Period Time Range

Question

What is the period time range of first mode of RC high rise buildings under seismic loads?

Seth Guthrie · Answer

In the US there is an approximate period value Ta that gives a decent estimate, but a Moment Frame structure might be significantly longer. 
 
 Staad can, of course, calculate the periods through eigensolution. https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/29023/calculating-modes-and-frequencies