Hi i'm working for the project considering seismic anchor displacement of structure.
As normal practice, i usually used a snubber as a special item for seismic case.
but using a snubber in this project makes bigger displacement due to operating movement.
(According to CAESAR instruction, OPE movement is inputted at snubber point)

LOAD CASE : W+P1+T1+D1+D2+U1

D1 : OPE movement (+x : 50mm)
D2 : Seismic anchor displacement(+x : 50mm)

100mm for +x dir. is shown on the result.

This means that a snubber has a bad influence on seismic anchor displacement.
Because a snubber is installed on structure, Is structure movement not eliminated?

I know this is my mistake. Anyone knows a effective method to eliminate seismic anchor displacement?

i have trouble checking a pump nozzle load with an above load case.

thank you.

Structural stiffness is really difficult to deal with, it will add more movement to the piping system if your support is connected to that structure that gives high deflection. In my own opinion, the snubber may not absorbed the SAM since this is a movement from shock load and not thermal. You cannot eliminate seismic anchor movement, they are given and added to the restraint node. Think of a support location with a minimal or negligible movement with respect to pump anchor point, the large difference of displacement created by the structure movement creates forces and moments on the pump. Eliminating the siesmic anchor displacement on the structure is not connecting or isolating the support form that structure.