Seism on buried pipe

Hello

When is generated the buried model, the Caesar II eliminates the weigth, for that reason, is not possible to evaluate the case with seism (g's).

Is there a way for evaluating seism in a buried pipe?

In a buried piping system you're most concerned with the thermal strain. A properly prepared trench will eliminate any weight stress, which is what c2 assumes. The only way to achieve this in a discretized "node/beam element" flexibility program is to zero the densities.

You're correct, with zero mass you can't run dynamics. But think about the situation for a moment: in a seismic event, the pipe will either move with the surrounding soil (i.e. no induced deflections or stresses), or fail in shear (two pieces) across a fault. Why is a flexibility analysis required in this situation: the pipe is either ok, or destroyed - there is no in between?