In passing, it should be mentioned that it was impractical to use the most popular 

 shear strength test, triaxial shear (Lambe, 1951, p. 122-137; Bishop and Henkel, 1957), 

 on the surficial 3 m or so of the sea-floor sediments examined. It is difficult to obtain 

 a true cylindrical sample of very soft material, and marked variation of strength in 

 short distances precludes using the three contiguous samples that usually are required 

 for valid results. 



More information on sheari strength measurement can be found in standard texts; 

 a good summary is given by Skempton and Bishop (1950). 



it is appropriate for those who would make strength measurements to remember the 

 warning of Burmister (1946), that every test to determine the strength and other impor- 

 tant physical properties of sediments is a research problem; methodology suitable for 

 one set of requirements may not be satisfactory for another. 



Consolidation — The consolidation test is one In which the sample is laterally 

 confined In a ring and compressed between porous plates (ASCE) that allow the escape 

 of Interstitial water. At BUDOCKS, the specially designed fixed-ring consolidometer 

 cell accepts a specimen 1 .25 cm (0.5 In) thick and 4.9 cm (1 .94 In) In diameter 

 (Fig. 9a). Loads are applied either pneumatically (Fig. 9b), or by a lever system on 

 which known weights are hung (Fig. 9c). 



The logarithm of time-fltting method was used In the computations of consolida- 

 tion as a function of time. Test results are presented by plotting the void ratio, e, as 

 a function of the logarithm (to the base 10) of pressure, p, or e-log p curve (Fig. 10). 

 Void ratio is the ratio of the volume of void space, V^, to the volume of solid particles, 

 Vj, In a given sediment mass (ASCE) or 



^s 



The reader Is referred to standard texts (for example, Lambe, 1951, p. 74-87) 

 for more detailed information on consolidation tests. They also will be discussed In 

 the report on consolidation, which Is In preparation. 



21 



