Pipelink is quite rudimentary. It does not provide the ability to assign guide supports to different nodes. For example, horizontal loads need to be applied to Vertical Members, while vertical loads need to be applied to Horizontal Members. The same would be true for pipe Anchors. It is inaccurate to apply all the loads to a single node.
Additionally, AutoPIPE Nonlinear analysis generates a significant number of primary loadcases, and STAAD should have a way of developing ASCE Load combinations using all the loads directly from AutoPIPE.
Per your suggestion, if we defined releases on the sliding base plates, how would we capture the shear effect of friction?
Thank you for posting this idea. However, there are two suggestions which would be better posted as separate ideas so that the true value of each can be identified from supporting votes. Your idea is basically to have a new object added to STAAD to represent a special type of connection arrangement. I would say that you would be better explicitly defining this connection using three dummy members which have the load transfer mechanics defined in their end releases. Then your piping connection is made to the pipe connection point. E.g. the dummy member that is below the pipe point is defined with FY and FZ releases to prevent shear transfer. Then the lateral beams are also given FY and Z releases, but as horizontal members, they wont transfer vertical forces. Basically, create the connectivity as structural objects.