Digital Recording and Non Destructive Investigation of Nyatapola Temple after Gorkha Earthquake 2015

As a result of the Gorkha earthquake in Nepal on April 25, 2015 and the aftershock that followed on May 12, a large number of heritage structures in Nepal were destroyed and significantly damaged. In particular, the seven monument zones of the Kathmandu Valley World Heritage Site suffered extensive damage. Out of 195 surveyed monuments, 38 have completely collapsed and 157 were partially damaged (DoA, 2015). This paper focuses on one of the areas with the highest heritage value, the historic city of Bhaktapur. It is recognized as a UNESCO World Heritage Site (WHS) and contains many structures of significant cultural and religious importance for the population of the Kathmandu valley. The understanding of these historical structures is principal for the reconstruction and maintenance of the heritage value of the area. In order to achieve this objective, an interdisciplinary collaboration between local experts, engineers and architects is proposed to understand the traditional construction technology and physical response to the earthquake. This paper develops the study of the Nyatapola Temple in detail. The documentation and evaluation of this temple is achieved only from nondestructive techniques: laser scanning, terrestrial and aerial photogrammetry, geo-radar and micro-tremor dynamic analysis. The purpose of this study is to form the basis for a structural analysis to assess the anticipated future seismic performance of the Nyatapola Temple. The use of digital technology aims to shed light on the structural behaviour of the temple and its response to an earthquake. The particular interest in the composition of the plinth and its articulation with the superior hybrid structure has the objective of understanding the structural behaviour of the whole for the future structural rehabilitation.