Enhanced data interpretation: combining in-situ test data by Bayesian updating

Combining data sets obtained during site characterization studies has the potential to enhance data interpretation. An example is provided where seismic data is combined with preconsolidation pressures obtained from laboratory tests. Semi-empirical relationships between preconsolidation pressure and shear wave velocity can be used to estimate the preconsolidation pressure. Conventionally, the uncertainties in the relationships are ignored. The Bayesian updating approach is used to take these uncertainties into account. Both trend analysis and kriging interpolation are used for the laboratory tests on the preconsolidation pressure to derive the prior distributions. The posterior preconsolidation pressures are then obtained by incorporating shear wave velocity measurements from a seismic dilatometer test. The analyses demonstrate that the seismic dilatometer data can be enhanced by the laboratory data set. This approach can be extended to enhance two-dimensional geophysical surveys by conditioning on a small number of accurate laboratory or in-situ test measurements.