Author(s): A. Fortt; E. M. Schulson
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Keywords: No Keywords
Abstract: Coulombic shear faults characterize terminal failure when polycrystalline ice Ih is rapidly loaded under a moderate degree of confinement. Post-terminal deformation occurs through frictional sliding along the shear fault. To examine this latter stage of deformation, experiments were performed on freshwater S2 ice at –10o C. The ice was proportionally loaded biaxially across the column-shaped grains along a variety of allcompressive loading paths at four sliding velocities (8 × 10-1,8 × 10-2,8 × 10-3 and 8 × 10-4 mm/s. ). At each velocity Coulomb’s law describes the relationship between the shear strength of the fault and the normal stress across it, both at the onset of sliding and once sliding has progressed a few millimeters. The friction coefficient decreases with increasing velocity in a manner similar to that seen by Kennedy et al. (2000) in ice-onice experiments, but is higher by about a factor of two to four, depending upon the sliding velocity. The difference is attributed to surface roughness.
Year: 2004