Date of Award
Master of Science
Civil, Construction, and Environmental Engineering
Cassandra J. Rutherford
Soft, flowable soils are problematic materials that are frequently encountered in geotechnical projects. These materials include soft marine clays, mine tailings, and dredged sludges. Soft marine clays which have a high liquid limit, have an in situ water content close to or above its liquid limit, and are sensitive are often encountered in marine settings in the design of offshore foundations, in hazard mitigation for submarine landslides, and in the installation of pipelines in the top few meters of seabed. Clays near the surface have the lowest strength due to no overlying self-weight and resultant low effective stress. These clays are often non-self-supporting - highly flowable - and thus are very difficult to test in a laboratory setting.
A previously developed internal split mold technique that allows a non-self-supporting material to be tested in triaxial shear compression with the application of a small confining pressure, and then consolidated and sheared as normal. Tests performed using this method have only been limited to mine tailings, sand, and dredged sludge, and has not been used to consolidate and test soft clays.
The objectives of this research study were to further develop the internal split mold technique and examine how it can be applied to soft clays at very low effective stresses (20 - 30 kPa) corresponding to the upper several meters of seabed. Three Consolidated Undrained Isotropic Compression (CUIC) triaxial shear tests were conducted on pulverized Kaolin (PL = 41%, LL = 62%) mixed to a slurry at 100% water content. The stress-strain data were then analyzed and compared to published strength behavior of Kaolin clay.
Maher, Adam, "Development of a split mold for internal consolidated undrained isotropic compression (CUIC) testing of low effective-stress soils from slurry" (2018). Graduate Theses and Dissertations. 16404.