Skip to main content
Engineering LibreTexts

17.11: Appendix K- The Properties of the 200 μm Sand

  • Page ID
    35284
  • The sand in the old laboratory DE, with a d50 of 200 μm, is examined for the following soil mechanical parameters:

    1. The minimum and the maximum density, Table K-1: Pore percentages.

    2. The dry critical density, Table K-1: Pore percentages.

    3. The saturated critical density, Table K-1: Pore percentages. The permeability as a function of the density, Table K-2: Permeability as a function of the porosity.

    4. The angle of internal friction as a function of the density, Table K-4: The angle of internal friction as function of the pore percentage.

    5. The d50 as a function of the time, Table K-3: The d50 of the sand as function of the time.

    6. The cone resistance per experiment.

    7. The density in the test stand in combination with the cone resistance.

    The points 7 and 8 need some explanation. With the aid of a Troxler density measuring set density measurements are performed in situ, that is in the test stand. During each measurement the cone resistance is determined at the same position. In this way it is possible to formulate a calibration formula for the density as a function of the cone resistance. The result is:

    \[\ \mathrm{n=\frac{65.6}{C_{p}^{0.082}} \quad\text{ with: n in %, } \mathrm{C_{p}}\text{ in kPa}} \tag{k-1}\]

    In which the cone resistance is determined in a top layer of 18 cm, where the cone resistance was continuously increasing and almost proportional with the depth. The value to be used in this equation is the cone resistance for the 18 cm depth.

    With the aid of this equation it was possible to determine the density for each cutting test from the cone resistance measurements. The result was an average pore percentage of 38.53% over 367 tests.

    By interpolating in Table K-2 it can be derived that a pore percentage of 38.53% corresponds to a permeability of 0.000165 m/s. By extrapolating in this table it can also be derived that the maximum pore percentage of 43.8% corresponds to a permeability of approximately 0.00032 m/s. At the start of the cutting tests the pore percentage was averaged 38%, which corresponds to a permeability of 0.00012 m/s.

    Table K-1: Pore percentages.

    Minimum density

    43.8%

    Maximum density

    32.7%

    Dry critical density

    39.9%

    Saturated critical density

    40.7%-41.7%

    Initial density

    38.5%

     

    Table K-2: Permeability as a function of the porosity.

    Pore percentage

    Permeability (m/s)

    36.97%

    0.000077

    38.48%

    0.000165

    38.98%

    0.000206

    39.95%

    0.000240

    40.88%

    0.000297

    41.84%

    41.84%

    43.07%

    0.000289

    43.09%

    0.000322

    Table K-3: The d50 of the sand as function of the time.

    Date

    d50 (mm)

    22-09-1982

    0.175

    17-12-1984

    0.180

    02-01-1985

    0.170

    08-01-1985

    0.200

    14-01-1985

    0.200

    21-01-1985

    0.200

    28-01-1985

    0.195

    04-02-1985

    0.205

    26-02-1985

    0.210

    Table K-4: The angle of internal friction as function of the pore percentage.

    Pore percentage

    Cell pressure kPa

    Angle of internal friction

    Dry

       

    43.8%

    50

    35.1o

    41.2%

    50

    36.0o

    39.9%

    50

    38.3o

    Saturated undrained

    43.8%

    100

    30.9o

    42.1%

    10

    31.2o

    42.1%

    50

    31.2o

    42.1%

    100

    31.6o

    42.2%

    100

    32.0o

    41.8%

    10

    33.1o

    41.3%

    10

    31.9o

    41.2%

    50

    32.2o

    41.1%

    50

    30.1o

    41.1%

    100

    31.3o

    41.1%

    100

    33.7o

    41.0%

    100

    35.2o

    40.5%

    10

    33.8o

    40.3%

    50

    33.7o

    40.4%

    100

    33.1o

    39.8%

    10

    34.1o

    39.2%

    10

    33.8o

    39.2%

    50

    33.8o

    39.2%

    100

    33.9o

    38.2%

    10

    35.2o

    38.1%

    50

    35.3o

    38.1%

    100

    35.0o

    37.3%

    10

    37.4o

    37.0%

    10

    38.6o

    37.0%

    50

    37.3o

    36.9%

    100

    36.8o

    36.2%

    100

    38.0o

    Screen Shot 2020-08-31 at 6.28.00 PM.png
    Figure K-1: The PSD of the 200 μm sand.
    • Was this article helpful?