Soil Young's modulus (E), commonly reffred to as soil elastic modulus, is an elastic soil parameter and a measure of soil stiffness. It is defined as the ratio of the stress along an axis over the strain along that axis in the range of elastic soil behaviour. The elastic modulus is often used for estimation of soil settement and elastic deformation analysis.
Soil elastic modulus can be estimated from laboratory or in-situ tests or based on correlation with other soil properties. In laboratory, it can be determined from triaxial test or indirectly from oedometer test. On field, it can be estimated from Standard penetration test, Cone penetration test , pressuremeter or indirectly from dilatometer test.
Typical values of soil Young's molulus for different soils according to USCS
In general, the soil stiffness and elastic modulus depends on the consistensy and packing (density) of the soil. Typical values of soil Young's modulus are given below as guideline.
Typical values of Young's modulus for granular material (MPa) (based on Obrzud & Truty 2012 complied from Kezdi 1974 and Prat et al. 1995)
| USCS | Description | Loose | Medium | Dense |
| GW, SW | Gravels/Sand well-graded | 30-80 | 80-160 | 160-320 |
| SP | Sand, uniform | 10-30 | 30-50 | 50-80 |
| GM , SM | Sand/Gravel silty | 7-12 | 12-20 | 20-30 |
Typical values of Young's modulus for cohessive material (MPa) (based on Obrzud & Truty 2012 compiled from Kezdi 1974 and Prat et al. 1995)
| USCS | Description | Very soft to soft | Medium | Stiff to very stiff | Hard |
| ML | Silts with slight plasticity | 2.5 - 8 | 10 - 15 | 15 -40 | 40 - 80 |
| ML, CL | Silts with low plasticity | 1.5 - 6 | 6 -10 | 10 - 30 | 30 -60 |
| CL | Clays with low-medium plasticity | 0.5 - 5 | 5 -8 | 8 - 30 | 30 - 70 |
| CH | Clays with high plasticity | 0.35 - 4 | 4 -7 | 7 - 20 | 20 - 32 |
| OL | Organic silts | - | 0.5 -5 | - | - |
| OH | Organic clays | - | 0.5 -4 | - | - |
REFERENCES
- Obrzud R. & Truty, A.THE HARDENING SOIL MODEL - A PRACTICAL GUIDEBOOK Z Soil.PC 100701 report, revised 31.01.2012
- Kezdi, A. (1974). Handbook of Soil Mechanics. Elsevier, Amsterdam.
- Prat, M., Bisch, E., Millard, A., Mestat, P., and Cabot, G. (1995). La modelisation des ouvrages. Hermes, Paris.
Citation :
Geotechdata.info, Soil Young's modulus, http://geotechdata.info/parameter/soil-elastic-young-modulus.html (as of September 17.09.2013).