Dynamic properties of frozen soils. Part 3. Equipment for testing frozen soils using the resonant column method

The mechanical behavior of unfrozen soils and frozen ones under dynamic loads differs significantly. For example, according to the results of resonant column tests, the dynamic shear modulus of unfrozen soils can exceed that of the frozen ones by tens of times, the absorption coefficient can exceed by several times, the resonant frequency can reach hundreds of hertz, etc. This does not allow the use of conventional resonant columns for testing frozen soils. In this case, either the error of the results will be very high, or it will not be possible to complete the experiment as a whole. Therefore, for dynamic tests of frozen soils, it is necessary to develop specialized equipment. The article presents foreign experience in modifying a resonant column for testing frozen soils from the 1970–1980s to the present. Taking into account foreign developments and on the basis of the generalization indicators of the dynamic properties of frozen soils, recommendations are given for developing a domestic version of a resonant column.