I’m trying to apply imposed displacements on a line support beneath a body of soil (Quad elements).

However, looking through the sofiload module It would seem that this isn’t possible?

I can however find imposed displacements for Nodes, so I guess I could loop it over the nodes an apply it that way.

My next problem however is that it apparently it’s not legal to apply imposed displacements in a 2DSN system.

I get the following error message:

```
+++++ error no. 2020 in program SL_IA_KNOT ; input line: 11
Illegal load type for this system LC 1055 on
```

SO… how do I go about applying an imposed displacement to my model?

I have made a small test model shown below:

```
+prog aqua urs:35.1
UNIT 6
head Materials
ECHO FULL NO
MAT 1 E 35000 mue 0.3
SREC 1 H 10000 B 10000 MNO 1
sto#Emod_s 200 ! Young's modulus [N/mm2] ! Insignificant
sto#nu_s 0.32 ! Poisson's ratio [-]
sto#gam_s 25 ! specific weight [kN/m3] ! Insignificant
sto#phi_s 33.4 ! friction angle [°]
sto#coh_s 54 ! cohesion [kN/m2] ! Insignificant
sto#psi_s max(0,#phi_s-30) ! dilatancy angle [°] non-associated ! Insignificant
sto#H 500 ! Interface width [mm]
sto#Emod #Emod_s*(#nu_s+1)*(2*#nu_s-1)/(#nu_s-1)
MAT 10 e #Emod mue #nu_s TITL 'Upper till'
NMAT 10 MOHR P1 #phi_s P2 #coh_s P4 #psi_s
mat 15 e #Emod mue #nu_s TITL 'Interface'
bmat 15 mref 15 h 0.01[m] mue tan(2/3*#phi_s) crac 0
END
+prog sofimshc urs:35.2
head Geometry
SYST 2DSN GDIV 200000 GDIR NEGY
$ SYST SPAC GDIV 200000 GDIR NEGY
CTRL MESH 2+32
CTRL HMIN 250
ECHO FULL NO
UNIT 6
SPT 12 X -#H Y 0 fix ff
SPT 13 X -#H Y -10000
SPT 21 X 0 Y 0
SPT 22 X 0 Y -10000
SPT 23 X 10000 Y -10000
SPT 24 X 10000 Y 0
SLN 21 21 22 fix px ! Left
SLN 22 22 23 fix py ! Bottom
SLN 23 23 24 fix px ! Right
SLN 24 24 21 ! Top
SAR 1 MNO 10
SARB TYPE OUT na 21 ne 22
SARB TYPE OUT na 22 ne 23
SARB TYPE OUT na 23 ne 24
SARB TYPE OUT na 24 ne 21
END
+prog sofiload urs:35.3
LC 3 TYPE 'NONE' TITL 'Imposed Displacement'
NODE NO 1055 TYPE WZZ 100[mm]
END
+prog TALPA urs:39.6
SYST PROB NONL iter 200
LC 3
END
```