A Comparative Study on the Seismic Performance of the Different Types of Bamboo Stilt Houses of North-East India

The north-eastern part of India which includes the seven sister states and Sikkim is very prone to seismic activities. Over the years, a number of earthquakes have caused large disturbances to public life and property in this region. The population in this region mainly consists of indigenous tribes, who inhabit the forests and rural areas. Hence the predominant housing in this area is the traditional vernacular type. Although, there are numerous types of vernacular housing typical to each tribe inhabiting the region; they can be broadly classified into mainly four types: Kutchha houses, Assam/Ikra type houses, Bamboo houses on stilts and High pitched roof kutchha houses, characterized with some spatial variations. Keeping in mind the difficult conditions prevalent here, the traditional houses are built with features to combat the various natural calamities, without loss of life and property. This is evident from the past records of the earthquakes, where the traditional houses were least affected. Although qualitative records of the seismic resilience of these houses are available, the same have not been backed by quantitative studies. This paper seeks to address this gap, by quantitatively analysing the seismic performance. For this purpose, the Bamboo house typology on stilts built on a slope is selected and a comparative study is conducted on the different types of prevalent stilt systems to understand which one provides for the maximum seismic resistance. From the preliminary investigations, it has been found out that the cross bamboo stilts provides the maximum resistance, the details of which are presented in the paper.