Extended Permeability model based on Olivella&Alonso.

This property must be a medium property, it computes the permeability in dependence of the strain

The base model was proposed in [2] and it was further investigated in [31] . This extended Version features three orthotropic fracture planes.

The model takes the form of

\[ \mathbf{k} = k_\text{m} \mathbf{I} + \sum \limits_{i=1}^3 \frac{b_i}{a_i} \left( \frac{b_i^2}{12} - k_\text{m} \right) \left( \mathbf{I} - \mathbf{M}_i \right) \]

with

\[ \mathbf{M}_i = \vec{n}_i \otimes \vec{n}_i \]

and

\[ b_i = b_{i0} + \Delta b_i \\ \Delta b_i = a_i \langle \mathbf{\epsilon} : \mathbf{M}_i - \varepsilon_{0i} \rangle \]

where

\( k_\text{m} \)	permeability of undisturbed material
\( b_i \)	fracture aperture of each fracture plane
\( b_{i0} \)	initial aperture of each fracture plane
\( a_i \)	mean fracture distance of each fracture plane
\( \vec{n}_i \)	fracture normal vector of each fracture plane
\( \varepsilon_{i0} \)	threshold strain of each fracture plane

Child parameters, attributes and cases

Additional info

Used in the following test data files