Simulating reactive soil and substructure interaction using a simplified hydro-mechanical finite element model dependent on soil saturation, suction and moisture-swelling relationship

Abstract

Lightweight structures are susceptible to damage caused by cyclic shrink-swell movements of clayey soils amounting to significant aggregated global financial loss for repair costs. Due to this issue, the main aim of this study is to develop an improved method for a deeper understanding of the soil-structure behaviour and for a more practical design process of substructures through a coupled hydro-mechanical finite element model. The developed model uses the relationship between the degree of saturation, soil suction and volumetric strain using a three-dimensional finite element approach. The developed model was validated using three case studies. The first case study verified its ability to simulate movements of a ground and deformation of a substructure due to changes in soil saturation and suction using field data from the literature. The second case study verified the ability of the developed model to simulate cracking of a substructure induced by soil movements using field data from the literature. The third case study compared simulations of hypothetical stiffened and waffle rafts using the developed coupled model and a decoupled traditional method being used in practice. The developed model was observed to have a satisfactory performance, which overcome most limitations of traditional substructure design methods.