Incorporation of three different creep models into large-strain consolidation analysis of a clayey tailings deposit

Abstract

Soft soils and clayey tailings deposits can exhibit substantial creep during consolidation. Creep can strongly influence the consolidation and strength development of tailings deposits but is rarely considered in existing large-strain consolidation analyses for design purposes. This paper presents an analysis of a 13 m high deposit of soft clayey tailings using large-strain consolidation coupled with three alternate creep formulations: the Yin–Graham, Vermeer, and overstress formulations. Predictions of settlement and excess pore water pressure using all three consolidation–creep models have better agreement with the measured data compared to predictions from a large-strain consolidation model without creep. The overstress model is more difficult to calibrate for young soft soils in an initially normally consolidated state, owing to the strong dependency on the initial ratio between an unknown small preconsolidation stress and the initial small effective stress. The models calibrated to the pilot study were then used to extrapolate the full-deposit behavior, and the implications of using such consolidation–creep models and their limitations are discussed.