Wind action on regular and irregular tall buildings: Higher order moment statistical analysis by HFFB and SMPSS measurements

In this paper the results of experimental tests in a boundary layer wind tunnel aimed at direct comparison of the two main methods used to estimate the wind loads acting on tall buildings are presented. The tests were performed on two different models of tall buildings: a regular one with a prismatic shape; an irregular one whose external shape was inspired by that of Bank of China Tower in Hong Kong. The two models have the same square footprint and height. The two methods used to measure the wind effects were: the high frequency force balance, which allows to directly measure the global base reactions (two forces in the plane of the base, the two overturning moments and the torsional moment around the vertical axis); the synchronous multi-pressure sensing system, which measures the pressure in several points on the surface of the model, and allows, by means of numerical integration, to estimate both the floor loads and the base reactions. In order to perform a comparison between the results obtained by the high frequency force balance and synchronous multi-pressure sensing system a statistical analysis of the results was carried out; in particular, higher order moments were investigated. Moreover the spectra and the correlation structure of the loads were studied.