*HEADING
POROUS ELASTICITY, HYDROSTATIC COMPRESSION, CAX8R
*NODE
1,0.0,0.0
2,1.0,0.0
3,1.0,1.0
4,0.0,1.0
5,0.5,0.0
6,1.0,0.5
7,0.5,1.0
8,0.0,0.5
*NSET,NSET=ALLNODES
1,2,3,4,5,6,7,8
*ELEMENT,TYPE=CAX8R,ELSET=SOIL
10,1,2,3,4,5,6,7,8
*SOLID SECTION,ELSET=SOIL,MATERIAL=SOIL
*MATERIAL,NAME=SOIL
*POROUS ELASTIC
1.0,0.3
*INITIAL CONDITIONS,TYPE=RATIO
ALLNODES,1.08,0.0,1.08,1.0
*INITIAL CONDITIONS,TYPE=STRESS,GEOSTATIC
SOIL,-100.0,0.0,-100.0,1.0,1.0
*BOUNDARY
1,1
8,1
4,1
2,2
5,2
1,2
*STEP, NLGEOM, UNSYMM=YES
*GEOSTATIC
*DLOAD
SOIL,P2,100.0
SOIL,P3,100.0
*EL PRINT,FREQ=50
S,PRESS,MISES
E,VOIDR
*NODE PRINT,FREQ=50
U,RF
*EL FILE
S,E,VOIDR
*NODE FILE
U, 
*END STEP
*STEP,NLGEOM,INC=50, UNSYMM=YES
*STATIC
0.1,1.0
*DLOAD
SOIL,P2,200.0
SOIL,P3,200.0
*END STEP
*STEP,NLGEOM,INC=50, UNSYMM=YES
*STATIC
0.1,1.0
*DLOAD
SOIL,P2,300.0
SOIL,P3,300.0
*END STEP