Investigation on the nondeterministic dynamic structural response of tall buildings

Resumo

Based on the last few decades, the Brazilian cities have presented a relevant increasing when the design
and construction of tall and slender buildings is considered. It must be emphasized that this architectural trend
produced very flexible structures, with low natural frequency values and more susceptible to excessive vibrations
problems, especially when subjected to wind dynamic loads. Having these ideas in mind, this investigation aims
the study of tall buildings non deterministic dynamic structural response, considering the soil-structure interaction
effect. This way, the developed analysis methodology considers the wind pressure coefficients on the building’s
facade determined based on the use of CFD (Computational Fluid Dynamics) techniques that nowadays represents
an increasingly important role in high-rise buildings projects, utilised as a sophisticated analysis method to predict
the airflow on the building’s structural system. This way, the nondeterministic dynamic structural behaviour of a
40-storey reinforced concrete building, 140 m high and floor dimensions of 9 m by 29.05 m was investigated. The
building numerical model was developed to obtain a realistic representation of the structure, based on the Finite
Element Method (MEF), using the ANSYS program. It must be emphasized that the results obtained throughout
this research work, considering the wind pressure coefficients calculated based on CFD techniques and those
determined by the Brazilian design standard NBR 6123 have indicated important quantitative differences, when
the dynamic structural response (displacements and peak accelerations) and the building human comfort were
investigated.