Modelling the time-dependent compression of peat and organic soils: Modélisation le compactage temps-dépendant de la tourbe et des sols organiques

Creep (or secondary) settlement is well known to contribute significantly to the overall settlement of peats and organic soils. A number of constitutive models to predict one-dimensional creep behaviour have been proposed and have had mixed success. This paper examines the potential of the elastic visco-plastic model proposed by Yin and Graham (1996), and the C_α/C_c approach (Mesri and Godlewski 1977) to predict the response of an organic clay and a fibrous peat compressed under oedometric conditions. The effect of prolonged load increment durations and the application of load increment ratios considerably in excess of the value of unity applied in standard 24-hour oedometer tests is discussed as it has a direct bearing on conventional settlement predictions associated with pre-loading/surcharging techniques.