Abstract
Offshore pipelines are typically laid on the seabed and lowered into the seabed (trenched) over large sections to provide protection from shipping and fishing activities, or to stabilise the pipeline from hydrodynamic loads. Accurate estimates of the resistance to upward pipeline movement of the overlying clayey trench-backfill are important for design and analytical purposes. The undrained shear strength (cu) of the upper layers of the seabed (particularly the initial 2 to 3 m below the mudline) is therefore a vital part of pipeline site investigations and is commonly found using the cone penetrometer (CPT). The limitations of standard CPTs may be overcome with the use of novel shaped penetrometers. The measured resistance can be easily used to calculate undrained shear strength using an unique bearing capacity or 'bar' factor. This paper describes the application of standard in situ cone penetrometer and T-bar tests from an ROV for the determination of undrained shear strength parameters for pipeline buried in deltaic soft clay. Comparisons with in situ plate bearing tests are also provided and the advantages of this novel form of in situ test are discussed.copyright
Original language | English |
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Pages (from-to) | 38-43 |
Number of pages | 6 |
Journal | Proceedings of the International Offshore and Polar Engineering Conference |
Publication status | Published - 1 Dec 2004 |
Externally published | Yes |
Event | The Fourteenth International Offshore and Polar Engineering Conference - ISOPE 2004 - Toulon, France Duration: 23 May 2004 → 28 May 2004 |