FISH function for elastic modulus increment with confining pressure

FLAC
1

Hi all,

I’d like to initialize a non linear distribution of elastic moduli in my FLAC slope model. In particular, I would like to vary the moduli according to the confining pressure (sig2).
I’m therefore trying to write a fish function called “linear_mod_z” but I cannot understand why it’s not working.
It seems that the script does read the sig2(i, j) value.

Here is the script of the function:


def linear_mod_z
	loop i (1,izones)
	  	loop j (1,jzones)
			if z_group(i,j) = 'clays'  then
				bulk_mod(i,j) = (_Km * sig2(i, j) + _Kq) ; Bulk_modulus
				shear_mod(i,j) = (_Gm * sig2(i, j) + _Gq) ; Shear_modulus
			endif
		endloop
	endloop
end

set _Km = 38.517 _Kq = -3.3236 _Gm = 23.11 _Gq = -1.9941

linear_mod_z

I’m using FLAC v.8.

Can anyone tell me where I am wrong?

Thanks a lot in advance.

2

There is no such intrinsic fish function sig2(), you have to calculate the intermediate principal stress based on the stress components, see ps3d.fis from the FLAC installation folder: Itasca\FLAC810\Datafiles\Fish\3-Library\Ps3d

3

Thanks a lot jwang! I will have a look at the suggested documentation.