Immersed Structures Touchdown on a Gravel Bed Covered with Mud Layer: Application of CFD to Determine Mud Clearance and Gravel Stability
Type:
Presented during:
WODCON XXIII - Dredging is changing - The Practice. The Science. The Business.
Authors:
B. Decrop, E. Fonias, F. Kyrousi, T. Wolf, K. de Wit
Abstract
"The process of installation of submerged structures in the presence of sediments is a complex procedure. The lowering speed of those structures can jeopardize the stability of the gravel bed used for providing uniform bed conditions for the structure placement. Furthermore, a layer of deposited sediments on top of the gravel bed can pose severe risks with respect to installation tolerances and project delays. In the present paper, a numerical model is presented, capable of simulating the last stage of installation of structures on a porous gravel bed, taking into account the presence of a mud layer. The model uses a dynamic mesh to simulate the motion of structures within the numerical domain. The model can determine the uplift forces exerted by the mud layer on the structure, along with the motion of the mud layer during the installation procedure. This method provides insights in the risk for (1) a remaining layer of mud between structure and gravel bed and (2) damage to the gravel bed due to lowering-induced flows."
Keywords: structures installation, porous media, fluid mud