Hi,

I am trying to develop an as-built model where pipe has displaced. I am trying to check the integrity of the piping in the displaced condition. I am attaching the hand sketch of how the layout and support is as built.

For instance, in the sketch lets consider S3, S4 and S5 has displaced towards east. Which means my pipe shoe has fallen from the base structural steel.

Case 1:- I know how much my pipe has displaced in vertical and horizontal directions. Should I model pipe support with Cnode and enter the displacements. In this case if the node displacement is 150mm, CNODE with 150mm disp input is considering a restraint and giving me restraint report. This is actually not true as there is no restraint at that particular location (pipe has displaced and pipe shoe has fallen from steel).

Case 2:- I know the restraints are not active and I am removing the support from all the locations where pipe supports are not in place with steel. We all know this scenario is also not true, as I am removing the restraints it leaves me with large unsupported pipe span. Hence more sustained stresses and Sags. I am confident case 2 is not possible. Is my case 1 more realistic approach?

I have more questions added to this model. Since my pipe has displaced it means the displacement is present in sustained condition itself. Should I have to build my sus load case with D1. In such case if I am building W+P+D for sustained and W+P+T+D for op case, when I am calculating exp stresses the effect of imposed displacement is not being calculated and stresses are in safe zone. But the other way round, If i consider D either in sustained or in ope case, the expansion stresses are above limit. I want to understand how to build a more realistic model. Kindly help me.