ibc 2000 seismic question

huangyhg

ibc 2000 seismic question
does section 1622.4.8 require seismic design for burried structures in all categories, or just categories 2 and 3?  is the intent of this section to include lateral earth pressures from earthquake?  my interpretation for consideration of lateral earth pressure from seismic is that it is only a consideration if you are in seismic design category d or worse, according to sections 1802.2.6 and 1802.2.7 of the ibc 2000.
my state (ny) didn't require seismic design until it adopted (and tweaked) the ibc 2000 in 2003, and i find it sometimes hard to figure out what the code is requireing for seismic design.