Seismic responses of an asphalt concrete core wall dam considering the spatial variability of overlay foundation materials

The uncertainty of the parameters of the overburden soil layer often significantly affects the seismic responses of a dam with asphalt concrete core. The spatial random field simulation technology was combinedly used with the finite element method, a according to the sensitivity analysis results of a dynamic equivalent linear model, dynamic random parameters were selected, the spatial variability of covering material parameters was considered by using normal or lognormal distribution functions, the Gaussian autocorrelation function was used to consider the spatial correlation, the random parameter library was generated by the covariance decomposition of Python, and the secondary development of scripts for ABAQUS was carried out. On these bases, by using the Monte Carlo method, the random field simulation of spatial correlation and discrepancy of covering materials and the "non-invasive" stochastic finite element analysis were realized. Taking a practical project as an example, the cases of random static parameters, random dynamic parameters and random static and dynamic parameters of overburden materials were considered respectively. The statistical analysis and probability distribution test for the mean value, coefficient of variation and 95% confidence interval limit of the horizontal peak acceleration at the asphalt concrete core dam crest and core crest and of the vertical permanent deformation of the dam body were conducted. The results show that: considering the random probability of overburden material parameters will increase the seismic response of the dam body; considering the random static and dynamic parameters, the difference between the seismic response and the determined value is the largest; the statistical results of seismic response of the dam body do not necessarily conform to normal or lognormal distribution; the influence of spatial discrepancy of overburden material on the peak acceleration is greater than that on the permanent deformation; the dispersion degree of seismic response results of the overburden layer is larger than that of the dam body and core wall. © 2022, Editorial Office of Journal of Vibration and Shock. All right reserved.