On the reliability of SPT-N value as an indication of consistency of clayey soils

Abstract

Investigation of the shear strength properties and consistency distributions of the clayey alluviual soils of the Niksar basin located at the right bank of the Kelkit River and evaluation of the shear strength of the clays, and correlation of them with the consistency characteristics obtained from SPT-N values from Standard Penetration Tests is aimed in this study. Investigations of the study were programmed consisting Standard Penetration Tests in the field and index and shear strength tests in the laboratory. Undrained shear strength values obtained indicate the stiff consistency; classification due to the SPT blow counts in the same depths gives the same consistency properties, and the determination of the consistency of clayey soils by SPT-N value appears to be very reliable. The section constructed by using the SPT results from 24 boreholes 15 m in depth along the Niksar basin showed the widespread distribution of the clayey soils with stiff consistency. © 2004 ejge.