Ground Water Pressure - Piezometers
WARNING: Provisional Data, subject to revision
The site has seven piezometers. Four of the piezometers in hole B-1are embedded in a grout consisting of bentonite and Portland cement and are capable of measuring negative pressures when the surrounding soil is partially saturated or unsaturated. The three piezometers at sites B-3, 4 and 5 are each embedded in a sand pack at the bottom of the borehole which was then filled with grout. Pore pressures are reported in hectoPacsals (hPa). One hectoPascal is roughly equivalent to the pressure exerted by a 1-cm-deep column of water. Six of the piezometers are temperature-compensated vibrating-wire transducers (Slope Indicator, model 52611024)* that have a range of -345 to +3448 hPa (or -352 to +3515 cm of water), resolution of ±0.025%FS about (±0.95 hPa or ±0.96 cm of water) and accuracy of ±0.1% (±3.8 hPa or ±3.9 cm of water). One of the piezometers is a temperature compensated vibrating strip transducer (Slope Indicator)* with similar range and resolution.
Pore pressure in hole B1, last 4 days
Pore pressure in holes B3, B4, and B5, last 4 days
Recent Piezometer measurements, daily median
| Date | B1_91cm, hPa | B1_503cm, hPa | B1_564cm, hPa | B1_604cm, hPa | B3_294cm, hPa | B4_290cm, hPa | B5_360cm, hPa |
|---|---|---|---|---|---|---|---|
| 4/21/2008 | 114.56 | -60.997 | -55.831 | -35.895 | -34.718 | -21.855 | -14.085 |
| 4/22/2008 | 114.34 | -62.004 | -57.270 | -37.556 | -35.034 | -24.944 | -17.941 |
| 4/23/2008 | 114.13 | -62.171 | -56.293 | -37.707 | -35.113 | -20.549 | -18.830 |
| 4/24/2008 | 114.15 | -60.269 | -53.980 | -34.988 | -35.061 | -15.547 | -8.4855 |
| 4/25/2008 | 114.20 | -58.873 | -52.464 | -33.931 | -34.929 | -15.089 | -8.7195 |
| 4/26/2008 | 114.30 | -58.181 | -51.878 | -32.871 | -34.739 | -16.781 | -5.3098 |
| 4/27/2008 | 114.93 | -58.012 | -52.006 | -32.299 | -34.318 | -19.745 | -12.315 |
| 4/28/2008 | 115.36 | -58.537 | -53.024 | -32.844 | -35.533 | -23.065 | -15.690 |
| 4/29/2008 | 116.57 | -58.820 | -52.999 | -33.450 | -36.005 | -22.145 | -17.440 |
| 4/30/2008 | 117.34 | -57.954 | -51.791 | -31.608 | -35.140 | -17.601 | -13.205 |
| 5/01/2008 | 117.79 | -57.021 | -50.794 | -32.089 | -36.400 | -19.428 | -13.747 |
| 5/02/2008 | 118.28 | -56.852 | -50.660 | -31.727 | -36.034 | -20.460 | -6.2482 |
| 5/03/2008 | 118.76 | -56.871 | -50.249 | -30.793 | -36.373 | -19.931 | -14.698 |
| 5/04/2008 | 119.58 | -56.469 | -50.049 | -30.699 | -36.926 | -22.067 | -14.586 |
| 5/05/2008 | 120.21 | -56.660 | -49.967 | -31.185 | -36.559 | -22.009 | -17.276 |
| 5/06/2008 | 121.00 | -56.390 | -49.377 | -29.919 | -37.057 | -20.749 | -13.543 |
| 5/07/2008 | 121.90 | -55.764 | -48.452 | -28.710 | -37.267 | -18.811 | -16.672 |
| 5/08/2008 | 122.62 | -55.470 | -48.472 | -27.836 | -37.451 | -20.913 | -13.092 |
| 5/09/2008 | 123.03 | -55.211 | -48.323 | -28.257 | -37.496 | -22.205 | -18.146 |
| 5/10/2008 | 123.15 | -55.716 | -48.704 | -28.679 | -37.661 | -22.865 | -21.074 |
| 5/11/2008 | 123.68 | -55.182 | -47.856 | -27.505 | -38.023 | -20.062 | -14.239 |
| 5/12/2008 | 123.71 | -54.585 | -47.189 | -27.716 | -38.680 | -21.437 | -19.435 |
| 5/13/2008 | 123.97 | -54.128 | -46.500 | -27.323 | -38.995 | -18.968 | -17.256 |
| 5/14/2008 | 124.33 | -52.662 | -44.961 | -25.000 | -38.286 | -15.422 | -13.256 |
| 5/15/2008 | 124.74 | -52.571 | -45.324 | -28.256 | -39.915 | -21.173 | -19.558 |
| 5/16/2008 | 125.66 | -53.610 | -45.895 | -25.629 | -40.173 | -22.844 | -25.849 |
| 5/17/2008 | 126.86 | -53.821 | -45.890 | -29.312 | -39.987 | -22.933 | -31.655 |
| 5/18/2008 | 128.48 | -54.014 | -46.166 | -25.511 | -41.617 | -23.672 | -32.803 |
| 5/19/2008 | 130.07 | -54.952 | -46.603 | -26.176 | -40.803 | -24.497 | -38.475 |
| 5/20/2008 | 131.56 | -55.302 | -46.158 | -26.843 | -40.954 | -23.262 | -34.642 |
