Volume 30, N. 1, January-April 2007 | PDF(12 downloads)
An expedite method to predict the shear strength of unsaturated soils is proposed and tested against many soils of different origins and subjected to different test types. The method uses an empirical hyperbolic function that has been successfully used to fit experimental data. The parameters of this function are obtained considering effective shear strength parameters from saturated soil and from test results of air dried samples tested without the need of suction control. Air dried samples can be, alternatively, replaced by test results of samples tested at suction larger than the maximum suction expected in the problem under analysis. The good agreement between the estimate functions and the experimental data shown by both alternatives makes them promising and reliable to estimate unsaturated shear strength parameters for preliminary purposes. Key words: unsaturated soil, suction, shear strength, prediction, laboratory tests.