Explaining the effect of biopolymer-based pore fluid on soil behavior using coarse grained molecular dynamics simulations

The goal of this paper is to numerically assess the impact of biopolymer-based pore fluid on soil behavior. The use of biopolymer-based pore fluids is increasing nowadays due to advancements in biogeotechnology methods. These advancements, however, rely on trial and error identifying the most suitable biopolymer and its concentration to avoid strength losses in the soil. Furthermore, the use of clay fillers to stabilize biopolymers preserving the overall strength of the soil is performed arbitrarily without scientific basis. In this study, the response of biopolymer-based pore fluid is modeled using coarse-grained molecular dynamics and compared to the response of conventional pore water. The impact of different percentages of clay filler is also investigated. The results of this study show that the viscosity of filler-stabilized biopolymers at low shearing speeds is significantly higher than that of traditional pore water. However, the viscosity of these biopolymers drops significantly reaching to the water viscosity as the shearing speed (i.e., rate) increases. Such response was observed for all clay filler percentages with an increase in the viscosity as the filler percentage increases. Furthermore, using a less concentrated biopolymer in the pore fluid showed a significant reduction in the viscosity. These results will allow better design and selection of the biopolymer-based pore fluids for various biogeotechnology applications.