Chantier Irrigal

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Soil mechanical properties

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.

Average characteristics of commonly encountered soils
Type of groundDry/WetSubmerged
ΦγΦγ
degreest/m3degreest/m3
Fragmented rock40°235°1.1
Gravel, sands35°1.930°1.1
Sand/gravel
Silts/clays
30°225°1.1
Silts/clays25°1,915°1
Humus organic/clays/silts15°1.8no mean characteristics

Φ: Angle of internal friction (in degrees)
γ: Density (in t/m3)

Average values for backfill modulus of reaction E (a)
Type of soil used for backfillBackfill module of reaction E
DescriptionClassification
(b)
Degree of compaction (Proctor)
Non compacted
(80 à 85 %)
Controlled compaction
(85 à 90 %)
Controlled
and checked compaction
> 90 %
MpaMPaMPa
Clean or slightly silty sand and gravel (elements < 50 mm)B1 B2 B3 D1 D20.72.05.0
Silty or medium clay sand and gravelB4 B50.61.23.0
Flint or millstone clay. Rubble, moraine, eroded rock, coarse alluvium with high percentage of finesC1 C2
with Dmax<250 mm
0.51.02.5
Loam, fine sand, gravel, more or less plastic marl (Ip < 50)A1 A2 A3 B6< 0.30.60.6
Unstable rock: chalk, sandstone, schist. Composite soils (flint and millstone clay, moraine, eroded rock, coarse alluvium with elements that may exceed 50° mmD3
C1 C2
with Dmax>250 mm
R13 R23 R34 R43
0.72.05.0

(a) As per Fascicule 70
(b) Classification as per NF P 11-300/GTR (Road works guide)
(c) Ip = Plasticity index

See also

The various types of pipes can be divided into three categories, depending on their performance.
Underground pipelines are subject to corrosive soils and back