Compressive failure of ice during indentation by rock particles

The indentation of rock particles into ice is an important aspect of understanding subsea interactions involving ice features and gravelly soil. This paper investigates the indentation of rock particles into an ice specimen, where observations are made to study the effect of changes in indentation rate and the relative spacing from previously formed damage zones on resulting force and pressure trends. Experiments were conducted for three indentation rates: 10 mm/s, 0.5 mm/s, and 0.01 mm/s. Observations were also completed for three unique spacing distances (as multiples of mean rock diameter) between the rock particle and previous damage zones. These setpoint spacings were taken as 2D (26 mm), 5D (65 mm), and 7D (96 mm), where the diameter D was based on a mean rock diameter of 13 mm. Maximum observed forces and pressures exerted onto the ice by the rock particles are examined and compared based on changes in the noted test parameters. The behavior observed during these tests is also compared with results from prior ice indentation tests with steel spherical indenters. The research outlined in this paper will additionally inform future research on the nature of subsea interactions of icebergs with the ocean floor, and how this may affect potential risks related to subsea installations.