Abstract
Geotechnical design of offshore shallow foundations is generally based on a cyclically degraded shear strength, typically determined from a shear strain or pore pressure accumulation procedure based on contour diagrams derived from laboratory tests. The procedure was initially developed for gravity-based structures and is now used for a wider range of offshore applications including shallow foundations for subsea structures that are subjected to different cyclic loading regimes. The applicability of the traditional equivalent cyclic shear strength approach based on the accumulation procedure is investigated for a specific type of subsea structure, the Zero-Radius Bend (ZRB) trigger. A series of centrifuge tests have been performed on a shallow skirted foundation on normally consolidated kaolin clay under a range of horizontal cyclic load sequences typical of those applied to foundations of ZRB triggers during pipe-laying. The observed performance from the centrifuge tests is compared with predictions of foundation performance using the traditional strain accumulation procedure. It is shown that the traditional procedure over predicts strength degradation at the end of the particular cyclic load sequences. The findings indicate that a performance-based approach may be more appropriate for the geotechnical design of these foundations and other foundations with a high tolerance to displacement.
| Original language | English |
|---|---|
| Article number | 106062 |
| Journal | Ocean Engineering |
| Volume | 186 |
| DOIs | |
| Publication status | Published - 15 Aug 2019 |
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Applicability of the strain accumulation procedure for the geotechnical foundation design of zero-radius bend triggers. / Zografou, Dimitra; Banimahd, Meysam; Gourvenec, Susan; O'Loughlin, Conleth.
In: Ocean Engineering, Vol. 186, 106062, 15.08.2019.Research output: Contribution to journal › Article
TY - JOUR
T1 - Applicability of the strain accumulation procedure for the geotechnical foundation design of zero-radius bend triggers
AU - Zografou, Dimitra
AU - Banimahd, Meysam
AU - Gourvenec, Susan
AU - O'Loughlin, Conleth
PY - 2019/8/15
Y1 - 2019/8/15
N2 - Geotechnical design of offshore shallow foundations is generally based on a cyclically degraded shear strength, typically determined from a shear strain or pore pressure accumulation procedure based on contour diagrams derived from laboratory tests. The procedure was initially developed for gravity-based structures and is now used for a wider range of offshore applications including shallow foundations for subsea structures that are subjected to different cyclic loading regimes. The applicability of the traditional equivalent cyclic shear strength approach based on the accumulation procedure is investigated for a specific type of subsea structure, the Zero-Radius Bend (ZRB) trigger. A series of centrifuge tests have been performed on a shallow skirted foundation on normally consolidated kaolin clay under a range of horizontal cyclic load sequences typical of those applied to foundations of ZRB triggers during pipe-laying. The observed performance from the centrifuge tests is compared with predictions of foundation performance using the traditional strain accumulation procedure. It is shown that the traditional procedure over predicts strength degradation at the end of the particular cyclic load sequences. The findings indicate that a performance-based approach may be more appropriate for the geotechnical design of these foundations and other foundations with a high tolerance to displacement.
AB - Geotechnical design of offshore shallow foundations is generally based on a cyclically degraded shear strength, typically determined from a shear strain or pore pressure accumulation procedure based on contour diagrams derived from laboratory tests. The procedure was initially developed for gravity-based structures and is now used for a wider range of offshore applications including shallow foundations for subsea structures that are subjected to different cyclic loading regimes. The applicability of the traditional equivalent cyclic shear strength approach based on the accumulation procedure is investigated for a specific type of subsea structure, the Zero-Radius Bend (ZRB) trigger. A series of centrifuge tests have been performed on a shallow skirted foundation on normally consolidated kaolin clay under a range of horizontal cyclic load sequences typical of those applied to foundations of ZRB triggers during pipe-laying. The observed performance from the centrifuge tests is compared with predictions of foundation performance using the traditional strain accumulation procedure. It is shown that the traditional procedure over predicts strength degradation at the end of the particular cyclic load sequences. The findings indicate that a performance-based approach may be more appropriate for the geotechnical design of these foundations and other foundations with a high tolerance to displacement.
KW - Centrifuge modelling
KW - Cyclic loading
KW - Shallow foundations
UR - http://www.scopus.com/inward/record.url?scp=85067624211&partnerID=8YFLogxK
U2 - 10.1016/j.oceaneng.2019.05.044
DO - 10.1016/j.oceaneng.2019.05.044
M3 - Article
VL - 186
JO - Ocean Engineering
JF - Ocean Engineering
SN - 0029-8018
M1 - 106062
ER -