properties of rock

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2018-07-27
2018-08-12

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• 2018-07-13 by shiv
 Luc Scholtès (luc) said on 2018-06-19: #1

Hi there,

The main difficulty here is to generate an assembly with the shape of a slope. There is actually no "ready to use" method for doing so but a first workaround would consist in having a look at this section of the doc:

then, you should have a look at the examples provided in the trunk/example/jointedCohesiveFrcitionalPM/ folder where you will find several scripts which will help you a lot since there is, in there, all the material needed to create a simulation where a cylindrical sample containing a persistent fracture plane (with a given dip) is subjected to gravity (which is basically what you want to achieve with a slope geometry instead of the cylinder).

Regarding the "granitic rock properties" of the slope material, this will have to do with the definition of the parameters in your simulation and you could have a look at the following ref to make up your mind about it:

https://www.sciencedirect.com/science/article/pii/S0022509612002268?via%3Dihub

Please have a look at all this and let us know how it goes.

Cheers

Luc

 Jérôme Duriez (jduriez) said on 2018-06-20: #2

Hi,

In terms of examples of a (cubic) slope with some fracture, you may look specifically at

(that's in the folder mentioned by Luc)

 Luc Scholtès (luc) said on 2018-06-20: #3

Right, it is actually a cubic sample and not a cylindrical one that is used in the examples.

Thanks Jerome for the precision.

 shiv (shivpreet.ce15) said on 2018-06-28: #4

Thanks for the help Luc and Jerome. I am trying to model it using your given references but can you help me how can I calculate factory of safety of rock slope with given dip and strike using any appropriate method.

 Jérôme Duriez (jduriez) said on 2018-06-28: #5

You may look for instance 4.1 of [Bonilla2015] (https://www.yade-dem.org/doc/publications.html#journal-articles)

 shiv (shivpreet.ce15) said on 2018-06-29: #6

Thank you for help Jerome.But I have tried drawing a slope on autocad 2017 . But I am n't able to understand how to convert my drawing into GTS format which can be used in YADE.

 Chareyre (bruno-chareyre-9) said on 2018-06-29: #7

Is there a *.stl format with autocad?

Le ven. 29 juin 2018 22:32, Shivpreet sharma <
<email address hidden>> a écrit :

> Question #670255 on Yade changed:
>
>
> Shivpreet sharma is still having a problem:
> Thank you for help Jerome.But I have tried drawing a slope on autocad
> 2017 . But I am n't able to understand how to convert my drawing into
> GTS format which can be used in YADE.
>
> --
>
> _______________________________________________
> Post to : <email address hidden>
>
>

 shiv (shivpreet.ce15) said on 2018-06-30: #8

Yes it is there *.stl format but can we used this in YADE???

 Chareyre (bruno-chareyre-9) said on 2018-06-30: #9

I think stl is the most used format with yade, but not expert of this part.
You may check the doc of the import functions.
Bruno

Le sam. 30 juin 2018 07:38, Shivpreet sharma <
<email address hidden>> a écrit :

> Question #670255 on Yade changed:
>
>
> Shivpreet sharma is still having a problem:
> Yes it is there *.stl format but can we used this in YADE???
>
> --
>
> _______________________________________________
> Post to : <email address hidden>
>
>

 Deepak (deepak-kn1990) said on 2018-06-30: #10

Hello,

There is an utility called stl2gts, which can triangulate the surfaces
using gts. Several examples generating sphere packs are here[2]:
[1]http://manpages.ubuntu.com/manpages/xenial/man1/stl2gts.1.html

On Sat, Jun 30, 2018 at 11:42 AM, Chareyre <

> Question #670255 on Yade changed:
>
>
> Chareyre proposed the following answer:
> I think stl is the most used format with yade, but not expert of this part.
> You may check the doc of the import functions.
> Bruno
>
> Le sam. 30 juin 2018 07:38, Shivpreet sharma <
> <email address hidden>> a écrit :
>
> > Question #670255 on Yade changed:
> >
> > Status: Answered => Open
> >
> > Shivpreet sharma is still having a problem:
> > Yes it is there *.stl format but can we used this in YADE???
> >
> > --
> >
> > _______________________________________________
> > Post to : <email address hidden>
> > More help : https://help.launchpad.net/ListHelp
> >
> >
>
> --
>
> _______________________________________________
> Post to : <email address hidden>
>

 shiv (shivpreet.ce15) said on 2018-07-01: #11

Thanks for help all of you.I have Converted stl drawing into gts but the problem which I am facing is that how to add spheres in this gts with predefined material properties.I have tried looking an example from the below link

But it's doesn't help me because he was adding in left out space which doesn't consist facets.

I have attached my gts drawing:

 shiv (shivpreet.ce15) said on 2018-07-01: #12

And this is my code which I have used till now for further reference:

import gts, os.path, locale

idTissue=O.materials.append(FrictMat(young=500.0,poisson=.35,frictionAngle=.6,label="concrete"))
pred=pack.inGtsSurface(surf)
aabb=pred.aabb()

dim0=aabb[1][0]-aabb[0][0];
dim0 = dim0/2.0
# small

O.bodies.append(pack.gtsSurface2Facets(surf,wire=True))

 Luc Scholtès (luc) said on 2018-07-02: #13

Alright,

From what I understand, your problem is related to the generation of a packing of particles using the pack.inGtsSurface().

I am sorry but I don't understand this:

"But it's doesn't help me because he was adding in left out space which doesn't consist facets."

I am a bit clueless but I'll give you an example script below that works for a simple mesh (a cube) and I would suggest that you try to make the script work (you will have to create the cube.gts on your own) before going into a more complex configuration. At first, I would suggest that you try to generate a "regular packing" in your previously generated cube (using the regularHexa() function) and then, when you are sure that it works, you can experiment with the random packing functions.

###

from yade import pack, export, ymport
import gts, os.path, locale

#### control parameters
mesh='cube' #name of gts mesh
sizeRatio=10. # defines discretisation (sizeRatio=meshLength/particleDiameter)

#### import mesh
locale.setlocale(locale.LC_ALL,'en_US.UTF-8') #gts is locale-dependend. If, for example, german locale is used, gts.read()-function does not import floats normally

print 'closed? ', surface.is_closed()

#### generate packing
if surface.is_closed():
pred=pack.inGtsSurface(surface)
# get characteristic dimensions
aabb=pred.aabb()
dim=pred.dim()
center=pred.center()
minDim=min(dim[0],dim[1],dim[2])
# define discretisation
print center, dim, ' | minDim=', minDim, ' | diameter=', 2*radius
### packing functions
# non periodic packing
# periodic packing
### if you want to translate the surface away from the packing
#surface.translate(dim[0],0,0)

#### import mesh
O.bodies.append(pack.gtsSurface2Facets(surface,color=(0.8,0.8,0.8),wire=True))

#### export packing in a text file
export.text(mesh+'_'+str(int(sizeRatio))+'.spheres')

#### open the GUI to see the packing and the mesh

 shiv (shivpreet.ce15) said on 2018-07-02: #14

Hello Luc,

For more explanation of this line I have attached link you can check it out what i want to express "But it's doesn't help me because he was adding in left out space which doesn't consist facets."

Also I have tried execution of above code but the similar result is obtaining which I have showed in above link.

I have attached my Drawing STL and GTS format

After reading your code even I have tried drawing my model using mesh modelling in autocad but the result are same.
I have attached that drawing link also:

 Luc Scholtès (luc) said on 2018-07-02: #15

The problem comes from your gts file: the facets are wrongly orientated so the packing function fills the outside inside of the inside. I guess this is something that you can change directly in the mesh generator.

ANW, have a look at this previous thread:

I just did what Jan suggested (comment #5) with your gts file and it works (with the script I provided above).

Thank you Jan ;)

Luc

 Luc Scholtès (luc) said on 2018-07-02: #16

Sorry: "outside instead of the inside"

 shiv (shivpreet.ce15) said on 2018-07-02: #17

Thanks a Lot Luc that has solved my problem.I just need more help regarding (comment #2). How can I add a particular joint dip angle in this gts file as in that code they have done in another way.Also can you help how can I calculate factor of safety of such slope
as I have the read given link provided in (comment #5) but I am not able to understand it how will I execute that in YADE.

 Luc Scholtès (luc) said on 2018-07-03: #18

Please have another look at the files in the /trunk/examples/jointedCohesiveFrictionalPM/ folder. Read the README file and you should be able to run your simulation.

The process is as follows (there is another more concise option for advanced users but this one presents the advantage to define each step explicitly):

1 - create a packing to represent the slope with the packInGtsSurface.py (from a .gts file)
2 - create a joint as a meshed surface (.stl). You can create the surface with the same software that you used to create the slope geometry (the .gts file) or you can try to create it directly from inside the yade script as explained in the gravityBis.py. At first, I would suggest to create it from the software.
3 - At this stage, you have a packing (.spheres) and a joint (.stl) and you need to identify the particles belonging to each side of the joint. You need to launch the identificationSphereOnJoint.py to do so. Then, you'll get 2 new files containing the information needed to run your simulation.
4 - Run your simulation (see gravityLoading.py for a simple simulation where the slope first stabilizes under gravity and then the joint is activated).

Once you are familiar with this, you will be able to think about the calculation of the FoS. If you want to calculate the FoS of a slope containing a single persistent joint, you don't need to run a numerical simulation. Then, if you plan to define rock bridges in your model (non persitent joints), you will have to define a FoS. Bonilla proposed one FoS based on a strength reduction method which relates the strength of the rock material at failure to its initial strength. This FoS is valid only if you have rock bridges which stabilize the slope.

Please, try to open more specific questions next time so we know exactly the problem you are facing.

 shiv (shivpreet.ce15) said on 2018-07-05: #19

Thanks for the help, Luc. Next time I will remember to be more specific about my problem

 shiv (shivpreet.ce15) said on 2018-07-13: #20

I have tried executing the steps as suggested by Luc in comment#18.But i am facing problem in executing in running gravityLoading.py. It is showing the error :

execfile(script,globals()) File "gravity.py", line 84, in <module>
O.bodies[refPoint].shape.color=(-1,-1,-1)
NameError: name 'refPoint' is not defined

and following documents related for execution of that script:

 shiv (shivpreet.ce15) said on 2018-07-14: #21
 shiv (shivpreet.ce15) said on 2018-07-14: #22
 Luc Scholtès (luc) said on 2018-07-16: #23

Hi,

'refPoint' is not defined simply means that the variable 'refPoint' is not defined.

This refPoint is defined in the original script as one of the particle located on the top corner of the moving part of the cubic sample (see lines 78 to 88 in your script). It is used afterward to monitor the velocity and displacement of the moving block (see line 108 and 109 in the recorder). My guess is that the test done in line 79 (which aims at finding a particle at the top of the 'slope') is not adapted to your geometry and thus the reference point (which is a particle) does not exist in your case.

You then have 2 solutions to avoid the error message:

- comment every lines related to this 'refPoint' (but you will not have any record of the slope movements)

Luc

 Jérôme Duriez (jduriez) said on 2018-07-16: #24

Hi,

The error seems to be quite basic: I guess you modified the initial script [*] and removed the definition of refPoint (initially at [**]), which was not a good idea.

I would suggest you compare (using e.g. kompare software) your new script with the initial one to remember what changes you did and re-make a functional script.

 shiv (shivpreet.ce15) said on 2018-07-27: #25

Hi,
I haven't edited the initial script but even I haven't done the changes in the initial script according to model. I have tried doing it but I am not getting body id of the particle located on top corner of moving part.

Dimensions are length -11.24 ,width -20 ,height -8.

The model figure is attached below.

 Launchpad Janitor (janitor) said on 2018-08-12: #26

This question was expired because it remained in the 'Open' state without activity for the last 15 days.