Technical solutions
Soils
The data given below covers the generally accepted values for soil characterization. It does not dispense with actual site or laboratory measurements.
The values indicated in the table are those generally accepted for soil characterization. They cannot replace actual site or laboratory measurements.
| Type of ground | Dry/Wet | Submerged | ||
|---|---|---|---|---|
| Φ | γ | Φ | γ | |
| degrees | t/m3 | degrees | t/m3 | |
| Fragmented rock | 40° | 2 | 35° | 1.1 |
| Gravel, sands | 35° | 1.9 | 30° | 1.1 |
| Sand/gravel Silts/clays | 30° | 2 | 25° | 1.1 |
| Silts/clays | 25° | 1,9 | 15° | 1 |
| Humus organic/clays/silts | 15° | 1.8 | no mean characteristics | |
Φ: Angle of internal friction (in degrees)
γ: Density (in t/m3)
| Type of soil used for backfill | Backfill module of reaction E | |||
|---|---|---|---|---|
| Description | Classification (b) | Degree of compaction (Proctor) | ||
| Non compacted (80 à 85 %) | Controlled compaction (85 à 90 %) | Controlled and checked compaction > 90 % | ||
| Mpa | MPa | MPa | ||
| Clean or slightly silty sand and gravel (elements < 50 mm) | B1 B2 B3 D1 D2 | 0.7 | 2.0 | 5.0 |
| Silty or medium clay sand and gravel | B4 B5 | 0.6 | 1.2 | 3.0 |
| Flint or millstone clay. Rubble, moraine, eroded rock, coarse alluvium with high percentage of fines | C1 C2 with Dmax<250 mm | 0.5 | 1.0 | 2.5 |
| Loam, fine sand, gravel, more or less plastic marl (Ip < 50) | A1 A2 A3 B6 | < 0.3 | 0.6 | 0.6 |
| Unstable rock: chalk, sandstone, schist. Composite soils (flint and millstone clay, moraine, eroded rock, coarse alluvium with elements that may exceed 50° mm | D3 C1 C2 with Dmax>250 mm R13 R23 R34 R43 | 0.7 | 2.0 | 5.0 |
(a) As per Fascicule 70
(b) Classification as per NF P 11-300/GTR (Road works guide)
(c) Ip = Plasticity index