Site Factors

See FHWA-HRT-06-032, Seismic Retrofitting Manual for Highway Structures, Part 1-Bridges, Jan 2006.

a. Fa is determined by the site class and the short-period spectral acceleration (Ss) for the upper level earthquake.

b. Fv is determined by the site class and the long-period spectral acceleration (S1) for the upper level earthquake.