Large-strain consolidation model for composite foundation improved with stone columns

Large-strain non-linear consolidation models are critical for accurately predicting the behaviour of soft soils, yet research on such models for composite foundations reinforced by stone columns in highly compressible soft soils remains limited. A double logarithmic model was adopted to describe the non-linear compressibility and permeability of highly compressible soft soils. Building on Gibson’s large-strain consolidation theory, the model accounts for smear effects, well resistance and four loading types. Both analytical and numerical solutions were developed to solve the governing equations, and their validity was rigorously verified through comparisons with prior studies and an engineering case. The validated solutions were further utilised to explore the influence of initial effective stress distribution modes on consolidation behaviour. The results indicate that the consolidation rate predicted by the non-linear model is faster when Ic(α − 2) − 1 < 1, but demonstrates slower consolidation when Ic(α − 2) − 1 > 1. The consolidation rate under the linear distribution of self-weight stress is always faster than that under the uniform distribution, particularly in terms of settlement characteristics.