Vigil-Agrimis Inc (VAI), as part of a design-build team along with T.Y. Lin International and Kiewit Construction, is assisting Trimet with development of the new Willamette River Transit Bridge. The new bridge will carry light rail, buses, cyclists, pedestrians, and streetcars across the Willamette River between the existing Ross Island Bridge and Marquam (I-5) Bridge. VAI’s contribution to the team includes:

Analyzing bridge hydraulics
Designing scour protection
Designing stormwater conveyance and treatment, and
Coordinating local and city permitting.

Our team was selected by TriMet to move the bridge from 30% design to construction. During the selection process our team evaluated the 30% design and developed innovative additions and improvements which were and presented to the selection committee. VAI is conducting preliminary scour analysis and developed preliminary scour protection to support this effort.

The bridge is being constructed on and near contaminated soils along the banks of the Willamette River, and in close proximity to vital utilities requiring limited scour to occur due to the new bridge structure. VAI estimated potential scour using standard methods and existing scour documentation at both the Ross Island Bridge and Marquam (I-5) Bridges. Preliminary scour protection measures included designing articulated concrete block placement along the channel bed of the Willamette River. The project is expected to be constructed by 2015.