Effects of partial drainage on the assessment of the soil behaviour type using the CPT

This paper presents the results from a series of CPTs performed at various penetration rates in kaolin, two kaolin-sand mixtures and fine silica sand. The CPTs were conducted in laboratory pressure chambers at penetration velocities varying from 0.0002 to 3 mm/s. The measured dependence of cone end resistance (q_t ), sleeve friction (f_s ) and pore pressure (u₂ ) on penetration rate is used to examine implications for the assessment of soil behavior type from CPT parameters. Element tests using triaxial and direct interfaces tests are used to assist interpretation of the test results.