ABSTRACT 



Shear strength, expressed as cohesion, was measured by 

 compression and laboratory vane tests on short, usually con- 

 tinuous samples of 30 sediment cores collected by the Hydro- 

 graphic Office from water depths of 400 to 5,120 m in 8 areas 

 of the North Atlantic, West Mediterranean, and Central Pacific. 

 Clayey silt- and silty clay-size sediments were predominantly 

 of terrigenous origin. The least cohesion measured is about 

 4.2g/cm2 and the maximum 234g/cm2. Although cohesion 

 usually increased with depth in the cores, fluctuations in the 

 strength-depth profile are the rule rather than the exception. 

 Validity of strength data, in light of disturbance caused by both 

 piston and gravity core sampling and other forms of disturb- 

 ance, was considered with the conclusion that the cohesions 

 reported are sufficiently reliable for engineering use at the 

 present time. Shear strength and laboratory-determined 

 consolidation data are applied, with numerical examples, to 

 the computation of sea-floor sediment ultimate bearing 

 capacity and consolidation under structural loads. 



