I am working on a 3D FLAC3D model where I have assigned the Plastic-Hardening material model to a zone. After performing an excavation, I am trying to assign improved soil properties under the foundation. While I can successfully assign properties using the Mohr-Coulomb model, I encounter various errors every time I attempt to do the same with the Plastic-Hardening model. Despite my efforts, I am unable to achieve reasonable results.

Could anyone advise on the best approach for assigning improved soil properties under a foundation in a 3D model using the Plastic-Hardening material model? Any insights or suggestions to overcome the errors and achieve realistic modeling outcomes would be greatly appreciated. I am already using initialization of stresses.

Thank you in advance for your assistance.

fish define PHSoilMaterialModel

command

model range create ‘PH’ position-z -300 0 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL0’ position-z -3.0,0.0 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL1’ position-z -7.0,-3.0 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL2’ position-z -24.0,-7.0 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL3’ position-z -74.0,-24.0 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL4’ position-z -128.0,-74.0 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL5’ position-z -178.0,-128.0 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL6’ position-z -228.0,-178 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL7’ position-z -268.0,-228 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHCL8’ position-z -300.0,-268 ;position-x @xit @xft position-y @yit @yft

model range create ‘PHJG’ position-z -320.0,-300 ;position-x @xit @xft position-y @yit @yft

```
zone cmodel assign plastic-hardening range named-range 'PH'
```

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 2.000E+03 friction 25 dilation 0.0 cohesion 1.000E+03 stiffness-50-reference 1.109E+07 stiffness-ur-reference 3.328E+07 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 9.984E+07 exponent 0.5 failure-ratio 0.9 coefficient-normally-consolidation 0.581 range named-range ‘PHCL0’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 1.800E+03 friction 25 dilation 0.0 cohesion 2.000E+03 stiffness-50-reference 1.560E+07 stiffness-ur-reference 4.680E+07 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 1.404E+08 exponent 0.5 failure-ratio 0.9 coefficient-normally-consolidation 0.581 range named-range ‘PHCL1’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 1.950E+03 friction 25 dilation 0.0 cohesion 2.000E+03 stiffness-50-reference 2.434E+07 stiffness-ur-reference 7.301E+07 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 2.190E+08 exponent 0.5 failure-ratio 0.9 coefficient-normally-consolidation 0.581 range named-range ‘PHCL2’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 2.000E+03 friction 30 dilation 0.0 cohesion 3.000E+03 stiffness-50-reference 4.437E+07 stiffness-ur-reference 1.331E+08 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 3.994E+08 exponent 0.5 failure-ratio 0.9 coefficient-normally-consolidation 0.501 range named-range ‘PHCL3’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 2.000E+03 friction 32 dilation 2.0 cohesion 3.000E+03 stiffness-50-reference 5.009E+07 stiffness-ur-reference 1.503E+08 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 4.508E+08 exponent 0.5 failure-ratio 0.9 coefficient-normally-consolidation 0.471 range named-range ‘PHCL4’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 2.000E+03 friction 32 dilation 2.0 cohesion 5.000E+03 stiffness-50-reference 5.616E+07 stiffness-ur-reference 1.685E+08 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 5.054E+08 exponent 0.9 failure-ratio 0.9 coefficient-normally-consolidation 0.471 range named-range ‘PHCL5’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 2.000E+03 friction 32 dilation 2.0 cohesion 1.000E+04 stiffness-50-reference 6.257E+07 stiffness-ur-reference 1.877E+08 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 5.632E+08 exponent 0.9 failure-ratio 0.9 coefficient-normally-consolidation 0.471 range named-range ‘PHCL6’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 2.000E+03 friction 32 dilation 2.0 cohesion 1.500E+04 stiffness-50-reference 6.933E+07 stiffness-ur-reference 2.080E+08 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 6.240E+08 exponent 0.9 failure-ratio 0.9 coefficient-normally-consolidation 0.471 range named-range ‘PHCL7’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 2.000E+03 friction 32 dilation 2.0 cohesion 2.000E+04 stiffness-50-reference 8.389E+07 stiffness-ur-reference 2.517E+08 flag-smallstrain on strain-70 0.00025 stiffness-0-reference 7.550E+08 exponent 0.9 failure-ratio 0.9 coefficient-normally-consolidation 0.471 range named-range ‘PHCL8’

zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 1.900E+03 friction 35 dilation 5.0 cohesion 1.500E+04 stiffness-50-reference 5.819E+08 stiffness-ur-reference 1.746E+09 flag-smallstrain on strain-70 0.00025 stiffness-oedometer-reference 5.819E+08 stiffness-0-reference 5.237E+09 exponent 0.9 failure-ratio 0.9 coefficient-normally-consolidation 0.431 range named-range ‘PHJG’

end_command

end

@PHSoilMaterialModel

After attaching this parameters.

I assign the parameters below:

```
zone group @GrpNameimp range polygon vertices @xt1 @yt1 @zmt @xt2 @yt2 @zmt @xt3 @yt3 @zmt @xt4 @yt4 @zmt position-z @zmat @zimpdepth
zone property pressure-ref 1.000E+05 over-consolidation-ratio 1.0 density 1.900E+03 friction 35 dilation 5.0 cohesion 1.500E+04 ...
stiffness-50-reference 5.819E+08 stiffness-ur-reference 1.746E+09 flag-smallstrain on strain-70 0.003 stiffness-oedometer-reference 5.819E+08 ...
stiffness-0-reference 5.237E+09 exponent 0.55 failure-ratio 0.9 coefficient-normally-consolidation 0.431 range group @GrpNameimp
```