This current tool estimates the modulus of elasticity or young's modulus of soil based on theoretical correlations with N SPT number. Correlations available on this tool are mainly based on recommendations from Foundation Analysis and Design book from Bowles (5th Edition, 1997). The tool also allows on estimating young's modulus as an average value from multiple correlations (ie. selecting correlations for gravelly sand and saturated sand and averaging between the two).

Modulus of elasticity or young's modulus (Es) is an elastic soil parameter to measure 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. It is often used for estimation of soil settlement and elastic deformation analysis.

The elastic modulus is normally estimated from in-situ or laboratory tests based on empirical correlations or direct measurements. Field tests that are normally used to estimate young's modulus of soil are standard penetration tests (SPT), cone penetration tests, plate load tests or pressuremeter tests. Laboratory tests to estimate young's modulus are triaxial tests or consolidations tests. Recently, geophysical tests and measurements of shear wave velocities have also been used to estimate modulus of soil.

In general soil stiffness and elastic modulus depends on soil composition (type, gradation, angularity etc), density (compaction), water content and stress history and age of deposit.

Typical values of young’s modulus of soil are presented as a guideline below.