Numerical modeling of liquefaction and comparison with centrifuge tests

TLDR

Liquefaction prediction and mitigation are critical for seismic regions, yet conventional methods often estimate triggering at depths >50 m, while field evidence shows most liquefaction occurs below ~15 m, making deep remediation costly. The study evaluates centrifuge test results using an effective‑stress numerical modeling procedure. The authors apply this effective‑stress model to assess the centrifuge experiments. The study finds that incomplete saturation and densification at depth caused by high‑acceleration fields explain the apparent depth limitation of liquefaction in centrifuge tests, implying that such limitations could reduce remediation costs. Keywords: liquefaction, dynamic centrifuge modeling, numerical modeling, depth limitation.

Abstract

The prediction of liquefaction and resulting displacements is a major concern for earth structures located in regions of moderate to high seismicity. Conventional procedures used to assess liquefaction commonly predict the triggering of liquefaction to depths of 50 m or more. Remediation to prevent or curtail liquefaction at these depths can be very expensive. Field experience during past earthquakes indicates that liquefaction has mainly occurred at depths less than about 15 m, and some recent dynamic centrifuge model testing initially appeared to confirm a depth or confining-stress limitation on the occurrence of liquefaction. Such a limitation on liquefaction could greatly reduce remediation costs. In this paper an effective stress numerical modeling procedure is used to assess these centrifuge tests. The results indicate that a lack of complete saturation and densification at depth arising from the application of the high-acceleration field are largely responsible for the apparent limitation on liquefaction at depth observed in some centrifuge tests.Key words: liquefaction, dynamic centrifuge modeling, numerical modeling, depth limitation.