Modelling and analysis of South Indian temple structures under earthquake loading

Abstract

The gopuram (multi-tiered entrance gateway) and the mandapam (pillared multi-purpose hall) are two representative structural forms of South Indian temples. Modelling and seismic analysis of a typical 9-tier gopuram and, 4- and 16-pillared mandapam of the 16th century AD Ekambareswar Temple in Kancheepuram, South India, are discussed. The seismic input is based on a probabilistic seismic hazard analysis of the archaeological site. Two modelling strategies, namely lumped plasticity and distributed plasticity modelling, and three analysis approaches, namely linear dynamic, non-linear, static and dynamic analyses were adopted for the seismic assessment of the gopuram. Unlike slender masonry towers, the vulnerable part of the gopuram could be at the upper levels, which is attributable to higher mode effects, and reduction in cross section and axial stresses. Finite element and limit analysis approaches were adopted for the assessment of the mandapam. Potential collapse mechanisms were identified, and the governing collapse of lateral load, calculated based on limit theory, was compared with the seismic demand as a safety check. Simple relations, as a means of rapid preliminary seismic assessment, are proposed for the mandapam.