Dynamic characterization of fine-grained soils for the seismic microzonation of Central Italy

An accurate measurement of dynamic soil properties is essential to predict the nonlinear soil behavior under seismic loading conditions. This paper presents a database of cyclic and dynamic laboratory tests carried out after the 2016-2017 Central Italy Earthquake sequence, as part of the seismic microzonation studies in the area. The database consists of experimental results obtained on 79 samples investigated by means of dynamic resonant column tests, cyclic torsional shear tests or cyclic double specimen direct simple shear tests. The dynamic soil behavior is analyzed with reference to the small-strain wave velocity and damping ratio and to the modulus reduction and damping ratio curves. Experimental data are compared with the most widely used predictive models to underline the peculiarities of the investigated soils. Finally, a predictive model is calibrated to capture the nonlinear behavior of typical fine-grained soils from Central Italy.