JP2010189925A - Seismic strengthening structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seismic strengthening structure which can omit or reduce a post-installed anchor interposed between an existing frame and an additional one. <P>SOLUTION: Characteristically, this seismic strengthening structure includes a precast concrete column 1 and a precast concrete beam 2; the precast concrete column 1 comprises a column body 11 which is arranged along the front of an existing column P, and an overhang portion 12 which overhangs in a lateral direction from the column body portion 11; the precast concrete beam 2 comprises a beam body 21 which is arranged along the front face of an existing beam B, and a joint end 22 which overlaps the rear side of the overhang portion 12; and a tendon 3, to which a tensile force is applied, is provided through the overhang portion 12, the joint end 22 and the existing beam B, so that the column body 11 can be pressure-bonded to the front face of the existing column P. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a seismic reinforcement structure installed in an existing building.

As an earthquake-proof reinforcement structure for an existing building, for example, one disclosed in Patent Document 1 is known.
The earthquake-proof reinforcement structure of Patent Document 1 is to add a concrete reinforcement frame in front of an existing frame (such as a column or a beam). In the seismic reinforcement structure of Patent Document 1, the reinforcement frame is fixed to the front surface of the existing frame by using a post-installed anchor planted on the front surface of the existing frame. Depends on the shear strength of the post-installed anchor.

JP 2008-50788 A

  In order to improve the reinforcement efficiency in the earthquake-proof reinforcement structure of Patent Document 1, it is necessary to plant a large number of post-construction anchors. Therefore, as the number of post-installed anchors increases, the discomfort given to the building user may increase.

  From such a viewpoint, an object of the present invention is to provide a seismic reinforcement structure capable of omitting or reducing a post-installed anchor interposed between an existing frame and an additional frame.

  The present invention that solves such a problem is an earthquake-proof reinforcement structure including a PCa column and a PCa beam, and the PCa column includes a column main body disposed along a front surface of an existing column, and the column main body. The PCa beam is overlapped with a beam main body portion arranged along the front surface of the existing beam and the front side or the rear side of the overhanging portion. The column main body portion is pressure-bonded to the front surface of the existing column by applying a tensile force to the tension member penetrating the overhanging portion, the bonding end portion, and the existing beam. It is characterized by.

  In short, according to the present invention, the PCa column is pressure-bonded to the existing frame by penetrating a tension material through the overhanging portion of the PCa column, the joint end of the PCa beam, and the existing beam. According to the present invention, the shearing force at the time of earthquake acting on the existing frame is transmitted to the additional frame (PCa column and PCa beam) via the frictional force (crimping force) acting between the PCa column and the existing frame. Therefore, it becomes possible to omit or reduce the post-construction anchor which is a shear transmission member. Further, according to the present invention, it is possible to reinforce an existing frame without adding a beam or a slab made of cast-in-place concrete. Note that the beam main body may be pressure-bonded to the front surface of the existing beam, or may be arranged with a gap between the front surface of the existing beam.

  In ordinary beam-column frames, stress tends to concentrate at the beam-column joints (panel zones). In a beam-frame frame made of reinforced concrete, many reinforcing bars are arranged at the beam-column joints. Therefore, it is necessary to carefully drill holes and post-installed anchors in the beam-column joint. In the present invention, a tension material is provided at a position avoiding the panel zone (column-beam joint). Therefore, it is possible to avoid drilling or the like in the beam-column joint that is structurally important.

  The PCa column may be provided with a support portion that protrudes laterally from the column main body, and the joint end portion of the PCa beam may be placed on the upper surface of the support portion. In this way, the PCa beam can be supported on the PCa column even before the tensile force is applied to the tendon, so that the support work for temporarily supporting the PCa beam can be omitted or reduced. It becomes possible.

  When the joint end portion of the PCa beam is overlapped on the rear side of the overhanging portion, the end surface of the joint end portion may be abutted against the side surface of the PCa column and the side surface of the existing column. If it does in this way, since a part of shear force at the time of the earthquake which acted on the existing frame will be transmitted directly to a PCa beam, it will become possible to reduce the load concerning a tension material.

  According to the present invention, since it becomes possible to reduce the number of shear transmission members interposed between the existing frame and the additional column beam frame, for example, when performing seismic reinforcement while continuing to use the building, It is possible to alleviate discomfort given to building users.

It is a perspective view which shows the earthquake-proof reinforcement structure which concerns on embodiment of this invention. It is a horizontal sectional view of an earthquake-proof reinforcement structure concerning an embodiment of the present invention. It is a vertical sectional view (XX sectional view taken on the line in FIG. 2) of the seismic reinforcement structure according to the embodiment of the present invention. It is a disassembled perspective view which shows the earthquake-proof reinforcement structure which concerns on embodiment of this invention. It is a horizontal sectional view showing a modification of an earthquake-proof reinforcement structure concerning an embodiment of the present invention. It is a vertical sectional view showing another modification of the earthquake-proof reinforcement structure concerning the embodiment of the present invention.

  As shown in FIG. 1, the seismic reinforcement structure according to the embodiment is applied to an existing frame in which the front surface (outer surface) of the existing column P is positioned in front of the front surface (outer surface) of the existing beam B. In the following description, the outdoor side of the existing building is referred to as “front side”, and the indoor side of the existing building is referred to as “rear side”.

  The existing pillar P and the existing beam B, which are subject to seismic reinforcement, have a reinforced concrete structure. The existing beam B exemplified in the present embodiment is a so-called wall girder, but is not intended to limit the form of the existing beam B.

  The seismic reinforcement structure according to the present embodiment penetrates the PCa column 1 arranged in the vertical direction, the PCa beam 2 arranged in a direction intersecting the PCa column 1, the PCa column 1, the PCa beam 2, and the existing beam B. It is provided with tension members 3, 3,.

  The PCa pillar 1 is made of a precast concrete member (PCa member). The PCa pillar 1 of the present embodiment includes a pillar main body portion 11 arranged along the front surface of the existing pillar P, an overhanging portion 12 projecting sideways from the pillar main body portion 11, and the column main body portion 11. And a support portion 13 projecting sideways. The overhang portion 12 and the support portion 13 are provided on both sides of the column main body portion 11.

  The column main body 11 is located on the front side of the existing column P and is crimped to the front surface of the existing column P. As shown in FIG. 2, the width dimension of the column main body 11 is the same as the width dimension of the existing column P. In the present embodiment, the rear surface 11r of the column main body 11 is brought into contact with the front surface Pf of the existing column P. However, a filler (such as non-shrinking mortar or epoxy resin) is provided between the column main unit 11 and the existing column P. Can be interposed.

  The overhang portion 12 is a portion that is overlapped with the PCa beam 2. As shown in FIG. 1, in the present embodiment, a total of four overhanging portions 12, 12,... Are provided corresponding to the four PCa beams 2, 2,. Yes. It should be noted that the plurality of overhang portions 12, 12,... Are desirably arranged in a well-balanced manner (for example, symmetrically) so that an uneven load does not act on the column main body portion 11, but depending on the current state of the existing frame, etc. It may be changed appropriately.

  The overhang portion 12 is a reinforced concrete corbel (cantilever with a short span) that has a rectangular shape when viewed from the front, and is formed integrally with the column main body portion 11. The upper and lower surfaces of the overhang portion 12 are flush with the upper and lower surfaces of the PCa beam 2, and the front surface of the overhang portion 12 is flush with the front surface of the column main body portion 11. As shown in FIG. 2, the overhanging portion 12 of the present embodiment protrudes laterally from the side surface of the front half of the column main body portion 11 and overlaps the front side of the PCa beam 2.

  A through hole 12 a that penetrates in the front-rear direction is formed at the center of the overhanging portion 12. The tendon 3 is inserted through the through hole 12a.

  The support portion 13 shown in FIG. 1 is a portion that supports the end portion of the PCa beam 2 in the longitudinal direction from below (see FIG. 3), and from the side of the column main body portion 11 to the side on the rear side of the overhang portion 12. It overhangs (see FIG. 4). In this embodiment, a total of four support portions 13, 13,... Are provided corresponding to the four PCa beams 2, 2,. The support portion 13 of this embodiment is made of reinforced concrete and is integrally formed with the column main body portion 11 and the overhang portion 12. As shown in FIG. 3, the rear end portion of the support portion 13 protrudes toward the existing beam B from the rear surface 11 r of the column main body portion 11, and is in contact with the front surface Bf of the existing beam B. Although not shown, a filler (such as non-shrink mortar or epoxy resin) may be interposed between the support portion 13 and the existing beam B.

  The PCa beam 2 shown in FIG. 1 is made of a precast member (PCa member) made of reinforced concrete. The PCa beam 2 of this embodiment is a precast prestressed concrete member (PCaPC member) in which prestress (compression force) is introduced in the axial direction thereof.

  The PCa beam 2 includes a beam main body portion 21 arranged along the front surface of the existing beam B, and joint end portions 22 and 22 that are superimposed on the rear side of the overhanging portion 12 of the PCa column 1.

  The beam main body 21 is positioned on the front side of the existing beam B and is crimped to the front surface Bf of the existing beam B as shown in FIG. In this embodiment, the rear surface 21r of the beam main body 21 is brought into contact with the front surface Bf of the existing beam B. However, a filler (such as non-shrink mortar or epoxy resin) is provided between the beam main body 21 and the existing beam B. Can be interposed.

  The joint end portion 22 is a portion that is superimposed on the overhanging portion 12 of the PCa column 1 and is a portion that is placed on the support portion 13 of the PCa column 1 (see FIG. 3), and the longitudinal direction of the PCa beam 2 It is formed in the edge part. As shown in FIG. 4, the joining end portion 22 of the present embodiment is obtained by extending the upper half portion of the beam main body portion 21 toward the PCa column 1 and is formed integrally with the beam main body portion 21. Yes. The beam length (height dimension) at the joint end portion 22 is smaller than the beam width at the beam body portion 21, and the beam width at the joint end portion 22 is the same as the beam width at the beam body portion 21. Further, the upper surface of the joining end portion 22 is flush with the upper surface of the overhang portion 12.

  As shown in FIG. 3, the joining end 22 is sandwiched between the overhanging portion 12 of the PCa column 1 and the existing beam B, and the front surface 22 f of the joining end 22 is the rear surface of the overhanging portion 12 of the PCa column 1. 12r, the rear surface 22r of the joining end 22 is in contact with the front surface Bf of the existing beam B. Although illustration is omitted, a filler (such as non-shrinking mortar or epoxy resin) may be interposed between the overhang portion 12 and the joining end portion 22 and between the joining end portion 22 and the existing beam B. There is no problem.

  As shown in FIG. 2, the end surface 22 t of the joining end portion 22 is abutted against the side surface of the column main body 11 of the PCa column 1 and the side surface of the existing column P. In the present embodiment, the end surface 22t of the joining end surface 22 is directly butted against the side surface of the column main body 11 and the side surface of the existing column P. However, the end surface 22t may be butted via a filler (such as non-shrink mortar or epoxy resin). Absent.

  A through hole 22 a penetrating in the front-rear direction is formed in the joint end portion 22 at a position corresponding to the through hole 12 a of the overhanging portion 12. The tendon 3 is inserted through the through hole 22a.

  The tendon material 3 penetrates the overhanging portion 12, the joint end portion 22 and the existing beam B, and is fixed to the overhanging portion 12 and the existing beam B in a state where a tensile force is introduced. Although there is no restriction | limiting in the material etc. of the tension material 3, The thing of this embodiment consists of PC steel materials (for example, PC steel rod). Male threads are formed at both ends of the tendon 3.

Next, the construction method of the seismic reinforcement structure according to this embodiment will be described.
As shown in FIG. 4, first, a through hole Ba is formed at a predetermined position of the existing beam B. Subsequently, the PCa column 1 and the PCa beam 2 are placed on the existing frame (the existing column P and the existing column) while the overhanging portion 12 of the PCa column 1 and the joint end portion 22 of the PCa beam 2 are overlapped in the beam width direction of the existing beam B. Temporarily assembled on the front side of beam B). When another PCa column 1 is already installed below the PCa column 1 to be temporarily assembled, the PCa column 1 to be temporarily assembled is placed on the upper surface of the lower PCa column 1 and both Join.

  There are no particular restrictions on the installation order of the PCa column 1 and the PCa beam 2, and after the PCa beam 2 is temporarily placed on the front side of the existing beam B, the left and right PCa columns 1 and 1 may be temporarily placed. After temporarily placing the columns 1 and 1, the PCa beam 2 may be installed between the support portions 13 and 13 of the PCa columns 1 and 1. If the PCa beam 2 is installed after the PCa columns 1 and 1 are temporarily placed, the PCa beam 2 can be temporarily supported on the PCa column 1, so that the support work for supporting the PCa beam 2 is omitted or reduced. It becomes possible to do.

  Subsequently, as shown in FIGS. 2 and 3, the tension member 3 is inserted through the through hole 12 a of the overhanging portion 12, the through hole 22 a of the joint end portion 22, and the through hole Ba of the existing beam B, A female screw member 3a such as a fixing plate 3b or a nut is attached to each of both ends.

  There are gaps between the PCa column 1 and the existing column P, between the PCa beam 2 and the existing beam B, between the overhanging portion 12 of the PCa column 1 and the joint end portion 22 of the PCa beam 2. If so, the gap is filled with a filler.

  Thereafter, a tensile force is applied to each of the plurality of tension members 3, 3,..., And both ends of each tension member 3 are fixed to the overhanging portion 12 of the PCa column 1 and the existing beam B in this state. Although there is no restriction | limiting in the introduction method of tension | tensile_strength, For example, one end of the tension | tensile_strength material 3 may be pulled with a center hole jack etc., and the internal thread member 3a should just be tightened in this state.

  When the tension members 3, 3,... Imparted with a tensile force are fixed to the overhanging portions 12, 12,... And the existing beam B, the column main body portion 11 is pressure-bonded to the front surface Pf of the existing column P. As a result, the beam end portion 22 is clamped to the front surface Bf of the existing beam B.

  According to the seismic strengthening structure of the present embodiment configured as described above, the shear force acting on the existing frame (the existing column P and the existing beam B) is the same as that of the additional frame (PCa column 1 and PCa beam 2). Since it is transmitted to the additional frame via a frictional force (crimping force) acting between the existing frame and the post-construction anchor as a shear transmission member can be omitted or reduced.

  In addition, according to the seismic reinforcement structure of the present embodiment, the tension members 3, 3,... Are penetrated at positions avoiding the panel zones (column beam joints) of the existing frame. It is possible to avoid drilling holes in the joint.

  In the present embodiment, the end face in the longitudinal direction of the PCa beam 2 (the end face 22t of the joint end 22) is abutted against the side face of the PCa pillar 1 and the side face of the existing pillar P. A part of the shearing force is directly transmitted to the PCa beam 2. That is, according to the seismic reinforcement structure of the present embodiment, the shear transmission mechanism is formed by the physical meshing action between the extension frame (PCa column 1 and PCa beam 2) and the existing column P, and a part of the shear force during the earthquake Can be directly transmitted to the additional frame, so that the load applied to the tendon 3 can be reduced.

  Moreover, according to the seismic reinforcement structure of this embodiment, since the upper and lower surfaces of the overhanging portion 12 of the PCa pillar 1 and the upper and lower surfaces of the PCa beam 2 are flush with each other, the shape viewed from the front is clean. Become a thing. In addition, since the PCa pillar 1 and the PCa beam 2 are arranged along the front side of the existing pillar P and the existing beam B, respectively, there is no possibility of reducing the opening area such as the window opening.

  In this embodiment, the case where the joining end portion 22 of the PCa beam 2 is overlapped with the rear side of the overhanging portion 12 of the PCa column 1 is illustrated. However, as illustrated in FIG. You may superimpose on the front side of the part 12. In this case, what is necessary is just to fix the both ends of the tension | tensile_strength material 3 which provided the tensile force to the joining end part 22 and the existing beam B. FIG. In this way, the beam main body 21 is pressure-bonded to the front surface of the existing beam B, and the protruding portion 12 is sandwiched between the joining end portion 22 and the existing beam B. As a result, the column main body portion 11 and the protruding portion 12. Is pressure-bonded to the front surfaces of the existing pillar P and the existing beam B.

  In this embodiment, the case where the beam main body portion 21 of the PCa beam 2 is pressure-bonded to the front surface of the existing beam B is illustrated, but the beam main body portion 21 may be arranged in a state of being separated from the front surface of the existing beam B.

  Moreover, although the case where the overhang | projection part 12 of the PCa pillar 1 was made into the front view rectangle was illustrated in this embodiment, of course, even if it shape | molds in another shape, it does not interfere. Moreover, although the case where the support part 13 was provided in the PCa pillar 1 was illustrated in the present embodiment, the support part 13 may be omitted.

  In the present embodiment, the case where the beam cause of the joint end portion 22 of the PCa beam 2 is made smaller than the beam cause of the beam main body portion 21 is exemplified, but the form of the PCa beam 2 is not limited. As shown in FIG. 6, the beam of the joint end 22 of the PCa beam 2 may be equal to the beam of the beam main body 21. In this case, for example, the beam width of the lower half portion of the joint end portion 22 is made smaller than the beam width of the upper half portion, and the joint end portion 22 is formed in an inverted L-shaped cross section, The half part may be placed on the support part 13 of the PCa pillar 1. Although not shown, the cross-sectional shape of the joining end portion 22 of the PCa beam 2 may be the same as the cross-sectional shape of the beam main body portion 21.

  In this embodiment, although the case where the one tension member 3 was penetrated per one overhang | projection part 12 was illustrated, you may penetrate a plurality of the tension members 3 per one overhang | projection part 12. FIG. Although not shown, a tension material to which a tensile force is applied may be provided through the column main body 11 and the existing column P so that the column main unit 11 is more firmly bonded to the existing column P. Similarly, a tension member to which a tensile force is applied may be provided through the beam main body 21 and the existing beam B so that the beam main body 21 is more firmly bonded to the existing beam B. In addition, when penetrating a tension material through the existing pillar P, it is desirable to avoid a joint (panel zone) with the existing beam B.

  In this embodiment, the case where the tension material 3 is inserted through the through holes 12 a and 22 a formed in the overhang portion 12 and the joint end portion 22 is illustrated, but the tension material 3 is embedded in the overhang portion 12 and the joint end portion 22. You may keep it.

DESCRIPTION OF SYMBOLS 1 PCa pillar 11 Column main-body part 12 Overhang | projection part 13 Support part 2 PCa beam 21 Beam main-body part 22 Joining end part 3 Tension material P Existing pillar B Existing beam

Claims (3)

A seismic reinforcement structure comprising a PCa column and a PCa beam,
The PCa column has a column main body portion arranged along the front surface of the existing column, and an overhang portion projecting sideways from the column main body portion,
The PCa beam has a beam main body portion arranged along the front surface of the existing beam, and a joining end portion superimposed on the front side or the rear side of the overhanging portion,
A seismic reinforcement structure characterized in that the column main body portion is pressure-bonded to the front surface of the existing column by applying a tensile force to a tension member that penetrates the overhanging portion, the joining end portion, and the existing beam. The PCa pillar has a support part that protrudes laterally from the pillar body part,
The seismic reinforcement structure according to claim 1, wherein the joint end portion of the PCa beam is placed on an upper surface of the support portion.   The joint end portion of the PCa beam is overlapped on the rear side of the overhang portion, and the end surface of the joint end portion is abutted against the side surface of the PCa column and the side surface of the existing column. The earthquake-proof reinforcement structure of Claim 1 or Claim 2.

Images