Selection of Physical 2D Probabilistic Realizations of Shear Wave Velocity Random Field Based on Dispersion Curves Derived from MASW Numerical Experiment

摘要

Soil spatial variability is modeled using random fields (RF) theory. Discretization based on series expansion methods is generally adopted to evaluate the RF of a soil property. Several realizations are generated randomly to represent the statistical distribution of the soil parameter. However, not all of them represent the real variability. Thus, this paper suggests a numerical methodology to select the physical shear wave velocity (Vs) RF realizations. Vs RF is discretized using EOLE method. In order to determine the dispersion curve (DC) of a heterogeneous soil, the MASW experiment is modeled using FLAC~(2D) software. DCs are compared to the DC of the mean homogeneous deterministic model. All curves, located outside the range of ±3 standard deviation of the mean curve, are rejected and the realization is nonphysical. Consequently, the significant variation of soil properties produces a non-negligible number of nonphysical realizations and a high variability in the FK spectral maxima and the DC.