Earthquake Vulnerability Assessment of House Constructions in Himalayas

Abstract

The entire Himalayan range is highly prone to earthquake s and the latest Kashmir earthquake (October 08, 2005) has once again drawn our attention to the highly vulnerable Himalayan settlements. Narcndranagar block of the Himalayan state of Uttaranchal lies in seismic zone IV of the seismic zoning map of India. Like in other hilly areas Narendranagar block also witnessed the traditional practice of house construction being replaced by modern construction materials and practices without the knowledge of earthquake resistant techniques rendering the present buildings
more vulnerable to earthquakes. The objective of this paper is to assess the vulnerability of the buildings so that corrective measures can be taken to minimize the destruction during future earthquakes. Types of buildings observed in the entire block with di ffe rent combi nations of materials and their earthquake behaviours are explained. The existing structures are grouped into vulnerability categories Vl , V2 and V3 as per the descriptions provided in the MSK (Medvedev Sponheaer- Karnik) Intensity Scale. Damage estimation for a hypothetical earthquate is carried
out for the Narcndranagar block. Conclusions and recommendations suggesting use of such studies in all earthquake prone areas of the Trans Himalayan region are provided.

Key Words : Earthquake, Vulnerability, Resistance , Risk, Construction typology.