Effect of Randomness of Parameters on Amplification of Ground Motion in Saturated Sedimentary Valley

Featured Application Considering the randomness of saturated media parameters such as porosity and permeability coefficient and the randomness of geometric boundary, based on Biot's theory and the indirect boundary element method (IBEM), in this paper, the Monte Carlo method is used to analyze the stochastic amplification of ground motion in a saturated sedimentary valley. The stochastic seismic response law of a saturated complex site is obtained, which is useful in engineering. Based on Biot's theory and the indirect boundary element method (IBEM), the Monte Carlo method is utilized to generate random samples to calculate the displacement response of a saturated sedimentary valley under SV wave incidence. The purpose of this paper is to explore the effects of randomness of porosity, permeability coefficient, and geometric shape on the seismic amplification effect of saturated complex sites. It is shown that the change of media porosity in the saturated site with defined boundary has relatively little influence on the ground motion, and the influence of the permeability coefficient is slightly larger. While in the site with a random boundary, the influence of both the porosity and permeability coefficient are significant, which cannot be ignored. The conclusion plays an important guiding role in earthquake disaster prevention and mitigation, such as seismic risk analysis and earthquake microzonation in saturated sedimentary valleys.