Seismic sensitivity analysis of the common structural components of Nepalese Pagoda temples

Nepal is located in a highly active tectonic region of the Himalayan belt, one of the most severe earthquake prone areas of the world. Nepal is lying between the Indian and the Eurasian plate, which are moving continuously, resulting in frequent devastating earthquakes. Moreover, different authors state that the accumulated slip deficit (central seismic gap) is likely to produce large earthquakes in the future. Cultural heritage buildings and monuments are, therefore, at risk, and the eventual cultural loss in the consequence of an earthquake is incalculable. Post-seismic surveys of past earthquakes have shown the potential damage that unreinforced masonry structures, particularly Pagoda temples, may suffer in future earthquakes. Most of the Nepalese Pagoda temples, erected during XIV century, are considered non-engineered constructions that follow very simple rules and construction detailing in respect to seismic resistance requirements and, in some cases, without any concern for seismic action. Presently, conservation and restoration of Nepalese temples is one of the major concerns, since they are considered world heritage with universal value. The present paper is devoted to outline particular building characteristics of the UNESCO classified Nepalese Pagoda temples and the common structural fragilities, which may affect their seismic performance. Moreover, based on a parametric sensitivity analysis, structural weaknesses and fragilities of Pagoda temples were identified associated to the local and traditional construction techniques, detailing and common damages.