JP4929363B2 - Base-isolated structure - Google Patents

Description

  The present invention relates to a base-isolated structure.

  A leveling layer made of concrete or mortar is formed on the ground, and a concrete foundation is supported on the leveling layer via a vinyl chloride sheet. Between the vinyl chloride sheet and the leveling layer due to rolling due to an earthquake, Conventionally, a base-isolated structure has been proposed in which a building is made to be isolated by sliding.

Japanese Patent Laid-Open No. 11-141183

  However, since both the leveling layer and the concrete foundation are hard, if the load-bearing wall of the building is subjected to a horizontal force due to the rolling due to the earthquake, the surface between the leveling layer and the concrete foundation in the force transmission process. There is a problem that the pressure varies, which causes a variation in resistance on the sliding surface, causing a rotational movement in the building and increasing the response displacement.

  In view of the above-described problems, the present invention effectively suppresses the rotational movement of a building during base isolation in a base-isolated structure that causes the building to slip by causing a slip beneath the base during an earthquake. It is an object to provide a seismic isolation structure under the foundation.

  The above problem is that the concrete foundation of the building is supported on the ground via the foamed resin plate, and the upper and lower sliding sheets in an overlapped state are interposed between the foamed resin plate and the ground foundation, The problem is solved by a base-isolated structure, which is characterized in that the building is isolated from the base by sliding between the upper and lower sliding seats due to the rolling due to the earthquake.

  In this structure, when the building's load-bearing wall receives a horizontal force due to rolling due to an earthquake, the surface pressure between the foamed resin plate and the ground foundation is reduced by the spring action in the vertical direction of the foamed resin plate in the force transmission process. The variation is alleviated, the resistance force on the sliding surface between the upper and lower sliding sheets is made constant, and it is possible to effectively suppress the building from rotating during seismic isolation.

  Moreover, between the foamed resin plate and the ground foundation, the upper and lower sliding sheets in an overlapped state are interposed, so that the building slides between the upper and lower sliding sheets so that the building is seismically isolated, Smooth sliding can be realized, and the foamed resin plate can be prevented from being damaged by the concrete foundation.

  In addition, by adopting the above-described foamed resin plate, it is possible to alleviate pitching caused by an earthquake or environmental vibration by the spring action in the vertical direction of the foamed resin plate.

  Furthermore, in this structure, since the foamed resin plate is provided on the sliding surface and the concrete foundation of the building is provided thereon, even if the foamed resin plate is deformed by the load of the building, the upper surface portion of the foamed resin plate is provided. Since the lower surface portion of the foamed resin plate that becomes the sliding surface is not deformed only by deformation, the sliding surface is not affected at the time of seismic isolation.

  Since the present invention is as described above, in a base-isolation structure that causes the building to slip by causing a slip beneath the foundation during an earthquake, it effectively suppresses the rotational movement of the building during the seismic isolation. be able to. In addition, the foamed resin plate is not damaged by the concrete foundation during the seismic isolation, and the pitching caused by the earthquake or environmental vibration can be reduced. Furthermore, seismic isolation performance can be exhibited without being affected by deformation of the foamed resin plate.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side view and FIG. (B) is an enlarged exploded side view of a part A in FIG.

  Next, embodiments of the present invention will be described with reference to the drawings.

  In the base-isolated structure of the embodiment shown in FIG. 1, 1 is a concrete foundation of a building, 2 is a ground, a ground foundation 3 is provided on the ground 2, and a foam is formed on the ground foundation 3. The concrete foundation 1 is supported via a foamed resin plate 4 made of polypropylene, foamed polystyrene, or the like. Between the foamed resin plate 4 and the ground foundation 3, the upper and lower sliding sheets 5, 5 overlapped with each other. Is installed, and the building is made to be seismically isolated by sliding between the upper and lower sliding sheets 5 and 5 due to the rolling due to the earthquake.

  The planar shape of the foamed resin plate 4 is set to be substantially the same as or larger than the bottom surface of the concrete foundation 1 of the building provided on the foamed resin plate.

  The sliding sheets 5 and 5 are made of, for example, a fluororesin-based sheet. The sliding sheets 5 and 5 are respectively formed on the upper surface side of the upper sliding sheet 5 and the lower surface side of the lower sliding sheet 5 due to moisture, unevenness of the ground, etc. Protective sheets 6 and 6 that protect 5 and 5 are provided as necessary.

  The thickness dimension of the foamed resin plate 4 is, for example, 50 mm, the total thickness dimension of the sheets 5, 5, 6, 6 is, for example, about 6 mm, and the thickness dimension of the footing portion of the concrete foundation 1 is, for example, 155 mm. It is.

  In the above base-isolated structure, when the bearing wall of the building receives a horizontal force due to the rolling due to the earthquake, the foamed resin plate 4 and the ground foundation are caused by the spring action in the vertical direction of the foamed resin plate 4 in the force transmission process. 3 is mitigated, the resistance force on the sliding surface between the upper and lower sliding sheets 5 and 5 is made constant, and the building is effectively prevented from rotating during seismic isolation. be able to.

  In addition, the upper and lower sliding sheets 5, 5 are interposed between the foamed resin plate 4 and the ground foundation 3, and the building is isolated by causing slippage between the upper and lower sliding sheets 5, 5. Thus, smooth sliding can be realized, and the foamed resin plate 4 can be prevented from being damaged by the ground foundation 3.

  In addition, by adopting the foamed resin plate 4 as described above, the vertical vibration caused by environmental vibrations such as earthquakes and traffic vibrations can be mitigated by the spring action of the foamed resin plate 4 in the vertical direction.

  Furthermore, in this structure, since the foamed resin plate is provided on the sliding surface and the concrete foundation of the building is provided thereon, even if the foamed resin plate is deformed by the load of the building, the upper surface portion of the foamed resin plate is provided. Since the lower surface portion of the foamed resin plate that becomes the sliding surface is not partially deformed only by deformation, there is no influence on the sliding surface during the base isolation.

DESCRIPTION OF SYMBOLS 1 ... Concrete foundation 2 ... Ground 3 ... Ground foundation 4 ... Foamed resin board 5 ... Sliding sheet

Claims (1)

The concrete foundation of the building is supported on the ground via the foamed resin plate, and the upper and lower sliding sheets in an overlapped state between the foamed resin plate and the ground foundation are on the upper surface side of the upper sliding sheet, And a lower sheet side of the lower sliding sheet is provided in a mode in which a protective sheet for protecting the sliding sheet is provided as necessary, and the foamed resin plate and the ground foundation are provided by a spring action in the vertical direction of the foamed resin plate. The variation in surface pressure between the two is reduced, and the building is made to be seismically isolated by generating a slip while suppressing the rotational movement of the building between the upper and lower sliding seats due to the rolling due to the earthquake. The base-isolated structure.

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