On the effect of using different penetrometers on CPTU test results on AMU-Morasko test site

Investigations were conducted at the test site of Adam Mickiewicz University in Poznań. The test site is located in the northern part of Poznań, within the marginal zone of the Poznań Phase of the Weichselian (Vistulian) glaciation. The subsoil consists of glacial till from the Vistulian glaciation, separated by fluvioglacial sandy sediments, and is covered with fine and medium sands with single grains of gravel. The quality of the geotechnical parameters of the tested subsoil was assessed for the constrained modulus and undrained shear strength. To determine these parameters, static penetrometers from two different manufacturers were used. The tests and the result analysis were performed in three stages. In the first stage, each penetrometer was used to investigate the homogeneity and diversification of the subsoil structure in the test sites. The subsoil structure diversification was examined by grouping statistically similar R_f coefficient values along the profile. In the second stage, the level of accuracy and precision in the assessment of the corrected cone resistance (q_t), friction on the friction sleeve (f_s), and pore pressure (u₂) were determined for individual penetrometers. In the final stage, differences between the constrained modulus and undrained shear strength were determined for both penetrometers. This analysis took into account the level of precision of the corrected cone resistance.