I am getting stresses exceeding code limits because of earthquake loading in my model. The model is B31.1 piping in a V-shape with some branched piping near each end. One arm of the V is shown to displace up to 27" at its end and creates excessive bending stresses at the bend.

Is there anyway to account for lateral hanger support? The supports we are using are Anchor clevis hangers. There are about 10 hangers in that arm. If the pipe actually displaces 27", the hanger in real life would either resist that movement or be broken off, but I can't find any resources to determine which.