Scope Twin-Tower Complex, Delhi

Abstract

The twin-tower office complex under construction at Laxmi Nagar, Delhi is a part of the District Centre being developed by the Delhi Development Authority. The structure is in the form of two high-rise curvilinear tower blocks, rising above a four-storey circular podium block and includes two basements for parking and a central mushroom. Both towers are of different heights, the taller tower with a total of 22 storeys and the other with 17 storeys, including provision of a heliport over the terrace. The total built-up area in both the towers, the four-storeyed low level structure and the two basements, is over 100000 m2. The diameter of podium structure at its base is about 110 m, which gives an idea of the large size of the structure (Fig. 1).The structural analysis involved a threedimensional frame analysis for all loading cases, including wind loads based on wind tunnel studies and seismic loads derived from model analysis. A wind tunnel study was carried Out because of the unconventional shape of the structure and the disposition of the towers. Salient features of design are the curved beams of large spans, slipformed lift cores, and pre-cast floor panels.Large diameter bored piles of 1200 mm diameter and 22 m length were used as foundations on which a 1.5 m thick raft was cast without expansion joints, through the use of pumped concrete in association with a batching plant.