Engineering Characteristics Analysis of Deepwater Well-site Marine Clay in South China Sea

Multiple methods are employed to explore the deepwater marine clay engineering characteristics with high plasticity at one well site in south China sea. Based on the CRS and ODE tests, the differences of stress history are quantified. Test results indicate that the SHANSEP（Stress History and Normalized Soil Engineering Properties） method is suitable for the objective evaluation of offshore cohesive soils from the South China Sea, by which the strength profile along depth is described. The strength anisotropy is quantified by Ck0 UC/E tests and the unconsolidated undrained shear strength is tested under high confining pressure. Through Ck0 U and SS tests, the effective and total shear strength parameters are determined. Based on the research above, the distributions between normalized shear strength and depth under different methods are comprehensively analyzed. The results can provide engineering geological parameter analysis experience for the basic design of deepwater marine structures in the south China sea.