Fault intersection with multiple through-going faults in 3D

PyLith
1

Hi Brad,

I would like to understand how to handle simulations where there are multiple through-going faults. I know that when faults intersect, the through-going fault should come first in the list of interfaces.

But for the case of the figure below, where there are multiple through-going faults, how would you specify the order of the faults in the list of interfaces? If set something like this, then PyLith throws an error during the creation of the cohesive cells:

interfaces = [Fault_3, Fault_2B, Fault_8, Fault_2A]

If I didn’t have Fault_8 in the figure below, then this would work fine:

interfaces = [Fault_3, Fault_2B, Fault_2A]

Similarly, if I remove Fault_3, then this also works fine:

interfaces = [Fault_2B, Fault_8, Fault_2A ]

Note that I made sure that the cohesive cells are created properly with each individual faults.

Let me know what you think about this.

Thank you in advance,
Josimar

Screen Shot 2020-08-21 at 9.38.12 AM
Screen Shot 2020-08-21 at 9.38.12 AM1760×1320 362 KB

2

Let me summarize what I think you want:

  • Fault 3 splits fault 2 into 2A and 2B.
  • Fault 3 terminates at fault 8.
  • Fault 8 terminates at fault 2B.

I think I see the problem. Fault 3 is a through-going fault with respect to fault 2, so we want fault 3 created before 2A and 2B. Fault 8 is a through-going fault with respect to 3, so we want fault 8 created before 3. Fault 2B is a through-going fault with respect to 8, so we want fault 2B created before 8. Obviously, we cannot satisfy all three of these statements simultaneously. Physically, this geometry is possible, but the cohesive cells would have to be inserted in a very specific way with additional constraints on the topology than what we currently have.

A workaround is to make fault 2 a through-going fault and split fault 3 into 3A and 3B. Then the order would be fault 2, fault 8, fault 3A, fault 3B.