A cyclic CPT-based test for soil characterization: experimental and numerical study

The classical Cone Penetration Test (CPT) provides valuable information about soil strength, but does not yield directly deformability parameters. To address this limitation, a novel CPT-based testing device has been designed in the recent years to evaluate soil stiffness. The test involves a force-controlled cyclic loading applied to a penetrometer tip that moves independently from the driving shaft. In this paper, both physical experiments and a digital twin based on the Discrete Element Method (DEM) are used to evaluate the new testing method. The results demonstrate that: (1) a clearly defined pseudo-elastic behavior domain can be identified; (2) a pseudo-elastic deformation modulus can be derived; and (3) soil stiffness degradation with the stress loading level can be assessed by the test.