Error 111

Question

Hello, 
 I am attempting to model a plate subject to an upward imposed displacement in a soil mass with two soil layers (see figure below). I activated the plate, the displacement and both soil polygons and then started the calculation. 
 This resulted in Error 111. Have I missed something in the setup to stop the soil from collapsing?

Stefanos Papavasileiou · Answer

Dear Sean, 
 The comment from Ari Surya Abdi is relevant, indeed. 
 There might be various reasons why this failed. Note that by putting the plate at the Xmin PLAXIS will assume you run a half symmetric model or a circular footing in case of axisymmetry being used. 
 In general, for a soil body collapse error, in order to find out what the mechanism for failure is, and so possibly determine the cause, these Output plots should be inspected: 
 
 deformed mesh 
 total displacements (shaded plot) 
 incremental displacement (shaded plot and/or arrows) 
 total deviatoric strain (shaded plot) 
 incremental deviatoric strains (shaded plot) 
 plastic points 
 when applicable: excess pore pressures (pexcess) 
 
 A combination of these plots will usually give insight into what is happening.