REGRESSION-ANALYSIS OF PHYSICAL AND GEOTECHNICAL PROPERTIES OF SURFACE MARINE-SEDIMENTS

Physical properties, undrained shear strength, and sound velocity of m arine sediments (< 5 m below the seafloor) were measured in the labora tory on gravity and box cores taken in Eckernfoerde Bay, Baltic Sea. S hear wave velocity of surface marine sediments was estimated based on in-situ measured profiles of shear modulus versus depth. Sediments at the study site are mainly soft silty clays, with high water content, h igh void ratio, high organic content, low bulk density, gas bubbles, l ow compressional and shear wave velocity and low shear strength. Based on the sediment properties regression analyses indicate that sound ve locity correlates with sand%, water content, and shear strength for th ese samples. The results indicate that sound velocity may correlate wi th shear strength of marine sediments in a relative uniform environmen t such as nongassy sediment. No usable relationship between sound velo city and sediment properties was found for gassy sediments. Shear wave velocity correlates with shear strength, bulk density, and effective overburden pressure. The shear strength increases with increasing dept h and effective pressure for both gassy and nongassy sediments. Compar ed to gassy sediments, the shear strength of nongassy sediments increa ses more rapidly with effective pressure or depth. Higher-order terms are not necessary in the models for surface sediments.