Base isolation chemical method and base isolation structure

Abstract

To safely perform construction by enhancing a strength against a horizontal external force acting on a building under construction while facilitating the construction of seismic isolation work.SOLUTION: There is provided a seismic isolation method in which a seismic isolation device is provided between an upper structure and a lower structure. The upper structure has: an upper horizontal portion; a first upper protruding portion that protrudes downward from the upper horizontal portion and is arranged at an interval in a first direction; and a second upper protruding portion. The lower structure has: a lower horizontal portion; a first lower protruding portion that protrudes upward from the lower horizontal portion and is arranged at an interval in the first direction; and a second lower protruding portion. Between the first upper protruding portion and the second upper protruding portion, and between the first lower protruding portion and the second lower protruding portion, there is provided a horizontal competition member installation step of installing a horizontal competition member that opposes a horizontal force in the first direction along the first direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a seismic isolation construction method and a seismic isolated structure.

Background Art

[0002] There is a seismic isolation construction method in which columns of an existing building are cut and a seismic isolation device is installed at the cut portion for seismic isolation. In Patent Document 1, in order to increase the load-bearing capacity against an earthquake (horizontal external force) acting on a building during seismic isolation construction, before cutting the columns, X-shaped braces or K-shaped braces are installed as temporary braces in the openings between the columns. By doing so, the construction safety is improved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when an inclined opposing member is installed in the opening between columns as in Patent Document 1, when a horizontal external force acts on the building, bending or buckling may occur in the opposing member. Therefore, there are problems such that the load-bearing capacity against the horizontal external force is not sufficient, or an unnecessarily large number of opposing members have to be installed. In addition, when an inclined opposing member is installed, a large number of anchors are driven into columns, beams, floors, etc. of the existing building to attach gusset plates, and an inclined opposing member is arranged between the gusset plates, etc., and the construction becomes relatively complicated.

[0005] The present invention has been made in view of such problems, and an object thereof is to facilitate the construction of seismic isolation construction work, and to increase the load-bearing capacity against the horizontal external force acting on the building during construction and perform the construction safely.

Means for Solving the Problems

[0006] To achieve such an object, the seismic isolation chemical construction method of the present invention is a seismic isolation chemical construction method in which a seismic isolation device is provided between an upper structure and a lower structure, wherein the upper structure has an upper horizontal part, a first upper protruding part protruding downward from the upper horizontal part and arranged at intervals in a first direction, and a second upper protruding part, the lower structure has a lower horizontal part, a first lower protruding part protruding upward from the lower horizontal part and arranged at intervals in the first direction, and a second lower protruding part, and a horizontal counter member installation step of installing a horizontal counter member that resists the horizontal force in the first direction along the first direction between the first upper protruding part and the second upper protruding part and between the first lower protruding part and the second lower protruding part, A seismic isolation device installation step is provided, in which a first seismic isolation device is installed between the first upper protruding portion and the first lower protruding portion, and a second seismic isolation device is installed between the second upper protruding portion and the second lower protruding portion. After the seismic isolation device installation step, a horizontal countermeasure member installation step is provided. After the horizontal countermeasure member installation step, a protruding portion forming step is provided, in which a part of a column extending from the lower horizontal portion to the upper horizontal portion is cut, and a third upper protruding portion that is the upper part of the column and protrudes downward from the upper horizontal portion, and a third lower protruding portion that is the lower part of the column and protrudes upward from the lower horizontal portion are formed. After the protruding portion forming step, another seismic isolation device installation step is provided, in which a third seismic isolation device is installed between the third upper protruding portion and the third lower protruding portion. which is characterized by the above.

[0007] According to such a seismic isolation chemical construction method, the horizontal external force acting on the upper structure can be transmitted to the lower structure via the horizontal counter member, the displacement of the upper structure with respect to the lower structure can be suppressed, and construction can be carried out safely. In addition, the horizontal counter member can be easily installed along the first direction. Further, bending and buckling are less likely to occur in the horizontal counter member, the strength of the building against horizontal external forces can be increased, and construction can be carried out safely. Moreover, the step of cutting a column at another location and installing a third seismic isolation device by a horizontal countermeasure member installed near the first seismic isolation device and the second seismic isolation device can be safely implemented.

[0008] Such a seismic isolation chemical construction method, wherein the horizontal counter member has an upper counter member and a lower counter member, and in the horizontal counter member installation step, the upper counter member is installed along the first direction between the first upper protruding part and the second upper protruding part, and the lower counter member is installed along the first direction between the first lower protruding part and the second lower protruding part, and the upper counter member and the lower counter member are connected, which is characterized by the above.

[0009] According to such a seismic isolation construction method, even when the vertical distance between the first upper protruding portion and the first lower protruding portion is large, a horizontal counter member can be installed. Also, the upper counter member and the lower counter member can be easily installed along the first direction. Further, bending and buckling are less likely to occur in the upper counter member and the lower counter member, the bearing capacity of the building against horizontal external forces can be increased, and construction can be carried out safely.

[0010] Such a seismic isolation construction method, in the horizontal counter member installation step, The upper countermeasure member and the lower countermeasure member along the first direction Between the upper countermeasure member and the lower countermeasure member is characterized by connecting through a connecting member installed.

[0011] According to such a seismic isolation construction method, even when the vertical distance between the first upper protruding portion and the first lower protruding portion is large, a horizontal counter member can be installed. Also, the connecting member can be easily installed along the first direction. Further, bending and buckling are less likely to occur in the connecting member, and horizontal external forces can be efficiently transmitted through the connecting member.

[0012] Such a seismic isolation construction method, in the horizontal counter member installation step, is characterized by filling a filler between at least one side surface of the first upper protruding portion and the second upper protruding portion and the surface of the horizontal counter member facing the side surface.

[0013] According to such a seismic isolation construction method, the horizontal counter member can be brought into surface contact with the side surfaces of the first upper protruding portion and the second upper protruding portion, and it is possible to prevent the occurrence of locations where force is locally applied.

[0014] Such a seismic isolation construction method, in the horizontal counter member installation step, is characterized by filling a filler between at least one side surface of the first lower protruding portion and the second lower protruding portion and the surface of the horizontal counter member facing the side surface.

[0015] According to such a seismic isolation construction method, the horizontal counter member can be brought into surface contact with the side surfaces of the first lower protruding portion and the second lower protruding portion, and it is possible to prevent the occurrence of locations where force is locally applied.

[0016] In such a seismic isolation construction method, a first seismic isolation device is installed between the first upper protruding portion and the first lower protruding portion, and a second seismic isolation device is installed between the second upper protruding portion and the second lower protruding portion after the horizontal countermember installation step. It is characterized by having a seismic isolation device installation step.

[0017] According to such a seismic isolation construction method, since the horizontal countermember is installed near the location where the space for installing the seismic isolation device is formed (for example, the location where the column is cut), the displacement of the upper structure relative to the lower structure can be more reliably suppressed, and construction can be carried out safely.

[0018] In such a seismic isolation construction method, the first upper protruding portion and the second upper protruding portion each have an upper part of a column and a column upper reinforcement part where concrete is placed outside the upper part of the column. The first lower protruding portion and the second lower protruding portion each have a lower part of a column and a column lower reinforcement part where concrete is placed outside the lower part of the column. Before the seismic isolation device installation step, a temporary support member installation step of installing a temporary support member for temporarily receiving the load of the upper structure is provided between the first upper protruding portion and the first lower protruding portion, and between the second upper protruding portion and the second lower protruding portion, respectively. Before the horizontal countermember installation step and the temporary support member installation step, a reinforcement part forming step of forming the column upper reinforcement part and the column lower reinforcement part is provided. In the horizontal countermember installation step, the horizontal countermember is brought into contact with the side surfaces of the column upper reinforcement part and the column lower reinforcement part. In the temporary support member installation step, the temporary support member is brought into contact with the lower surface of the column upper reinforcement part and the upper surface of the column lower reinforcement part. It is characterized by this.

[0019] According to such a seismic isolation construction method, the horizontal external force acting on the upper structure can be transmitted to the lower structure through the horizontal countermember, and the displacement of the upper structure relative to the lower structure can be suppressed. Also, the load of the upper structure can be supported by the temporary support member and transmitted to the lower structure.

[0022] Such a seismic isolation construction method, wherein the first upper protruding portion has a first upper foundation installed on the first seismic isolation device, the first lower protruding portion has a first lower foundation installed under the first seismic isolation device, the second upper protruding portion has a second upper foundation installed on the second seismic isolation device, the second lower protruding portion has a second lower foundation installed under the second seismic isolation device, and in the seismic isolation device installation step, the first lower foundation is formed, after the first seismic isolation device is installed on the first lower foundation, the first upper foundation is formed, and the second lower foundation is formed, after the second seismic isolation device is installed on the second lower foundation, the second upper foundation is formed, and in the horizontal countermeasure member installation step, the horizontal countermeasure member is abutted against the side surface of the first upper foundation, the side surface of the first lower foundation, the side surface of the second upper foundation, and the side surface of the second lower foundation. A seismic isolation construction method characterized by this.

[0023] According to such a seismic isolation construction method, since the vertical distance between the upper foundation and the lower foundation of the seismic isolation device is relatively small, the number of horizontal countermeasure members can be reduced, or the number of connecting members can be reduced, and the construction can be facilitated.

[0024] Such a seismic isolation construction method, characterized in that in the horizontal countermeasure member installation step, a support member for supporting the horizontal countermeasure member from below is installed, or the horizontal countermeasure member is suspended from above.

[0025] According to such a seismic isolation construction method, the deflection due to the self-weight of the horizontal countermeasure member can be suppressed. Since the support member is removed after construction, an effective space during the construction stage is ensured.

[0026] Further, a seismic isolation structure having a seismic isolation device between an upper structure and a lower structure, an upper structure having an upper horizontal portion, a first upper protruding portion protruding downward from the upper horizontal portion and arranged at intervals in a first direction, and a second upper protruding portion, a lower structure having a lower horizontal portion, a first lower protruding portion protruding upward from the lower horizontal portion and arranged at intervals in the first direction, and a second lower protruding portion. Between the first upper protruding portion and the second upper protruding portion, and between the first lower protruding portion and the second lower protruding portion, a horizontal resistance member is installed along the first direction to resist the horizontal force in the first direction. A seismic isolation structure characterized by comprising the above.

[0027] According to such a seismic isolation structure, the horizontal external force acting on the superstructure can be transmitted to the substructure through the horizontal resistance member, the displacement of the superstructure relative to the substructure can be suppressed, and construction can be carried out safely. In addition, the horizontal resistance member can be easily installed along the first direction. Further, bending and buckling are less likely to occur in the horizontal resistance member, the load-bearing capacity of the building against the horizontal external force can be increased, and construction can be carried out safely. Note that such a seismic isolation structure (seismic isolated structure) includes the structure in the intermediate process in the seismic isolation construction method.

Effect of the Invention

[0028] According to the present invention, while facilitating the construction of the seismic isolation work, the load-bearing capacity against the horizontal external force acting on the building during construction can be increased, and construction can be carried out safely.

Brief Description of the Drawings

[0029]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. ===First Embodiment=== <<S01: Reinforcement Part Formation Step>> Fig. 1 is a flowchart showing the procedure of the seismic isolation construction method of the first embodiment. Fig. 2 is an explanatory view of the reinforcement part formation step, and Fig. 2 is a front view of the reinforced existing building 1.

[0031] In the seismic isolation construction method of the first embodiment, the existing building 1 is separated into an upper structure 10 and a lower structure 20, and a seismic isolation device 30 (for example, a laminated rubber type, a rolling bearing type, a sliding bearing type, etc.) is installed therebetween. Specifically, a part of the column 2 on the intermediate floor of the existing building 1 is cut (here, a part of the column 2 extending in the vertical direction from the floor surface FL1 of the first floor to the floor surface FL2 of the second floor is cut), and the seismic isolation device 30 is installed at the cutting location. In the first embodiment, as shown in Fig. 6 described later, two columns 2A and 2B arranged at intervals in the X direction (horizontal direction, first direction) are used as the columns for installing the seismic isolation device 30.

[0032] First, in order to compensate for the reduction in the strength and rigidity of the existing building 1 caused by separating the existing building 1 vertically, a reinforcing portion 40 is formed to reinforce the existing building 1. For example, concrete is placed to raise the floor surface of the floor where the seismic isolation device 30 is installed, thicken the columns 2, or thicken the beams 3. In FIG. 2, the portion with diagonal lines in the lower right is taken as the reinforcing portion 40. However, if there is no need to reinforce the existing building 1, the reinforcing portion forming process is unnecessary.

[0033] In the first embodiment, at least, a column upper reinforcing portion 41 in which concrete is placed and reinforced on the outer side of the upper portions of the columns 2A and 2B to be constructed, and a column lower reinforcing portion 42 in which concrete is placed and reinforced on the outer side of the lower portions of the columns 2A and 2B to be constructed are formed.

[0034] Also, the portion of the existing building 1 above the installation position of the seismic isolation device 30 is defined as the upper structure 10, and the portion of the existing building 1 below the installation position of the seismic isolation device 30 is defined as the lower structure 20. The upper structure 10 has an upper horizontal portion 11 (the portion above the lower surface of the reinforcing portion 40 of the beam 3), and a first upper protruding portion 12 and a second upper protruding portion 13 that protrude downward from the upper horizontal portion 11 and are arranged at intervals in the X direction. The first upper protruding portion 12 and the second upper protruding portion 13 each have an upper portion of the column 2 and a column upper reinforcing portion 41 (a part thereof) in which concrete is placed on the outer side of the upper portion of the column 2.

[0035] The lower structure 20 has a lower horizontal portion 21 (the portion below the reinforced floor surface FL2), and a first lower protruding portion 22 and a second lower protruding portion 23 that protrude upward from the lower horizontal portion 21 and are arranged at intervals in the X direction. The first lower protruding portion 22 and the second lower protruding portion 23 each have a lower portion of the column 2 and a column lower reinforcing portion 42 in which concrete is placed on the outer side of the lower portion of the column 2.

[0036] In addition, when forming the upper column reinforcement part 41 and the lower column reinforcement part 42, the joint 43 when installing the seismic isolation device 30 may be embedded in the upper column reinforcement part 41 and the lower column reinforcement part 42 in advance. Further, PC steel bars 44 may be inserted through the upper part of the upper column reinforcement part 41 and the columns 2A and 2B, and both ends of the PC steel bars 44 may be fastened with nuts to apply prestress, thereby increasing the tensile strength of the upper column reinforcement part 41.

[0037] <<S02: Temporary support member installation process and horizontal countermeasure member installation process>> FIGS. 3A and 3B are explanatory views of the temporary support member installation process and the horizontal countermeasure member installation process. FIG. 3A is a front view of the existing building 1, and FIG. 3B is a schematic plan view of the existing building 1 seen from above. FIGS. 4A to 4C are explanatory views of the horizontal countermeasure member group 60. FIG. 4A is a front view of the horizontal countermeasure member group 60, FIG. 4B is a side view of the horizontal countermeasure member group 60 seen from one side in the X direction, and FIG. 4C is a plan view of the horizontal countermeasure member group 60 seen from above.

[0038] Next, a temporary support member installation process of installing temporary support members 50 around the columns 2A and 2B to be constructed is carried out. That is, temporary support members 50 are installed between the first upper protruding part 12 (upper column reinforcement part 41A) and the first lower protruding part 22 (lower column reinforcement part 42A), and between the second upper protruding part 13 (upper column reinforcement part 41B) and the second lower protruding part 23 (lower column reinforcement part 42B), respectively. The temporary support member 50 is for temporarily receiving the load of the upper structure 10 after the column 2 is cut, and is a member that can expand and contract in the vertical direction (for example, a hydraulic jack, etc.).

[0039] After installing the temporary support members 50 on the lower column reinforcement parts 42A and 42B, the temporary support members 50 are extended upward in the vertical direction to the upper column reinforcement parts 41A and 41B. Then, the temporary support members 50 are brought into contact with the lower surfaces of the upper column reinforcement parts 41A and 41B and the upper surfaces of the lower column reinforcement parts 42A and 42B. By doing so, after the column 2 is cut, the load of the upper structure 10 is transmitted to the lower structure 20 while being supported by the temporary support members 50. In addition, in FIG. 3B, the number of temporary support members 50 installed for one column 2 is four, but it is not limited to this.

[0040] Next, a horizontal countermeasure member installation step of installing a group of horizontal countermeasure members 60 in the space between the columns 2A and 2B to be constructed is carried out. The group of horizontal countermeasure members 60 is a member for countering the horizontal force in the X direction acting on the existing building 1. The group of horizontal countermeasure members 60 in the first embodiment includes an upper countermeasure member 61 and a lower countermeasure member 62 which are horizontal countermeasure members, a connecting member 63, and a support member 64. Here, rafter retaining members 611, 621 and piece members 612, 622 are used as the upper countermeasure member 61 and the lower countermeasure member 62 respectively, a rafter retaining member is used as the connecting member 63, and a piece member is used as the support member 64.

[0041] The rafter retaining member (for example, the rafter retaining member 611) is a steel material with both ends of the H-beam blocked by end plates, and can be exemplified by having a pair of flanges (611A), a web (611B), a pair of end plates (611C), an auxiliary plate (611D) having a substantially triangular shape fixed to the web, and a through hole (611E) for inserting a fastener such as a bolt. The piece member is a member with a shorter length than the rafter retaining member, and like the rafter retaining member, can be exemplified by having a pair of flanges, a web, a pair of end plates, an auxiliary plate, and a through hole. The upper countermeasure member 61 and the lower countermeasure member 62 in the present embodiment are members in which the rafter retaining members 611, 621 and the piece members 612, 622 are joined by bolts or the like with their end plates in contact with each other.

[0042] Then, as shown in FIG. 3A, between the first upper protruding portion 12 and the second upper protruding portion 13, and also between the first lower protruding portion 22 and the second lower protruding portion 23, horizontal countermeasure members (upper countermeasure member 61 and lower countermeasure member 62) are installed horizontally or substantially horizontally along the X direction. In the first embodiment, the upper countermeasure member 61 is installed between the first upper protruding portion 12 and the second upper protruding portion 13 (between the column upper reinforcing portions 41A, 41B) so that its longitudinal direction is along the X direction. Also, the lower countermeasure member 62 is installed between the first lower protruding portion 22 and the second lower protruding portion 23 (between the column lower reinforcing portions 42A, 42B) so that its longitudinal direction is along the X direction.

[0043] Specifically, the end face 61a on one side in the X direction of the upper opposing member 61 (the end plate 611C of the ridge retaining member 611) is brought into contact with the side face 12a of the first upper protruding portion 12 (the column upper reinforcing portion 41A), and the end face 61b on the other side in the X direction of the upper opposing member 61 (the end plate of the piece member 612) is brought into contact with the side face 13a of the second upper protruding portion 13 (the column upper reinforcing portion 41B).

[0044] Similarly, the end face 62a on one side in the X direction of the lower opposing member 62 (the end plate of the ridge retaining member 621) is brought into contact with the side face 22a of the first lower protruding portion 22 (the column lower reinforcing portion 42A), and the end face 62b on the other side in the X direction of the lower opposing member 62 (the end plate of the piece member 622) is brought into contact with the side face of the second lower protruding portion 23 (the column lower reinforcing portion 42B).

[0045] However, in this embodiment, a filling material 65 (for example, grout material, etc.) is filled between the end face 61b on the other side in the X direction of the upper opposing member 61 and the side face 13a of the second upper protruding portion 13. In this case, the end face 61b on the other side in the X direction of the upper opposing member 61 abuts against the side face 13a of the second upper protruding portion 13 via the filling material 65. Similarly, in this embodiment, a filling material 65 is filled between the end face 62b on the other side in the X direction of the lower opposing member 62 and the side face 23a of the second lower protruding portion 23. In this case, the end face 62b on the other side in the X direction of the lower opposing member 62 abuts against the side face 23a of the second lower protruding portion 23 via the filling material 65.

[0046] Also, in the first embodiment, the upper opposing member 61 and the lower opposing member 62 are connected via three connecting members 63. Each connecting member 63 (ridge retaining member) is also installed horizontally or substantially horizontally so that its longitudinal direction is along the X direction. Specifically, the vertically adjacent ridge retaining members (the upper opposing member 61 and the topmost connecting member 63, the second and third connecting members 63 from the top, the third connecting member 63 from the top and the lower opposing member 62) are joined with bolts 66, nuts 67, and washer plates 68 in a state where their flange faces are in contact with each other. Or, it may be a friction joint or a bearing joint.

[0047] Furthermore, a support member 64 (piece material) that supports the upper counter member 61, the connection member 63, and the lower counter member 62 from below is installed. In the first embodiment, three support members 64 joined vertically are installed below both ends in the X direction of the lower counter member 62 (the ridge retaining member 621). Specifically, with the flange of the lower counter member 62 (the ridge retaining member 621) and the end plate of the support member 64 in contact, the lower counter member 62 and the support member 64 are joined with bolts or the like. Also, instead of the support member 64, the upper counter member 61, the connection member 63, or the lower counter member 62 may be suspended from above (for example, from the upper horizontal part 11 such as a beam 3) with a wire or the like.

[0048] Note that for the horizontal counter member group 60, any of its constituent members 61 to 64 may be installed first, or the constituent members 61 to 64 may be joined first and then installed. Also, for the temporary support member installation process and the horizontal counter member installation process, either may be performed first or they may be performed simultaneously.

[0049] <S03: Column Cutting Process> FIG. 5 is an explanatory diagram of the column cutting process and is a front view of the existing building 1. Next, a part of the columns 2A and 2B to be constructed is cut and removed to form an installation space for the seismic isolation device 30. Then, the load of the upper structure 10 supported by the columns 2A and 2B is transferred to the temporary support member 50. In the first embodiment, the part of the columns 2A and 2B between the upper column reinforcement parts 41A and 41B and the lower column reinforcement parts 42A and 42B is cut.

[0050] <S04: Seismic Isolation Device Installation Process> FIG. 6 is an explanatory view 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 foundations 31 are respectively formed on the lower column reinforcement parts 42A and 42B. For example, steel bars and formwork (not shown) are assembled according to the shape of the lower foundation 31, and concrete is placed to form the lower foundation 31. At this time, it is advisable to place the concrete with the base plate for installing the seismic isolation device 30 arranged. Also, it is advisable to connect the steel bars and the like embedded in the lower foundation 31 to the joints 43 embedded when forming the lower column reinforcement parts 42A and 42B. In FIG. 6, the lower foundation on one side in the X direction is the first lower foundation 31A having the first lower protrusion 22, and the lower foundation on the other side in the X direction is the second lower foundation 31B having the second lower protrusion 23.

[0051] Next, the seismic isolation device 30 (the first seismic isolation device 30A) is installed on the first lower foundation 31A, and the seismic isolation device 30 (the second seismic isolation device 30B) is installed on the second lower foundation 31B. For example, the lower part of the seismic isolation device 30 is fixed to the base plate integrated with the lower foundation 31 with bolts or the like. Then, upper foundations 32 are respectively formed between the first seismic isolation device 30A and the upper column reinforcement part 41A, and between the second seismic isolation device 30B and the upper column reinforcement part 41B. Similar to the lower foundation 31, steel bars and formwork (not shown) are assembled according to the shape of the upper foundation 32, and concrete is placed with the base plate arranged to form the upper foundation 32. Then, the upper part of the seismic isolation device 30 is fixed to the base plate integrated with the upper foundation 32 with bolts or the like. In FIG. 6, the upper foundation on one side in the X direction is the first upper foundation 32A having the first upper protrusion 12, and the upper foundation on the other side in the X direction is the second upper foundation 32B having the second upper protrusion 13.

[0052] Thereby, the installation of the seismic isolation device 30 is completed. The seismic isolation device 30 is fixed to the upper part of the column 2 via the upper foundation 32 and is fixed to the lower part of the column 2 via the lower foundation 31, and can follow the movement of the column 2. Also, the seismic isolation device 30 can transmit the load of the superstructure 10 to the substructure 20 while supporting it.

[0053] <S05: Removal process> FIG. 7 is a front view of the existing building 1 after the removal process. After installing the seismic isolation device 30 and confirming that the seismic isolation device 30 functions properly, the temporary support member 50 is contracted and removed. Then, the load of the superstructure 10 is transferred from the temporary support member 50 to the seismic isolation device 30. The horizontal counter member group 60 is also removed.

[0054] <<Regarding the effectiveness of the seismic isolation construction method>> As described above, in the seismic isolation construction method of the first embodiment (FIG. 3A), between the first upper protruding portion 12 and the second upper protruding portion 13, and between the first lower protruding portion 22 and the second lower protruding portion 23, the horizontal counter members 61 and 62 that oppose the horizontal force in the X direction are installed along the X direction. Therefore, during the construction of the seismic isolation construction method, the seismic isolation structure (seismic isolated structure) shown in FIG. 6 is formed, and the construction can be carried out safely.

[0055] Specifically, an upper counter member 61 is installed along the X direction between the first upper protruding portion 12 and the second upper protruding portion 13, and a lower counter member 62 is installed along the X direction between the first lower protruding portion 22 and the second lower protruding portion 23, and the upper counter member 61 and the lower counter member 62 are connected. Therefore, even if an earthquake or strong wind occurs during the construction of cutting columns and walls, the horizontal displacement of the superstructure 10 in the X direction with respect to the substructure 20 can be suppressed by the horizontal counter members 61 and 62, and the construction can be carried out safely.

[0056] Specifically, when a horizontal external force acting toward the other side in the X direction acts on the superstructure 10, the horizontal external force is transmitted to the lower counter member 62 connected to the upper counter member 61 while being resisted by the second upper protruding portion 13 with which the end face on the other side in the X direction of the upper counter member 61 abuts. The transmitted horizontal external force is resisted by the second lower protruding portion 23 with which the end face on the other side in the X direction of the lower counter member 62 abuts. Therefore, the movement of the superstructure 10 to the other side in the X direction is restricted, and the horizontal displacement of the superstructure 10 in the X direction with respect to the substructure 20 can be suppressed.

[0057] Similarly in the reverse direction, when a horizontal external force acting toward one side in the X direction is applied to the upper structure 10, the horizontal external force is transmitted to the lower counter member 62 connected to the upper counter member 61 while being resisted by the first upper protrusion 12 against which the end face on one side in the X direction of the upper counter member 61 abuts. The transmitted horizontal external force is resisted by the first lower protrusion 22 against which the end face on one side in the X direction of the lower counter member 62 abuts. Therefore, the movement of the upper structure 10 toward one side in the X direction is restricted, and the displacement of the upper structure 10 in the X direction relative to the lower structure 20 can be suppressed.

[0058] Further, the upper counter member 61 and the lower counter member 62 of the present embodiment are installed horizontally or substantially horizontally along the X direction and receive forces along their respective major axis directions. Therefore, compared with the case where the counter members are installed obliquely with respect to the X direction, which is different from the present embodiment, the seismic resistance of the building 1 against the horizontal external force is increased, and bending and buckling are less likely to occur in the upper counter member 61 and the lower counter member 62. Therefore, it is not necessary to install an unnecessarily large number of counter members, and the construction becomes easy.

[0059] Also, when counter members are installed obliquely with respect to the X direction, which is different from the present embodiment, many anchors must be driven into columns, beams, floors, etc. of an existing building to attach gusset plates, and counter members must be installed obliquely between the gusset plates, making the construction complicated. In contrast, for the upper counter member 61 of the present embodiment, it is only necessary to bring both end faces in the X direction into contact with the side faces of the first and second upper protrusions 12 and 13, and for the lower counter member 62 as well, it is only necessary to bring both end faces in the X direction into contact with the side faces of the first and second lower protrusions 22 and 23, so the construction becomes easy.

[0060] That is, according to the seismic isolation construction method of the present embodiment, it is possible to facilitate the seismic isolation construction work while increasing the seismic resistance against the horizontal external force acting on the building during construction and to perform the construction safely.

[0061] Note that the horizontal counter members 61 and 62 are not limited to the gusset members 611 and 621. For example, they may be members that are long in the X direction (the first direction) and have surfaces that can contact the side surfaces of the first upper protruding portion 12 or the like at both ends in the X direction (for example, steel materials or precast concrete members). Also, depending on the interval at which the horizontal counter members 61 and 62 are installed as in this embodiment, those obtained by joining the piece members 612 and 622 to the general-purpose gusset members 611 and 621 may be used, or the general-purpose gusset members 611 and 621 may be used alone. By using the general-purpose gusset members 611 and 621, the construction cost can be reduced. Also, the upper counter member 61 that contacts the side surfaces of the first and second upper protruding portions 12 and 13 is not limited to one and may be a plurality of connected members. Similarly, the lower counter member 62 that contacts the side surfaces of the first and second lower protruding portions 22 and 23 is not limited to one and may be a plurality of connected members. At this time, the upper counter members 61 and the lower counter members 62 may be connected via connecting members installed along the X direction (the first direction). Also, in FIG. 4C, only one row of horizontal counter members (61, 62) is arranged, but the horizontal counter members (61, 62) may be arranged in a plurality of rows side by side in the Y direction.

[0062] FIG. 8 is a schematic plan view of the existing building 1. So far, the case of installing the horizontal counter members 61 and 62 along the X direction has been described as an example, but the horizontal counter members 61 and 62 of this embodiment can also be installed along the horizontal direction intersecting the X direction. For example, as shown in FIG. 8, a horizontal counter member group 60 can be installed between two columns 2A and 2C arranged at intervals in the Y direction (the first direction at this time) orthogonal to the X direction. By doing so, during construction in which columns and walls are cut, the displacement of the upper structure 10 in the Y direction with respect to the lower structure 20 can be suppressed. In FIG. 8, the horizontal counter member group 60 that resists the horizontal external force in the X direction is denoted as 60X, and the horizontal counter member group 60 that resists the horizontal external force in the Y direction is denoted as 60Y. As shown in FIG. 8, by installing the horizontal counter member groups 60 along the X direction and the Y direction respectively, the displacement of the upper structure 10 in the X direction and the Y direction can be suppressed.

[0063] Note that the horizontal countermeasure member group 60 is not necessarily installed only in the space between all the columns 2 to be constructed (the columns 2 to be cut) and the adjacent columns 2. In a range where construction can be carried out safely, as shown in FIG. 8, it is not necessary to install the horizontal countermeasure member group 60 around some of the columns 2. Generally, when the load-bearing capacities of the countermeasure members in the X direction (for example, the horizontal countermeasure member group 60X) and the countermeasure members in the Y direction (for example, the horizontal countermeasure member group 60Y) are about the same, it is advisable to install the same number of countermeasure members in the X direction and the Y direction respectively. Also, the displacement of the superstructure 10 due to the horizontal external force can be suppressed by the load-bearing wall (not shown) or the outer wall before cutting, or by fastening the wall after cutting with steel plates, PC steel materials, etc.

[0064] In the first embodiment, two members (the upper countermeasure member 61 and the lower countermeasure member 62) are installed as the horizontal countermeasure members. By doing so, even when the vertical distance between the first upper protrusion 12 and the first lower protrusion 22 is relatively large, the horizontal external force acting on the superstructure 10 can be transmitted to the substructure 20 by the horizontal countermeasure members 61 and 62, and the displacement of the superstructure 10 can be suppressed.

[0065] In the first embodiment, the upper countermeasure member 61 and the lower countermeasure member 62 are connected via a connecting member 63 installed along the X direction. Therefore, even when the vertical distance between the first upper protrusion 12 and the first lower protrusion 22 is even larger, the horizontal external force acting on the superstructure 10 can be transmitted to the substructure 20 by the horizontal countermeasure members 61 and 62 and the connecting member 63, and the displacement of the superstructure 10 can be suppressed.

[0066] Similar to the horizontal countermeasure members 61 and 62, the connecting member 63 is also installed horizontally or substantially horizontally along the X direction, so that the occurrence of bending and buckling of the connecting member 63 can be suppressed, and the horizontal external force acting on the superstructure 10 can be efficiently transmitted. Also, the construction of the connecting member 63 becomes easier.

[0067] Figs. 9A and 9B are explanatory views of a modified example of the horizontal opposing member group 60. Without being limited to the above, when the vertical distance between the first upper protruding portion 12 and the first lower protruding portion 22 is narrow, the configuration of the horizontal opposing member group 60 may be changed. For example, as shown in Fig. 9A, the upper opposing member 61 and the lower opposing member 62 installed along the X direction may be directly connected by bolts or the like (not shown) without passing through the connecting member 63.

[0068] Also, as shown in Fig. 9B, one horizontal opposing member 69 may be installed between the first upper protruding portion 12 and the second upper protruding portion 13 and also between the first lower protruding portion 22 and the second lower protruding portion 23. In this case, one end face of the horizontal opposing member 69 on one side in the X direction abuts against both side faces of the first upper protruding portion 12 (column upper reinforcing portion 41A) and the first lower protruding portion 22 (column lower reinforcing portion 42A), and the other end face of the horizontal opposing member 69 on the other side in the X direction abuts against both side faces of the second upper protruding portion 13 (column upper reinforcing portion 41B) and the second lower protruding portion 23 (column lower reinforcing portion 42B).

[0069] Also, in the first embodiment, in the horizontal opposing member installation step (Fig. 4A), a filler 65 is filled between the side face 13a of the second upper protruding portion 13 and the face 61b of the upper opposing member 61 facing it. In this way, it is desirable to fill the filler 65 between at least one side face of the first upper protruding portion 12 and the second upper protruding portion 13 and the face of the upper opposing member 61 (horizontal opposing member) facing the side face.

[0070] By doing so, even if there are inclinations or unevenness on the side faces of the first and second upper protruding portions 12 and 13, or if the upper opposing member 61 is bent, the end face of the upper opposing member 61 can be made to abut against the side faces of the first and second upper protruding portions 12 and 13 in a gapless manner. Therefore, it is possible to prevent local forces from acting on the side faces of the first and second upper protruding portions 12 and 13 and the end faces of the upper opposing member 61. Thus, the shear strength of the building 1 against horizontal external forces is increased, and it becomes difficult for the upper opposing member 61 to bend or buckle. Also, damage to the first and second upper protruding portions 12 and 13 can be suppressed.

[0071] Similarly, in the first embodiment, a filler 65 is filled between the side surface 23a of the second lower protruding portion 23 and the surface 62b of the lower opposing member 62 facing it. In this way, it is desirable to fill the filler 65 between the side surface of at least one of the first lower protruding portion 22 and the second lower protruding portion 23 and the surface of the lower opposing member 62 (horizontal opposing member) facing the side surface.

[0072] By doing so, the end surface of the lower opposing member 62 can be brought into surface contact with the side surfaces of the first and second lower protruding portions 22 and 23 without any gaps. Therefore, it is possible to prevent local forces from acting on the side surfaces of the first and second lower protruding portions 22 and 23 and the end surfaces of the lower opposing member 62. Thus, the shear strength of the building 1 against horizontal external forces is increased, and it becomes difficult for the lower opposing member 62 to bend or buckle. Also, damage to the first and second lower protruding portions 22 and 23 can be suppressed.

[0073] However, it is not limited to the above, and the horizontal opposing members 61 and 62 may be installed without using the filler 65. Also, construction can be facilitated by providing the filler 65 only on the other side in the X direction of the horizontal opposing members 61 and 62 as in the first embodiment. On the other hand, when the filler 65 is provided on both sides of the horizontal opposing members 61 and 62 in the X direction, both end surfaces of the horizontal opposing members 61 and 62 are surely brought into surface contact with the side surfaces of the first and second upper protruding portions 12 and 13 and the first and second lower protruding portions 22 and 23.

[0074] Also, in the first embodiment, in the horizontal opposing member installation step (FIG. 4A), a support member 64 that supports the horizontal opposing members 61 and 62 from below is installed. By providing the support member 64, deflection due to the self-weight of the horizontal opposing members (upper opposing member 61, lower opposing member 62) and the connecting member 63 can be suppressed. Also, instead of the support member 64, for example, a reinforcing portion formed by placing concrete below the installation position of the lower opposing member 62 can be formed, and the lower opposing member 62 etc. can be supported by the reinforcing portion. However, compared to that, the installation of the support member 64 is easy, and since the support member 64 can be removed after construction, an effective space during construction can be ensured.

[0075] However, it is not limited to the above. For example, as shown in FIG. 9B, the horizontal opposing members 69 may not be supported by the support members. Also, not limited to the support member 64 shown in FIG. 4A, for example, as shown in FIG. 9A, the central portions of the horizontal opposing members 61 and 62 in the X direction may be supported by the support member 64, or may be supported by a ridge-restraining member that is long in the X direction (not shown). Further, the horizontal opposing members 61 and 62 may be supported by suspending them from above.

[0076] Also, in the first embodiment, after the horizontal opposing member installation step, between the first upper protruding portions 12 and the first lower protruding portions 22 on both outer sides where the horizontal opposing members 61 and 62 are installed, and between the second upper protruding portions 13 and the second lower protruding portions 23, a step of installing the seismic isolation devices 30 is respectively carried out. That is, the horizontal opposing members 61 and 62 are installed in the vicinity of the column 2 that is cut to install the seismic isolation device 30. Therefore, the displacement of the upper structure 10 with respect to the lower structure 20 can be more reliably suppressed by the horizontal opposing members 61 and 2, and construction can be carried out safely.

[0077] Also, in the first embodiment, before the horizontal opposing member installation step and the temporary support member installation step, a reinforcement formation step of forming the column upper reinforcement portions 41A and 41B and the column lower reinforcement portions 42A and 42B is carried out. Therefore, in the horizontal opposing member installation step, the horizontal opposing members 61 and 62 can be abutted against the side surfaces of the column upper reinforcement portions 41A and 41B and the side surfaces of the column lower reinforcement portions 42A and 42B. Thus, the horizontal external force acting on the upper structure 10 can be transmitted from the column upper reinforcement portions 41A and 41B to the upper opposing member 61, and further from the upper opposing member 61 to the lower opposing member 62 and the column lower reinforcement portions 42A and 42B (lower structure 20).

[0078] Also, in the temporary support member installation step, the temporary support members 50 can be abutted against the lower surfaces of the column upper reinforcement portions 41A and 41B and the upper surfaces of the column lower reinforcement portions 42A and 42B. Thus, the temporary support members 50 can be installed around the column 2 to be cut, and after the column 2 is cut, the temporary support members 50 can transmit the load of the upper structure 10 to the lower structure 20.

[0079] However, instead of the reinforcing part formed by the seismic isolation work, the horizontal countermeasure members 61 and 62 may be abutted against the side surfaces of the first and second upper protruding parts 12 and 13 and the side surfaces of the first and second lower protruding parts 22 and 23 that the existing building 1 originally has. Similarly, the temporary support member 50 may be abutted against the lower surface of the upper structure 10 and the upper surface of the lower structure 20 that the existing building 1 originally has.

[0080] ===Second Embodiment=== FIG. 10 is a flowchart showing the procedure of the seismic isolation construction method of the second embodiment. FIG. 11A is an explanatory diagram of the cutting process of the columns (2A, 2B), and FIG. 11B is an explanatory diagram of the seismic isolation device installation process. FIG. 12 is an explanatory diagram of the horizontal countermeasure member installation process in the second embodiment. FIG. 13A is an explanatory diagram of the cutting process of another column (2D), and FIG. 13B is an explanatory diagram of the other seismic isolation device installation process. FIGS. 14A to 14D are schematic plan views of the existing building 1. In FIGS. 14A to 14D, the columns 2 with the seismic isolation devices 30 installed at the cut portions are shown as white squares, and the columns 2 that are not cut and do not have the seismic isolation devices 30 installed are shown as black squares.

[0081] In the seismic isolation construction method of the second embodiment, first, a reinforcing part forming step (S11) is performed in the same manner as in the first embodiment (FIG. 2). However, if there is no need to reinforce the existing building 1, the reinforcing part forming step is not necessary. Next, as shown in FIG. 11A, a temporary support member installation step (S12) of installing the temporary support member 50 around the columns 2A and 2B to be constructed is performed, but the horizontal countermeasure member is not installed between the columns 2A and 2B to be constructed. Next, a column cutting step (S13) is performed, and a seismic isolation device installation step (S14) is performed on the columns 2A and 2B as shown in FIG. 11B. Specifically, at the cut portion of the column 2A, the first lower foundation 31A is formed, the first seismic isolation device 30A is installed on the first lower foundation 31A, and then the first upper foundation 32A is formed. Also, at the cut portion of the column 2B, the second lower foundation 31B is formed, the second seismic isolation device 30B is installed on the second lower foundation 31B, and then the second upper foundation 32B is formed. As a result, as shown in FIG. 14A, the seismic isolation devices 30 are installed on the columns 2A and 2B.

[0082] Thereafter, after the seismic isolation device installation process (S14), as shown in FIGS. 12 and 14B, a horizontal countermeasure member installation process (S15) is performed on the space between the columns 2A and 2B where the installation of the seismic isolation device 30 is completed. Specifically, the horizontal countermeasure member group 70 of the second embodiment includes one horizontal countermeasure member 71 (e.g., a bracing member) and two support members 72 (e.g., piece materials). And it is between the first upper foundation 32A (the first upper protruding portion) installed on the first seismic isolation device 30A and the second upper foundation 32B (the second upper protruding portion) installed on the second seismic isolation device 30B, and between the first lower foundation 31A (the first lower protruding portion) installed under the first seismic isolation device 30A and the second lower foundation 31B installed under the second seismic isolation device 30B, the horizontal countermeasure member 71 is installed along the X direction. That is, one end face of the horizontal countermeasure member 71 on one side in the X direction is brought into contact with the side faces of the first upper foundation 32A and the first lower foundation 31A, and the other end face of the horizontal countermeasure member 71 on the other side in the X direction is brought into contact with the side faces of the second upper foundation 32B and the second lower foundation 31B, and the horizontal countermeasure member 71 is installed horizontally or substantially horizontally along the X direction.

[0083] Also in this case, the horizontal external force acting on the superstructure 10 can be transmitted from the upper foundation 32 to the horizontal countermeasure member 71, and further from the horizontal countermeasure member 71 to the lower foundation 31 (the substructure 20). Therefore, the displacement of the superstructure 10 in the X direction with respect to the substructure 20 can be suppressed. In addition, since the horizontal countermeasure member 71 is installed horizontally or substantially horizontally, the strength of the building 1 against the horizontal external force is increased, and it is difficult for bending or buckling to occur in the horizontal countermeasure member 71.

[0084] In addition, in the seismic isolation construction method of this embodiment, a seismic isolation device 30 is installed in the middle of a plurality of columns 2 in the construction stage. That is, the upper structure 10 and the lower structure 20 are located at positions different from the locations where the first seismic isolation device 30A and the second seismic isolation device 30B are installed, and have a third upper protruding portion (for example, the third upper protruding portion 14 in FIG. 11A) protruding downward from the upper horizontal portion 11 and a third lower protruding portion (for example, the third lower protruding portion 24 in FIG. 11A) protruding upward from the lower horizontal portion 21. A step of installing the seismic isolation device 30 (another seismic isolation device installation step S16) between the third upper protruding portion 14 and the third lower protruding portion 24, that is, in the middle of a column 2 (for example, the column 2D in FIG. 11A) different from the columns 2A and 2B, may be performed after the horizontal countermeasure member installation step. That is, after the horizontal countermeasure member installation step (FIG. 12), a temporary support member 50 is installed around the column 2D, and a column cutting step (protruding portion forming step) is carried out. Specifically, a part of the column 2D extending from the lower horizontal portion 21 to the upper horizontal portion 11 is cut (FIG. 13A), and a third upper protruding portion 14 that is the upper part of the column 2D and a third lower protruding portion 24 that is the lower part of the column 2D are formed. Then, a third seismic isolation device 30D is installed between the third upper protruding portion 14 and the third lower protruding portion 24 (FIGS. 13B and 14C). Even during this construction, the horizontal countermeasure member 71 installed between the columns 2A and 2B enables safe construction.

[0085] Thus, in the initial stage of the seismic isolation construction work, when many columns 2 and walls (shear walls (not shown) and outer walls) have not been cut (for example, FIG. 14A), even if no horizontal countermeasure member is installed in the space between the columns 2A and 2B to be constructed, the displacement of the upper structure 10 can be suppressed. As the work progresses and the cutting of the columns 2 and walls proceeds (for example, FIG. 14B), a horizontal countermeasure member group 70 may be installed between the columns 2A and 2B where the seismic isolation device 30 has already been installed. By doing so, construction can be carried out safely. Then, as shown in FIG. 14D, while installing the horizontal countermeasure member group 70 at the locations where the seismic isolation device 30 is installed, it is preferable to finally install the seismic isolation device 30 in the middle of all the columns 2. Note that it is not limited to installing the horizontal countermeasure member group 70 around all the columns 2 where the seismic isolation device 30 is installed. In the range where construction can be carried out safely, as shown in FIG. 14D, it is not necessary to install the horizontal countermeasure member group 70 around some of the columns 2.

[0086] Also, the horizontal opposing member 71 of the second embodiment can also be installed in a direction intersecting the X direction (orthogonal Y direction). In this case, displacement of the upper structure 10 in the Y direction can be suppressed. In FIG. 14D, the horizontal opposing member group 70 against the horizontal external force in the X direction is labeled as 70X, and the horizontal opposing member group 70 against the horizontal external force in the Y direction is labeled as 70Y.

[0087] Also, in the second embodiment, the horizontal opposing member 71 is brought into contact with the side surfaces of the upper foundation 32 and the lower foundation 31 of the seismic isolation device 30. Compared with the vertical intervals between the upper column reinforcement parts 41A and 41B and the lower column reinforcement parts 42A and 42B, the vertical interval between the upper foundation 32 and the lower foundation 31 is narrow. Therefore, in the second embodiment, the number of the horizontal opposing members 71 can be reduced (here, made one), or the connecting members can be made unnecessary. Thus, the process of installing the horizontal opposing members can be carried out more easily.

[0088] Also, it is desirable that the horizontal opposing member 71 of the second embodiment is also supported by the support member 72 from below. By doing so, deflection due to the self-weight of the horizontal opposing member 71 can be suppressed. In that case, as shown in FIG. 12, it is desirable to install the support member 72 on the upper surface of the lower foundation 31. By doing so, the number of the support members 72 can be reduced compared with the case of installing the support members from the floor surface FL2 at the construction stage. Also, by adjusting the installation height of the horizontal opposing member 71 by the support member 72, the horizontal opposing member 71 can be brought into contact with the lower foundation 31 and the upper foundation 32 evenly.

[0089] Also, it is desirable to fill the filler 73 between the side surface of the upper foundation 32 (at least one of the first upper protruding part and the second upper protruding part) and the horizontal opposing member 71 facing it for the horizontal opposing member 71 of the second embodiment. Similarly, it is desirable to fill the filler 73 between the side surface of the lower foundation 31 (at least one of the first lower protruding part and the second lower protruding part) and the horizontal opposing member 71 facing it. By doing so, the horizontal opposing member 71 can be brought into surface contact with the upper foundation 32 and the lower foundation 31, and the occurrence of locations where force is locally applied can be prevented.

[0090] The above embodiments are for facilitating the understanding of the present invention and are not for limiting the interpretation of the present invention. It goes without saying that the present invention can be changed and improved without departing from its gist, and equivalents thereof are included in the present invention.

[0091] For example, a seismic isolation construction method that performs both the installation of the horizontal opposing members 61 and 62 in the first embodiment and the installation of the horizontal opposing member 71 in the second embodiment may be used. By combining both, the degree of freedom in the construction plan is increased.

Explanation of Reference Numerals

[0092] 1 Existing building, 2 Column, 3 Beam, 10 Superstructure, 11 Upper horizontal part, 12 First upper protruding part, 13 Second upper protruding part, 14 Third upper protruding part, 20 Substructure, 21 Lower horizontal part, 22 First lower protruding part, 23 Second lower protruding part, 24 Third lower protruding part, 30 Seismic isolation device, 30A First seismic isolation device, 30B Second seismic isolation device, 30D Third seismic isolation device, 31 Lower foundation, 31A First lower foundation, 31B Second lower foundation, 32 Upper foundation, 32A First upper foundation, 32B Second upper foundation 40 Reinforcement part, 41 Column upper reinforcement part, 42 Column lower reinforcement part, 43 Joint, 44 PC steel bar, 50 Temporary support member, 60 Horizontal opposing member group, 61 Upper opposing member (horizontal opposing member), 62 Lower opposing member (horizontal opposing member), 63 Connecting member, 64 Support member, 65 Filling material, 66 Bolt, 67 Nut, 68 Washer plate, 69 Horizontal opposing member, 70 Horizontal opposing member group, 71 Horizontal opposing member, 72 Support member, 73 Filling material,

Claims

1. A seismic isolation construction method in which a seismic isolation device is provided between an upper structure and a lower structure, wherein the upper structure has an upper horizontal portion, a first upper protruding portion protruding downward from the upper horizontal portion and arranged at intervals in a first direction, and a second upper protruding portion, the lower structure has a lower horizontal portion, a first lower protruding portion protruding upward from the lower horizontal portion and arranged at intervals in the first direction, and a second lower protruding portion, a horizontal countermeasure member installation step of installing a horizontal countermeasure member that resists horizontal forces in the first direction along the first direction is provided between the first upper protruding portion and the second upper protruding portion and between the first lower protruding portion and the second lower protruding portion, a seismic isolation device installation step of installing a first seismic isolation device between the first upper protruding portion and the first lower protruding portion and installing a second seismic isolation device between the second upper protruding portion and the second lower protruding portion, the horizontal countermeasure member installation step is carried out after the seismic isolation device installation step, after the horizontal countermeasure member installation step, a part of a column extending from the lower horizontal portion to the upper horizontal portion is cut to form a third upper protruding portion that is the upper part of the column and protrudes downward from the upper horizontal portion, and a third lower protruding portion that is the lower part of the column and protrudes upward from the lower horizontal portion, which is a protruding portion forming step, a seismic isolation construction method characterized by having another seismic isolation device installation step of installing a third seismic isolation device between the third upper protruding portion and the third lower protruding portion after the protruding portion forming step.

2. The seismic isolation construction method according to Claim 1, wherein the first upper protruding portion has a first upper base installed on the first seismic isolation device, the first lower protruding portion has a first lower base installed under the first seismic isolation device, the second upper protruding portion has a second upper base installed on the second seismic isolation device, the second lower protruding portion has a second lower base installed under the second seismic isolation device, in the seismic isolation device installation step, after forming the first lower base and installing the first seismic isolation device on the first lower base, the first upper base is formed, and after forming the second lower base and installing the second seismic isolation device on the second lower base, the second upper base is formed. A seismic isolation construction method characterized by bringing the horizontal resistance member into contact with the side surfaces of the first upper foundation, the side surfaces of the first lower foundation, the side surfaces of the second upper foundation, and the side surfaces of the second lower foundation in the horizontal resistance member installation step.

Images