Model – Modified Hardening Soil

Input Dialog Box

The following input parameters are required for Modified Hardening Soil.

• φ – Friction angle
• c – Cohesion
• ψ – Dilatancy angle

• p_ref – Reference stress
• m – Power for stress dependency

• E_oed,ref – Reference value of the oedometer tangent modulus for the initial loading
• C_SH – Material constant for controlling shear hardening

• E_ur,ref – Reference value of the secant modulus for unloading and reloading
• ν – Poisson's ratio for unloading and reloading

• p^POP/ η^POP – Preconsolidation stress / preconsolidation ratio

These parameters are defined in the specific input tab shown in the image below.

Input Dialog Box – Modified Hardening Soil Model

Additional Notes

Cohesion

When using numerical methods like FEM in geotechnical analysis, it's always a good idea to use a cohesion that's not zero. To do this, you can define a small calculated cohesion between 0.5 and 1.0 kN/m², even for non-cohesive soils.

Power for Stress Dependency

Common values for sand are m = 0.5 and for clay m = 1.0.