JP2015025244A - Earthquake resistance strengthening structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earthquake resistance strengthening structure capable of dispensing with construction work of a lower floor of an earthquake resistance strengthening member, while transmitting stress between the earthquake resistance strengthening member and an existing frame, in the present invention.SOLUTION: The earthquake resistance strengthening structure 10 comprises the existing frame 12 and an earthquake resistance strengthening wall 50 provided in the existing frame 12. The existing frame 12 comprises a pair of columns 14, an upper side beam 16 and a lower side beam 18 installed on the pair of columns 14, A strengthening inverse beam 30 for supporting the earthquake resistance strengthening wall 50 is installed on the pair of columns 14. The strengthening inverse bram 30 is arranged on the upper side than a lower side existing slab 26 supported by a lower side beam 18, and a side part 30A1 of a side surface 30A is positioned outside in the surface outer direction of the existing frame 12 more than the lower side beam 18. Thus, the earthquake resistance strengthening wall 50 can be supported on the outside in the surface outer direction of the existing frame 12 more than the lower side beam 18.

Description

  The present invention relates to a seismic reinforcement structure.

  An existing wall reinforcing structure in which a reinforcing wall is provided separately from an existing wall in an existing RC structure is known (see, for example, Patent Document 1).

  Moreover, the earthquake-proof reinforcement structure which provided the steel frame brace with a frame in the existing frame made from RC is known (for example, refer patent document 2, 3).

JP 2010-127000 A JP 2004-238801 A JP 2008-014065 A

  By the way, it is desirable that seismic reinforcing members such as reinforcing walls and braces are joined to the lower beam constituting the existing frame so that stress can be transmitted by an anchor or the like.

  However, when the installation position of the seismic reinforcement member is shifted in the out-of-plane direction of the existing frame with respect to the lower beam, the thickness of the seismic reinforcement member (the length in the out-of-plane direction of the existing frame) is greater than the beam width of the lower beam. If the thickness is too thick, it becomes difficult to join the seismic reinforcing member to the lower beam by an anchor or the like so that sufficient stress can be transmitted.

  As a countermeasure, it is conceivable to increase the width of the beam by increasing the side of the lower beam, etc., but in this case, not only the installation floor of the seismic reinforcement member but also the lower floor, the construction will extend to the lower floor. May be restricted.

  In consideration of the above facts, the present invention provides a seismic reinforcement structure capable of transmitting stress between the seismic reinforcement member and the existing frame, while eliminating the need for work on the lower floor of the seismic reinforcement member. With the goal.

  The seismic reinforcement structure according to claim 1, an existing frame having a pair of columns, an upper beam and a lower beam installed on the pair of columns, an earthquake resistant reinforcement member provided on the existing frame, On the upper side of the existing slab supported by the lower beam, the pair of columns, the pair of intermediate columns provided on the existing frame, or the one of the pair of columns and the intermediate column provided on the existing frame In addition, at least a part is provided outside the lower beam in the out-of-plane direction of the existing frame, and includes a reinforcing reverse beam that supports the seismic reinforcement member.

  According to the seismic reinforcement structure according to the first aspect, the reinforced reverse beam that supports the seismic reinforcement member is disposed above the existing slab supported by the lower beam. This reinforced reverse beam is installed on either a pair of columns constituting the existing frame, a pair of intermediate columns provided on the existing frame, or a pair of columns and an intermediate column provided on the existing frame. By supporting the seismic reinforcing member by the reinforcing reverse beam, stress is transmitted between the seismic reinforcing member and the existing frame via the reinforcing reverse beam.

  Further, at least a part of the reinforcing reverse beam is positioned outside the lower frame in the out-of-plane direction of the existing frame. Therefore, when the seismic reinforcement member is installed at a position shifted to the outside in the out-of-plane direction of the existing frame with respect to the lower beam, the thickness of the seismic reinforcement member (the length of the existing frame in the out-of-plane direction) is lower Even if it is thicker than the beam width, the seismic reinforcing member can be supported by the reinforcing reverse beam.

  In addition, by supporting the seismic reinforcing member with the reinforcing reverse beam, it is possible to eliminate the need for extra striking on the lower beam. Therefore, it is possible to eliminate the work on the lower floor of the seismic reinforcement member.

  The seismic strengthening structure according to claim 2 is the seismic strengthening structure according to claim 1, wherein the reinforcing reverse beam is reinforced concrete, and the reinforcing reinforcing beam has a restraining bar for restraining the concrete in the axial direction. It is buried in.

  According to the seismic reinforcement structure according to the second aspect, the reinforcing bars are embedded in the direction of the material axis in the reinforced concrete reinforced reverse beam. By restraining the concrete of the reinforcing reverse beam with this restraint bar, it is possible to improve the stress transmission efficiency between the seismic reinforcement member and the existing frame as compared with the configuration without the restraint bar.

  The earthquake-proof reinforcement structure according to claim 3 is the earthquake-proof reinforcement structure according to claim 1 or 2, further comprising an existing wall provided on the existing frame, and the earthquake-proof reinforcement member is provided on one side of the existing wall. A seismic reinforcement wall provided across the upper beam and the reinforcing reverse beam.

  According to the earthquake-resistant reinforcement structure according to claim 3, the earthquake-resistant reinforcement member is an earthquake-resistant reinforcement wall provided on one side of the existing frame. In this case, the seismic reinforcement wall is likely to be shifted to the outside in the out-of-plane direction of the existing frame with respect to the lower beam. In such a case, the present invention is particularly effective, and the seismic reinforcing wall is supported between the seismic reinforcing wall and the existing frame by supporting the seismic reinforcing wall on the outer side in the out-of-plane direction of the existing frame by the reinforcing reverse beam. While making it possible to transmit stress, it is possible to eliminate the work on the lower floor of the seismic reinforcement wall.

  As described above, according to the earthquake-resistant reinforcement structure according to the present invention, it is possible to transmit stress between the earthquake-resistant reinforcement member and the existing frame, and to eliminate the work on the lower floor of the earthquake-resistant reinforcement member. .

It is an elevation view which shows the existing frame to which the seismic reinforcement structure concerning one Embodiment of this invention was applied. FIG. 2 is a sectional view taken along line 2-2 of FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. FIG. 4 is a sectional view taken along line 4-4 of FIG. (A) And (B) is sectional drawing corresponding to FIG. 2 which shows the modification of the earthquake-proof reinforcement structure which concerns on one Embodiment of this invention. It is an elevational view corresponding to FIG. 1 showing an existing frame to which the seismic reinforcement structure according to one embodiment of the present invention is applied. It is an elevational view corresponding to FIG. 1 showing an existing frame to which the seismic reinforcement structure according to one embodiment of the present invention is applied.

  Hereinafter, an earthquake-proof reinforcement structure according to an embodiment of the present invention will be described with reference to the drawings. In addition, the arrow R suitably shown in each figure has shown the out-of-plane direction of the existing frame.

  FIG. 1 shows an existing frame 12 to which the seismic reinforcement structure 10 according to this embodiment is applied. The existing frame 12 includes a pair of columns 14 and an upper beam 16 and a lower beam 18 that are installed on the pair of columns 14. The pair of columns 14, the upper beam 16, and the lower beam 18 are made of reinforced concrete (hereinafter referred to as “RC”). Further, an RC upper orthogonal beam 20 and a lower orthogonal beam 22 that are substantially orthogonal to the upper beam 16 and the lower beam 18 are joined to each column 14.

  An RC existing upper slab 24 is constructed on the upper beam 16 and the upper orthogonal beam 20, and an RC existing lower slab 26 is provided on the lower beam 18 and the lower orthogonal beam 22. Has been built. The upper existing slab 24 is supported by the upper beam 16 and the upper orthogonal beam 20, and the lower existing slab 26 as an existing slab is supported by the lower beam 18 and the lower orthogonal beam 22.

  As shown in FIG. 2, the existing frame 12 is provided with an RC existing wall 28. The existing wall 28 is arranged close to one side in the out-of-plane direction (arrow R direction) of the existing frame 12, and the back surface (surface opposite to the reinforcing reverse beam 30) 28 </ b> B is the side surface 14 </ b> B of the pair of columns 14. It is almost the same. The back surface 28B of the existing wall 28 and the side surfaces 14B of the pair of pillars 14 do not necessarily have to be substantially flush with each other, and a step may be formed between them.

  As described above, the existing frame 12 having the existing wall 28 is provided with the reinforcing reverse beam 30 and the earthquake-resistant reinforcing wall 50 at the time of the earthquake-proof repair. As shown in FIG. 1, the reinforcing reverse beam 30 is installed on the column bases of the pair of columns 14 on the upper side of the lower existing slab 26, and supports the seismic reinforcing wall 50. As shown in FIG. 2, the reinforcing reverse beam 30 is formed on the other side in the out-of-plane direction of the existing frame 12 along the surface 28 </ b> A of the existing wall 28 and the upper surface 26 </ b> A of the lower existing slab 26 (see FIG. 3). Is provided.

  A plurality of anchors 32 are embedded in opposite ends of the reinforcing reverse beam 30 in the material axis direction along reverse beam main bars 34 to be described later. The distal end portion of the anchor 32 extends into the column 14, and the both ends of the reinforced reverse beam 30 are joined to the pair of columns 14 so that stress (shearing force or the like) can be transmitted by the anchor 32. The side surface 30A of the reinforcing reverse beam 30 is substantially flush with the side surface 14A (see FIG. 2) of the pair of pillars 14. However, the side surface 30A of the reinforcing reverse beam 30 and the side surface 14A of the column 14 are not necessarily flush with each other, and a step may be formed between them.

  Further, as shown in FIG. 3, a plurality of reverse beam main bars 34 and a plurality of shear reinforcing bars 36 as constraint bars are embedded in the reinforcing reverse beam 30. The plurality of reverse beam main bars 34 are arranged along the material axis direction of the reinforcing reverse beam 30. The plurality of shear reinforcement bars 36 are arranged at intervals in the material axis direction of the reinforcing reverse beam 30 and surround the plurality of reverse beam main bars 34. By restraining the concrete at the center of the reinforced reverse beam 30 by these shear reinforcement bars 36, a stress transmission path is formed at the center of the reinforced reverse beam 30.

  Here, the existing wall 28 side of the reinforcing reverse beam 30 overlaps the lower beam 18 in the vertical direction in plan view. On the other hand, the side portion 30A1 of the reinforced reverse beam 30 on the side opposite to the existing wall 28 (side surface 30A side) is located on the outer side in the out-of-plane direction (the other side) of the existing frame 12 with respect to the lower beam 18. Thereby, the seismic reinforcement wall 50 can be supported on the outer side in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18. The reinforcing reverse beam 30 is joined to the lower beam 18, the lower existing slab 26, and the existing wall 28 by an anchor 38 so that stress can be transmitted. The anchor 38 can be omitted as appropriate. A plurality of beam main bars 40 and a plurality of shear reinforcement bars 42 are embedded in the lower beam 18 and the upper beam 16.

  As shown in FIGS. 3 and 4, the seismic reinforcing wall 50 is formed integrally with the reinforcing reverse beam 30 and is provided across the reinforcing reverse beam 30 and the upper beam 16. The surface 50A of the seismic reinforcement wall 50 is substantially flush with the side surface 30A of the reinforced reverse beam 30 so that the beam shape of the reinforced reverse beam 30 does not appear. Further, the surface layer portion 50A1 on the side opposite to the existing wall 28 (on the surface 50A side) of the seismic reinforcement wall 50 is outside the existing frame 12 in the out-of-plane direction with respect to the lower beam 18 in the same manner as the side portion 30A1 of the reinforcing reverse beam 30. Located on the other side.

  A crack-inducing joint may be formed on the surface 50A of the seismic reinforcing wall 50, but it is not necessary to form a crack-inducing joint on the side surface 30A of the reinforcing reverse beam 30. Therefore, the seismic reinforcing wall 50 and the reinforced reverse beam 30 may be distinguished from the appearance depending on the presence or absence of a crack-inducing joint. Further, a step or the like may be formed between the surface 50A of the earthquake-proof reinforcing wall 50 and the side surface 30A of the reinforcing reverse beam 30.

  A plurality of vertical wall bars 52 and a plurality of horizontal wall bars 54 are embedded in the seismic reinforcement wall 50. The lower ends of the plurality of vertical wall bars 52 extend into the inside of the reinforcing reverse beam 30, and the seismic reinforcing wall 50 and the reinforcing reverse beam 30 are joined by these vertical wall bars 52 so as to transmit stress.

  Further, as shown in FIG. 4, the upper part of the seismic reinforcing wall 50 is formed according to the beam type of the upper beam 16 and covers the lower surface 16L and the side surface 16A of the upper beam 16. The upper portion of the seismic reinforcement wall 50 is joined to the upper beam 16 by an anchor 56 so that stress can be transmitted. Further, the upper end portion 50U of the seismic reinforcement wall 50 that covers the side surface 16A of the upper beam 16 is formed by striking the upper beam 16 in an increased manner. The anchor 56 can be omitted as appropriate.

  A plurality of shear reinforcement bars 58 are embedded in the upper end portion 50 </ b> U of the seismic reinforcement wall 50, and a stress transmission path is formed inside as in the case of the reinforcing reverse beam 30. Although not shown, the upper end portion 50U of the seismic reinforcement wall 50 and the pair of columns 14 are joined to each other by an anchor so that stress can be transmitted, similarly to the reinforcing reverse beam 30. As a result, the upper end portion 50U of the seismic reinforcement wall 50 functions as a beam constructed between the pair of columns 14. The shear reinforcement 58 can be omitted as appropriate, and the upper end portion 50U of the seismic reinforcement wall 50 and the pair of columns 14 do not necessarily have to be joined by an anchor or the like.

  Next, the operation of this embodiment will be described.

  As shown in FIG. 3, the existing frame 12 is provided with an existing wall 28. On one side of the existing wall 28 (the other side in the out-of-plane direction of the existing frame 12), a seismic reinforcing wall 50 and a reinforcing reverse beam 30 are provided, and the existing frame 12 is formed by the seismic reinforcing wall 50 and the reinforcing reverse beam 30. Is seismically reinforced.

  Here, the surface layer portion 50A1 of the seismic reinforcement wall 50 is located on the outer side in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18, and the lower beam 18 does not exist therebelow. In such a case, the surface layer portion 50A1 of the seismic reinforcing wall 50 cannot be joined to the lower beam 18 by an anchor or the like, and the stress of the seismic reinforcing wall 50 may not be sufficiently transmitted to the lower beam 18. There is.

  As a countermeasure, it is conceivable to increase the width of the lower beam 18 by increasing the number of the lower beam 18 as indicated by a two-dot chain line. However, in this case, since the construction also extends to the lower floor of the lower existing slab 26, that is, the lower floor of the installation floor of the seismic reinforcement wall 50, the use of the lower floor is limited.

  On the other hand, in this embodiment, the reinforced reverse beam 30 is provided on the existing frame 12. The reinforcing reverse beam 30 is installed on the column leg portions of the pair of columns 14 on the upper side of the lower existing slab 26 supported by the lower beam 18. That is, the reinforcing reverse beam 30 is provided on the installation floor of the seismic reinforcing wall 50. By supporting the aseismic reinforcing wall 50 by the reinforced reverse beam 30, stress can be transmitted between the aseismic reinforcing wall 50 and the pair of columns 14 via the reinforced reverse beam 30 during an earthquake.

  In addition, by supporting the seismic reinforcing wall 50 by the reinforcing reverse beam 30, it is not necessary to reinforce the lower beam 18. Therefore, it is possible to eliminate the work on the lower floor of the installation floor of the seismic reinforcement wall 50.

  As described above, according to the seismic reinforcement structure 10 according to the present embodiment, it is possible to transmit stress between the seismic reinforcement wall 50 and the existing frame 12, and to eliminate the need for work on the lower floor of the seismic reinforcement wall. .

  A plurality of shear reinforcement bars 36 are embedded in the reinforcing reverse beam 30 in the material axis direction. By restraining the concrete in the central portion of the reinforced reverse beam 30 by these shear reinforcement bars 36, a stress transmission path is formed in the central portion of the reinforced reverse beam 30. Therefore, the transmission efficiency of the stress between the earthquake-proof reinforcement wall 50 and the pair of columns 14 at the time of an earthquake can be improved as compared with the configuration without the shear reinforcement bar 36.

  Further, the reinforcing reverse beam 30 is joined to the lower beam 18, the lower existing slab 26, and the existing wall 28 by an anchor 38. Therefore, stress can be transmitted from the seismic reinforcement wall 50 to the lower beam 18, the lower existing slab 26, and the existing wall 28 through the reinforcing reverse beam 30 during an earthquake.

  As shown in FIG. 4, in the present embodiment, a shear reinforcement bar 58 is embedded in the upper end portion 50 </ b> U of the earthquake-proof reinforcement wall 50. Further, the upper end portion 50U of the seismic reinforcement wall 50 is joined to the upper beam 16 by an anchor 56 so as to be able to transmit stress, and is joined to the pair of columns 14 so as to be able to transmit stress by an anchor (not shown). Therefore, stress can be transmitted between the seismic reinforcement wall 50 and the pair of columns 14 via the upper end 50U of the seismic reinforcement wall 50 and the upper beam 16 during an earthquake.

  Next, a modification of the above embodiment will be described.

  In the above-described embodiment, an example in which the reinforced reverse beam 30 fits between the pair of columns 14 has been described. For example, as illustrated in FIG. If the existing frame 12 is positioned on the outer side in the out-of-plane direction, the additional striking portion 60 is provided on the side surface 14A of the column 14, and stress can be transmitted to the additional striking portion 60 by the anchors 32 at both ends of the reinforcing reverse beam 30. You may join to. Note that the additional striking portion 60 is joined to the column 14 by an anchor 62.

  Moreover, although the example which provided the reinforcement reverse beam 30 and the earthquake-proof reinforcement wall 50 in the existing frame 12 which has the existing wall 28 was shown in the said embodiment, it is not restricted to this. For example, the reinforcing reverse beam 30 and the seismic reinforcing wall 50 may be provided on the existing frame 12 where the existing wall 28 does not exist.

  Further, for example, in the existing frame 12 where the existing wall 28 does not exist, the thickness of the seismic reinforcing wall 50 (the length of the existing frame 12 in the out-of-plane direction) is thicker than the lower beam 18, and the surface layers on both sides of the seismic reinforcing wall 50 When the portion is located on both sides in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18, the following may be performed.

  That is, as shown in FIG. 5B, the beam width of the reinforced reverse beam 70 is made wider than the beam width of the lower beam 18, and the sides of the reinforced reverse beam 70 on both sides (side surface 70A side and side surface 70B side). The parts 70A1 and 70B1 are positioned on the outer side in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18, respectively. As a result, even when the surface layer portions on both sides of the seismic reinforcing wall 50 are located on the outer side in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18 as described above, the seismic reinforcing wall 50 is supported by the reinforcing reverse beams 70. Can be supported.

  Further, the entire reinforcing reverse beam 30 can be positioned on the outer side in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18. That is, it is only necessary that at least a part (for example, the side portion 30A1) of the reinforced reverse beam 30 is located on the outer side in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18.

  Moreover, in the said embodiment, although the example which embed | buried the shear reinforcement bar | burr 36 as a restraint bar | burr in the reinforcement reverse beam 30 was shown, it does not restrict to this. As the restraint muscle, for example, a loop muscle or a spiral spiral muscle may be used.

  Moreover, in the said embodiment, although the example which constructed the reinforcement reverse beam 30 on a pair of pillar 14 was shown, it is not restricted to this. For example, as shown in FIG. 6, at the time of seismic retrofit, a pair of intermediate columns 72 may be provided on the existing frame 12, and the reinforcing reverse beam 30 may be installed on the pair of intermediate columns 72. Although not shown, the reinforcing reverse beam 30 can be installed between any one of the pair of columns 14 and the intermediate column 72 provided on the existing frame 12.

  Moreover, in the said embodiment, although the example which joined the earthquake-proof reinforcement wall 50 to the existing wall 28 was shown, it is not restricted to this. For example, the existing wall 28 and the seismic reinforcement wall 50 may be separated from each other without being joined. Furthermore, the existing wall 28 and the seismic reinforcement wall 50 are not limited to RC structures, but may be a steel seismic wall formed of, for example, a steel plate.

  Furthermore, the seismic reinforcing member is not limited to the seismic reinforcing wall 50, and braces or the like may be used. Further, the reinforcing reverse beam 30 is not limited to the RC structure, and may be a steel concrete structure or a steel structure. For example, the existing frame 12 shown in FIG. 7 is provided with a pair of steel braces 80 as seismic reinforcement members and a steel-reinforced reinforcing reverse beam 86.

  The pair of steel braces 80 are formed of H-shaped steel or the like, and their upper ends are joined to the upper beam 16 via gusset plates 82. On the other hand, the lower end portions of the pair of steel braces 80 are joined to the central portion of the reinforcing reverse beam 86 in the material axis direction via a bracket 84.

  The reinforcing reverse beam 86 is formed of H-shaped steel and is disposed along the upper surface of the lower existing slab 26. End plates 90 with a plurality of studs 88 projecting are provided at both ends of the reinforcing reverse beam 30. By embedding these studs 88 in the column bases of the pair of columns 14, the reinforced reverse beam 86 is installed on the column bases of the pair of columns 14. Although not shown, one side portion of the reinforcing reverse beam 86 is located on the outer side in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18. As a result, the pair of steel braces 80 can be supported on the outer side in the out-of-plane direction of the existing frame 12 with respect to the lower beam 18. The reinforcing reverse beam 86 may be joined to the lower existing slab 26.

  Furthermore, the pair of pillars 14, the upper beam 16, and the lower beam 18 constituting the existing frame 12 are not limited to the RC structure, but may be a steel concrete structure or a steel structure.

  As mentioned above, although one embodiment of the present invention was described, the present invention is not limited to such an embodiment, and one embodiment and various modifications may be used in combination as appropriate, and the gist of the present invention will be described. Of course, various embodiments can be implemented without departing from the scope.

10 Seismic reinforcement structure 12 Existing frame 14 Column 16 Upper beam 18 Lower beam 26 Lower existing slab (existing slab)
28 Existing Wall 30 Reinforced Reverse Beam 30A1 Side (Part of Reinforced Reverse Beam)
36 Shear reinforcement (restraint)
50 Seismic reinforcement wall (seismic reinforcement member)
70 Side of reinforced reverse beam 70A1 (part of reinforced reverse beam)
70B1 side (part of reinforced reverse beam)
72 Spacer 80 Steel brace (seismic reinforcement member)
86 Reinforced reverse beam

Claims (3)

An existing frame having a pair of columns and an upper beam and a lower beam installed on the pair of columns;
A seismic reinforcement member provided in the existing frame;
On the upper side of the existing slab supported by the lower beam, the pair of columns, the pair of intermediate columns provided on the existing frame, or the one of the pair of columns and the intermediate column provided on the existing frame And at least a part of the reinforced reverse beam that is located on the outside of the existing frame in the out-of-plane direction with respect to the lower beam and supports the seismic reinforcement member,
Seismic reinforcement structure with The reinforcing reverse beam is a reinforced concrete structure, and the reinforcing reverse beam has a constraining bar that constrains the concrete embedded in the material axis direction.
The earthquake-proof reinforcement structure according to claim 1. Including an existing wall provided in the existing frame;
The seismic reinforcing member is a seismic reinforcing wall provided on one side of the existing wall across the upper beam and the reinforcing reverse beam.
The earthquake-proof reinforcement structure according to claim 1 or 2.

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