Novel 3D distinct element limit analysis model for the seismic vulnerability evaluation of historical masonry pagodas of major importance in China

A new distinct element DEM limit analysis approach is presented and applied to the seismic vulnerability evaluation of an ancient masonry pagoda in China. The numerical model relies on the assemblage of infinitely resistant hexahedral elements and rigid plastic four-nodded interfaces, where all the internal dissipation lumps, constraining cracks to spread between adjoining elements. So, it is neither an upper bound nor a lower bound, but rather a DEM limit analysis. A masonry pagoda, Huqiu pagoda located in China, was selected as a case study to benchmark the model under the application of a seismic load. It is an octagonal masonry pagoda with a total of 7 floors and a height of 48.2m. The results show that the failure mechanisms found by limit analysis are basically vertical splitting with bending at the base. The results obtained by this research method are consistent with the actual behavior of masonry pagodas, which shows its suitability in direct applications by practitioners.