Drainage assessment in silty sand deposits from variable rate CPTU

This study aims at providing a better understanding on the effect of penetration rate on piezocone measurements in a silty sand deposit located at a site of the Emilia-Romagna Region (Italy). In this site, CPTUs were carried out at non-standard penetration rates, ranging from 10 to 130 mm/s. The main idea is to identify the drainage conditions for such intermediate soils by varying the rate of penetration, taking into account that partially drained conditions may prevail during the test at the standard penetration rate (2 cm/s). Accordingly, the variation of qt and u2 with penetration rate has been examined, and it is shown the way in which the variation of the penetration rate affects the position of field data on the CPTU-classification chart recently developed by Schneider et al. (2008).