The variability of soil is well known to affect the geotechnical performance of structures. As probabilistic design methods become more commonly used, the ability to measure the variability of soil becomes more important. However, by using only the point statistics of soil parameters in design (e.g. the mean and standard deviation), typically an over-estimation of failure probabilities occurs, leading to over-conservative designs. By looking at the spatial correlation (e.g. scales of fluctuation) a more accurate representation can be achieved. This paper presents a method to use vertical Cone Penetration Tests (CPTs) to detect both the vertical and horizontal scales of fluctuation. An extensive numerical and experimental investigation has been undertaken to understand how spatial variation can be estimated and to quantify the accuracy in that estimation. The impact of being able to quantify the uncertainty is illustrated via a simple slope stability example.
|Title of host publication||Cone Penetration Testing 2018|
|Subtitle of host publication||Proceedings of the 4th International Symposium on Cone Penetration Testing (CPT'18), 21-22 June, 2018, Delft, The Netherlands|
|Editors||Michael A. Hicks, Federico Pisano, Joek Peuchen|
|Place of Publication||London|
|Publication status||Published - 21 Jun 2018|
|Event||4th International Symposium on Cone Penetration testing - Aula Conference Centre, Delft, Netherlands|
Duration: 21 Jun 2018 → 22 Jun 2018
Conference number: 4
|Conference||4th International Symposium on Cone Penetration testing|
|Period||21/06/18 → 22/06/18|
|Other||CPT’18 will focus on the solution of geotechnical challenges using the cone penetration test (CPT), CPT add-on measurements and companion in-situ penetration tools (such as full flow and free fall penetrometers), with particular emphasis on practical experience and application of research findings. As CPTs play a major role in geo-engineering, CPT’18 will bring together the world’s experts who are working to improve the quality and reduce the difficulties involved. The symposium will be attended by academics, researchers, consultants, practitioners, hardware/software suppliers, certifiers and students. It will be a unique opportunity for meeting people and sharing high-level knowledge.|
de Gast, T., Vardon, P., & Hicks, M. (2018). Detection of soil variability using CPTs. In M. A. Hicks, F. Pisano, & J. Peuchen (Eds.), Cone Penetration Testing 2018: Proceedings of the 4th International Symposium on Cone Penetration Testing (CPT'18), 21-22 June, 2018, Delft, The Netherlands (pp. 289-294). CRC Press.