By Ian Hoyer, Ethan Green, Doug Chabot, Karl W. Birkeland
ABSTRACT: Knowing the Extended Column Test’s (ECT’s) effectiveness at different slab thicknesses is critically important for practitioners. To better understand the limitations of the ECT, we used the SnowPilot dataset to investigate the utility of ECTs for providing an index of crack initiation and propaga-tion on varying weak layer depths. The database currently contains 5013 ECTs conducted by 386, pri-marily professional, users worldwide between 2007 and 2016. The broad range of observers and snowpacks in the dataset allow us to examine variations in ECT results with changing weak layer depth across seasons and locations.