A Successful Multilayer Sediment Capping Structure in Shallow Water

摘要

The paper presents aspects related to the design and construction of one of the world’s largest contaminated sediment capping projects in shallow water. Its location is the northwestern shoreline of Clark Island, which lies at the outflow of St. Francis Lake, along the St. Lawrence River,about 70 km West of Montreal (Quebec), Canada. The project posed major challenges due to the relatively shallow water environment where the fine sediments are subjected to the combined action of waves and currents, ice forces, as well as the low shear strength of contaminated sediments. The paper presents aspects related to the design of the engineered capping structure considering the various constraints related to the natural environment, innovative construction techniques used to install the submerged capping structure over a very low bearing capacity substrate, and the monitoring program implemented to follow the long-term behavior of the capping structure.