Abstract:
Bihar state sits on a high seismic zone which falls on the boundary of a convergent tectonic plate
near the Bihar-Nepal border. Out of 38 districts in Bihar, 8 districts lie in Zone V. 24 districts in
Zone IV and 6 districts in Zone Ill of the seismic zone. The Himalayan tectonic plate is moving
towards the Indian Plate slowly and gradually. This dangerous plate tectonic behaviour has
already caused a number of devastating earthquakes in the past. The continuous movement of
plate projects an alarming picture for the state in future. The state has experienced high levels of
destruction each time. The project focuses on the mitigation of the damage caused due to
scenario earthquake in the state of Bihar. The Bihar-Nepal Earthquake-1934 has been taken as
the scenario earthquake in this study. The term Scenario Earthquake' here refers to a condition
in which a hypothetical recurrence of an earthquake is assumed in Bihar; whose magnitude,
intensity and epicentre is considered same as of any previous earthquake of the focussed region
of study. For the same reason, risk associated with the state has been identified by performing a
Seismic Risk Assessment. Total expected direct and indirect losses are calculated in terms of
rupees and number of deaths (caused due to the collapse of buildings) respectively.
Consequently, the results obtained out of this assessment projects the most vulnerable districts of
the state during any scenario earthquake. The project then discusses about the prevailing housing
typologies in Bihar state. The most common type of building construction in the region, i.e.
Burnt Brick Construction; has been identified and discussed in context of the state. Since, Bihar
has witnessed a number of earthquakes in the past; buildings of the state have suffered great
damage. In this context, the building deficiencies and damage trend observed in such structures
have been laid out. Further, based on scenario studies, the first eight worst affected districts of
the state have been projected. The typical types of cracks and building failures observed in burnt
brick masonry structure due to the previous earthquakes are also outlined. Eventually,
retrofitting recommendations for this typical construction has been given.
