Earthquake safety evaluation of sanitary landfills

Earthquake ground motions at municipal solid waste landfills must be specified according to the level of hazard or criticality of the site along with the type of engineering analysis that is to be performed. Todayʹs landfills, when built to regulatory standards, are unlikely to be critical, but older landfills can be seriously hazardous. Consequently, the hazards are graded as: (1) none to negligible; (2) low; (3) moderate; and (4) great. For non-critical sites, motions may be obtained from a probabilistic map but a deterministic map, if available, is preferred as part of a non-sites-pecific investigation; however, for critical sites, a deterministic, site-specific evaluation should be made. Motions must be specified appropriately for the type of analysis, whether it is for foundation liquefaction, stability of slopes, integrity of barriers, earth pressures, or the design of appurtenant structures.