JP2010150793A - Anchor for seismic strengthening and seismic strengthening structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anchor for seismic strengthening, capable of increasing a seismic strengthening performance and a seismic strengthening structure using the anchor. <P>SOLUTION: A fixed shaft part 2 on which a male screw 6 is formed at least partly and which is screwed and fixed in a hole drilled in an existing structure through the male screw, and a fixing shaft part 3 which is formed of a material having a lower strength than the material of the fixed shaft and buried in a newly installed structure or an extended structure are formed integrally with each other. The strength of the fixing shaft is substantially equal to the strength of the fixed body provided to the extended structure and the strength of the reinforcements disposed in the newly installed structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a seismic reinforcement anchor capable of improving seismic reinforcement performance and a seismic reinforcement structure using the anchor.

  In recent years, in order to improve the earthquake resistance performance of existing RC structures and SRC structures, earthquake-resistant reinforcement work such as newly installing earthquake-resistant walls or adding steel frames such as steel braces and RC frames has become popular. Has been done.

  In these seismic reinforcement constructions, seismic reinforcement anchors are generally used. RC that drills holes at predetermined positions of existing structures such as columns and beams, fixes one end of the seismic reinforcement anchor to the hole, and installs or extends the other end protruding from the existing structure Concrete or mortar or the like is placed as a fixing portion of a structural body such as a frame or a steel frame, and the fixing portion is embedded.

  Of these types of seismic reinforcement anchors, the following are known as anchors that are inserted into a drilling hole and fixed by some fixing means.

  (1) An anchor fixed by a resin-based or cement-based adhesive material filled in a hole (see Patent Document 1).

  (2) An anchor that is fixed by providing an expansion portion on a sleeve provided at the end of a reinforcing bar or a sleeve formed with a male screw, and expanding the expansion portion within the hole so as to bite into the hole wall (Patent Documents 2 and 2) 4).

  The fixing means in this type of seismic reinforcement anchor is also used for a fixing anchor for fixing equipment or the like to the ground or ceiling. This type of anchor has some advantages and disadvantages in terms of performance and construction, but is intended to be fixed, so it can be fixed so that the target equipment does not collapse or fall. It is only necessary to have a proof strength that can counteract the tensile force and pure shear force of.

  On the other hand, an anchor for seismic reinforcement is required to have a performance capable of integrating an existing structure and a structure such as a newly-installed or additional RC frame. In other words, in order to embed the anchor inside the existing structure and the structure to be newly added or added, not only the tensile force and shearing force but also various forces such as compression, bending, and twisting act on the anchor. become. For this reason, the conventional seismic reinforcement anchor has the following problems.

  (B) Although it functions effectively with respect to tensile force and shear force, its effectiveness is low with respect to forces such as bending and bending tension. Moreover, since the inner diameter of the hole drilled in the existing structure is larger than the outer diameter of the anchor in construction, the gap between the anchor and the inner surface of the hole causes a gap between the anchor and the existing structure. It is difficult to reliably transmit the bending force.

  (B) With anchors that are fixed with adhesive material, the performance of the adhesive material depends on the weather conditions during construction and the concrete chips generated during drilling. In some cases, the prescribed performance is not satisfied. Also, as the outer diameter of the anchor becomes larger, the length becomes longer, and the inner diameter of the hole also becomes larger, which necessitates the formation of a long and large hole. Since the gap between the two becomes large, the workability is deteriorated, for example, it takes time for the fixing work with the adhesive material.

  (C) The type of anchor that is fixed by the expansion action is a mechanism for fixing the expanded portion by biting into the pit wall, so that it is weak to a force other than the drawing direction and is inferior in yield strength as an anchor. In addition, as the outer diameter of the anchor becomes larger, there is a problem that the operation of driving the sleeve into the hole and the operation of expanding the expansion portion in the hole become difficult and large.

  As described above, there are various problems in the conventional earthquake-proof reinforcement anchor that is inserted into the drilling hole and fixed with an adhesive material or an extended portion, and when such an anchor is used for the earthquake-proof reinforcement structure. The degree of fixing with respect to the existing structure is lower than the degree of fixing with respect to the newly installed or added structure. For this reason, when various forces act on the structure in which the existing structure and the newly installed or added structure are integrated, there is a possibility that the boundary surface between the structures is displaced and cracks are generated.

  In addition, since a large number of anchors must be hit on an existing structure with a low degree of fixation, the number of drilling holes increases, which causes problems in terms of seismic reinforcement performance, work, and environment.

On the other hand, in the above-mentioned anchor for fixing, there is also known one that can be screwed directly into a drilling hole by forming a male screw as a fixing means (see Patent Documents 5 to 6). This screw-type anchor has a minimum hole inner diameter, and since it is fixed with a screw, it has excellent features such as being able to obtain stable strength regardless of weather conditions and construction conditions. Have.
JP 2004-116128 A Japanese Patent No. 2911036 Japanese Patent Laid-Open No. 9-195523 Japanese Patent Laid-Open No. 9-279856 JP 2004-19370 A Japanese Patent Laid-Open No. 2004-27640 Utility Model Registration No. 3087932

  When integrating an existing structure with an additional structure, or when constructing and integrating a new structure with an existing structure, the former is a filler such as concrete or mortar between the structures. In the latter case, concrete of a new structure is placed. The seismic reinforcement anchor provided on the existing structure or the anchor attached to the seismic reinforcement anchor and the additional structure is embedded in concrete or a filler so as to integrate these structures.

  Here, when using as a seismic reinforcement anchor by extending the screw-type fixing anchor to a length that can be embedded and anchored in concrete or filler, the conventional screw-type fixing anchor is Since the male screw is screwed into the hole drilled in the concrete, heat-treated materials or materials that are extremely hard and have little elongation are used so that the screw parts are not consumed or crushed. Therefore, for example, the balance between the strength of the extended portion embedded in the filler of the screw-type fixing anchor and the strength of the fixing body does not match and the strength becomes considerably biased.

  As a result, if various forces act on a structure that integrates an existing structure with a new structure, etc., the boundary surface of these structures will be displaced, causing cracks, leading to performance degradation. There was a fear that it could not be used as an anchor for seismic reinforcement.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide an earthquake-resistant reinforcement anchor capable of improving the earthquake-proof reinforcement performance and an earthquake-proof reinforcement structure using the anchor.

  The anchor for seismic reinforcement according to the present invention includes a fixed shaft portion that has a male screw formed at least in part and is screwed into a hole drilled in an existing structure via the male screw, and the fixed shaft portion. The fixing shaft portion is formed of a material having a lower strength than the above-described material, and is integrally formed with a fixing shaft portion embedded in a new or additional structure.

  The earthquake-proof reinforcement structure according to the present invention is an earthquake-proof reinforcement structure using the above-mentioned earthquake-proof reinforcement anchor, and the strength of the fixing shaft portion is substantially the same as the strength of the fixing body provided in the structure to be added. Features.

  The seismic reinforcement structure according to the present invention is a seismic reinforcement structure using the above-mentioned seismic reinforcement anchor, and the strength of the anchoring shaft portion is substantially the same as the strength of the reinforcing bars arranged in the newly installed structure. It is characterized by.

  In the earthquake-proof reinforcement anchor and the earthquake-proof reinforcement structure using the same according to the present invention, the earthquake-proof reinforcement performance can be improved.

  BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a seismic reinforcement anchor according to the present invention and a seismic reinforcement structure using the same will be described in detail with reference to the accompanying drawings. FIG. 1 shows a front view of an anchor 1 for seismic reinforcement according to the present embodiment.

  As shown in the drawing, the seismic reinforcement anchor 1 according to the present embodiment is formed in a shaft shape as a whole. In the figure, the anchor 1 for seismic reinforcement is formed with a lower portion as a fixed shaft portion 2 and an upper portion with a fixing shaft portion 3. A screw-headed bolt head 4 is integrally attached to the upper end of the fixed shaft portion 2 so as to be positioned between the fixing shaft portion 3 and the fixing shaft portion 3. A screw portion 5 to be screwed into the screw hole of the bolt head 4 is formed at the lower end portion of the fixing shaft portion 3, and the fixing shaft portion 3 and the fixed shaft portion 2 are integrated by screwing the screw portion 5 into the screw hole. Is done.

  A male screw 6 is formed in the fixed shaft portion 2 along the axial direction. The male screw 6 is screwed into a hole drilled in the existing structure. The effective diameter of the male screw 6 is set slightly larger than the hole diameter. The length of the male screw 6 only needs to have at least a length that can be reliably fixed to the existing structure, and the length of the fixed shaft portion 2 is set to be approximately the same as or slightly shorter than the length of the hole. Is done. Therefore, when the fixed shaft portion 2 is screwed into the hole, the bolt head 4 is substantially in contact with the surface of the existing structure.

  The fixing shaft portion 3 is formed of a deformed steel bar 6 such as a deformed reinforcing bar having a vertical rib, an annular rib, and a threaded rib. For example, the fixing shaft portion 3 may be formed by forming a screw portion at the end of the deformed reinforcing bar. The fixing shaft portion 3 may be formed with a flange portion 7 at the upper end opposite to the screw portion 5 as shown by an imaginary line in FIG. The outer contour of the flange 7 is formed in a polygonal shape such as a hexagon, for example, so that the seismic reinforcement anchor 1 can be rotated and screwed with a bolt fastener. Further, the flange 7 is embedded in a filler such as concrete or mortar filled between the existing structure and the additional structure, or in the concrete of the new structure to fix the fixing shaft 3. Increase action.

  In particular, the material of the fixing shaft 3 is set to be lower in strength than the material of the fixed shaft 2. Since the fixed shaft portion 2 needs to be screwed into the concrete of the existing structure, a high strength material with high hardness and low elongation is selected. On the other hand, in order to efficiently and effectively transmit the force acting on the seismic reinforcement structure, the fixing shaft portion 3 is adapted to the material of the fixing body attached to the structure such as an extension, and is subjected to tension / compression and bending performance. A low-strength material rich in torsional performance is selected.

  For example, the fixed shaft portion 2 is made of boron steel (steel for hard striking) containing boron in steel or carbon steel for machine structure (S45C or the like) subjected to heat treatment. On the other hand, the fixing shaft portion 3 is made of aluminum killed steel or silicon killed steel used for stud bolts, or steel bars for reinforced concrete (such as SD345 and SD390).

  In the seismic reinforcement anchor 1 having such a configuration, the fixed shaft portion 2 is such that the male screw 6 is screwed into a hole drilled in the concrete, but the male screw 6 is consumed or crushed. Without fail, a reliable fixing action is obtained. Further, the strength of the fixing shaft portion 3 embedded in the filler or the concrete of the new structure can be balanced with the strength of the fixing body provided in the additional or new structure.

  Moreover, since the anchor 1 for seismic reinforcement according to the present embodiment is formed integrally with the fixed shaft portion 2 and the fixing shaft portion 3 via the bolt head 4 joined by friction welding, the fixed shaft portion 2 and fixing shaft part 3 are secured, while the fixed shaft part 2 and the fixing shaft part 3 having these different functions can be handled as a single seismic reinforcement anchor 1 to complete the mounting. Excellent and can be constructed with high workability.

  FIG. 2 shows a front cross-sectional view of an example of a seismic reinforcement structure to which the seismic reinforcement anchor 1 shown in FIG. 1 is applied. In the illustrated example, a pair of left and right vertical frames 9 arranged facing the existing pillar 8, an upper frame 11 arranged facing the existing beam 10, and a lower frame (not shown) arranged on the existing floor are shown. The RC or SRC existing structure 15 is seismically reinforced by a steel frame 14 which is connected to the gusset plate 12 and provided with braces 13 in a rectangular frame structure in which the frame is joined by the gusset plate 12. It is a thing.

  A plurality of stud bolts 16 serving as fixing bodies are provided on the frames 9 and 11 of the steel frame 14 so as to protrude from the frames 9 and 11 toward the existing columns 8 and the existing beams 10. As the stud bolt 16, a generally well-known one such as a round steel bar with a head or a deformed steel bar is used. The stat bolt 16 is set to have substantially the same strength as the fixing shaft portion 3 of the anchor 1 for seismic reinforcement. In other words, the fixing shaft portion 3 of the earthquake-proof reinforcement anchor 1 is set to have substantially the same strength as the stat bolt 16. For example, the fixing shaft portion 3 and the stat bolt 16 of the seismic reinforcement anchor 1 are made of the same material. When the stud bolt 16 is a deformed steel bar, it is preferable that the fixing shaft part 3 of the anchor 1 for seismic reinforcement is also a deformed steel bar.

  On the other hand, a plurality of the earthquake-proof reinforcing anchors 1 are attached to the existing structure 15 while being shifted from the attachment position of the stat bolt 16.

  The attachment of the seismic reinforcement anchor 1 will be described. A hole is drilled by a drill from the surface of the existing structure 15, for example, the existing pillar 8 or the existing beam 10. In addition, the screw portion 5 of the fixing shaft portion 3 is screwed into the screw hole of the bolt head 4 of the fixed shaft portion 2 in advance to form an integrated earthquake-proof reinforcement anchor 1.

  Next, the fixed shaft portion 2 is screwed into the hole and screwed to such an extent that the bolt head 4 comes into contact with the surface of the existing column 8 or the like. The fixed shaft portion 2 is screwed by gripping and rotating the collar portion 7 with a bolt fastener. As a result, the earthquake-proof reinforcing anchor 1 is attached to the existing structure 15.

  Thereafter, a filler 17 such as concrete or mortar is filled between the existing structure 15 and the frames 9 and 11 of the steel frame 14 to be added and solidified. Thereby, the seismic reinforcement structure in which the steel frame 14 is added to the existing structure 15 is completed.

  In addition, before screwing the fixed shaft portion 2 into the hole, the hole may be filled with a resin-based or cement-based adhesive material in advance, thereby further increasing the degree of fixing to the existing structure 15. it can.

  The anchor 1 for seismic reinforcement shown in FIG. 1 has a male screw 6 formed at least in part, and is fixed by being screwed into a hole drilled in an existing structure 15 via the male screw 6. And the fixing shaft portion 3 which is formed of a material having a lower strength than the material of the fixed shaft portion 2 and embedded in the filler 17 at the time of expansion. Can be properly fixed to the existing structure 15 made of RC as before, and the fixing shaft portion 3 is made of a material having a lower strength than the fixed shaft portion 2, so that it can be added to the existing structure 15. Various forces act on the structure composed of the steel frame 14, and various forces such as compression, tension, bending and twisting are applied to the anchoring shaft portion 3 of the earthquake-proof reinforcement anchor 1 embedded in the filler 17. Even if it acts, the fixing shaft 3 does not break easily, It can be properly transmitted received.

  In addition, since the strength of the fixing shaft 3 is set to be substantially the same as the strength of the stud bolt 16 provided in the steel frame 14 to be added, the stud bolt 16 and the fixing shaft 3 which are stress transmission elements in the filler 17 are provided. Can be balanced between the existing structure 15 side and the additional steel frame 14 side, and various forces act on the seismic reinforcement structure that integrates the existing structure 15 and the additional steel frame 14. However, it is possible to prevent the occurrence of displacement at the boundary surfaces of the structures 14 and 15 and to prevent the occurrence of structural deterioration such as cracks, thereby enhancing the performance of the seismic reinforcement structure.

  In the present embodiment, the flange portion 7 of the fixing shaft portion 3 is gripped with a bolt fastener, and the seismic reinforcement anchor 1 is screwed in, so that the bolt fastener is attached to the surface of the existing column 8 or the like when screwing. Work can be performed smoothly without interference. When the flange portion 7 is not provided, the deformed steel bar 6 portion of the fixing shaft portion 3 may be gripped with a chuck of a bolt fastener or the like and screwed.

  FIG. 3 shows a cross-sectional plan view of another example of the seismic reinforcement structure to which the seismic reinforcement anchor 1 shown in FIG. 1 is applied. In the figure, the lower part shows a cross section at the position of the existing RC beam 10 and the upper part shows a cross section at the position of the newly installed RC earthquake-resistant wall 18. Moreover, in FIG. 3, the anchor 1 for earthquake-proof reinforcement which does not provide the collar part 7 is shown.

  In the illustrated example, the existing structure 15 is seismically reinforced by newly installing a seismic wall 18 on the existing column 8 made of RC. A wall reinforcing bar 20 around which a shear reinforcing bar 19 is wound is embedded in the newly installed earthquake resistant wall 18. The wall reinforcing bar 20 is set to have substantially the same strength as that of the fixing shaft portion 3 of the anchor 1 for seismic reinforcement. In other words, the fixing shaft 3 of the anchor 1 for seismic reinforcement is set to have substantially the same strength as the wall reinforcing bar 20. For example, the fixing shaft portion 3 and the wall reinforcing bars 20 of the seismic reinforcement anchor 1 are made of the same material.

  On the other hand, a plurality of the above-mentioned seismic reinforcement anchors 1 are attached to the existing pillar 8 of the existing structure 15 so as to form a wall joint 20 and a lap joint. Of course, the seismic reinforcement anchor 1 may be disposed with a position shifted from the wall reinforcing bar 20, or may be directly connected to the wall reinforcing bar 20 via a coupler or the like.

  The attachment of the seismic reinforcement anchor 1 is the same as in FIG. The screw portion 5 of the fixing shaft portion 3 is screwed into the screw hole of the bolt head 4 of the fixed shaft portion 2 to prepare in advance as an integral earthquake-proof reinforcement anchor 1. The seismic reinforcement anchor 1 without the flange 7 is screwed by gripping and rotating the deformed steel bar 6 with a bolt fastener.

  After the seismic reinforcement anchor 1 is attached to the existing column 8, concrete 21 for constructing a new seismic wall 18 is placed, and the wall rebar 20 and the anchoring shaft portion 3 of the seismic reinforcement anchor 1 are embedded therein. Solidify. Thereby, the seismic reinforcement structure in which the seismic wall 18 is newly installed in the existing structure 15 is completed.

  Even in application to the newly installed seismic wall 18, the anchor 1 for seismic reinforcement can be appropriately fixed to the existing structure 15 made of RC as before, with respect to the fixed shaft portion 2 as described above. In addition, the anchoring shaft portion 3 of the seismic reinforcement anchor 1 embedded in the cast concrete 21 is subjected to various forces acting on the structure composed of the existing structure 15 and the newly installed seismic wall 18 to compress or Even if various forces such as tension, bending, and twisting are applied, these forces can be received and properly transmitted without being easily broken.

  Further, since the strength of the fixing shaft 3 is set to be substantially the same as the strength of the wall reinforcing bar 20 provided on the newly installed earthquake-resistant wall 18, these wall reinforcing bars 20 and fixing shafts which are stress transmission elements in the cast concrete 21 are set. 3 can be balanced between the existing structure 15 side and the newly installed earthquake-resistant wall 18 side, and various forces act on the structure in which the existing structure 15 and the newly installed earthquake-resistant wall 18 are integrated. However, it is possible to prevent the occurrence of displacement at the boundary surfaces of the structural bodies 15 and 18 and to prevent the occurrence of structural deterioration such as cracks, thereby improving the performance of the seismic reinforcement structure.

  In the present embodiment, the fixing shaft portion 3 is gripped by the bolt fastener and the seismic reinforcement anchor 1 is screwed in, so that the bolt fastener may interfere with the surface of the existing column 8 when screwed. And can work smoothly.

  4 to 6 show modifications of the seismic reinforcement anchor according to the present invention. The anchor 1 for seismic reinforcement shown in FIG. 4 is obtained by omitting the bolt head 4 with screw holes and the screw portion 5, and the fixed shaft portion 2 and the fixing shaft portion 3 are joined together in series by friction welding or the like. Is. The fixing shaft portion 3 is formed in a solid shaft shape. When screwing, the fixing shaft portion 3 may be gripped with a chuck of a bolt fastener.

  In addition to the seismic reinforcement anchor 1 shown in FIG. 4, the one shown in FIG. 5 is positioned at the boundary position between the fixed shaft portion 2 and the fixing shaft portion 3, and is a ring for abutting against an existing structure. A portion 22 is integrally provided, and a flange portion 7 similar to that shown in FIG. 1 is provided at the upper end of the fixing shaft portion 3.

  6, the anchor 1 for seismic reinforcement shown in FIG. 5 is replaced by a fixing shaft 3 of deformed steel bar 6 instead of a solid fixing shaft, and the flange 7 is used as the fixing shaft 3. The upper and lower nuts that are screwed to the threaded portion formed at the upper end of the upper and lower fixing plates sandwiched between the nuts.

  Even in these modifications, the same effects as the earthquake-resistant reinforcement anchor 1 described in the above embodiment can be obtained, and these earthquake-resistant reinforcement anchors 1 can be applied to an earthquake-resistant reinforcement structure with a newly installed structure or an additional structure. Of course, the same effects as described above can be obtained.

It is a front view which shows suitable one Embodiment of the anchor for seismic reinforcement concerning this invention. It is principal part front sectional drawing which shows suitable one Embodiment of the earthquake-proof reinforcement structure concerning this invention. It is principal part plane sectional drawing which shows other embodiment of the earthquake-proof reinforcement structure concerning this invention. It is a front view which shows the modification of the anchor for earthquake resistance reinforcement shown in FIG. It is a front view which shows the other modification of the anchor for seismic reinforcement shown in FIG. It is a front view which shows the further another modification of the anchor for seismic reinforcement shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anchor for earthquake-proof reinforcement 2 Fixed shaft part 3 Fixing shaft part 6 Male screw 14 Steel frame 15 Existing structure 16 Stud bolt 18 Seismic wall 20 Wall reinforcement

Claims (3)

  A male screw is formed at least in part, and is formed of a fixed shaft portion that is fixed by being screwed into the hole formed in the existing structure via the male screw, and a material that is lower in strength than the material of the fixed shaft portion. An anchor for seismic reinforcement characterized by integrally forming a fixing shaft portion embedded in a structure to be newly installed or added.   A seismic reinforcement structure using the seismic reinforcement anchor according to claim 1, wherein the strength of the fixing shaft portion is substantially the same as the strength of a fixing body provided in a structure to be added. Reinforced structure.   A seismic reinforcement structure using the seismic reinforcement anchor according to claim 1, wherein the strength of the fixing shaft portion is substantially the same as the strength of a reinforcing bar arranged in a newly installed structure. Seismic reinforcement structure.

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