Citation

Huang P, Wang X, Gu M. Disaster Adv. 2013; 6(5): 3-18.

Copyright

(Copyright © 2013, Shankar Gargh)

DOI

unavailable

PMID

unavailable

Abstract

In this paper, the wind data are measured from eight anemometers, which were mounted on a 40m tower at the height of 10, 20, 30 and 40 m respectively during typhoon Muifa on the east coast of Shanghai. Mean wind speed and direction, wind speed profiles, turbulence intensities, gust factors and peak factors are analyzed in detail. It is shown that the measured mean wind speed profile agrees well with power law and log law models under 40m height. Turbulence intensities and gust factors calculated from various observation heights first increase with mean wind speed and then almost keep invariant when the wind speed exceeds 10m/s and 12m/s respectively. The longitudinal and lateral gust factors increase with turbulence intensity and the empirical formulas, which can best express their relationship, are also obtained using least-square fitting technique. The profiles of turbulence intensity and gust factors and the variations of gust factors with gust averaging time are presented and related empirical fitting formulas are also obtained. In addition, peak factors for t = 3s are almost constant with the increase of mean wind speed and the averaged values for all 10 min data are 2.21, 2.12 and 2.00 respectively. The relationship between peak factor and gust averaging time on the basis of measured data was consistent with the research result of Durst.