Abstract:

This paper presents the uniaxial compressive properties of landfast Antarctic sea ice in austral summer. The sea ice samples were collected during the 29th Chinese National Antarctic Research Expedition undertaken between November 2012 and April 2013. Specimens for mechanical testing were sampled using a Kovacs drill from 149-cm -thick ice. The sea ice comprised granular ice (15.4%), columnar ice (72.5%), and platelet ice (12.1%). For the mechanical tests, specimens 9 cm in diameter in cross section and 18 cm in length were cut from the columnar ice layer and then tested under different temperatures (–2, –4, –6, –8, and –10 °C) and strain rates ranging from 10^-6 to 10^-2 s^-1. Based on the experimental data, the uniaxial compressive strength of the sea ice was described as a function of porosity, and a quantitative expression of the uniaxial compressive strength, which comprehensively considers the influences of strain rate and temperature, was established. Moreover, the distribution of fragments from the uniaxial compression specimens was analyzed based on fractal theory. The results showed the fractal dimension of the fragment length increased steadily as the temperature and strain rate decreased. However, the fractal method could not be used to discuss the breaking degree of ice when creep-fatigue occurred at low strain rates.

Key words: Antarctic, sea ice, mechanics, uniaxial compressive strength, crushing regulation