When I use strain-softening model in UDEC 7, the element instantly reach failure after tunnel excavation. I am modeling block as a CWFS material to simulate brittle behavior of Sandstone under high stress.
A similar model parameters that I used in 3DEC did work as expected and failure zone appeared around opening where stress reached spalling limit. Please see the attached screenshots and command files for your reference.
I have used both small strain and large strain in the model and this procedure did not help at all.
Please advise what I am missing here to simulate Strain Softening model in UDEC 7.
02_initial_SSII.dat (3.6 KB)