Alcatraz Dock Pile Assessment
Moffat & Nichols was hired to do a seismic retrofit of the main dock at Alcatraz. eTrac was contracted by Moffat & Nichol to do a mobile LIDAR scan of the piles supporting the pier and the seawall at Alcatraz Island. Besides having georeferenced data on the seawall and pile locations, eTrac analyzed the data and was able to categorize whether each pile was plumb or tilted. To accomplish these tasks, eTrac mounted a Riegl VZ400 terrestrial laser scanner to our survey vessel Ekko and mustered at Alcatraz Island at 5am to catch a -1ft tide to capture as much of the exposed seawall and piles possible.