Dynamic characteristics of hydraulic fills from cyclic triaxial testing

Hydraulic fills pose great threat to significant liquefaction-induced damage as observed at the port of Wellington in the Kaikōura earthquake. Despite these hydraulic reclamation fills (comprised of sand, silt, clay, and shell mixtures) being prone to liquefaction, understanding their dynamic characteristics is difficult as it pertains to effects of fines and plasticity, which are difficult to capture through routine site investigations. This study assesses the dynamic characteristics of the hydraulic fills through Dames and Moore and Gel-Push sampling, which are mainly applicable to sands and fines. The samples were extracted and transported to the laboratory with careful procedures to minimize disturbance to its fabric. Specimens were tested under monotonic and cyclic loading using a state-of-the-art cyclic triaxial device, complemented by index and bender element testing.