SIMPLIFIED SEISMIC DESIGN PROCEDURE FOR GEOSYNTHETIC-LINED, SOLID-WASTE LANDFILLS

This paper critically reviews seismic design practices in light of the observed performance of landfills during recent earthquakes. Developm ents in these areas are summarized as follows: earthquake ground motio ns, dynamic waste fill properties, dynamic responses of geomembranes a nd their interfaces, nonlinear dynamic response analysis, and seismic stability evaluation. A newly developed simplified seismic analysis pr ocedure that requires the most critical factors be addressed during a seismic performance evaluation is presented. The underlying seismic an alysis procedure has been validated against observed performance of la ndfills shaken by the 1989 Loma Prieta and 1994 Northridge, California earthquakes. The procedure is comprehensive in that it requires: (i) characterization of the design bedrock motions in terms of intensity, frequency content, and duration; (ii) estimation of the seismic loadin g at the base and cover of the landfill; (iii) evaluation of performan ce in terms of seismically induced permanent deformations; and (iv) ap propriate engineering judgment.