Size effect and penetration rate of CPTU based on ABAQUS

The piezocone penetration test is one of the most widely used in-situ tests, but the research on the penetration mechanism has not been mature, which results in that empirical equations are always used to assess the behavior of soils with less accuracy. The ABAQUS is used to simulate the penetration process of the cone. The radius of cone is valued as 0.9, 1.8, 3.8 and 4.8 cm respectively to study the “size effect”. The rate of penetration is valued as 0.1, 1, 2, 3 and 4 cm/s to investigate its effect on the cone tip resistance. It is summarized that as the cone radius increases, the plastic zone area around the shaft and cone expands, the cone tip resistance decreases, and the maximum normalized horizontal affected distance decreases. Meanwhile, the steady-state cone resistance keeps constant with the increase of penetration rate without considering the excess pore pressure, but the steady-state condition is more easily reached.