Segmental Cantilever Bridge Construction Case Study

The cast-in-place segmental cantilever construction method, further to its well-known advantages for long span bridge construction in general, does provide appropriate means to satisfy local needs for relatively long spans in an urban environment, practically without infringing on traffic or property below. Detailed are the structural considerations and construction challenges in the use of segmental cantilever bridges in two such urban environment cases for the Los Angeles County Metropolitan Transit Authority Metro Rail System. The Kramer Bridge is a continuous four-span box girder bridge 189 m (620 ft) long spanning over what previously was a hazardous-waste site. The Rosecrans Bridge is a continuous three-span box girder bridge 204 m (670 ft) long spanning diagonally over a busy city intersection. Despite difficulties experienced in the piling, cantilever, alignment, and closure operations, the cast-in-place segmental cantilever construction method allowed fast and economically competitive construction of two aesthetically pleasing structures.