Maximum Vertical Pullout Force of Torpedo Anchors in Cohesive Seabeds at Different Steady Pullout Velocities

Wang, C.; Wang, X.; Chen, X., and Yu, G., 2020. Maximum vertical pullout force of torpedo anchors in cohesive seabeds at different steady pullout velocities. Journal of Coastal Research, 36(5), 1068–1078. Coconut Creek (Florida), ISSN 0749-0208.A torpedo anchor is a new innovative mooring device. This device is simple to install, is inexpensive, and has good mooring performance. The maximum vertical pullout force of torpedo anchors is a crucial indicator for a mooring system. This paper reports the findings from large deformation numerical analysis and physical model tests of the torpedo anchor to provide insights of the effect of the pullout velocity on the pullout behavior of torpedo anchors in cohesive seabeds. The numerical model adopted the coupled Eulerian-Lagrangian method and was validated by the experimental data. The simulated soil flow around the torpedo anchor was also validated using the results of the half-anchor tests. A parametric study was performed to investigate the effect of pullout velocity on the maximum vertical pullout force of the torpedo anchor. Results showed that the maximum vertical pullout force corresponding to the actual pullout velocity and reference pullout velocity was 1.0 + 0.49log times the reference maximum vertical pullout force. A new formula based on earlier studies and present numerical simulated and experimental results was then developed; it can be used to readily predict the maximum vertical pullout force of torpedo anchors in cohesive seabeds. Finally, sensitivity analyses on the pullout velocity and reference undrained shear strength in the formula were also performed.