Seismic isolation foundation structure

Abstract

To provide a base isolation foundation structure which can be constructed with high accuracy and has excellent earthquake resistance.SOLUTION: The seismic isolation foundation structure 1 includes a laminated rubber bearing 20, a precast reinforced concrete upper foundation 30 provided on the laminated rubber bearing 20, a connection part steel beam 40 arranged on a beam support part 33 projecting upward from an upper surface of the upper foundation 30, and a concrete foundation joint part 50 constructed including the upper foundation 30 and a part of the connection part steel beam 40. Thus, since the laminated rubber bearing 20, the upper foundation 30 and the connection part steel frame beam 40 can be firmly integrated, the base isolation foundation structure 1 superior in earthquake resistance can be provided.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a seismic isolation foundation structure equipped with a seismic isolation device. [Background technology]

[0002] BACKGROUND ART Seismic isolation structures equipped with seismic isolation devices have been proposed in the past (see Patent Documents 1 to 3). Patent Document 1 shows a seismic isolation structure comprising a seismic isolation device, a precast concrete upper foundation placed on the seismic isolation device, a precast concrete lower rising foundation placed below the seismic isolation device, and a column base connected to the top of the upper foundation. Patent Document 2 shows a seismic isolation foundation structure comprising a lower foundation, a seismic isolation device provided on the lower foundation, and a precast concrete upper foundation provided on the seismic isolation device.

[0003] Patent document 3 shows a seismic isolation foundation structure comprising a lower seismic isolation foundation made of precast concrete, a seismic isolation device installed on the lower seismic isolation foundation, an upper seismic isolation foundation made of precast concrete installed on the seismic isolation device, and an upper structure (steel beams and steel columns) installed on the upper seismic isolation foundation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5232106 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-91943 [Patent Document 3] Patent No. 7165548 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a seismic isolation foundation structure that can be constructed with high precision and has excellent earthquake resistance. [Means for solving the problem]

[0006] The seismic isolation foundation structure of the first invention (for example, the seismic isolation foundation structures 1 and 1A described below) is a seismic isolation foundation structure equipped with a seismic isolation device (for example, the laminated rubber bearing 20 and the elastic sliding bearing 60 described below), and is characterized in that it comprises the seismic isolation device, a concrete upper foundation (for example, the upper foundations 30 and 70 described below) provided on the seismic isolation device, a beam member (for example, the joint steel beam 40 described below) placed on a beam support portion (for example, the beam support portion 33 described below) protruding upward from the top surface of the upper foundation, and a concrete foundation joint (for example, the foundation joint 50 described below) constructed including the upper foundation and a portion of the beam member.

[0007] According to this invention, a concrete upper foundation is placed on the seismic isolation device, and a beam member is placed on the beam support of the upper foundation. In this state, concrete is poured to cover the upper foundation and a part of the beam member to form a foundation joint. This allows the seismic isolation device, upper foundation, and beam member to be firmly integrated, providing a seismic isolation foundation structure with excellent earthquake resistance. In addition, a concrete upper foundation is placed on the seismic isolation device, and beam members are placed on the beam support parts of the upper foundation, and concrete is then poured in this state to create a reinforced concrete foundation joint.In this way, because the upper foundation is made of concrete, a highly accurate seismic isolation foundation structure can be constructed in a short construction period.

[0008] The seismic isolation foundation structure of the second invention is characterized in that the upper foundation and the beam support portion are made of precast concrete and formed as a single unit. According to this invention, the upper foundation and the beam support portion are made of precast concrete, which is integrally formed, so that a highly accurate seismic isolation foundation structure can be constructed in a short construction period. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a seismic isolation foundation structure that can be constructed with high precision and has excellent earthquake resistance. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a vertical cross-sectional view of a seismic isolation foundation structure according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of the area surrounded by dashed line A in the seismic isolation foundation structure of FIG. 1. [Figure 3] 3 is a flowchart of the construction procedure of the seismic isolation foundation structure of the first embodiment. [Figure 4] FIG. 2 is an explanatory diagram of the construction procedure of the seismic isolation foundation structure of the first embodiment (part 1, state after the lower foundation is constructed in the seismic isolation pit). [Figure 5] FIG. 2 is an explanatory diagram of the construction procedure of the seismic isolation foundation structure of the first embodiment (part 2, state in which the laminated rubber bearing is installed on the lower foundation). [Figure 6] FIG. 10 is an explanatory diagram of the construction procedure of the seismic isolation foundation structure of the first embodiment (part 3, state in which the upper foundation is installed on the laminated rubber bearings). [Figure 7] FIG. 10 is an explanatory diagram of the construction procedure of the seismic isolation foundation structure of the first embodiment (part 4, state in which the joint steel beam is placed on the beam support part of the upper foundation). [Figure 8] FIG. 6 is a vertical cross-sectional view of a portion of a seismic isolation foundation structure according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention is a seismic isolation foundation structure in which a concrete upper foundation is placed on a seismic isolation device, a beam member is placed on the beam support part of the upper foundation, and in this state, concrete is poured to include the upper foundation and part of the beam member, thereby constructing a foundation joint. The first embodiment is a seismic isolation foundation structure in which a seismic isolation device (laminated rubber bearing) is joined to an upper foundation made of precast reinforced concrete (Figs. 1 to 7). The second embodiment is a seismic isolation foundation structure in which a seismic isolation device (elastic sliding bearing) is joined to a flange plate of the upper foundation (Fig. 8). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description of the embodiments, the same components will be denoted by the same reference numerals, and the description thereof will be omitted or simplified.

[0012] [First embodiment] Fig. 1 is a vertical cross-sectional view of a base-isolated foundation structure 1 according to a first embodiment of the present invention. Fig. 2 is an enlarged view of a portion of the base-isolated foundation structure 1 in Fig. 1 surrounded by a dashed line A. The seismic isolation foundation structure 1 is a seismic isolation foundation for a building, and comprises a lower foundation 10 as a reinforced concrete foundation provided in a seismic isolation pit 2, a laminated rubber bearing 20 as a seismic isolation device installed on the lower foundation 10, a precast reinforced concrete upper foundation 30 provided on the laminated rubber bearing 20, a joint steel beam 40 as a beam member arranged on the upper foundation 30, and a foundation joint 50 constructed including the upper foundation 30 and the joint steel beam 40.

[0013] The seismic isolation pit 2 is made of reinforced concrete and includes piles 3, foundation footings 4 provided on the piles 3, and foundation beams 5 joined to the foundation footings 4. The lower foundation 10 is a reinforced concrete structure constructed by pouring concrete on-site onto the foundation footing 4, and reinforcing bars 11 are arranged in a cage-like pattern inside the lower foundation 10. A lower base plate 12 is driven into the upper surface of the lower foundation 10. Long nuts 13 are provided in a circular shape at predetermined intervals on the lower base plate 12, and anchor bars 14 are screwed into the lower ends of the long nuts 13. In addition, a plurality of anchor studs 15 are provided on the underside of the lower base plate 12, and these anchor studs 15 are embedded in the lower foundation 10.

[0014] The laminated rubber bearing 20 includes a laminated rubber 21 , a lower flange 22 located below the laminated rubber 21 , and an upper flange 23 located above the laminated rubber 21 . The laminated rubber 21 is made up of steel plates and rubber laminated alternately. The upper and lower flanges 22, 23 are provided with bolt insertion holes 24, 25 at predetermined intervals along their peripheries as through holes for inserting mounting bolts 26, 27. A mounting bolt 26 is inserted into the bolt insertion hole 24 of the lower flange 22 and is screwed into a long nut 13 provided on the lower base plate 12 of the lower foundation 10.

[0015] The upper foundation 30 is made of precast reinforced concrete. The lower ends of the column main reinforcements 31 and the lower parts of the cage-shaped reinforcing bars 32 are buried in this upper foundation 30, and a rectangular or circular plate 90 is attached to the lower ends of the column main reinforcements 31 to increase the anchorage strength of the column main reinforcements 31 to the upper foundation 30. The upper ends of the column main reinforcements 31 and the reinforcing bars 32 protrude upward from the top surface of the upper foundation 30. In addition, a concrete beam support portion 33 is formed in the center of the top surface of the upper foundation 30, protruding upward.

[0016] Long nuts 34 as female threads are embedded in a circular shape at predetermined intervals in the center of the underside of the upper foundation 30. Anchor bars 35 are threadedly engaged with the upper ends of the long nuts 34, and protrude upward from the top surface of the upper foundation 30. A mounting bolt 27 is threaded into the bolt insertion hole 25 of the upper flange 23 of the laminated rubber bearing 20 and is then threaded into a long nut 34 of the upper foundation 30 . The connection steel beam 40 is an H-shaped steel beam that is substantially cross-shaped in plan view. A steel girder 41 made of an H-shaped steel is joined to the end of this connection steel beam 40.

[0017] The procedure for constructing the seismic isolation foundation structure 1 will be described with reference to the flowchart of FIG. In step S1, as shown in Figure 4, a lower foundation 10 is constructed on the seismic isolation pit 2. Specifically, reinforcement is arranged in the seismic isolation pit 2 and a lower base plate 12 is set in place. Next, side forms (not shown) are erected and filled with concrete under pressure, and the formwork is removed after a predetermined period of curing. At this time, the position and inclination of the lower base plate are measured to ensure that they are within predetermined control values. In step S2, as shown in Fig. 5, the laminated rubber bearing 20 is installed on the lower foundation 10. Specifically, the laminated rubber bearing 20 is placed on the lower base plate 12 of the lower foundation 10, and the lower flange 22 of the laminated rubber bearing 20 is fixed to the lower base plate 12 of the lower foundation 10 with mounting bolts 26.

[0018] In step S3, as shown in Fig. 6, the upper foundation 30 is placed on the laminated rubber bearing 20. Specifically, the upper foundation 30 is placed on the laminated rubber bearing 20, and the upper flange 23 of the laminated rubber bearing 20 is fixed to the long nut 34 of the upper foundation 30 with the mounting bolts 27, thereby joining the laminated rubber bearing 20 and the upper foundation 30. In step S4, as shown in Fig. 7, the joint steel beam 40 is placed on the beam support portion 33 of the upper foundation 30. At this time, the height of the beam support portion 33 is measured, and if the beam support portion 33 is higher than a predetermined control value, the upper surface of the beam support portion 33 is filed to adjust the height of the beam support portion 33. On the other hand, if the beam support portion 33 is lower than the predetermined control value, a filler plate, which is a steel plate, is placed on the upper surface of the beam support portion 33 to adjust the height of the beam support portion 33.

[0019] In step S5, the steel girder 41 is joined to the steel beam 40 at the connection section, and reinforcement is arranged at the foundation joint 50. Specifically, the reinforcement at the foundation joint 50 involves arranging hoop reinforcement 36 on the main column reinforcement 31 protruding from the upper foundation 30, and arranging cross reinforcement 37 on the reinforcing bars 32 protruding from the upper foundation 30. In step S6, the foundation joint 50 is constructed. Specifically, a formwork (not shown) is erected surrounding the upper foundation 30 and a portion of the connection steel beam 40, and concrete is poured inside the formwork, and the formwork is removed after curing for a predetermined period of time, thereby constructing the foundation joint 50. In this way, the seismic isolation foundation structure 1 as shown in FIG. 1 is constructed.

[0020] According to this embodiment, the following effects are obtained. (1) A precast reinforced concrete upper foundation 30 is placed on the laminated rubber bearings 20, and a steel beam 40 for the connection section is placed on the beam support section 33 of the upper foundation 30. In this state, concrete is poured to cover the upper foundation 30 and a part of the steel beam 40 for the connection section, thereby constructing the foundation joint 50. This allows the laminated rubber bearings 20, upper foundation 30, and steel beam 40 to be firmly integrated, thereby providing a seismic isolation foundation structure 1 with excellent earthquake resistance. Furthermore, long nuts 34 with anchor bars are embedded in the upper foundation 30 of precast reinforced concrete construction, and mounting bolts 27 inserted into bolt insertion holes 25 in the upper flange 23 of the laminated rubber bearing 20 are screwed onto the long nuts 34, thereby joining the laminated rubber bearing 20 and the upper foundation 30. This allows the laminated rubber bearing 20 and the upper foundation 30 to be joined with high precision. Furthermore, a precast reinforced concrete upper foundation 30 is placed on the laminated rubber bearings 20, and a joint steel beam 40 is placed on the beam support section 33 of the upper foundation 30, and concrete is poured in this state to construct a reinforced concrete foundation joint 50. In this way, because the upper foundation 30 is made of precast reinforced concrete, a highly accurate seismic isolation foundation structure 1 can be constructed in a short construction period.

[0021] (2) The lower end of the column main reinforcement 31 is embedded in the upper foundation 30 on the laminated rubber bearing 20, so that the column and the seismic isolation foundation structure 1 can be firmly joined. (3) Since the laminated rubber bearing 20 is installed on the lower foundation 10, it is possible to stably absorb seismic forces and reduce the seismic forces acting on the structure on the upper foundation 30.

[0022] Second Embodiment FIG. 8 is a vertical cross-sectional view of a portion of a seismic isolation foundation structure 1A according to the second embodiment of the present invention. In this embodiment, the structure of the seismic isolation device 60 and the structure of the upper foundation 70 are different from those in the first embodiment, but the rest of the structure is the same as that in the first embodiment. That is, the seismic isolation device of this embodiment is an elastic sliding bearing 60. The elastic sliding bearing 60 includes a sliding member 61 and a sliding member 62 that can slide on the sliding member 61. The sliding member 61 includes a reinforcing plate 63 and a sliding plate 64 provided on the reinforcing plate 63. The sliding member 62 includes a laminated rubber 65 and an upper flange 66 provided on the laminated rubber. The lower surface of the laminated rubber 65 is capable of sliding on the sliding plate 64. The upper flange 66 is provided with a bolt insertion hole 67 as a through hole.

[0023] The upper foundation 70 is made of precast reinforced concrete. The lower ends of the column main reinforcements and the lower parts of the reinforcing bars 32 (not shown) are buried in this upper foundation 70, and rectangular or circular plates 90 are attached to the lower ends of the column main reinforcements 31 to increase the anchoring strength of the column main reinforcements 31 to the upper foundation 30. The upper ends of the column main reinforcements 31 and the reinforcing bars 32 protrude upward from the top surface of the upper foundation 70. Furthermore, a beam support portion (not shown) that protrudes upward is formed in the center of the top surface of the upper foundation 70.

[0024] A height adjustment portion 71 that protrudes downward is provided at the center of the lower surface of the upper foundation 70. The height adjustment section 71 includes a flange plate 72, a cylindrical steel pipe 73 provided on the flange plate 72, and a concrete body 74 filled in the steel pipe 73. The flange plate 72 is provided with a plurality of anchor studs 75, which are embedded in the concrete body 74. The flange plate 72 has bolt insertion holes 76 formed at its edge as through holes.

[0025] A rectangular ring-shaped base plate 77 is provided in the center of the underside of the upper foundation 70, and the steel pipes 73 of the height adjustment section 71 are joined to this base plate 77. A plurality of anchor studs 78 are provided on the base plate 77, and these anchor studs 78 are embedded in the upper foundation 70. The elastic sliding support 60 and the upper foundation 70 are joined by inserting an attachment bolt 79 into the bolt insertion hole 76 of the upper foundation 70 and the bolt insertion hole 67 of the elastic sliding support 60, and screwing a nut 80 onto this attachment bolt 79. According to this embodiment, the same effects as those (1) to (3) above are obtained.

[0026] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. In the second embodiment described above, the base plate 77 is provided in the center of the lower surface of the upper foundation 70, but this is not limiting, and the base plate may not be provided. In addition, in each of the above-described embodiments, the plate 90 is provided at the lower end of the column main reinforcement 31 embedded in the upper foundation 30, but this is not limiting, and a nut may be attached to the lower end of the column main reinforcement 31, or the lower end of the column main reinforcement 31 may be processed into a hook.

[0027] Furthermore, in each of the above-described embodiments, laminated rubber bearings 20 or elastic sliding bearings 60 are used as seismic isolation devices (isolators), but this is not limiting, and the seismic isolation devices may also be viscous bearings that absorb earthquake energy using viscous dampers, hydraulic bearings that absorb earthquake energy using hydraulic cylinders or dashpots, or spring bearings that absorb earthquake energy using springs. Furthermore, in each of the above-described embodiments, the upper foundation 30 is made of precast reinforced concrete, but this is not limiting, and the upper foundation may be made of reinforced concrete or concrete, in which concrete is poured at the construction site. Furthermore, in each of the above-described embodiments, the beam member is a joint steel beam 40, and a steel girder 41 is joined to this joint steel beam 40, but this is not limited to this, and the beam member may also be a reinforced concrete beam or a steel-reinforced concrete beam. [Explanation of symbols]

[0028] 1, 1A...Seismic isolation foundation structure 2...Seismic isolation pit 3...Pile 4...Foundation footing 5…Foundation beam 10... Lower foundation (base) 11... Steel bar 12... Lower base plate 13...Long nut 14...Anchor bar 15...Anchor stud 20...Laminated rubber bearing (seismic isolation device) 21...Laminated rubber 22...Lower flange 23...Upper flange 24...Bolt insertion hole 25...Bolt insertion hole (through hole) 26...Mounting bolt 27...Mounting bolt 30...Upper foundation 31...Column main reinforcement 32...Reinforcing bar 33...Beam support part 34...Long nut (female threaded part) 35...Anchor bar 36...Hoop bar 37...Horizontal bar 40... Steel beam at joint (beam member) 41... Steel girder 50... Foundation joint 60... Elastic sliding bearing (seismic isolation device) 61... Sliding member 62... Sliding member 63... Reinforcing plate 64... Sliding plate 65... Laminated rubber 66... ​​Upper flange 67...Bolt insertion hole (through hole) 70...Upper foundation 71...Height adjustment part 72...Flange plate 73...Steel pipe 74...Concrete body 75...Anchor stud 76...Bolt insertion hole (through hole) 77...Base plate 78...Anchor stud 79...Mounting bolt 80...Nut 90...Plate

Claims

1. A seismic isolation foundation structure equipped with a seismic isolation device, The seismic isolation device; a concrete upper foundation provided on the seismic isolation device; a beam member disposed on a beam support portion protruding upward from the upper surface of the upper foundation; and a concrete foundation joint constructed including the upper foundation and a portion of the beam member.

2. 2. The seismic isolation foundation structure according to claim 1, wherein the upper foundation and the beam support portion are integrally formed of precast concrete.

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