Time-dependent jointed rock response

Hi,
Can I use a time-dependent (Burgers/CVISC/WIPP) creep model for zones and a non-time-dependent (Elastic/MC-slip/CY) model for joints? What result would such a combination have in simulating a jointed rockmass?
Let me know your thoughts.
Thanks,
Vijay

Hi!

I’m no expert in dynamic models, here, so I’m just sharing my thoughts.

To me, there is no reason why you could not do so: a time-dependent matrix versus a static joint mostly implies that the joint response is immediate (or at least, way faster than the matrix’s).

However, I am not sure that any models combination would be relevant.
Indeed, if we consider that a joint results from the rupture of its host rock, I would expect the joint to inherit its properties (or at least some of them) from the nature of its host rock. For example, a rigid and/or brittle rock would a priori create a brittle joint, and a ductile rock would create a ductile joint. This question becomes even more complex if you consider that joints infills can alter their initial properties (e.g., calcareous deposits would bring a more fragile joint, and argillaceous would bring a more ductile one). And obviously, dynamic models give additional complexity.

Maybe you can start off with simple models and do step-by-step evolutions:

  • elastic matrix / elastic joint
  • viscous matrix /elastic joint
  • elastic matrix / Mohr-Coulomb joint
  • viscous matrix / Mohr-Coulomb joint

After a (very) brief check on the literature, I could not find publications regarding this subject.

Hope you can get some interesting results!

Regards,

Théophile