Integrated geogrid mattress armouring system for capping of contaminated dredge materials

Amand J. Silva
George E. Veyera


Disposal of highly toxic dredge material in offshore sites requires capping of the dredge mound to insure permanent isolation of the contaminants from the overlying waters. In areas of high energy hydrodynamic conditions, especially where there is potential for major storm events to occur, sediment caps may be eroded and the contaminated materials exposed. It is proposed that prefabricated geogrid mattresses be used as an armouring layer over the contaminated material to assure long-term stability and containment of the mound materials. An example design for a region of known intermittent wave activity is presented including fabrication, transport, placement, and monitoring of the armouring system.