Behaviour of buildings during Karaikal Cyclone - December 1993

This paper briefly reviews the behaviour of buildings during the Karaikal cyclone (December 1993). A brief description of the cyclone is also given. The cyclone damage survey revealed that large number of low rise buildings have been severely affected by the cyclone. The performance of different types of low-rise buildings are assessed. Mud walls of thatched huts were severely damaged compared to brick walls. Brick walls too were seen to fail due to their poor lateral strength. Steel trusses and columns of industrial sheds were not seen damaged during the cyclone. Thatches due to their low dead weight and improper fixing are severely damaged. Though roofs of houses and industrial sheds were affected to lesser extent, the rupee losses caused by these failures are high. The damage to the roofs is found to be limited to certain locations like the ridges, eaves and the hips. Roofing tiles with higher dead weight performed better. Certain measures like providing a band of mortar along the critical regions, adopting certain roof geometries and the use of proper connections are seen to reduce the damage considerably. For AC Sheet roofing certain recommendations are given for better performance against cyclonic windloads.