Anchor Collision Analysis of Stone-filled Bags for Submarine Power Cable Protection using a Smoothed Particle Hydrodynamics Method

Abstract

Woo, J.; Kim, D., and Na, W.B., 2016. Anchor collision analysis of stone-filled bags for submarine power cable protection using a smoothed particle hydrodynamics method. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 720–724. Coconut Creek (Florida), ISSN 0749-0208.We present a method for the safety analysis of stone-filled bags used to protect submarine power cables from anchor collision, using a smoothed particle hydrodynamics (SPH) method capable of dealing with discrete rocks. For this purpose, stone bags were modelled using the SPH method. Using the terminal velocities of five anchors, we simulated the transient dynamic behavior that occurs when the anchors collide with the stone bags. The response was sensitive to the collision velocity, while the displacement responses were also sensitive to the shape of the anchor heads. Stockless anchors provided more sensitive responses, especially stresses, to the larger stone bag size. Our results indicated that the safety performance of the 3.0 m × 3.0 m × 3.0 m stone bag provided sufficient protection for all of the collision cases. It should be noted that the collision velocities corresponded to the maximum (terminal) velocity. For shallower water depths, resulting in anchor velocities less than the terminal velocity, the 1.5 m × 1.5 m × 1.5 m stone bag would also provide suitable protection against anchor collision.