Comparison of geotechnical uncertainties linked to different soil characterization methods

ABSTRACT

One of the essential inputs in settlement prediction models is the soil modulus, which may be obtained from laboratory tests or estimated from in situ measurements. The total uncertainty in predicting the confined modulus of a sandy soil is quantified with data from side-by-side in situ testing using the standard penetration test, the static cone penetration test, the light dynamic probing and the laboratory oedometer test. To estimate transformation errors, correlations are proposed between in situ and laboratory data. The results indicate that similar magnitudes of total uncertainties are associated with the in situ methods, which are approximately twice as high as those from the direct oedometer method. The quantified uncertainties are an important input for reliability-based designs of foundations under similar soil conditions.

KEYWORDS:

• Settlement prediction
• geotechnical uncertainty
• in situ tests comparison
• oedometer test
• soil modulus
• reliability-based design

Acknowledgments

The authors wish to acknowledge the support of Sida (Swedish International development Cooperation Agency) through the project Continuous Penetration Test as Alternative to Intensive Borehole Investigation under the Rural and Urban Infrastructure Development Program (Tanzania), The Swedish Research Council Formas through the project TRUST – Transparent Underground Structure and the research programme BIG (Better Interaction in Geotechnics). We also thank the anonymous reviewer for the constructive comments.

Disclosure statement

No potential conflict of interest was reported by the author(s).