SEISMIC PERFORMANCE EVALUATION OF TWO TIERED BRICK MASONRYPAGODA TEMPLE: A CASE STUDY ON NARSINGHA TEMPLE

Abstract

The subduction of the Indian plate under the Eurasian plate initiated about 40-55 million years ago, have resulted in frequent devastating earthquakes in Nepal. The two major earthquakes in last 100 years, 1934 Nepal Bihar earthquake and 2015 Gorkha earthquake, have caused extensive damage to lives and properties. The post-earthquake damage assessment studies have highlighted the severe structural damages to cultural heritage and monuments, especially Pagoda temples, and discussed the need of in-depth study required for strengthening and restoration of the damaged temples. This research intends to depict the seismic behavior and capacity of a multi-tier brick masonry pagoda temple under seismic load. As a case study, a two-tier pagoda temple, the Narsingha temple has been studied. The history of this Hindu temple dates back to 14 th century located at the historic center of Bhaktapur, while the temple structure collapsed completely during 1934 earthquake in Nepal. A nonlinear three-dimensional finite element model of the Narsingha Temple was developed and the seismic performance evaluation of the temple was assessed by undertaking modal eigen-value and nonlinear static analyses. Sensitivity analysis of physical properties of the masonry was undertaken to study their response on behavior of the structure. Finally, the vulnerability of the temple was expressed in terms of fragility curve for various performance level. From the results analysis, the damage patterns were assessed and the performance level of the temple was determined with the help of demand spectrum obtained from NBC 105:2020 and capacity curve obtained from the pushover analysis. Also, the dynamic identification of the temple showed the fundamental time period to be in the range 0.3-0.35 sec. Results from this research could contribute towards determining the seismic fragility of the multi-tier temples and eventually contribute in strategic planning and conservation of such heritage across Nepal.