Uncertainty analysis of the effect of grout injection on the deformation of multi-wythe stone masonry walls

The eighteenth century Prince of Wales Fort in Manitoba Canada has experienced extensive freeze-thaw damage and mortar washout within the escarp walls resulting in distress and failures at multiple locations. Injection of grout could counteract this degradation of structural stability. However existing literature provides little guidance as to the improvement level that could be expected, especially with respect to out-of-plane performance. As such, the proposed treatment was modelled to include a high level of uncertainty in the system through the application of a Random Field Finite Element Micro-modelling technique. A Latin Hyper cube simulation method was used in conjunction with a parametric finite element model to randomize the material properties of each stone and relevant grouting layers. The numerical results predicted that the stone-grout bond was the most critical parameter in the proposed intervention, and that in the grouted wall sections, collapse would be avoided and lateral displacements stabilized with the proposed treatment.