Seismic Response Analysis of Cut-Off Wall of Dam Foundation Under Spatial Variability of Parameters

Abstract

The overburden of rockfill dams has complex soil types, loose structures, and sometimes lenses, which make the material parameters of the overburden have spatial variability, and the impact of earthquakes on the stress and deformation of the dam foundation cut-off wall cannot be ignored. Under the framework of Monte Carlo, by using the Gaussian spatial random field discrete method of Cholesky decomposition, the secondary development of Abaqus with Python is used to realize the “non-invasive” stochastic finite element analysis of the spatial variability of the overburden material. The research results show that considering the spatial variability of the cover material, the stress and deformation of the different parts of the cut-off wall have different degrees of excess, and the coefficient of variation of dynamic stress is greater than that of the dynamic displacement, indicating the variability of the material parameters of the cover is more sensitive to the stress changes of the impervious wall under the action of earthquake. Therefore, this uncertainty should be considered in the design stage to ensure the safe operation of the dam foundation impervious wall.

Keywords

• overburden
• cut-off wall
• spatial variability
• stochastic finite element
• seismic response