Dears,
1) Definitely there was an occasional impact load which threw the pipe off the supports. That force is unknown as operations did not report any upset in the operation of this line.
2) Line is safe as far as its operating and design conditions are concerned.
3) I modeled these dislocations as "Axial displacement" at one node in the pipe and by giving gap in +Y support (Not equal to shoe height as before resting on supports, it would compress the cladding/insulation.)
4) It would be interesting to know how to model the load on beams now as the line is definitely "trying" to restore to its "pre-occasional load" conditions and beams are resisting it.
Any idea?