|摘要: ||建築物在受風擾動下，除安全性上受關注，其使用人員的舒適度在結構設計裡亦是一個重要的議題。對於建築物受風影響造成的振動，其舒適度規範的制定長久以來一直備受爭議，除了身體因素之外，還包括心理、外在因素等眾多影響。台灣目前風力規範訂定之舒適度標準為 5 mm/sec² 加速度，對應之回歸週期為半年。|
Under wind disturbance, the comfort of occupants in buildings is an important issue in the structural design aside from safety consideration. The human comfort criterion for wind-induced motion has been a long-time controversial issue because many factors, either physiological or psychological, can considerably differentiate the outcome. Recently, a constant criterion of 5 cm/sec2 for a half-year return period was regulated in Taiwan building wind code.
In an attempt to build up the local data base in preparation for improving the building wind code in the future, this research aims to conduct surveys to investigate the comfort criteria by using a motion simulator in the wind engineering research center, Tamkang University. A methodology and feasible procedure to determine the comfort threshold and the return period were proposed in this study. Two types of surveys by using harmonic motion and random motion, respectively, were performed to obtain the comfort thresholds for 2%, 10% and 50% of people objecting and their corresponding return periods.
The survey results indicate that
(1) The comfort thresholds are frequency-dependent in 0.1~1.08 Hz.
(2) Under a harmonic motion, people with body orientation in fore-aft direction are more sensitive to vibration than in side-to-side direction. But this observation does not apply to random motion situation.
(3) Under a harmonic motion, the comfort (acceleration) threshold decreases as the vibration frequency increases.
(4) Under a random motion, the comfort (acceleration) threshold increases as the vibration frequency increases.
(5) Under a random motion, the peak motion effect plays an more important role in comfort when the vibration frequency is lower, while the average motion effect (root-mean-square) is more emphasized in terms of feeling if the vibration frequency is higher.
Unfortunately, it is found that, following the methodology proposed, the return period obtained does not reasonably increase with percentage of people objecting. It might be due to the assumption of Poisson distribution in regard to the vibration, which is worth further investigating in the future studies.