Damping, mass scaling, timestep for bonded block rockslide runout

Hi all, I’m playing around trying to create a trigon bonded block model of a step-path slope failure. The attached image shows my 200m high slope with 5m edge length trigon blocks. To be able to query stresses in the rock mass, I am using deformable blocks with a coarse mesh (~1 zone per trigon block. All contacts have jkn = 6e9 and jks = 2e9.

The model runs fine up to the formation of the step-path failure surface, using local damping with a factor of 0.1.

However, I am struggling to find an efficient combination of damping/mass scaling/timestep settings to enable reasonable computation time for the runout and comminution of the step-path wedge. I note the checkerboard example back from UDEC v6 has auto damping.

I have tried various damping settings but haven’t figured out the most efficient way to speed up the model.

I have tried partial mass scaling with "block mechanical mass-scale on timestep 0.1 or 0.01, still no luck. Have tried deleting small blocks in the range of area -99,1m2; this doesn’t seem to be enough to speed it up.

Keen to know if anyone can point me in the right direction. There are only 1600 blocks in the model.

Can provide more details if needed. Thanks for any help,

Zack


FYI here is an image showing the step-path wedge after the rock bridges have failed.