JP2015086557A - Earthquake-proof repair method for existing building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earthquake-proof repair method for an existing building, which can enhance a vibration control effect while still staying in the existing building.SOLUTION: An earthquake-proof repair method for an existing building includes: a frame forming step of forming a lattice-shaped frame 24 by laying steel beams 26, 28, 30 and 32 among columns 16 configuring an upper structure 14 of the existing building; and a mass body installation step of installing a mass body 38 on the frame 24 in such a manner that it can move relative to the frame or installing the mass body 38 on the frame 24 and supporting the upper structure via a base-isolating device by a lower structure.

Description

  The present invention relates to a seismic retrofit method for an existing building.

  In the renovation work that improves the seismic performance of existing buildings, there is a demand for a method of renovation without leaving the house. As an example of such a method, the top floor part (upper structure) and the lower floor part (lower structural zone) of an existing building are separated, and a seismic isolation device is installed between the top floor part and the lower floor part. A method for damping the lower floor portion is disclosed (for example, Patent Document 1).

JP-A-62-273374

  However, in the above-mentioned Patent Document 1, since the vibration is suppressed only by the mass of the upper structure, the vibration suppression effect cannot be sufficiently obtained. On the other hand, if a mass body is installed in the upper structure, a load acting on a specific column is increased, and a reinforcement work on the lower structure is required. For this reason, seismic retrofitting becomes difficult.

  The present invention has been made in view of the above facts, and an object thereof is to provide an earthquake-proof repair method for an existing building that can enhance the vibration control effect while staying.

  A method for seismic retrofitting of an existing building according to the present invention as defined in claim 1 includes a pedestal forming step of laying a steel beam on a pillar constituting an upper structure of an existing building to form a grid-like pedestal, A mass body installation step, wherein the mass body is installed so as to be movable relative to the gantry, or the mass body is installed on the gantry and the upper structure is supported by the lower structure via a seismic isolation device; Have.

  According to the seismic retrofit method for an existing building according to the first aspect of the present invention, the gantry is formed by laying steel beams in a lattice form on the columns constituting the upper structure of the existing building in the gantry forming step. And in a mass body installation process, a mass body is installed on this mount so that relative movement is possible, and a building is damped. Alternatively, the mass body is placed on the gantry so as not to be relatively movable, and the upper structure is supported by the lower structure via the seismic isolation device, so that the upper structure functions as a vibration damping device. In this way, by installing the mass body on the gantry in the mass body installation step, it is possible to distribute the mass body load to the plurality of columns along the steel beam without performing the reinforcement work of the lower structure The vibration control effect can be enhanced. Alternatively, it is possible to minimize the reinforcement work of the substructure.

  The seismic retrofit method for an existing building according to the present invention described in claim 2 is the seismic retrofit method for an existing building according to claim 1, wherein the steel beam includes a steel beam installed between the columns, A steel small beam erected between the steel large beams, a part of the steel large beams and the columns are joined by pin joining, the remaining steel large beams and the columns are joined, and the steel large beams and the steel frames It is characterized in that the joint with the beam is a rigid joint.

  According to the seismic retrofitting method for an existing building according to claim 2 of the present invention, it is possible to suppress the load from being transmitted only to a specific column and to distribute the load efficiently to other columns through the steel beam. be able to. For example, a steel large beam and a column supporting the mass body below the mass body are pin-joined, and the joint between the steel large beam and the steel small beam is rigidly joined, so that the load of the mass body is further applied to the steel beam. Can communicate a lot.

  The earthquake-proof repair method for an existing building according to the present invention described in claim 3 is the earthquake-proof repair method for an existing building according to claim 1 or 2, wherein the mass body installation step cuts the pillar. A column cutting step that divides the upper structure and the lower structure, and a seismic isolation device installation step that installs a seismic isolation device at the cut portion of the column, and the gantry on the seismic isolation device And the mass body is installed.

  According to the seismic retrofit method for an existing building according to the third aspect of the present invention, the upper structure can be caused to function as a vibration damping device. Thereby, compared with the case where a damping device is installed in an upper structure, the mass of a mass body can be made small.

  As explained above, according to the seismic retrofitting method for an existing building according to the present invention, the vibration damping effect can be enhanced while staying.

It is sectional drawing which shows the building after earthquake-proof repair which concerns on 1st embodiment of this invention. It is the plane sectional view cut | disconnected by 2-2 line | wire of FIG. FIG. 3 is a cross-sectional plan view showing the gantry with the vibration damping device removed from the state of FIG. 2. It is the schematic diagram which showed an example of pin joining. It is the schematic diagram which showed an example of rigid joining. It is a plane sectional view showing the state where the load of the mass body is dispersed. It is sectional drawing which shows the building after earthquake-proof repair which concerns on 2nd embodiment of this invention. It is sectional drawing which shows the state before the earthquake-proof repair of a building.

<First embodiment>
Hereinafter, the building 10 after earthquake-proof repair which concerns on 1st embodiment of this invention is demonstrated, referring drawings. The term “seismic retrofit” refers to a retrofit that prevents building structures and civil engineering structures from being destroyed or damaged by an earthquake. Including the concept of In addition, in this embodiment, an embodiment in which a high-rise tenant building of 50 floors or more is earthquake-proofed will be described. However, the present invention is not limited to this. May be. The same applies to the second embodiment. Furthermore, an arrow Z appropriately shown in each figure indicates the height direction (vertical direction) of the building 10, and arrows X and Y appropriately indicated in each figure indicate two horizontal directions orthogonal to each other.

(Configuration of building 10 after earthquake-proof repair)
As shown in FIG. 1, the building 10 of this embodiment includes a building body 12 as a lower structure and a tower 14 as an upper structure. The building body 12 is composed of a ramen structure including an existing column 16 and an existing beam 18. In the present embodiment, as an example, a reinforced concrete structure (RC structure) is used. However, the present invention is not limited to this. For example, a steel structure (S structure), a steel reinforced concrete structure (SRC structure), or a concrete-filled steel pipe structure (CFT structure) may be used.

  A tower 14 as an upper structure is provided at the uppermost part (the roof) of the building body 12. The tower 14 includes a pillar 16 constituting the building body 12 and an existing beam 20 installed between the pillars 16. In this embodiment, the tower 14 is a two-story tower 14 as an example. . However, the present invention is not limited to this, and a single-storey tower may be used, or three or more floors may be used. Further, a structure other than the tower 14 may be used as the upper structure. Further, in the case of a building where the tower 14 is not provided, the top floor portion of the building may be an upper structure.

  A machine room 22 similar to a general building is provided in the central portion of the tower 14. The machine room 22 is provided from the first floor to the second floor of the tower 14, and the machine room 22 accommodates electrical equipment and air conditioning equipment (not shown).

  Here, a gantry 24 is formed on the second floor of the tower 14. The gantry 24 is formed above the beam 20 that separates the first floor portion and the second floor portion of the tower 14, and as shown in FIG. 2, a grid is formed by the steel large beams 26, 28, 30 and the steel small beams 32. Is formed. The steel large beam 26 is a beam member erected between the columns 16. In this embodiment, an H-shaped steel is used as an example, but the present invention is not limited to this, and other steel shapes such as a T-shaped steel and an I-shaped steel are used. Shape steel may be used. The same applies to the large steel beams 28 and 30 and the small steel beam 32 described below.

  Two steel beams 26 are provided on each side of the machine room 22, and are installed between the columns 16 in the Y direction. In addition, a steel beam 28 is installed between the steel beam 26 in parallel with the steel beam 26. The steel large beam 28 is installed between the columns 16 in the Y direction, and supports the mass body 38 below the mass body 38. Here, the steel beam 28 is a steel beam having lower rigidity than the steel beam 26.

  A steel beam 30 is provided between the column 16 on which the steel beam 26 is installed and the column 16 on which the steel beam 28 is installed. The steel beams 30 are installed between the columns 16 in the X direction. In the present embodiment, as an example, eight steel beams 30 are provided along one side and the opposite side of the tower 14.

  On the other hand, a steel beam 32 is installed between the steel beam 26 and the steel beam 28. As shown in FIG. 3, the steel beam 32 is installed in the X direction at a position where the steel beam 26 is equally divided, and is joined to the steel beam 26 and the steel beam 28. Thus, the lattice-like mount 24 formed by the steel large beams 26, 28, 30 and the steel beam 32 is provided at two locations on both sides of the machine room 22. In the present embodiment, the steel beam 30 is also installed on the column between the two gantry 24, and the load acting on each gantry 24 can be transmitted. The steel beams 30 need not be installed on the columns 16 between the mounts 24.

  A horizontal brace 34 is installed in an oblique direction between the steel large beams 26, 28, 30, the steel beam 32, and the column 16 to reinforce the tower 14 with earthquake resistance. As shown in FIG. 1, cross-shaped vertical braces 35 are respectively constructed on the first floor portion and the second floor portion of the tower 14. The shape of the horizontal brace 34 and the vertical brace 35 is not particularly limited. For example, the horizontal brace 34 may have a cross shape like the vertical brace 35. Moreover, when the intensity | strength with respect to the horizontal force and vertical force of the tower 14 is fully ensured, the horizontal brace 34 and the vertical brace 35 do not need to be constructed.

  Here, the steel beam 28 and the column 16 are joined by pin joining. Specifically, as shown in FIG. 4, the steel beam 28 and the column 16 are pin-joined via a gusset plate 42. The gusset plate 42 is a rigid plate welded to the surface of the column, and a plurality of bolt holes are formed in the gusset plate 42, and the web portion 28B of the steel beam 26 is overlaid on the gusset plate 42. They are joined by a plurality of bolts 44 and nuts (not shown). Since the pins are joined in this way, the flange portion 28A of the steel beam 26 and the column 16 are not joined.

  On the other hand, the steel large beam 28 and the steel small beam 32 are joined rigidly. Specifically, as shown in FIG. 5, the steel beam 32 is arranged such that a pair of upper and lower flange portions 32 </ b> A thereof are continuous with a pair of upper and lower flange portions 28 </ b> A of the steel beam 28. The end of the flange portion 32A of the steel beam 32 and the end of the flange portion 28A of the steel beam 28 are joined by welding. Thereby, the steel large beam 28 and the steel small beam 32 are rigidly joined so that a bending moment can be transmitted.

  Further, the large steel beam 28 is provided with gusset plates 46 on both sides of the web portion 28B, and a plurality of bolts 48 and nuts (not shown) in a state where the web portion 32B of the steel small beam 32 is overlapped on the gusset plate 46. Are joined by. However, the present invention is not limited thereto, and the steel large beam 28 and the steel small beam 32 may be rigidly joined by other methods. For example, the web portion 32B of the steel small beam 32 is protruded from the flange portion 32A, and the steel large beam 28 is projected. The flange portion 28A and the web portion 28B may be welded.

  As shown in FIG. 2, the remaining steel beams 26 and 30 excluding the steel beam 28 and the column 16 are rigidly bonded. A vibration damping device 36 is installed on the gantry 24. The vibration damping device 36 mainly includes a mass body 38 and a support base 40 that supports the mass body 38 so as to be relatively movable with respect to the base 24. In the present embodiment, as an example, two bases 24 are provided. The same vibration damping device 36 is installed in each.

  The mass body 38 is formed in a substantially rectangular parallelepiped shape, and the mass of the mass body 38 is appropriately set according to the weight of the building 10 and the required damping performance. In the present embodiment, a 700 t mass body 38 is used as an example.

  The support base 40 includes a linear slider (not shown), and supports the mass body 38 so as to be movable relative to the gantry 24 in the X direction and the Y direction. However, the present invention is not limited to this, and the mass body 38 may be supported so as to be relatively movable using an elastic body such as laminated rubber, or a sliding bearing may be used. Further, the mass body 38 may be suspended and formed into a pendulum type. Here, the building 10 is provided with damping means (not shown) such as an oil damper, and constitutes a TMD (Tuned Mass Damper).

  For this reason, when vibration energy is input to the building 10 due to wind vibration or earthquake, the mass body 38 moves relative to the gantry 24, and the vibration energy of the building 10 is converted into kinetic energy of the mass body 38 and absorbed. . Thereby, the vibration of the building 10 can be reduced.

  In addition, in this embodiment, although it is the structure which is damped by TMD, it is not restricted to this, It is good also as AMD (Active Mass Damper) which moves a mass body actively and dampens. As an example of this AMD, an actuator and a sensor are attached to the mass body 38, and the mass body 38 is moved relative to the gantry 24 by operating the actuator according to the magnitude of vibration energy input to the building 10. There is a way to control vibration.

(Building 10 earthquake-proof repair method)
Next, the earthquake-proof repair method of the building 10 of this embodiment is demonstrated. As shown in FIG. 8, the building 10 before the earthquake-resistant repair includes a building main body 12 composed of columns 16 and beams 18, and a tower 14 provided on the roof of the building main body 12. Further, the tower 14 uses a column 16 similar to that of the building body 12, and a beam 18 is installed on the column 16. Furthermore, a machine room 22 is provided in the central portion of the tower 14.

  In the state of FIG. 8, as shown in FIG. 3, the steel frame large beams 26, 28, 30 and the steel beam 32 are installed on the column 16 of the tower 14 to form the lattice-shaped frame 24 (the frame forming step). ). At this time, as described above, the joint between the steel beam 28 and the column 16 is a pin joint (see FIG. 4). Further, the steel large beam 28 and the steel small beam 32 are joined rigidly (see FIG. 5). Furthermore, the steel large beam 26 and the column 16 are joined by rigid joining, and the steel large beam 30 and the column 16 are joined by rigid joining.

  Next, a horizontal brace 34 and a vertical brace 35 are installed on the tower 14 as necessary. Then, as shown in FIG. 2, a support base 40 is installed at the central part of the gantry 24 formed at two places, and a mass body 38 is installed on the support base 40. That is, the mass body 38 is installed on the gantry 24 so as to be movable relative to the gantry 24 (mass body installation step).

  As described above, the earthquake-proof repair of the building 10 can be performed. Here, reinforcement work of the pillar 16 may be performed as necessary. In the present embodiment, the gantry 24 is formed inside the tower 14, but the gantry 24 is not limited to this, and the gantry 24 may be formed in another location. For example, a frame may be formed on the roof, and the mass body 38 may be installed on the frame so as to be relatively movable. Further, in the case of a building in which the tower 14 is not provided, the pedestal 24 may be formed on the uppermost floor portion with the upper structure above the uppermost floor portion of the building.

(Function and effect)
Next, the effect | action and effect of the earthquake-proof repair method of the building 10 of this embodiment are demonstrated. In the seismic retrofit method of this embodiment, the grid-like gantry 24 is formed in the gantry forming step, and the mass body 38 is installed on the gantry 24. For this reason, as shown in FIG. 6, the load of the mass body 38 is distributed to the plurality of columns 16 through the steel beam 32 and the steel beam 26. Thereby, it can suppress that the load of the mass body 38 acts on the specific pillar 16 compared with the case where the mass body 38 is installed, without forming the grid | lattice-like mount frame 24. FIG.

  In particular, as in the present embodiment, when renovation is performed so that the appearance of the building 10 does not change before and after the earthquake-proof renovation, it is necessary to install the vibration damping device 36 including the mass body 38 inside the existing structure. . That is, the vibration damping device 36 must be installed in a limited space, but a relatively large mass body 38 is formed by forming the grid-like frame 24 and installing the vibration damping device 36 on the frame 24. Even if it installs, it can suppress that an excessive load acts on the existing pillar 16. FIG. Thereby, earthquake-proof repair can be performed without harming the design of the building 10.

  Further, in the present embodiment, the connection between the steel beam 28 and the column 16 installed below the mass body 38 is a pin connection, and the connection between the steel beam 26 and the column 16 located away from the mass body 38 is performed. The joint between the steel beam 30 and the column 16 is a rigid joint. Furthermore, the steel large beam 28 and the steel small beam 32 are joined by rigid joining. In this way, the connection of a part of the steel beam 28 and the column 16 is a pin connection and the rest is a rigid connection, so that the load of the mass body 38 is easily transmitted from the steel beam 28 to the steel beam 32. The load of the mass body 38 can be dispersed efficiently.

  Further, by making the beam width of the steel large beam 28 smaller than the beam width of the steel large beam 26, the load of the mass body 38 is easily transmitted to the steel large beam 26 having high rigidity. In addition, when the load of the mass body 38 can be distributed without reducing the rigidity of the steel beam 28, the steel beam 28 may have the same shape as the steel beam 26.

  By performing the earthquake-resistant repair as described above, the reinforcement work on the building main body 12 is not required, and normal operations can be performed by each tenant of the building main body 12 even during the earthquake-proof repair. In addition, even if reinforcement work is necessary, it can be limited to the minimum reinforcement, and the time required for the reinforcement work in the building body 12 can be shortened. Furthermore, when the building 10 is a high-rise apartment or the like and includes a residential space, the earthquake-proof repair can be performed without imposing a burden on the inhabitants of each residence of the building body 12.

<Second embodiment>
Next, the earthquake-proof repair method of the existing building which concerns on 2nd embodiment of this invention is demonstrated. Similar to the first embodiment, the building 50 after the earthquake-resistant repair according to the present embodiment includes a building body 12 and a tower 14, and the building body 12 includes an existing column 16 and an existing beam 18. It is composed of a ramen structure that contains it.

  The tower 14 includes a pillar 16 constituting the building body 12 and an existing beam 20 installed between the pillars 16. A machine room 22 is provided in the central portion of the tower 14. Yes. Here, in the present embodiment, the first floor portion 14A and the second floor portion 14B of the tower 14 are divided, and the first floor portion 14A and the second floor portion 14B are provided as seismic isolation devices at the positions of the columns 16. A laminated rubber 52 is installed. The laminated rubber 52 is formed by laminating a rubber plate and a steel plate in the vertical direction. In addition, not only this but another seismic isolation apparatus may be installed, for example, a sliding bearing may be used.

  On the laminated rubber 52, the gantry 24 is formed. Since the gantry 24 has the same configuration as that of the first embodiment, the description thereof is omitted. A mass body 54 is installed on the gantry 24. Here, the mass of the mass body 54 is smaller than that of the mass body 38 of the first embodiment. Further, the tower 14 is seismically reinforced by horizontal braces and vertical braces 35 (not shown).

  Next, the earthquake-proof repair method of the building 50 of this embodiment is demonstrated. The building 50 before the seismic retrofit is in the state shown in FIG. 8 as in the first embodiment. From this state, the column 16 of the tower 14 is cut and divided into a first-floor portion 14A serving as a lower structure and a second-floor portion 14B serving as an upper structure (column cutting step).

  Next, the laminated rubber 52 is installed at the cut portion where the pillar 16 is cut, and the second floor portion 14B is supported by the first floor portion 14A via the laminated rubber 52 (seismic isolation device installing step). Here, in this embodiment, the laminated rubber 52 is installed at all the positions of the pillars 16 that have been cut. However, the present invention is not limited to this, and the laminated rubber 52 may be thinned and installed. Further, the laminated rubber 52 may be separately installed at a position other than the position of the pillar 16. Further, a sliding bearing such as a linear slider having a lower horizontal rigidity than the laminated rubber 52 may be used. In this case, it is set as the structure provided with the restoring force using laminated rubber, a spring, etc.

  Next, the gantry 24 is formed on the laminated rubber 52. The method of forming the gantry 24 is the same as that of the first embodiment. As shown in FIG. 3, the gantry 24 is formed by laying the steel large beams 26, 28, 30 and the steel small beam 32 between the columns 16. To do.

  After forming the gantry 24, the mass body 54 is installed on the gantry 24. In this embodiment, the steel plate 56 is provided on the gantry 24 and the mass body 54 is installed on the steel plate 56. However, the present invention is not limited to this, and the mass body 54 is installed directly on the gantry 24. May be. Alternatively, the existing beam 20 may be reinforced and the mass pair 54 may be suspended from the beam 20.

  After the mass body 54 is installed, a horizontal brace and a vertical brace 35 are installed as necessary. The horizontal brace and the vertical brace 35 may be installed immediately after the gantry 24 is formed.

  By isolating the second floor portion 14B of the tower 14 as described above, when vibration energy is input to the building 50 due to wind vibration or earthquake, the second floor portion 14B moves relative to the first floor portion 14A, and the building 50 vibration energy is converted into kinetic energy of the second floor portion 14B and absorbed. Thereby, since the 2nd floor part 14B of the tower 14 can be functioned as TMD, the mass of the 2nd floor part 14B can also be considered and the mass of the mass body 54 can be made smaller than 1st embodiment. Other operations are the same as in the first embodiment.

  In the present embodiment, the first floor portion 14A and the second floor portion 14B of the tower 14 are divided. However, the present invention is not limited to this, and the column 16 may be cut between the building body 12 and the tower 14. In this case, the laminated rubber 52 can be installed between the building body 12 and the tower 14 so that the entire tower 14 can function as TMD.

  As mentioned above, although 1st embodiment of this invention and 2nd embodiment were described, this invention is not limited to such embodiment, You may use combining embodiment and various modifications suitably, Needless to say, the present invention can be implemented in various modes without departing from the gist of the present invention. For example, the gantry 24 may be formed in a plurality of layers.

10 Building 12 Building body (substructure)
14 Tower (superstructure)
14A 1st floor part (lower structure)
14B Second floor part (superstructure)
16 Pillar 24 Base 26 Steel beam (steel beam)
28 Steel beam (steel beam)
30 Steel beam (steel beam)
32 Steel beam (steel beam)
38 Mass body 50 Building 52 Laminated rubber (Seismic isolation device)
54 Mass

Claims (3)

A pedestal formation process in which a steel beam is installed on a pillar constituting the upper structure of an existing building to form a grid-like pedestal;
A mass body that is installed on the gantry so as to be movable relative to the gantry, or that the mass body is installed on the gantry and the upper structure is supported by the lower structure via a seismic isolation device. Installation process;
Seismic retrofitting method for existing buildings. The steel beam comprises a steel large beam constructed between the columns, and a steel small beam constructed between the steel large beams.
2. A part of the steel beam and the column are joined by pin joining, and the remaining steel beam and the column and the steel beam and the steel beam are joined rigidly. Seismic retrofit method for existing buildings. The mass body installation step includes a column cutting step of cutting the column and dividing the column into the upper structure and the lower structure;
A seismic isolation device installation step of installing a seismic isolation device at the cut portion of the pillar;
Have
The earthquake-proof repair method of the existing building of Claim 1 or 2 which forms the said mount on the said seismic isolation apparatus, and installs the said mass body.

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