the hydrostatic pressure is, the greater the viscos-

proportional to temperature. It has been shown

ity coefficient, the lower the strain rate of ice, and

that the hydrostatic pressure being applied to ice

the higher the ice strength will be. For p > σmax the

decreases its melting temperature and thus its

strength under triaxial compression.

higher the hydrostatic pressure is, the smaller the

In the present report a different approach has

viscosity coefficient, the higher the strain rate,

been undertaken. The authors considered the ice

and the lower the ice strength will be. This is

strength as a function of two variables: the hydro-

confirmed well by test data (Jones 1982, Jones and

static pressure and temperature, i.e.,

Chew 1983).

Equation 2 can be rewritten in terms of maxi-

τ * = τ * (p, T ) ;

γ i = Const.

mum (peak) shear strength τ * = τ i and presented

˙

(1d)

i

i

i

as a product of two independent functions: a yield

At a constant strain rate the strength of ice in a

function τio(p) and a nondimensional function

multiaxial stress state is described by the para-

Φ (γ i ) of the constant strain rate

˙

bolic yield criterion with three parameters: the

τ * (p, γ i )  = τio (p) Φ (γ i ) .