Shear Strength, Q 'P^f' 

 jided Strength, ^ (psf) 



Sand. Sill, Clay (%t 



Figure 8. Sediment properties for Core SM-2, Series IV. 



Test Data 



The testing schedules for Series i 1 1 and Series I V are presented in 

 Tables 1 and 2, respectively. The plate size, area, and average vertical settle- 

 ment rate are indicated for each test. 



Figure 1 1 illustrates the general nature of the bearing pressure— time 

 and displacement— time curves for a typical test. One characteristic apparent 

 from these curves is the amount of displacement which occurs before the 

 pressure begins to increase. Since the device is designed with the bearing 

 plate initially located 3 inches above the elevation of the support pads, this 

 initial displacement, subtracted from 3 inches, yields an estimate of the 

 immediate settlement of the pads due to the placing of the device on the 

 seafloor. 



Another feature of Figure 1 1 is the marked reduction in pressure 

 immediately following the attainment of full deflection. This might indicate 

 that a portion of the peak pressure is velocity dependent or viscous and is 

 subsequently eliminated when motion ceases. By extending this hypothesis 

 it would be concluded that the testing rate is an important experimental 

 parameter, however, it will be seen later that this is not the case. 



10 



