Correlation of standard penetration test and pressuremeter data: a case study from Istanbul, Turkey

In this study, correlations were obtained between standard penetration test (SPT) and pressuremeter data measured during an extensive geotechnical investigation conducted in Istanbul, Turkey. In this context, SPT blow counts (N) were correlated with pressuremeter modulus (EPMT) and limit pressure (pL). Empirical equations were proposed to estimate limit pressure from pressuremeter modulus, and EPMT/pL ratios were calculated and evaluated. An attempt was also made to correlate limit pressure to undrained shear strength (su) measured by unconfined compression strength test. Correlations were carried out for sandy and clayey soils separately. The quantity (total of 182) and quality of the data (use of same equipment and procedures during data acquisition in a well defined geological setting) mean the obtained correlations may be valuable for similar soils. It is anticipated that the correlations obtained may help designers in evaluating, comparing, interpreting or cross checking the soil parameters obtained from these two important in situ tests.