Journal of Cold Regions Engineering

Constant strain‐rate and creep tests were conducted in uniaxial compression on saturated samples of six fine‐grained frozen soils at temperatures between $-5°$ and $-17°C\text{.}$ From the test results, a number of relationships were developed that do not include temperature as an explicit parameter. The constant strain‐rate test results yielded relationships between peak strength and yield strength and also between peak strength and residual strength. From the creep test results, relationships between secondary strain rate and time required to reach the secondary creep stage were developed. Furthermore, separate relationships between the relative creep load, defined as the creep stress‐to‐peak strength ratio, and the secondary strain rate, initial strain, and initial strain rate were developed. The creep behavior of a fine‐grained frozen soil at various temperatures is found to be similar under similar relative creep loads. The relationships presented in this paper may be valuable to the practicing engineer dealing with structures supported on different types of fine‐grained frozen soils.

Spectral analysis of surface waves (SASW) is a nondestructive test technique that can be used to determine profiles of surface‐wave velocity versus depth. In this work, the technique is used to determine the wave‐velocity profile at a selected site at several different days during the spring thaw periods of 1989 and 1990. The test technique uses standard procedures using two accelevometers connected to a spectral analyzer. Results from each test are processed using a desktop computer and programs developed specifically for analysis of the data. Over 200 tests are done on 20 different days, and results are summarized in the paper. Specific results indicate that the SASW technique has excellent potential for detecting time‐varying changes in soil properties. In particular, the results indicate that wave velocities at a given depth tend to start high (frozen soil), decrease to a low value (thawed wet soil), then increase (thawed dry soil) as the spring thaw period progresses. In addition, results show a good correlation between calculated thaw depth and thaw depth estimated from SASW techniques.