Moorthi,

If you remove the support showing lift off what are the stresses and displacements? If these are acceptable then you don't need to worry about the lift off, except for maybe a phone call from site asking about it during operation.

Removing the support from the Caesar model treats the lift-off condition as a primary/sustained stress. There's always good debate about wether this is a primary or secondary load condition. Treating it as sustained is generally conservative however.

Second, if the support lifts off, more load is transfered to adjacent supports. You may need to check local stresses in the pipe wall from the support. Roarks or FEA works well for this. Span charts don't always consider local stresses.

Sometimes removing the support at the bottom and allowing it to grow down is a good solution to get rid of the lift off issue all together.

Without seeing the whole picture though, none of us can give you a complete answer. I'd recommend reviewing with someone locally to make sure you've covered all of the bases.