Field testing to determine the suitability of biosolids for embankment fill

Biosolids are defined as appropriately treated sewage sludge which consists of untreated organic slurry residue derived from wastewater treatment processes. The use of biosolids and other waste materials in a sustainable manner is currently being investigated in several countries around the world. This paper reports on results obtained from field investigations to assess the viability of using biosolids as stabilised fill for road embankments. Field tests were recently carried out on biosolids stockpiles at the Western Treatment Plant in Victoria, Australia. The field tests included field vane shear tests, standard penetration tests (SPT) and dynamic cone penetrometer (DCP) tests. Undisturbed tube samples and disturbed bulk samples were also collected for future laboratory testing. Geotechnical parameters from the field test were obtained and compared with the existing local road authority specification for fill material.