Modeling Issues in Plaxis-2D

[SKSA]

Hi there,
I was trying to model a cut soil to simulate the basal heave in narrow braced excavation. Here in this picture I used steel plate. After running the simulation the steel plate has moved down a little bit which is not acceptable. I used bottom point fixed in the steel plate. The soil material is clay. What could be issue? Can you please give your suggestion from your own?

 

[EireChch]

How much has it moved?

 

[geotechguy1]

You haven't really given enough information in your post about how the model is setup and all the input parameters but, thinking rationally about how F.E. models work - you expect to have a stress concentration right at the circled red area, and linear elastic-perfectly plastic F.E. models also usually overpredict upward displacement of the excavation base which your model is also showing. So I'd reason probably what is happening is it's yielding at that point and so you're getting some larger displacements?

Can you show us outputs of stress contours and displacement contours?