Application of high strength niobium grain-refined steels to a re-design of the Singapore National Stadium Roof

The new 55,000 seat National Stadium is the centrepiece of the Singapore Sports Hub project, due to be completed in early 2014. The roof structure for the stadium is a highly efficient dome spanning 310 m with an elevation of 85 m from the ground level. When complete, the fixed roof will be the largest clear span dome roof in the world and supports a symmetrical movable roof in two halves. The fixed roof structure is formed by a series of steel arch trusses varying in depth from 5 m at the centre to 2.5 m at the base and is supported by a post-tensioned concrete ring beam. The trusses are constructed from circular hollow section (CHS) elements and span in multiple directions to form a highly efficient braced dome structure. Due to the movable roof there is a regularly varying load on the structure. Whilst the structure is not highly fatigue sensitive, fluctuating loads had to be carefully considered in the design to ensure that they could be accommodated within the design of the connections. The construction design was based on S355 steel using cold-formed CHS members with hot finished S355 CHS elements used only for thicker sections. Whilst serviceability issues such as deflection and fatigue were design considerations, the structure was predominantly strength governed. This paper considers the potential savings in material use that could have been made if higher strength, high elongation steel had been economically viable and could have been competitively tendered. It is shown that it could be possible to make a significant saving on element steelwork if hot finished niobium grain-refined S500 can be adopted for similar projects in the future. (AU) Copyright © 2015 Companhia Brasileira de Metalurgia e Mineração (CBMM) All rights reserved.