Learning from Façade Failures over Urban Landscape: Aftermath of Cyclone Vardah

Abstract

The failure of building façades is one of the prime factors governing economic losses due to extreme wind events. This paper presents the details of a postdisaster field investigation performed after the very severe cyclonic storm Vardah in the southern peninsular part of India. The paper documents a total of 164 cyclone-induced façade failures. Probable failure mechanisms and the location of the critical zones prone to façade failure are identified. A framework involving a two-tier categorization of the observed façade failures is proposed. The vulnerability of the façade components, such as panel, connections, and supporting back frames, are evaluated and quantified by their relative damage potential level of 53%, 35%, and 12%, respectively. A detailed study of the damage data indicates that inappropriate panel-to-mullion connections, the impact of wind-borne debris, the interference effect, and adopting inappropriate aerodynamic modifications are amongst the premier causes for façade failures. Finally, corrective measures are prescribed to improve the façade design methodology in order to evolve an improved resilient urban façade system.