Traditionally, the methods used to determine the mechanical properties of marine sediments were those used in the field of soil mechanics. These methods are generally acceptable wiien the sediment tested is plastic or at water contents below the liquid limit. However, for predicting in-situ conditions, that is for sediment at water contents above the liquid limit, the problem is complex. Specifically, the determination of shear strength of an unconsolidated- undrained sample by the direct shear method was found to exhibit an angle of internal friction ranging from 19 degrees to 23.5 degrees. This indicates that the shear strength of the sediments is dependent on the normal load applied to it.

http://archive.org/details/directsheartesti1094515667

Lieutenant Commander, United States Navy