JP4567493B2 - Seismic isolation system for buildings over railway tracks - Google Patents

Description

  The present invention relates to a seismic isolation and vibration isolation structure system for buildings over railway tracks.

It is expected that buildings using railway tracks will become more and more necessary in the future in terms of business development related to railway operators and urban redevelopment. Such buildings need to have higher seismic performance than ordinary buildings because they straddle the track.
Conventionally, a proposal for a seismic isolation / vibration isolation building having a seismic isolation function and a function of blocking fine vibration and solid propagation sound propagating from railways and roads around the building has been disclosed in Non-Patent Document 1 below. , 2.
Ando: “Research and development of seismic isolation systems for buildings (10)” Kashima Technical Research Institute Annual Report, No. 39, pages 141-147, published on October 31, 1991 Nakamura et al: “Development of seismic isolation and vibration isolation system using thick laminated rubber (Part 1)”, Obayashi Institute of Technology Report No. 42, pages 15-22 Teramura et al: “Development of seismic isolation and vibration isolation system using thick laminated rubber (Part 2)”, Obayashi Institute of Technology Report No. 42, pp. 23-26

However, seismic isolation structure is advantageous to improve the seismic performance when building buildings over railway tracks, but it is difficult to construct a rigid underground beam that connects the foundations to straddle the track. It is difficult to install a seismic isolation layer on the foundation like a building.
Furthermore, since vibration generated during train traveling propagates through the building, it is difficult to secure a space that requires high quality with low noise and vibration, such as a hotel, in a general structure.

  In view of the above circumstances, the present invention improves the seismic performance and improves the vibration isolation effect against train vibration by softening the vertical rigidity of the base isolation layer. The object is to provide a structural system.

In order to achieve the above object, the present invention provides
[1] In a seismic isolation system for a building over the track where the track is laid at the bottom of the building foundation, it is connected to a foundation pile without an underground beam to serve as a passage for a railway vehicle. And a laminated rubber that is built on the foundation pillar including the station facility and is placed on the pillar of the foundation of the multi-layered building built above the railroad track and has a soft vertical rigidity. and isolation layer is disposed between the upper and lower beams seismic isolation layer arranged the laminated rubber, and characterized by comprising a viscoelastic dampers sliding bearing mechanism is incorporated.

  [2] In the seismic isolation system for buildings above the railway line according to [1], the viscoelastic damper is disposed in a central portion of the seismic isolation layer.

According to the present invention, the following effects can be achieved.
(1) Since the seismic isolation layer with laminated rubber was provided on the foundation of the building constructed on the foundation pillar, the seismic performance could be improved and the seismic isolation layer with laminated rubber Anti-vibration effect against train vibration can be enhanced by softening the rigidity in the vertical direction.
(2) Improve the vibration isolation effect by installing a viscoelastic damper in the base isolation layer to reduce the vibration amplification of the structure above the base isolation layer generated by softening the vertical rigidity of the base isolation layer be able to.

  (3) When a building includes a station facility, there are many cases where a structure such as a pedestrian deck (a pedestrian plaza or passage) is adjacent to the building. Large scale expansion joints (expansion joints) that take into account the relative deformation at the time of an earthquake are required at the boundary with the structure. On the other hand, in the case of an intermediate layer seismic isolation structure, considering that the displacement below the seismic isolation layer is the same as the displacement of the adjacent structure, a small expansion joint is sufficient. You can take tremors.

The seismic isolation / vibration isolation system for a building above a railway track according to the present invention includes a foundation column connected to a foundation pile not provided with an underground beam and provided as a passage for a railway vehicle, and the foundation including a station facility. Base is built on the pillars, and arranged with the seismic isolation layer arranged the laminated rubber to soften the vertical stiffness disposed pillars of foundation of multilayer building is built over-track, the laminated rubber A viscoelastic damper disposed between the upper and lower beams of the seismic layer and incorporating a sliding bearing mechanism . Therefore, while improving seismic performance, the vibration isolation effect with respect to train vibration is enhanced by softening the vertical rigidity of the seismic isolation layer in which the laminated rubber is arranged. In addition, a viscoelastic damper is installed in the seismic isolation layer to suppress vibration amplification of the building above the seismic isolation layer.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a schematic view showing the principle of a basic seismic isolation system for a building over a track according to the present invention.
In this figure, 1 is a foundation pile provided in the ground, 2 is a foundation pillar connected to the foundation pile 1 and raised from the ground, and 3 is a space through which a train 4 passes. As described above, no underground beam can be provided between the foundation piles 1 provided in the ground. On such a foundation, for example, a multi-layered building 5 is constructed. Here, a seismic isolation layer in which the thick laminated rubber 6 is arranged at the base of the building 5 is provided in order to suppress the vibration accompanying the passage of the train. By arranging the laminated rubber 6 in this way, it is possible to soften the rigidity in the vertical direction and enhance the vibration isolation effect.

  FIG. 2 is a diagram showing the vibration isolation effect (experimental result) of such a laminated rubber, and shows the vibration conductivity from the foundation to the center of the building beam during train travel. In this figure, the horizontal axis represents the 1/3 octave band center frequency (Hz), the vertical axis represents the vibration acceleration level difference (dB), and ■ indicates the case where the seismic isolation layer (laminated rubber) according to the present invention is not provided ( (Non-Seismic Isolation), □ indicates the case where a seismic isolation layer (laminated rubber) according to the present invention is provided (seismic isolation). In particular, since the main component of railway vibration is 63 to 125 Hz, the seismic isolation effect in the frequency band is remarkable.

FIG. 3 is a schematic diagram of a seismic isolation system for a building over a track showing the first embodiment of the present invention.
In this figure, 11 is a foundation pile provided in the ground, 12 is a foundation pillar raised from the ground connected to the foundation pile 11, 13 is a space through which a train passes, and as described above, An underground beam cannot be provided between the foundation piles 11 provided on the ground. For example, a building 14 is constructed on such a basic structure. Here, the laminated rubber 15 is disposed at the base of the building 14 in order to suppress the vibration accompanying the passage of the train, and the viscoelastic damper 18 is provided at the center between the beam 16 and the beam 17 of the building 14. I try to arrange it.

By comprising in this way, especially when the space | interval of the foundation pile 11 becomes large, the vertical vibration of the upper and lower beams 16, 17 can be suppressed effectively.
FIG. 4 is a diagram showing a vibration isolation effect (experimental result) by the viscoelastic damper when the first embodiment is constructed, and shows a case where a viscoelastic damper is provided at the center of the beam of the building. In this figure, the horizontal axis represents 1/3 octave band center frequency (Hz), the vertical axis represents vibration acceleration level difference (dB), □ indicates that the viscoelastic damper according to the present invention is not provided, and ■ indicates the present invention. The case where the viscoelastic damper concerning this is provided is shown.

  The operational effects of the present invention can be clarified with reference to FIGS. That is, the vertical axis of FIG. 2 and FIG. 4 shows the vibration acceleration level difference between the foundation (pile head) and the central part of the base isolation layer upper beam, and positive means amplification and negative means attenuation. In FIG. 2, in a frequency band of 63 to 125 Hz where the vibration is the largest in general railway vibration, the seismic isolation with the laminated rubber (the present invention) has a greater attenuation than the non-seismic isolation without the laminated rubber. Thus, it is shown that the effect of vibration isolation is remarkable by carrying out the present invention. Here, the composition, structure and function of the laminated rubber used in the present invention will be described. By increasing the rubber thickness per layer and lowering the vertical rigidity as compared with ordinary laminated rubber, The natural frequency is lowered to reduce the vibration in the frequency band (approximately 63 to 125 Hz) where the railway vibration is dominant (see Non-Patent Document 2 above).

On the other hand, FIG. 4 shows the effect of the damper according to the present invention, in which the vibration amplification at the natural frequency where the vibration in the vertical direction is dominant is reduced.
The composition, structure and function of the viscoelastic damper of the present invention will be described. The viscoelastic material is a polymer material having viscosity and elasticity (here, a diene viscoelastic material is used). The viscoelastic damper has a structure in which a viscoelastic material and a metal are alternately laminated and bonded, and the vibrational energy is converted into thermal energy and absorbed by shear deformation of the viscoelastic material.

By using such a viscoelastic damper, it is possible to reduce vibration amplification in the vicinity of 10 Hz, which is a problem particularly in body vibration.
FIG. 5 is a schematic diagram of a seismic isolation system for a building over a track showing a second embodiment of the present invention.
In this embodiment, the viscoelastic damper 21 incorporates a sliding bearing 22.

FIG. 6 is a view showing an example of a sliding support mechanism according to the present invention.
In this figure, 31 is a beam, 32 is a sliding plate (SUS plate) disposed on the surface of the beam 31, 33 is a mounting plate, 34 is a sliding material mounting plate fixed to the mounting plate 33, and 35 is the sliding material. A sliding material 36 provided on the lower surface at the center of the mounting plate 34 is a gap between the sliding plate (SUS plate) 32 and the sliding material mounting plate 34.

A specific mechanism and function of the sliding bearing will be described with reference to the sliding bearing mechanism shown in FIG.
The sliding bearing is composed of a sliding material 35 and a sliding plate 32 (here, tetrafluoroethylene resin (PTFE) is used for the sliding material 35 and SUS (stainless steel plate) is used for the sliding plate 32), and the seismic isolation layer is horizontal during a large earthquake. When deformed in the direction, the sliding member 35 slides on the sliding plate 32. By installing the sliding bearing below or above the viscoelastic damper for vertical vibration (train vibration), the viscoelastic damper is prevented from being damaged by the horizontal deformation of the seismic isolation layer caused by a large earthquake. The elastic damper should not affect the horizontal behavior of the laminated rubber.

  When a building includes a station facility, there are many cases where a structure such as a pedestrian deck is adjacent to the building. A large-scale expansion seam considering deformation is required. On the other hand, in the case of an intermediate layer seismic isolation structure, the present invention is as described above in consideration that a small expansion joint is sufficient because the displacement below the base isolation layer is the same as the displacement of the adjacent structure. In addition, rational seismic isolation and seismic removal measures can be taken.

  In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

  The seismic isolation / vibration isolation system for buildings over railways according to the present invention can be used as a seismic isolation system for high-rise office buildings and apartments constructed over railways.

It is a schematic diagram which shows the principle of the seismic isolation system of the basic building above a track of this invention. It is a figure which shows the anti-vibration effect (experimental result) by the laminated rubber shown in FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the seismic isolation vibration isolation structure system of the building above a track which shows 1st Example of this invention. It is a figure which shows the anti-vibration effect (analysis result) by a viscoelastic damper at the time of constructing the Example shown in FIG. It is a schematic diagram of the seismic isolation system for a building over the track showing the second embodiment of the present invention. It is a figure which shows the example of the sliding bearing mechanism concerning this invention.

DESCRIPTION OF SYMBOLS 1,11 Foundation piles installed in the ground 2,12 Foundation pillars launched from the ground 3,13 Space through which the train passes 4 Trains 5 Multi-layered buildings 6,15 Laminated rubber 14 Buildings 16, 17, 31 Beams 18, 21 Viscoelastic damper 22 Sliding bearing 32 Sliding plate (SUS plate)
33 Mounting plate 34 Sliding material mounting plate 35 Sliding material 36 Clearance

Claims (2)

In the seismic isolation and vibration isolation structure system for buildings over the track where the track is laid at the bottom of the foundation of the building,
(A) a foundation pillar connected to a foundation pile not provided with underground beams to serve as a passage for a railway vehicle;
(B) Seismic isolation layer in which laminated rubber with softened vertical rigidity is arranged on the pillar of the foundation of a multi-layer building constructed on the foundation pillar including the station facility and constructed above the railway When,
(C) MenShinbo of the disposed between the upper and lower beams seismic isolation layer disposed laminated rubber, and over-track building, characterized in that it comprises a viscoelastic dampers sliding bearing mechanism is incorporated Vibration structure system.   The seismic isolation and vibration isolation structure system for buildings above the railway track according to claim 1, wherein the viscoelastic damper is disposed at a central portion of the isolation base layer.

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