Proceedings of GeoRisk 2011: Geotechnical Risk Assessment and Management, held in Atlanta, Georgia, June 26¿28, 2011. Sponsored by the Geo-Institute of ASCE. This Geotechnical Special Publication contains 127 peer-reviewed papers that address uncertainties in the geologic environment, covering new and continuing work on geohazard mitigation, uncertainty modeling, and risk assessment and management. Topics include: characterization and modeling of variability of soils across scales; earth structures/slopes; earthquake engineering and soil dynamics; engineering geology and site characterization; geotechnical assessment, characterization, and design for risk management; hazards/risks; limit state design in geotechnical engineering; load and resistance factor design (LRFD) for foundation systems; probabilistic/simulation methods; quantitative risk analysis for embankments, dams, and slopes; retaining structures; risk and reliability in geoenvironmental engineering; uncertainty analysis; and uncertainty modeling. This collection offers researchers and practitioners in all fields of geotechnical engineering essential information on identifying and managing risks.