The Inversion of One-Dimensional Soil Parameters in the Frequency Domain With Considering Multilayered Earth Based on Simulated Annealing Algorithm

A method to study the soil parameters’ frequency dependence of horizontally multilayered earth is developed. It is achieved by multifrequency inversion. Apparent resistivity can be obtained from the potential difference and the injecting current. Since the inversion is performed simultaneously at multiple frequencies and the inversion at each studied frequency is independent, parallel computing can be used to improve the efficiency of the inversion algorithm. The inverse problem in this study is an unconstrained optimization problem. So one of the central issues is the optimization of model parameters. Simulated annealing algorithm adopted in this study is an effective method to solve this kind of problem. The difference between the two calculation results based on the dynamic state field theory and quasi-static field theory is studied. The proposed method is validated by the interpretation of measurement data. The frequency dependence of soil parameters is studied by applying the method to interpret spectral-induced polarization data.