| OCR Text |
Show 7 the slope is always balanced ( even after failure) by the supporting base, only the tangential components are redistributed along the boundary; and second, the stresses created by a concentrated force are propagated through the snow according to an attenuation function which can be expressed as a power series in ^ , where * C is the distance to the point of application of the concentrated force. If r is relatively large, the term of the series with the smallest exponent, k. , is the dominating term and the other terms can be disregarded. Then, the increase in stress caused by a concentrated force is ( 14) ( 15) and according to the first hypothesis The stress change a t f 8 ^ becomes AZ = T ( T - 0 (, 6) and the total stress at f = ^ o is now 2 ( 17) The exponent, K is determined by the viscosity of the layer. When the viscosity is large, the forces are more concentrated, and therefore N is large; when the viscosity is small, the forces are distributed to a great distance and (< approaches 2 in the limit. This suggests the comparison rV\ = CO j K * °° * = 2 , K- l " 8) and further suggests as a first approximation N ( 19) |
