Stiffness of clayey silts of the Venetian quaternary basin from laboratory tests

The cohesive soils of the Venetian quaternary basin, mainly composed of silty-clays and clayey-silts, show a great non-homogeneity. This is due to the very complex past geological history which has brought about strong variations in soil particle-composition and in the overconsolidation ratio with the change in depth. The soil stiffness is influenced by this non-homogeneity, thus showing appreciable variations even in samples of a few centimeters in length. In order to characterize the stiffness of the cohesive soils an extensive in-situ and laboratory experimental investigation has recently been undertaken. Some preliminary results obtained at the University of Padova using a new triaxial stress/strain path apparatus equipped with a local strain measuring system are presented and discussed in this paper.