قارن الطرق

	Seismic Hazard Deaggregation	Liquefaction Triggering Analysis
المجال	Disaster Studies	Disaster Studies
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1999	2001
صاحب الطريقة	Paolo Bazzurro & C. Allin Cornell	H. B. Seed & I. M. Idriss (original 1971 procedure); T. L. Youd & I. M. Idriss (NCEER consensus update)
النوع	Post-processing pipeline that decomposes probabilistic hazard into contributing scenarios	Stress-based deterministic triggering pipeline
المصدر التأسيسي	Bazzurro, P., & Cornell, C. A. (1999). Disaggregation of Seismic Hazard. Bulletin of the Seismological Society of America, 89(2), 501-520.	Youd, T. L., & Idriss, I. M. (2001). Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils. Journal of Geotechnical and Geoenvironmental Engineering, 127(4), 297-313.
الأسماء البديلة	Seismic Hazard Disaggregation, PSHA Disaggregation, Hazard Deaggregation, Controlling Earthquake Deaggregation	Simplified Liquefaction Procedure, Seed-Idriss Simplified Procedure, CSR-CRR Liquefaction Analysis, Liquefaction Factor-of-Safety Analysis
ذات صلة	3	3
الملخص	Seismic hazard deaggregation (also spelled disaggregation) is the post-processing step that opens up a probabilistic seismic hazard result to reveal which earthquakes actually drive it. A probabilistic seismic hazard analysis (PSHA) integrates over all magnitudes, distances, and ground-motion variability to return a single mean rate at which a ground-motion level is exceeded, but in doing so it loses sight of the individual scenarios. Bazzurro and Cornell's 1999 paper formalized how to invert this aggregation, expressing the contribution to the exceedance rate as a probability distribution over magnitude, distance, and epsilon — the number of standard deviations a target motion sits above the median prediction. The result identifies the controlling earthquake: the magnitude-distance-epsilon combination most responsible for the hazard at a chosen return period. This deaggregation is what lets engineers select realistic scenario earthquakes and ground-motion records for design and analysis. It bridges the probabilistic and deterministic worlds by naming the events hidden inside the integral.	Liquefaction triggering analysis evaluates whether saturated, loose granular soils will lose strength and behave like a fluid during earthquake shaking, using the simplified stress-based procedure that has anchored geotechnical earthquake engineering since Seed and Idriss introduced it in 1971. The method compares demand against capacity: the cyclic stress ratio (CSR) imposed by the earthquake versus the cyclic resistance ratio (CRR) the soil can sustain, both expressed as ratios of cyclic shear stress to effective overburden stress. Capacity is read from in-situ penetration tests — standard penetration test blow counts or cone penetration test tip resistance — through empirical curves calibrated on field case histories of sites that did and did not liquefy. The Youd and Idriss 2001 NCEER consensus report standardized these curves and the correction factors, and Idriss and Boulanger's 2008 monograph refined them. The ratio of resistance to demand gives a factor of safety against triggering at each depth. It is the workhorse first-order screen for liquefaction in routine practice worldwide.