Use of SDMT results for earthquake resistant design: examples of application in silty-clayey sites

This paper comments on the use of results of seismic dilatometer tests (SDMT) for the site characterization aimed at the definition of the seismic action on constructions, a key element in earthquake resistant design. Examples of application are presented with particular reference to silty-clayey sites. The following issues are addressed: (1) Use of the "surrogate" parameter Cu (undrained shear strength), in place of the "primary" parameter Vs (shear wave velocity), for the identification of ground types required to determine the seismic action according to the Eurocode 8. (2) Experimental interrelationship between small strain and working strain stiffness using SDMT. (3) Evaluation of Vs from mechanical DMT data. (3) Use of SDMT results for deriving in situ G-γ decay curves.