Some one asked me abt dynamic analysis and when we need to perform dynamic analysis and what about seismic irregularities and how to base our design on that. I couldnt reply but right now there is power shut down in my office (im enjoying it). So thought to share the reply on sepakistan.com so its openly available for everyone. I took snap shopts from my mobile. This document is the seismic symmary from SK gosh. Then there r some pages abt irregularities from my fav book abt tall structures. I think these pics speak more than i know. So have a look at them.