LIQUEFACTION CRITERIA BASED ON STATISTICAL AND PROBABILISTIC ANALYSES

Probabilistic procedures for evaluating liquefaction resistance have the advantage of allowing an acceptable level of risk to be specified by the user. Liao and his colleagues used a logistic procedure to develop probabilistic cyclic resistance ratio (CCR) curves. The original Seed and Idriss magnitude scaling factors, however, were used to correct for magnitude. Youd and Noble (herein) use the logistic procedure to analyze liquefaction resistance with a magnitude added as an independent variable. New case history data and (N sub 1)sub 60cs (corrected for fines content) were added to enlarge the case history data set. Primary conclusions from the study are: The probabilistic procedure allows direct incorporation of an appropriate probability, or risk factor in liquefaction hazard analyses. The procedure also provides a more scientifically rigorous method of analysis of the data than the hand-shaped curves used in the simplified procedure. The analyses by Liao and his colleagues indicate, for clean sands, that the standard criteria from the simplified procedure provide a probability of occurrence of about 20% for corrected blow counts (N sub 1)sub 60 between 11 and 28. Below an (N sub 1)sub 60 of 11, the original simplified base curve is characterized by a probability of liquefaction smaller than 20%. Above an (N sub 1)sub 60 of 28, the curves of Liao et al. indicate a probability of liquefaction greater than 20%. The curves in the upper par of the range, however, are near the limit of liquefaction occurrences and are not well constrained by empirical data. The analyses by Youd and Noble include magnitude as an independent variable eliminating the need for magnitude scaling factors in the analysis. The Youd and Noble results are more conservative than those of Liao et al. for (N sub 1)sub 60cs less than 20 and characterize the simplified base curve by probabilities ranging from 20% to 50%.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/10883800
• Corporate Authors:

  National Center for Earthquake Engineering Research

  State University of New York, Buffalo, Red Jacket Quadrangle, Box 610025
  Buffalo, NY  United States  14261-0025

  Brigham Young University

  Department of Civil and Environmental Engineering
  Provo, UT  United States  84602
• Authors:
  • Youd, T L
  • Noble, S K
• Conference:
  • NCEER Workshop on Evaluation of Liquefaction Resistance of Soils
  • Location: Salt Lake City, Utah
  • Date: 1996-1-5 to 1996-1-6
• Publication Date: 1997-12-31

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 201-216
• Serial:
  • National Center for Earthquake Engineering Research
  • Publisher: National Center for Earthquake Engineering Research
  • ISSN: 1088-3800

Subject/Index Terms

• TRT Terms: Earthquakes; Fines (Materials); Hazard analysis; Liquefaction; Logistics; Magnitude; Probability; Resistance (Mechanics); Statistical analysis
• Subject Areas: Data and Information Technology; Freight Transportation; Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 00758970
• Record Type: Publication
• Report/Paper Numbers: Technical Report NCEER-97, -0022
• Files: TRIS
• Created Date: Jan 28 1999 12:00AM