Numerical modelling of hydro-mechanical behaviour of ground settlement due to rising water table in loess

Abstract

The numerical simulation of collapsible settlement in loess soil subjected to rising ground water table is presented in this paper. A coupled hydro-mechanical model is proposed. Comparisons between the results of numerical simulations and those of oedometer and in situ water immersion field test in Lanzhou, northwest China, reveal good agreement, which validates the proposed model formulation. Factors that influence the ground settlement of loess including initial elevation of ground water table, rising water height and velocity are then evaluated. The results of the analyses reveal that the most critical situation of largest possible ground settlement due to ground water rising in loess involves initial water table elevation of 10 m and rising water velocity of 0.5 m/year. Two upper bound lines of predicted maximum possible ground settlement are proposed to facilitate a preliminary quick evaluation of ground settlement due to rising water under different water table scenarios in loess.