The paper demonstrates that whereas often in seismic geotechnical design it is not realistically feasible to design with ample factor of safety against failure as is done in static design, an "engineering" apparent seismic factor of safety less than 1 does not imply failure. Examples from slope stability and foundation rocking illustrate the concept. It is also shown that in many cases it may be beneficial to under-design the foundation by accepting substantial uplifting and/or full mobilization of bearing capacity failure mechanisms.
NOTICE: this is the author’s version of a work that was accepted for publication in Soil Dynamics and Earthquake Engineering. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Soil Dynamics and Earthquake Engineering, [VOL 57, (February 2014)] DOI10.1016/j.soildyn.2013.10.002 Licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.