Correlation of SPT–CPT data from the United Arab Emirates

Abstract

The standard penetration test (SPT) is the most commonly used in situ test. However, cone penetration test (CPT) is becoming increasingly popular as an in situ test for site investigation and geotechnical design. Geotechnical engineers have gained considerable experience in design based on local SPT correlations. In the near future, the CPT design correlations will also be developed based on local experience and field observation. However, with the initial introduction of CPT data, there is a need for reliable SPT–CPT correlation so that CPT data can be used in the existence of SPT design correlations. Moreover, in those cases where only SPT results are available, engineers, who are more familiar with CPT interpretations, will translate the SPT blow counts (N-values) into CPT cone resistances (qc-values).Published SPT–CPT correlations have been reviewed and concluded that many of the correlations do not provide information on the statistical procedures used. The information on the geological variability of the test sites is also missing. It may be important if these parameters have an effect on these tests and correlation.This study proposes a method to select and proceed the data for SPT–CPT comparison. The traditional and statistical methods were used for the correlation of SPT–CPT test results from the United Arab Emirates (UAE). Traditional (arithmetic average) method gave a higher ratio than literature values. Statistical approaches gave almost similar results and less high results than arithmetic average method.The soils in this area are recent deposits, consisting mainly of sand with relatively high content of calcium carbonate. Although carbonitic soils are weaker than silicate soils, a high ratio may be explained by cementation, densification and shelly structure or gravel layers in the United Arab Emirates soils.