Section 1807—Foundation walls, retaining walls and embedded posts and poles.
1807.2.2 Design lateral soil loads. Retaining walls shall be designed for the lateral soil loads set forth in Section 1610. For structures assigned to Seismic Design Category D, E, or F, the design of retaining walls supporting more than 6 feet (1829 mm) of backfill height measured to the bottom of the footing shall incorporate the additional seismic lateral earth pressure in accordance with the geotechnical investigation where required in Section 1803.2.
[Statutory Authority: RCW 19.27.031
. WSR 20-01-090, § 51-50-1807, filed 12/12/19, effective 7/1/20.]