Σύγκριση μεθόδων

	Liquefaction Triggering Analysis	Deterministic Seismic Hazard Analysis
Πεδίο	Disaster Studies	Disaster Studies
Οικογένεια	Process / pipeline	Process / pipeline
Έτος προέλευσης	2001	1990
Δημιουργός	H. B. Seed & I. M. Idriss (original 1971 procedure); T. L. Youd & I. M. Idriss (NCEER consensus update)	Leon Reiter (codification); classical engineering-seismology practice
Τύπος	Stress-based deterministic triggering pipeline	Scenario-based ground-motion estimation pipeline
Θεμελιώδης πηγή	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.	Reiter, L. (1990). Earthquake Hazard Analysis: Issues and Insights. New York: Columbia University Press. ISBN: 9780231065344
Εναλλακτικές ονομασίες	Simplified Liquefaction Procedure, Seed-Idriss Simplified Procedure, CSR-CRR Liquefaction Analysis, Liquefaction Factor-of-Safety Analysis	DSHA, Scenario Earthquake Analysis, Maximum Credible Earthquake Analysis, Deterministic Ground-Motion Estimation
Συναφείς	3	3
Σύνοψη	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.	Deterministic Seismic Hazard Analysis (DSHA) estimates the ground motion a site would experience from a specific, postulated earthquake scenario rather than from the full probabilistic aggregation of all possible earthquakes. The analyst identifies the seismic sources capable of affecting the site, assigns each a maximum magnitude and a closest distance, and then asks what shaking the most demanding of these scenarios would produce. Leon Reiter's 1990 text codified the four-step DSHA procedure that remains the textbook reference, situating it alongside the probabilistic framework that Cornell introduced in 1968. The output is typically a single design ground motion or response spectrum, often computed at the median or median-plus-one-standard-deviation level. DSHA answers the question 'what is the worst shaking a credible earthquake could deliver here?' rather than 'how often is a given shaking level exceeded?'. It remains central to critical-facility design, scenario emergency planning, and as a deterministic cap on probabilistic results.