7a Nut (anchor member)
7b Sleeve (anchor member)
8 Bolt (Clamped member)

Claims (2)

A method for inspecting the pulling strength of the anchor member installed on the foundation body to attach the structure to the foundation body by screwing with a tightening member that can be tightened with a torque wrench,
When the tightening member is tightened with the torque wrench while the structure is attached to the base body by screwing the anchor member and the tightening member, the tightening member is A method for inspecting an anchor member, comprising: determining that the pull-out strength is normal when the torque applied to the member to be tightened is not less than a predetermined value. The anchor member is an anchor bolt, and the tightened member is a nut,
Whether the anchor bolt is rotating when the nut is rotated with the torque wrench and the torque applied to the nut remains below the predetermined value. The method for inspecting an anchor member according to claim 1, wherein the determination is performed.

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