Obtaining Representative Stiffness Degradation Parameters from the Resonant Column

Wen, K., Buckley, R. and Byrne, B. (2023) Obtaining Representative Stiffness Degradation Parameters from the Resonant Column. In: 9th International SUT OSIG Conference “Innovative Geotechnologies for Energy Transition”, London, UK, 12-14 Sep 2023,

Abstract

Offshore wind turbines (OWT) are emerging as a crucial component of renewable energy in Europe, reinforcing the importance of efficient and reliable foundation designs to ensure long-term economic viability. The determination small strain stiffness parameters of soil, including shear stiffness (G0), shear degradation (G/G0), linear ( tl) and volumetric threshold shear strain ( tv) using the Resonant Column Apparatus (RCA) is now routine in most offshore site investigations. Accurate measurements of such properties are essential for dynamic loading conditions such as those experienced by OWT. This paper presents the results of RCA tests on a naturally occurring sand from a site representative of offshore conditions. A key observation in this study was that the measured stiffness degradation within the elastic region of soil ranged from G/G0 = 84%-96% corresponding to tv values of 0.1-7.7×10-3%, beyond which non-elastic behaviour was observed. The RCA has capabilities of inducing strains up to 10-2%, at least a magnitude of order higher than tv. The results demonstrate the need for small strain checks to be incorporated in routine RCA testing to establish the true limit of elastic soil behaviour. The results haveimplications for the use of the RCA in the calibration of degradation threshold strains such as, 0.7, the shear strain where G/G0=70%. A combination of test methods is advised for accurate determination of this value.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Buckley, Dr Roisin
• Authors: Wen, K., Buckley, R., and Byrne, B.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment

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