A probability-based efficient assessment of seismic wave scattering in complex topography with geo-property uncertainty

Abstract

There is great randomness in determining geotechnical parameters, resulting in an uncertain local site effect caused by seismic wave scattering such as valleys, hills, basins, etc. It is significant to develop the probability-based assessment method to quantify the local site effect considering the geo-property uncertainty. The multiplicative dimensional reduction method (M-DRM) is employed to approximate statistical moments of the response of the local topography with random parameters. A multi-dimensional random problem is converted into a series of deterministic analyses, solved by the boundary element method. The probability distribution estimation can be obtained based on the maximum entropy algorithm. This approach is used to solve the seismic wave scattering of fossil river courses under P-waves, and the applicability is verified compared to the Monte Carlo simulation. The results show that M-DRM can assess the seismic wave scattering by local topography with high efficiency. The seismic wave scattering inhomogeneously magnifies the geo-property uncertainty in wave propagation. The displacement variability is primarily related to the incident frequency, and the response under high-frequency P-waves has significant variability. It is the reason that the effect of the geo-property uncertainty on the peak ground acceleration is determined by the energy distribution of the incident wave.