# Error: \*\*\*both elastic modulii zero in at lease one zone

**URL:** <https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178>\
**Category:** FLAC\
**Created:** [September 20, 2023, 12:44pm UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178 "2023-09-20T12:44:02Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Derek](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@Derek](https://forum.itascainternational.com/u/Derek)\
**Post date:** [September 20, 2023, 12:44pm UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178/1 "2023-09-20T12:44:02Z")

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Hi everyone,  
I am running the stability analysis for a staged construction of tailings dam, I used NorSand model for tailings and clay. At the end of construction, I switched the NorSand of Tailings and Clay to Mohr-Coulomb for the strength reduction method. However, it shows the error of “\*\*\*both elastic modulii zero in at lease one zone”, could anyone provide some insights to this error？  
thanks  
Derek  
;---------------------------FoS calculation---------------  
ini xdisp 0 ydisp 0 yvel 0 xvel 0  
set small

ini ex\_1 0

def de\_par  
loop ii (1,izones)  
loop jj (1,jzones)  
if z\_group(ii,jj)=‘Lower\_silt\_sand’  
ex\_1(ii,jj)=bulk\_current(ii,jj)  
end\_if  
if z\_group(ii,jj)=‘Upper\_silty\_sand’  
ex\_1(ii,jj)=bulk\_current(ii,jj)  
end\_if  
end\_loop  
end\_loop  
end  
de\_par  
;  
model mo group Clay  
model mo group Lower\_silt\_sand  
model mo group Upper\_silty\_sand  
model mo group EM\_Tailings  
model mo group CM\_Tailings  
;  
def su\_peak\_assign  
loop ii (1,izones)  
loop jj (1,jzones)  
if model (ii,jj)#1  
$esy=-(syy(ii,jj)+pp(ii,jj))  
if z\_group(ii,jj)=‘Lower\_silt\_sand’  
$poi\_=0.333  
bulk\_mod(ii,jj)=ex\_1(ii,jj)  
shear\_mod(ii,jj)=3._bulk\_mod(ii,jj)_(1.-2._$poi\_)/(2._(1.+$poi\_))  
tension(ii,jj)=0.  
friction(ii,jj)=30.  
cohesion(ii,jj)=0.   
end\_if  
if z\_group(ii,jj)=‘Upper\_silty\_sand’  
$poi\_=0.333  
bulk\_mod(ii,jj)=ex\_1(ii,jj)  
shear\_mod(ii,jj)=3._bulk\_mod(ii,jj)_(1.-2._$poi\_)/(2._(1.+$poi\_))  
tension(ii,jj)=0.  
friction(ii,jj)=30.  
cohesion(ii,jj)=0.   
end\_if  
if z\_group(ii,jj)=‘Clay’  
$poi\_=0.49  
shear\_mod(ii,jj)=51._100000.  
bulk\_mod(ii,jj)=2.shear\_mod(ii,jj)(1.+$poi\_)/(3._(1.-2._$poi\_))  
tension(ii,jj)=0.  
friction(ii,jj)=0.  
cohesion(ii,jj)=max(10.,0.22_$esy)  
end\_if  
if z\_group(ii,jj)=‘EM\_Tailings’  
$poi\_=0.49  
shear\_mod(ii,jj)=51._100000.  
bulk\_mod(ii,jj)=2.shear\_mod(ii,jj)(1.+$poi\_)/(3._(1.-2._$poi\_))  
cohesion(ii,jj)=0.18_$esy  
tension(ii,jj)=0.  
friction(ii,jj)=0.  
end\_if  
if z\_group(ii,jj)=‘CM\_Tailings1’  
$poi\_=0.49  
shear\_mod(ii,jj)=51._100000.  
bulk\_mod(ii,jj)=2.shear\_mod(ii,jj)(1.+$poi\_)/(3._(1.-2._$poi\_))  
cohesion(ii,jj)=0.24_$esy  
tension(ii,jj)=0.  
friction(ii,jj)=0.  
end\_if  
end\_if  
end\_loop  
end\_loop  
end  
su\_peak\_assign  
solve fos

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<div class="post-metadata">

**Author:** ![jwang](https://avatars.discourse-cdn.com/v4/letter/j/b782af/32.png) [@jwang](https://forum.itascainternational.com/u/jwang)\
**Post date:** [September 20, 2023, 3:34pm UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178/2 "2023-09-20T15:34:21Z")

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Norsand model is a CPP model, when the properties are extracted from or assigned to a zone, an intrinsic fish function named ‘z\_prop()’ should be used, e.g.:

ex\_1(ii,jj)=z\_prop (ii,jj, ‘bulk\_current’)  
z\_prop (ii,jj, ‘bulk\_mod’)=ex\_1(ii,jj)

Check: [Use z\_model(),z\_prop() and z\_group(). to access model and properties](https://forum.itascainternational.com/t/use-z-model-z-prop-and-z-group-to-access-model-and-properties/106)  
or page 2 - 47 in the Fish Reference manual for more details.

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<div class="post-metadata">

**Author:** ![Derek](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@Derek](https://forum.itascainternational.com/u/Derek)\
**Post date:** [September 21, 2023, 3:03am UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178/3 "2023-09-21T03:03:18Z")

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## Hi Wang, Thanks for your reply. I still have the same problem of elastic modulii zero, For the clay and Tailings using NorSand mdoel, is the below code correct, if not, could you please help me revise it?

## if z\_group(ii,jj)=‘Clay’ $poi\_=0.333 z\_prop(ii,jj,‘shear\_mod’)=5100000. z\_prop(ii,jj,‘bulk\_mod’)=2._z\_prop(ii,jj,‘shear\_mod’)_(1.+$poi\_)/(3._(1.-2._$poi\_)) ;cohesion(ii,jj)=0.18\*$esy tension(ii,jj)=0. friction(ii,jj)=0. cohesion(ii,jj)=max(10000.,0.22\*$esy) end\_if

## For the Lower\_silt\_sand using Mohr Coulomb, is the below code correct?

## def de\_par loop ii (1,izones) loop jj (1,jzones) if z\_group(ii,jj)=‘Upper\_silty\_sand’ ex\_1(ii,jj)=bulk\_current(ii,jj) end\_if end\_loop end\_loop end de\_par ; if z\_group(ii,jj)=‘Upper\_silty\_sand’ $poi\_=0.333 bulk\_mod(ii,jj)=ex\_1(ii,jj) shear\_mod(ii,jj)=3._bulk\_mod(ii,jj)_ (1.-2._$poi\_)/(2._ (1.+$poi\_)) tension(ii,jj)=0. friction(ii,jj)=30. cohesion(ii,jj)=0. end\_if

thanks  
Derek

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<div class="post-metadata">

**Author:** ![jwang](https://avatars.discourse-cdn.com/v4/letter/j/b782af/32.png) [@jwang](https://forum.itascainternational.com/u/jwang)\
**Post date:** [September 21, 2023, 2:03pm UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178/4 "2023-09-21T14:03:48Z")

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For NorSand model use: z\_prop(ii,jj,‘shear\_current’)=5100000.  
For Mohr Coulomb model use: bulk\_mod(ii,jj)=xxx and shear\_mod(ii,jj)=xxx

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<div class="post-metadata">

**Author:** ![Derek](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@Derek](https://forum.itascainternational.com/u/Derek)\
**Post date:** [September 21, 2023, 2:47pm UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178/5 "2023-09-21T14:47:50Z")

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Hi Wang,  
do you mean like this?  
for Norsand:  
if z\_group(ii,jj)=‘CM\_Tailings19’  
$poi\_=0.49  
z\_prop(ii,jj,‘shear\_current’)=5100000.  
z\_prop(ii,jj,‘bulk\_current’)=2._5100000_(1.+$poi\_)/(3._(1.-2._$poi\_))  
cohesion(ii,jj)=0.24\*$esy  
tension(ii,jj)=0.  
friction(ii,jj)=0.  
I tried several times, but still get the same error.  
thanks  
Derek

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<div class="post-metadata">

**Author:** ![jwang](https://avatars.discourse-cdn.com/v4/letter/j/b782af/32.png) [@jwang](https://forum.itascainternational.com/u/jwang)\
**Post date:** [September 21, 2023, 3:06pm UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178/6 "2023-09-21T15:06:10Z")

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Shear\_current, and bulk\_current in the NorSand model are read-only properties. You can extract those values from the zones, but are not allowed to modify them.

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<div class="post-metadata">

**Author:** ![Derek](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@Derek](https://forum.itascainternational.com/u/Derek)\
**Post date:** [September 21, 2023, 3:29pm UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178/7 "2023-09-21T15:29:45Z")

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So what is the right code? could you please write it for me?  
thanks!

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<div class="post-metadata">

**Author:** ![jwang](https://avatars.discourse-cdn.com/v4/letter/j/b782af/32.png) [@jwang](https://forum.itascainternational.com/u/jwang)\
**Post date:** [September 21, 2023, 3:34pm UTC](https://forum.itascainternational.com/t/error-both-elastic-modulii-zero-in-at-lease-one-zone/1178/8 "2023-09-21T15:34:18Z")

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Please send your datafiles to FLAC support.