For cost effective construction, it is often necessary to optimize the use of on-site materials. At the Omai Gold Mine in Guyana, South America, tropical residual soils are used for construction of the tailings storage facility. At present, the geotechnical characteristics of residual soils have not been investigated or reported to the extent that transported soils have been. Geotechnical design and construction with these tropical residual soils can present unique challenges and problems. This case record outlines the investigation and construction procedures for the facility and provides a sample of the typical geotechnical engineering properties exhibited by the native tropical soils. In addition, data on observed behaviour and experience obtained handling and placing the materials as well as the performance of the structures during construction are provided.Key words: tropical residual soils, geotechnical design, tailings storage facility.
