Construction of a Shinkansen viaduct using high-performance lightweight concrete

Numakunai Bi is a 395 m long Shinkansen girder viaduct, located 527.980 km from Tokyo. Its superstructure is composed of 11-span continuous prestressed concrete box girders and a reinforced concrete simple T-girder. For the box girders, a large amount of high-performance artificial lightweight aggregate was used as coarse aggregate in the concrete. This is the first attempt in Japan. The substructure of the section crossing over the Tohoku Honsen conventional railway was designed with portal steel rigid frame piers. These piers were made of CFTs (concrete filled steel tubes). The other piers were constructed with steel and reinforced concrete, using ribbed wide flange beams, to shorten the work period. The foundations are large-diameter caisson type piles for all the piers. This paper reports the design of the superstructure and substructure, and the construction of the superstructure.