Bhutanese Ornamental Windows and Its Contribution to Inter-story Drift In Rammed Earth Structure- A Case Study

The vernacular structures in Bhutan attributes to the country’s rich tradition and culture. These structures built during 15th – 16th centuries without any technical guidelines still exist with profound pride as Bhutanese traditional buildings even after experiencing great earthquake in the past. Bhutanese vernacular structures exist in various types; while this research paper focuses only on the structural analysis of a commonly found rammed earth house in Paro, considering the effect due to Rabsel. Rabsel is a Bhutanese ornamental window having significant aesthetic and cultural values. These heavy timber components fixed to the wall has tendency to add weights to the wall. During the seismic activity, this might lead to vertical acceleration and overturning moment, which generates a typical P-delta effect inducing lateral as well as vertical loads on the walls. Hence, it is the primary cause of tilting Rabsel, cracking, and buckling of walls as observed in post-earthquake scenarios. Hence, the effect of Rabsel as a shear and moment contributing component will be looked into which is not incorporated in any design process and software. Linear static analysis is performed considering varying weights of Rabsel and the results obtained are used for numerical modeling. The results were found to form the paramount philosophy of designing and executing the construction of future traditional buildings in Bhutan.