A finite strain elastic-viscoplastic consolidation model for layered soft soils considering self-weight and nonlinear creep

Abstract

This paper presents a numerical model, called consolidation settlement - elastic-viscoplastic (CS-EVP), for the consolidation of layered soft soils, including soil self-weight and time-dependent compressibility effects. CS-EVP was developed using the piecewise-linear method for large-strain consolidation and elastic-viscoplastic model for time-dependent soil compressibility. The model accounts for vertical strain, soil self-weight, nonlinear hydraulic conductivity and compressibility, nonlinear creep with limited creep strain, and time-dependent surcharge and/or vacuum loading for layered heterogeneous soils. The accuracy of CS-EVP is verified by comparing calculated values with the results from finite-element simulations and a large-scale laboratory vacuum consolidation test of soft soil slurry. Lastly, simulated settlements and excess pore pressure profiles are compared with field measurements for embankment loading in Väsby, Sweden. The results indicate that CS-EVP provides good estimates of long-term large-strain consolidation under both laboratory and field conditions.