Gel barrier - a biodegradable flexible underwater material to limit sedimentation or prevent scour
Type:
Presented during:
CEDA Dredging Days 2026
Authors:
L. de Wit, L. Jaksic, J. Hanssen and S. Gamberoni
Abstract
Maintenance dredging efforts in ports are associated with high yearly costs and emissions. To reduce these maintenance costs and emissions, gel barriers, biodegradable underwater dams, could reduce the spreading of sediments into certain port areas. Gel barriers are a combination of dredged material (i.e., local mud and sand) and a biological flocculating agent. The basic idea is that this gel is sufficiently solid to function as an underwater dam and keep the sediments out and, at the same time, sufficiently liquid for a safe passage of ships. We foresee four applications of the gel barrier in marine systems. 1) A gel barrier can be placed in a port entrance to limit sedimentation in the port behind the barrier. 2) A gel barrier can be used to limit sedimentation at berthing places which are difficult to dredge. 3) Gel can enhance flocculation in silt traps to increase storage capacity and prevent resuspension of sediment from these traps. 4) A different potential application is to use the gel in a thin layer on the bed as a temporary scour protection which can be easily penetrated by (mono)piles during installation. We present different gel recipes, rheological and erosion tests to determine the strength of the gel, and CFD simulations of a ship passage over a gel barrier. The paper will end with an outlook of the potential and remaining challenges for this innovation.
Keywords: