Youbaizan Viaduct (Photo courtesy of Sumitomo Mitsui Construction Co., Ltd.)
Supply 1,000 tons of high-strength prestressing steel strand in a timely manner
Youbaizan Viaduct is a long bridge with both inbound lane and outbound lane exceeding 1,100 m long. While the free cantilever method was applied to the bridge as in the cases of Aigawa Bridge and Mukogawa Bridge, there was a major challenge unique to Youbaizan Viaduct that was not relevant to the other two bridges. Mr. Kenichi Kata from Sumitomo Mitsui Construction was in charge of the design and construction.
"The construction work of this bridge was so huge that 32 form travelers were used simultaneously at the busiest time while around 10 form travelers are used in ordinary work. No trouble was allowed in such simultaneous operations because the suspension of work on any of the sites could affect the whole process. The construction abilities were put to the test in the project. In addition, the timely and prompt supply of prestressing steel strand was essential to proceed with the work."
While the proper and prompt supply of steel strands was an absolute mission, the mega Youbaizan Viaduct required about 1,000 tons of high-strength prestressing steel strands. The fact that the total quantity of the high-strength prestressing steel strand shipped by Sumitomo Electric over 10 years was about 3,000 tons indicates the large scale of the project. In addition, it was not enough to just produce and transport the strands. It was necessary to supply only the needed volume of the strands only when they were needed because the construction site had no space to store such a large amount of materials. We were required to supply them literally in a just-in-time manner. To meet the demand, we carefully made a production and delivery plan even in consideration of unexpected circumstances in the land transportation and controlled the delivery while examining the progress of the construction work.
"Sumitomo Electric responded to the demand perfectly. I feel that it is a result of the trust relationship that has been developed between the two companies. A future challenge is the downsizing and weight saving of the equipment used at the construction site. When the scale of construction work becomes larger, the total volume of materials increases. Downsized equipment will accelerate the improvement of productivity on construction sites. We would like to generate innovations that change the construction sites drastically together with Sumitomo Electric." (Mr. Kata mentioned above).