Specification of design wind loads in India

Abstract

Codes in current use in India for specifying design wind loads for structures are analysed, and shown to be inconsistent with available data on extremes. Thus, it is found that while the National Building Code specifies the highest wind loads on the east coast and western Gujarat, the observed extreme winds are highest in the eastern Gangetic valley. As the consequences of under-specification can be serious, a careful re-examination of the code seems called for. It is argued that although the available data on extremes may not be complete, they provide a more rational basis for formulating a building code; as wind loads become more important in construction engineering a serious effort at generating and analysing the required meteorological data seems highly worthwhile. However, procedures followed elsewhere for predicting extreme winds and the nature of gusts need to be validated for the country. In addition there is also a need to study certain meteorological phenomena peculiar to the Indian subcontinent like the duststorms and the nor’westers of north India.