Seismic isolation structure

Abstract

The present invention provides a seismic isolation structure 1 that can secure a working space in the space 22 below the elevator shaft 40 by not providing a seismic isolation support at the lower end of the elevator shaft 40. [Solution] The seismic isolation structure 1 comprises a lower structure 20, an upper structure 10 supported on the lower structure 20 via a seismic isolation device 30, and a reinforced concrete elevator shaft 40 whose upper end is fixed to the upper structure 10 and which extends downward through the lower structure 20. The elevator shaft 40 includes a wall portion 44 for forming an internal space 43 through which an elevator car 42 moves up and down, a bottom portion 46 that closes the internal space 43 at the lower end of the wall portion 44, and a plurality of first tension members 51 and second tension members 52 that extend from the upper structure 10 towards the bottom portion 46 within the wall portion 44. The wall portion 44 is a prestressed concrete structure in which tensile force is applied to the plurality of first tension members 51 and second tension members 52.

Description

Technical Field

[0001] The present invention relates to a seismic isolation structure provided with an elevator hoistway.

Background Art

[0002] A seismic isolation structure provided with a lower hoistway for an elevator extending downward from a seismic isolation device has been proposed (Patent Document 1).

[0003] The lower hoistway of Patent Document 1 has a lightweight framework structure composed of vertical beams and horizontal beams because it is suspended from the seismic isolation building, and a shock absorber that can move horizontally is provided below the lower hoistway.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Even in the seismic isolation structure of Patent Document 1, when the underground floor becomes deeper and the lower hoistway becomes longer, the load due to its own weight increases, and it is expected to provide a seismic isolation support at the lower end of the lower hoistway to support the lower hoistway. However, if a shock absorber that can move horizontally as in Patent Document 1 or a seismic isolation support is installed below the lower hoistway, the space below the lower hoistway will be restricted.

[0006] Therefore, an object of the present invention is to provide a seismic isolation structure that can secure the space below the hoistway by not providing a seismic isolation support at the lower end of the hoistway.

Means for Solving the Problems

[0007] The present invention has been made to solve at least a part of the above problems and can be realized as the following aspects or application examples.

[0008] [1] One embodiment of the seismic isolation structure according to the present invention is: Substructure and An upper structure supported on the lower structure via a seismic isolation device, A reinforced concrete elevator shaft, the upper end of which is fixed to the upper structure and which extends downward through the lower structure, Equipped with, The elevator shaft includes a wall portion for forming an internal space through which the elevator car moves up and down, a bottom portion that closes the internal space at the lower end of the wall portion, and a plurality of tensioning members extending from the upper structure toward the bottom portion within the wall portion. The wall section is characterized by being a prestressed concrete structure in which tensile force is applied to the plurality of tensioning members.

[0009] [2] In one embodiment of the above-mentioned seismic isolation structure, The upper ends of each of the aforementioned tensioning members can be fixed to the upper structure.

[0010] [3] In one embodiment of the above-mentioned seismic isolation structure, The plurality of tensioning members include a plurality of first tensioning members and a plurality of second tensioning members that are shorter than the first tensioning members. The plurality of first tension members extend from the superstructure to the bottom, The plurality of second tensioning members can extend from the superstructure to a position higher than half the total height of the wall.

[0011] [4] In one embodiment of the above-mentioned seismic isolation structure, The aforementioned elevator shaft has an opening for entering and exiting the elevator. The wall portion can be configured such that the first tensioning member is positioned at the portion of the plurality of tensioning members closest to the opening.

[0012] [5] In one embodiment of the above-mentioned seismic isolation structure, The plurality of tension members can be arranged inside the vertical and horizontal reinforcing bars constituting the reinforced concrete structure of the wall portion.

Advantages of the Invention

[0013] According to one aspect of the seismic isolation structure according to the present invention, since there is no need to provide a seismic isolation bearing under the elevator shaft by using an elevator shaft having a prestressed concrete structure, a space under the elevator shaft can be secured.

Brief Description of the Drawings

[0014] [Figure 1] It is a longitudinal sectional view of the seismic isolation structure according to the present embodiment. [Figure 2] It is a longitudinal sectional view of the elevator shaft. [Figure 3] It is a plan view of the elevator shaft. [Figure 4] It is a partially enlarged longitudinal sectional view of the elevator shaft. [Figure 5] It is a plan view of the elevator shaft according to a modified example.

Modes for Carrying Out the Invention

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0016] 1. Outline of the Seismic Isolation Structure The seismic isolation structure 1 according to the present embodiment will be described with reference to FIG. 1. FIG. 1 is a longitudinal sectional view of the seismic isolation structure 1 according to the present embodiment.

[0017] As shown in FIG. 1, the seismic isolation structure 1 includes a lower structure 20, an upper structure 10 supported on the lower structure 20 via a seismic isolation device 30, and a reinforced concrete elevator shaft 40 having an upper end fixed to the upper structure 10 and extending downward through the lower structure 20. The seismic isolation structure 1 includes an elevator.

[0018] The superstructure 10 is a multi-story building that extends upward, supported by multiple seismic isolation devices 30 located below ground level (GL). The first floor is formed on the upper surface of the upper slab 13. The superstructure 10 includes, for example, an upper hoistway in the center through which an elevator car 42 moves up and down, but this is omitted in Figure 1. The hoistway 40, which is fixed to the superstructure 10 and extends downward, will be described later. The hoistway 40 and the upper hoistway, which is omitted from the illustration, are formed to be continuous vertically (in the Z direction), but an elevator without an upper hoistway is also possible.

[0019] The substructure 20 is an underground building with multiple floors extending downwards and located below the seismic isolation device 30, but may also include an above-ground building if the seismic isolation device 30 is located above the ground level (GL). The substructure 20 may include, for example, an elevator car 42 that moves up and down in the center. A cylindrical space is formed in which the elevator shaft 40 is located, and a space 22 below the elevator shaft is formed at the lower end of this cylindrical space. There are no seismic isolation bearings supporting the elevator shaft 40 in space 22. Therefore, sufficient working space can be secured in space 22.

[0020] The seismic isolation device 30 is installed in the seismic isolation layer 32 located between the lower structure 20 and the upper structure 10. Multiple seismic isolation devices 30 are installed on the lower structure 20 at intervals and support the upper structure 10 which is placed on top of the seismic isolation devices 30. The seismic isolation device 30 is a mechanism that reduces horizontal shaking such as earthquakes transmitted to the upper structure 10 and provides a force to restore the relative position of the upper structure 10 to its original state, and is a so-called isolator. The seismic isolation device 30 includes at least one of laminated rubber, sliding bearings, and rolling bearings. The seismic isolation device 30 may further include damping devices, for example, oil dampers, lead dampers, steel dampers, friction dampers, etc.

[0021] 2. Elevator The elevator shaft 40 will be explained using Figures 1 to 4. Figure 2 is a longitudinal section of the elevator shaft 40, Figure 3 is a plan view of the elevator shaft 40, and Figure 4 is a partially enlarged longitudinal section of the elevator shaft 40. Figure 2 is a cross-sectional view of AA in Figure 3. Figure 4 shows an enlarged view of the circled area in Figure 3.

[0022] As shown in Figures 1 and 2, the elevator shaft 40 is a reinforced concrete structure whose upper end is fixed to the superstructure 10 and which extends downward through the lower structure 20. The elevator shaft 40 is also called an elevator shaft. Because the upper end of the elevator shaft 40 is fixed to the superstructure 10, when horizontal energy such as from an earthquake is input, it acts as part of the base-isolated building together with the superstructure 10. For this reason, the elevator shaft 40 and the lower structure 20 surrounding the elevator shaft 40 are spaced apart to allow for the horizontal movement of the elevator shaft 40.

[0023] As shown in Figure 2, the elevator shaft 40 includes a wall portion 44 for forming an internal space 43 through which the elevator car 42 moves up and down, a bottom portion 46 that closes the internal space 43 at the lower end of the wall portion 44, and a plurality of tension members (51, 52) extending from the superstructure 10 towards the bottom portion 46 within the wall portion 44.

[0024] The wall section 44 is a prestressed concrete structure in which tensile force is applied to multiple tensioning members (51, 52). A prestressed concrete structure is a concrete structure in which prestress is applied by tensioning high-strength steel wires, stranded steel wires, or steel rods called PC steel and anchoring them to the ends of the concrete members. Because the wall section 44 is a prestressed concrete structure, cracks in the concrete structure caused by tensile stress due to the weight of the elevator shaft 40 can be prevented. In addition, because the wall section 44 is a prestressed concrete structure, the cross-sectional area of ​​the wall section 44 can be reduced, resulting in a space-saving elevator shaft 40.

[0025] Because the wall section 44 is a prestressed concrete structure, there are no seismic isolation bearings below the bottom section 46 (the space 22 below the elevator shaft 40). Therefore, the seismic isolation structure 1 does not require seismic isolation bearings below the elevator shaft 40, which is made of prestressed concrete, and thus a working space can be secured in the space 22 below the elevator shaft 40.

[0026] Multiple tension members (51, 52) can have their respective upper ends 55 fixed to the superstructure 10. By fixing the upper ends 55 to the superstructure 10, the weight of the elevator shaft 40 can be reliably transmitted to the superstructure 10 side. Multiple tension members (51, 52) may include multiple first tension members 51 and multiple second tension members 52 that are shorter than the first tension members 51. Multiple first tension members 51 extend from the superstructure 10 to the bottom 46. First tension member 5 Because the tension member 1 extends from the superstructure 10 to the bottom 46, the wall section 44 can receive compressive stress over its entire height H1. Therefore, the wall section 44 can prevent concrete cracking over its entire height H1. Multiple second tension members 52 extend from the superstructure 10 to a position higher than H2, which is half the height H1 of the wall section 44. The second tension members 52 have the same basic configuration as the first tension member 51, except that the height at which their lower ends 56 are fixed is different. By providing the second tension members 52, the upper part of the wall section 44 on the superstructure 10 side can be reinforced more than the lower part of the wall section 44 on the bottom 46 side. By reinforcing the superstructure 10 side, the bending rigidity and bending resistance of the wall section 44 during an earthquake can be increased.

[0027] The material of the first tensioning member 51 and the second tensioning member 52 can be a known PC (Prestressed Concrete) steel material. In this embodiment, a PC steel bar is used, but it may also be a PC steel wire or made of another metal.

[0028] As shown in Figure 3, the hoistway 40 has openings 48, 48 for entering and exiting the elevator. In this embodiment, openings 48, 48 are provided on both ends of the wall section 44 in the Y direction. The openings 48 are entrances and exits to the elevator car 42 (omitted in Figure 3). The two opposing wall sections 44 extend linearly along the Y direction, with the internal space 43 in between. No wall section 44 is provided in the opening 48, and the Y-direction ends of the wall section 44 form the ends of the opening 48. On the upper slab 13, a plurality of upper anchoring plates 53 and first tension members 51 and second tension members 52 are arranged along the wall section 44. In the wall section 44, it is preferable that the first tension member 51 is placed in the part of the plurality of tension members (51, 52) that is closest to the opening 48. This is to reinforce the area near the opening 48 where the wall section 44 is not continuous over the entire height H1.

[0029] As shown in Figure 4, the first tension member 51 is fixed at its lower end 56 to a lower fixing plate 54 anchored inside the bottom 46 with a nut 57, and at its upper end 55 to an upper fixing plate 53 anchored to the upper surface of the upper slab 13 with a nut 57. Known methods used for PC steel can be employed as means for fixing the first tension member 51 and the second tension member 52 (see Figure 2 for the second tension member 52). The upper slab 13 may include reinforced concrete beams that constitute the first floor. A tubular body 58 is provided around the first tension member 51 and the second tension member 52, spaced apart from them, separating the first tension member 51 and the second tension member 52 from the concrete that constitutes the wall 44. The tubular body 58 is made of metal or synthetic resin and has an inner diameter slightly larger than that of the first tension member 51 and the second tension member 52. By pulling the upper end 55 upward with a jack (not shown) and fixing the upper end 55 to the upper anchoring plate 53 with a nut 57, tensile forces act on the first tensioner 51 and the second tensioner 52 between the upper anchoring plate 53 and the lower anchoring plate 54, and compressive stress acts on the concrete between the upper anchoring plate 53 and the lower anchoring plate 54. It is preferable that this compressive stress be set to be equal to or greater than the tensile force acting on the wall section 44 due to the weight of the wall section 44 and the bottom section 46. Furthermore, this compressive stress can prevent cracking of the concrete constituting the wall section 44. The construction method of the elevator shaft 40 will be described later.

[0030] Multiple first tension members 51 can be arranged inside the vertical reinforcement bars 44a and horizontal reinforcement bars 44b that constitute the reinforced concrete structure of the wall section 44. That is, the vertical reinforcement bars 44a and horizontal reinforcement bars 44b are located close to the surface of the wall section 44, and the first tension members 51 are located in the center of the wall section 44. The first tension members 51 and the vertical reinforcement bars 44a and horizontal reinforcement bars 44b are arranged so as not to interfere with each other. Therefore, the wall section 44 has crack resistance and bending moment resistance due to the reinforcement by the vertical reinforcement bars 44a and horizontal reinforcement bars 44b and the compressive stress by the first tension members 51. Although not shown in the figures, second tension members 52 are also arranged inside the vertical reinforcement bars 44a and horizontal reinforcement bars 44b, similar to the first tension members 51.

[0031] The bottom portion 46 closes the internal space 43 at the lower ends of two opposing wall portions 44 that straddle the internal space 43. The bottom portion 46 is a reinforced concrete plane extending in the XY direction. The bottom portion 46 is This forms a space 22 below the elevator shaft 40 between it and the lower structure 20. The lower end 56 of the first tensioning member 51, which extends further downward from the lower end of the wall portion 44, is fixed to the concrete of the bottom portion 46 via a lower fixing plate 54 located inside the bottom portion 46.

[0032] The upper slab 13 is a reinforced concrete plan extending in the XY direction to which the upper end of the elevator shaft 40 is connected. The upper slab 13 may include steel. The upper slab 13 has an opening in the Z direction where it faces the bottom 46, and an internal space 43 is connected to the upper elevator shaft (not shown). An upper anchoring plate 53 is anchored to the upper surface of the upper slab 13, and the upper end 55 of the first tensioning member 51 protrudes through the upper anchoring plate 53. Additional concrete may be poured on top of the upper slab 13 to cover the upper end 55.

[0033] 3. Method of constructing elevator shafts The elevator shaft 40 can be constructed, for example, in the following order: construction of the base 46, construction of the wall section 44, and tensioning of the first tension member 51 and the second tension member 52. The elevator shaft 40 may be cast in place, or it may be precast and attached to the superstructure 10.

[0034] First, the construction of the base 46 involves reinforcing the base 46 and attaching the lower anchoring plate 54. The first tension member 51 is attached to the lower anchoring plate 54 with nuts 57, the pipe 58 is placed around the first tension member 51, and concrete is poured. Next, the construction of the wall section 44 involves placing vertical reinforcement 44a and horizontal reinforcement 44b above the base 46, and pouring concrete gradually from the base 46 side, for example in multiple pours. Also, as shown in Figure 2, the lower anchoring plate 54 is fixed at a predetermined position beyond the half height position H2 of the wall section 44, the second tension member 52 is fixed to the lower anchoring plate 54 with nuts in the same way as the first tension member 51, the pipe 58 is placed around the second tension member 52, and concrete is poured. The reinforcement work for the wall section 44 may be performed before pouring the concrete for the base 46, or continuously with the reinforcement work for the base 46. Next, tensioning of the first tension member 51 and the second tension member 52 is performed after the concrete of the upper slab 13 to which the upper anchoring plate 53 is fixed has been poured. Specifically, this is done by pulling the upper end 55 upward with a jack (not shown), and then fixing the upper end 55 to the upper anchoring plate 53 with a nut 57 to maintain the tensioned state of the first tension member 51 and the second tension member 52. Since the area around the first tension member 51 and the second tension member 52 is isolated from the concrete by the pipe body 58, tensile stress can be applied to the first tension member 51 and the second tension member 52 even after the concrete has been poured. After achieving the predetermined tension, grout material is introduced into the inside of the pipe body 58 to integrate the first tension member 51 and the second tension member 52 with the wall section 44. Also, since the upper end 55 protrudes from the upper slab 13, concrete is poured up to the height of the first floor surface to embed the upper end 55.

[0035] 4. Variations The elevator shaft 40a of the modified seismic isolation structure 1 will be explained using Figure 5. Figure 5 is a plan view of the modified elevator shaft 40a. The elevator shaft 40 shown in Figure 5 has basically the same configuration as the elevator shaft 40a explained in Figures 1 to 4, so the same reference numerals will be used to explain each component, and redundant explanations will be omitted.

[0036] As shown in Figure 5, the elevator shaft 40a has an opening 48 for elevator entry and exit on only one side in the Y direction. The wall portion 44 of the elevator shaft 40a is formed in a rectangular shape, enclosing the internal space 43, as shown by the dashed line, except for the opening 48. The first tension member 51 and the second tension member 52 are not provided on the side of the wall portion 44 where the opening 48 is formed and on the side opposite to that side. Of the multiple tension members (51, 52) provided on the wall portion 44, the first tension member 51 is positioned at the part closest to the opening 48.

[0037] The present invention is not limited to the embodiments described above, and various further modifications are possible. For example, the present invention may have a configuration substantially identical to the configuration described in the embodiments (e.g., function, This includes configurations that have the same method and results, or configurations that have the same purpose and effect. Furthermore, the present invention includes configurations in which non-essential parts of the configuration described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as the configuration described in the embodiments. Furthermore, the present invention includes configurations that add known technology to the configuration described in the embodiments. [Explanation of symbols]

[0038] 1... Seismic isolation structure, 10... Superstructure, 13... Upper slab, 20... Substructure, 22... Space, 30... Seismic isolation device, 32... Seismic isolation layer, 40, 40a... Hoistway, 42... Elevator car, 43... Interior space, 44... Wall section, 44a... Vertical reinforcement, 44b... Horizontal reinforcement, 46... Bottom, 48... Opening, 51... First tensioning member, 52... Second tensioning member, 53... Upper anchoring plate, 54... Lower anchoring plate, 55... Top end, 56... Bottom end, 57... Nut, 58... Pipe body, H1... Total height, H2... Half height position

Claims

1. Substructure and An upper structure supported on the lower structure via a seismic isolation device, A reinforced concrete elevator shaft, the upper end of which is fixed to the upper structure and which extends downward through the lower structure, Equipped with, The elevator shaft includes a wall portion for forming an internal space through which the elevator car moves up and down, a bottom portion that closes the internal space at the lower end of the wall portion, and a plurality of tensioning members extending from the upper structure toward the bottom portion within the wall portion. The wall portion is a prestressed concrete structure to which tensile force is applied to the plurality of tensioning members, thereby providing a seismic isolation structure.

2. In claim 1, A seismic isolation structure characterized in that the upper ends of each of the aforementioned tensioning members are fixed to the superstructure.

3. In claim 1 or claim 2, The plurality of tensioning members include a plurality of first tensioning members and a plurality of second tensioning members that are shorter than the first tensioning members. The plurality of first tension members extend from the upper structure to the bottom, A seismic isolation structure characterized in that the plurality of second tensioning members extend from the superstructure to a position higher than half the total height of the wall.

4. In claim 3, The aforementioned elevator shaft has an opening for entering and exiting the elevator. The wall portion is characterized in that the first tension member is positioned at the portion of the plurality of tension members closest to the opening.

5. In any one of claims 1 to 4, The aforementioned wall section is a seismic isolation structure characterized in that the plurality of tensioning members are arranged inside the vertical and horizontal reinforcement bars that constitute the reinforced concrete structure.

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