抄録
With the increasing population in the city and the sharp rise in land price in recent years, it is becoming more urgent to construct high-rise office and residential buildings in urban area. Therefore. the behavior of these buildings in a strong wind and the human response, as well as the environmental wind conditions around them are our serios concerns. We have recently measured the sway of the KEIO PLAZA Hotel building (height by smallest width=5.8) by use of the displacement meter newly developed by Nippon Electric Company with our cooperation, which consists of laser beam oscillator and gradient transmission detector, and succeeded in simultaneous measurement of wind velocity and direction as well as the building sway in a strong wind. It was found that the vibrational behavior of the building is made of long period component and short one. The former is considered due to the instantaneous wind pressure and to have irregular period because of the randomness of the wind "gust", and though the amplitude is relatively large, the acceleration is so small due to the long period of the gust that it is imperceptible to the occupants. On the other hand, the latter has a relatively small amplitude with the lst natural period of the building, that is, sinusoidal vibration of the fundamental mode, may be directly perceptible to them, if any, but in view of the references so far in hand, the maximum acceleration of the building due to the maximum instantaneous wind velocity in 50 year recurrence period is well below the perceptible threshold. Moreover, the maximum sway of the building in the same period is far below the allowable limit by various foreign codes.
