Vane Shear Strength (psi) 

 ).2 0.4 0.6 0.8 



Vane Shear Strength (psi) 

 0.2 0.4 0.6 



m 











m 





(^ Core PB-4 

 El Core PB-5 





«, 







A 



b 





t 





JBi 











m^ 











^ . 











oa 











aOQ 













BO ^ 











o A 



D 









^ 



S 









c 



B 









A 



O 



e 





o 





O 









o 







\ 











\ 









o\ Q 









□ o 



\ 









o N. □ 









o \ 



\ 









Oy o 









o\ 







Q 



o 



O Core SM-2 

 □ Core SM-1 _^ 



O 



o 









□ o 



















o 



Figure 9. Vane shear strength versus 

 depth, Series III. 



Figure 10. Vane shear strength versus 

 depth, Series IV. 



It is felt that this phenomenon is actually attributable to the 

 development of a small amount of drained compression beneath the plate. 

 This effect would be negligible during the penetration process but rather 

 significant after the cessation of motion. Any slight settlement of the plate 

 would result in an expansion of the load transducer leading to a marked 

 decrease in the measured load. Fortunately, this sort of behavior would 

 not affect the validity of the loading curves and might, in fact, be of some 

 use in analyzing the consolidation behavior of seafloor sediments. 



A final important characteristic of this data is the relatively large 

 negative pressure attained at the end of a test as the plate is being withdrawn. 

 This data has been analyzed elsewhere in a study directed toward the predic- 

 tion of breakout forces.'^ 



11 



