AERODYNAMICS OF LOW-RISE BUILDINGS AND CODIFICATION

Translating the results obtained in a wind tunnel experiment to load specifications for a Code of Practice needs an intensive cooperation between aerodynamicists and structural engineers. Generally, a pure aerodynamic analysis of only the wind action could not be a sufficient basis for a load specification. Requiring both, a safe and economic design, a study of the wind effects becomes necessary taking a close look to the design. In this context, the coincidence of extreme pressures becomes most important. The paper discusses some typical codes of practice and their models of coincident pressures. The quality of these codes is reviewed by comparing their design to results obtained in a wind tunnel experiment. Most alarming, one has to state for many design-practical cases a considerable underestimation of the design-decisive effects. The new Eurocode removes this defect by introducing an alternative load distribution presenting a positive pressure on the roof.