UNDRAINED STABILITY ANALYSIS METHODS FOR HIGH EARTH-FILLS ON SATURATED SOILS

For the stability problem of rapid earth-fills on saturated soils, especially for high earth-fills, it is necessary to perform an undrained stability analysis because the excess pore water pressure in foundation soils cannot dissipate in time. There is still a lack of the broad consensus on the selection of undrained strength parameters and analysis methods in Chinses geotechnical engineering society, and there are also engineering failure cases reported. Therefore, this paper systematically compared three undrained stability analysis methods and their strength parameters used worldwide. The finite element limit analysis based on undrained stability calculations was performed for two simple examples and a practical engineering case. The results highlighted that it is necessary to use the undrained analysis method using the Mohr-Coulomb effective stress strength parameters (Method A) or the undrained strength parameters (Method B) for this problem. The conventional stability analysis using the Mohr-Coulomb total stress strength parameters (Method C) mostly overestimates the factor of safety of earth-fills on saturated foundation soils.