THE CABLE-STAYED MEIKO GRAND BRIDGES, NAGOYA

This article describes the design and, briefly, the construction of three large three-span cable-stayed bridges across three wide channels of Nagoya Port (Meiko) in Japan. All three bridges are on the Ise Bay Coastal Highway, which links several regional expressways. The centre spans of the West, Central, and East Meiko Bridges are 405m, 590m, and 440m, respectively. The highway has six traffic lanes and a central reserve; the West Meiko Bridge is actually two similar parallel bridges, each carrying three lanes, of which one was built in 1985. Steel cable-stayed bridges were selected, because of the rather unfavourable ground conditions and the required navigation clearances. The use of steel for the bridge towers and girders was also partly due to ground conditions, seismic considerations, shorter construction duration, and considerable previous experience with cable-stayed bridges in Japan. All the tower foundations are 40-55m deep pneumatic caissons. All bridges use a semi-fan-shaped, two-plane, multi-stay cable arrangement. Various measures were adopted to control vibrations in the cables due to wind and rain. All main girders have a streamlined, trapezoidal box cross section with triangular fairings, and an orthotropic steel deck. The superstructures were almost wholly created by staging and cantilevering.