Calculation failed, will soil body inside excavation zone "collapse"?

Proved, collapse due to wrong water condition setting.

"Global" will cause the lower part's pore pressure really higher than surface, and super heave!

Hello William,

Great catch. Indeed, most of the times the boundary and soil conditions are to be blamed for incorrect results.

A tip is to always check the Preview of the phase before calculation to ensure that the steady-state pore water pressures are defined properly. This is a quick first step.

Of course with a groundwater flow analysis, the model behaviour can be affected by the water flow, which is a result you can only see during or after the analysis.