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Response-controlled buildings and dampers considered (Buildings 4, 6, 9 from left).

Response-controlled buildings and dampers considered (Buildings 4, 6, 9 from left).

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Many tall buildings in Tokyo metropolitan area were strongly shaken during the Great East Japan Earthquake, March 11, 2011. Most of them are less than 40 years old, and have not experienced the shaking of such a strong level. The tall buildings less than 15 years old, constructed after the 1995 Kobe Earthquake, are typically response-controlled by...

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... 4 is a 21-story government office building ( Koyoma andKashima 2011, Kasai 2011b). It consists of a steel frame and 336 low yield point steel (wall) dampers and 284 viscous (wall) dampers (Fig. 7a). For seismic energy dissipation, the steel damper utilizes yielding of steel material, and viscous damper utilizes flow resistance of the polymer liquid with high viscosity ( Kasai et al. ...
Context 2
... energy from a small earthquake, and steel damper, the most economical among all types, would dissipate considerable amount of energy at a large quake, respectively. Building 6 is a 41-story office building ( Kasai et al. 2009Kasai et al. , 2011b. It consists of a frame using concrete-filled tube columns and steel beams, and 688 oil dampers (Fig. 7b). For energy dissipation, the damper utilizes flow resistance of oil with low viscosity. The valve placed at orifice is shaped to produce the force linearly proportional to velocity, but a relief mechanism to limit the force is provided, making the hysteresis to switch from an elliptical shape to a rectangle shape. Most likely, the ...
Context 3
... 9 is a 54-story office steel building constructed in 1979. It was retrofitted in 2009 ( Maseki et al. 2011) by attaching 288 oil dampers (Fig. 7c). 12 dampers per floor were attached to middle 24 stories of the building. The oil damper is similar to those used for Building 6, except that its relief mechanism is modified to reduce forces near peak responses. This aims to reduce the axial force of the column transmitting the damper force, and consequently uplift force of ...

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