Investigation of the Erosion of In-Situ Capping Materials by Sea Waves

摘要

In-situ capping is designed to isolate and stabilize the underseacontaminated sediment. Though in-situ capping is being applied, longtermstability to keep the pollutants from being discharged needs to becarefully studied. Hydraulic model testing using a wave generator wascarried out to identify the erosion for required cap thickness to bemaintained, which are a critical factor to determine long-term stabilityof in-situ capping. 0.0750.425 mm sand was used as capping materialby applying 1:10 scale factor. The capping material was placed by aone-touch opening device in a wave channel before generating thewave, and then various wave conditions were imposed so as to monitorthe geometry change of cap which was formed by a mound of thecapping material. Consequently, with a 50-year frequency wave heightat a proposed site, very little erosion was monitored but causingexcessive erosion by increasing wave height.