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Approximate values of the tangential restitution coefficient (Rt) for the various morphological categories¶
| MORPHOLOGY | Rt |
|---|---|
| Bedrock | 0.87 |
| Outcrops of rock debris | 0.85 |
| Coarse debris not vegetated | 0.85 |
| Average debris not vegetated | 0.83 |
| Vegetated debris with shrubs | 0.70 |
| Vegetated debris in forest | 0.60 |
| Bare soil or lawn | 0.55 |
| Paved surfaces | 0.90 |
Approximate values of the normal restitution coefficient (Rn) for the various morphological categories¶
| MORPHOLOGY | Rn |
|---|---|
| Bedrock | 0.40 |
| Outcrops of rock debris | 0.38 |
| Coarse debris non-vegetated | 0.35 |
| Average debris not vegetated | 0.31 |
| Vegetated debris with shrubs | 0.30 |
| Vegetated debris in forest | 0.28 |
| Bare soil or lawn | 0.25 |
| Paved surfaces | 0.40 |
Approximate values of the unit weight in Kg/m3¶
| Soil | Minimum value | Maximum value |
|---|---|---|
| Dry gravel | 1800 | 2000 |
| Wet gravel | 1900 | 2100 |
| Compact dry sand | 1700 | 2000 |
| Compact wet sand | 1900 | 2100 |
| Loose dry sand | 1500 | 1800 |
| Loose wet sand | 1600 | 1900 |
| Sandy clay | 1800 | 2200 |
| Hard clay | 2000 | 2100 |
| Semisolid clay | 1900 | 1950 |
| Soft clay | 1800 | 1850 |
| Peat | 1000 | 1100 |
Approximate values of the friction angle, in degrees, for soils¶
| Soil | Minimum value | Maximum value |
|---|---|---|
| Compact gravel | 35 | 35 |
| Loose gravel | 34 | 35 |
| Compact sand | 35 | 45 |
| Loose sand | 25 | 35 |
| Sandy marl | 22 | 29 |
| Fat marl | 16 | 22 |
| Fat clay | 0 | 30 |
| Sandy clay | 16 | 28 |
| Silt | 20 | 27 |
Approximate values of cohesion in Kg/cm2¶
| Soil | Value |
|---|---|
| Sandy clay | 0.20 |
| Soft clay | 0.10 |
| Plastic clay | 0.25 |
| Semisolid clay | 0.50 |
| Solid clay | 1 |
| Tenacious clay | 2÷10 |
| Compact silt | 0.10 |
Approximate values of the elastic module, in Kg/cm2¶
| Soil | Maximum value of E | Minimum value of E |
|---|---|---|
| Very soft clay | 153 | 20.4 |
| Soft clay | 255 | 51 |
| Medium clay | 510 | 153 |
| Hard clay | 1020 | 510 |
| Sandy clay | 2550 | 255 |
| Loess | 612 | 153 |
| Silty sand | 204 | 51 |
| Loose sand | 255 | 102 |
| Compact sand | 816 | 510 |
| Clayey schist | 51000 | 1530 |
| Silt | 204 | 20.4 |
| Loose sand and gravel | 1530 | 510 |
| Compact sand and gravel | 2040 | 1020 |
Approximate values of the Poisson ratio for soils¶
| Soil | Maximum value of n | Minimum value of n |
|---|---|---|
| Saturated clay | 0.5 | 0.4 |
| Not saturated clay | 0.3 | 0.1 |
| Sandy clay | 0.3 | 0.2 |
| Silt | 0.35 | 0.3 |
| Sand | 1.0 | -0.1 |
| Gravelly sand commonly used | 0.4 | 0.3 |
| Loess | 0.3 | 0.1 |
| Ice | 0.36 | |
| Concrete | 0.15 |
Approximate values of specific weight for some rocks in Kg/m3¶
| Rock | Minimum value | Maximum value |
|---|---|---|
| Pumice | 500 | 1100 |
| Volcanic tuff | 1100 | 1750 |
| Tufaceous limestone | 1120 | 2000 |
| Coarse sand dry | 1400 | 1500 |
| Fine dry sand | 1400 | 1600 |
| Wet fine sand | 1900 | 2000 |
| Sandstone | 1800 | 2700 |
| Dry clay | 2000 | 2250 |
| Soft limestone | 2000 | 2400 |
| Travertine | 2200 | 2500 |
| Dolomite | 2300 | 2850 |
| Compact limestone | 2400 | 2700 |
| Trachyte | 2400 | 2800 |
| Porphyry | 2450 | 2700 |
| Gneiss | 2500 | 2700 |
| Serpentine | 2500 | 2750 |
| Granite | 2550 | 2900 |
| Marble | 2700 | 2750 |
| Syenite | 2700 | 3000 |
| Diorite | 2750 | 3000 |
| Basalt | 2750 | 3100 |
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