An elastic visco-plastic model for soft soil with reference to radial consolidation

Springer Nature Singapore Pte Ltd 2019. The time-dependent stress-strain behaviour of soft soil due to its viscous nature affects its long-term settlement and pore water dissipation. A novel mathematical model developed using the Peaceman-Rachford ADI scheme (P-R FD Scheme) can describe the visco-plastic behaviour of soft clay with a non-Darcian flow function; this model is a combination of the basic radial consolidation equation developed by Barron and Bjerrum\u27s time-equivalent (Bjerrum in Geotechnique 17:81-118, 1967) concept that incorporates Yin and Graham\u27s (Can Geotech J 26:199-209, 1989b) visco-plastic parameters. The settlement and excess pore water pressure obtained from this model are then compared with preexisting models such as a Class C prediction for the Ballina trial embankment at National Field Testing Facility (NFTF). This elastic visco-plastic model provides better results in terms of settlement and pore water pressure with the field data, although the excess pore water pressure that did not dissipate after one year is mainly due to the piezometers becoming biologically and chemically clogged in terrain with acid sulphate soil (ASS)