Damage Assessment and Dynamic Characteristics of Temples in Nepal Post Gorkha 2015 Earthquake

The aim of this paper is to identify, also through micro tremor analysis and numerical analysis, the collapse’s mechanisms of the Nepalese wood-masonry monuments damaged by the 2015 seismic event that struck Kathmandu and its valley. The research analyses two case studies: The Radha Krishna and the Bhimsen Temples. After a careful anamnesis based on visual inspection and hypotheses on the temple’s structural behaviour, a global dynamic ambient test (micro tremor) was carried out for qualitative characterisation of the structural system, residual stiffness and strengths. First, numerical models have been calibrated on mechanical parameters present in literature. The difference between experimental results and numerical model values is higher than 100% in the Radha Krishna temple and 70% in the case of Bhimsen temple. Considering this results, the models were calibrated on the experimental results. The modal analysis shows important mixed effect of torsional and flectional mode in the case of the Radha Krishna temple while in the Bhimsen temple local effects prevail. The capacity curve of Radha Krishna temple shows behavior close to collapse at 0.26 g, while the Bhimsen temple presents important damage at 0.3 in Z direction and 0.23 in X direction.