Geotechnical characterization of surficial high-porosity sediments in Eckernförde Bay

A. J. Silva, University of Rhode Island
H. G. Brandes, University of Rhode Island
G. E. Veyera, University of Rhode Island

Abstract

Geotechnical studies of high-porosity, fine-grained sediments from Eckernförde Bay, part of the Coastal Benthic Boundary Layer program, included coring, subsampling, and on-board testing during three field experiments, and a laboratory testing program to determine the mechanical properties of the seabed. The sediments consist of high-porosity (86-94%), organic-rich (10-20%) silty clays with varying amounts of methane gas. The surface 5-10 cm are characterized by unusually high water contents (400-600%), very low shear strengths (<1 >kPa), and pronounced shear thinning behavior. Below that depth sediments are somewhat more competent, exhibiting water contents of 250-300% and higher strengths (>1 kPa).