Calculation of the Modulus of Horizontal Reaction of Subsoil Er
The modulus of a horizontal reaction of subsoil can be determined when knowing the pressuremeter modulus Em and coefficient αp as:
where: | Em | - | |
αp | - | rheological factor of soil (see the table below) |
Reference values Em and Plim
Soils | Em[Mpa] | Plim [MPa] | |
cohesionless | loose | 0 - 3.5 | 0 - 0.5 |
medium dense | 3.5 - 12 | 0.5 - 1.5 | |
dense | 12 - 22.5 | 0.5 - 2.5 | |
very dense | > 22.5 | > 2.5 | |
cohesive | slush | 0 - 2.5 | 0 - 0.2 |
soft | 2.5 - 5 | 0.2 - 0.4 | |
stiff | 5 - 12 | 0.4 - 0.8 | |
solid | 12 - 25 | 0.8 - 1.6 | |
hard | > 25 | > 16 |
Values of rheological factor αp for various soil conditions
Type of soil | Peat | Clay, silt | Sediment | Sand | Sand and gravel | ||||
αp | Em / Plim | αp | Em / Plim | αp | Em / Plim | αp | Em / Plim | αp | |
preconsolidated | 1 | > 16 | 1.0 | > 14 | 0.67 | > 12 | 0.5 | > 10 | 0.33 |
normally consolidated | 1 | 9 - 16 | 0.67 | 8 - 14 | 0.5 | 7 - 12 | 0.33 | 6 - 10 | 0.25 |
underconsolidated | - | 7 - 9 | 0.5 | 5 - 8 | 0.5 | 5 - 7 | 0.33 | - | 0.25 |
Literature:
Menard, L. F.: Proceedings of the 6th International Conference on Soil Mechanics and Foundation Engineering, Montreal, Vol. 2, 1965, pp. 295 - 299 (table 2.29 a 2.30).