Discussion of 'Equivalent Static Wind Loads on Buildings: New Model' by Xinzhong Chen and Ahsan Kareem

摘要

The authors proposed a rigorous model for evaluating equivalent static wind loading (ESWL) on tall buildings as a linear combination of mean, background, and resonant components. In this model, the mean and resonant ESWL components are essentially the same as those reported in such literature as Zhou et al. (2000) and Zhou and Kareem (2001). However, the treatment of background ESWL (BESWL) introduced some improvements. The BESWL in the conventional displacement-based gust loading factor (GLF) model (Davenport 1967; Zhou et al. 1999), as used in most current codes and standards, and that in a newly developed bending-moment-based GLF model (Zhou and Kareem 2001) produce accurate estimates for limited wind load effects only, such as the first model displacement or base bending moment, while providing approximate estimates for others. Unlike those "approximate" models, the proposed BESWL will induces the exact wind load effect of interest. In contrast with a previous "accurate" ESWL model (Holmes 2002a,b), which also involves a linear combination of wind load components while the distribution of its BESWL varies for different wind effects, the proposed model uses a unique background loading pattern, the gust loading envelope, which offers some convenience for the purpose of design application.