geostatic step

[otask]

Dear all,

I am trying to model a 3d soil column using the Mohr-Coulomb and the c3d8r element type.
1. Firstly, I defined only the elastic properties of the soil (E,v,rho) and I applied gravity using the geostatic step (I also defined initial stresses). My problem is that the displacements are not negligible at the end of the analysis... Does anybody knows if I can apply the geostatic defining only the elastic properties of the soil or do I need to define Mohr-Coulomb, Dracker-Prager etc?

2. Then I used Dracker-prager and again there are displacements at the end of the step..

Does anybody know what I am doing wrong?

Many thanks,
Oly.


******MATERIAL PROPERTY**********************
*SOLID SECTION,ELSET=EALL,MATERIAL=SOIL
*MATERIAL,NAME=SOIL
*ELASTIC, TYPE=ISO
**kPa
3.036E4,0.328
*DRUCKER PRAGER, SHEAR CRITERION=Linear
***\Friction angle,\K-value\,dilation angle,\temperature
40.9,1.0,10.,0.
*DRUCKER PRAGER HARDENING, TYPE=COMPRESSION
***\Yield.stress,\Corresponding.plastic.strain
500.,0
*DENSITY
** ML^-3 = t/m^3
1.7
******BOUNDARY CONDITION*********************
*BOUNDARY
BASE, ENCASTRE
**
********INITIAL CONDITION**********************
*INITIAL CONDITIONS,TYPE=STRESS,GEOSTATIC
EALL, 0, 10., -400., -10., 0.5
***INITIAL CONDITIONS,TYPE=STRESS
** ETOP,-5.,0.,-5.,0.
***INITIAL CONDITION,TYPE=SOLUTION, USER
**
**
******STEP DEFINITION************************
******STEP 1 ********************************
**
*Step, name=geo, nlgeom=YES
*Geostatic
**
*DLOAD
EALL,GRAV,10.,0.,-1.,0.
**
*End Step