An optimised multi-level method for the pushover analysis of historic masonry structures accounting for the actual masonry pattern

In this paper, we propose an optimised multi-level method to efficiently account for the actual masonry pattern in the pushover analysis of historic masonry structures. The method begins with a rigid block-based limit analysis accounting for the actual masonry pattern to identify realistic failure mechanisms. Next, macro-blocks that outline the failure mechanism are identified using a novel optimised procedure that includes a heuristic search, which minimises the number of blocks and non-linear interfaces in the subsequent analyses. Subsequently, macro-blocks are modelled as homogeneous material interacting via cohesive-frictional interfaces in a finite element environment where pushover analysis produces force–displacement curves. Validation against various structural benchmarks with regular and irregular masonry patterns and different loading configurations demonstrates the method's accuracy and competitiveness compared to micro-modelling approaches. Results show up to a 90% reduction in computational time and the number of blocks, with a maximum difference of about 5% in numerical prediction of force capacity.