Velocidade de carregamento na estimativa de parâmetros geotécnicos

Strain rate effects and their influence in the prediction of geotechnical parameters is one of the main geotechnical engineering challenges. During seismic events or rapid loading, such as earthquakes, the soil exhibits a distinct behavior of what is observed during the structure’s life cycle, generating high excess pore pressures and high shear stresses mobilized by the viscous soil response. On the other side of the spectrum, low strain rates generate partial drainage during shear and, under this condition, the mobilized shear resistance does not correspond to the undrained shear strength. This paper discusses the behavior of soils when submitted wide range of strain rates, evaluating drainage conditions associated to the transition between drained response at low strain rates, to undrained viscous response in tests performed at high strain rates. Research efforts developed both in Brazil and Portugal are reviewed and their contribution to geotechnical design emphasized.