NEW DESIGN FOR LONG-SPAN BRIDGES

A new design and construction technique for long-span concrete bridges, increasingly being used in the United Stats and Canada, is outlined. The design uses the post-tensioned hollow box girder. The technique that makes the long span practical is segmental construction. In many cases the segments are erected by a cantilever procedure that permits working in both directions from each pier and eliminates all falsework. In other cases, cable-stayed girders support the longer spans.