Example of cone penetration test on sandy ground

The figure shows an example of cone penetration test results for sand. Model grounds of dry Toyoura sand (silica sand) and of dry Shirasu (pumice sand) were tested. The diameter of the cone used was 11 mm and tests were carried out at 50 G.

Although small undulation which may be due to heterogeneity of the model was observed, tip resistance increased almost linearly with depth for Toyoura sand. While for Shirasu, slope of the tip resistance-depth curve dropped at around 7 cm penetration. Grain crashing and increased compressibility due to the low particle strength of Shirasu may be responsible for this.