An experimental study on the mechanical behavior of a depth hoar layer under shear stress

Abstract

Simple shear experiments were carried out to understand the mechanical behavior of a depth hoar layer at various shear strain rates of 10(-5) s(-1) to 10(-3) s(-1) at temperature of -6 C. Ductile deformation took place in the layer at the shear strain rate lower than 8 x 10(-5) s(-1) and typical brittle fracture took place at the shear strain rate higher than 2 x 10(-4) s(-1). The critical shear strain rate for the ductile-brittle transition was considered between these values. Shear strength increased with increasing shear strain rate within the ductile deformation region and took the peak value at the critical shear strain rate for the ductile-brittle transition. Experimental result indicated that a natural slab avalanche does not occur in the absence of super-weak zone in the weak layer dealt in this study.