Seismic assessment of URM pier spandrel systems via efficient computational modeling strategies

Predicting the seismic behavior of unreinforced masonry (URM) structural systems is a complex task, given various inherent sources of uncertainty associated with material properties, geometry, and boundary conditions. As the selection of computational strategies is a trade-off between prediction accuracy and computational cost, it is often challenging to find a consensus. To this end, this study presents three computational modeling strategies that can be used in the seismic analysis of URM structures. The first two approaches utilize the discrete element method (DEM) and are based on pre-defined macro-block mechanisms, whereas the third approach makes use of the computational thrust line analysis (CTLA). Such methods provide accurate predictions on the in-plane lateral load-carrying capacity of URM pier-spandrel structures with a reasonable computational cost and fewer input parameters, making them efficient compared to detailed numerical models. The results are found to be in good agreement with the experimental data on two full-scale pier-spandrel systems with either timber lintel or shallow arch above a central opening. This study also provides a detailed comparison of the applied methods and suggests multi-level use of proposed modeling strategies for better informed decision-making, starting from the most simplified method (CTLA) towards the advanced solutions as more information is collected.