Design and Erection of Complex Steel Roof Structures in Airports

The boom in the development of infrastructures such as airports in the recent years in India has resulted in development of new green field airports as well as expansion of existing airports. All the developing airports infrastructures were being evolved with modern architectural design to match with global trend which in turn calls for a complex structural design with a combination of reinforced concrete and structural steel. To add further, there is a significant increase in the use of structural steel primarily to attain a column-free space and to achieve the desired architectural shapes. Usually most of the airports will be highly appealing and it forms the gate way for the big wide world outside. In any airport, passengers’ comfort must be ensured, journey time to be shortened, high standards of security to be maintained, operational efficiency to be enhanced along with stake holder requirements and various other needs have to be catered for, all under one roof. In airports, landside infrastructure includes Terminal Building, Piers, Concourse and Airside includes Runways. Terminal and Pier structures were designed and constructed with conventional reinforced concrete Beam-Column-slab system and foundation (Isolated and combined pad footing/pile) system as per the geotechnical investigation and recommendation. Based on the functional requirement and to have column-free space, the departure level was proposed to have steel roof system typically with 18 m × 45 m column grid spacing. Profile of the terminal roof is a unidirectional reverse compound curve, and the profile of the Pier roof is composed of bidirectional curvature, i.e., the profile is curved in both in longitudinal and transverse direction with a gradual increase in the level of the roof ridge. This paper narrates and focuses on the conceptualization of a peculiar architectural roof profile, the way supporting structural roof truss system was evolved, complexities involved in achieving the curved profiles, connection designs, coordination and detailing in BIM, and finally, the fabrication and erection of trusses by adopting the most appropriate construction methodologies.