Abstract
The actual environmental wind conditions at ground level around a redevelopment area in Tokyo were observed by using 3-cup anemometers for a 3-year period from the start of construction work to completion of the high-rise buildings in the area. The 17 points in this area are assessed as to whether the wind conditions are acceptable or not for outdoor human activities, based on the three published criteria by S. Murakami et al., W. H. Melbourne, A. G. Davenport et al., The following concluding remarks are achieved. 1. According to Murakami et al.'s criteria, only three of the 17 points are unacceptable for outdoor restaurants because the exceedance probability of the daily maximum instantaneous wind velocity exceeds class 1. Class 1 means that a gust wind velocity of 10 m/s occurs on less than 37 days each year. Therefore, it is considered that the wind environment around the site remains acceptable for ordinary activities. 2. According to Melbourne's criteria, thirteen points are unacceptable for long exposure stationary activities. In addition, four points are unacceptable for short exposure stationary activities. In comparison to Murakami et al. 's criteria, his assessment results in a severe evaluation. 3. According to Davenport et al. 's criteria, using the hourly mean wind velocity, all 17 points are acceptable for long exposure activities. Therefore, Davenport et al. 's criteria provide the least severe evaluation among the three criteria. 4. Consequently, Murakami et al. 's criteria are confirmed to be midway between those of Melbourne and Davenport et al.. Also, judging from the wind environmental experiences obtained through our actual measurements around the site, we consider Murakami et al. 's criteria exactly correspond with the effect of wind on outdoor human activities. 5. If reference wind directions during the measurement of wind velocity at ground level are considered, large velocity ratios occur mostly due to the flow separation by the high-rise buildings, the flow through the narrow arcade, the downwash from the large buildings and the flow along the wide street. 6. The gust factor and turbulence intensity at ground level become 2.47 and 0.40 for U = 4 m/s, respectively.
