Section 1616.3 of IBC 2003 (it is also in IBC 2006) has an exception that allows you to determine your seismic design category based only on the short-period response acceleration (Table 1616.3(1)) if certain criteria are met. One of the criteria is that your seismic response coefficient, Cs...
I am currently working on a large scale project that involves over 40 new retaining walls. The project is located in an area that is Seismic Performance Category A. When I reference AASHTO (Division 1 - Section 5) regarding the need to consider seismic loading for these retaining walls it...