Construction method of base isolation layer of intermediate-story base-isolated building

Abstract

To provide a construction method of a base isolation layer of an intermediate-story base-isolated building that facilitates management of construction accuracy of a base isolation foundation structure and can reduce the number of days for construction at the time of construction of the intermediate-story base-isolated building provided with the base isolation layer.SOLUTION: A method of constructing a base isolation layer 12 of an intermediate-story base-isolated building 10 by installing a seismic isolator 14 in an upper part of a lower skeleton 11 and constructing an upper skeleton 13 in an upper part of the seismic isolator, comprises: erecting a foundation steel frame 16 for constructing the lower skeleton; then installing a precast member 21 provided with an installation surface 24 of the seismic isolator on the foundation steel frame such that the installation surface becomes horizontal at a predetermined height; then placing concrete 31 to construct the lower skeleton in a lower part of the precast member and installing the seismic isolator on an installation surface of the precast member to construct the upper skeleton.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a method for constructing a seismic isolation layer in a mid-story seismically isolated building. [Background technology]

[0002] Conventionally, when constructing the seismic isolation layer of a mid-floor seismically isolated building, a seismic isolation foundation structure is constructed using reinforced concrete or steel frames, seismic isolation devices are installed, and the upper structure is constructed on the seismic isolation devices. Patent Document 1 below proposes a structure using a precast concrete panel. In Patent Document 1, a lower frame (foundation frame) is constructed, a precast concrete plate is placed on a horizontal surface provided on the foundation slab, and the precast concrete plate and foundation slab are fixed together to construct a seismic isolation foundation structure. After that, a seismic isolation device is installed on the precast concrete plate, and the upper frame is constructed on the seismic isolation device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5458375 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional construction methods, after the construction of the lower structure, concrete was poured and hardened up to the floor of the seismic isolation layer to create a level installation surface before the seismic isolation devices and precast members could be installed. This posed the problem of requiring more construction days to build the seismic isolation layer than other floors. Furthermore, the accuracy of the installation surface for installing the precast members is significantly affected by the combined accuracy of the steel frame construction of the lower structure and the construction accuracy of the floor constructed on the seismic isolation layer, making it difficult to control the construction accuracy of the seismic isolation foundation structure.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a method for constructing a seismic isolation layer in an intermediate-floor seismic isolation building that makes it easy to manage the construction accuracy of the seismic isolation foundation structure and shortens the number of construction days when constructing an intermediate-floor seismic isolation building with a seismic isolation layer. [Means for solving the problem]

[0006] In order to solve the above problems, the method for constructing a seismic isolation layer in a mid-floor seismically isolated building according to the present invention is a method for constructing a seismic isolation layer in a mid-floor seismically isolated building by installing a seismic isolation device on top of a lower structure and constructing an upper structure on top of the seismic isolation device, and includes the steps of erecting a foundation steel frame for constructing the lower structure, installing a precast member having an installation surface for the seismic isolation device on the foundation steel frame so that the installation surface is horizontal at a predetermined height, installing the seismic isolation device on the installation surface of the precast member, and, after installing the seismic isolation device, pouring concrete to construct the lower structure and constructing the upper structure on top of the seismic isolation device.

[0007] According to the present invention, precast members provided with the installation surfaces for the seismic isolation devices are installed on the foundation steel frame so that the installation surfaces for the seismic isolation devices are level at a predetermined height. Therefore, there is no need to pour concrete into the seismic isolation layer to create a horizontal surface in advance for installing the precast members. This allows the precast members to be installed without having to construct the lower structure or wait for the concrete to harden. Furthermore, because the precast members are installed on the foundation steel frame so that the installation surfaces for the seismic isolation devices are level at a predetermined height, the installation surfaces can be easily positioned with precision. Therefore, the method for constructing the seismic isolation layer of a multi-story seismically isolated building according to the present invention makes it easier to manage the construction precision of the seismic isolation foundation structure and shortens the number of days required for construction.

[0008] In the present invention, a through hole may be formed in the precast member in advance, a fixing member may be placed in the through hole, one end of the fixing member may be placed in the through hole and the other end may be placed so as to protrude into the space on the lower structure side, and grout may be filled into the through hole to integrate the precast member and the fixing member.

[0009] In this way, the fixing members can be integrated with the precast members, and then by pouring concrete to construct the lower structure, the precast members can be easily integrated and fixed to the lower structure.

[0010] In the present invention, the precast member is placed on the foundation steel frame, and the height and inclination of the installation surface of the seismic isolation device are adjusted using the adjustment gap at the bottom of the precast member, and grout is filled into the adjustment gap to integrate the precast member and the foundation steel frame.

[0011] In this way, the height and inclination of the installation surface of the seismic isolation device in the precast member can be adjusted using the adjustment gap, thereby reliably improving the construction accuracy of the seismic isolation foundation structure. Moreover, because the adjustment gap is filled with grout to integrate the precast member and the foundation steel frame, even if the precast member is installed before the construction of the lower structure, it can be integrated and fixed to the lower structure.

[0012] In the present invention, the precast members may be installed on girders of the foundation steel frame. In this way, the precast members can be installed stably even if they are installed before the adjacent lower structure is constructed below. [Effects of the Invention]

[0013] According to the present invention, when constructing a mid-floor seismically isolated building with a seismic isolation layer, it is easier to manage the construction accuracy of the seismic isolation foundation structure and the number of construction days can be shortened. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic side view of a mid-story seismically isolated building constructed using a method for constructing a seismic isolation layer according to an embodiment of the present invention. [Figure 2]1 is a partial side view showing the vicinity of the top of a column in a foundation steel frame in a method for constructing a seismic isolation layer according to an embodiment of the present invention. FIG. [Figure 3] This is a partial side view showing the state in which precast members are placed on foundation steel frames in a method for constructing a seismic isolation layer according to an embodiment of the present invention. [Figure 4] This is a schematic plan view showing the state in which precast members are placed on foundation steel frames in a method for constructing a seismic isolation layer according to an embodiment of the present invention. [Figure 5] 1A and 1B show a precast member used in a method for constructing a seismic isolation layer according to an embodiment of the present invention, where FIG. 1A is a plan view and FIG. 1B is a longitudinal cross-sectional view. [Figure 6] This is a partial side view showing the state in which a seismic isolation device has been installed on a precast member in a method for constructing a seismic isolation layer according to an embodiment of the present invention. [Figure 7] 1 is a partial side view showing the state of constructing the lower structure in a method for constructing a seismic isolation layer according to an embodiment of the present invention. FIG. [Figure 8] This is a partial side view showing the state in which an upper body is constructed on a seismic isolation device in a method for constructing a seismic isolation layer according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 is a schematic side view of a mid-story seismically isolated building constructed in this embodiment. This mid-story seismically isolated building 10 has an upper frame 13 constituting the upper floor constructed above a lower frame 11 constituting the lower floor with a seismic isolation layer 12 interposed therebetween. Multiple seismic isolation devices 14 are installed in the seismic isolation layer 12. Each seismic isolation device 14 is firmly fixed to the lower frame 11 and the upper frame 13.

[0016] 2 is a partial side view showing the vicinity of the top of a column 17 in the foundation steel frame 16. The figure shows a portion where girders 18 arranged vertically and horizontally are joined to the top of one column 17 in mutually orthogonal directions.

[0017] To construct the seismic isolation layer 12, first, a foundation steel frame 16 is erected to construct the lower structure 11, as shown in Figure 2. The lower structure 11 is composed of a number of vertically arranged columns 17, horizontally arranged girders 18 spanning between adjacent columns 17, 17, reinforcing bars 19 arranged around the girders 18, and sub-girders (not shown).

[0018] Plates 22 for installing precast members 21 are joined to the tops of the columns 17 and to the upper surfaces of the girders 18 adjacent to the columns 17. The upper surfaces of the plates 22 are formed horizontally. In addition, a large number of reinforcing bars 19 are installed in a predetermined shape around the tops of the columns 17 and the peripheries of each girder 18.

[0019] FIG. 3 is a partial side view showing the state in which precast members 21 are placed on foundation steel frame 16, and FIG. 4 is a schematic plan view showing the state in which precast members 21 are placed on foundation steel frame 16.

[0020] After erecting the foundation steel frame 16, a plurality of precast members 21 are placed on the foundation steel frame 16, as shown in Fig. 3. In this embodiment, as shown in Fig. 4, each precast member 21 is placed on a plate 22 that is placed on the upper surfaces of the girders 18 that are arranged vertically and horizontally in mutually perpendicular directions, and on the tops of the columns 17 to which these girders 18 are joined in mutually perpendicular directions.

[0021] 5(a) is a plan view of the precast member 21, and (b) is a vertical cross-sectional view of the precast member 21. FIG. As shown in Figures 5(a) and 5(b), the precast member 21 is formed by embedding reinforcing bars 23 formed into a predetermined shape in concrete. An installation surface 24 for the seismic isolation device 14 is provided on the upper surface. A plurality of long nuts 25 with female threads for fixing the seismic isolation device 14 are embedded in this installation surface 24 at equal intervals in a substantially circular shape. An anchor bolt 26 is connected to each long nut 25. Before the precast member 21 is installed, a plurality of through holes 27 are provided vertically penetrating the member. The through holes 27 may be stepped holes with a larger diameter hole below a smaller diameter hole.

[0022] As shown in Figures 3 and 5(b), fixing members 28 are placed in each through hole 27 to fix the precast members 21 integrally with the lower structure 11 while they are placed on the foundation steel frame 16. The fixing members 28 are made of a member in which an anchoring plate 28a is joined to the end of a reinforcing bar 28b. The anchoring plate 28a at one end of the fixing member 28 is placed in the through hole 27 that has been provided in advance in the precast members 21, and the reinforcing bar 28b at the other end of the fixing member 28 is placed so that it protrudes into the space on the lower structure 11 side.

[0023] The precast member 21 is installed on the top of the girder 18 or the top of the column 17 of the foundation steel frame 16 so that the upper surface, which will be the installation surface 24 of the seismic isolation device 14, is at a predetermined height. At this time, the installation surface 24 of the precast member 21 is adjusted so that it is horizontal. To make the installation surface 24 horizontal at a predetermined height, for example, the precast member 21 may be placed on the foundation steel frame 16 with an adjustment gap provided in the precast member 21, and the height and inclination of the installation surface 24 of the precast member 21 may be adjusted by, for example, injecting grout into this gap.

[0024] Then, grout is filled into the through holes 27, and grout is also filled into the gap between the girder 18 and the precast member 21. This integrates the precast member 21 and the fixing member 28, and eliminates any gaps between the precast member 21 and the foundation steel frame 16, stabilizing them as a single unit.

[0025] FIG. 6 is a partial side view showing the state in which the seismic isolation device 14 is installed in the precast member 21. After installing a large number of precast members 21 on the foundation steel frame 16, the seismic isolation device 14 is installed on the installation surface 24 of each precast member 21, as shown in Figure 6. The installation surface 24 is arranged horizontally and is provided with a large number of long nuts 25. The seismic isolation device 14 is installed by placing it on the installation surface 24 and fastening it to the long nuts 25 with bolts. Note that when installing the seismic isolation device 14 on the precast members 21, concrete has not yet been poured for the lower structure 11.

[0026] FIG. 7 is a partial side view showing the state in which the lower body is being constructed. After the seismic isolation devices 14 are installed, concrete 31 is poured into each part of the lower structure 11 to construct the lower structure 11, as shown in Figure 7. Furthermore, concrete 31 is poured to construct the floor 32 of the seismic isolation layer 12 on top of the lower structure 11. The floor 32 of the seismic isolation layer 12 is constructed around the sides of the precast members 21.

[0027] FIG. 8 is a partial side view showing the state in which an upper body is constructed on the seismic isolation device 14. As shown in FIG. As shown in FIG. 8, an upper steel frame 15 for the upper skeleton 13 is erected above the seismic isolation device 14, and concrete is poured into each portion to construct the upper skeleton 13. The order in which the lower structure 11 and the upper structure 13 are constructed is arbitrary, and it is possible to proceed with the construction of both simultaneously, or to construct the upper structure 13 first and then the lower structure 11. Then, once the construction of the lower frame 11, the seismic isolation layer 12, and the upper frame 13 is completed, the mid-story seismically isolated building 10 can be constructed.

[0028] According to the construction method for the seismic isolation layer 12 of the mid-story seismic isolation building 10 of this embodiment, the precast members 21 provided with the installation surfaces 24 of the seismic isolation devices 14 are installed on the foundation steel frame 16 so that the installation surfaces 24 of the seismic isolation devices 14 are horizontal at a predetermined height. Therefore, there is no need to pour concrete 31 into the seismic isolation layer 12 to create a horizontal surface for installing the precast members 21 in advance. This allows the precast members 21 to be installed without waiting for the construction of the lower structure 11 or the hardening of the concrete 31. Moreover, because the precast members 21 are installed on the foundation steel frame 16 so that the installation surfaces 24 of the seismic isolation devices 14 are horizontal at a predetermined height, the installation surfaces 24 can be easily and accurately positioned. This makes it easier to manage the construction accuracy of the seismic isolation foundation structure and shortens the number of days required for construction.

[0029] In the above embodiment, a through hole 27 is provided in advance in the precast member 21 and a fixing member is placed therein, one end of the fixing member 28 is placed in the through hole 27 and the other end is placed so as to protrude into the space on the lower structure 11 side, and grout is filled into the through hole 27 to integrate the precast member 21 and the fixing member 28. Therefore, the fixing member 28 can be integrated with the precast member 21, and then by pouring concrete 31 to construct the lower structure 11, the precast member 21 can be easily integrated with the lower structure 11 and fixed in place.

[0030] In the above embodiment, the precast member 21 is placed on the foundation steel frame 16, and the height and inclination of the installation surface 24 of the seismic isolation device 14 are adjusted using the adjustment gap at the bottom of the precast member 21, and grout is filled into the gap to integrate the precast member 21 and the foundation steel frame 16. Therefore, the height and inclination of the installation surface 24 of the seismic isolation device 14 in the precast member 21 can be adjusted by using the adjustment gap, thereby reliably improving the construction accuracy of the seismic isolation foundation structure. Moreover, because grout is filled into the gap to integrate the precast member 21 and the foundation steel frame 16, even if the precast member 21 is installed before the construction of the lower structure 11, the precast member 21 can be integrated and fixed to the lower structure 11.

[0031] In the above embodiment, the precast members 21 are installed on the girders 18 of the foundation steel frame 16. Therefore, even if the precast members 21 are installed before the adjacent lower structure 11 below is constructed, the precast members 21 can be installed stably.

[0032] The above embodiment can be modified as appropriate within the scope of the present invention. For example, in the above embodiment, the precast member 21 was installed at the upper end of the foundation steel frame 16, and then concrete was poured to construct the lower structure 11, but it is also possible to construct the areas other than those adjacent to and below the precast member 21 at the same time as or before installing the precast member 21.

[0033] Furthermore, in the above embodiment, a through hole 27 is provided in the precast member 21 in advance, and after the precast member 21 is placed on the foundation steel frame, the fixing member 28 is placed in the through hole 27 and filled with grout, but this is not particularly limited, and the precast member 21 may be fabricated with one end of the fixing member 28 already buried.

[0034] Furthermore, in the above embodiment, an example was described in which the height and inclination of the installation surface 24 of the seismic isolation device 14 was adjusted by placing a precast member 21 on the foundation steel frame 16 and filling the gap at the bottom with grout, but the height and inclination of the installation surface 24 of the seismic isolation device 14 of the precast member 21 may also be adjusted by other methods.

[0035] In addition, in the above embodiment, an example was described in which each precast member 21 was placed on the portion where the girders 18 and columns 17 arranged vertically and horizontally in the foundation steel frame 16 were joined perpendicularly to each other, but the arrangement of the precast members 21 may be set appropriately, and they may also be placed on a single girder 18. [Explanation of symbols]

[0036] 10 Mid-floor seismically isolated building 11 Lower structure 12 Seismic isolation layer 13 Upper frame 14 Seismic isolation device 15 Upper steel frame 16 Foundation steel frame 17 pillars 18 Large beam 19 Reinforced concrete 21 Precast members 22 Plate 23 Reinforced concrete 24 Installation surface 25 Long Nut 26 Anchor bolt 27 Through hole 28 Fixing member 28a Fixing plate 28b Reinforced concrete 31 Concrete 32 beds

Claims

1. A method for constructing a seismic isolation layer in a mid-story seismically isolated building by installing a seismic isolation device on top of a lower frame and constructing an upper frame on top of the seismic isolation device, A step of erecting a foundation steel frame for constructing the lower structure; a step of installing a precast member provided with an installation surface for the seismic isolation device on the foundation steel frame so that the installation surface is horizontal at a predetermined height; a step of installing the seismic isolation device on the installation surface of the precast member; A method for constructing a seismic isolation layer in a mid-story seismically isolated building, comprising the steps of: after installing the seismic isolation device, pouring concrete to construct the lower structure, and constructing the upper structure on top of the seismic isolation device.

2. A method for constructing a seismic isolation layer in a mid-story seismically isolated building as described in claim 1, comprising the steps of: forming a through hole in the precast member in advance; placing a fixing member in the through hole; placing one end of the fixing member in the through hole and the other end so as to protrude into the space on the lower structure side; and filling the through hole with grout to integrate the precast member and the fixing member.

3. A method for constructing a seismic isolation layer in a mid-story seismically isolated building as described in claim 1, wherein the precast members are placed on the foundation steel frame, and the height and inclination of the installation surface of the seismic isolation device are adjusted using an adjustment gap at the bottom of the precast members, and grout is filled into the adjustment gap to integrate the precast members and the foundation steel frame.

4. 2. A method for constructing a seismic isolation layer in a mid-story seismically isolated building according to claim 1, wherein the precast members are installed on girders in the foundation steel frame.

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