Helix Bridge - Akshay Gaurav
- 1. Helix Bridge - Architectural & structural innovation Presentation by, Akshay Gaurav GNDEC, Ludhiana 1°17’15.44°N, 103°51’38.15°E
- 2. Contents • Introduction • Architecture • Material Selection • Design • Analysis • Fabrication & Erection • References & Bibliography
- 3. Introduction • Carries – Pedestrian • Crosses – Singapore River • Location – Queen Elizabeth Walk, Esplanade Mall, Singapore • Official Name – The Helix • Other Name – Double Helix Bridge • Material – Duplex stainless Steel • Opened – 24 April 2010 ( 18 July 2010 ) • Cost at Completion – 82,900 SGD ( 41,45,000 INR / 61,434.26 USD ) • Area – 1379.08 sq.metre • Architect – COX Group Pte Ltd (Australia) & Architects 61 (Singapore) • Consultant – Arup (Civil, Mechanical, Electrical, Lighting), Tierra Design (Landscape), David Langdon Seah (Cost) • Builder – Sato Kogyo (S) Pte Ltd • Managed & Maintained by – Land Transport Authority
- 5. Architecture • Inspiration – Geometric helicoidal arrangement of DNA • Team – Cox Group, Arup Engineers & Architect 61 • Lighting – Dynamic multi colored light emitting diode(LED) • 4 Viewing pods – Panoramic view of Singapore skyline. • World Architecture Festival Awards 2010 - “World’s Best Transport Building” • BCA Design & Engineering Safety Excellence Award 2011 – Building & Construction Authority (BCA) • Industrial, Transport & Infrastructure Category 11th Singapore Institute of Architect’s Architectural Design Awards. • World’s first curved double helix bridge
- 7. Material Selection Duplex stainless steels have a two-phase microstructure of austenite and ferrite grains. The duplex structure gives this family of stainless steels a combination of attractive properties. Duplex stainless steels are about twice as strong as regular austenitic or ferritic stainless steels. • Local planners place noticeable emphasis on quality urban design. • Designers are encouraged to use sustainable, low maintenance and aesthetically pleasing materials. • Environment of Singapore is hot, humid, industrial and coastal. • Stainless steel give designers a good option. • Grade 1.4462 of stainless steel provided the requirements of good availability, cost effectiveness, ease of fabrication and the structural / architectural requirements. • It also provides high resistance to stress corrosion cracking. • Cost of duplex steel was equivalent to potential costs of using carbon steel.
- 8. Design • Selected out of 36 design submissions. • Two set of spirals, one in another interconnected by tension rods spiraling in different directions. • Total length – 280m • Width of deck – 6m • Major helix diameter – 10.8m • Minor helix diameter – 9.4m • Total length of steel tubes – 2,250m • Total weight – 1700 tonnes • Maximum Capacity – 10,000 people • Sunshade – Canopies (Fritted glass & perforated steel mesh). • Computer controlled LED lighting.
- 11. Analysis • Extensive numerical analysis was completed using structural optimization software • Due to complexity of structures, 3D simulations are used as analysis tool. • Prior to specifying materials or even finalizing designs, the bridge was modelled using 3D software. • Non-linear analysis was also carried. • Robustness studies was also important to carry out.
- 13. Fabrication & Erection • The helix is fabricated from approx. 650 tonnes of Duplex stainless steel & 1000 tonnes of Carbon steel. • The steel was delivered from the supplier in Europe to Singapore and then fabricated in Johor, Malaysia. • The bridge components were fabricated to the maximum transportable dimension. • Average length of components was 11m. • Trial assembly of segments of the bridge was conducted in the workshop. • Installation began with the lower deck components and completed at the highest level of the bridge. • Major and minor helices were welded on site and all the light struts and tension rods were pinned.
- 20. References & Bibliography 1) https://www.steel-sci.org 2) http://www.archdaily.com/185400/helix-bridge-cox-architecture-with-architects-61/ 3) https://www.youtube.com/watch?v=WHFpZc3nryE 4) https://en.Wikipedia.org/wiki/Arup Group 5) https://en.Wikipedia.org/wiki/Stainless_steel 6) https://en.Wikipedia.org/wiki/Austenitic_stainless_steel 7) https://en.Wikipedia.org/wiki/Helix_Bridge 8) https://en.wikipedia.org/wiki/BS_5950