SNOWPACK TESTS

COMPRESSION TEST Tests for Initiation

Dimensions: 30cm upslope x 30cm wide. Isolate up to 120cm deep.

Term Description

Very Easy Fractures during cutting

Easy Fractures within 10 light taps using finger tips only

Moderate Fractures within 10 moderate taps from the elbow using finger tips

Hard Fractures within 10 firm taps from whole arm using palm or fist

No Fracture Does not fracture to CT10 to CT20 to CT30

EXTENDED COLUMN TEST Tests for Initiation and Propagation

30cm upslope x 90cm wide column, isolate 15 to 120cm deep.

Fracture propagates across the entire column during isolation

Fracture initiates and propagates across the entire column on the ## tap

Fracture initiates on the ## tap but does not propagate across the entire column. It either fractures across only part of the column (observed commonly) or it initiates but takes additional loading to propagate across the entire column (observed relatively rarely)

No fracture occurs during the test

FRACTURE CHARACTER RATINGS

A thin planar* crack suddenly crosses column in one loading step AND the block slides easily** on the weak layer.

Crack crosses the column with a single loading step and is associated with a noticeable collapse of the weak layer.

A crack of noticeable thickness (non-planar fractures often greater than 1cm), which usually crosses the column with a single loading step, followed by step-by-step compression of the layer with subsequent loading steps.

Resistant planar

BRK Break BRK