Consider the following hints and recommendations when performing a similar type of analysis:
Set contact parameters properly. Ensure that contact pairs are always bonded. If not done correctly, contact may be lost causing rigid-body motion to occur.
When using element birth and death (EALIVE and EKILL, respectively), enable large-displacement geometry (NLGEOM,ON).
Use the unsymmetrical Newton-Raphson solution method (NROPT,UNSYM) with the coupled pore-pressure-thermal mechanical elements (CPT212 in this problem).
Ignore the contact-element status warning that may appear at the start of the geostatic solution. (Abrupt status changes are expected, as the contact elements are being deactivated and then reactivated.)