JP7581985B2 - Seismic isolation methods and structures - Google Patents

Description

The present invention relates to a seismic isolation method and a seismic isolation structure.

A seismic isolation method is being implemented in which columns of an existing building are cut and then seismic isolation devices are installed at the cut points to achieve seismic isolation. The existing building is separated into an upper structure and a lower structure with the seismic isolation device in between, and the wall is also separated into a side connected to the upper structure and a side connected to the lower structure. In Patent Document 1, the separated upper wall and lower wall are connected with a seismic plate to ensure resistance to horizontal external forces (earthquakes, etc.) acting on the building until the installation of the seismic isolation device is completed.
As disclosed in Patent Document 1, an earthquake-resistant plate 91 (see Figs. 14A and 14B) is generally attached to the walls 51, 52 by fastening members 92 (e.g., anchor bolts, nuts, etc.) inserted into through holes 93 provided in the upper and lower separated walls 51, 52. In this case, resistance to horizontal external forces in a direction along the wall surface can be ensured by the shear strength of the fastening members 92 and the frictional force between the wall surface and the earthquake-resistant plate 91 generated by the fastening members 92.

JP 2001-311314 A

However, when installing the earthquake-resistant plate 91 using the above method, through-holes 93 must be formed in both the upper wall 51 and the lower wall 52, and the through-holes 93 must be backfilled after the earthquake-resistant plate 91 is removed. Also, in order to avoid damaging the reinforcing bars embedded in the walls 51 and 52 when forming the through-holes 93, it is desirable to inspect the walls 51 and 52 for reinforcing bars before forming the through-holes 93. As such, the above-mentioned method of installing the earthquake-resistant plate 91 is time-consuming.

The present invention was made in consideration of these problems, and its purpose is to facilitate the construction of seismic isolation works while maintaining the resistance to horizontal external forces acting on the building during construction, allowing the work to be carried out safely.

In order to achieve this objective, the seismic isolation method of the present invention is a seismic isolation method in which a seismic isolation device is provided between an upper structure and a lower structure, the upper structure having an upper horizontal portion and an upper protruding portion protruding downward from the upper horizontal portion, the lower structure having a lower horizontal portion and a lower protruding portion protruding upward from the lower horizontal portion, a first surface material is installed vertically across the gap between the upper protruding portion and the lower protruding portion and along one side surface of the upper protruding portion in the horizontal direction and the one side surface of the lower protruding portion, and a first surface material is installed vertically across the gap and along the front side of the lower protruding portion in the horizontal direction. The method includes a surface material installation process for installing a second surface material along the other side surface of the upper protrusion and the other side surface of the lower protrusion; a pressure bonding process for pressure bonding the first surface material and the second surface material to the upper protrusion and the lower protrusion using a first fastening member inserted in the horizontal direction through the through hole, the gap, and the through hole of the first surface material, and a second fastening member screwed into the first fastening member; and a seismic isolation device installation process for installing the seismic isolation device between the upper structure and the lower structure after the pressure bonding process.

According to this type of seismic isolation method, the frictional force generated between the surface material and the upper and lower protrusions can counter horizontal external forces acting on the building. Therefore, even if columns or the like are cut during construction, the positional displacement of the upper structure relative to the lower structure can be suppressed, allowing for safe construction. Furthermore, in order to enable the seismic isolation device to function, the first fastening member is inserted into the gap formed by separating the upper and lower protrusions, so there is no need to form holes in the upper and lower protrusions just for the purpose of inserting the first fastening member, or to backfill the holes after removing the surface material, making construction easier.

In the seismic isolation method, in the pressure bonding step, a first bonding plate is bonded to the one surface of the first face material in the horizontal direction, and
The present invention is characterized in that, with a second adhesive plate attached to the other side surface of the face material, the first face material and the second face material are pressure-bonded to the upper protrusion and the lower protrusion.

With this type of seismic isolation method, the tension of the first fastening member acts evenly over a wide area of the panel. This allows the panel to be firmly crimped and joined to the upper and lower protrusions, increasing the frictional force generated between them and increasing the building's resistance to horizontal external forces.

This seismic isolation method is characterized in that the first splice plate and the second splice plate are configured by stacking a plurality of splice plates in the horizontal direction.

This seismic isolation method allows the horizontal distance from the tightening position of the second fastening member to the panel to be increased, so the tension of the first fastening member acts evenly over a wider area of the panel. This allows the panel to be firmly crimped and joined to the upper and lower protrusions, increasing the frictional force generated between them and increasing the building's resistance to horizontal external forces.

In this seismic isolation method, the pressure bonding process is characterized by having a filling process in which a filler is filled between the first panel and the upper and lower protrusions, and between the second panel and the upper and lower protrusions.

This type of seismic isolation method allows the surface material to be tightly attached to the upper and lower protrusions via the filling material, without any gaps. This allows the surface material to be firmly pressure-bonded to the upper and lower protrusions, increasing the frictional force generated between them and increasing the building's resistance to horizontal external forces.

This seismic isolation method is characterized in that the upper protrusion and the lower protrusion are walls extending in the vertical direction between the upper horizontal section and the lower horizontal section, and includes a gap forming process in which, prior to the panel installation process, the wall is cut to separate the upper protrusion and the lower protrusion, and the gap is formed.

With this type of seismic isolation construction method, the first fastening member can be inserted into the gap formed by separating the wall into upper and lower parts to allow the seismic isolation device to function. In addition, since the wall can be cut before cutting the columns, etc. to install the seismic isolation device, seismic isolation construction can be carried out efficiently.

In this seismic isolation method, the upper structure has another upper protruding part protruding downward from the upper horizontal part, and the lower structure has another lower protruding part protruding upward from the lower horizontal part, and in the seismic isolation device installation process, the seismic isolation device is installed between the other upper protruding part and the other lower protruding part, and the length of the gap in the vertical direction is shorter than the length of the seismic isolation device in the vertical direction.

With this type of seismic isolation method, by narrowing the gap, the tension of the first fastening member can be received by the upper and lower protrusions rather than by the space in the gap. This makes it possible to efficiently generate friction between the face material and the upper and lower protrusions, and also to suppress bending of the face material.

Also, a seismic isolation structure having an upper structure having an upper horizontal portion and an upper protruding portion protruding downward from the upper horizontal portion, a lower structure having a lower horizontal portion and a lower protruding portion protruding upward from the lower horizontal portion, and a seismic isolation device installed between the upper structure and the lower structure, comprising: a first panel that vertically spans the gap between the upper protruding portion and the lower protruding portion and is installed along one side surface of the upper protruding portion and the one side surface of the lower protruding portion in the horizontal direction; a second panel that vertically spans the gap and is installed along the other side surface of the upper protruding portion and the other side surface of the lower protruding portion in the horizontal direction; a first fastening member that crimps and joins the first panel and the second panel to the upper protruding portion and the lower protruding portion; and a second fastening member that screws into the first fastening member.
The seismic isolation structure is characterized in that the first fastening member is inserted along the horizontal direction through a through hole provided in the first surface material, the gap, and a through hole provided in the second surface material.

With this type of seismic isolation structure, the frictional force generated between the surface material and the upper and lower protrusions can counter horizontal external forces acting on the building. Therefore, even if columns or the like are cut during construction, the upper structure can be prevented from shifting in position relative to the lower structure. In addition, in order to function the seismic isolation device, the first fastening member is inserted into the gap formed by separating the upper and lower protrusions, so there is no need to form holes in the upper and lower protrusions just for inserting the first fastening member, or to backfill the holes after removing the surface material, making construction easier. Note that this type of seismic isolation structure (structure that has been seismically isolated) includes a structure in the middle of the seismic isolation construction method.

The present invention makes it possible to facilitate the construction of seismic isolation structures while maintaining the building's resistance to horizontal external forces acting on it during construction, and carrying out the work safely.

FIG. 2 is a flow chart showing the procedure of the seismic isolation method of the present embodiment. FIG. 3A and 3B are explanatory views of the gap forming step. 4A and 4B are cross-sectional views illustrating the surface material installation step. 5A and 5B are diagrams showing the state in which the face materials 61 and 62 are installed. 1 is an explanatory diagram of the space S between a panel 61 and a load-bearing wall 50. FIG. 7A and 7B are explanatory diagrams of the filling step of the filler 70. FIG. A front view of the load-bearing wall 50 after the pressure bonding process has been completed. FIG. 11 is an explanatory diagram of a temporary support member installation process. An explanatory diagram of the cutting process of the pillar 2. 1 is an explanatory diagram of the installation process of the seismic isolation device 30. FIG. This is a front view of the existing building 1 after the removal process. FIG. 1 is a schematic plan view of an existing building 1. 14A and 14B are explanatory diagrams of a seismic isolation method of a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
====Embodiment====
<<S01: Reinforcement part forming process>>
Fig. 1 is a flow diagram showing the procedure of the seismic isolation method of the present embodiment. Fig. 2 is an explanatory diagram of the reinforcing portion forming process, and Fig. 2 is a front view of a reinforced existing building 1.

In the seismic isolation method of this embodiment, the existing building 1 is separated into an upper structure 10 and a lower structure 20, and a seismic isolation device 30 (e.g., laminated rubber type, rolling bearing type, sliding bearing type, etc.) is installed between them. Specifically, a part of a column 2 on an intermediate floor of the existing building 1 is cut (here, a part of the column 2 extending vertically from floor surface FL1 on the first floor above ground to floor surface FL2 on the second floor above ground is cut), and the seismic isolation device 30 is installed at the cut point.

In the following, the two columns 2A, 2B spaced apart in the X direction will be described as the target columns on which the seismic isolation device 30 is to be installed. The existing building 1 has a bearing wall 50 between the two columns 2A, 2B, with its wall surface aligned in the X direction. The part of the existing building 1 above the installation position of the seismic isolation device 30 and the cutting position of the bearing wall 50 is the upper structure 10, and the part below the installation position of the seismic isolation device 30 and the cutting position of the bearing wall 50 is the lower structure 20.

First, in order to compensate for the loss in strength and rigidity of the existing building 1 caused by separating the existing building 1 into upper and lower parts, reinforcing parts are formed to reinforce the existing building 1. For example, concrete is poured to raise the floor surface of the floor on which the seismic isolation device 30 is installed, to thicken the columns 2, and to thicken the beams 3. However, if there is no need to reinforce the existing building 1, the reinforcing part formation process is not necessary.

In this embodiment (FIG. 2), an example is shown in which an upper column reinforcement part 41 is formed by pouring concrete on the outside of the upper part of the columns 2A, 2B to be worked on, and a lower column reinforcement part 42 is formed by pouring concrete on the outside of the lower part of the columns 2A, 2B to be worked on. If the bearing wall 50 is joined integrally with the columns 2A, 2B in the existing building 1, it is advisable to cut a part of the bearing wall 50 and separate it from the columns 2A, 2B to form a space between the columns 2A, 2B and the bearing wall 50. In this way, the upper column reinforcement part 41 and the lower column reinforcement part 42 can be formed for the columns 2A, 2B.

<<S02: Gap formation process>>
3A and 3B are explanatory diagrams of the gap forming process. Fig. 3A is a front view of the existing building 1, and Fig. 3B is a cross-sectional view of a bearing wall 50 in which a gap 53 is formed.

Next, in order to allow the seismic isolation device 30 to function after installation, a gap forming process is carried out in which the bearing wall 50 is cut along the X direction to separate it into upper and lower halves, and a gap 53 is formed between them. As a result, the upper structure 10 has an upper horizontal section 11 (a section above the lower surface of the beam 3) and an upper wall 51 (upper protrusion) that is the upper part of the cut bearing wall 50 and protrudes downward from the upper horizontal section 11. The lower structure 20 has a lower horizontal section 21 (a section below the floor surface FL1 of the construction floor) and a lower wall 52 (lower protrusion) that is the lower part of the cut bearing wall 50 and protrudes upward from the lower horizontal section 21.

In addition, by cutting the bearing wall 50 along the X direction, a gap 53 (horizontal slit) that is long in the X direction is formed at the cut point, i.e., between the upper wall 51 and the lower wall 52. As shown in FIG. 3B, the gap 53 is a space that penetrates the bearing wall 50 in the Y direction perpendicular to the wall surface of the bearing wall 50.

When joining and integrating the load-bearing wall 50 (upper wall 51 and lower wall 52) to the column 2 on which the seismic isolation device 30 is installed after the seismic isolation device 30 is installed, the installation position of the seismic isolation device 30 in the vertical direction and the cutting position of the load-bearing wall 50 (the position where the gap 53 is formed) are aligned.

<<S03: Roughening process>>
Next, a roughening process is carried out on the bearing wall 50. In this embodiment, as shown in Fig. 8 described later, the surface material units 60 are installed along the wall surface of the bearing wall 50. For this reason, it is advisable to roughen the wall surface of the bearing wall 50 in the area where the surface material units 60 are to be installed. For example, unevenness is formed on the wall surface of the bearing wall 50 using a tool such as a grinder.

<<S04: Surface material installation process>>
Figures 4A and 4B are cross-sectional views explaining the surface material installation process. Figures 5A and 5B are views showing the state in which surface materials 61 and 62 are installed. Figure 5A is a cross-sectional view of the bearing wall 50 with the surface materials 61 and 62 installed, and Figure 5B is a front view of the bearing wall 50 with the surface material 61 installed. Figure 6 is an explanatory diagram of the space S between the surface material 61 and the bearing wall 50.

Next, a panel installation process is carried out to install the panel unit 60 on the load-bearing wall 50. The panel unit 60 has a first panel 61, a second panel 62, a first fastening member 63, a second fastening member 64, a first attachment plate 65, a second attachment plate 66, and a position adjustment bolt 67. In the following description, the first panel 61 and the second panel 62 are collectively referred to simply as panel 61, 62.

The first face material 61 and the second face material 62 may be, for example, a rectangular steel plate. In this embodiment, the steel plate has a thickness of 25 mm and a size of 400 mm x 470 mm (X direction x vertical direction). As shown in FIG. 5B, two first fastening members 63 are inserted into the first face material 61 and the second face material 62 at intervals in the horizontal direction (X direction). Therefore, two through holes 611, 621 (for example, holes with a diameter of 39 mm) are formed at the center of the vertical direction (vertical direction) of the first face material 61 and the second face material 62 at intervals in the horizontal direction. In addition, nuts 612, 622 are welded and integrated to the four corners of the steel plate in the first face material 61 and the second face material 62. In addition, the nuts 612, 622 are joined to the side that does not abut the wall surface in the thickness direction of the face materials 61, 62.

Examples of the first fastening member 63 include PC steel bars and bolts. In this embodiment, a PC steel bar (round steel bar) of type C No. 1 and diameter 36 mm is used. The second fastening member 64 is a member that screws into the first fastening member 63, and examples of the second fastening member 64 include nuts. In this embodiment, a hexagonal nut 641 and a round washer 642 are used. Examples of the first and second attachment plates 65 and 66 include square washers. In this embodiment, a square washer with a thickness of 38 mm and dimensions of 190 mm x 190 mm is used.

Before the facings 61 and 62 are installed on the bearing wall 50, the position adjustment bolts 67 (bolts 671) are screwed into the nuts 612 at the four corners of the first facing 61 and the nuts 622 at the four corners of the second facing 62. In the position adjustment bolts 67, the bolts 671 are screwed into anti-loosening nuts 672. As shown in FIG. 6, the ends of the bolts 671 are protruded from the faces 61b and 62a of the facings 61 and 62 on the bearing wall 50 side in the Y direction according to the desired width W (for example, 5 to 10 mm) of the space S between the facings 61 and 62 and the bearing wall 50. In addition, the anti-loosening nuts 672 are in contact with the nuts 612 and 622 of the facings 61 and 62 on the opposite side to the bearing wall 50 side in the Y direction.

In order to install the face materials 61 and 62, first, as shown in FIG. 4A, the first fastening member 63 is inserted in the gap 53 between the upper wall 51 and the lower wall 52 in the Y direction, and the first fastening member 63 is inserted into the through hole 611 of the first face material 61 from one side in the Y direction of the load-bearing wall 50. Then, the first face material 61 is brought close to the surface 50a of one side of the load-bearing wall 50 in the Y direction. Furthermore, the first fastening plate 65 (two splicing plates 65) and the second fastening member 64 (round washer 642, hexagonal nut 641) are passed through the first fastening member 63 in order from one side in the Y direction of the first face material 61. In addition, two first fastening members 63 arranged in a direction perpendicular to the paper surface of FIG. 4A (X direction) are inserted into the first face material 61 of this embodiment. For this reason, two splice plates 65 and a second fastening member 64 (642, 641) are provided at one end in the Y direction of each first fastening member 63. Then, a hexagonal nut 641 is screwed onto the threaded portion of the first fastening member 63 for provisional fastening.

As a result, the first panel 61 is installed vertically across the gap 53 between the upper wall 51 and the lower wall 52, and along one surface 51a of the upper wall 51 and one surface 52a of the lower wall 52 in the Y direction (horizontal direction). However, as shown in FIG. 6, the position adjustment bolt 67 attached to the first panel 61 abuts against the wall surface 50a of the load-bearing wall 50, forming a space S (a space S with a width W in the Y direction of, for example, about 5 to 10 mm) between the surface 61b of the first panel 61 and the wall surface 50a of the load-bearing wall 50.

Similarly, the first fastening member 63 protruding from the gap 53 between the upper wall 51 and the lower wall 52 to the other side in the Y direction is inserted into the through hole 621 of the second face material 62. Then, the second face material 62 is brought close to the other side surface 50b of the load-bearing wall 50 in the Y direction. Furthermore, the second attachment plate 66 (two attachment plates 66) and the second fastening member 64 (round washer 642, hexagonal nut 641) are passed through the first fastening member 63 in order from the other side in the Y direction of the second face material 62. In addition, in the second face material 62 of this embodiment, two attachment plates 66 and the second fastening member 64 (642, 641) are provided at the other end of each first fastening member 63 in the Y direction in order to insert two first fastening members 63 aligned in the X direction. Then, the hexagonal nut 641 is screwed into the threaded portion of the first fastening member 63 for temporary fastening.

As a result, the second panel 62 is installed vertically across the gap 53 between the upper wall 51 and the lower wall 52, and along the other surface 51b of the upper wall 51 and the other surface 52b of the lower wall 52 in the Y direction (horizontal direction). However, the position adjustment bolt 67 attached to the second panel 62 abuts against the wall surface 50b of the load-bearing wall 50, forming a space S (a space S with a width W in the Y direction of, for example, about 5 to 10 mm) between the surface 62a of the second panel 62 and the wall surface 50b of the load-bearing wall 50.

During the panel installation process, the second fastening member 64 (hexagonal nut 641) is lightly fastened to the first fastening member 63 so that the panel unit 60 does not shift position relative to the load-bearing wall 50.

<<S05: Pressure bonding process>>
7A and 7B are explanatory diagrams of the filling process of the filler 70, where Fig. 7A is a front view of the bearing wall 50 and the surface material unit 60, and Fig. 7B is a cross-sectional view of the bearing wall 50 and the surface material unit 60. Fig. 8 is a front view of the bearing wall 50 after the pressure bonding process is completed. The pressure bonding process includes a position adjustment process, a filling process of the filler 70, and a tensioning process.

First, a position adjustment process is carried out in which the position adjustment bolts 67 are used to adjust the width W of the space S between the facings 61, 62 and the bearing wall 50. The space S is a space for filling with the filler material 70, and the width W of the space S is adjusted (for example, to about 5 to 10 mm) in order to fill the desired amount of filler material 70.

Specifically, as shown in FIG. 6, the bolt 671 of the position adjustment bolt 67 is in contact with the wall surface of the bearing wall 51 with its tip protruding from the facing materials 61 and 62 by about 5 mm, and nuts 612 and 622 provided on the facing materials 61 and 62 are screwed onto the bolt 671. In addition, a force is applied to the facing materials 61 and 62 to approach the bearing wall 50 by fastening the first fastening member 63 and the second fastening member 64. If the width W of the space S does not reach the desired width (about 5 mm to 10 mm) due to the unevenness of the wall surface of the bearing wall 51, the second fastening member 64 is loosened and the bolt 671 is further rotated to adjust the Y-direction position of the nuts 612 and 622 (i.e., the facing materials 61 and 62) screwed thereto. For example, by rotating the bolt 671 in the tightening direction, the facing materials 61 and 62 are displaced away from the bearing wall 50. This allows the width W of the space S between the face materials 61, 62 and the bearing wall 50 to be adjusted to a desired width. In addition, the anti-loosening nut 672 prevents the nuts 612, 622 (face materials 61, 62) from shifting from the bolt 671, thereby maintaining the width of the space S at a desired width.

Next, as shown in FIG. 7B, a filling process is carried out to fill the space S between the first facing material 61 and the bearing wall 50 (upper wall 51 and lower wall 52) and the space S between the second facing material 62 and the bearing wall 50 (upper wall 51 and lower wall 52) with filler 70. An example of the filler 70 is a cement-based material such as grout.

When filling the filler 70, it is advisable to provide formwork 71 (e.g., backup material, etc.) around the periphery of the space S between the facing materials 61, 62 and the upper wall 51, and around the periphery of the space S between the facing materials 61, 62 and the lower wall 52. This allows the filler 70 to be filled without gaps into the space S between the facing materials 61, 62 and the bearing wall 50 (51, 52), and also prevents the filler 70 from flowing into the gap 53 between the upper wall 51 and the lower wall 52.

After the filler 70 has hardened, a tensioning process is carried out in which the second fastening members 64 (hexagonal nuts 641) fitted to both ends of the two first fastening members 63 inserted through the face materials 61 and 62 are tightened to apply tension to the first fastening members 64. As a result, the first face material 61 and the second face material 62 approach each other in the out-of-plane direction (Y direction) of the load-bearing wall 50, sandwiching the load-bearing wall 50 therebetween, and are pressure-bonded.

The above steps complete the crimping and joining of the surface material unit 60 to the load-bearing wall 50. That is, the first surface material 61 is crimped and joined via the filler 70 to the surface 50a on one side of the load-bearing wall 50 (upper wall 51 and lower wall 52) in the Y direction. The second surface material 62 is crimped and joined via the filler 70 to the surface 50b on the other side of the load-bearing wall 50 (upper wall 51 and lower wall 52) in the Y direction.

In FIG. 8, three panel units 60 are installed on one bearing wall 50 at intervals in the Y direction. However, the number of panel units 60 installed on one bearing wall 50 is not limited to three. In addition, the number of first fastening members 63 inserted into the panel members 61 and 62 may be two or more as in this embodiment in order to suppress the inclination (twist) of the panel members 61 and 62 about the axis of the first fastening members 63. In addition, it is preferable to form through holes 611 and 621 aligned in a direction along the wall surface of the bearing wall 50 (here, the X direction) in the panel members 61 and 62 so that all of the first fastening members 63 inserted into the panel members 61 and 62 pass through the gap 53 between the upper wall 51 and the lower wall 52.

<<S06: Temporary support member installation process>>
9 is an explanatory diagram of the temporary support member installation process, and is a front view of the existing building 1. Next, the temporary support members 80 are installed around the columns 2A, 2B to be worked on, between the superstructure 10 and the substructure 20. In this embodiment, the temporary support members 80 are installed between the column upper reinforcement parts 41 and the column lower reinforcement parts 42 formed around each of the columns 2A, 2B. The temporary support members 80 are used to temporarily support the load of the superstructure 10 after the columns 2 are cut, and are members (e.g., hydraulic jacks) that can be expanded and contracted in the vertical direction.

<S07: Pillar cutting process>
10 is an explanatory diagram of the cutting process of the column 2, and is a front view of the existing building 1. Next, a part of the columns 2A and 2B to be worked on is cut and removed to form an installation space for the seismic isolation device 30. In this embodiment, the part of the columns 2A and 2B between the column upper reinforcement part 41 and the column lower reinforcement part 42 is cut. As a result, the upper structure 10 has the upper part 12 (another upper protruding part) of the column protruding downward from the upper horizontal part 11, and the lower structure 20 has the lower part 22 (another lower protruding part) of the column protruding upward from the lower horizontal part 21. In addition, the load of the upper structure 10 supported by the columns 2A and 2B is transferred to the temporary support member 80.

<S08: Seismic isolation device installation process>
11 is an explanatory diagram of the installation process of the seismic isolation device 30, and is a front view of the existing building 1. In the seismic isolation device installation process, first, the lower foundation 31 is formed on the column lower reinforcement parts 42 of each of the columns 2A, 2B to be constructed. For example, reinforcing bars and formwork (not shown) are assembled according to the shape of the lower foundation 31, and concrete is poured to form the lower foundation 31. At this time, it is preferable to pour the concrete with a base plate (not shown) for installing the seismic isolation device 30 in place.

Next, the seismic isolation device 30 is installed on the lower foundation 31. For example, the lower part of the seismic isolation device 30 is fixed with bolts or the like to a base plate that is integrated with the lower foundation 31. After that, the base plate is installed on the top of the seismic isolation device 30 and fixed with bolts or the like to form the upper foundation 32 that includes the base plate between the seismic isolation device 30 and the upper column reinforcement part 41. As with the lower foundation 31, it is preferable to assemble reinforcing bars and formwork to match the shape of the upper foundation 32, and pour concrete with the base plate as the bottom formwork to form the upper foundation 32.

By installing the seismic isolation device 30 between the upper part 12 of the columns 2A, 2B and the lower part 22 of the columns 2A, 2B in this way, the seismic isolation device 30 can follow the movement of the columns 2. In addition, the seismic isolation device 30 can transmit the load of the upper structure 10 to the lower structure 20 while supporting it.

<S09: Removal process>
12 is a front view of the existing building 1 after the removal process. After the seismic isolation device 30 is installed, the temporary support member 80 is contracted and removed. In this way, the load of the upper structure 10 is temporarily supported. The load of the upper structure 10 is transferred from the member 80 to the seismic isolation device 30. After transferring the load of the upper structure 10 to all the seismic isolation devices 30 of the building and confirming that the seismic isolation structure of the entire building is functioning properly, The surface material unit 60 is also removed. After the removal process, a fire-resistant joint material 54 or the like is provided in the gap 53 between the upper wall 51 and the lower wall 52 to allow the upper structure 10 to be displaced relative to the lower structure 20. If possible, the gap 53 may be filled. Furthermore, a wall 55 is constructed between the column upper reinforcement part 41 and the column lower reinforcement part 42 and the load-bearing wall 50, and a fireproof coating 56 is installed around the seismic isolation device 30. It may also be used as a fire-resistant compartment.

<<About the effectiveness of seismic isolation methods>>
Fig. 13 is a schematic plan view of the existing building 1. Fig. 14A and Fig. 14B are explanatory diagrams of a comparative example of a seismic isolation method different from this embodiment.
5A, in the seismic isolation method of the present embodiment, the first surface material 61 is installed so as to straddle the gap 53 between the upper wall 51 and the lower wall 52 in the vertical direction and along one surface 51a of the upper wall 51 and one surface 52a of the lower wall 52 in the Y direction (horizontal direction). In addition, the second surface material 62 is installed so as to straddle the gap 53 between the upper wall 51 and the lower wall 52 in the vertical direction and along the other surface 51b of the upper wall 51 and the other surface 52b of the lower wall 52 in the Y direction (horizontal direction).

Then, the first and second fastening members 63 are inserted in the Y direction (horizontal direction) through the through-holes 611 of the first panel 61, the gaps 53 between the upper and lower walls 51 and 52, and the through-holes 621 of the second panel 62, and the second fastening members 64 are screwed into the first and second fastening members 63. Therefore, during construction of the seismic isolation method of this embodiment, the seismic isolation structure (seismic isolated structure) shown in FIG. 11 is formed, allowing safe construction.

In other words, the frictional force between the facings 61, 62 and the bearing wall 50 (upper wall 51 and lower wall 51) generated by the tension of the first fastening member 63 restrains and fixes the upper wall 51 and the lower wall 52 to each other. In this state, a part of the column 2 is cut, and the seismic isolation device 30 is installed at the cut site. Therefore, even if an earthquake or storm occurs during construction while the column 2 etc. is cut, the frictional force between the facings 61, 62 and the bearing wall 50 maintains the resistance to horizontal external forces acting on the building in the X direction (the direction along the wall surface, the direction perpendicular to the horizontal Y direction) and construction can be carried out safely.

Specifically, when a horizontal external force in the X direction acts on the upper wall 51, the horizontal external force is transmitted to the lower wall 52 by the frictional force between the facings 61, 62 and the load-bearing wall 50. Therefore, the movement (displacement) in the X direction of the upper wall 51 (upper structure 10) relative to the lower wall 52 (lower structure 20) is restricted, allowing safe construction.

In addition, in the seismic isolation method of this embodiment, the bearing wall 50 is cut into a side connected to the upper structure 10 and a side connected to the lower structure 20 so that the seismic isolation device 30 can function, and the first fastening member 63 is inserted into the gap 53 formed at that time. Therefore, construction is easier than when a seismic plate 91 (surface material in this embodiment) is installed, as in the comparative example shown in Figures 14A and 14B.

For example, in this embodiment, there is no need to form through holes 93 in the upper wall 51 and the lower wall 52 just for inserting the fastening member 92, as in the comparative example. Also, in this embodiment, there is no need to backfill the through holes 93 after removing the earthquake-resistant plate 92 (face material), as in the comparative example. Also, in this embodiment, since the through holes 93 are not formed in the upper wall 51 and the lower wall 52 as in the comparative example, there is no risk of damaging the reinforcing bars embedded in the upper wall 51 and the lower wall 52 when forming the through holes 93. Conversely, in this embodiment, there is no need to perform reinforcing bar inspection of the upper wall 51 and the lower wall 52 before forming the through holes 93, which saves construction work.

In this way, according to the seismic isolation method of this embodiment, the panel units 60 are installed on the load-bearing walls 50 separated into upper and lower parts, so that the load-bearing strength against horizontal external forces acting on the building during construction is maintained and construction can be carried out safely. In addition, compared to the comparative example, the installation of the panel units 60 is less time-consuming, making it easier to carry out seismic isolation construction work. As a result, the construction period can be shortened and construction costs can be reduced. In addition, since no through holes for installing the panel units 60 are formed in the load-bearing walls 50, damage to the load-bearing walls 50 and the reinforcing bars embedded in the load-bearing walls 50 can be reduced.

So far, we have taken the example of installing the panel unit 60 on a bearing wall 50 that has a wall surface along the X direction. However, the panel unit 60 of this embodiment can also be installed on a bearing wall 50 (upper protrusion and lower protrusion) that has a wall surface along the horizontal direction that intersects with the X direction.

For example, as shown in FIG. 13, a surface material unit 60 (60Y) can be installed on a bearing wall 50 (50Y) having a wall surface along the Y direction perpendicular to the X direction. This surface material unit 60 (60Y) can suppress misalignment of the upper structure 10 in the Y direction relative to the lower structure 20 even during construction when columns 2, etc. are cut. As shown in FIG. 13, by installing surface material units 60 on the bearing walls 50 along the X direction and Y direction, respectively, misalignment of the upper structure 10 in the X direction and Y direction can be suppressed.

In addition, it is not necessary to install the surface material units 60 on all the cut bearing walls 50, and it is also possible not to install the surface material units 60 on some of the cut bearing walls 50 as long as the construction can be carried out safely. In general, when the strength of the opposing member in the X direction (e.g., the bearing wall 50X on which the surface material units 60X are installed) and the opposing member in the Y direction (e.g., the bearing wall 50Y on which the surface material units 60Y are installed) are about the same, it is advisable to install the same number of opposing members in the X direction and the Y direction. In addition, although not shown, brace materials may be arranged between the columns to increase the horizontal strength during construction by using the surface material units 60 and the brace materials together.

In addition, in the seismic isolation method of this embodiment, seismic isolation devices 30 are installed on multiple columns 2 on the construction floor, and the seismic isolation device installation process of installing the seismic isolation devices 30 on the columns 2 is performed multiple times. Therefore, it is advisable to perform the panel installation process and the pressure bonding process before at least one of the multiple seismic isolation device installation processes. In this way, the seismic isolation device installation process (and the column cutting process) can be safely performed by the load-bearing wall 50 on which the panel unit 60 is installed.

In addition, in this embodiment, before the panel installation process, a gap formation process is carried out in which the load-bearing wall 50 (wall) extending vertically between the upper horizontal section 11 and the lower horizontal section 21 of the existing building 1 is cut to separate it into an upper wall 51 and a lower wall 52, and a gap 53 through which the first fastening member 63 is inserted is formed.

Therefore, the gap 53 formed when the existing bearing wall 50 is cut can be used to install the panel unit 60, and seismic isolation work can be carried out efficiently. In addition, before cutting the columns 2, etc. to install the seismic isolation device 30, the existing bearing wall 50 (wall) that was originally equipped on the existing building 1 can be cut. This allows for efficient seismic isolation work. For example, if the wall has been cut, the installation of the seismic isolation devices 30 for the entire building can be completed, and after it has been confirmed that the seismic isolation structure is functioning properly, the seismic isolation function of the building can be demonstrated in a short period of time.

In this embodiment, the surface material unit 60 is installed on the existing load-bearing wall 50 (wall) that the existing building 1 originally had, but this is not limited to this. The surface material unit 60 may also be installed on a wall newly constructed during seismic isolation work (an upper wall and a lower wall that were originally constructed in a separate state). In addition, the wall on which the surface material unit 60 is installed is not limited to a load-bearing wall (e.g. a reinforced concrete wall, etc.), and may be any wall that functions as a horizontal counterweight by installing the surface material unit 60 after cutting.

In addition, in this embodiment, in the pressure bonding process, as shown in FIG. 4A, the first attachment plate 65 is attached to the surface 61a on one side of the first surface material 61 in the Y direction, and the second attachment plate 66 is attached to the surface 62b on the other side of the second surface material 62 in the Y direction, and then the first surface material 61 and the second surface material 62 are pressure bonded to the upper wall 51 and the lower wall 52.

Therefore, the tension of the first fastening member 63 caused by tightening the second fastening member 64 (hexagonal nut 641) can be distributed and applied over a wide range of the face materials 61, 62 via the first and second attachment plates 65, 66. In other words, the tension of the first fastening member 63 can be prevented from acting locally on parts of the face materials 61, 62, causing deformation of the face materials 61, 62. As a result, the face materials 61, 62 can be pressure-bonded to the wall surface of the bearing wall 50 over a wide range, increasing the frictional force between the face materials 61, 62 and the bearing wall 50. This increases the resistance of the bearing wall 50 to horizontal external forces on which the face material unit 60 is installed.

The tension of the first fastening member 63 acts on a range extending diagonally from the fastening position of the second fastening member 64 (the contact surface between the second fastening member 64 and the first attachment plate 65 or the second attachment plate 66) to the horizontal direction. Therefore, as in this embodiment, it is preferable to use thick square washers as the first attachment plate 65 and the second attachment plate 66, and to increase the horizontal distance (here, the Y direction) from the fastening position of the second fastening member 64 to the face materials 61, 62. By doing so, the tension of the first fastening member 63 acts on a wider range of the face materials 61, 62. Therefore, the face materials 61, 62 can be firmly pressure-bonded to the wall surface of the bearing wall 50, the frictional force between the face materials 61, 62 and the bearing wall 50 is increased, and the resistance to horizontal external forces of the bearing wall 50 on which the face material unit 60 is installed is increased.

In this embodiment, a first pressing plate 65 pressed against the first surface material 61 and a second surface material 62 are provided.
The second splice plate 66 that is spliced to the first splice plate 65 is formed by stacking a plurality of splice plates 65, 66 (two square washers in this example) in the horizontal direction.

By doing so, the horizontal distance from the tightening position of the second fastening member 64 to the panel members 61, 62 is increased, and the tension of the first fastening member 63 acts over a wider area of the panel members 61, 62. This allows the panel members 61, 62 to be firmly pressure-bonded to the wall surface of the bearing wall 50, increasing the friction between the panel members 61, 62 and the bearing wall 50, and increasing the resistance of the bearing wall 50 to horizontal external forces on which the panel unit 60 is installed.

However, this is not limited to the above. For example, the first and second attachment plates 65 and 66 may be thin members (washers), a single member (washer), or three or more members (washers) stacked together.

The pressure bonding process of this embodiment also includes a filling process in which a filler 70 is filled between the first surface material 61 and the upper wall 51 and the lower wall 52, and between the second surface material 62 and the upper wall 51 and the lower wall 52.

As a result, the facing materials 61, 62 can be tightly attached to the bearing wall 50 via the filler 70, and can be firmly pressure-bonded to the wall surface of the bearing wall 50. This increases the friction between the facing materials 61, 62 and the bearing wall 50, and increases the resistance of the bearing wall 50 to horizontal external forces on which the facing unit 60 is installed.

In addition, the seismic isolation method of this embodiment includes a roughening process for the bearing wall 50 before the face material installation process. The roughening process makes the surface of the bearing wall 50 uneven, which increases the adhesion strength of the filler material 70 to the bearing wall 50. Therefore, the facing materials 61 and 62 can be firmly pressure-bonded to the bearing wall 50 via the filler material 70.

Furthermore, after the roughening process, the facings 61, 62 are installed, and a water absorption adjustment material (e.g., Refretreat manufactured by Sumitomo Osaka Cement Co., Ltd.) may be applied to the area of the bearing wall 50 to which the filler 70 is applied. This can further increase the adhesion strength of the filler 70 to the bearing wall 50.

However, this is not limited to the above, and the facing materials 61, 62 may be directly pressure-bonded to the bearing wall 50 without filling the filler 70 between the facing materials 61, 62 and the bearing wall 50. Also, the roughening process may not be performed.

The seismic isolation device 30 of this embodiment is installed in a location (the cut location of the column 2) different from the bearing wall 50 on which the panel unit 60 is installed. In this case, the vertical length H1 (FIG. 3B) of the gap 53 between the upper wall 51 and the lower wall 52 is preferably shorter than the vertical length H2 (FIG. 11) of the seismic isolation device 30. Preferably, the vertical length H1 of the gap 53 is 70 mm or less.

By doing so, the tension of the first fastening member 63 inserted into the gap 53 can be received by the load-bearing wall 50 rather than by the space of the gap 53. This allows frictional force to be efficiently generated between the facing materials 61, 62 and the load-bearing wall 50, and also suppresses bending of the facing materials 61, 62. In addition, the size and thickness of the facing materials 61, 62 can be reduced, which reduces construction costs.

The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the scope of the present invention. The present invention may be modified or improved without departing from the spirit of the invention, and it goes without saying that the present invention includes equivalents.

1 Existing building, 2 Pillars, 3 Beams,
10 Upper structure, 11 Upper horizontal part, 12 Upper part of the column (other upper protruding part),
20 Lower structure, 21 Lower horizontal part, 22 Lower part of the column (other lower protruding part),
30 seismic isolation device, 31 lower foundation, 32 upper foundation,
41: Upper column reinforcement part; 42: Lower column reinforcement part;
50 load-bearing wall, 51 upper wall (upper protrusion), 52 lower wall (lower protrusion),
53 gap, 54 joint material, 55 wall, 56 fireproof coating,
60 surface material unit, 61 first surface material, 62 second surface material,
63 First fastening member, 64 Second fastening member,
65 First splice plate, 66 Second splice plate, 67 Position adjustment bolt,
70 Filling material, 71 Formwork,
80 Temporary support member,
91 earthquake-resistant plate, 92 fastening member, 93 through hole,

Claims (7)

A seismic isolation method in which a seismic isolation device is installed between an upper structure and a lower structure,
The upper structure has an upper horizontal portion and an upper protruding portion protruding downward from the upper horizontal portion,
The lower structure has a lower horizontal portion and a lower protruding portion protruding upward from the lower horizontal portion,
a surface material installation process for installing a first surface material so as to straddle a gap between the upper protrusion and the lower protrusion in a vertical direction and along one side surface of the upper protrusion and the one side surface of the lower protrusion in a horizontal direction, and installing a second surface material so as to straddle the gap in the vertical direction and along the other side surface of the upper protrusion and the other side surface of the lower protrusion in the horizontal direction;
a pressure-bonding process in which the first face material and the second face material are pressure-bonded to the upper protrusion and the lower protrusion by a first fastening member inserted along the horizontal direction into a through hole and the gap of the first face material and a through hole of the second face material, and a second fastening member screwed into the first fastening member;
a seismic isolation device installation process for installing the seismic isolation device between the upper structure and the lower structure after the pressure bonding process;
A seismic isolation method comprising the steps of: The seismic isolation method according to claim 1,
In the pressure bonding step, a first bonding plate is bonded to the one side surface of the first face material in the horizontal direction, and a second bonding plate is bonded to the other side surface of the second face material in the horizontal direction.
A seismic isolation method characterized in that the first panel and the second panel are pressure-bonded to the upper protrusion and the lower protrusion with a splice plate attached. The seismic isolation method according to claim 2,
A seismic isolation method characterized in that the first attachment plate and the second attachment plate are constructed by stacking a plurality of attachment plates in the horizontal direction. The seismic isolation method according to any one of claims 1 to 3,
This is a seismic isolation method characterized in that the pressure bonding process includes a filling process of filling a filler between the first surface material and the upper protrusion and the lower protrusion, and between the second surface material and the upper protrusion and the lower protrusion. The seismic isolation method according to any one of claims 1 to 4,
the upper protrusion and the lower protrusion are walls extending in the vertical direction between the upper horizontal portion and the lower horizontal portion,
A seismic isolation method characterized by including a gap forming process, which, prior to the panel installation process, cuts the wall to separate it into the upper protrusion and the lower protrusion, and forms the gap. The seismic isolation method according to any one of claims 1 to 5,
The upper structure has another upper protruding portion protruding downward from the upper horizontal portion,
the lower structure has another lower protruding portion protruding upward from the lower horizontal portion,
In the seismic isolation device installation step, the seismic isolation device is installed between the other upper protruding portion and the other lower protruding portion,
A seismic isolation method, characterized in that the length of the gap in the vertical direction is shorter than the length of the seismic isolation device in the vertical direction. an upper structure having an upper horizontal portion and an upper protruding portion protruding downward from the upper horizontal portion;
a lower structure having a lower horizontal portion and a lower protruding portion protruding upward from the lower horizontal portion;
A seismic isolation device installed between the upper structure and the lower structure;
A seismic isolation structure having
A first surface material that vertically spans the gap between the upper protrusion and the lower protrusion and is installed along one side surface of the upper protrusion and one side surface of the lower protrusion in the horizontal direction;
a second surface member that spans the gap in the vertical direction and is installed along the other surface of the upper protrusion and the other surface of the lower protrusion in the horizontal direction;
a first fastening member that crimps and joins the first face material and the second face material to the upper protrusion and the lower protrusion;
a second fastening member that is screwed into the first fastening member;
having
A seismic isolation structure characterized in that the first fastening member is inserted along the horizontal direction through a through hole provided in the first panel, the gap, and a through hole provided in the second panel.

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