N-SPT values observed during testing are not utilized directly in the assessment of soil properties. These values need to be corrected to account for hammer efficiency , borehole diameter,sampling method, rod length and the overburden pressure. Current tool sets the rules to allow the calculations for the correct SPT numbers, N60 and (N1)60.

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.

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. You can activate the tool and then go back to the project page to plot the friction angle with depth.

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.