IBC Seismic Retaining Wall Design 1

[cap4000]

Does anyone know how to relate Kh earthquake in terms of gravity values to the IBC2000 Section 1615.2 with regard to designing retaining walls. AASHTO 1996 uses Am =(1.45-A)A which looks pretty simple if you have the AASHTO maps. IBC uses deterministic and probilistic limits with way to many formulas. Soft soils leads to dynamic amplification effects which complicates things even further. Any feedback will be appreciated.

 

[mrengineer]

Not sure if this is what you need, but FEMA 369, Part 2 (Commentary), 7.5.1 shows Kh = S(subDS)/2.5. You can calculate S(subDS) from IBC.
(Google FEMA 369).