Canton Viaduct Replacement

ALA provided design services for the replacement of Canton Viaduct, which carries I-895 over I-95 ramps, railroads and city streets, in Baltimore City. The existing structure, which was built in 1958, was in poor condition and some bridge elements did not meet design codes requirements for current loads. The new mainline northbound and southbound structures are approximately 3,300 feet long each, and consist of multi-girder continuous-span steel superstructure units supported by reinforced concrete wall piers on footings supported on piles.

ALA was tasked with the design of the abutments and 12 battered-stem wall piers for the mainline bridges. Due to the poor soil conditions, the abutment and pier footings are supported on micropile foundations. Design and detailing had to accommodate phased demolition and construction, geometric constraints and heavy skews up to 47 degrees. In addition to the mainline viaduct scope of work, ALA designed the bridge for the Holabird Avenue Off-Ramp and a retaining wall structure to support a vehicle inspection area at the south end of the southbound mainline bridge.

There were multiple design challenges particular to this project. Phased construction was used to maintain at least three out of four lanes of traffic during the project. There were myriad geometric and right-of-way constraints as the structure crosses over several roads and railroad tracks and under I-95, and additionally runs near several buildings.

Location: Baltimore, MD

Owner: MDTA