Shear modulus reduction and damping ratios curves joined with engineering geological units in Italy.

Numerical simulations of seismic site response require the characterization of the nonlinear behaviour of shallow subsoil. When extensive evaluations are of concern, as in the case of seismic microzonation studies, funding problems prevent from the systematic use of laboratory tests to provide detailed evaluations. For this purpose, 485 shear modulus reduction, G\G(γ) and damping ratio, D(γ) curves were collected from multiple literature sources available in Italy.