permitted analytical procedures for concrete buildings 2 s

huangyhg

permitted analytical procedures for concrete buildings > 2 s
table 12.6-1 of asce7-05 states that the equivalent lateral force procedure is permitted for certain structural characteristics.  would the equivalent lateral procedure be applicable to a 3 story concrete building? i am confused by "regular structures w/ t < 3.5s and all structures with light framed construction".  if i have a 3 story concrete building w/ t < 3.5s, can i use the equivalent lateral procedure?  if not, what is the code's reasoning behind requiring a more detailed analysis for those buildings.  thanks.
"regular structure" refers to the definition of "regular" vs. "irregular" defined in section 12.3 (see tables 12.3-1 and 12.3-2)

if you have a concrete building with a period greater than 3.5s, i'd say you had some major issues with the analysis.  elp would be applicable 99% of the time for a 3-story concrete building.