Probabilistic turbulence spectra of boundary-layer winds based on measurement at Jiangyin Bridge site

Abstract

The boundary-layer winds have distinct uncertainties in the spectra of turbulence, which makes the spectral characterization be a critical issue in wind engineering communities. Using the long-term monitored data at Jiangyin Bridge site, a turbulence spectral model is established in a probabilistic viewpoint, which considers the inherent uncertainties and offers an effective manner to describe the turbulent energy distribution. By adding an uncertain parameter in turbulence spectra, the modification of the probabilistic spectral models is realized, where the modified point model is superior in fitness accuracy of measured spectra than the modified blunt model. The uncertainties of turbulence spectra at the Jiangyin Bridge site can be described reasonably based on six correlated lognormally distributed random parameters, which are dependent on the mean wind speed. Comparisons are made with existing probabilistic models, and the results demonstrate the efficacy of the probabilistic point spectral model based on measured data at the Jiangyin bridge site. This model provides a basis for the probabilistic analysis of wind-induced vibrations of long-span bridges in a reliability viewpoint.