Seismic design considerations for gravity retaining structures

Major earthquakes have been observed to damage marginal wharf gravity retaining structures or walls throughout the world, and earthquakes of similar magnitude occur quite often in Canada. These earthquakes generally take place in the British Columbia coastal areas, the St. Lawrence Valley, Baffin Island, and the Yukon Territory. Elsewhere, normally designed marginal retaining structures should have adequate factors of safety to withstand anticipated seismic loads. However, in earthquake-prone areas it is recommended that most marginal retaining structures be designed using the seismic coefficient method. While not all aspects of the suggested seismic design procedure are developed, detail is provided on seismic exposure at the site, earth pressures due to earthquake conditions, and recommended factors of safety for short-term conditions. Design aspects of a more specific geotechnical nature (soils investigation, liquefaction, remedial measures, tsunamis, and backfill specifications) are indicated.