Numerical Analyses for the Investigation of Soil Improvement Methods in Settlement Issues of Spoil Materials from Lignite Mines

The response of a massive heap from lignite mines' spoils is being investigated when used as a foundation soil for a typical embankment. Due to the high compressibility of the spoil material and in order to limit large settlements, the effects of three soil improvement methods were analyzed: dynamic compaction, stone columns, and deep soil mixing using fly ash. The settlements were analyzed using 2D finite elements under plane strain conditions and assuming dry conditions. Two constitutive models were employed, the Mohr-Coulomb and the Hardening Soil.