Numerical investigations on pore-pressure response of suction anchors under cyclic tensile loadings
Author(s)
Shen, Kanmin
Wang, Lizhong
Guo, Zhen
Jeng, Dong-sheng
Griffith University Author(s)
Year published
2017
Metadata
Show full item recordAbstract
The suction anchor is an effective option for the anchor foundations of floating offshore wind turbines (FOWTs). During its long-term service, in addition to the static pretension load, the suction anchor is subjected to a series of cyclic loads that are caused by waves, currents and the continuous motions of the floating structure. Thus, excess pore-pressure will accumulate within the soil around the embedded anchor, and the anchor capacity tends to be reduced. In this paper, by introducing the oscillatory and residual mechanisms, a novel numerical model is proposed to predict the instantaneous variations and accumulations ...
View more >The suction anchor is an effective option for the anchor foundations of floating offshore wind turbines (FOWTs). During its long-term service, in addition to the static pretension load, the suction anchor is subjected to a series of cyclic loads that are caused by waves, currents and the continuous motions of the floating structure. Thus, excess pore-pressure will accumulate within the soil around the embedded anchor, and the anchor capacity tends to be reduced. In this paper, by introducing the oscillatory and residual mechanisms, a novel numerical model is proposed to predict the instantaneous variations and accumulations of excess pore-pressures around a suction anchor that is subjected to long-term vertical cyclic loads. The results indicate that excess pore-pressure builds up mainly in the shallow soil near the external anchor wall. As a consequence, the effective soil stress in this region decreases along with the interface friction between the external wall and the soil. Detailed parametric studies reveal that the accumulation of excess pore-pressure is obvious for a larger load magnitude and smaller load period. With a lower permeability, smaller shear modulus or smaller relative density of the seabed soil, the pore-pressure accumulation outside the anchor increases significantly.
View less >
View more >The suction anchor is an effective option for the anchor foundations of floating offshore wind turbines (FOWTs). During its long-term service, in addition to the static pretension load, the suction anchor is subjected to a series of cyclic loads that are caused by waves, currents and the continuous motions of the floating structure. Thus, excess pore-pressure will accumulate within the soil around the embedded anchor, and the anchor capacity tends to be reduced. In this paper, by introducing the oscillatory and residual mechanisms, a novel numerical model is proposed to predict the instantaneous variations and accumulations of excess pore-pressures around a suction anchor that is subjected to long-term vertical cyclic loads. The results indicate that excess pore-pressure builds up mainly in the shallow soil near the external anchor wall. As a consequence, the effective soil stress in this region decreases along with the interface friction between the external wall and the soil. Detailed parametric studies reveal that the accumulation of excess pore-pressure is obvious for a larger load magnitude and smaller load period. With a lower permeability, smaller shear modulus or smaller relative density of the seabed soil, the pore-pressure accumulation outside the anchor increases significantly.
View less >
Journal Title
Engineering Geology
Note
This publication has been entered into Griffith Research Online as an Advanced Online Version.
Subject
Civil engineering
Civil engineering not elsewhere classified
Geomatic engineering
Other engineering