SMart BEAM™ Lightweight Welded H-Beam adopted for beams supporting sound absorbing panels for underside of elevated roads of Second Keihan Highway, in recognition of lightweight merit
- Sumitomo Metal Industries, Ltd.
Sumitomo Metal Industries, Ltd.'s (Sumitomo Metals) SMart BEAM™ lightweight welded H-beam has been highly acclaimed for its lightweight merits. Consequently, a large quantity of these beams is being adopted in the Second Keihan Highway, which is currently under construction. This Highway is a toll road with a length of 28.3 km that links Kyoto and Osaka, and is scheduled to open at March 20, 2010. The installed area of sound absorbing panels for the underside of the elevated road is approximately 140,000 m2, and Sumitomo Metals has received orders for approximately 1,500 tons of the roughly 1,800 tons of lightweight welded H-beams to be used as supporting beams.
1. Lightweight welded H-beams
Lightweight welded H-beams are continuously manufactured from hot-rolled coils by means of high-frequency resistance welding. As they are less thick than standard rolled H-beams, it is possible to reduce the weight of steel material used by a maximum of around 40% when compared to rolled H-beams with the same section properties*. In addition, as SMart BEAM™ lightweight welded H-beams are welded after cutting hot-rolled coils to the necessary width, it is possible to manufacture various sizes, dimensional precision is high, and these products are suitable for processing on automatic lines. Consequently, most steel-related prefabricated housing manufacturers in Japan have adopted these products as beams for their houses.
2. Background behind the adoption of SMart BEAM™
When ground roads are running below elevated roads, sound absorbing panels for the underside of elevated roads are installed in order to prevent automobile noise generated by ground roads to be reflected on the underside of elevated bridges and spread to the neighborhood. They are fitted to supporting H-beams suspended from bridge girders.
Supporting beams are fitted to bridges normally with human power, not by machines. The weight of one supporting beam with a length of approximately 5 meters is 100 kilograms or more in the case of rolled H-beams. However, by changing the steel material from rolled H-shaped steel to lightweight welded H-shaped steel, it is possible to reduce the weight by a maximum of roughly 40%, which also improves installation work efficiency and safety.
As these merits have been highly acclaimed, Sumitomo Metals' SMart BEAM™ lightweight welded H-beams have been used in a large quantity as supporting beams for the installation of sound absorbing panels for elevated roads of the Second Keihan Highway.
3. Outline of construction work
a.Construction work location: Hirakata-higashi - Kadoma Junction (Osaka Prefecture)
b.Orderer: Kansai Branch, West Nippon Expressway Company Limited
c.Construction firms: Sho-Bond Corporation, KFC, Ltd, and others (total of 7 firms)
d.Construction period: October 2008 - March 2010
4. Future business development
By leveraging the merits of lightweight welded H-beams, Sumitomo Metals will promote the expansion of sales of the SMart BEAM™ as beams supporting sound absorbing panels for the underside of elevated roads.
*Section properties: The strength of structural components and materials used in pillars and beams varies due to their shape, especially the shape of their cross-sections. The strength of components and materials that is determined by the shape of their cross-sections is called section properties.
Diagram and photos for reference
Fig.1: Structural model for installation of sound absorbing panels for underside of elevated roads
Fig.2: Upper side of sound absorbing panel for underside of elevated road and supporting beam
Fig.3: External view of sound absorbing panels for underside of elevated road after installation