For these data, the test technique employed was that

Within the test ranges the relative effects are small

93

given by Stevens . Complex moduli may be used as

except for partially saturated clay. However, the effect of

equivalent to elastic moduli when damping is normally

stress and/or frequency on the shear modulus could be

small.

significant for stresses and/or frequencies outside these

(h) As shown in figure 4-56, complex

test ranges.

Therefore, these relationships are

sufficiently important to warrant consideration when

Young's modulus of 100 percent ice-saturated, non-

choosing a modulus for design.

plastic frozen soils increases sharply as the ice

(k) Smith91 has published data on

volume/soil volume ratio decreases.

As the ratio

properties of snow and ice under vibrating loads.

increases the modulus approaches that of ice. The

(I) The data presented in this manual

relationship shown does not appear to apply for plastic

soils.

and in the reference publications serve only as a guide

(i) Figures 4-57 and 4-58 show the

and it will be necessary in most problem cases to carry

relationships of complex shear and Young's moduli to

out a test program covering the range of soil conditions,

percent ice saturation. The moduli decrease rapidly with

test freq

decrease in percent saturation, obviously approaching

the moduli in a non-frozen state.

(j) Figures 4-59 and 4-60 show the relationship

between shear modulus, stress level, and frequency.

U. S. Army Corps of Engineers

Figure 4-56. Complex dynamic Young's modulus vs. volume ice/volume soil ratio for frozen saturated, non-plastic soils.