146. An Innovative Method to Evaluate Degree of Compaction of River Embankments

The paper illustrates an innovative method to evaluate the degree of compaction of both existing and new river embankments after their completion. A tip resistance target—profile is inferred from laboratory tests in a mini calibration chamber (CC) using a mini CPT (cone penetration test). The “laboratory” tip resistance (q_cLAB) is expressed as a function of the expected density and of the vertical—horizontal stress components. Such a dependence of q_cLAB is obtained carrying out a number of repeated tests in the CC at given density and different consolidation stresses. In situ stresses are inferred by combining DMT (Marchetti Dilatomer) results and an estimate of the vertical stress component. A comparison between the q_cLAB profile, from CC testing, and the q_c, as inferred from in situ CPT, gives the possibility of assessing the density of existing embankments, while, for new embankments, the method defines the expected in situ q_c for a given target density.