Dear all,

I have a problem regarding critical initial time step in poroelastic material during consolidation process.

As we know, for implicit integration method, it's unconditionally stable. But for the consolidation of poroelastic material,

there is a critical time step t_critical derived by Vermeer and Verruijt (1981), this has also been inclued in the abaqus software (http://129.25.22.58:2180/v6.7/books/exa/default.htm).

As far as I know, using a initial time step delta_t<t_critial, there will be ossolication in the pressure results.

Hi!
In the terzaghi equation, there is a constant M (some books call is elastic oedemetric coefficient).
Since the terzaghi equation is a special case for the general 3D biot equations under oedemetric testboundary conditions, does any book or material explain the derivation?
If I want to mode the terzaghi problem using 3D model in FE program, the M is known, then how to get thecorresponding values of young's modulus and poisson's ratio in order to give the same response from the 3D model?
Thanks for your attention. Any suggestions would be appreciated.

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