The most commonly used laboratory test in Geo-engineering research and in routine testing is the cylindrical compression test. This test is widely used to evaluate the stiffness and strength parameters of soils and other geologic materials. At the Minnesota Department of Transportation a MTS cyclic loading triaxial system is used for testing various types of subgrades and pavement materials under cyclic impulsive loading that corresponds to traffic conditions. Following some discussions between members of the Mn DOT Research Group and the University of Minnesota Soil Mechanics Group, it was decided that some improvements and modifications of the original triaxial set-up are feasible
The second part of this report is devoted to the presentation of the modifications and improvements of the triaxial apparatus that have been done in due course of the research period. In the third part the improved testing capabilities of the Mn DOT triaxial apparatus are demonstrated on the basis of one conventional and two unconventional experiments done on fat clay and on dry sand specimens, respectively.
