Effects of fines content in numerical simulation of CPTu in silty sands

Abstract

The Cone Penetration Test (CPTu) does not measure soil properties directly; rather, it measures cone resistance, sleeve friction and pore water pressure, that correlated with laboratory test data, allow estimation of soil properties. These correlations work reasonably well in clean sand; however, they have been observed to provide poor estimation when fines are present. The aim of this work is to improve the estimation of fine contents in silty sands from CPTu measurements. Large deformation finite element analyses in ABAQUS implicit scheme with the "zipper technique" is used to simulate CPTu. The SANISAND model is used to capture the soil behaviour and account for fines content by altering the critical state line. Coupled consolidation analyses are performed to account for development of pore pressures during cone penetration. The influence of fines and drainage on the tip resistance and developed pore pressure is analysed. Existing field CPTu measurements would be back calculated using laboratory test data, to ascertain the accuracy of the developed framework. The results are analysed in tandem to improve the understanding of effect of fines content on CPTu response.