Modelling of biogrout propagation in soils

Bacterial strains producing urease can have a major impact on the natural calcite precipitation process if they are supplied with nutrients and urea. In Microbial Induced Calcite Precipitation (MICP) process, the precipitated calcite acts as a cementing agent in the soil, offering an alternative sustainable and cost-effective grouting technique. The miscible and reactive biogrout injection in saturated, deformable soils need however to be better understood and described to more effectively design the grouting technique. A research work is therefore carried out on this topic. The field equations for biogrout transport are established based on the understanding of the complex involved processes. The related constitutive equations for stress-strain relationship and fluid flow are considered. The resulting set of field equations is discretized and implemented into an advanced finite element code. Finite element modelling of column injection tests is carried out to validate the mathematical formulation and to demonstrate the potentiality of the developed model.