Civil engineers perform analyses and make design recommendations for many types of structure including buildings, bridges, dams, highways, water treatment, and waste disposal facilities. A significant aspect of analysis and design is the proper understanding and evaluation of the stress history of the soils upon which these structures will be built. Current classroom teaching methods do not fully demonstrate how different stress histories affect the engineering properties of clay soils. This project implements a laboratory method that physically demonstrates the significance of the stress history of clay soils to undergraduate civil engineering students. A clay soil is mixed with enough water to produce a slurry. This material is then consolidated in four separate batch consolidometers to four different consolidation pressures. Thus, four quality samples are produced from the same slurry having the same classification and mineralogy but having different stress histories. The samples are then removed from the batch consolidometers and tested in standard l-D consolidation, unconfined compression, and triaxial test equipment to evaluate the consolidation and shear strength parameters. The data from these tests, along with the analyses of problems using these test results, demonstrate the significance of stress history on the engineering properties and performance of the clay soil.
