CYCLIC AND MONOTONIC STRESS-STRAIN CHARACTERISTICS OF WEATHERED ROCK

The results of a series of monotonic and cyclic triaxial tests on undisturbed and recon-stituted specimens of weathered Keuper Marl, a calcareous mudstone formed mainly from clay minerals, are presented. Specimens with different stress-histories were subjected to monotonic and strain-controlled cyclic loading in the low frequency range, utilising an automated triaxial system specially developed for this purpose. Results are presented which relate the changes in engineering properties of the tested ma-terial, such as shear strength and stiffness, to cyclic strain amplitude, number of loading cycles and previous stress-history of the weathered rock. Correlations between the monotonic and dynamic behaviour of specimens are presented