RV College of Engineering, Bangalore, Department of Civil Engineering

Construction of domes has been practiced in India for nearly fifteen centuries. Corbelled stone roofs have been built since the fifth century by Temple builders. With the advent of Islamic rule in the twelfth century, construction of arches, domes and vaults in the arcuate mode came into vogue. However, very often, corbelled and arcuate modes of dome and vault construction have been used conjunctively. The performance of the various domes and vaults in India has not been event-free. The immense dome of GOL GUMBAZ at Bijapur, suffered severe meridional cracking sometime in the fourth decade of the 20th century. This was repaired in the late forties by providing steel reinforcement and guniting on both the surfaces of the dome. The reasons for the cracking have been examined by reference to shell theory and the current understanding of behaviour of lime mortars. The lack of durability of exposed basalt structures in Bijapur is also highlighted. The remarkable large span vaults of TAMIL NADU are examined to understand the structural mechanisms used towithstand the large lateral thrusts. Examples of cracks in the crowns of certain vaults due to inadequate management of lateral thrust are also brought out. The crack patterns of many flat domes which have reached a state of partial collapse are presented.
Key words
historical buildings, masonry domes, masonry vaults, cracking, lateral thrust