Base-isolated building structure and construction method for base-isolated building structure

Abstract

To provide a base-isolated building structure that can be provided with a fire compartment wall between a lower structure and an upper structure with a simple structure, and a base-isolated building structure construction method.SOLUTION: A base-isolated building structure 1 has: a plurality of column structures 3 supported by a lower structure 2; a plurality of seismic isolation devices 4 installed at upper ends of the respective column structures 3; an upper structure 5 supported by the plurality of seismic isolation devices 4; a beam 6 extended between adjacent column structures 3; a slab 7 supported by the beam 6; and a fire compartment wall 8 provided between the lower structure 2 and slab 7, and partitions the space formed between the lower structure 3 and slab 7.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a seismically isolated building structure and a method for constructing a seismically isolated building structure. [Background technology]

[0002] A known structure for buildings such as hospitals, office buildings, hotels, and apartment buildings is a column-capped seismic isolation building structure in which, for example, the basement floor or the like is used as a seismic isolation floor, and a seismic isolation device is installed at the upper end of a column structure supported by a lower structure that constitutes the floor of the seismic isolation floor, and this seismic isolation device supports an upper structure that constitutes the ceiling of the seismic isolation floor (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-16941 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the seismic isolation building structure described above, it is preferable that a fire compartment wall with a simple structure can be provided between the lower structure and the upper structure.

[0005] However, in the above-mentioned seismically isolated building structure, when a horizontal load is applied to the lower structure due to an earthquake or the like, the seismic isolation device causes the lower structure to be displaced horizontally relative to the upper structure, so the fire compartment wall installed between the lower structure and the upper structure needs to be designed with a fit or mechanism that can absorb the displacement, which causes the problem that the structure of the fire compartment wall installed on the seismically isolated floor becomes complicated.

[0006] Therefore, an object of the present invention is to provide a seismically isolated building structure and a construction method for a seismically isolated building structure that makes it possible to install a fire compartment wall between a lower structural member and an upper structural member with a simple structure. [Means for solving the problem]

[0007] One aspect of the present invention is as follows.

[0008] [1] A plurality of column structures supported by a lower structure; A plurality of seismic isolation devices installed at the upper ends of the respective column structures; An upper structure supported by a plurality of the seismic isolation devices; A beam spanning between adjacent column structures; A slab supported by the beam; A seismically isolated building structure having a fire compartment wall provided between the lower structure and the slab, partitioning the space formed between the lower structure and the slab.

[0009] [2] The seismic isolation building structure described in [1] has a seismic wall provided between adjacent column structures.

[0010] [3] A seismically isolated building structure as described in [1] or [2], having equipment placement space between the slab and the upper structure.

[0011] [4] A method for constructing a seismic isolated building structure according to any one of [1] to [3], A seismic isolation building structure construction method comprising a seismic isolation structure forming step of removing a portion of the column connecting the lower structure and the upper structure, and installing the seismic isolation device between the column structure having the remaining portion of the column and the upper structure.

[0012] [5] The seismic isolation building structure construction method described in [4], wherein the slab formation step of forming the slab is performed after the seismic isolation structure formation step. Effect of the Invention

[0013] According to the present invention, it is possible to provide a seismically isolated building structure and a construction method for a seismically isolated building structure that make it possible to install a fire compartment wall between a lower structural member and an upper structural member with a simple structure. [Brief description of the drawings]

[0014] [Figure 1] 1 is an explanatory diagram showing an outline of a seismically isolated building structure according to one embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional view showing the arrangement of fire compartment walls, equipment, piping, etc. in the seismic isolation building structure shown in FIG. [Diagram 3] FIG. 1 is a cross-sectional view showing the arrangement of fire compartment walls, equipment, piping, etc. in a seismic isolation building structure as a comparative example. [Figure 4A] FIG. 2 is an explanatory diagram illustrating step a as an example of a procedure for constructing the seismic isolated building structure shown in FIG. [Figure 4B] FIG. 11 is an explanatory diagram for explaining a procedure b following a procedure a. [Figure 4C] FIG. 11 is an explanatory diagram for explaining a procedure c following the procedure b. [Figure 4D] FIG. 11 is an explanatory diagram for explaining step d which follows step c. [Figure 4E] FIG. 11 is an explanatory diagram for explaining step e following step d. [Figure 4F] FIG. 11 is an explanatory diagram for explaining step f following step e. [Figure 4G] FIG. 11 is an explanatory diagram for explaining step g following step f. [Figure 4H] FIG. 11 is an explanatory diagram for explaining step h following step g. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a base-isolated building structure 1 according to an embodiment of the present invention will be described with reference to the drawings.

[0016] A building 100 shown in Fig. 1 has a basement floor 101 to which a basement isolation building structure 1 according to an embodiment of the present invention is applied, and the basement floor 101 is the basement isolation floor. This building 100 was constructed as a non-basement isolation structure without a basement isolation structure, and then renovated to have the basement isolation building structure 1 by a basement isolation renovation method also called retrofit in order to increase resistance to earthquakes.

[0017] In this embodiment, the building 100 is a hospital (ward), but is not limited thereto and may be a building used for other purposes, such as an office building, a hotel, or an apartment building. The base-isolated building structure 1 is not limited to being applied to the basement floor 101 of the building 100, but may be applied to other floors of the building 100. Furthermore, in this embodiment, the building 100 is made of reinforced concrete, but is not limited thereto.

[0018] As shown in FIG. 1, the seismic isolated building structure 1 has a lower structural body 2, a plurality of column structural bodies 3, a plurality of seismic isolation devices 4, an upper structural body 5, a beam 6, a slab 7 and a fire compartment wall 8.

[0019] The lower structure 2 is a part made of reinforced concrete and includes, for example, a floor 2a of the basement floor 101, foundation beams 2b, and footings 2c supporting the foundation piles, and is fixed to the ground 102.

[0020] The plurality of column structures 3 are supported by the lower structure 2 and arranged at intervals on the basement floor 101. In this embodiment, the plurality of column structures 3 are each made of reinforced concrete, and have a column main body 3a whose lower end is supported by a corresponding footing 2c and extends straight in the vertical direction, and a lower base 3b integrally provided at the upper end of the column main body 3a. The upper end of each column structure 3 does not reach the upper structure 5, and the lower base 3b faces the upper structure 5 at an interval. Note that the column structure 3 may be configured not to be provided with the lower base 3b.

[0021] The plurality of seismic isolation devices 4 are installed on the upper ends, i.e., the upper surfaces of the lower base portions 3b, of the corresponding column structures 3. When the plurality of column structures 3 are configured not to have the lower base portions 3b, the seismic isolation devices 4 may be installed on the upper ends of the column main bodies 3a of the plurality of column structures 3, respectively.

[0022] Although not shown in detail, the seismic isolation device 4 may have a configuration in which a laminated seismic isolation rubber is arranged between a pair of flanges spaced apart vertically. In this case, the lower flange of the seismic isolation device 4 is fixed to the upper end (upper surface of the lower base portion 3b) of the column structure 3. Note that the seismic isolation device 4 is not limited to the above configuration, and may have another configuration, such as a sliding bearing.

[0023] The upper structure 5 is a portion made of reinforced concrete, including, for example, a ceiling 5a of the basement floor 101, a plurality of upper bases 5b provided integrally with the ceiling 5a, and a portion 5c of the building 100 above the basement floor 101. The plurality of upper bases 5b face the lower bases 3b of the corresponding column structures 3 from above, and the upper structure 5 is supported at these upper bases 5b by a plurality of seismic isolation devices 4 installed on the lower bases 3b of the plurality of column structures 3. The upper structure 5 may be configured not to include the upper bases 5b. In this case, the upper structure 5 may be configured to be supported by a plurality of seismic isolation devices 4 at other portions.

[0024] The upper structure 5 is supported by multiple seismic isolation devices 4 installed on the upper ends of multiple column structures 3 supported by the lower structure 2, so that in the event of an earthquake, horizontal displacement of the lower structure 2 is absorbed by the seismic isolation devices 4, making it difficult for the displacement to be transmitted. In other words, the seismic isolated building structure 1 to the building 100 is separated in the portion where the multiple seismic isolation devices 4 are provided into a non-seismic isolation side region R1 including the lower structure 2 and column structures 3 supporting the multiple seismic isolation devices 4, and a seismic isolation side region R2 including the upper structure 5 supported by the multiple seismic isolation devices 4.

[0025] The beam 6 is bridged between adjacent column structures 3. In this embodiment, the beam 6 is made of reinforced concrete, and both ends of the beam 6 are connected to the lower base parts 3b of the corresponding column structures 3 and supported by the column structures 3. Since the beam 6 is supported by the column structures 3, it belongs to the non-seismically isolated region R1.

[0026] The slab 7 is supported by the beams 6 and disposed between the lower structural body 2 and the upper structural body 5. The slab 7 is formed of a plate material made of a fire-resistant material capable of forming a fire compartment, such as concrete or ALC (Autoclaved Lightweight Aerated Concrete), and divides the basement floor 101 between the lower structural body 2 and the upper structural body 5 into upper and lower sections. Since the slab 7 is supported by the beams 6, it belongs to the non-seismically isolated region R1.

[0027] The fire compartment wall 8 is provided between the lower structure 2 and the slab 7, and divides the space S1 formed between the lower structure 2 and the slab 7 into left and right in FIG. 1. More specifically, the fire compartment wall 8 is formed in a wall shape from a fire-resistant material capable of forming a fire compartment, such as concrete, and the entire lower end is connected to the floor 2a and the entire upper end is connected to the slab 7, so that the spread of fire and the inflow of smoke from one side of the divided space S1 to the other side can be prevented. That is, the fire compartment wall 8 can divide at least one of the spaces S1 between the lower structure 2 and the slab 7 as a fire compartment together with the slab 7. The fire compartment wall 8 is provided between the lower structure 2 and the slab 7, and therefore belongs to the non-seismic side region R1.

[0028] In the seismically isolated building structure 1 of this embodiment, the fire compartment wall 8 is arranged between adjacent column structures 3 and away from the column structures 3, but this is not limited to this, and the fire compartment wall 8 may also be arranged between adjacent column structures 3 such that both side portions of the fire compartment wall 8 are each connected to the corresponding column structures 3.

[0029] As described above, according to the base-isolated building structure 1 of this embodiment, the lower structural body 2, slab 7, and fire compartment wall 8 are each contained within the non-base-isolated region R1 of the building 100, and therefore there is no need to provide the fire compartment wall 8 with a fit or mechanism for absorbing displacement that occurs between the non-base-isolated region R1 and the base-isolated region R2 during an earthquake or the like. Therefore, according to the base-isolated building structure 1 of this embodiment, when providing a fire compartment on the base-isolated floor (basement floor 101) of the building 100, the fire compartment wall 8 can be provided with a simple structure between the lower structural body 2 and the upper structural body 5.

[0030] The seismically isolated building structure 1 of this embodiment can also be configured to have a seismic wall 9 provided between adjacent column structures 3. Both sides of the seismic wall 9 are connected to the corresponding column structures 3, the lower end is connected to the floor 2a, and the upper end is connected to the slab 7. The seismic wall 9 may be provided between at least one pair of column structures 3 among the multiple column structures 3. In this embodiment, the seismic wall 9 is provided between a pair of column structures 3 other than the pair of column structures 3 in which the fire compartment wall 8 is provided.

[0031] In the seismic isolated building structure 1 of this embodiment, the multiple column structures 3 have a cantilever configuration in which only their lower ends are supported by the lower structure 2, so the multiple column structures 3 and the foundation beams 2b supporting them need to be made stronger. In particular, when an existing building 100 that was constructed as a non-seismically isolated structure without a seismic isolation structure is renovated to a structure having the seismic isolated building structure 1, the column structures 3 and the foundation beams 2b need to be reinforced in association with the renovation, and there was a problem that the reinforcement work was complicated.

[0032] To address such problems, the base-isolated building structure 1 of this embodiment is configured to have earthquake-resistant walls 9 provided between adjacent column structures 3, and therefore, by integrating adjacent column structures 3 through the earthquake-resistant walls 9, it is possible to reinforce these column structures 3 and increase their strength. In addition, column structures 3 that are not adjacent to the earthquake-resistant walls 9 are also connected through beams 6 to the column structures 3 reinforced by the earthquake-resistant walls 9, so that the strength of these column structures 3 can also be increased. Therefore, it is not necessary to make the column structure 3 and the foundation beams 2b stronger or to reinforce the column structure 3 and the foundation beams 2b, thereby reducing the construction burden when constructing the seismically isolated building structure 1.

[0033] As shown in Fig. 2, a suspended ceiling 10 may be provided inside a space S1 partitioned by a fire compartment wall 8, and various equipment 11, such as an air conditioner, may be installed between the slab 7 and the suspended ceiling 10, with piping 12 for the equipment 11 and a grape trellis 13 for wiring the equipment 11 arranged therein. In this case, the fire compartment wall 8 may be provided with a compartment penetration structure 14 through which the piping 12 or grape trellis 13 is inserted. The compartment penetration structure 14 may be configured as a fire damper, or a fire compartment penetration treatment may be performed, such as filling gaps with non-combustible material, so as to ensure a fireproof function.

[0034] As shown in the comparative example in FIG. 3, in the case of a structure having a column structure 3 supported by a lower structure 2, a seismic isolation device 4 supported by the column structure 3, and an upper structure 5 supported by the seismic isolation device 4, and a fire compartment wall 16 formed between the lower structure 2 and the upper structure 5 without providing a beam 6 and a slab 7 supported by the beam 6, the fire compartment wall 16 is provided across the non-seismic isolation side region R1 and the seismic isolation side region R2. Therefore, since it is necessary to provide a movable structure 15 capable of absorbing horizontal displacement caused by an earthquake between the seismic isolation side region R1 and the seismic isolation side region R2 in the portion that spans the non-seismic isolation side region R1 and the seismic isolation side region R2, the structure of the fire compartment wall 16 becomes complicated. In contrast, in the seismic isolation building structure 1 of this embodiment, as described above, the slab 7 and the fire compartment wall 8 constituting the fire compartment are both contained in the non-seismic isolation side region R1, so there is no need to provide the movable structure 15, and the configuration can be simplified. In addition, in the comparative example shown in Figure 3, it is necessary to provide a compartment penetration structure 14 such as a fire damper for equipment such as piping 12 that penetrates the fire compartment wall 16 in the seismic isolation side area R2, but in the seismic isolation building structure 1 of this embodiment, there is no need to provide a compartment penetration structure 14 in the seismic isolation side area R2, so that the seismic isolation building structure 1 can be further simplified.

[0035] As shown in Fig. 2, the seismically isolated building structure 1 may be configured to have an equipment arrangement space S2 between the slab 7 and the ceiling 5a of the upper structure 5. With the above configuration, the space between the slab 7 and the ceiling 5a of the upper structure 5 can be effectively utilized. The equipment arrangement space S2 may be used to place equipment 11 on the non-seismically isolated side on the top surface of the slab 7, or may be used to hang equipment 11 on the seismically isolated side on the upper structure 5, or may be used for both.

[0036] Next, with reference to Figures 4A to 4H, we will explain the procedure for renovating an existing building that is a non-seismically isolated structure that does not have the seismically isolated building structure 1 into a structure that has the seismically isolated building structure 1 using the seismically isolated building structure construction method of this embodiment.

[0037] In this embodiment, the seismic isolated building structure construction method for constructing the seismic isolated building structure 1 may include a seismic isolated structure formation step of removing a part of the column 17 connecting the lower structural body 2 and the upper structural body 5 (see FIG. 4C) and installing the seismic isolation device 4 between the column structural body 3 having the remaining part of the column 17 and the upper structural body 5 (see FIG. 4E). According to the above configuration, the seismic isolated building structure 1 can be provided in an existing building. Note that in FIGS. 4A to 4H, the newly formed part is indicated by diagonal hatching, and the removed part is indicated by solid black.

[0038] As shown in Fig. 4H, in the seismic isolated building structure construction method, the slab forming step of forming the slab 7 may be performed after the seismic isolated structure forming step. According to the above configuration, jacking up for installing the seismic isolation device 4 can be performed near the columns 17, so that the seismic isolated building structure 1 can be constructed efficiently.

[0039] More specifically, as shown in Figures 4A to 4F, the seismic isolation structure formation step includes an upper structure reinforcing step (step a: see Figure 4A) of providing an upper base 5b to reinforce the upper end portion of the column 17 of the upper structure 5, a jacking up step (step b: see Figure 4B) of jacking up the upper structure 5 at the upper base 5b using multiple jacks 18, and a column cutting step (step c: see Figure 4C) of cutting the column 17 while the upper structure 5 is jacked up, and in the column cutting step, a portion of the column 17 is cut and removed. Next, the method may include a lower base forming step (step d: see FIG. 4D) of forming a lower base 3b on the upper surface of the column main body 3a, which is the remaining part of the column 17, with the upper structure 5 jacked up, a seismic isolation device installation step (step e: see FIG. 4E) of installing a seismic isolation device 4 on the upper surface of the lower base 3b with the upper structure 5 jacked up, and a jack removal step (step f: see FIG. 4F) of removing the jack 18 used to jack up the upper structure 5 and supporting the upper structure 5 on the seismic isolation device 4. According to the above configuration, the seismic isolation structure forming step can be performed efficiently.

[0040] As shown in Figures 4G to 4H, the base-isolated building structure construction method may include a beam forming step (step g: see Figure 4G) of forming beams 6 that span the upper parts (lower base parts 3b) of adjacent column structures 3, and a slab forming step (step h: see Figure 4H) may be performed after the beam forming step. According to the above configuration, the beams 6 that support the upper parts of the column structures 3 and the slab 7, and the slab 7 can be efficiently formed.

[0041] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention.

[0042] For example, the seismic isolated building structure 1 of this embodiment may be installed in a new building. [Explanation of symbols]

[0043] 1. Seismic isolation building structure 2 Lower structure 2a floor 2b Foundation beam 2c Footing 3 pillar structure 3a Pillar body 3b Lower base 4. Seismic isolation device 5 Upper structure 5a Ceiling 5b Upper base 5c Upper floor 6 beams 7. Slab 8 Fire partition wall 9 Earthquake-resistant walls 10 Suspended Ceiling 11 Equipment 12 Piping 13 Grapevine trellis 14 Compartment penetration structure 15 Movable structure 16 Fire Compartment Wall 17 Pillars 18 Jack 100 Buildings 101 Basement 102 Ground R1 Non-isolated area R2 Seismic isolation side area S1 space S2 Equipment placement space

Claims

1. A plurality of column structures supported by a lower structure; A plurality of seismic isolation devices installed at the upper ends of the respective column structures; An upper structure supported by a plurality of the seismic isolation devices; A beam spanning between adjacent column structures; A slab supported by the beam; A seismically isolated building structure having a fire compartment wall provided between the lower structure and the slab, partitioning the space formed between the lower structure and the slab.

2. The seismic isolation building structure according to claim 1 , further comprising a seismic wall provided between adjacent column structures.

3. The seismically isolated building structure according to claim 1 or 2, further comprising an equipment arrangement space between the slab and the upper structure.

4. A method for constructing the seismic isolated building structure according to claim 1, comprising the steps of: A seismic isolation building structure construction method comprising a seismic isolation structure forming step of removing a portion of the column connecting the lower structure and the upper structure, and installing the seismic isolation device between the column structure having the remaining portion of the column and the upper structure.

5. The seismic isolation building structure construction method according to claim 4 , wherein a slab forming step of forming the slab is performed after the seismic isolation structure forming step.

Images