Friction angle together with cohesion defines the shear strength parameters of soil. Its definition is derived from the Mohr-Coulomb failure criterion. It can be determined in the laboratory by direct shear test or triaxial tests or from theoretical correlations with density or N SPT number.

The current tool sets the rules to calculate friction angle for granular soils based on N SPT number.

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 the Foundation Analysis and Design book from Bowles (5th Edition, 1997). The tool also allows for 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).

Lateral earth pressure is the pressure that soil exerts in horizontal direction. It affects the design of retaining walls, basements, tunnels and deep foundations. Current tool estimates the earth pressure at rest, active and passive earth pressure coefficient based on Jaky's formula and Rankine Earth Pressure Theory.