Large-strain modelling for vacuum-assisted consolidation combined with thermal energy

By integrating thermal energy into the reclamation process, the newly emerging thermo-promoted vacuum preloading (TPVP) can desirably enhance the dewatering efficiency for high-water-content slurry. Regrettably, barely no theoretical contributions are available to facilitate the engineering design of this combined technique. In light of this, a novel analytical model is developed for the large-strain nonlinear thermal consolidation of TPVP-treated slurry. This study comprehensively incorporates the smear effect and well resistance of prefabricated vertical drains (PVD), attenuation of vacuum pressure, and temperature-dependent engineering properties. The resulting governing equations and analytical solutions for two typical loading schemes are derived under the equal strain assumption and steady-state heat transfer condition. The predictive capability of the proposed model is validated against existing models and measured data with excellent agreements. Subsequently, the influence of several crucial parameters on the consolidation behavior is explored through parametric analysis. The results reveal that increasing the final temperature Tu can promote consolidation efficiency and enlarge the final settlement, while this promotional effect will recede as Tu further rises. The crossover pattern observed in the settlement curves underscores the necessity of considering soil non-linearity in theoretical derivations. In summary, these findings provide fundamental insights into the field-scale applicability and cost optimization of TPVP.