Item: Deformation analysis of the propagation saw test
Title: Deformation analysis of the propagation saw test
Proceedings: 2010 International Snow Science Workshop
Authors: Chris Borstad1* & David McClung2 1Department of Civil Engineering, University of British Columbia 2Department of Geography, University of British Columbia
Abstract: We present results of high speed photography films which show that the scale of slope normal deformation prior to unstable fracture in the propagation saw test (PST) is on the order of 1 mm. Tests were filmed at up to 1200 frames per second and the slab was seeded with tracing particles immediately above the weak layer. Particle tracking software measured the displacement, velocity and acceleration of each particle frame by frame during the test. The pixel resolution in close-up films was as high as 0.1 mm per pixel. The films consistently show that the majority of the slope normal deformation (collapse) of the weak layer occurs after the fracture has propagated within the weak layer. The films also show that the weak layer provides some residual support to the slab following the saw cut. We discuss several implications of these findings.
Keywords: propagation saw test, kootenay pass, british columbia