Breakout force required for jack-up spudcan extraction from sand-over-clay seabeds
| Autor: | Fauzan Sahdi, Mark Cassidy, Pan Hu, Sam Stanier |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
021110 strategic
defence & security studies Centrifuge Breakout Consolidation (soil) 0211 other engineering and technologies 02 engineering and technology Geotechnical Engineering and Engineering Geology Penetrometer law.invention law Soil water Geotechnical engineering Submarine pipeline Seabed Geology 021101 geological & geomatics engineering Civil and Structural Engineering Spudcan |
| Zdroj: | Soils and Foundations. 60:413-424 |
| ISSN: | 0038-0806 |
| Popis: | Spudcan retrieval from clay soils remains a major concern offshore as the extraction force required to overcome suction and soil resistance often exceeds the pulling capacity available on the mobile jack-up, causing extensive delays. Although methods to calculate extraction resistance have been recently suggested for seabeds of pure clay, to date there is no guidance available for the commonly encountered sand-over-clays. Based on failure mechanisms observed in half-spudcan visualisation tests, and calibrated against an extensive geotechnical centrifuge database of precisely measured extractions, this paper presents a method for calculating the force required to extract the spudcan foundations of mobile jack-up platforms after they have penetrated through a sand layer into underlying clay. Complexities, such as the strength degradation and strength recovery of the underlying clay soil, that occurs during spudcan installation and jack-up operations, are accounted for. Validation of the proposed method is demonstrated by retrospective prediction of the centrifuge testing database. The method outlined will allow operators of jack-up platforms to assess the extraction force prior to jack-up installation and to plan operational scenarios based on seabed conditions. |
| Databáze: | OpenAIRE |
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