Analysis of cone penetration testing on dilatant cemented sand by bearing capacity and cavity expansion models

Semi-empirical interpretation methods incorporating theoretical models have been used to analyze in situ cone penetration test results. These interpretation methods can be further improved by allowing a more realistic simulation of soil dilational behavior around the cone penetrometer. In the present work, an attempt is made to assess two bearing capacity and two cavity expansion theoretical models with distinct soil behavior models in interpreting the cone penetration test results. Calibration chamber tests conducted on dilatant cemented sands provided the measured cone test parameters. Comparisons are first made between bearing capacity model predictions and cone test results. Bearing capacity model by Durgunoglu and Mitchell (D & M) [6] has predicted tip resistances, which are different from measured tip resistances only at higher confining pressures and high relative densities. This can be attributed to the dilational behavior effects, which are not considered in the original formulation. Janbu and Senneset (J & S) [7] model predictions using a plastification angle parameter have matched well with the measured tip resistances. Spherical cavity expansion models formulated by Carter et al [10] and Yu and Houlsby [11] are used to compute the limiting pressures of calibration chamber tested specimens. Ratios between measured cone tip resistances and predicted limiting pressures are determined and they varied between 3 and 6. Lack of realistic dilational behavior in the strain-softening zone of the stress-strain response might have resulted in high limiting pressures and low ratios. A field study conducted on a natural cemented loess deposit near Natchez, Mississippi, has reconfirmed the above findings on both theories' interpretations.