JP2018003304A - Anchor reinforcing structure, anchor reinforcing method and anchor reinforcing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anchor reinforcing structure which can efficiently reinforce an anchor bolt, an anchor reinforcing method and an anchor reinforcing member.SOLUTION: A reinforcing member 11 is composed of a screw member 13 and a fixing member 15. In the screw member 13, a female screw part is formed at one end part, and a male screw part is formed at the other end part. A clearance between the female screw part and the male screw part becomes a shank. Here, a diameter of the shank is smaller than a diameter of a trough part of the male screw part. The fixing member 15 can accommodate the screw member 13 therein. A hole 25 for allowing the insertion of the male screw part and the shank is formed at one end part of the fixing member 15. The female screw part is connected to a screw part 9a of an anchor bolt 9. In this state, the fixing member 15 is arranged so as to cover the screw member 13, and the male screw part is upwardly protruded from the hole 25 of the fixing member 15. Furthermore, a nut 17 is arranged at the male screw part, and fixed to an upper part of the fixing member 15.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an anchor reinforcement structure, an anchor reinforcement method, and an anchor reinforcement member for an anchor bolt that fixes, for example, a base plate of a column base.

  In order to prevent the collapse of the structure due to an earthquake, a structure such as a pillar is required to have a seismic strength of a predetermined level or more. However, since structures that were constructed before the current seismic standards were not required to be as severe as current seismic strength, the old structures may not meet the current seismic standards. However, it takes time and cost to newly rebuild all structures such as pillars.

  As a method for reinforcing such a structure, for example, there is a method of constructing a reinforced concrete root winding portion by placing concrete around a column base portion of an existing column. However, since concrete is constructed around the columns, a lot of work is required such as rebar and formwork, and the dimensions of the columns are increased by the amount of concrete, which hinders the convenience of the building.

  On the other hand, structures such as column bases are usually fixed to the foundation or ground by anchor bolts (for example, Patent Document 1).

JP 2006-104780 A

  If the strength and deformation capacity of the anchor bolt are not sufficient, there is a risk that the structure will fall due to the anchor bolt breaking or the like at an early stage. For this reason, reinforcement of an anchor bolt may be required for reinforcement of a structure. In particular, anchor bolts used in old steel-framed exposed column bases often have threaded parts that break before the shaft part of the anchor bolt is sufficiently plastically deformed. Many are scarce.

  The present invention has been made in view of such problems, and an object thereof is to provide an anchor reinforcement structure, an anchor reinforcement method, and an anchor reinforcement member that can efficiently reinforce an anchor bolt.

  In order to achieve the above-described object, a first invention is an anchor reinforcing structure, comprising an anchor bolt and a reinforcing member attached to an upper portion of the anchor bolt, wherein the reinforcing member is a screw member. And a fixing member capable of accommodating the screw member therein, wherein the screw member includes a female screw portion formed at one end portion, a male screw portion formed at the other end portion, and the female screw. And a shaft portion between the male screw portion, and the fixing member has a hole through which the male screw portion and the shaft portion can be inserted in one end portion, and the diameter of the shaft portion is The shaft portion is smaller than the diameter of the valley portion of the male screw portion, and the shaft portion starts plastic deformation with a load smaller than the load at which the screw portion of the anchor bolt breaks, and the screw member and the fixing surface of the fixing member The female screw part is the anchor bolt with a gap in between Are connected, in a state of covering the fixing member to the screw member, said male screw portion at the top of the fixing member is an anchor reinforcement structure, characterized in that it is fixed by a nut.

  The anchor bolt may fix the base plate of the column base.

  In the screw member, the female screw portion, the shaft portion, and the male screw portion may be configured separately, and the shaft portion and the female screw portion may be joined.

  The load at which the shaft portion starts plastic deformation may be larger than the load at which the threaded portion of the anchor bolt starts plastic deformation and smaller than the load at which the threaded portion breaks.

  The load at which the shaft portion starts plastic deformation may be smaller than the load at which the thread portion of the anchor bolt starts plastic deformation.

  According to the first invention, the reinforcing member is attached to the upper portion of the anchor bolt, the diameter of the shaft portion of the screw member of the reinforcing member is smaller than the diameter of the male screw portion of the screw member, and the shaft portion is the screw of the anchor bolt. Since plastic deformation starts with a load smaller than the load at which the portion breaks, a sufficient amount of deformation can be secured before the thread portion breaks during an earthquake or the like.

  Such a reinforcing member is particularly effective for reinforcing the anchor bolt that fixes the base plate of the column base.

  In addition, if the screw member is formed by joining the member of the female screw portion and the members of the shaft portion and the male screw portion separately, the screw member can be easily manufactured.

  If the load at which the shaft portion starts plastic deformation is larger than the load at which the threaded portion of the anchor bolt starts plastic deformation and is smaller than the load at which the threaded portion breaks, high strength and the effect of preventing the anchor from breaking can be obtained. It can be compatible.

  If the load at which the shaft portion starts plastic deformation is smaller than the load at which the threaded portion of the anchor bolt starts plastic deformation, the strength design of the shaft portion is easy.

  The second invention is a method of reinforcing an existing anchor, using an anchor reinforcing member comprising a screw member and a fixing member capable of accommodating the screw member therein, and removing a nut of an anchor bolt; A step of attaching a female screw portion formed at one end of the screw member to the anchor bolt, and a male screw portion formed at the other end of the screw member by covering the fixing member with the fixing member And a step of inserting the female screw portion and the shaft portion between the male screw portion into a hole provided in the fixing member, and the screw member covering the fixing member with the upper portion of the fixing member. A step of fixing the male screw portion with a nut, and there is a gap between the screw member and the fixing surface of the fixing member, and the diameter of the shaft portion is the diameter of the valley portion of the male screw portion. Smaller than the shaft portion, An anchor reinforcing method, wherein a threaded portion of Nkaboruto starts plastic deformation with a smaller load than the load to break.

  According to the second invention, the existing anchor bolt can be easily reinforced.

  3rd invention is a reinforcing member of an anchor, Comprising: A screw member and the fixing member which can accommodate the said screw member inside, The said screw member is formed in one edge part, An anchor bolt A female screw part connectable to the male screw part, a male screw part formed on the other end part, and a shaft part between the female screw part and the male screw part, and the fixing member has An anchor reinforcing member having a male screw part and a hole through which the shaft part can be inserted, wherein the diameter of the shaft part is smaller than the diameter of the valley part of the male screw part.

  According to the third invention, a reinforcing member capable of easily reinforcing the anchor bolt can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the anchor reinforcement structure which can reinforce an anchor bolt efficiently, an anchor reinforcement method, and an anchor reinforcement member can be provided.

The side view which shows the anchor reinforcement structure 1. FIG. The expanded sectional view of the anchor reinforcement structure 1. FIG. The exploded view of the reinforcement member 11. FIG. The figure which shows the other screw member 13. FIG. The figure which shows the existing column base 3. FIG. The figure which shows the state which removed the nut 27. FIG. The figure which shows the state which attached the screw member 13. FIG. The figure which shows the state which arrange | positions the fixing member 15 and attaches the nut 17. FIG. The figure which shows the state which the column base 3 displaced. The expanded sectional view of the F section of FIG. The figure which shows the relationship between a load and a deformation amount.

  Hereinafter, the anchor reinforcement structure 1 concerning embodiment of this invention is demonstrated. FIG. 1 is a side view showing an anchor reinforcement structure 1. In the following description, the anchor reinforcement structure 1 shows a reinforcement structure for the anchor bolt 9 that fixes the base plate 7 of the column base 3. However, the present invention is not limited to this, and any structure that is fixed by an anchor can be used. Applicable.

  The column base 3 is constructed on a floor 5 (for example, a foundation). A base plate 7 is fixed on the floor 5 with anchor bolts 9. A reinforcing member 11 is fixed to the upper part of the anchor bolt 9.

  2 is an enlarged cross-sectional view of a part A in FIG. 1, and FIG. 3 is an exploded cross-sectional view of the reinforcing member 11. The reinforcing member 11 includes a screw member 13 and a fixing member 15. As shown in FIG. 3, the screw member 13 is provided with a female screw part 19 at one end and a male screw part 21 at the other end. A shaft portion 23 is formed between the female screw portion 19 and the male screw portion 21. The diameter of the shaft portion 23 is smaller than the diameter of the valley portion of the male screw portion 21.

  In addition, although the internal thread part 19, the external thread part 21, and the axial part 23 may be integrally formed, the screw member 13 may be another body. For example, as shown to Fig.4 (a), the member which comprises the internal thread part 19 and the member which comprises the external thread part 21 and the axial part 23 may be a different body.

  In this case, a female screw portion 19 a is formed on the opposite side of the female screw portion 19, and a male screw portion 21 a is formed on the reverse side of the male screw portion 21. As shown in FIG. 4B, the screw member 13 is formed by joining the male screw portion 21a and the female screw portion 19a.

  The fixing member 15 can accommodate the screw member 13 therein. A hole 25 into which the male screw portion 21 and the shaft portion 23 can be inserted is formed at one end portion of the fixing member 15.

  As shown in FIG. 2, the female screw portion 19 is connected to the screw portion 9 a of the anchor bolt 9. In this state, the fixing member 15 is disposed so as to cover the screw member 13, and the male screw portion 21 protrudes upward from the hole 25 of the fixing member 15. Further, the male screw portion 21 is provided with a nut 17 and is fixed to the upper portion of the fixing member 15.

  At this time, a gap is formed between the tip of the screw member 13 (female screw portion 19) and the upper surface of the base plate 7 that is a fixing surface of the fixing member 15. That is, the screw member 13 does not contact the fixing surface of the fixing member 15.

  The screw member 13 and the fixing member 15 are made of steel, for example. The screw member 13 has a male threaded portion 21 formed by tapping at the end of a rod-shaped material, and the shaft portion 23 may be made thinner by, for example, cutting the rod-shaped material.

  Next, the reinforcement method of the existing column base using the reinforcement member 11 is demonstrated. FIG. 5 is a diagram showing the existing column base 3. As described above, the column base 3 is installed on the floor 5. The base plate 7 of the column base 3 is fixed to the floor 5 by anchor bolts 9 and nuts 27.

  From this state, the nut 27 is removed from the anchor bolt 9 as shown in FIG. 6 (arrow C in the figure). Therefore, the threaded portion 9a of the anchor bolt 9 is projected on the base plate 7.

  Next, as shown in FIG. 7, the screw member 13 is attached to the anchor bolt 9 protruding from the base plate 7. That is, the screw portion 9 a of the anchor bolt 9 and the female screw portion 19 of the screw member 13 are joined. At this time, as described above, a gap is formed between the lower end of the screw member 13 (female screw portion 19) and the upper surface of the base plate 7.

  Next, as shown in FIG. 8, the fixing member 15 is put on the screw member 13. At this time, the male screw portion 21 of the screw member 13 is inserted into the hole 25 of the fixing member 15 and protrudes above the fixing member 15. Furthermore, the anchor reinforcement structure 1 is constructed by attaching and fixing the nut 17 to the male screw portion 21 from above the fixing member 15 (arrow D in the figure).

  When a plurality of anchor bolts 9 are adjacent to each other, after attaching the screw members 13 to the respective anchor bolts 9, one fixing member 15 provided with a plurality of holes 25 is connected to the plurality of screw members 13. The screw members 13 may be fixed with nuts 17.

  Next, the function of the anchor reinforcement structure 1 will be described. FIG. 9 is a diagram showing a state in which the column base 3 is tilted in the event of an earthquake (arrow E in the figure), and FIG. When the base plate 7 is about to rise due to an earthquake, tensile stress is applied to the anchor bolt 9 and the screw member 13 of the reinforcing member 11.

  At this time, since the diameter of the shaft portion 23 of the screw member 13 is smaller than the diameter of the valley portion of the male screw portion 21, the shaft portion 23 is plastically deformed (elongated deformation) with a smaller load than the male screw portion 21 starts plastic deformation. (Arrow H in FIG. 10).

  Further, the shaft portion 23 starts plastic deformation with a load smaller than the load at which the threaded portion 9a of the anchor bolt 9 breaks. FIG. 11 is a diagram illustrating the relationship between the load of each part and the amount of deformation. In the figure, I is a view showing the behavior of the anchor bolt 9 (screw portion 9a). The threaded portion 9a starts plastic deformation with a predetermined load (L in the figure). However, since the anchor bolt has insufficient strength and deformability, the threaded portion breaks before the shaft portion of the anchor bolt is sufficiently plastically deformed (M in the figure).

  On the other hand, the shaft portion 23 of the screw member 13 behaves like K in the figure, for example. That is, the shaft portion 23 starts plastic deformation with a load smaller than the load at which the threaded portion 9a of the anchor bolt 9 breaks. For this reason, if the shaft part 23 is in a deformation amount range in which plastic deformation is possible, a load necessary for the screw part 9a to break is not applied to the screw part 9a.

  Thus, in this embodiment, it can prevent that the anchor bolt 9 fractures | ruptures because the axial part 23 preferentially plastically deforms. Further, since the load at which the shaft portion 23 starts plastic deformation is only slightly smaller than the load at which the screw portion 9a breaks, it is possible to suppress the shaft portion 23 from being easily plastically deformed with a small load. Can do. Thus, the load at which the shaft portion 23 starts plastic deformation is desirably larger than the load at which the screw portion 9a of the anchor bolt 9 starts plastic deformation and smaller than the load at which the screw portion 9a breaks.

  Here, the inclination allowed for the column base 3 is about 1/30 rad. For this reason, a necessary elongation amount is set in advance from the size of the base plate 7 and the inclination. Further, at this time, by setting the gap between the screw member 13 and the base plate 7 to be equal to or more than a necessary elongation amount, the elongation of the shaft portion 23 can be permitted with certainty.

  Note that the shaft portion 23 of the screw member 13 may behave as shown in FIG. That is, the shaft portion 23 may start plastic deformation with a load smaller than the load at which the threaded portion 9a of the anchor bolt 9 starts plastic deformation. Even if it does in this way, the load required for the thread part 9a to fracture | rupture is not provided to the thread part 9a in the deformation amount range in which the shaft part 23 can be plastically deformed. Further, it is easy to design the strength of the shaft portion 23 for starting the plastic deformation with a load smaller than the load at which the threaded portion 9a of the anchor bolt 9 starts the plastic deformation.

  In this case, as compared with the above-described example, the shaft portion 23 starts plastic deformation with a smaller load. However, since the plastic deformation of the screw portion 9a of the anchor bolt 9 can be prevented, the earthquake Later, the repair can be completed only by replacing the screw member 13.

  As described above, according to the present embodiment, the anchor reinforcement structure 1 can be obtained with a simple operation. Therefore, reinforcement of the existing column base 3 is easy. Moreover, since the anchor reinforcement structure 1 can prevent the anchor bolt 9 that fixes the column base 3 from being broken, the column base 3 can be prevented from falling.

  Further, after the earthquake, replacement can be easily performed by replacing the screw member 13.

  In addition, since the shaft portion 23 of the screw member 13 is plastically deformed, the design is easier than in the case of controlling the plastic deformation of the screw portion.

  In addition, by forming the screw member 13 by joining two members on the male screw portion side and the female screw portion side, the manufacture of each member is easy.

  Further, if the plastic deformation start load of the shaft portion 23 is larger than the load at which the threaded portion 9a of the anchor bolt 9 starts plastic deformation and smaller than the load at which the threaded portion 9a breaks, the anchor bolt 9 can be prevented from breaking. , High strength can be achieved at the same time.

  If the plastic deformation start load of the shaft portion 23 is smaller than the load at which the threaded portion 9a of the anchor bolt 9 starts plastic deformation, it is possible to prevent the threaded portion 9a of the anchor bolt 9 from being deformed after an earthquake.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1 ......... Anchor reinforcement structure 3 ......... Column base 5 ......... Floor 7 ......... Base plate 9 ......... Anchor bolt 9a ......... Screw part 11 ......... Reinforcement member 13 ......... Screw member 15 ... ... Fixing member 17 ......... Nuts 19 and 19a ......... Female threaded parts 21 and 21a ......... Male threaded parts 23 ......... Shaft part 25 ......... Hole 27 ......... Nut

Claims (7)

An anchor reinforcement structure,
Anchor bolts,
A reinforcing member attached to the top of the anchor bolt;
Comprising
The reinforcing member comprises a screw member and a fixing member capable of accommodating the screw member therein,
The screw member has a female screw portion formed at one end portion, a male screw portion formed at the other end portion, and a shaft portion between the female screw portion and the male screw portion,
The fixing member has a hole through which the male screw part and the shaft part can be inserted in one end part,
The shaft portion starts plastic deformation with a load smaller than the load at which the threaded portion of the anchor bolt breaks,
A gap is provided between the screw member and the fixing surface of the fixing member so that the female screw portion is connected to the anchor bolt and the screw member is covered with the fixing member. An anchor reinforcement structure, wherein the portion is fixed with a nut.   2. The anchor reinforcing structure according to claim 1, wherein the anchor bolt fixes a base plate of a column base.   3. The screw member according to claim 1, wherein the female screw portion, the shaft portion, and the male screw portion are configured separately, and the shaft portion and the female screw portion are joined. Anchor anchor structure described in 1.   The load at which the shaft portion starts plastic deformation is larger than the load at which the threaded portion of the anchor bolt starts plastic deformation, and smaller than the load at which the threaded portion breaks. 4. The anchor reinforcement structure according to any one of 3.   The anchor reinforcing structure according to any one of claims 1 to 3, wherein a load at which the shaft portion starts plastic deformation is smaller than a load at which the thread portion of the anchor bolt starts plastic deformation. A method for reinforcing an existing anchor,
Using an anchor reinforcement member comprising a screw member and a fixing member capable of accommodating the screw member therein,
Removing the nut of the anchor bolt;
Attaching the female thread portion formed at one end of the screw member to the anchor bolt;
The fixing member is covered with the screw member, and a male screw portion formed at the other end of the screw member and a shaft portion between the female screw portion and the male screw portion are provided in the fixing member. A process of passing through,
Fixing the male screw portion with a nut at the upper part of the fixing member in a state where the fixing member is covered on the screw member;
Comprising
There is a gap between the screw member and the fixing surface of the fixing member, and the shaft portion starts plastic deformation with a load smaller than a load at which the screw portion of the anchor bolt breaks. Anchor reinforcement method to do. An anchor reinforcement member,
A screw member;
A fixing member capable of accommodating the screw member therein;
Comprising
The screw member is formed at one end, and has a female screw portion connectable to an anchor bolt, a male screw portion formed at the other end, and a shaft portion between the female screw portion and the male screw portion. Have
The fixing member has a hole through which the male screw part and the shaft part can be inserted in one end part,
An anchor reinforcing member, wherein a diameter of the shaft portion is smaller than a diameter of a valley portion of the male screw portion.

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