Seismic Displacement Design of Earth Retaining Structures

Field performance observations and experimental evidence indicate that well-built retaining structures that are composed of or surrounded by materials that do not lose strength as a result of earthquake shaking perform satisfactorily at moderate levels of ground shaking. Thus, seismic earth pressures need not be considered when the peak ground acceleration is less than or equal to 0.3 g . At higher levels of ground shaking, the seismic evaluation should include the effects of the retained earth. The use of a Mononobe-Okabe-type method requires the selection of the seismic coefficient, which largely determines the magnitude of the seismic load increment. The rational selection of the seismic coefficient requires proper consideration of the seismic hazard at the site and the amount of seismic displacement that defines the threshold between satisfactory and unsatisfactory seismic performance of the earth retaining structure. Thus, a robust seismic design procedure should include a calculation of the potential seismic displacement of the earth retaining structure. In this paper, seismic displacement design procedures for earth retaining structures are examined.