Test Borings

Six sets of borings were drilled between 1976 and 2009

Obtain geotechnical data for the original foundation design at the plant; try to identify potential karst features; provide information for a new turbine/pump

Borehole Video Camera Studies

Eight boreholes were imaged with a video camera. The camera and a supplemental light were slowly lowered through the boreholes to film the walls.

Cavities, fissures and other karst features were panned by the camera

Laboratory Testing

Laboratory testing was performed as part of three previous subsurface investigations.

Laboratory testing included

24 sieve tests; 20 hydrometer tests; 22 specific gravity; 35 natural moisture contents; 3 unit weight tests; 31 Atterberg Limits; 17 unconfined compression tests on soil samples; 8 Unconfined compression tests on rock

Plotted Atterberg Limits on a plasticity chart and natural moisture content versus depth are shown in Figure 10.

Most of the test results are clustered around the A-line on the plot, with liquid limits ranging from 45 percent to 70 percent and classifying as CH or MH soils.

Natural moisture contents of the soils ranged from 7.2 to 33.2 percent with most of the values between 22 and 32 percent.