Table 12-1 



Relative Density Sample Descriptions 



Date 



Sample 



n 



Description 



Distance from 



Station- 1 

 ft 



Location 



8 Aug 91 



6 

 2 

 4 

 3 



1 

 7 



Post-Erosion test 

 with random waves 



6 



12 



60 



96 



120 



120 



dune 

 berm 



sub-aerial profile 

 sub-aerial profile 

 sub-aerial profile 

 sub-aerial profile 



21 Aug 91 



4B 

 3B 

 5B 

 2B 

 1B 



Pre-Dune erosion 

 Test 1 



6 



12 



24 



32 



36 



dune 



dune 



berm 



sub-aerial profile 



sub-aerial profile 



22 Aug 91 



1C 

 2C 

 3C 

 4C 

 5C 



Post-Dune erosion 

 Test 1 



9 



11 



14 



24 



28 



dune 



dune 



berm 



sub-aerial profile 



sub-aerial profile 



23 Aug 91 



3D 

 2D 

 ID 



Pre-Dune erosion 

 Test 2 



14 

 20 

 24 



dune 

 dune 

 berm 



23 Aug 91 



1E 

 2E 

 3E 

 7E 

 4E 

 6E 

 5E 



Post-Dune erosion 

 Test 2 



12 

 13 

 18 

 20 

 32 

 36 

 36 



dune 



dune 



berm 



berm 



sub-aerial profile 



sub-aerial profile 



sub-aerial profile 



26 Aug 91 



IF 

 2F 

 3F 

 4F 



Post-Seawall Test 1 





 14 

 24 

 36 



toe of seawall 

 upper-area profile 

 sub-aerial profile 

 sub-aerial profile 



The ten pressure gauges were moved to various locations throughout the 

 project. This allowed each instrument to be placed in the most useful position 

 relative to the ongoing experiment. A summary of the pore pressure gauge 

 locations during SUPERTANK is presented in Table 12-2. 



Instrument characteristics. Each pore pressure gauge is powered by 

 10-V DC and operated over a total pressure range of to 5 psi (0 to 

 34.5 kPa). The output of each instrument is very linear with no discernable 

 drift in a 24-hr period. Sensitivity is approximately ±3 mV, with outputs 

 responding at approximately 1 V per 0.5 ft of head. The natural frequency is 

 in the kHz range. Temperature effects are less than ±0.5 percent of full scale 

 for 0° to 50°C. 



Chapter 1 2 Pore Pressure and Sediment Density Measurements 



241 



