Analysis of hurricane wind loads on low-rise structures

Time series of pressure coefficients collected on the roof of a house by the Florida Coastal Monitoring Program during landfall of Hurricane Ivan on the Florida panhandle in 2004 are analyzed. Rather than using peak values, which could vary due to the stochastic nature of the data, a probabilistic analysis is performed to characterize extreme values of pressure coefficients and associated wind loads. It is shown that the pressure coefficient time series follows a three parameter Gamma distribution, while the peak pressure follows a two-parameter Gumbel distribution. The analysis yields a probability of non-exceedance of a given threshold of the pressure or load coefficients. For this specific house and specific storm, the 80 percentile load coefficient value of the probability of non-exceedance is -1.7. This is discussed in the context of ASCE 7 GCp values.