Prestressing Steel Technology Supported the Shin-Meishin Project
Youbaizan Viaduct (Photo courtesy of Sumitomo Mitsui Construction Co., Ltd.)
Mukogawa Bridge, Aigawa Bridge and Youbaizan Viaduct
Extraordinarily large construction work with simultaneous operations of 32 form travelers
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."
Delivering high-strength prestressing steel strands to the construction site on a just-in-time basis
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).
From left
Yuka Kishimoto
"I was involved in the development of new technology for high-strength prestressing steel strand. I will continue to work for innovations in the production technology and the development of new products."
Shinji Nakaue
"I was in charge of the design and development of the anchorage system. My goal is to create a new technology that contributes to advanced prestressed concrete construction work."
Hisashi Nakatani
"I was responsible for sales and product delivery for Youbaizan Viaduct. I have a special attachment to the project because I have been involved in it since the completion of the bridge piers."
Shuichi Tanaka
"I was in charge of production technology and mass production of high-strength prestressing steel strand. I feel rewarded as an engineer that I was able to contribute to the widespread use of the products."
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