Effects of creep and permeability coefficient in soft soil improvement with the use of PVDS and vacuum-surcharge preloading

Abstract

Accurate prediction of both primary and secondary consolidation settlements in saturated soft soils is critical for the ground improvement method. This study presents 2D and 3D finite element method of vacuum - surcharge preloading combined with prefabricated vertical drains (PVDs), conducting two soi models: Soft Soil (SS) and Soft Soil Creep (SSC). The results demonstrate that the SSC soil model settlement predictions that closely match field observations data, whereas the SS model,  which neglects soil creep - significantly underestimates settlement. Furthermore, comparison of 2D and 3D simulations highlights the necessity of calibrating soil permeability when converting from axisymmetric to plane-strain calculation to ensure both modeling accuracy and cost-effective in soft soil improvement with the use of PVDs and vacuum-surcharge preloading.