Micro-modelling of stone masonry template buildings as a strategy for seismic risk assessment in developing countries

Seismic risk for a stone masonry template health centre developed by the NGO Pahar Trust is assessed for the entirety of Nepal, accounting for the latest probabilistic seismic hazard analysis available for the country. Micro-modelling in OpenSees is employed to derive a high-fidelity model of the Pahar Trust health centre and to perform a cloud analysis deriving fragility curves. Regularisation criteria are carried out to optimise irregular stone masonry modelling and validated against consolidated analytical formulations and recent experimental campaigns. The study contributes to establishing a strategy for defining the implicit seismic risk for the case of implementation of template designs in a highly variable seismic hazard for which a detailed numerical study can be applied to an entire region. Micro-modelling represents a very convenient approach given the limited availability in low and middle-income countries of experimental results for the masonry and the easier accessibility of separate material tests on the masonry components. Results are also benchmarked against empirical and numerical studies developed in the literature for the same country context finding a relatively good matching with a less conservative results in terms of vulnerability due to the higher accuracy of the modelling strategy. Risk assessment results obtained for the health centre are comparable to the acceptable risk targets for developed countries in all cases for which quality controls guarantee the rigorous implementation of structural details.