The timing of liquefaction and its utility in liquefaction hazard evaluation

The behavior of liquefiable soils, and of soil deposits containing liquefiable soils, can change dramatically upon triggering of liquefaction. This suggests that knowledge of the timing of liquefaction, e.g., whether it occurs early or late in a particular ground motion, would be useful in predicting the potential effects of liquefaction. The relatively recent availability of strong motion records from instruments underlain by liquefiable soils provides a new type of case history - one in which the ground motion intensity at the time of triggering can be identified. The paper reviews procedures for identification of the time of triggering, and shows how that time can be used to judge the relative performance of empirical triggering models. It also introduces a framework for the use of timing information in the development of improved procedures for evaluation of the effects of liquefaction. (C) 2016 Elsevier Ltd. All rights reserved.