Energy-Based Liquefaction Potential Evaluation Recommended in Practical Design

Abstract

It is widely recognized that liquefaction behavior is more closely correlated to dissipated energy than to applied stress, and hence Energy-Based Method (EBM) for liquefaction evaluation seems promising though Stress-Based Method (SBM) is exclusively used worldwide.　With this background, a research committee on EBM for liquefaction was held in the Japanese Geotechnical Society probably as a first endeavor in the world.　In this article, as the first paper in a special volume edited by the committee, a perspective on energy-based liquefaction interpretations is summarized based on the committee report together with a personal view of the author.　Among the major findings, test results on various intact soils sampled in situ demonstrate that cumulative dissipated energy can uniquely determine pore-pressure buildup and induced strain regardless of cyclic loading histories, and correlate with CRR in SBM uniquely again irrespective of soil properties.　Liquefaction evaluations are implemented for a hypothetical uniform sand layer as well as two case history soil layers by employing three different EBMs available in Japan wherein the cumulative dissipated energy is compared with earthquake wave energy at each soil layer.　The comparative study reveals in general that the EBM can predict liquefaction behavior without worrying about the variability of earthquake waves unlike the SBM, though there still remain differences in the evaluations among the three EBMs to be studied further.　Considering the great advantage of EBM over SBM, it is strongly recommended to be employed in engineering practice.