Buried pipe modeling and uniform loads

Hi,
When I use the underground pipe modeler, all densities on buried elements are zeroed.
What happend with the uniform loads in G's?
I'm using the uniform loads to represent the sismic forces in the system, and if the desities are zeroed also this loads are zeroed.
Can anyone help me with this topic?

Thanks
R.Kühn

When you analyze buried pipe, you are simulating a "beam on a continuous elastic foundation". As such, there should be no weight induced stresses. This is why CAESAR II resets all the densities to zero (in the Buried Pipe Modeler).

If you need to reset the density for dynamic analysis purposes, you can do so in the buried model (not your original model).