Hello,
I would like to clarify the following fundamentals. All these are basic and i have no hesitation that sometimes I stuck up even after working in CII for few years.

1. Is there any reference where I can find on how to arrive at the forces at different supports (of course depends on the pipe routing, process conditions etc) without the help of computer analysis. Any paper or examples from books would help. I often see some very senior guys who can appropriately (almost 90% of the time) finalize the supports or suggest the pipe routing by calculating the movements (which of course I can do as well) and force values.
2. How the support stiffness affect the calculation? And how to arrive at the stiffness value; F=Kx?
3. How does the seismic 'g' affect the stress calc? We often see providing additional restraint (guides, line stops) help in reducing the seismic stress values, but I would like to know how does those function? Same as wind...

Apologize for the long post.The intent is like many of us who started the career with software sometimes stuck with the first principles. Any help in this matter will be appreciated