Rigid Voronoi slope model collapse

I generated a voronoi model in UDEC 6 and made the blocks rigid. When I try to solve it, the block just collapse downwards as shown in picture. I have already applied zero velocity on the lower boundaries. I have also sent the code. Can anyone tell me how I stop this phenomenon. Thank you.

round 0.2
edge 0.4
block 0,0 0,300 100,300 476,100 576,100 576,0
vor edge 10
change mat 1 range -29.3828,605.9828 -14.9911,320.9908
property mat 1 density 2.654E3
group joint ‘weakj:ID104’ range -31.7827,611.3825 -39.5897,334.19
joint model area jks 2E5 jkn 2E8 jfriction 25 range group ‘weakj:ID104’
boundary xvel 0 yvel 0 range -28.7829,628.1816 -11.3913,2.408
boundary xvel 0 yvel 0 range 575.9844,603.5829 -43.1895,144.0003
boundary xvel 0 yvel 0 range -22.1832,1.2155 -22.1907,327.5904
set gravity=0.0 -9.81
solve


Use [In Situ] → [Fix] for the boundaries; The jkn is not stiff enough and causing overlapping. I added an order on it.


round 0.2
edge 0.4
block 0,0 0,300 100,300 476,100 576,100 576,0
vor edge 10
change mat 1 range -29.3828,605.9828 -14.9911,320.9908
property mat 1 density 2.654E3
group joint weakj:ID104 range -31.7827,611.3825 -39.5897,334.19
joint model area jks 2E5 jkn 2E9 jfriction 25 range group weakj:ID104
;boundary xvel 0 yvel 0 range -28.7829,628.1816 -11.3913,2.408
;boundary xvel 0 yvel 0 range 575.9844,603.5829 -43.1895,144.0003
;boundary xvel 0 yvel 0 range -22.1832,1.2155 -22.1907,327.5904
fix range -11.8351,585.3726 -9.9694,8.2065
fix range -11.8351,9.1104 -23.1859,308.801
fix range 571.4983,584.0657 -9.5713,108.771
set gravity=0.0 -9.81
solve

2 Likes

@jscic Thanks a lot. And I had some other questions regarding this model. This time I use the same slope model but using Mohr-coulomb deformable blocks. There is sometimes the overlapping errors (when stiffness are low or near to the young’s modulus), so I increase the stiffness as the software says, but the more I increase the stiffness, the model becomes more stronger and reduces the block deformations I want to see. What I want to see is like the voronoi blocks slide off or roll off as rockfall or slide off the slope like this paper I send below (like toppling or sliding). Can you give me some suggestions on I can achieve this. Thank you.

Paper:
s00603-019-01855-z.pdf (4.6 MB)

My code:

round 0.02
edge 0.04
block 0,0 0,300 100,300 476,100 576,100 576,0
vor edge 10
gen edge 100.0 range region (-25.6195,-47.4439) (-25.6195,319.6272) (633.2542,319.6272) (633.2542,-47.4439)
group zone ‘User:ID143’ range -20.3834,616.7823 -41.3897,325.7905
zone model mohr density 2.654E3 bulk 1.66667E8 shear 7.69231E7 friction 29 cohesion 8.4E4 range group ‘User:ID143’
group joint ‘weakj:ID104’ range -55.7815,604.183 -33.5901,343.1896
joint model area jks 2E5 jkn 2E9 jfriction 25 range group ‘weakj:ID104’
boundary xvel 0 yvel 0 range -20.1652,601.074 -15.8092,2.7352
boundary xvel 0 yvel 0 range 573.8027,637.072 -40.3533,153.818
boundary xvel 0 yvel 0 range -33.2554,2.7427 -7.0824,319.6272
set gravity=0.0 -9.81
solve


One of the Apply Examples in the Itasca’s website should give you a great idea. Please check the link:

https://www.itascacg.com/software/support/examples/rockslide-runout-prediction