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Karlsruhe model

The Karlsruhe model, developed by Fuentes and Triantafyllidis (2013)1, is an advanced hydro-mechanical constitutive model for unsaturated soils. Its primary features are the ability to simulate hysteretic water retention behavior (drying and wetting scanning curves) and to couple the retention properties with the soil's mechanical state through the void ratio (\(e\)).

The numgeo keyword reads:

*Hydraulic = Karlsruhe-Model
alpha^d, n^d, alpha^w, n^w, kappa, n, m^e, S_rd, S_rw

The material parameters of the Karlsruhe hydraulic model are given in the following.

  • Bounding Curve Parameters:

    • alpha^d, n^d, S_rd: Van Genuchten parameters for the main drying curve.
    • alpha^w, n^w, S_rw: Van Genuchten parameters for the main wetting curve.

  • Hydro-Mechanical Coupling Parameter:

    • m^e: Exponent controlling the influence of void ratio on the retention curves.

  • Hysteresis Parameters:

    • kappa (\(\kappa_w\) in equations): Controls the slope of the initial reversal from a bounding curve.
    • n (\(n_w\) in equations): Controls the shape of the scanning curves during interpolation.

  1. W. Fuentes and Th. Triantafyllidis. Hydro-mechanical hypoplastic models for unsaturated soils under isotropic stress conditions. Computers and Geotechnics, 51:72–82, 2013. URL: https://www.sciencedirect.com/science/article/pii/S0266352X13000281, doi:https://doi.org/10.1016/j.compgeo.2013.02.002. ↩