Determination of Liquefaction in Time Domain Using Shake Table Test, Wavelet Analysis and Numerical Approach-Paper

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The study investigates earthquake-induced liquefaction in saturated Kasai River sand using shake-table experiments, wavelet analysis, and numerical simulation. Dry and saturated sand models were shaken with 10 sinusoidal cycles at 0.35g and 2 Hz. Pore-pressure transducers and accelerometers monitored the soil response.<br /><br />In the saturated tests, excess pore pressure developed first near the surface and progressed downward. Liquefaction occurred after roughly 6–8 cycles (3–4 seconds), with deeper soil liquefying later and taking longer to dissipate excess pressure. Dry sand did not show the same response.<br /><br />Wavelet analysis of the acceleration records identified a reduction in wave amplitude at about 2.8 seconds, interpreted as the onset of liquefaction. This agrees closely with the experimental pore-pressure observations. The authors also modeled the tests in FLAC2D using the Finn model to simulate pore-pressure generation and soil behavior. The numerical results predicted liquefaction at shallower depths before deeper ones, consistent with the experiments.<br /><br />Overall, the study finds that wavelet analysis can help detect liquefaction in the time domain, while the FLAC2D simulations reproduce the observed progression of liquefaction reasonably well. Together, the experimental, signal-analysis, and numerical results indicate that Kasai River sand is susceptible to liquefaction under the tested shaking conditions.

Keywords

earthquake-induced liquefaction

Kasai River sand

shake-table experiments

saturated sand

excess pore pressure

wavelet analysis

accelerometer records

FLAC2D simulation

Finn model

soil liquefaction onset