The paper deals with the dynamic geotechnical characterization and the seismic response of the soil foundation for the construction of the Laboratory of Earthquake Engineering and Dynamic Analysis (L.E.D.A.), a reinforced concrete structure in the Enna area (Sicily, Italy).

The seismic response analysis requires the evaluation of the dynamic soil properties, such as the shear modulus G, the damping ratio D and the Poisson's ratio n. Dynamic soil properties can be derived by in situ measurement of the shear waves velocity V_S or estimating, by laboratory tests, the variation of the shear modulus G and damping ratio D as a function of shear strain g.

 In the paper a review of the main results of the in situ and laboratory investigations is described. In situ geotechnical tests, such as Down-Hole (DH) and MASW tests were carried out to evaluate the shear waves velocity profile (Vs). Typical laboratory tests, and Resonant Column, Cyclic Torsional Shear Test and Cyclic Triaxial Test, were carried out to estimate the soil foundation properties in static and dynamic conditions respectively.