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Positive and negative persistent photoconductivity in a two-side-doped In0.53Ga0.47As/In0.52Al0.48As quantum well

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Probabilistic assessment of liquefaction initiation hazard

This paper presents the results to date of ongoing studies to develop improved, probabilistically-based correlations for the use of SPT data for evaluation of resistance to "triggering" or initiation of cyclic liquefaction. Although these studies are ongoing, the relationships developed at this stage are considered to represent a sufficient advance over previously available, similar relationships as to merit their exposition at this time. The relationships presented herein have a number of significant advantages over previous probabilistic and "deterministic" relationships currently available. These include: • Previously available field case history data have been re-evaluated, taking advantage of recent developments/insights regarding (a) factors affecting "correction" of SPT data for energy, equipment, procedure, and rod-length effects, and (b) factors affecting evaluation of in-situ equivalent uniform cyclic stress ratio including source mechanism effects, local site effects, etc. • A large number of "new" field case history data were collected and similarly evaluated. • With this greatly enhanced database, higher standards were set for acceptability of case history data, and data not meeting these standards were deleted. The result is an enlarged database of high quality. • The Bayesian parameter estimation method was used to develop and evaluate correlations. This method allowed for separate treatment of different sources of aleatory and epistemic uncertainty, and allowed assessment of more contributing variables/parameters than prior studies. The resulting correlations provide a significantly improved basis for evaluation of liquefaction resistance, and also resolve a number of previously difficult issues including (a) "corrections" for fines content and effective overburden stress, and (b) magnitude-correlated duration weighting factors (for magnitudes other than M W = 7.5

Buchanan\u27s seeds for 1931 /

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Buchanan\u27s seeds for 1932 /

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