Evaluation of Liquefaction Probability of Earth-Fill Dam over Next 50 Years Using Geostatistical Method Based on CPTU

In this paper, the spatial distribution of the liquefaction probability inside the studied dam was calculated from CPTUs including conversion errors and the spatial variability of the soil parameters. In addition, based on the seismic hazard at the studied site and the fragility, the spatial average of the liquefaction probability over the next 50 years was evaluated. Although the CPTU is often preferable for identifying the liquefaction probability, the CPTU is still not widely used in Japan. Therefore, the focus will be placed here on the SPT N-value and the fines content, Fc, because the majority of the accumulated site characterization data in Japan consists of SPT N-values and Fc. Utilizing the conditional simulation, the spatial distribution of the expected values for Fc and NSPT inside the dam was calculated with high spatial resolution. Based on the results of the simulation the scale of the weak areas and the spatial continuity of the soil profile of the dam were clarified.