Table 1 Soil indices, moisture—density values, and classification for native soil
Sample No | Geologic unit | Natural moisture content (NMC) (%) | Plastic limit (%) | Liquid limit (%) | Plasticity index (%) | Liquidity index | Sieve sizes in (mm) | 4.75 | 2.36 | 1.18 | 0.6 | 0.425 | 0.3 | 0.15 | 0.075 | pH | AASHTO classification | Unified soil classification system (USCS) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Maximum dry density (kg/m3) (MDD) | Optimum moisture content, (%) (OMC) | Percentage passing sieve no | |||||||||||||||||
7 | 14 | 25 | 36 | 52 | 100 | 200 | |||||||||||||
I | Nkporo Shale | 26.3 | 30.0 | 52.0 | 22.0 | −0.2 | 1620.0 | 14.6 | 100. | 93.9 | 93.9 | 89.8 | 88.4 | 87.3 | 85.5 | 80.1 | 2.27 | A-7-5(20) | OH |
I | New Netim Marl | 15.6 | 33.0 | 48.0 | 15.0 | −1.2 | 2020.0 | 8.6 | 94.7 | 84.0 | 84.0 | 79.9 | 78.0 | 76.2 | 72.6 | 68.4 | 6.97 | A-7-5(11) | MH |
I | Ekenkpon Shale | 27.8 | 38.4 | 52.8 | 14.4 | −0.7 | 1700.0 | 16.6 | 94.0 | 89.0 | 89.0 | 86.6 | 85.8 | 84.8 | 83.0 | 81.4 | 4.28 | A-7-5(15) | OH |
II | Ekenkpon Shale II | 26.2 | 36.5 | 51.5 | 15.1 | −0.7 | 1680.0 | 18.5 | 100. | 99.2 | 99.2 | 97.2 | 95.8 | 94.6 | 91.8 | 90.0 | A-7-5(18) | OH | |